UP COE - NEC Technical Bulletin 2019

process of collecting, analyzing, and the disaster information and then the a (4)
reporting information regarding the operation prioritization scoring scheme called a Tweet
of an individual, group, or organization. The Prioritization Score (TPS) that assigns scores to
Department of Finance is interested in the the classified tweets according to urgency.
performance of the Bureau of Customs Five test cases were used for verification and
(BOC), particularly its collections. As one of validation purposes. Classification was done
the DOF‟s attached agencies, the BOC is using a direct multiclass and a transformation
second only to the Bureau of Internal to binary methods which produced average
Revenue in terms of revenue-generation for accuracy of 69.22% and 78.60%, respectively.
the government. The Financial Analytics and The prioritization module provided ranked
Intelligence (FAI) Unit of the DOF creates in- scored tweets based on the TPS which could
depth analysis of the BOC‟s collections using be used by different disaster response owners.
various sources, including the transactional The final output gave promising results to
department of the Bureau. The process of which local disaster managers can utilize
compiling and summarizing the transaction during planning and responding to disasters.
entries of the Bureau is a tedious job that
takes a lot of time. Microsoft Excel, the *Co-authors: Eugene Rex L. Jalao2, Joanna Z.
software being currently used, is prone to Resurreccion
crashes with the large volumes of data being
handled. Procurement of more appropriate ERICKSON L. LLAGUNO
software cannot be done right away. Focus Global Inc. Professorial Chair in
Ultimately, the current set-up takes too long Engineering
for a report that has at least ten variations
every month. This proposed project aims to “Understanding the Factors Contributing to
create a Customs collection dashboard that the Increase Over the Years in the Number of
can aid the FAI unit in their outputs by storing Students Graduating with Latin Honors in the
the Customs transaction entries in a single Bachelor of Science in IE Program ”
data warehouse that can be easily queried
from by an accessible dashboard. A Abstract: Year 2019 saw 43% of the total
backend database on Microsoft SQL and a graduates of the UP Diliman Bachelor of
frontend of R Shiny were used to build the Science in Industrial Engineering (BSIE)
dashboard for recurring reports. program finished with Latin Honors -- the
highest in the history of the program. Of the
*Co-author: Maria Regina A. Muñoz 111 BSIE graduates, 1 graduated Summa Cum
Laude, 9 with Magna Cum Laude Honors and
RAYMOND FRETH A. LAGRIA 38 finished Cum Laude.
Dr. Luis D. Pascual Professorial Chair in Systems With this remarkable performance, it cannot
Thinking and System Dynamics be helped that questions on the factors
contributing to this achievement were
“A Lookup-Based Decision Support System for brought up. This study was conducted
Classification and Prioritization of Disaster- specifically to understand these factors or
Related Tweets for Disaster Response”* drivers.
Based on the results, there was not a single
Abstract: This research proposed a learning factor that this can be attributed to, rather it
text mining framework that would be able to was the confluence of events and factors
handle multilingual text, classify according to that paved the way for the performance. It
disaster related information and prioritized cannot be denied that the University gets the
according to the urgency. The framework best raw materials -- its students -- from the
includes four components namely, the (1) pre pool. This batch had the highest University
-processing component, the (2) topics Predicted Grade (UPG) among BSIE UPCAT
modelling module, the (3) classification qualifiers in the last 20 years.
module that classifies the tweets according to As shown in the survey with Latin honor

UP COLLEGE OF ENGINEERING TECHNICAL BULLETIN 2019 43

recipients, proper time management was key LOWELL L. LORENZO
to their performance. Coupled this with the Stephen D. Sy Professorial Chair
right motivation and attitude, amidst an
environment where there was healthy “A Product Assortment Planning Model
competition among batchmates, not Framework Incorporating Variety and a
surprisingly more graduated with honors. Substitution Mechanism”
The decreasing failure rate of the usually
challenging IE courses also went well for the Abstract: The product assortment planning
students. While it may be difficult to find the problem (PAP) is a multifaceted problem
real reason for the decreasing rate – it could wherein tradeoffs must be made
be professors getting more lenient, students appropriately among different factors in order
getting brighter, change in the assessment to achieve the desired objective of the
method / content/ delivery – one thing is decision maker. For a specific store-based
clear, these subjects were not viewed as grocery retailer or supermarket, there is a
„stoppers‟ anymore and that getting high need to offer a large variety of products while
grades for them was no longer as maintaining profitability. By balancing the
challenging. trade-off between product proliferation and
The current system of selecting your own the store‟s limited shelf space capacity, a
menu of GE courses to take also favored the delisting strategy called internal SKU
students as they were able to enlist in classes rationalization (ISR) is developed to remove
handled by teachers known to be generous in unprofitable SKUs from the store‟s assortment.
giving high grades. With technology and By doing so, the grocery retailer can gain
internet, information on the teachers‟ style short-term profitability because of the
and grading system are passed on reduction in carrying costs and the additional
immediately for everyone to see and check profit gained from the transferable demand
who is the right professor to pick and avoid. of delisted SKUs defined by an assortment-
For these graduates, these were very valuable based substitution mechanism wherein a
information during their planning on how to portion of the delisted SKUs demand can be
bank on high grades in GE courses. substituted by the remaining listed SKUs in the
The value of the available resources in assortment. A Grocery Retailing Product
program-based organizations cannot be Assortment Planning model framework
overemphasized as it is in the top 3 answers in focusing on Internal SKU Rationalization
the survey. The organizations painstakingly (GRAP-ISR) is presented to address the
built their databases of resource materials per solution approach for this problem.
course including copies of previous exams,
solved problem sets and the like that really LORENZO, SIMON ANTHONY D.
helped these students prepare. UPIEAA Professorial Chair
The support system provided by family,
friends, classmates and groupmates was also “A Threshold-Based Dynamic Customer
important as it helped them not only just to Redirection Rule for Minimizing Extra Effort in
survive the rigors of the program but to Bicycle-Sharing Systems”
perform at the highest level as well.
Truly, the significant proportion of students Abstract: Bicycle sharing is a new type of
that graduated with Latin honors in 2019 was transportation system that has been
by no means incidental. It was a result of the developing over the years. These systems
combination of factors that aided motivated tend to have low service levels if manual bike
and diligent students who thrived in an level balancing is not done, resulting to
atmosphere where healthy competition schemes such as static and dynamic bike
existed. repositioning, as well as customer redirection.
While customer redirection allows for a high
44 system service level, it asks customers to travel
distances they would otherwise not need to.

