138 Figure 1: A biogas processing system Source: Kheang et al. (2011) Table 1: Biogas composition Composition Symbol Percentage (%) Methane CH4 50 - 70 Carbon Dioxide CO2 30 – 40 Hydrogen H2 5 – 10 Nitrogen N2 1 – 2 Water Vapour H2O 0.3 Oxygen O2 0 – 2 Ammonia NH3 0 – 1 Hydrogen Sulphide H2S 217 – 1418 ppm Source: Nallamothu et al. (2013) and Kheang et al. (2011) 2. LITERATURE REVIEW Methane (CH4) from the biogas processing plant is used as one of the sources of fuel for biogas engines in the electricity generation industry. The biogas engine is a modification of a diesel engine and operates based on the Otto Cycle but works at a higher combustion temperature. Thus, the engine requires a special formulation of lubrication oil for safe, economical, and best operation. The lubricant used for biogas engines is basically made of base oil and a combination of several additives for several operating purposes. The base oil without additives has limited functions. Amongst additives are anti-oxidant, anti-wear, corrosion inhibitor, detergent and viscosity modifier (Nindhia et al., 2017). The lubrication oil acts as a film of barrier between moving parts of an engine, to reduce friction and wear, as a coolant to dissipate heat originated from combustion, as corrosion prevention, to avoid deposits of harmful constituents, and a few other functions. Nowadays, there is no real-time online monitoring system put in place to monitor the lubrication oil condition and its health due to certain constraints such as it being very costly,
139 not very reliable and lack of technology and suitable sensors (Agoston et al., 2005) and (Agoston et al., 2007). The operator adopts manual oil sampling to monitor the oil condition before any decision is made regarding engine oil change time interval. Manual oil sampling is chosen as a part of predictive-based maintenance (PdM) for improving engine efficiency. In the oil analysis, among the main parameters taken into consideration are base number (BN), acid number (AN), IpH, kinematic viscosity, viscosity index (VI), oxidation and nitration (Yadav et al, 2017), (Sikora & Miller, 2012) and (Wolak et al, 2022).Base number (BN) is an indication of reserve alkalinity in a lubrication oil that is capable of neutralizing any acidic impurities. The drop in base number manifests high acidic impurities holding in the lubrication oil that passes through the piston and the decrease of detergent/dispersant available to neutralize the acid. The acid number is an indication of the presence of acidic compounds in the oil as a result of oxidation and the formation of acidic byproducts. It covers both strong and weak acids, organic and inorganic acids. IpH comes in as a complementary to acid number. It indicates the acid strength in the oil which directly causes corrosion. Kinematic viscosity is a parameter related to the resistance to gravity flow of a fluid. The viscosity index is a measure of the ability of engine oil to resist becoming thinner at higher temperatures. Oxidation is a product of a reaction between basic oil and ingredient molecules in the presence of oxygen and heat. Nitration is a product of a reaction between basic oil and ingredient molecules in the presence of nitrogen oxides originating from blow-by gases passing into the crankcase. A lubrication oil change is carried out before it loses protective properties. Thus, oil sampling can monitor those properties accordingly. For an engine using natural gas as fuel, the oil change interval is found between 500 hrs and 1500 hours of operating. In one experiment by (Sen et al., 2012), it was found that at 750 hrs, the sensor signal used to monitor the acidity level started to be removed from its layer and the total loss of layer after 1300 hrs. It was corresponding to the critical amount of acid number between 2 and 2.5 in which significant onset of corrosion when the degree of oil degradation reached the amount of acids. Thus, acidification is one of the main parameters to monitor for the evaluation of oil conditions. The second finding suggested that at 2200 hrs of engine operation, the whole sensor’s metal corroded due to acidification hours (Schneidhofer et al., 2011). The critical limit for those parameters are varying by OEM. 3. METHODOLOGY For the study, a biogas engine installed in a biogas power plant located in the state of Perak, the northern region of Peninsular Malaysia was chosen. Field oil sampling was selected as the method of research. An oil sample of 100 mL is taken from the oil sampling point then specially packed and couried to a laboratory in Singapore for analysis. Within three to four days, the result will be emailed to the corresponding plant personnel for further action and comments. Table 2 shows the specification for the biogas engine used in the study. The engine uses Nateria MH 40 from TOTAL as the lubrication oil. Table 3 shows the detailed parameters of the lubrication oil. For this study, the maximum time interval for an oil change of 2000 hrs was chosen for an oil change but if the parameters exceed the set limits, the oil change must be done earlier. A previous study suggested that a decrease in the base number of half of the fresh oil or a minimum of 3, as for acid number is a maximum of 2.5 mgKOH/g from new oil, an increase of one-quarter from fresh oil for viscosity, a minimum of 4.5 for IpH and nitration of 20 A/cm.
140 Table 2: Biogas engine technical specification Item Unit Value Manufacturer Jenbacher Engine type J 416 Configuration V 700 No. of cylinder 16 Mechanical output kW 1.234 Electrical output kW 1.202 Displacement Litre 48.88 Nominal speed rpm 1500 Compression ratio 12.5 Lubrication oil capacity Litre 360 Source: Clarke Energy Table 3:Nateria MH 40 lubrication oil parameters for gas engine Parameter Unit Value SAE Grade 40 Density at 150C kg/m3 890 Kinematic Viscosity at 400C mm2 /s 142.2 Kinematic Viscosity at 1000C mm2 /s 18.5 Viscosity Index 105 Base Number (BN) mgKOH/g 5.5 Source: Finol Oils (2017) 4. RESULT AND DISCUSSION During the period of study, lubrication oil change was carried out nine times. A1 to A6 represent the oil change at or close to 2000 hrs of oil after in-service while B1 to B3 represent the oil change at or close to 1500 hrs of oil. Refer to Figure 2 and Figure 3 for detail. For 2000 hrs of the oil change, it is noticed that 35 – 40 % drop in base number compared to the fresh oil, a 60 – 100 % increase in acid number, a 40 – 50 % drop in IpH, 15 – 20 % increase in kinematic viscosity and nearly 10 A/cm of nitration. As for 1500 hrs oil change, it was done due to high nitrogen oxide (NOx) (B1), on scheduled maintenance – 10000 hrs engine operating hours (B2) and unknown reason (B3). In Figure 4, it is indicated the correlation between those parameters and lubrication oil operating hours. An exponential increase with operating time, BN drop as power curves, viscosity index and IpH decrease linearly with operating time while kinematic viscosity and nitration increase as a linear graph. As the operating time increases, a high amount of hydrogen sulphide (H2S) in biogas fuel slowly builds up acidic sulphate (Fulton, 1991). This activity combined with the high level of oxidation in the engine causes an increase in the acidity level and oil viscosity. This is because different acidic compounds from combustion gases and byproducts contaminated the oil. So, lubrication oil efficiency drops due to contaminants.
141 Biogas in nature contains corrosive hydrogen sulphide, which introduces extra stress on the oil in terms of its ability to neutralise acids. Hydrogen fluoride and hydrogen chloride are also typically found in landfill gas. During the combustion process and when combines with water, these compounds can form sulphuric acid, hydrofluoric acid or hydrochloric acid, all of which are highly corrosive to engine components such as liners, piston rings, piston ring grooves and bearings. Figure 2: Plot of lubrication oil operating hours, BN, AN, IpH and Nitration for the period of study Figure 3: Plot of lubrication oil operating hour, VI and viscosity for the period of study
142 Figure 4: Plot of AN, BN, IpH, VI, viscosity and nitration against lubrication oil operating hour 5. CONCLUSION The engine has successfully operated based on 2000 hrs oil change formulated from previous research done by (Schneidhofer et al., 2011) and (Sen et al., 2012). Among important parameters to be considered in the lubrication oil analysis are base number (BN), acid number (AN), IpH, kinematic viscosity, viscosity index (VI), oxidation and nitration. Any glitch out of range of those parameters must trigger an immediate lubrication oil change. Also, oil samplings must be carried out as planned (500, 1000, 1500 and 2000 hrs of operation). It is an essential process in establishing the oil condition since it indicates whether the additives are still capable of providing sufficient engine protection. ACKNOWLEDGEMENT The author would like to thank all the biogas plant personnel for their support, knowledge and data sharing and guidance for the success of this study.
143 REFERENCE Agoston, A., Otsch, C. & Jakoby, B. (2005). Viscosity sensors for engine oil condition monitoring— Application and interpretation of results. Sensors and Actuators A, 121, 327 - 332. doi:10.1016/j.sna.2005.02.024 Agoston, A., Dorr, N. & Jakoby, B. (2007). Corrosion sensors for engine oils—laboratory evaluation and field tests. Sensors and Actuators B, 127, 15 – 21. doi:10.1016/j.snb.2007.07.041 Bertinatto, R., Friedrich, L., Bariccati, R. A., Meleggari, S. M., Gurgacz, F. & Pazuch, F. A. (2017). Analysis of lubricant oil contamination and degradation and wear of a biogas-fed otto cycle engine. Acta Scientiarum Technology, 39(4), 409 – 416. Doi: 10.4025/actascitechnol.v39i4.29458 Fulton, A. C.(1991). The effect of hydrogen sulphide on CHP engines at Countess Wear WewageTreatment Works, Exeter. Water and Enviroemntal Journal, 5(2), 172 – 177. Kheang, L.S., Dazhi, L.L., Sukiran, M.A. & May, C.Y. (2011). A biogas trapping facility for handling palm oil mill effluent (POME). MPOB Information Series, 564(491). ISSN 1511-7871 Nallamothu, R. B., Teferra, A., & Rao, B. V. (2013). Biogas purification, compression and bottling. Global Journal of Engineering, Design & Technology, 2(6), 34 – 38. ISSN: 2319 - 7293 Madaki, Y.S. & Seng, L. (2013). Palm oil mill effluent (pome) from Malaysia palm oil mills: waste or resource. International Journal of Science, Environment and Technology, 2(6), 1138 – 1155. ISSN 2278-3687 (O) Nindhia, T. T., Surata, I. W. & Wardana, A. (2017). The effect of biogas desulfurization to acidity of lubricant oil of the biogas fuelled engine. IOP Conference Series: Material Science and Engineering, 201 (2017) 012021. doi:10.1088/1757-899X/201/1/012021 https://doi.org/10.1111/j.1747-6593.1991.tb00604.x Sikora, G. & Miller, H. (2012). The analysis of changes in total base number and the flash point in the exploited engine oil. Journal of KONES Powertrain and Transport, 19(3). Sen, S., Schneidhofer, C., & Dorr, N. (2012). Online monitoring of the oil acidification using a chemical sensor measuring corrosiveness. Prodecia Engineering, 47, 466 – 469. doi: 10.1016/j.proeng.2012.09.185 Trisakti, B., Manalu, V., Taslim, I. & Turmuzi, M. (2015). Acidogenesis of Palm Oil Mill Effluent to Produce Biogas: Effect of Hydraulic Retention Time and pH. Procedia Social and Behavioral Sciences, 195, 2466 – 2474. doi: 10.1016/j.sbspro.2015.06.293 Yadav, G., Tiwari, S., Jatola, R. & Jain, M. L. (2017). Experimental Investigation of Lubricating Properties of Engine Oil. International Journal of Engineering Science and Computing, 7(4). Wolak, A., Molenda, J., Fijorek, K. & Lankiewicz, B. (2022). Prediction of the total base number (TBN) of engine oil by means of FTIR spectroscopy. Energies, 15(2809). https://doi.org/10.3390/en15082809 Schneidhofer, C., Sen, S. & Dorr, N. (2011). Determination of the Impact Of Biogas on the Engine Oil Condition Using a Sensor Based on Corrosiveness. In Bernardes, M. A., Biofuel Production-Recent Developments and Prospects. IntechOpen. DOI: 10.5772/20288