UP COLLEGE OF ENGINEERING TECHNICAL BULLETIN 2019

The study aims to produce a solution to the ADELINE A. PACIA
extra effort being asked from the customer by Juan Jr. & Rosario Halili-Quintos Professorial
producing a rule that would minimize the said Chair
quantity, while still maintaining a target
service level of the system. The proposed rule “The Assessment and Proposed Re-Design of
entails the redirection of both the customer‟s the UP Diliman Pilot Food Plant and Food
trip origin and destination, using dynamic Innovation Facility”
thresholds based on the stations forecasted
supply and demand for bikes. A simulation Abstract: As the national university, the
model was used to evaluate the University of the Philippines is mandated to
effectiveness of the proposed rule. Results perform its unique and distinctive leadership
show that the new rule was able to reduce in higher education and development. UP
the system average extra effort for customers Diliman, as the main campus, should thus
by as much as 43.35% while maintaining the take the lead in setting academic standards
service level, over 100 replications of the and initiating innovations in teaching,
simulation. Thus, the rule brought about by research, and faculty development. UPD is set
the study is the best among all existing rules, in to fulfill this aim with the Technology Transfer
terms of minimizing extra effort, as of the time and Business Development Office, which is
of writing. tasked to facilitate and manage the research
output of the university community for
IRIS ANN G. MARTINEZ intellectual property protection and
Prof. Fortunato Tanseco Dela Peña technology transfer, either through
Professorial Chair in Productivity Engineering commercialization or utilization for public
good. This paper assesses the challenges
“A Proposal for the Development of Easily facing UPD TTBDO today and provides
Available Operations Management Solutions recommendations on how the collective
Commonly Needed by Small or Medium effort of everyone within the university, as well
Philippine Business Organizations” as collaboration with relevant government
agencies and industry partners, can build the
Abstract: This study proposes a way to ecosystem needed to enable IP protection
develop Operations Management solutions. and technology transfer for national
The objective of this paper is to propose an development.
efficient way of providing solutions to
Operations Management problems that are JHOANNA Z. RESURRECCION
commonly encountered by small or medium Marubeni UP Centennial Professorial Chair
Philippine business organizations. The
underlying hypothesis to the proposal is that “Decision and Risk Modeling for Implementing
any solution or any technology is made up of Regional Environmental Protection Policies on
two components: (a) common (core) Interdependent Economic and Infrastructure
component and (b) user-specific Systems”*
component. To show that common
operations management problems are Abstract: Risk mitigation policies for
encountered by Philippine business environmental protection and rehabilitation
organizations that can be addressed by encompass reduction of use, limitation of
common solutions, the student project studies exposure, removal or replacement of
in AY 2018-2019 were analyzed. This was infrastructure and technology and even the
validated by the characterization of student closure of establishments. However,
projects for AY 2017-2018. underlying regional sector interdependencies
may cause these policies to induce ripple
UP COLLEGE OF ENGINEERING TECHNICAL BULLETIN 2019 effects through disruption in the functions of
existing economic and infrastructure sectors.
The effects may vary from income losses and

45

decreased utilization to mounting debts and (PENRO) and municipal (MENRO) levels and
hunger to the workforce. Decision support the local level disaster risk management
and impact analysis to minimize these ripple (LLDRM). An assessment tool was developed
effects while reaching the environmental goal and used in three mining sites. To compare
are necessary especially for disruptions that their agreement on safety, the study used
affect highly interdependent systems. This Cohen's kappa, a statistical tool for assessing
research develops a framework that inter-rater reliability when observing
evaluates the criticality of individual sectors categorical variables. There was a big
resulting from partial to full disruption of difference in the knowledge of safety and
operations due to closure policies from safety standards for miners and monitoring
rehabilitation. An inoperability input-output officials.
model is applied to determine direct and
indirect economic impacts in a network of *Co-author: Isachar Bernaldez
interdependent sectors. It has been made
capable to accommodate variations in
inoperability periods based on modifications
in the timing of partial and full closure
implementation. A case is demonstrated for
the recent closure of the Philippine resort
island of Boracay, one of the nation‟s major
tourist destinations as part of the
government‟s efforts in the island‟s
environmental rehabilitation. The framework
can help policy makers and enforcers
estimate the consequences of rehabilitation
and closure policies as well as prioritize critical
sectors for government support programs. The
resulting framework has flexibility and
scalability over other disruption-events and
other economic regions.

*Co-author: Joost R. Santos

VIRGINIA J. SORIANO UP COLLEGE OF ENGINEERING TECHNICAL BULLETIN 2019
Pedro & Francisca Maniego Professorial Chair

“The Gap in the Safety Knowledge Between
the Small-scale Miners and Local Mining
Monitoring Body in the Philippines”*

Abstract: Small-scale mining is one of the most
unsafe human activities in the Philippines. This
paper aims to measure the gap between the
concept of safety among miners and the
local government mining monitoring body.
This study checked the difference in
percentage of exposure of miners on hazards
in mining sites based on their perception and
the perception of officials of local
government mining monitoring body
specifically the Department of Environment
and Natural Resources at the provincial

46

UP COLLEGE OF ENGINEERING TECHNICAL BULLETIN 2019 47

BINOE E. ABUAN conventional multi-stage system of the same
HB Reyes ME Centennial Professorial Chair evaporator and condenser temperatures. The
ejector components were modelled using
“The Performance and Hydrodynamics in one-dimensional single and two-phase flows
Unsteady Flow of a Horizontal Axis Tidal incorporated with friction. Stepwise
Turbine”* calculation along the flow axis was
conducted to determine the flow conditions
*Paper published in Renewable Energy, an and optimize geometry of the components
International Joumal. https://doi.org/10.1016/ relative to the performance of each
[email protected]. component, the ejector and the resulting
COP of an entire setup. The thermodynamic
*Co-author: Robert J. Howell and transport parameters corresponding to
known state points were determined using an
JUVY A. BALBARONA established standard reference database.
Renato M. Tanseco Professorial Chair Evaporating temperature of -40 to -60 degree
Celsius and condensing temperature of 60 to
“Cupric Oxide Nanostructures from Plasma 120 degree Celsius were used. Systems of
Surface Modification of Copper”* multi-stage compression with one and two
levels or temperatures of evaporation were
Paper published in Biomimetics 2019, 4, 42; studied. Computation results showed that the
doi:10.3390/biomimetics4020042. https:// COPs of the multi-stage systems with single
www.mdpi.com/journal/biomimetics. and double evaporators were 20% and 26%
higher than those of conventional ones. The
*Co-authors: Hernando S. Salapare III, Léo ejector systems with single and double
Clerc, Pierre Bassoleil, Arnaud Zenerino, Sonia evaporators yielded maximum COPs of 4.6
Amigoni, and Frédéric Guittard . and 5.8 at condenser and evaporator
temperatures of 60 and -40 degree Celsius,
MENANDRO S. BERANA respectively. The COP of the double
Lim Seh Leng Mechanical Engineering evaporator system is higher than that of the
Centennial Professorial Chair single one because of the additional flow in
the upper stage compressor coming from the
“Design of a Novel Multi-Stage Vapor higher stage evaporator that offsets the
Compression and Ejector-Enhanced drawback of increase in compressor power
Combined Cooling and Heating Cycle”* input by the increase in heating output.

Abstract: A novel system that features *Co-author: Mark William S. Mendoza
incorporation of ejectors in ammonia multi-
stage vapor compression cycle which is JENNIFER F. CALLANGA
intended for simultaneous cooling and Team Energy Professorial Chair
heating application was studied. An ejector is
placed in each compression stage to reduce “Analysis of Crack Propagation Under
the power input at that stage, and effectively, Different Die Tilt Configuration on a Small
the total power input. Furthermore, the output Outline Transistor”*
derived from the cycle will be multiplied to
more than double because of the combined Abstract: In today‟s microelectronic industry,
magnitude of heat contributed by the heat the increasing demand for miniaturization
removed during cooling and the heat added and high function integration poses a big
during heating. Finally, all of those challenge in maintaining the reliability of the
advantages lead to substantially higher package. It was found out that majority of
combined heating and cooling coefficient of the reliability problems can be attributed to
performance (COP) compared to that of thermal and mechanical loadings during
manufacturing and assembling process. Die
48
UP COLLEGE OF ENGINEERING TECHNICAL BULLETIN 2019