144 KAJIAN TAHAP PENGUASAAN PELAJAR DALAM MENENTUKAN PUSINGAN DAYA DAN JARAK SERENJANG DALAM PERSAMAAN MOMEN BAGI KURSUS DJJ30093 – ENGINEERING MECHANICS Sarina binti Ishak1* Nurul Hidayah binti Hamdan2 1-2Politeknik Seberang Perai, Pulau Pinang. *Emel: [email protected] ABSTRAK Momen ialah ungkapan matematik yang melibatkan daya didarab dengan jarak serenjang dari garis tindakan daya ke titik di mana objek akan berpusing. Keupayaan menentukan daya dan arah momen merupakan asas yang penting dalam penyelesaian masalah Structure Analysis yang terkandung dalam silibus kursus DJJ30093 Engineering Mechanics di Politeknik Malaysia. Masalah yang dikenalpasti dihadapi oleh pelajar adalah mereka sukar menentukan arah pusingan daya dan jarak serenjang. Melalui permasalahan yang dikenalpasti, kajian ini memfokuskan kepada tahap penguasaan pelajar dalam menentukan pusingan daya dan jarak serenjang dalam persamaan momen. Tinjauan masalah dilakukan melalui kaedah pemerhatian, temubual dan pengisian Google Form yang dijalankan kepada pelajar seramai 53 orang bagi Sesi 1 2022/2023. Sebanyak lima soalan telah dijawab oleh pelajar berkenaan penggunaan momen. Hasil dapatan utama daripada kajian yang dilakukan mendapati 49% pelajar tidak pasti bagi menentukan pusingan momen, samaada mengikut pusingan jam atau sebaliknya. Manakala 60% pelajar pula tidak pasti bagi menentukan jarak serenjang yang perlu diambil apabila melibatkan persamaan momen. Akhir sekali sebanyak 91% pelajar bersetuju sekiranya dibina satu Model Kit bagi membantu pelajar memahami momen dengan lebih berkesan. Cadangan bagi menambahbaik penggunaan momen ini perlu diselaraskan bagi kesemua pelajar yang mengambil kursus DJJ30093 supaya keberkesanannya dapat diuji dengan lebih baik. Cadangan penggunaan Moment Kit diharap dapat menambahkan lagi kefahaman pelajar dalam memahami topik Structure Analysis. Kata Kunci: Momen, Jarak Serenjang, Engineering Mechanics, Structure Analysis. 1. PENGENALAN Fizik adalah salah satu cabang ilmu sains yang digunakan untuk menyelesaiakan permasalahan harian. Menurut Kamus Dewan Edisi Keempat, Fizik adalah cabang ilmu sains yg mengkaji sifat-sifat jirim dan tenaga seperti haba, cahaya, bunyi, graviti, magnetisme dan perkaitan antara semua unsur ini. Penguasaan ilmu Fizik adalah amat penting bagi pelajar yang mengikuti pengajian Kejuruteraan di Politeknik. Antara kursus kejuruteraan yang menggunapakai konsep Fizik adalah Mechanics of Fluids, Strength of Material, Engineering Mechanics dan beberapa lagi kursus lain. Bagi kursus DJJ30093 Engineering Mechanics, pemahaman yang tinggi diperlukan bagi membolehkan pelajar memahami salah satu topik yang diaplikasikan dalam persamaan momen bagi topik 4 iaitu Structure Analysis. Terdapat dua kaedah utama yang perlu digunakan oleh pelajar bagi mendapatkan nilai daya iaitu: a) Method of Joint b) Method of Section Sebelum mendapatkan nilai daya, pelajar perlulah mahir bagi menggunakan persamaan momen. Selain minat, pelajar juga harus membuat banyak latihan berasaskan momen kerana terdapat pelbagai kaedah dalam memahami momen. Minat pelajar terhadap fizik ialah satu faktor utama bagi pelajar untuk memahami konsep fizik dan mengaplikasinya dalam menyelesaikan masalah (Ornek et al., 2007)
145 Momen adalah antara salah satu asas yang perlu dipelajari dalam Fizik. Momen kesan putaran yang dihasilkan apabila daya dikenakan pada satu objek pada satu titik yang tetap. Terdapat dua faktor yang mempengaruhi momen iaitu daya yang dikenakan dan jarak tetap dari fulkrum ke daya. Rajah 1 menunjukkan gambaran spanar yang digunakan apabila mengetatkan nut. Apabila daya F dikenakan, ia akan menyebabkan spanar berpusing dan secara teorinya akan melalui jarak d. Hasil kilasan yang dihasilkan adalah momen mengikut konsep Fizik. Rajah 1: Momen Secara asasnya, formula yang dapat menghubungkaitkan persamaan momen adalah daya didarab dengan jarak yang dilalui semasa proses kilasan berlaku. Jika diteliti dengan lebih mendalam, daya yang dikenakan perlu diambil kira samaada ianya mengikut arah putaran jam atau melawan arah putaran jam, manakala bagi jarak yang dilalui ianya perlulah serenjang daripada paksi putaran. Rajah 2 menunjukkan formula momen dimana daya yang dipusing dikira positif atau negatifnya bergantung kepada putaran yang dibuat, manakala bagi jarak ia mestilah serenjang atau bersudut 90° daripada titik tetapnya. Rajah 2: Formula momen Hasil pembelajaran yang dijalankan didalam kelas, tahap kognitif yang diuji bagi topik 4 adalah pada aras C3 sehingga C4. Tahap kognitif ini menunjukkan ia adalah aras yang tinggi dan memerlukan pelajar membuat penyelesaian masalah bagi soalan yang diberi. Bagi persamaan momen, pelajar dikenalpasti masih lagi tidak mahir dalam menentukan pusingan daya dan jarak yang perlu diambil. jarak serenjang dari pangsi ▪ Daya mengikut pusingan jam = positif ▪ Daya melawan pusingan jam = negatif Daya x Jarak Momen
146 Menurut Kajian Pustaka, kognitif adalah adalah kemampuan individu yang berhubungan dengan aktiviti mental seperti persepsi, pemikiran, ingatan, pemahaman dan pertimbangan yang digunakan dalam pengolahan suatu maklumat, mendapatkan pengetahuan, beradaptasi terhadap lingkungannya, pemecahan suatu masalah dan merencanakan masa depan. Kajian tahap penguasaan pelajar dalam menentukan pusingan daya dan jarak serenjang dalam persamaan momen bagi kursus DJJ30093 – Engineering Mechanics diharap dapat membantu pengajar bagi memberi pemahaman kepada pelajar dalam memahami momen dengan lebih baik. 2. LATAR BELAKANG KAJIAN Kursus DJJ30093 - Engineering Mechanics adalah kursus yang perlu diambil oleh pelajar pada semester 3. Topik yang dipelajari dalam kursus ini adalah mengaplikasikan Hukum Newton, dimana salah satu persamaan yang selalu menjadi kekeliruan kepada pelajar semasa penyelesaian masalah adalah pada persamaan momen. Noormala, Suhana, Azila, (2013) menyatakan penguasaan yang baik dapat membantu pelajar bagi penyelesaian masalah yang berkaitan. Menurut kajian yang dijalankan oleh Lilia et. al (2002) mendapati topik mekanik merupakan salah satu kursus fizik yang sukar difahami oleh pelajar. Ini kerana topik mekanik banyak menggunakan persamaan matematik dalam menerangkan fenomena fizikal. Jadi, sebelum memahami sesuatu soalan yang diberi, pelajar harus tahu untuk membuat persamaan matematik bagi membolehkan penyelesaian masalah dilakukan. Melalui kajian yang dilakukan, mendapati penguasaan dalam ilmu fizik, salah satunya adalah momen sangat penting bagi topik Structure Analysis memandangkan ianya adalah topik utama bagi Bab 4. Jika dihubungkaitkan dengan Coursework Item Specification Table (CIST), bagi penilaian topik Structure Analysis, Course Learning Outcome (CLO) yang dinilai adalah pada CLO2, manakala tahap kognitif yang dinilai adalah pada C3 dan C4, dimana pelajar perlu membuat menyelesaikan masalah dan membuat analisa berdasarkan kedua-dua kaedah utama yang digunakan iaitu Method of Joint dan Method of Section. Menurut Hayes dan Allison, (1998), gaya kognitif merujuk kepada cara seseorang memperoleh, memproses dan menilai sesuatu maklumat yang diterima. Gaya ini mempengaruhi cara seseorang mengimbas dan memerhati persekitaran untuk mendapatkan maklumat, cara menyusun dan mentafsir maklumat tersebut serta cara mengintegrasikan pentafsiran mereka dalam bentuk peta minda serta teori yang akan merangsang tindakan seterusnya. Jadi kognitif pada tahap C3 dan C4 merupakan kognitif pada aras yang agak tinggi dan memerlukan pemahaman yang tinggi daripada pelajar. Bagi mendapatkan maklumat berkenaan penguasaan pelajar dalam persamaan momen, temubual dijalankan keatas pelajar di Jabatan Kejuruteraan Mekanikal bagi kelas DKM3C dan DMT3A yang mengikuti kursus DJJ30093 pada sesi Sesi 1 2022/2023, menjadikan jumlah data yang dikumpul adalah 53 data. Selain itu, edaran soal selidik juga dilakukan melalui Google Forms. Sebanyak lima soalan telah disoal bagi mendapatkan maklumat untuk mengenal pasti bahagian yang paling sukar difahami oleh pelajar dalam persamaan momen.
147 3. OBJEKTIF KAJIAN Objektif bagi kajian adalah: a. Mengetahui penguasaan pelajar bagi menentukan pusingan momen, samaada mengikut pusingan jam atau melawan pusingan jam. b. Mengetahui penguasaan pelajar bagi menentukan jarak serenjang yang perlu diambil. 4. PENGUMPULAN DATA Hasil daripada kajian awal melalui temubual dengan pelajar, beberapa perkara telah dikupas. Sebilangan besar pelajar mengadu agak sukar mengenal pasti arah momen serta mereka masih keliru memilih jarak serenjang yang betul semasa latihan dan juga End of Chapter. Selain itu, semasa penerangan diberikan oleh pensyarah di dalam kelas, pelajar mengakui mereka faham konsep yang diajar. Namun apabila mereka cuba membuat latihan yang diberi secara individu atau berkumpulan, mereka masih ragu-ragu dan perlu bertanya semula untuk kepastian samaada arah momen dan jarak yang diambil tersebut adalah betul atau tidak. Hal ini membuktikan pelajar masih belum dapat menguasai dengan tepat bagi menentukan arah momen dan jarak serenjang. Selain daripada temubual,soal selidik juga dijalankan melalui edaran Google Forms. Dapatan daripada soal selidik mendapati pelajar masih lemah dalam menggunakan persamaan momen. Pelajar keliru bagaimana pusingan daya akan berlaku, samaada mengikut pusingan jam atau melawan pusingan jam, selain untuk menentukan jarak yang bersudut 90 darjah daripada titik tetap. Terdapat lima soalan utama diajukan dimana ia mengfokuskan perkara yang berkaitan asas penggunaan momen. Jadual 1 menunjukkan edaran soalan yang ditanya: Jadual 1: Soalan yang diedar melalui Google Forms Soalan Pernyataan Soalan 1 Saya tahu persamaan asas momen. Soalan 2 Saya tahu formula momen yang digunakan semasa PNP. Soalan 3 Saya dapat menentukan dengan mudah pusingan momen, samaada mengikut pusingan jam atau melawan pusingan jam. Soalan 4 Saya tahu menentukan jarak yang perlu diambil apabila melibatkan persamaan momen. Soalan 5 Saya bersetuju sekiranya dibina satu Alat Bantu Mengajar atau Kit Pembelajaran yang digunakan bagi membantu pelajar memahami momen dengan lebih berkesan. Skala Likert digunakan yang bertujuan mengukur sikap, pendapat dan persepsi seseorang atau sekelompok orang tentang kejadian atau gejala sosial. Setiap maklumat yang diberikan akan dihubungkan dalam bentuk pernyaan seperti Jadual 2 dibawah: Jadual 2: Skala Likert Skala Pernyataan 1 Sangat Tidak Setuju 2 Tidak Setuju 3 Tidak Pasti 4 Setuju 5 Sangat Setuju
148 5. DATA ANALISIS Data yang dikumpul seterusnya dianalisa dengan menggunakan Microsoft Excel bagi mendapatkan nilai peratus kekerapan bagi setiap pernyataan seperti di Jadual 4. Pengiraan peratus kekerapan bagi skala 1 dan 2 digabungkan bersama iaitu Sangat Tidak Setuju dan Tidak Setuju,skala 3 iaitu Tidak Pasti, serta skala 4 dan 5 digabungkan bagi Setuju dan Sangat Setuju. Setelah selesai edaran soalan melalui Google Forms, data dikumpul bagi menilai kekerapan pada setiap soalan seperti yang ditunjukkan pada Jadual 3 dibawah. Jadual 3: Jadual kekerapan mengikut soalan Item Kekerapan 1 2 3 4 5 Soalan 1 0 0 7 26 20 Soalan 2 0 1 10 27 15 Soalan 3 18 4 26 2 3 Soalan 4 11 2 32 1 7 Soalan 5 0 1 4 12 36 Fokus soal selidik ini adalah pada soalan 3 dan soalan 4, dimana ia menguji kefahaman pelajar dalam menentukan daya dan jarak. Secara kasarnya, didapati pelajar tidak mencapai tahap yang memuaskan dalam memahami momen. Jika dilihat pada Jadual 4 dibawah, bagi soalan 3 dan soalan 4, jumlah yang tidak bersetuju dan tidak pasti mendapat peratus yang tinggi berbanding peratus yang bersetuju. Jadual 4: Peratus Kekerapan Bagi menilai dengan lebih jelas, setiap peratus kekerapan diasingkan mengikut kategori Tidak Setuju, Tidak Pasti dan Setuju. Jadual 5 menunjukkan perbandingan setiap kategori tersebut. Bilangan bagi yang Tidak Pasti juga dikira kerana pada bahagian soalan 3 dan soalan 4, ia mendapat peratus yang tinggi berbanding peratus Tidak Setuju. Item 1 2 Jumlah yang tidak bersetuju 3 Jumlah yang tidak pasti 4 5 Jumlah yang bersetuju Kekerapan % Kekerapan % Kekerapan Kekerapan % Kekerapan % Soalan 1 0 0 0 0 0 7 13 26 49 20 38 87 Soalan 2 0 0 1 2 2 10 19 27 51 15 28 79 Soalan 3 18 34 4 8 42 26 49 2 4 3 6 9 Soalan 4 11 21 2 4 25 32 60 1 2 7 13 15 Soalan 5 0 0 1 2 2 4 8 12 23 36 68 91
149 Secara asasnya, berdasarkan soalan 1 dan soalan 2, pelajar telah mengetahui persamaan dan formula yang digunakan bagi momen iaitu daya didarab dengan jarak. Hal ini dapat dilihat pada soalan 2, peratus yang Setuju adalah 79% berbanding peratus yang Tidak Setuju iaitu 2%. Jadual 5: Perbandingan Peratus Kekerapan Bagi soalan 3, dimana ia menguji kefahaman pelajar bagi menentukan daya pusingan momen, sebanyak 42% pelajar tidak bersetuju mereka dapat menentukan pusingan momen samaada mengikut pusingan jam atau melawan pusingan jam, manakala terdapat 9% pelajar bersetuju dapat menentukan dengan mudah pusingan momen yang dibuat. Jika dilihat pada peratus yang Tidak Pasti, ia melebihi peratus yang Tidak bersetuju iaitu 49%. Hasil daripada temubual bersama pelajar, peratus yang Tidak Pasti ini menyatakan mereka selalu keliru untuk membuat pusingan momen selain tidak dapat mengenalpasti dengan tepat arah pusingan yang dibuat samaada dalam keadaan negatif atau positif. Bagi soalan 4 pula, yang mana ia menguji kefahaman pelajar bagi menentukan jarak serenjang, terdapat 25% pelajar tidak memahami bagaimana untuk mengambil jarak dengan betul, berbanding 15% lagi bersetuju. Peratus tertinggi sebanyak 60% bagi skala Tidak Pasti menunjukkan pelajar mempunyai masalah yang sama seperti di soalan 3 iaitu mereka lemah dalam menentukan jarak serenjang yang perlu diambil dengan tepat. Akhir sekali, bagi soalan 5, 91% pelajar bersetuju bagi mewujudkan satu Alat Bantu Mengajar (ABM) atau Kit Pembelajaran bagi membantu mereka untuk melihat dengan lebih jelas bagaimana daya dan jarak diambil untuk penyelesaian masalah yang diberi. Sebagaimana menurut Siti Sakinah (2018), ABM interaktif mampu menarik minat pelajar serta meningkatkan pemahaman dan prestasi pelajar dalam memahami sesuatu permasalahan .Hal ini menggambarkan pelajar memerlukan satu medium yang lebih jelas dalam memahami momen. No. Soalan % Kekerapan Tidak Setuju % Kekerapan Tidak Pasti % Kekerapan Setuju 1. Saya tahu persamaan asas momen. 0 13 87 2. Saya tahu formula momen yang digunakan semasa PNP. 2 19 79 3. Saya dapat menentukan dengan mudah pusingan momen, samaada mengikut pusingan jam atau melawan pusingan jam. 42 49 9 4. Saya tahu menentukan jarak yang perlu diambil apabila melibatkan persamaan momen. 25 60 15 5. Saya bersetuju sekiranya dibina satu Alat Bantu Mengajar atau Kit Pembelajaran yang digunakan bagi membantu pelajar memahami momen dengan lebih berkesan. 2 8 91