cracking and die tilting are two of the most superhydrophobic surface. The model is
common defects originating from this process developed by combining a power law
that affect the reliability of the electronic growth model, an exponentially decaying
packages. This study aims to investigate the population model, and a gaussian probability
influence of die tilting to the propensity of model for growth variations. The model is
crack propagation on the silicon die. In this validated against experiment data, with
research, the cooling phase of the die and correlations ranging from 88% to 94%. The
clip attach reflow of small outline transistor growth model can sufficiently describe the
was simulated using a finite element-based growth of drops from 0.02 mm to 0.1 mm but
software. An initial crack was incorporated in may be extrapolated to describe the growth
the silicon die model to show the of even smaller drops. The experiment data
imperfections acquired during manufacturing shows that drop size distribution or frequency
stage. J-integral (J) parameter of fracture distribution of drops of different sizes varies
mechanics was employed as a criterion for significantly with time and may be considered
the behavior of incipient cracks. With the pseudo-cyclic. The developed model
assumption that the die used in this study together with the sweep rate of drops
exhibits linear elastic, isotropic property, the sufficiently describes this behavior, and
calculated J-integral values were correlated consequently may also be used to better
to the energy release rate (G). The simulation estimate heat transfer rate due to dropwise
results showed that as the tilt angle increases, condensation.
there is also a significant increase in the value
of J-integral. Highest J value was observed on *Co-author: Juvy A. Balbarona
the maximum tilt angle. Moreover, this study
presents clear relationship between die HANNAH ERIKA R. DUCUSIN
strength and the specified failure factors; Leopoldo T. De Ocampo Professorial Chair in
crack and tilt. Mechanical Engineering
*Co-author: Hannah Erika R. Ducusin and
Manolo G. Mena “Investigation of Silicon Die Crack for Varying
Silicon Die Parameters and Die Attach
LOUIS ANGELO M. DANAO Material “*
Vicente Paterno ME Centennial Professorial
Chair Abstract: Demand for small sized, portable
electronic devices continually increases until
“Steady Wind Performance of a 5-Kw Three- today. Compact electronics would mean a
bladed H-rotor Darrieus Vertical Axis Wind reduction in size of semiconductors that
Turbine (VAWT) with Cambered Tubercle would translate to further shrinking of
Leading Edge (TLE) Blades”* components inside of it such as the small
outline diode (SOD) and the small outline
Paper published Energy.https:// transistor (SOT). This work utilized the finite
doi.org/10.1016/j.energy.2019.03.033 0360- element method with a fracture mechanics
5442/© 2019 Elsevier Ltd. approach to analyze the effect of varying
geometric parameters on the J-integral of an
*Co-author: Ian Carlo M. Lositaño. induced crack on the silicon die. Furthermore,
investigation of the effect of two die attach
GERALD JO C. DENOGA material, having different modulus of
Fernando N. Seriña Mechanical Engineering elasticity, on the crack propensity on the
Professorial Chair silicon die was done. The J-integral values
“Drop Size Distribution Model”* obtained generally showed a peak value
with the mid-sized silicon die whose die
Abstract: This study presents a mathematical attach material has higher modulus of
model of drop size distribution during elasticity. The J-integral value generally
dropwise condensation on a decreased with die thickness but was found

UP COLLEGE OF ENGINEERING TECHNICAL BULLETIN 2019 49

to be minimum at around 100 mm die KOSHNEIR S. JIMENEZ
thickness. A further reduction in thickness Legazpi Premium Development Corporation
resulted in an increase in J-integral. Results Professorial Chair in Energy Engineering
from the simulations will be aid in determining
the effect of these parameters on the “Development of a Simulation Program for
reliability of the package with respect to die Train Operations Analysis”
crack risk and can be utilized to guide
improvements on the existing package Abstract: With the worsening traffic condition
design. in Metro Manila and in other urban centers,
the country faces a growing need for higher
*Co-authors: Jennifer J. Fabular, Richard capacity and more efficient transportation.
Raymond N. Dimagiba, and Manolo G. Among the best solutions for the traffic
Mena. congestion problem in the Philippines is the
construction of railway systems that could
RODERAID T. IBAÑEZ meet the present and future demands for
Ruben Garcia Professorial Chair in Energy transportation. In this study, a simulation
Engineering program was developed that is able to
provide data on the movement of trains. The
“Tidal Current Resource Power Quantification data was then processed to determine delay,
using NAMRIA Data Sets of the Philippines”* passenger capacity and power consumption
of the railway vehicles in a double-track
Abstract: This study outlines the determination railway system. The output of the research
of tidal current resources in the Philippines by was a tool for analyzing current railway
means of quantifying the power potential of systems in terms of capacity and an aid to
different regions in the Philippines based on transport planners in the improvement and
the available data. The annual tidal current further development of the future railway
data are derived from the National Mapping systems. The input parameters of the program
and Resource Information Agency (NAMRIA) were the infrastructure (stations, station
publication of tide and tidal current tables. An distances and blocking distances), the
annual velocity profile with 1-hour time step is railway vehicle characteristics (train cars,
derived from the NAMRIA tidal current tables. passenger capacity, speed, acceleration
There are five major regions of straits and etc.) and the passenger demand. The
passages with high tidal current potential primary independent variables for the tests
namely, Basilan Strait, Cebu Harbor, Hinatuan were: (a) the speed of the trains, which
Passage, Iloilo Strait, and San Bernardino determines the blocking distances and the
Strait. Nine sets of tidal current turbines with minimum headway; and (b) the number of
varying capacities and power curves are trains, which determines the headway, in the
used in the estimation. Among the five major system. As the number of trains and headway
regions, San Bernardino Strait has the most increased with different speeds and blocking
promising site characteristics for power distances, the simulation program and the
generation. Using a 40 KW generic data processing algorithm generated the
hydrokinetic turbine, it can produce an following parameters: (a) the delay increase
annual mean power of 11.973 KW with in the operation of the trains; (b) the number
median of 4.576 KW and maximum power of of passengers served by the railway system;
40 KW. Information of the other major regions and (c) the power consumption the railway
are presented in the study. vehicles (obtained from Davis formula). The
result of a study is the development of a
*Co-authors: Ed Joshua G. Mañalac and simulation program.
Nadenne I. Chua.