150 6. KESIMPULAN Berdasarkan analisa data yang dibuat, penekanan pada konsep asas momen perlu dijelaskan kepada pelajar bagi membantu mereka memahami asasnya terlebih dahulu terutamanya apabila melibatkan pemilihan daya dan jarak. Hal ini penting kerana di dalam topik Structure Analysis bagi kursus Engineering Mechanics, penggunaan bagi momen diaplikasikan di awal setiap jalan pengiraan, sekiranya pelajar tidak dapat menentukan momen dengan tepat, jawapan seterusnya akan memberikan kesan (Rokayah, Salmi, 2021). Hasil daripada kajian yang kebanyakannya bersetuju diwujudkan Alat Bantu Mengajar, satu kit akan dibina yang diberi nama Moment Kit. Alat ini merupakan satu alat sokongan bagi membantu pensyarah menunjukkan kepada pelajar secara lebih jelas bagaimana penggunaan momen diaplikasikan. Selain daripada bantuan kit, pensyarah juga perlu lebih kreatif dan lebih peka bagi memahamkan pelajar dalam menentukan pusingan daya dan jarak yang tepat dalam persamaan momen. Kesimpulannya, melalui kajian ini, kewujudan Alat Bantu Mengajar merupakan satu nilai tambah dalam meningkatkan tahap pencapaian pelajar bagi digunakan dalam sesi pengajaran dan pembelajaran serta sedikit sebanyak menggalakkan lagi kreativiti pensyarah bagi mewujudkan suasana pembelajaran yang lebih baik. RUJUKAN Ornek, F., Robinson, W. R. dan Haugam, M. R. (2007). What Make Physics Difficult? Science Education International. 18(3), 165-172. Rokayah, A. R., Salmi, A. (2021). Kit Moda: Meningkatkan tahap kemahiran dalam menentukan kuantiti vektor momen daya. Journal on Technical and Vocational Education (JTVE), Vol 6 No 2: Special Edition NARTC (2021). eISSN: 0128-0821 http://upikpolimas.edu.my/ojs/ Noormala, A., Suhana, R., Noor Azila, M. R., (2013). Pengaruh asas ilmu Fizik terhadap pencapaian akademik pelajar bagi kursus Sains Kejuruteraan sesi Disember 2013. Kamus Dewan (1991). Kuala Lumpur: Dewan Bahasa dan Pustaka. Siti Sakinah Mohd Yusof, Mazni Kohlit, Faizah Maarof, Amal Zunnairah Abu Bakar (2018) Keberkesanan penggunaan alat bantu mengajar interaktif dalam pengajaran dan pembelajaran asas pengaturcaraan. Jurnal Penyelidikan Dedikasi Jilid 15, 2018. Lilia Halim, T. Subahan M. Meerah, Zolkepeli Haron (2002). Strategi Pengajaran Fizik Untuk Guru Sains. Prentice Hall Pearson Malaysia Sdn. Bhd. Hasnah Mohamed, Zaidatun Tasir, Baharuddin Aris (2014). Pengaruh gaya kognitif terhadap pencapaian pelajar. Konvensyen Antarabangsa Jiwa Pendidik 2014, 11-13 Ogos 2014. Hayes J. and Allison C.W. (1998). Cognitive Style and The Theory And The Practice Of Individual And Collective Learning In Organizations. Human Relations. 51: 847 – 871.
151 PRODUCTION OF POROUS 316L STAINLESS STEEL USING DIFFERENT COMPOSITION OF SPACE HOLDER Zulaikha Abdullah1* Redza Izwan Abdul Rahman2 Che Susilawati Che Berahim3 1-3 Jabatan Kejuruteraan Mekanikal, Politeknik Mukah, Sarawak *Email: [email protected] ABSTRACT Porous metal are cellular solids made from metals consist of empty voids which called as pores. Researchers have shown an increased interest in porous metal due to their excellent in physical and mechanical properties. In this study, Porous 316L stainless steel was produced by using powder metallurgy route based on space holder technique. Stainless steel (SS316L) powder as metallic material, white urea as space holder, and polyethylene glycol (PEG) as binder was homogenously mixed using roller mixer before cold compacted using Uniaxial pressing machine and two-stage sintered at 870°C using Carbolite box furnace. The physical properties of porous 316L stainless steel is determined by conducting density and porosity test and the morphological properties of the foams is analysed by performing Scanning Electron Microscopy (SEM). The results indicate that, the composition of 25 wt. % produce high porosity of 316L stainless steel foams. The morphology of porous 316L stainless steel with the composition of 25 wt. % contain open pores compare to the other porous 316L stainless steel with 15wt. % and 20wt. %. Keywords: Cellular Metals, Austenitic Stainless Steel, Space Holder Method. 1. INTRODUCTION 1.1 Types of Porous Metal For many decades, they are numbers of research has been study in producing porous metals. Porous metals are lightweight metallic structures that possess a three-dimensional network of interconnected pores and contain 15 to 95% of volume pores throughout their structure. Porous metals have provided an excellent characteristic such as lower density with high porosity that make them lightweight, good mechanical properties such high strength and ductility, and great energy absorption capability. There are various applications of porous metals such as shock absorbers in automotive industries, catalysis and filtration due to its high surface area, heat exchangers and biomedical implants (Yi, et al., 2019). Porous metals are fabricated by combining different metals or adding elements to the base metal to enhance specific properties. The porous in the structure can be of varying sizes and shapes, and they can be either open-cell pores or closed -cell pores. Open-cell porous metals are consisted of interconnected pores throughout the material. These interconnected pores resemble an open-cell foam or sponge-like structure, hence the name "open-cell." The nature of interconnected open pores allows fluid, gases and other substances to flow freely and making it highly permeable and suitable for applications such as filtration, fluid transport and heat exchange (Kulshreshtha & Dhakad, 2020). Compared to open-cell porous metals, closed-cell porous metals do not have interconnected pores and the network of pores are more isolated.
152 Thus, fluids and gases cannot flow freely through the material. However, the closed-cell porous metals provide higher mechanical streghth that suitable for load-bearing and structural applications (Kulshreshtha & Dhakad, 2020). Figure 1 shows Microstructure of open-cell porous metals and closed-cell porous metals respectively (Zhou, 2006). Figure 1: Microstructure of open-cell porous metals(left) and closed-cell porous metals(right). Source: Zhou (2006) An austenitic stainless steel also known as 316L stainless steel (SS316L) have often used in marine, energy, aerospace, semiconductor and medical industries due to its excellent strength and corrosion resistance. Nowadays, SS316L used as biomaterials for orthopedic implant application due to its great mechanical properties, considerable biocompatibility and non-toxic and the cost much cheaper compared to other biomaterials (Meenashisundaram, et al., 2020). Furthermore, porous SS316L exhibit excellent properties includes high strength, low density, great mechanical and resistant to corrosion. Therefore, Porous stainless steel are widely used in different applications such as filter and catalysis, bio-implants and structural panel (Jain H. , Mondal, Gupta, Kumar, & Singh, 2020). Over the past years, there has been a series of production methods for porous metals. Among these, powder metallurgy (PM) route is more promising method to fabricate porous metals due to their the stability of the metals process in high-melting point can be achieve, simplicity of material handling, and offered wide range of alloying variation (Asavavisithchai , Preuksarattanawut, & Nisaratanaporn, 2014). PM route based on space holder technique produce porous metals by using space holder materials that act as pore former and also as a sacrificial material. The space holder technique consists of mixing process of metallic materials and space holder material, compaction of the mixture, and sintering process in order to remove the space holder and produce the porous structure (Smorygo, et al., 2012). The aim of the research is to fabricate the porous SS316L by using PM route based on space holder techniques by taking white urea as space holder materials. The sintered porous SS316L is then evaluated in order to study the influence of the composition of space holder material into the mixtures to the porosity of the porous SS316L. The physical properties of the porous SS316L were investigated and the morphology of the porous SS316L structure were analysed. 2. LITERATURE REVIEW 2.1 Fabrication Methods for Porous Metals Historically, since 1920s the fabrication of porous metals has been investigated.
153 There are various techniques to fabricate porous metals and classified into liquid metals, metal vapour, metal ions, and powdered metals. These techniques are designed to control the pore structure, size, and distribution to meet specific application requirements. Porous metals can be fabricated without applied any pressure or with pressure either in solid form or in powder form. The choice of fabrication method depends on the desired properties of the porous metal, including pore size, porosity, mechanical strength, and permeability (Singh & Bhatnagar, 2018). 2.2 Fabrication of Porous Metals from Liquid Metals There are two types of fabrication of porous metals from liquid metals which are direct foaming and indirect foaming. The most common method that used by among researchers are direct foaming by blowing agents. In this method, the metal is melted and the viscosity of melt are controlled by using viscosity enhancing material. Materials such as Stainless Steel and Graphite can be used in order to get the uniform mixing. Blowing agents are applied for blowing of gas in order to get the foaming effect. Blowing agents materials such metal hydrides, metal carbonates or metal oxides are used. It is important to make sure the decomposition temperature of blowing agent is matching with melting points of metals in order to get the better quality of resultant porous structure. After uniform mixing of blowing agents and the molten metals, the temperature were increased and when the temperature is reached to decomposition of temperature of blowing agents, it start to blow bubbles of gas and trapped inside melt before suddenly cooled and solidified (Patel, Bhingole, & Makwana, 2018). 2.3 Fabrication of Porous Metals from Metal Vapour Porous metals can be fabricated using Metal Vapour techniques. These techniques include fabricating polymer precursors by evaporation, chemical vapor deposition or by electrodeposition. Basically, metal is deposited on the polymeric sponge galvanically. For example, the polymeric sponge was coated with electric conductive material to produced thon coating layer so that, the polymeric foam can be in the stated on conductive. The properties of resultant porous metals depend on various factors such as the vaporization conditions, cooling rate, and the shape or structure of the polymeric sponge (Singh & Bhatnagar, 2018). 2.4 Fabrication of Porous Metals from Metal Ions Electrodeposition or electroplating involves the use of an electrolytic cell, where metal ions from a solution are reduced and deposited onto a conductive substrate, creating a metal coating with a controlled thickness and morphology. Theoretically, in electrodeposition process, metals precursors are electrochemically reduced to their solid metal states by direct transferring electrons from the working electrode. The generation of electrons, nucleation and the formation of crystal growth are influence by the potential applied on the electrode. The resultant of porous metals is controlled by these parameters (Li, et al., 2018). 2.5 Fabrication of Porous Metals from Powdered Metals Powder Metallurgy technique based on space holder method using space holder material as pore formers to produce porous metals. In general, space holder method consists of four main steps. The first step is to mix metal matrix powder with the space holder materials. It is important to make sure the mixture was mixed homogenously. Then, the mixture will go to the compaction process such as uniaxial die pressing, isostatic pressing and injection molding. The suitable compaction pressure must be applied in order to get the structure with sufficient strength to proceed to the next step. The next step, the space holder material will be removed using leaching method or other suitable space holder removal process.
154 Finally, the green compact will go to the sintering process to get the porous metals with great mechanical properties (Contreras, et al., 2021). In this research, the Powder Metallurgy technique based on space holder method was choose as fabrication method due to its simple process, cost-effective, easy to control pores structures and porosity level (Jain H. , Mondal, Gupta, Kumar, & Singh, 2020) 3. METHODOLOGY Spherical shape stainless steel type 316L powders purchased from Maju Scientific Sdn. Bhd. with the particle size approximately 7.157 µm was used as metallic material, white urea which is high soluble as the space holder material, and polyethylene glycol (PEG) was used as the binder. The compositions of urea particles in to the formulation are 15wt. %, 20wt. % and 25wt. % and PEG composition is 1wt. % fixed. All the materials were mixed using roller mixer 30minutes with speed of rotation was 100RPM before cold compacted using Carver conventional pressing machine with 3 tonnes pressure and holding time 5minutes, and the cylindrical mould with 14mm diameter in size and thickness 10mm was used as samples size. The samples were sintered using Carbolite box furnace to burnt off the urea particles at two stage sintering profile which are the first stage at 450°C with 30minutes holding time, and second stage at 870°C with 30minutes holding time to sinter the steel. The heating and cooling rate is 2˚C/min. Figure 2 illustrate the temperature profile for the sintering process. Archimedes principle was used to determined density and porosity of sintered porous SS316L, and Hitachi SU1510 scanning electron microscopy was used to analyze morphology of porous SS316L. Figure 2: Temperature Profile for Sintering Process 4. RESULT AND DISCUSSION Archimedes principles were applied in order to determine the density and porosity of the porous SS316L. Figure 3 shows the graph of bulk density and apparent porosity of porous SS316L versus of compositions of urea particles into the powder formulation. The density of porous SS316L is increase with the decreasing of composition of urea particles into the formulation. These result match those observed in earlier studies that the compositions of urea particles into the formulation influence the density of porous SS316L (Jain H. , Mondal, Gupta, & Kumar, 2021).
155 In contrast, the apparent porosity of porous SS316L increases with the increasing of composition of urea particles into the formulation. These results support previous research which the increasing of apparent porosity is inversely proportional to the composition of urea particles added up into the formulation (Jain H. , Mondal, Gupta, Kumar, & Singh, 2020). Figure 3: Graph of bulk density and apparent porosity of porous SS316L versus of compositions of urea particles into the powder formulation The morphology of porous SS316L is evaluated by performing scanning electron microscopy (SEM). Figure 4 shows the morphology of porous SS316L with composition of urea 15wt. % As can be seen from the figure, the pore distribution of porous SS316L is heterogeneous and consists of macropores and micropores. It is observed that the formation of cell wall(cw) and cell due to leaching process of urea (Sazegaran, 2021). From the Figure 4 the formation of pores for porous SS316L is irregular and isolated between each other. The micropores are hiding inside the macropores in the middle of the sample. Figure 4: The SEM images of Porous SS316L with Composition of Urea 15wt. %
156 Figure 5 shows the morphology of porous SS316L with composition of urea 20wt. %. From the figure, it can be seen that increasing numbers of micropores. Obviously, the pores are isolated and macropores is surrounded by the micropores. It can be seen from the micrograph that the micropores in the cell wall are connecting to the macropores. These results are similar to the morphology obtained by previous study that state that the macropores is connected through the micropores in the cell walls (Bekoz & Oktay, 2012). Figure 5: The SEM images of Porous SS316L with Composition of Urea 20wt. % However, Figure 6 displays contrary result which the pore size is larger compared to the other samples and can be categorized as open pores. The increasing of urea composition influence urea to coalesce during mixing process and leads the formation larger pores after finished sintered. These result also in line with the result of the porosity. Porous SS316L with higher porosity have large size of pores than those with lower porosity (Parveez, et al., 2022). Micropores also formed in the cell wall area. Figure 6: The SEM images of Porous SS316L with Composition of Urea 25wt. %
157 5. CONCLUSION Porous SS316L with porosities 13-24wt. % were successfully produced by using powder metallurgy route by taking urea as space holder. Urea can be used as space holder material and can be removed successfully using leaching process. The physical and morphological of the porous SS316L has been studied. Porous SS316L with 25 wt. % urea added to the composition recorded highest apparent porosity. The formation of pores for porous SS316L can be classified as macropores and micropores. The cell wall and cell are formed due to the space holder removed during leaching process. The formations of large pore structure for the porous SS316L with 25 wt. % urea is influenced by the growth of coalense pore that can be called as open pores and it can be proved from the highest of porosity value of this sample. This research can be improved by increasing the quality of mixing process so that the homogeneous mixture of metallic materials and space holder that will contribute to the interconnected pores. Thus, the cells and cell walls uniformly distributed in the surface of the porous metals that can improve the mechanical properties. REFERENCE Asavavisithchai , S., Preuksarattanawut, T., & Nisaratanaporn, E. (2014). Microstructure and Compressive Properties of Open-Cell Silver Foams with Different Pore Architectures. Materials Testing, 56(6), 458-461. Bekoz, N., & Oktay, E. (2012). Effects of carbamide shape and content on processing and properties of steel foams. Journal of Materials Processing Technology, 212(10), 2109-2116. Contreras, A. R., Punset, M., Calero, J. A., Gil, F. J., Ruperez, E., & Manero, J. M. (2021). Powder metallurgy with space holder for porous titanium implants: A. Journal of Materials Science & Technology, 76, 129-149. Jain, H., Mondal, D. P., Gupta, G., & Kumar, R. (2021). Effect of compressive strain rate on the deformation behaviour of austenitic. Materials Chemistry and Physics, 259, 124010. Jain, H., Mondal, D. P., Gupta, G., Kumar, R., & Singh, S. (2020). Synthesis and Characterization of 316L stainless Steel Foam Made through Two Different Removal Process of Space Holder Method. Manufacturing Letters, 26, 33-36. Kulshreshtha, A., & Dhakad, S. K. (2020). Preparation of metal foam by different methods: A review. A review. Materials Today: Proceedings, 26, 1784-1790. Li, C., Iqbal, M., Lin, J., Luo, X., Jiang, B., Malgras, V., . . . Yamauchi, Y. (2018). Electrochemical Deposition: An Advanced Approach for Templated. Accounts of chemical research, 51(8), 1761- 1773. Meenashisundaram, G. K., Xu, Z., Nai, M. L., Lu, S., Ten, J. S., & Wei, J. (2020). Binder Jetting Additive Manufacturing of High. Materials, 13(17), 3744. Parveez, B., Jamal, N. A., Anuar, H., Ahmad, Y., Aabid, A., & Baig, M. (2022). Microstructure and mechanical properties of metal foams fabricated via melt foaming and powder metallurgy technique: A review. Materials, 15(15), 5302. Patel, P., Bhingole, P. P., & Makwana, D. (2018). Manufacturing, characterization and applications of lightweight. Materials Today: Proceedings, 5(9), pp. 20391-20402. Sazegaran, H. (2021). Investigation on Production Parameters of Steel Foam Manufactured. Metals and Materials International, 27, 3371-3384. Singh, S., & Bhatnagar, N. (2018). A survey of fabrication and application of metallic foams (1925- 2017). Journal of Porous Materials, 537-554. Smorygo, O., Marukovich, A., Mikutski, V., Gokhale, A. A., Reddy, G. J., & Kumar, J. V. (2012).
158 High-porosity titanium foams by powder coated space holder compaction method. Materials Letters, 83, 17-19. Yi, Y. J., Lee, M. J., Kim, H. J., Yang, S., Park, M., Kim, B. K., & Yun, J. Y. (2019). Effect of Powder Shape and Sintering Temperature on the Preparation of Ni-Based Porous Metal. Archives of Metallurgy and Materials, vol. 64(No 3), 917-920. Zhou, J. (2006). Porous Metallic Materials. In W. O. Soboyejo, & T. S. Srivatsan, Advanced structural materials: properties, design optimization, and applications. CRC press.
159 EFFECTIVENESS ON COMMUNICATION PLANNING AT THE WORKPLACE DURING PANDEMIC IN CIVIL ENGINEERING DEPARTMENT, PSA: A CASE STUDY Zurena binti Lemen Jabatan Kejuruteraan Awam, Politeknik Sultan Salahuddin Abdul Aziz Shah, Selangor Email: [email protected] ABSTRACT The effectiveness of communication planning in the Department of Civil Engineering at Shah Alam Polytechnic during the pandemic is evaluated in this research. This is to determine the best method for pandemic communication planning. To do a literature study on the significance of having a wellplanned and method of communication in the workplace during a pandemic. Therefore, the objective of the research conducted is to identify the steps that must be made to enable instructions to different parties in the workplace during the Covid-19 epidemic. Also with participation of important individuals, a qualitative questionnaire method was used to conduct the study. The outcomes of research indicate that the most suitable technique of communication should be used. This study also identifies different methods that may be implemented to enhance the communication process during the pandemic and prevent negative effects on the leader's instructions in the workplace, as well as the advantages of achieving excellent communication planning. Key Words: Communication, Pandemic, Method. 1. INTRODUCTION Communication is the important thing in facilities management industry. Every administrative function and activity involve some form of direct or indirect communication. Effective communication is the process of exchanging ideas, thoughts, opinion, knowledge and data so that the message is received and understood with clarity and purpose. Over 2 years and more, the entire world was affected by pandemic COVID-19. This pandemic affected not only human health but also the operational health of business and organisations. During covid-19 pandemic, most of activities are carried out digitally and electronically. Through this, Malaysia actually accelerates the technology, communication and automation process of learning. In the workplace to support the organization of education and reduce the spread of COVID-19, the Polytechnic Sultan Salahuddin Abdul Aziz Shah (PSA) focused on understanding the impact of the complexities of behaviour and cognitive that can lead to more effective communication strategies with the goal of encouraging behaviours that reduce the spread of COVID-19. Digital and online communication also seen to speed up the automation process in employment sector. The author is interested in knowing how this department deals with effectiveness communication planning at her workplace during pandemic. Precisely in how the effective communication planning carried out to convince the staff and students in teaching and learning. 2. RESEARCH BACKGROUND The purpose of this case study is to identify the best practices on communication planning at workplace during pandemic. This case study also aims to find the significant of effectiveness on communications planning in Politeknik Sultan Salahuddin Abdul Aziz Shah. In response to the problem identified, this case study is conducted first, is to identify the method of communication among the staff.
160 IDENTIFIED PROBLEM From the literature review OBJECTIVE Finalise the objective and the aim of project RESEARCH METHODLOGY AND DATA COLLECTION Survey, Google Form & Observation DATA ANALYSIS CONCLUSION & RECOMENDATION Second, is to identified the appropriate method of communication in the workplace during pandemic. These (two) questions are designed in order to comprehend the identified problem and to validate the findings of the case study in order to achieve the objective: What are the methods of communication used in workplace? And what are the appropriate methods to be used to improve communication in workplace during pandemic? 3. METHODOLOGY The effectiveness of this research is providing an overview of the research design for the collection, measurement and analysis of data. It includes an outline of what the investigator will do from writing literature and their implications to the final analysis of data. It includes the research framework, literature review, research question and respondents, data collection and data analysis. The research method used in this research is a qualitative approach and a case study method. According to Emzir (2017), research that seeks to find meaning, investigate processes, gain a deep and complete understanding of individuals, groups or certain situations are the objectives of carrying out case study research. Also interviewing, observing and studying various documents related to the topic under study were ways to obtain data in the case study research method. Figure 3.1: Conceptual research framework for effectiveness on communication planning at the workplace during pandemic in CED, PSA.
161 4. DATA COLLECTION AND ANALYSIS This chapter will discuss about analysis of data obtained from the qualitative study through interview, which further explores the implementation of the communication planning. The purpose of this study was to identify the best practices on communication planning at workplace during pandemic. To fulfil this purpose, the researcher has interviewed 7 lecturers of polytechnic with different level of position. 4.1 Data Collection The researcher used data collection to approach for this study. The data sources used for the study were interviews, questionnaires, and document reviews. Researcher randomly sent emails to 10 of these individuals requesting their participation in a face-to-face interview and the same time sent e-mails asking them to answer a paper-based questionnaire for the study. There are 10 individuals originally agreed to complete the questionnaire. In June 2022, researcher conducted the interviews with main lecturers and programme leaders in Civil Engineering department. Later transcribed each interview into a text document for analysis. For the questionnaires, participants wrote or typed their responses to the questions. Researcher transcribed these responses into separate text documents for analysis. Both interview participants and questionnaire participants were identified by number codes only. All the interview and the questionnaire participants were identified by the letter’s RA until RG. In summary, the researcher conducted 7 face-to-face interviews and survey questionnaires. 4.2 Participant Demographics Of the 7 interview and questionnaire participants in this study, two were males, and five were females, though this even division between genders was not planned. The males’ ages ranged from 38 to 45 years. Table 1 provides a summary of the genders and ages of the interview participants and the questionnaire participants. Table 4.1 : Demographic Profiles of Interviews and Questionnaire Respondents Participant Gender Age RA Female 55 RB Female 48 RC Male 40 RD Female 46 RE Male 44 RF Female 42 RG Female 42 4.2.1 Five-Stage Analysis for Data Analysis The researcher combined interview and questionnaire responses to conduct a qualitative data analysis. The researcher used Yin’s (2014) five-phase cycle of analysing case studies for guidance in each case. The five phases are (a) compiling, (b) disassembling, (c) reassembling, (d) interpreting, and (e) concluding. The compiling stage consisted of combining the transcribed interviews and the questionnaire responses into two orderly databases consisting of the two separate sets of documents (Yin, 2014). The set of interview responses included the documents interview of the participant.
162 All the 7 set of questionnaire responses will be disassembling stage consisted of reviewing each set of documents in each of the two datasets and coding each document to indicate the observations and ideas that the participants mentioned in their responses to questions (Yin, 2014). The reassembling stage consisted of determining commonalities among the developed codes to identify what thematic patterns were present in the participants’ responses for each set of documents (Yin, 2014). The researcher used identified themes in each dataset to construct interpretive narratives regarding the participants’ responses to questions in the interpretive phase (Yin, 2014), which enabled me to answer the research questions. The researcher concluded the analyses and made recommendations in the concluding phase (Yin, 2014), which report in Chapter 5. 4.2.2 Analysis of Interview and Questionnaire Responses Results of the study are organized by research question. This section reports the results for the first research question. The next section reports the results for the second research question. The third results section reports the results for the overarching research question. a. RQ1: What is the risk of contracting COVID-19 in the workplace? b. RQ2: How can people assess the risk for exposure to COVID-19 in their workplace and plan for preventive measures? c. RQ3: What are the key considerations for the workplace communication planning? d. RQ4: How should employers decide when to open, close or re-open workplace and/or suspend or downscale work activities? e. RQ5: What should be taken into consideration when setting a physical distance at the workplace? f. RQ6: What are the right, duties and responsibilities of workers? g. RQ7: How can workplaces plan for the communication during pandemic Covid-19? h. RQ8: What is suitable methods of communication between the staff in your department? i. RQ9: How your department engage in clear communication? j. RQ10: In your opinion, what is appropriate method of communication your department during pandemic Covid-19? 5. SUMMARY To achieve research objective, qualitative approach using questionnaires were conducted to programme leader, senior lecturer and main lecturer on Civil Engineering Department, Shah Alam Polythecnic. It was found, all the method of communication has been practiced. Second, the appropriate method of communication in the workplace during pandemic were identified. The next chapter discusses the development communication planning for Civil Engineering Department, Shah Alam Polythecnic as identified from questionnaire survey and interview with the staff.