50 UP COLLEGE OF ENGINEERING TECHNICAL BULLETIN 2019

FERDINAND G. MANEGDEG used four other vegetable oils which are RCO
Alejandro Melchor Professorial Chair (Refined Corn Oil), RPO(Refine Palm Oil), JFO
(Jahtropa Filtered Oil) and JME (Jathropa
“Design of a Residential Residual Waste Methyl Ester) in order to investigate the
Disposal and Energy Generation via Pyrolyzer possibility of their use in diesel engines. A 6.3
and Steam Rankine Cycle”* kW single-cylinder, four stroke cycle, direct
injection engine was used for the study. This
Abstract: The design study concerns the kind of engine is typically used in the
creation of a waste-to-energy conversion Philippines for different purposes such as
plant in the City of Muntinlupa to lessen the backup power for households, for boats,
amount of non-recyclable municipal solid pumps and for agriculture use. The specific
wastes that ends up in the landfill. Using the fuel consumption of the biodiesel blends
developed criteria, the cluster that can be compared to neat diesel fuel varied from -
used are the biodegradable and residual 15% to 15% with RCO and JME having higher
waste portions of the municipal solid wastes. SFC and JFO and RPO having lower SFC. Fuel
From the amount of waste generated, the conversion efficiency of the biodiesel blends
amount of energy that can be extracted is compared to neat diesel fuel varied from -
324 to 380 TJ. In consideration of the 12% to 12% with JFO and RPO having higher
processes for power generation, Rankine efficiency and RCO and JME having lower
cycle was seen as the best alternative efficiency. The power of the biodiesel blends
powerplant type to use the biogas and compared to neat diesel fuel varied from -7%
synthetic gas produced from the biodigester to 6% with RPO having lower power output,
and pyrolyzer, respectively. It is estimated that JFO having higher power output and JME
5.5 to 6.5 MW of electricity may be produced, and RCO having similar power output to neat
translating to a 500 million pesos of savings to diesel fuel. At full load condasition Neat Diesel
the government of Muntinlupa. The electricity Fuel blended with 15% Refined Palm Oil
generation project has a return of investment showed the greatest improvement in SFC
of 15% and a payback period of 4.5 years. while Neat Diesel Fuel blended with 10%
Jathropa Filtered Oil showed the best power
*Co-authors: Paolo Yves L. De Silos and output.
Jonathan R. Medrano
*Co-author: Amarlo Banania and Edwin N.
JOSE GABRIEL E. MERCADO Quiros.
Apolonio P. and Lorna L. Yson Professorial
Chair in Engineering EDWIN N. QUIROS
Federico E. Puno 2 Professorial Chair
“Experimental Study on Performance of a
Single-Cylinder Engine Fuelled with Diesel and “Performance Characteristics of Philippine
Vegetable Oil-Diesel Blends”* Hydrous Ethanol-Gasoline Blends: Preliminary
Findings”*
Abstract: Continuous demand for energy in
order to provide to an ever-increasing global Proceedings of the ASME 2019 13th
population calls for use of or integration of International Conference on Energy
other alternative sources of fuel other than Sustainability ES2019 July 14-17, 2019, Bellevue,
fossil fuels. Many countries all over the world WA, USA
use vegetable oils blended with neat diesel
as alternative and using these biofuels can *Co-author: John Luis Yu
help alleviate the dependence on fossil fuels
and lessen the emissions releases on the 51
environment. In the Philippines CME (Coconut
Methyl Ester) is the primary vegetable oil used
for biodiesel blends however in this study we

UP COLLEGE OF ENGINEERING TECHNICAL BULLETIN 2019

JOSEPH GERARD T. REYES assumption of multiple units for a turbine
Leopoldo V. Abis Professorial Chair installation results in the reduction of the
number of variables for the design and
“Heat Release Rate Analysis of NOx Emissions selection problem, and leads to a set of
from a Diesel Engine Running on Different possible solutions. The solutions which give
Coco-Methyl Ester Biodiesel Blend Ratios” specific speeds close to the optimum specific
speeds are considered the most suitable
Abstract: Varying CoME/neat diesel blends solution, having practical diameter and
were tested using a stock common-rail direct speed ranges. After this selection process,
ignition (CRDI) engine in a test bench and economics will be the next determining
subjected to 100% and 50% load conditions at variable for the design and selection process.
different set test speeds. NOx levels, Trial calculations indicate the results are
alongside those of other emissions, were reasonably comparable to existing
measured and analyzed using measured and installations..
calculated parameters such as fuel injection
timing, fuel injection pressures, injection
durations, and net heat release rates. Test
results showed that all the biodiesel blends
produced up to 29% more NOx than neat
diesel for all engine loads and speeds, despite
the sustained injection timings and injection
pressures managed by the engine‟s
electronic control unit. These results could be
attributed to the physical properties, such as
the densities, viscosities, speed of sound and
bulk moduli, of the biodiesel blends and the
corresponding response of the fuel injection
system during fuel spray and the engine used
in the tests.