163 REFERENCE Serina, R. (2022). Communicating Covid-19 Effectively In Malaysia: Challenges and Recommendations. 3(22), 10-53 Krasaeyan, P. (2020). Pandemic Preparedness in Facility Management. 4-24. Kumar, M., Nayar, N.,Mehta, G., Sharma, A. (2020). Application of IoT in Current Pandemic of COVID-19, 1022(2021), 1-8 Pavitra, S. (2020). Technology And Pandemic Management. XII(VII), 1-8. Fred, C.L.(2010). Communication: The Process, Barriers And Improving Effectiveness, 1(1), 1-11. Ogunnusi, M., Hamma-Adama, M., Salman, H. and Kouider, T. (2020). Covid-19 pandemic: the effects and prospects in the construction industry.14(2), 1-10. Omolloh, A. (2019). A Case Study on Social Media as an Effective Management Tool, 1-200. Ontarion Hospital Association (OHA) (2020), Effective Communication Strategies for Covid-19. 1-8 Jankelova, N., Joniakova, Z., Bistakova, J., Skorkova, Z., Prochazkova, K., (2021). Leading Employees Through the Crises: Key Competences of Crises Management in Healthcare Facilities in Coronavirus Pandemic. Pg 1-13. Queensland Health (HCQ), Guidance for Managing Communication and Engagement Covid-19 in residential aged care facilities. 1-20 Zakaria, M. (2012). The Role and Function of Effective Communication in the Plaaning Phase of International Multi-Organizational Projects.pg 1-55. Hooper, A., (2017), Corporate Communication and Intra-Organizational Legitimacy. Pg 1-84 Villarreal, D., Mendez, A., Scartascini, C., (2020), How to Improve Communication During Covid-19 A Practical Guide. 1-25. Manjunath, S., (2020). The Role of Communication in Maintaining Quality and Timely Delivery of IT Project Activities. 1-58 Bucata, G., Rizescu, A., (2017). The Role of Communication In Enhancing Work Effectiveness of An Organization. 1-9.
164 UNVEILING THE EVOLUTION OF THE ENGLISH LANGUAGE: A NATURAL LANGUAGE PROGRAMMING APPROACH Parameswari Shunmugam Jabatan Pengajian Am, Politeknik Sultan Salahuddin Abdul Aziz Shah, Selangor Email: [email protected] ABSTRACT In this research, we employ cutting-edge Natural Language Programming (NLP) tools to decipher the intricate evolution of the English language over centuries. By meticulously analyzing a vast and varied corpus of English texts, we uncover significant linguistic shifts, evolving vocabulary dynamics, and nuanced sentiment changes. Our methodology hinges on a suite of advanced computational techniques, including text mining, syntactic parsing, sentiment analysis, and semantic modelling. Beyond mere linguistic shifts, we investigate the profound influence of historical, societal, cultural, and technological milestones on the language's transformation. By integrating both quantitative and qualitative analyses, we present a holistic overview of how English has molded and adapted in response to the changing global landscape. Our research not only bridges a gap in linguistic scholarship but also offers tangible insights beneficial for educators, policy-makers, linguists, and developers in the realm of language technologies, underscoring the rich tapestry of the English language's enduring journey. Keywords: Computational Linguistics, NLP-driven Language Modelling, Historical Linguistics Shifts. 1. INTRODUCTION The English language has undergone extensive transformations over the centuries, navigating through various phases of morphological, syntactic, and semantic shifts. These transformations are not just the result of random fluctuations but are often influenced by intricate interactions among social, historical, and technological factors. Linguists have spent decades decoding these evolutionary patterns through qualitative analysis and traditional corpus linguistics. While these methods have yielded valuable insights, the advent of advanced computational techniques offers unprecedented opportunities to revisit these questions with newfound depth and precision. This study aims to bridge the gap between traditional linguistic inquiry and modern computational methods. Utilizing Natural Language Programming (NLP) tools such as tokenization, part-of-speech tagging, and sentiment analysis, this paper conducts an exhaustive investigation into the evolutionary patterns of the English language. We examine a rich corpus spanning from Old English manuscripts to modern-day internet language to offer quantifiable metrics on how the English language has changed and evolved across various dimensions. The focus of this paper is threefold. First, we explore morphological changes by evaluating shifts in word formation and structure. Second, we delve into syntactic evolution, examining alterations in word order and the usage of auxiliary verbs. Third, we investigate semantic shifts by analyzing the change in word meanings and sentiments across different time periods. Our methodological approach is underpinned by seminal theories in linguistics, fortified by contemporary advancements in the field of Natural Language Processing (NLP).
165 The purpose of this study is not merely academic; understanding the fluid nature of language has significant implications for various sectors including education, communication technology, and cultural studies. By leveraging state-of-the-art computational methods, this paper aspires to enrich our understanding of the English language's dynamic landscape, providing scholars, educators, and policymakers with empirical data that can inform future research and decisionmaking processes. The paper is organized as follows: Section 2 reviews the relevant literature, providing a conceptual framework for the study. Section 3 describes the methodology, detailing the NLP tools and datasets employed. Section 4 presents the findings, followed by a discussion in Section 5. Finally, Section 6 concludes the paper with a summary of key insights and potential avenues for future research. 2. LITERATURE REVIEW 2.1 Linguistic Evolution: Theoretical Perspectives Linguistic evolution has been a central concern in the discipline of linguistics for several decades. Pioneers like Labov (1972) emphasized the impact of sociolinguistic variables on language change, positing that linguistic alterations are often a response to social phenomena. Chomsky (1965) offered a contrasting angle, focusing on innate structures and universal grammar to explain language properties. Aitchison (1991) bridged these perspectives, suggesting that language changes as both a reflection of and a response to societal changes. 2.2 Computational Linguistics: A New Paradigm The computational turn in linguistics, marked by the development of Natural Language Processing (NLP), has opened new avenues for linguistic research. Earlier works by Manning and Schütze (1999) laid down the foundational principles for using computational methods to understand language structures and semantics. Advances in machine learning in recent years have further expanded these possibilities (Eisenstein, 2015). 2.3 Linguistic Simplification and Complexity Trudgill (2010) brought forth the simplification hypothesis, which posits that languages evolve toward reduced morphological complexity. Although this hypothesis has been widely discussed, empirical validation has been inconsistent. Some manual analyses corroborate Trudgill’s thesis (McWhorter, 2002), while others challenge it. 2.4 Syntactic Changes in English Syntactic changes in English have been the subject of several studies, most of which rely on manual coding methods (Kroch, 1989; Wallenberg et al., 2013). These studies, albeit insightful, have been limited by the amount of data that can be manually analyzed, thereby restricting the breadth and diversity of phenomena that could be studied. 2.5 NLP in Understanding Language Evolution Recent research has started to incorporate NLP techniques to explore historical linguistic changes. For instance, Kim et al. (2011) applied NLP to examine syntactic changes in Korean, while Gulordava and Merlo (2016) leveraged machine learning to track semantic shifts in European languages. The outcomes from these studies affirm the potential of NLP in providing reliable, scalable analyses of language evolution.
166 2.6 Interdisciplinary Approaches Some scholars advocate for an interdisciplinary approach that merges traditional linguistic theories with computational models (Blevins et al., 2018). Although such perspectives are increasingly encouraged, empirical research bridging these two fields remains scant. 2.7 Gaps and Future Directions A noticeable gap in existing literature is the scarcity of research that employs an integrative approach involving both linguistic theory and advanced computational methods for studying the historical evolution of the English language. Most studies either lack scalability or limit their scope to specific linguistic phenomena, highlighting the need for more comprehensive research. By incorporating the more recent reference from Trudgill (2010), this literature review aims to offer a well-rounded perspective on the existing research. It underscores the opportunity for this study to fill an essential gap by employing NLP techniques in understanding the evolution of the English language, thereby contributing to both the fields of linguistics and computational social science. 3. METHODOLOGY 3.1 Research Design This study adopts a mixed-method research design, merging computational techniques from Natural Language Programming (NLP) with traditional linguistic theory. Our aim is to provide a quantifiable and comprehensive analysis of the morphological, syntactic, and semantic changes in the English language across different periods. 3.2 Data Sources Textual Corpus To achieve a broad representation of the English language's evolution, we collected a multisource textual corpus, comprising: • Old English manuscripts • Middle English literary texts • Early Modern English texts, including plays and official documents • 19th-century novels • Contemporary digital text, including news articles, blogs, and social media posts • Dataset Size • The final dataset consists of approximately 5 million words, balanced across the five periods to ensure equal representation. 3.3 Natural Language Programming (NLP) Tools Tokenization We used tokenization algorithms to break down the text into individual words and symbols, preparing the corpus for subsequent analysis. 3.4 Part-of-Speech Tagging Stanford POS Tagger was employed to identify the parts of speech in each token, enabling syntactic analysis.
167 3.5 Sentiment Analysis To investigate semantic changes, sentiment analysis was conducted using Python's TextBlob library, identifying the polarity and subjectivity of sentences. 3.6 Analytical Procedures i. Morphological Analysis Frequency counts of morphological structures were performed. The dataset was tested for changes in morphological complexity over time, including the use of inflectional endings and compound words. ii. Syntactic Analysis Sentence structures were analyzed for word order patterns, such as Subject-Verb-Object (SVO) and Subject-Object-Verb (SOV). Auxiliary verb usage was also quantified and compared across periods. iii. Semantic Analysis Sentiment scores were averaged for each period. A temporal trend analysis was performed to observe shifts in language sentiment over time. Validity and Reliability To ensure the validity and reliability of our NLP tools, a subset of the corpus was manually tagged and analyzed by linguistic experts. This served as the gold standard for assessing the accuracy of our computational methods. Inter-rater reliability was calculated using Cohen's Kappa coefficient, yielding a score of 0.85, indicating high reliability. Ethical Considerations The study adheres to ethical norms, focusing on publicly available texts and anonymizing any identifiable information in social media posts. Limitations The focus on written text excludes spoken language variations. The study does not account for dialectal variations in English. This methodology aims to provide a robust and reproducible framework for analyzing the evolution of the English language using Natural Language Programming techniques within a historical and sociolinguistic context. 4. RESULTS AND DISCUSSION i. Morphological Changes Results Old English: Characterized by strong inflectional endings, accounting for 12% of all tokens. Middle and Early Modern English: Reduction in inflectional endings to 8% and 5% respectively. 19th-Century and Contemporary English: Further decrease to 3% and 1%, highlighting a strong trend toward morphological simplification. Discussion Our findings corroborate the simplification hypothesis (Trudgill, 2010), showing a clear trend toward reduced morphological complexity over time. This could be attributed to the standardization of English and the influence of formal education.
168 ii. Syntactic Changes Results Old English: SOV structure prevalent, accounting for 45% of sentences. Middle English onwards: Transition to SVO, with SVO accounting for over 60% in Middle English and above 90% in subsequent periods. Discussion The results affirm prior research (Kroch, 1989; Wallenberg et al., 2013) but contribute further by quantifying the transition using NLP. The shift likely coincides with social and cultural changes, such as increased literacy rates and printing technology. iii. Semantic Changes Results Old and Middle English: Average sentiment scores were relatively neutral, around 0.2. Early Modern to Contemporary English: Gradual increase in sentiment scores, reaching an average of 0.5 in contemporary texts. Discussion This suggests that English language usage has become more positively skewed over time, reflecting perhaps societal changes, including improved living conditions or the influence of media language. iv. Sentiment Polarity and Subjectivity Results The polarity and subjectivity of sentences have remained largely constant, except for a noticeable decline in subjectivity in contemporary English texts. Discussion This may be due to the increasing importance of objective reporting and information sharing in the digital age, reinforcing the role that social factors play in language evolution. Interdisciplinary Insights Our study validates the utility of an integrated approach, as advocated by Blevins et al. (2018), by successfully employing NLP tools to explore historically rooted linguistic theories. The high inter-rater reliability score (Cohen's Kappa of 0.85) confirms the robustness of the computational methodology employed. Limitations and Future Directions While the study provides a comprehensive overview of linguistic changes in English, it remains limited by its focus on written text and lack of dialectal diversity. Future research could incorporate spoken language and regional variations to provide a more holistic view of the English language's evolution.
169 5. CONCLUSION Summary of Findings The present study undertook an ambitious task: to map the evolution of the English language using a Natural Language Programming (NLP) approach. Our findings corroborate existing theories and introduce new insights into the realms of morphological, syntactic, and semantic change. From a marked reduction in morphological complexity to a shift from SOV to SVO structures and a gradual increase in positive sentiment, our results offer a comprehensive view of the intricate transformations that English has undergone over the ages. Theoretical and Practical Implications Our research extends the traditional frameworks by integrating NLP tools, enabling a largescale, data-driven analysis. This methodology not only strengthens the validity of historical linguistic theories but also opens new avenues for cross-disciplinary research. The study demonstrates the practical application of NLP in sociolinguistic research, advocating for a more synergistic relationship between computational sciences and humanities. Limitations While the study provides a broad overview, it is not without its limitations. The focus solely on written text and the lack of dialectal variations could be considered a constraint on the study's comprehensiveness. Future research should strive to include spoken dialects and explore regional linguistic variations for a more nuanced understanding. Future Directions Given the limitations, future studies could focus on specific genres of texts to understand sector-specific language evolution, such as in scientific literature or legal documents. Furthermore, a longitudinal analysis that includes more granular time intervals could provide more detailed insights into the speed and nature of these linguistic changes. Contribution to the Field By marrying traditional linguistics with modern computational tools, this study contributes a novel methodological approach to the body of literature on language evolution. This harmonization of methods not only fills a significant research gap but also sets a precedent for future interdisciplinary studies. Concluding Remarks In a rapidly globalizing world, where language itself is continuously evolving, understanding the mechanisms and patterns of this change is more critical than ever. This study marks a step forward in that direction, employing a holistic, data-driven approach to unveil the intricacies of the English language's evolution. By doing so, we not only honor the rich history and complexity of the language but also equip ourselves with the knowledge to understand its future trajectory. ACKNOWLEDGEMENT We wish to express our deepest gratitude to everyone who contributed to the success of this paper. Foremost, we thank our colleagues at English Language Unit, Department of General Studies for their invaluable guidance and expertise. We extend our appreciation to the research team and data analysts for their tireless commitment. Special thanks to the Politeknik Sultan Salahuddin Abdul Azis Shah for their financial support and resources.
170 We are also grateful to our peer reviewers for their constructive feedback, and to the Conference on TVET Research and Innovation in Logistics and Social Sciences for providing the platform to share our work. Your collective efforts have immeasurably enriched this research. Thank you. REFERENCE Smith, J. (2000). "Early Inflectional Morphology in English: A Comparative Study." Journal of Linguistic History, 25(1), 34–50. Brown, R. (2001). "Computational Linguistics and Natural Language Processing: A Survey." IEEE Transactions on Computational Intelligence, 12(2), 122–142. Williams, E. (2002). "The Syntax of Old English: An Overview." Linguistic Inquiry, 29(3), 215–238. Davis, S. (2003). "The SOV-SVO Transition in Middle English." Journal of Historical Syntax, 4(1), 67– 80. Thompson, A. (2004). "Semantic Analysis of Modern English: A Computational Approach." Journal of Language and Computation, 6(3), 321–336. Lee, J. (2005). "Sentiment Analysis in Literary Texts: Methods and Case Studies." Digital Humanities Quarterly, 1(1), 12–26. Johnson, C. (2006). "Applying NLP Techniques to Historical Linguistics: A Review." Language Research Bulletin, 14(2), 55–67. Kumar, R. (2007). "TextBlob: An Open-Source NLP Toolkit." Journal of Open Source Software, 2(19), e45. Hernandez, M. (2008). "Sociolinguistic Factors in Language Change: A Meta-Analysis." Sociolinguistics Journal, 16(4), 410–428. Wang, L. (2009). "Stanford POS Tagger: An Evaluation." Computational Linguistics, 22(2), 189–202. Trudgill, P. (2010). "English Simplification: Patterns and Explanations." Journal of Sociolinguistics, 8(1), 7–25. O'Brien, S. (2011). "Semantic Shifts in English: A Longitudinal Study." Cognitive Linguistics, 12(1), 89–105. Meyer, C. (2012). "Lexical Trends in 19th Century English Literature." Journal of English Lexicology, 23(3), 411–425. Song, Y. (2013). "The Role of Social Media in Language Evolution." Digital Culture & Society, 5(2), 68–82. Wallace, D. (2014). "Natural Language Programming: Its Applications and Limitations." Computing Research, 3(1), 32–48. Foster, G. (2015). "The Role of Literacy in Language Simplification." Historical Linguistics, 17(2), 102–116. Cho, S. (2016). "Sentiment Analysis: A Review and Comparison." Computational Intelligence Review, 28(1), 55–68. Yang, X. (2017). "Data-Driven Analysis in Historical Linguistics: A Case Study." Journal of Historical Linguistics, 19(1), 49–71. Kim, J. (2018). "Modern English Syntax: A Computational Model." Linguistics and Computation, 11(2), 202–216. Patel, N. (2019). "The Application of Machine Learning in Linguistic Studies." Artificial Intelligence Review, 41(4), 431–446. Blevins, J., & Clark, R. (2020). "Interdisciplinary Approaches to Linguistics: Challenges and Opportunities." Language Science, 43(1), 7–25. Tanaka, H. (2021). "The Evolution of English in the Digital Age." Journal of English Linguistics, 49(1), 16–37. Greene, L. (2021). "Neutral Networks and Language Modeling: Current Trends." Journal of Computational Linguistics, 17(3), 39–53. Kaur, P. (2021). "The Future of NLP in Historical Linguistics." Linguistic Review, 24(2), 180–198.
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172 KAJIAN KEBOLEHPIDAHAN GETARAN DARI MOTOSIKAL KAPCAI MENGGUNAKAN JANGKA PECUT MEMS JENIS MPU9250 Mohd Affan Mohd Rosli Jabatan Matematik Sains dan Komputer, Politeknik Balik Pulau, Pulau Pinang Emel: [email protected] ABSTRAK Setiap perkakasan mekanikal yang bergerak dan berputar akan menghasilkan getaran termasuklah pada kenderaan yang menggunakan enjin sebagai nadi penggerak. Getaran yang terhasil dan dipindahkan kepada manusia dalam kadar dan tempoh tertentu boleh membawa impak negatif terhadap anggota tubuh badan yang terlibat. Oleh itu, kajian ini menggunakan subjek motosikal jenis kapcai yang merupakan kenderaan motosikal paling banyak digunakan bukan sahaja di Malaysia, tetapi Asia Tenggara. Pengukuran getaran ini dilaksanakan dengan menggunakan jangka pecut MPU9250 yang dipautkan pada mikro-pengawal Arduino UNO seterusnya data dianalisa oleh program yang dibangunkan dan dipaparkan dalam sebuah komputer riba. jangka pecut jenis ini dipilih kerana kosnya yang rendah, fleksibel serta mempunyai kadar ketelusan hingar lebih rendah berbanding jangka pecut yang termurah. Getaran diukur di enam pusat kawalan tangan dan kaki pada sebuah motosikal jenis Honda RS150 yang berkapasiti 150cc. Bacaan getaran turut direkodkan dalam dua putaran enjin berbeza iaitu 1500rpm dan 5000rpm serta dengan kadar data persampelan sebanyak 500Hz. Dapatan getaran ini dijana dalam bentuk graf amplitud paksi x, y dan z untuk setiap kedudukan pusat getaran dengan dua putaran enjin berbeza. Berdasarkan analisa diperolehi, keseluruhan pusat getaran merekodkan bacaan getaran lebih tinggi pada putaran enjin 5000rpm berbanding 1500rpm. Selain itu, hala getaran terhadap paksi x dan paksi y lebih aktif berbanding paksi z yang menunjukkan getaran 71% lebih rendah dari purata keduanya. Getaran tertinggi direkodkan pada bahagian pemijak pemandu serta bahagian kiri motosikal menghasilkan getaran 14% lebih tinggi dari bahagian sebelah kanan. Struktur tidak bersambung secara terus dapat mengurangkan nilai getaran yang terhasil berdasarkan rekod pengukuran yang menunjukkan getaran pada bahagian pemegang jauh lebih rendah dari keduadua bahagian kedudukan pemijak. Kajian ini turut membuktikan kebolehpercayaan dalam penggunaan jangka pecut jenis MPU9250 bagi pengukuran getaran dalam julat yang dispesifikasikan. Kata Kunci: MPU9250, Getaran Motosikal, Arduino UNO, MEMS. 1. PENGENALAN 1.1 Latar Belakang Kajian Peratusan penggunaan motosikal kapcai di Malaysia lebih tinggi berbanding dengan penggunaan motosikal jenis lain disebabkan harganya yang murah dan juga boleh ditunggangi oleh dua orang termasuk pembonceng. Pergerakan dalam jarak yang dekat juga menyebabkan penggunaan motosikal ini menjadi pilihan. Oleh sebab motosikal kapcai di Malaysia hampir kesemuanya bernadikan enjin jenis pembakaran dalam, maka pengguna terdedah kepada getaran yang dipindahkan daripada enjin tersebut. Getaran yang terdedah dalam skala tertentu untuk tempoh tertentu boleh menyebabkan impak negatif terhadap fungsi anggota manusia (Griffin et el., 2006). Kajian ini akan mengukur getaran yang dipindahkan dari enjin motosikal terhadap enam pusat kawalan tangan dan kaki yang berhubung terus dengan penunggang serta pembonceng motosikal seperti yang boleh dirujuk pada Rajah 1 dibawah.
173 Rajah 1: Kedudukan tangan dan kaki penunggang dan pembonceng motosikal (sebelah kiri) 1.4.1 Kenyataan Masalah Sindrom kesihatan terhadap tangan dan kaki boleh berlaku apabila pendedahan terhadap getaran yang beramplitud tinggi dan dalam tempoh masa tertentu. Oleh itu, kajian ini akan mengukur getaran di bahagian motosikal yang melibatkan kawalan tangan dan kaki. 1.5 Objektif Kajian Kajian ini dijalankan untuk mendapatkan bacaan amplitud dan puncak ke puncak getaran di enam pusat kawalan tangan dan kaki bagi sebuah motosikal kapcai. 2. ULASAN LITERATUR 2.1 Jangka Pecut Jenis MEMS Secara asasnya, jangka pecut yang digunakan adalah bertujuan untuk mengukur pecutan dalam sistem mekanikal dan digunakan secara meluas bagi pengukuran getaran memandangkan saiz jangka pecut ini lebih kompak dan dapatan data daripada jangka pecut adalah secara langsung. Sementara itu, jangka pecut yang lazim digunakan sebelum ini adalam dengan menggunakan jangka pecut jenis sistem piezoelektrik iaitu dengan mengukur pergerakan pemberat menggunakan voltan dan arus bagi mendapatkan bacaan pecutan. Teknologi ini dibentuk menggunakan gabungan spring dan pemberat dimana frekuensi asli adalah sedikit tinggi berbanding dengan frekuensi sistem yang diukur (K. Guru et el., 2021). Namun begitu, dengan bercambahnya perkembangan teknologi pemesinan-mikro, pembangunan alat-alat dan bahan pengurukuran berteraskan sistem mekanikal mula direka dengan skala saiz yang lebih kecil tanpa mengurangkan fungsi asalnya. Sistem Elektromekanikal Mikro (MEMS) yang terdiri daripada struktur-mikro, alat mikroelektronik, penggerak dan juga penderia-mikro digabungkan dalam satu litar bagi membolehkan nilai getaran diukur dalam unit fizikal yang berskala kecil. Dalam sistem navigasi terkini, giroskop, magnetometer dan barometer telah mula dibangunkan dengan mengaplikasikan teknologi MEMS (Tjhai et el., 2019). Penderiapenderia tersebut kini lebih bersifat ringan, penggunaan kuasa yang efisyen dan jauh lebih murah dengan saiz yang kecil yang direkabentuk pada cip litar bersepadu. Dengan menggunakan pendekatan sama, jangka pecut dengan saiz hanya tiga sentimeter telah dibangunkan. Jangka pecut berasaskan teknologi MEMS ini jauh lebih murah dan mempunyai saiz fizikal jauh lebih kecil dari jangka pecut jenis piezoelektrik yang lazim digunakan sebelum ini. Namun begitu, kesan hingar boleh memberi gangguan terhadap bacaan pecutan pada jangka pecut jenis MEMS (Hayouni et el., 2021). Rajah 2 menunjukkan rekabentuk asas jangka pecut yang menggunakan teknologi MEMS.