PAUL L. RODGERS UP COLLEGE OF ENGINEERING TECHNICAL BULLETIN 2019
Quezon Power Philippines Professorial Chair in
Engineering

“Selection of Hydroelectric Turbines Based on
Speed””

Abstract: A process for hydroelectric turbine
selection based on specific speed is
proposed. The method determines the best
type of turbine to install, the number of units
to be installed, the operating speed and the
nominal diameter, based on known net head,
power requirement and frequency of
electricity. The specific speed and peripheral
velocity factor corresponding to maximum
turbine efficiency are correlated with the
available head, power production and
frequency of electricity required in the
installation. A tabulated form of solution
approach is used, assuming multiple units of
installation for each type of turbine. The

52

UP COLLEGE OF ENGINEERING TECHNICAL BULLETIN 2019 53

ALBERTO V. AMORSOLO JR. Abstract: This study investigates the effect of
Philex Mining Corp. UP Centennial Professorial electrostatic interactions in the separation of
Chair-1 magnetite and silica in aqueous media using
enhanced gravity concentration. Magnetite
“Morphological Study of Ultrasonic Treatment and silica suspensions at different coagulation
Effect on Electrodeposited Tin on Copper conditions were prepared and subjected to
Substrate”* enhanced gravity concentration using Falcon
L40 concentrator. Increased recovery of both
Abstract: Tin is widely used in the magnetite and silica was observed at pH 3
semiconductor and electronics industry in where attractive forces are strongest both for
electroplated form due to its corrosion one-component and two-component
resistance and solderability. However, tin is interactions. However, the increased recovery
prone to formation of sharp protrusions known of both particles caused a decrease in
as whiskers which can have undesirable separation efficiency at this condition. At pH
effects such as shorting of device structures. It 11 where repulsive forces are dominant for
has been reported that ultrasonication during both one-component and two-component
electroplating can mitigate whisker formation. interactions, recovery of both particles
In this study, pure tin was electroplated on a decreased. The highest separation efficiency
copper substrate using a 267 ml Hull cell of 64.1% was at pH 9. At this condition, two-
apparatus at constant total current of 3 component interactions were repulsive which
amperes at room temperature. Plating runs led to the increased removal of silica. The
were carried out using a pre-mixed attractive one-component interaction of the
SolderonTM matte tin plating bath with remaining magnetite particles led to its
sonication and without sonication. The increased agglomeration and, subsequently,
morphologies corresponding to regions with increased magnetite recovery and grade at
average current densities of about 130, 65, 32, this condition.
12 and 1.6 mA/cm2 were imaged using the
SEM. Samples were also subjected to *Co-authors: Herman D. Mendoza
additional characterization tests such as
optical microscopy, x-ray diffraction and MARY DONNABELLE L. BALELA
hardness testing. Selected plated samples Robert Cheng/Uratex Professorial Chair 2
were also subjected to a temperature cycle
test consisting of 50 cycles with each cycle “Improvements in the electroless deposition of
having a duration of 20 minutes: 10 minutes Ag nanowires in hot ethylene glycol for
at 100 oC and the other 10 minutes at 25 oC. resistive touchscreen device”*
Results revealed desirable effects of ultrasonic
treatment on the microstructure, texture and *Paper published in the Materials Research
also on the hardness of the plating at Bulletin, Volume 106. October 2018. pp. 446-
average current density of 1.6 mA/cm2. The 454. https://doi.org/10.1016/
temperature cycle test did not show any j.materresbull.2018.06.030.© 2018 Elsevier Ltd.
significant effect on the microstructure.
*Co-authors: Nathaniel De Guzman and
*Co-authors: Sergi L. Bantay and Aaron Manuel Ramos Jr.
Joshua S. Alacala

KARLO LEANDRO D. BALADAD JAN LOWELL P. BUQUIZ
Dr. Meliton V. Ordillas Jr. Professorial Chair in Enrique and Elena Ostrea Centennial
Metallurgical Engineering Professorial Chair

“Effect of Electrostatic Interactions in the “Electrochemical Corrosion of Pb Alloy In
Separation of Magnetite and Silica using Sulfuric Acid Solutions”
Enhanced Gravity Concentration”*
UP COLLEGE OF ENGINEERING TECHNICAL BULLETIN 2019
54