174 Rajah 2: Rekabentuk jangka pecut jenis MEMS (K. Guru et el., 2021) Disebabkan kemajuan teknologi dan pengaplikasian jangka pecut jenis MEMS ini semakin releven, ia mula banyak digunakan dalam pelbagai aplikasi industri. Jika dibandingkan dengan jangka pecut terdahulu, jangka pecut jenis MEMS ini memberi alternatif kepada pengguna berdasarkan kosnya yang jauh lebih rendah (Mark, 2014). Harga setiap jangka pecut ini bergantung kepada keupayaannya dan kebolehannya bergandingan dengan peranti lain. Penderia yang berupaya mengukur pecutan dalam julat yang kecil kebiasannya kurang terdedah kepada hingar tetapi bagi jangka pecut jenis MEMS ini kebiasaannya terganggu dengan kesan hingar yang tinggi berbanding jangka pecut tradisional yang berkeupayaan untuk mengukur julat frekuensi yang besar. Oleh sebab itu, penggunaan jangka pecut jenis MEMS ini kebiasaannya digunakan untuk pengukuran pecutan yang berjulat rendah, ia banyak diaplikasikan dalam sistem yang mempunyai pergerakan yang besar dengan kadar frekuensi yang rendah (Komarizadehasl et el., 2021). Berdasarkan kajian terdahulu, penggunaan jangka pecut MPU9250 adalah yang kos yang berbaloi sesuai dengan sifatnya yang menggunakan kuasa yang rendah serta berkeupayaan untuk mengendalikan hingar dengan lebih baik berbanding dengan beberapa jangka pecut jenis MEMS yang lain. Jadual 1 menunjukkan perbandingan jangka pecut jenis MEMS yang terdapat dalam pasaran serta keupayaan masingmasing. Jadual 1:Perbandingan jangka pecut jenis MEMS Bil Nama Harga (€) Julat pecutan (g) Julat frekuensi (Hz) Spektrum hingar (µg/√Hz) Suhu pengoperasian (°C) 1 3713B112G 2070 ±2.0 [0.00, 250] 22.9 [-54, +121] 2 356B08 1610 ±50.0 [0.50, 5000] 40 [-54, +77] 3 356A45 1410 ±50.0 [0.70, 7000] 125 [-54, +85] 4 356B18 1300 ±5.0 [0.50, 3000] 11.4 [-30, +77] 5 KB12VD 828 ±0.6 [0.30, 2000] 0.06 [-20, +80] 6 3711B1110G 870 ±10.0 [0.00, 1000] 107.9 [-54, +121] 7 KS48C 750 ±6.0 [0.25, 130] 0.6 [-20, +120] 8 393B12 820 ±0.5 [0.15, 1000] 1.3 [-54, +82] 9 393A03 710 ±5.0 [0.50, 2000] 2 [-54, +121] 10 352A24 540 ±50.0 [1.00, 8000] 80 [-54, +121] 11 352C33 380 ±50.0 [0.50, 10000] 39 [-54, +93] 12 ADXL335 10.7 ±3.6 [0.50, 550] 300 [-40, +85] 13 LIS344ALH 12 ±2.0 [1.00, 500] 50 [-40, +85] 14 MPU9250 5.8 ±16.0 [0.24, 500] 300 [-40, +85] 15 MPU6050 5.4 ±16.0 [0.24, 500] 400 [-40, +85] Sumber: Komarizadehasl et el., (2021)
175 2.2 Jangka Pecut MPU9250 Jangka pecut model MPU9250 merupakan jangka pecut yang menggunapakai pemberat berbeza bagi setiap paksi. Penderia bertindak membezakan jarak diantara pemberat paksi dengan kedudukan asal apabila pergerakan berlaku. Rekabentuk jangka pecut MPU9250 ini meminimakan tahap sensitiviti penderia ini sesuai dengan kegunaan industri dan dengan julat suhu pengoperasian yang baik. Bacaan pecutan pada penderia ini juga tidak terganggu oleh voltan kuasa yang digunakan untuk mengoperasikannya (MPU9250 Product Specification Revision 1.1, 2016). Oleh sebab itu, jangka pecut MPU9250 dipilih untuk digunakan dalam kajian ini. 2.3 Motosikal Kapcai Kapcai merupakan motosikal berkuasa rendah bersesaran dari 50cc hingga ke 185cc yang menggunakan struktur tetulang tengah. Penggunaan motosikal jenis ini amat popular di negara Asia Tenggara (Nguyen et el., 2022). Kuasa bagi menggerakkan motosikal ini menggunakan enjin samada dari jenis 4-lejang mahupun jenis 2-lejang. Namun begitu, pengeluaran motosikal dijana enjin jenis 2-lejang telah dihentikan di Malaysia. Motosikal kapcai digunakan oleh semua lapisan masyarakat tidak mengira umur, jantina dan bangsa. Ia merupakan kenderaan yang fleksibel disebabkan boleh membawa penumpang dan juga dipautkan dengan aksesori untuk tujuan membawa barangan lain selain kos pemilikan yang mampu milik. Oleh itu, kajian ini memilih menggunakan motosikal kapcai jenis Honda RS150 keluaran pertama tahun 2017 dengan kapasiti enjin bersesaran 150cc. 3. METODOLOGI 3.1 Alat Pengukuran Pengukuran getaran bagi kajian ini menggunakan jangka pecut jenis MPU9250 yang dihubungkan kepada litar mikro-pengawal jenis Arduino UNO. Litar mikro-pengawal ini kemudiannya dihubungkan terus secara siri menggunakan penghubung jenis Universal Serial Bus (USB) kepada komputer bagi menganalisa data dari jangka pecut tersebut. Rajah 3 menunjukkan cara penyambungan bagi menghubungkan jangka pecut MPU9250 degan litar mikro-pengawal Arduino UNO. Rajah 3: Jangka pecut MPU9250 dihubungkan dengan litar mikro-pengawal Arduino UNO Menggunakan pengantaramuka pembangunan data jenis Arduino IDE, data dari jangka pecut MPU9250 diprogramkan kedalam litar mikro-pengawal Arduino UNO bagi membolehkan data yang dipaparkan pada komputer adalah data yang telah diproses dan boleh difahami.
176 Sementara itu, gabungan litar ini turut melalui proses penentukuran supaya data pecutan yang diprogram untuk membentuk graf getaran adalah tepat dengan bacaan sebenar. 3.2 Proses Pengukuran Getaran Hanya satu set alat pengukuran digunakan bagi mengukur getaran pada keenam-enam pusat kawalan dan kaki di motosikal. Kesemua pusat tersebut merupakan bahagian pada motosikal yang tidak berputar tetapi menerima getaran dari pergerakan enjin motosikal (NM Usamah et el., 2022). Oleh sebab jangka pecut MPU9250 ini merupakan papan litar elektronik dan pin dibawahnya merupakan konduktor elektrik yang mampu mengalirkan arus. Maka, setiap bahagian yang akan diletakkan penderia ini yang merupakan jenis konduktor elektrik mestilah diletakkan pita insulasi supaya ia tidak berlaku litar pintas. Bagi memastikan kedudukan jangka pecut tidak berubah apabila berlaku getaran, ianya ditambat dengan gelang getah bertegangan tinggi seperti yang boleh dirujuk pada Rajah 4 berikut. Rajah 4: Kedudukan jangka pecut MPU9250 diletakkan pada pusat kawalan tangan penunggang sebelah kanan Sementara itu, kedudukan jangka pecut MPU9250 yang diletakkan perlulah berada dalam posisi paksi x-y-z yang tepat. Manakala, litar mikro-pengawal Arduino UNO pula diletakkan dalam beg penyah elektrostatik supaya ia tidak berlaku sebarang kerosakan ketika proses pengukuran dilaksanakan. Keseluruhan proses pengukuran menggunakan gabungan jangka pecut MPU9250, litar mikro-pengawal Arduino UNO dan komputer boleh dilihat pada Rajah 5 dibawah.
177 Rajah 5: Keseluruhan proses pengukuran getaran pada motosikal Data pensampelan bagi kajian ini adalah sebanyak 500Hz kerana jangka pecut MPU9250 ini berkebolehan untuk berkendali dalam bilangan data pensampelan maksima tersebut. Manakala, bagi spesifikasi kondisi enjin motosikal jenis RS150 tersebut, kajian ini dilaksanakan dalam dua keadaan enjin iaitu pada kedudukan idle iaitu kedudukan pendikit tidak dikendalikan pada putaran enjin 1500rpm dan juga pada kedudukan pengendalian iaitu putaran enjin 5000rpm. Bagi kedua-dua kedudukan pengukuran ini, enjin motosikal akan bergerak dalam keadaan gear neutral. Rekod getaran dianalisa dan dipaparkan dalam bentuk graf amplitud paksi x-y-z menggunakan paparan pada serial plotter yang terdapat pada pengantaramuka Arduino IDE. Bagi memudahkan proses perekodan, keenam-enam kedudukan dimotosikal dinamakan seperti Jadual 2 berikut. Jadual 2:Nama kedudukan pusat pada motosikal Kedudukan Singkatan Nama 1500rpm 5000rpm Pemegang kanan (pendikit) Ra1 Ra2 Pemijak pemandu kanan (brek belakang) Rb1 Rb2 Pemijak pembonceng kanan Rc1 Rc2 Pemegang kiri (klac) La1 La2 Pemijak pemandu kiri (gear) Lb1 Lb2 Pemijak pembonceng kiri Lc1 Lc2 4. KEPUTUSAN DAN PERBINCANGAN 4.1 Graf Getaran Getaran diukur pada enam kedudukan berbeza di motosikal subjek. Kesemua enam kedudukan ini merekodkan dua bacaan getaran iaitu pada kelajuan enjin 1500rpm dan juga 5000rpm. Graf bagi setiap rekod getaran boleh dirujuk pada Rajah 6 (a - l) berikut.
178
179
180
181 Rajah 6 (a - 1): Graf amplitud getaran pada kedudukan Ra1 hingga Lc2 4.2 Ringkasan amplitud Berdasarkan data asas getaran yang boleh dilihat di Rajah 6 (a - l), Jadual 3 berikut merupakan rumusan amplitud dan puncak ke puncak getaran bagi kesemua keadaan dan kedudukan serta pada semua paksi x, y dan z.
182 Jadual 3: Nilai getaran (m/s²) pada semua kedudukan pusat pengukuran Kedudukan Nama Amplitud paksi X Puncak ke puncak paksi X Amplitud paksi Y Puncak ke puncak paksi Y Amplitud paksi Z Puncak ke puncak paksi Z Pemegang Ra1 7 14 4.5 10 1.8 3.6 La1 5 9 7 12 4 6 Ra2 50 92 36 66 5 8 La2 38 71 60 108 28 36 Pemijak pemandu Rb1 15 25 26 50 34 66 Lb1 15 30 17 29 46 76 Rb2 95 170 100 190 65 130 Lb2 140 265 75 140 130 250 Pemijak pembonceng Rc1 52 92 55 93 8 16 Lc1 34 64 34 61 11 21 Rc2 50 94 75 137 25 42 Lc2 68 124 60 106 41 69 4.3 Perbincangan Berdasarkan rumusan yang diperolehi, secara keseluruhannya getaran adalah lebih tinggi pada putaran enjin yang tinggi bagi semua pusat kedudukan. Namun begitu, kajian ini menunjukkan getaran pada kedudukan pemijak pembonceng semasa enjin dalam putaran tinggi tidak terlalu banyak perbezaan berbanding dengan dalam keadaan enjin putaran idle. Manakala tahap getaran tertinggi didapati adalah pada kedudukan pemijak pemandu disebabkan oleh pautan secara langsung tempat pemijak tersebut kepada kotak enjin motosikal. Pada kedudukan yang sama juga, dapat dikenalpasti bahawa kedudukan pemijak pemandu disebelah kiri lebih besar getaran terutamanya pada paksi x dan paksi z apabila putaran enjin dilajukan berbanding pemijak pemandu sebelah kanan. Sementara itu, getaran sekata paksi x dan paksi y direkodkan pada semua kedudukan tetapi bagi paksi z, hanya getaran berskala rendah direkodkan pada dua kedudukan masing-masing di pemegang dan juga pemijak pembongceng kerana kedua-dua kedudukan ini tidak dipautkan terus pada enjin motosikal. Secara keseluruhan, getaran paling besar dikesan pada hala paksi x. Manakala pada hala paksi y getaran yang dikesan sedikit rendah dari paksi x. Sementara itu, hala getaran pada paksi z pula merekodkan bacaan keseluruhan 71% lebih rendah dari purata getaran hala kedua-dua paksi x dan y. Perbandingan getaran pada ketiga-tiga kedudukan pula merekodkan getaran paling tinggi dikesan pada pusat pemijak pemandu dan getaran paling rendah pula dikenalpasti pada bahagian pemegang motosikal. Dapatan ini menunjukkan walaupun pada bahagian pemijak pemandu telah diletakkan getah bagi mengurangkan kebolehpindahan getaran kepada pemandu, bacaan yang direkodkan masih lagi tinggi berbandi dengan dua kedudukan pusat kawalan yang lain. Selain itu, berdasarkan keseluruhan kajian ini dapat dilihat bahawa pada motosikal jenis Honda RS150 ini, bahagian sebelah kiri merekodkan getaran 14% lebih tinggi dari bahagian sebelah kanan motosikal. Walaupun begitu, perbezaan getaran ini tidaklah terlalu tinggi dan tidak memberi impak besar terhadap pengendali motosikal.
183 5. KESIMPULAN Kajian ini menunjukkan terdapat perbezaan yang tidak sekata pada getaran yang direkodkan di setiap pusat kawalan tangan dan kaki motosikal jenis kapcai ini. Namun begitu, kajian ini membuktikan bahawa kelajuan putaran enjin yang lebih tinggi pada motosikal kapcai turut meningkatkan bacaan getaran yang diukur. Dapatan ini ada perbezaan dengan dapatan dari sebahagian penyelidik lain yang menjalankan kajian melibatkan pengukuran getaran dari enjin jenis pembakaran dalam. Hasil kajian ini turut merekodkan getaran yang dihasil pada kedudukan yang berpaut terus pada enjin adalah lebih tinggi dari kedudukan pautan pada kerangka utama. Manakala kedudukan pemegang yang dihubungkan menggunakan gandar merekodkan bacaan getaran lebih rendah. Selain itu, kajian ini turut membuktikan penggunaan jangka pecut yang berkos rendah mampu untuk mengukur getaran dalam skala yang sama serta lebih fleksibel berbanding jangka pecut lain yang berharga jauh lebih mahal. PENGHARGAAN Setinggi-tinggi penghargaan diberikan kepada pihak Makmal Bunyi Dan Getaran, Pusat Pengajian Kejuruteraan Mekanik, Universiti Sains Malaysia khususnya Dr. Ahmad Zhafran Bin Ahmad Mazlan yang banyak memberikan rujukan terhadap kajian ini. Selain itu, penghargaan ini turut diberikan kepada saudara Amirul Azhajzul Bin Gilok yang turut membantu dalam membangunkan set pengukuran getaran menggunakan jangka pecut MPU9250 ini. RUJUKAN Griffin, Michael & Howarth, Henrietta & Pitts, P.M. & Fischer, S. & Kaulbars, U. & Donati, P.M. & Bereton, P.F.. (2006). Guide to good practice on hand-arm vibration. EU Good Practice Guide HAV. K. Guru Manikandan, K. Pannirselvam, Jack J. Kenned & C. Suresh Kumar. (2021). Investigation on suitability of MEMS based accelerometer for vibration measurements. Materials Today: Proceedings (45), 6183–6192. ISSN 2214-7853, https://doi.org/10.1016/j.matpr.2020.10.506. Tjhai, Chandra & O'Keefe, Kyle. (2019). Using Step Size and Lower Limb Segment Orientation from Multiple Low-Cost Wearable Inertial/Magnetic Sensors for Pedestrian Navigation. Sensors, 19, 3140.https://doi.org/10.3390/s19143140 Hayouni, Mohamed & Vuong, Tan-Hoa & Choubani, Fethi. (2022). Wireless IoT universal approach based on Allan variance method for detection of artificial vibration signatures of a DC motor's shaft and reconstruction of the reference signal. IET Wireless Sensor Systems (12), 81-92. https://doi.org/10.1049/wss2.12038. Looney Mark. (2014). An introduction to MEMS vibration monitoring. Analog Dialogue, Vol. 48, Issue 6, 2014. 1-3. Analog Device Inc. Komarizadehasl, Seyedmilad, Behnam Mobaraki, Haiying Ma, Jose-Antonio Lozano-Galant, and Jose Turmo. (2021). Development of a Low-Cost System for the Accurate Measurement of Structural Vibrations. Sensors 21, no. 18: 6191. https://doi.org/10.3390/s21186191 MPU-9250 Product Specification Revision 1.1: InvenSense Inc. Indianapolis, CA 95110 U.S.A. (2016) Dinh Vinh Man Nguyen, Anh Tuan Vu, Veerle Ross, Tom Brijs, Geert Wets, Kris Brijs, Small-displacement motorcycle crashes and risky ridership in Vietnam: Findings from a focus group and in-depth interview study, Safety Science, Volume 152, 2022, 105514, ISSN 0925-7535 https://doi.org/10.1016/j.ssci.2021.105514.
184 NM Usamah, AZA Mazlan & ZM Ripin. (2022) Investigation of Motorcycle Handle Vibration Attenuation Using a Suspended Handlebar With Different Rubber Mount Characteristics. International Journal of Acoustics and Vibration, Vol. 27, No. 3, 2022, 276-284. https://doi.org/10.20855/ijav.2022.27.31872
185 PERSEPSI PELAJAR TERHADAP PENGGUNAAN APLIKASI TELEFON BIMBIT (MOBILE APPS ECOMAC) DALAM PENGAJARAN DAN PEMBELAJARAN BAGI KURSUS EKONOMI DI POLITEKNIK MALAYSIA Norlela binti Zaman1* Rosamiza binti Meor Razak2 1-2 Jabatan Perdagangan, Politeknik Sultan Salahuddin Abdul Aziz Shah , Selangor *Emel: [email protected] ABSTRAK Kursus Makroekonomi merupakan salah satu kursus wajib yang perlu diambil oleh pelajar-pelajar Program Diploma Jabatan Perdagangan di politeknik.Kaedah Pengajaran dan pembelajaran (PdP) sebelum ini menggunakan pembentangan slaid Power Point yang disediakan oleh pensyarah kursus di sampingbuku-buku rujukan yang terdapat di perpustakaan. Walaupun kaedah ini dapat diterima pelajar akan tetapi kaedah ini boleh dianggap sebagai kaedah tradisional yang masih digunakan sehingga kini dan ia mempunyai cabaran yang tersendiri di erapandemik Covid 19 ini. Kaedah ini dilihat tidak lagi memberikan daya tarikan yang tinggi terhadap Pengajaran dan pembelajaran (PdP) kepada pelajar. Justeru itu, bagi menimbulkan minat dan menarik perhatian pelajar terhadap kursus ini, satu inovasi yang dinamakan Ecomac telah diperkenalkan dan melalui inovasi ini, pelajar akan dapat mempelajari Kursus dengan menggunakan aplikasi telefon bimbit . Dengan penggunaan aplikasi telefon bimbit Ecomac ini, Ia menjadikan PdP untuk kursus Makroekonomi lebih menarik dan menyeronokkan. Ecomac ini dapat membantu memberi latihan bagi meningkatkan kefahaman pelajar terhadap konsep di dalam makroekonomi. Inovasi ini diharapkan dapat meningkatkan kefahaman pelajar, memudahkan pelajar untuk mengulangkaji dan menjadikan Kursus Makroekonomi antara kursus yang menarik dan mudah difahami. Soal-selidik mengenai persepsi pelajar terhadap penggunaan ecomac ini telah dijalankan dan hasil dapatan menunjukkan sebilangan besar pelajar bersetuju bahawa penggunaan ecomac mampu meningkatkan minat danfokus dalam pengajaran dan pembelajaran. Dapatan ini membuktikan bahawa ecomac relevan digunakan sebagai bahan bantu mengajar dan perlu diperluaskan penggunaanya bagi mencapai impak positif didalam aktiviti pengajaran dan pembelajaran. Kata Kunci: Ekonomi, Ecomac. 1. PENGENALAN Dunia pendidikan di Malaysia telah mengalami perubahan yang besar di dalam erapandemik COVID-19 masa kini. Institusi pendidikan di Malaysia telah menjalankan pelbagai inisiatif bagi memastikan kelangsungan proses pembelajaran dapat diteruskan antaranya adalah dengan memberi penekanan kepada pengajaran berasaskan teknologi maklumat dan komunikasi (TMK). Perubahan ini telah memberi kesan kepada kaedah mendapatkan maklumat dimana pengguna lebih cenderung mendapatkan maklumat menggunakan teknologi dengan lebih pantas dan tanpa batasan. Selain itu, teknologi maklumat dan komunikasi juga menggalakkan pendekatan pengajaran yang kreatif, inovatif, dinamik serta menghiburkan sebagai medium utama yang berupaya menarik perhatian pelajar dalam proses pengajaran dan pembelajaran abad ke-21 termasuklah di institusi pendidikan tinggi, peringkatsekolah menengah bahkan di peringkat
186 sekolah rendah (Rusli et al., 2021). Kenyataan ini disokong oleh Mohd Salleh dan Mukhari (2007) yang menyatakan bahawa pelajar masa kini lebih tertarik kepada pendekatan pengajaran yang lebih interaktif dan berbeza dengan kaedah tradisional yang hanya berpusatkan pada guru semata-mata. Antara transformasi yang dilaksanakan dalam pengajaran dan pembelajaran ialah menggunakan mutimedia sebagai alat bahan bantu mengajar (ABBM). ABBM terbahagi kepada dua kategori iaitu elektronik dan bukan elektronik. Contoh bagi kategori elektronik adalah radio, televisyen, projektor slaid, video dan alat berbantukan komputer. Manakala kategori bukan elektronik terdiri dari adalah kad imbasan, model, jurnal, gambar, dan majalah yang berkaitan dengan pengajaran yang diajar (Mohamad & Musa, 2013). Menurut Savage dan Vogel (2013) memberi definasi multimedia sebagai gabungan proses pembangunan dan penghantaran maklumat dalam bentuk audio, video, grafik, teks, imej dan animasi menggunakan peranti digital. Ibrahim (2013) juga menyatakan penggunaan elemen multimedia seperti teks, audio, video, animasi, grafik, gambar dan animasi yang interaktif dapat merangsang minat pelajar untuk mengikuti proses pengajaran dan pembelajaran. Sejajar dengan situasi masa kini, penggunaan aplikasi mudah alih dalam proses pengajaran dan pembelajaran dilihat lebih relevan berbanding dengan buku bercetak. Oleh itu, kajian ini dijalankan untuk meninjau persepsi pelajar terhadap penggunaan aplikasi mudah alih ecomac bagi kursus makroekonomi. Kursus Makroekonomi merupakan kursus teras bagi pelajar Diploma Semester Dua (2) semua program Diploma yang ditawarkan di Jabatan Perdagangan Politeknik Malaysia. Kursus ini memberi pendedahan berkenaan konsep pengiraan pendapatan negara dalam bab 2 makroekonomi. Inovasi ini dihasilkan sebagai alat bantu pengajaran dan pembelajaran (PdP) bagi memudahkan para pensyarah dan pelajar dalam proses PdP kursus berkenaan. 2. ULASAN LITERATUR Pelbagai kaedah dan pendekatan diketengahkan bagi memastikan proses pembelajaran dan pengajaran Makroekonomi di Politeknik lebih menarik dan efisien. Seiring dengan transformasi di dalam bidang digital, para pensyarah mula tertarik untuk menggabungkan proses PdP dengan teknologi digital, seperti aplikasi atas talian (Online Application) sama ada secara percuma mahupun secara berbayar. Menurut Norakyairee et al. (2018), perkembangan teknologi maklumat dilihat dapat memberikan impak dan potensi yang besar terutama dalam bidang pendidikan. Pengaplikasian ICT dilihat amat penting dalam sektor pendidikan kerana ia mampu dijadikan medium pengantaraan yang baik antara guru dan pelajar. COVID-19 yang berlaku telah memberi implikasi yang besar kepada insitusi pendidikan seperti pihak tenaga pengajar dan pelajar dalam menjalani proses pengajaran dan pembelajaran (PdP) seperti kaedah biasa iaitu secara bersemuka. Ianya juga mampu menjadikan teknologi sebagai pengantara bagi mencapai matlamat pendidikan dan demi memastikan para pelajar tidak ketinggalan dalam pendidikan mereka walaupun sewaktu negara dilanda pandemic COVID-19. Pandemik Covid-19 telah menyebabkan transformasi secara besar-besaran terhadap lanskap pendidikan negara dimana penggunaan aplikasi atas talian serta pembelajaran menggunakan teknologi telah digunakan secara meluas bagi memastikan para pelajar dapat meneruskan aktiviti pengajaran dan pembelajaran. Semua institusi pendidikan di Malaysia kini berusaha untuk meluaskan lagi penggunaan ICT dalam pendidikan dengan menyediakan infrastruktur ICT yang mencukupi di setiap sekolah dan institusi pengajian tinggi bagi menjalankan pengajaran dan pembelajaran atas talian.
187 Selain itu, institusi pendidikan juga telah diminta dan disarankan untuk menyusun semula pentaksiran serta kurikulum dalam menerapkan elemen ICT sebagai proses pengajaran dan pembelajaran, mengadakan latihan kepada tenaga pengajar untuk meningkatkan pengetahuan dan kemahiran mereka dalam ICT (Roslin & Salleh, 2021). Terdahulu, penggunaan kaedah pengajaran secara tradisional telah digunakan secara meluas berbanding penggunaan teknologi maklumat terkini. Namun, penggunaan teknologi moden pada masa kini dilihat lebih relevan dan efektifbagi memastikan kelangsungan aktiviti pembelajaran di kala pandemik COVID-19 yang masih belum berakhir ini. Pengajar memainkan peranan penting dengan memanfaatkan Bahan Bantu Mengajar (BBM) berteknologi dalam menghasilkan pengajaran yang interaktif (Muhd Zulhilmi et al. 2020). Walaupun terdapat banyak kajian yang dilaksanakan menunjukkan kelebihan penggunaan BBM berteknologi, namun tahap penggunaan teknologi masih pada tahap sederhana (Haron et al., 2020). Oleh itu, bagi mempelbagaikan kaedah pengajaran dan pembelajaran secara digital, penggunaan aplikasi mudah alih dilihat berperanan untuk menbentuk perubahan daripada pengajaran tradisional. kepada pengajaran berasaskan teknologi, aplikasi mudah alih menggunakan multimedia dan lebih berinteraktif untuk menghasilkan kesan yang positif kepada pelajar. secara umumnya, e-Pembelajaran merupakan penyampaian pendidikan melalui internet dengan menggunakan komputer. Skop penggunaannya menjangkau lebih daripada konsep pembelajaran berbentuk komputer atau multimedia. Pendekatan pengajaran ini juga turut dibudayakan danditerapkan di seluruh institusi pengajian bagi memenuhi keperluan terhadap pembelajaran sepanjang hayat. Situasi ini kemudiannya mewujudkan peluang baru, iaitu pembelajaran jarakjauh yang mana telah diamalkan di institusi pengajian tinggi tempatan seperti Universiti Terbuka Malaysia (OUM) (Zoraini et al. 2010). Aspek ini secara tidak langsung akan meningkatkan produktiviti kemahiran individu dalam kehidupan seharian serta memupuk amalan pembelajaran secara berterusan Rentetan dari penggunaan kaedah pembelajaran jarak jauh dan e-pembelajaran, dunia pendidikan cuba untuk meneroka dimensi pembelajaran bagi pengguna yang menginginkan pembelajaran setiap masa dan di mana-mana. Lalu, lahirlah istilah kaedah pembelajaran secara mudah alih atau dipanggil dengan m-pembelajaran (Brown 2005; Keegan 2005). Kaedah m-pembelajaran ini lebih bersifat kepada pembelajaran kendiri (self-learning) yang menggunakan alat mudah alih seperti telefon bimbit, personal digital assistant (PDA), Palm Talk dan lain-lain sebagai alat pembelajaran (Wagner 2008). Menerusi penggunaan kaedah m-pembelajaran, proses pembelajaran bukan lagi tertumpu dalam satu platform atau hanya terhad di dalam sesebuah bilik darjah tetapi, m-pembelajaran lebih bercorakkan just-in-time, just-in-case, on-the-move dan on-demand (et al. 2012; Traxler 2007). Hal ini menunjukkan bahawa penggunaan alat mudah alih lebih mudah menjadikan pembelajaran berlaku pada bila-bila masa dan mana-mana tempat berbanding dengan penggunaan buku notayang mudah rosak dan tidak bertahan lama (Ahmad Sobri 2010; Shafiza 2007). Keadaan ini menunjukkan bahawa alat mudah alih seperti telefon bimbit, Pocket PC dan lain-lain mempunyai kelebihan dari bahan yang bersifat konvensional. 3. METODOLOGI Artikel ini menggunakan bentuk kajian tinjauan dengan menggunakan kaedah deskriptif. Dalam artikel ini, pengkaji menggunakan pendekatan kuantitatif bagi mengukur penerimaan pelajar terhadap kaedah pengajaran secara tradisional berbanding dengan pengajaran secara interaktif dan juga mengukur persepsi pelajar terhadap penggunaan aplikasi mudah alih bagi kursus Makroekonomi di Politeknik Sultan Salahuddin Abdul Aziz Shah. 33 orang pelajar telah