Abstract: Pb-Sn alloys are one of the primary ELIGIA D. CLEMENTE
materials for the positive grids of automotive Semirara Professorial Chair in Wall Mining
batteries. Various studies have been done to
improve the mechanical and “Challenges in the Philippines Mining Industry“*
electrochemical properties of such alloys.
Despite these developments, corrosion of the Abstract: With the institution of the Philippine
positive grids remains to be one of the main Mining Act (PMA) in 1995, the Philippine
causes of battery failure. The study aims to government has laid down the regulatory
determine the corrosion behavior of different basis for the control of the industry in all
parts of an as-cast Pb-Sn alloy used in service aspects concerning the economic,
to provide insights on improving grid design environmental, social and cultural issues of the
and casting conditions. Electrochemical industry. Subsequent laws, however, did not
Impedance Spectroscopy (EIS) was used to consider the possibility of conflicts with the
determine the charge transfer resistance (RCT) established provisions of the PMA.
and polarization resistance (RP) of two
different grid locations at 15% and 25% (V/V) The Philippine Mining Act (PMA) is premised on
H2SO4, and 28°C and 40°C. Results showed the doctrine that all mineral lands are owned
that the charge transfer resistance (RCT) by the state but are open to contractors on
decreased with an increase in working the basis of revenue sharing, and a company
temperature. The decrease in RCT may be interested in mining operations can enter into
associated with the decrease in active an agreement with the government to exploit
porous sites due to the formation of a more and develop the land. The revenues from the
compact PbSO4 layer. On the other hand, the mining operations are shared not only with the
polarization resistance (RP) increased with the national government but also with the local
increase in acid temperature and government units (LGUs) and the barangays in
temperature for both grid locations. In the host and neighboring communities. Aside
addition, The RP values at location B are from the provisions on mining agreements, the
higher than in location A. The maximum RP of law also lays down various measures to
510.15 Ω∙cm2 was determined at location B at protect the environment and the stakeholders
25% (V/V) H2SO4 and 40°C. The RP increase of the mining sector and defines areas where
may also be associated with the formation of mining can be allowed. Particularly protected
a thicker passivating corrosion layer which are indigenous peoples (IP), who hold
suggests faster corrosion rates at location B. certificates of ancestral domain titles (CADT)
on lands inside the planned mining
*Co-author: Manolo G. Mena concession. Despite such provisions of PMA,
however, audits conducted by the
RINLEE BUTCH M. CERVERA Department of Environment and Natural
Cleantech Global Renewable Inc. Professorial Resources (DENR) in 2016 found that several
Chair in Renewable Energy mine areas were lacking proper
environmental plans, with denuded forests
“Morphology and Structure of Ni/ and silted rivers as evidence of such
Zr0.84Sc0.16O1.92 Electrode Material uncontrolled degradation (De Vera-Ruiz 2017).
Synthesized via Glycine-Nitrate Combustion The partner-agencies in the implementation of
Method for Solid Oxide Electrochemical Cell” the law, such as the National Commission on
Indigenous Peoples (NCIP), are also reported
* Paper published in Applied Sciences. 13 to be suffering from institutional issues that
January 2019. Appl. Sci. 2019, 9, 264; affect the performance of their role in the
doi:10.3390/app9020264. mining sector. This study looks at the causes of
such problems and reviews the legal
*Co-author: Renz Marion Garcia framework to come up with policy
recommendation to address the issues. In
UP COLLEGE OF ENGINEERING TECHNICAL BULLETIN 2019 particular, it reviews related laws and
department and executive orders and

55

presents the results of the key informant (FTIR) spectroscopy, swelling studies, in-vitro
interviews (KII) involving representatives from biodegradation, and rheological
the Chamber of Mines of the Philippines and measurements. FTIR spectra showed that the
the public sector, specifically those from DENR synthesized hydrogels contain a semi-
and the local government. interpenetrating network of polymers, with
interactions primarily due to physical
The study shows that circumvention of crosslinking. Furthermore, it was established
permits, delays of issuance of NCIP that the addition of cellulose has resulted to
documents and other tasks related to significant changes in hydrogel properties.
government functions have been identified as The swelling of the hydrogel increased with
the cause of such problems. In view of this, addition of cellulose while the degradation
proper planning and inter-agency rate slows down. Results of rheological tests
communication should be well crafted before have shown that the material exhibits shear
any Department order issuances are released. thinning and viscoelasticity wherein it
These orders are also more beneficial to all behaves more solid-like. However, high
concerned if there is no leeway for the cellulose amounts caused clogging while
regional offices to put in their own printing, thus limiting the amount of
interpretation of the regulations. reinforcement that could be added. The
results of this study have shown the potential
*The paper was published in this website: of a composite cellulose-chitosan hydrogel to
https://www.pids.gov.ph/publications/6835. serve as bioink specifically for 3D printing of
articular cartilage.
JOHN KENNETH A. CRUZ
Crisostomo A. Ortigas Professorial Chair *Co-authors: Gerardo Martin Quindoza III,
Patrick Aldwin Castillo, and Jill Manapat
“Synthesis and Characterization of Cellulose
Reinforced Chitosan Hydrogel as Potential MARK JEFFRY D. DE LEON
Bioink for 3d Printed Articular Cartilage Benguet Management Corporation
Scaffolds”* Professorial Chair

Abstract: 3D printing for tissue engineering “Development of a Cold Atmospheric
applications is becoming prominent Pressure Plasma Jet Driven by a 60 Hz Neon
nowadays. It allows the construction of Transformer”*
patient-specific and cost-effective tissue
scaffolds with easiness. These scaffolds are Abstract: In this study, a cold atmospheric
implanted to a target area, such as a knee pressure plasma jet (CAPPJ) using a neon
articular cartilage, to allow regeneration of transformer as its power source was
the tissue and repair of its defects. What developed and its electrical, thermal, and
remains to be the biggest hurdle is the optical properties were investigated. The
selection of the proper ink material or bioink. device developed was a bare electrode arc
Chitosan is an established material that may discharge-based system powered by a 15 KV,
be utilized for tissue scaffolds and it has the 30 mA, 60 Hz neon transformer. This was then
rheological properties that makes it printable; connected to a variable autotransformer to
however, its main limitation would be its control the power delivered unto the plasma.
strength. This study aims to synthesize a The nozzle of the device was made out of
chitosan hydrogel reinforced with cellulose polytetrafluoroethylene and the electrodes
and to assess its potential as bioink in 3D were made of stainless steel bolts. The process
printing of engineered articular cartilage. The gases used were nitrogen and air. The flow of
cellulose reinforced chitosan hydrogels were the gas was controlled by a flow meter and
synthesized via thermoresponsive sol-gel was fed through the nozzle, passing through a
method. The synthesized hydrogels were 1 mm gap between the electrodes and out
characterized using Fourier transform infrared of a 1 mm diameter hole where the plasma

56 UP COLLEGE OF ENGINEERING TECHNICAL BULLETIN 2019

jet is ejected. The developed device was resistance measurements. Results indicated
able to produce a 7 mm long air plasma that the application of pulsed current and
plume and 24 mm long nitrogen plume that additives reduced the grain size of deposits.
had a temperature of less than 60◦C 5 mm This grain refinement improved yield and
from the nozzle. The discharge voltage for the tensile strength, but reduced the ductility and
plasma jet was found to be around 1.5 KV conductivity of deposits. The optimum
RMS and the waveform changed from additive concentration for the EnFACE
sinusoidal to a square waveform with lower electrolyte was 33% when using PC plating.
amplitude when the discharge was
produced. The optical emission spectra show *Co-author: Prof. Sudipta Roy
that the air plasma was composed of
nitrogen and oxygen excited species while LESLIE JOY L. DIAZ
the nitrogen plasma showed mostly nitrogen Integrated Microelectronics, Inc. (IMI)
species. This work was able to demonstrate Professorial Chair
the development of a CAPPJ system using a
low-frequency power source that can be “Synthesis of Montmorillonite Nanoclay
used to treat different surfaces that may find Reinforced Chitin-cellulose Nanocomposite
practical industrial applications. Film”*

*Co-author: Magdaleno Vasquez Jr.

EDEN MAY B. DELA PEÑA Abstract: Montmorillonite (MMT) nanoclay
Antonio and Lourdes Tanchuling Mining reinforced chitin-cellulose nanocomposite is a
Engineering Centennial Professorial Chair biodegradable polymer that has potential as
a food packaging material. In this study, it
“The Properties of Pulse-Plated Copper was synthesized using 1 and 5 wt% MMT (1NC
Produced from Low Metal Ion Concentration and 5NC) via solution casting. Good
Electrolyte”* miscibility of chitin and cellulose was
interpreted by the presence of cylindrical
Abstract: The use of pulsed current (PC) is particles revealed in the SEM image, and the
XRD peak at ~19° and shoulder at ~23°. Peaks
known to improve the grain structure and were also observed at 2.62 and 2.27° for 1NC
and 5NC, respectively, that corresponded to
properties of electroplated copper. A 16.87 and 19.47 Å interlayer spacings, both of
which were higher than that of pristine MMT
promising mask-less electroplating process which is 12.57 Å. This suggested that chitin-
cellulose penetrated MMT and that 5NC had
called EnFACE uses a plating electrolyte that a lower degree of intercalates, which was
confirmed by EDX mapping. This better MMT
is acid-free and has low copper salt dispersion was speculated to be due to the
nematic state of 5NC gel. With molecules
concentration. However, the effect of pulsed sliding off easily in the gel, polymer
penetration in the interlayer spacing was
current on the deposits plated using the easier. This was verified by its lower apparent
viscosity. Finally, this better MMT dispersion
EnFACE electrolyte still needs to be resulted to a good stress transfer and, maybe,
introduced a more torturous crack path for
understood. This work examines the properties 5NC. These improved its toughness (2.22 J/
mm3) and Young's modulus (6. 25 GPa).
of copper deposited by PC plating using the

EnFACE electrolyte with commercial

additives. Twenty-five micron copper films

were plated on stainless steel substrates. The

additives used were Copper Gleam A,

Copper Gleam B, and Cl-. The electrolytes

tested contained different concentrations of

additives ranging from 17% to 200% of supplier

recommended concentrations. The

morphology of deposits was characterised *Co-authors: Tiffany Louise Lao, Lance Tristan
Pengson, Jordan Placido.
using electron-backscattered diffraction

(EBSD) and x-ray diffraction (XRD). Deposited

films were also subjected to ductility and Published in IOP Conf. Series: Materials

UP COLLEGE OF ENGINEERING TECHNICAL BULLETIN 2019 57

Science and Engineering. 540 (2019) 012010. possibility for large scale production and an
doi:10.1088/1757-899X/540/1/0120 opportunity to modify and tune the surface
functionalities, sizes and photoluminescent
RICHARD DV.ESPIRITU characteristics of the CQDs by
Willy Lim Bon Teck Engineering Mining biofunctionalization and conjugation
Centennial PC techniques.

“Density Functional Theory Study on the *Co-authors: Christian James Emman and
Degradation of Fuel Cell Anion Exchange Gerald Mari Quiachon
Membranes via Removal of Vinylbenzyl
Quaternary Ammonium Head Group”* JILL Z. MANAPAT
Pedro Dumol Professorial Chair
Paper published in Polymer Degradation and
Stability. July 2019. Copyright © 2018 Elsevier “Redefining Philippine Higher Education
B.V. through Humanitarian Engineering
Entrepreneurship and Design (HEED)”*
*Co-authors: John Lester Tan, Len Herald Lim,
and Susan Arco Abstract: Today‟s rapidly changing society

EDUARDO R. MAGDALUYO JR. demands innovative ways of educating
Dean Oscar P. Baguio Professorial Chair
engineering and design students to create
“Formation of Carbon Quantum Dots from
Hydrothermal Treatment of Water Hyacinth sustainable social impact. As a response, the
(Eichhornia crassipes) ”
University of the Philippines Diliman (UPD)
Abstract: The carbon quantum dots derived
from biological sources showed much interest recently formed the Humanitarian
in biomedical applications due to their
biocompatibility. The water hyacinth Engineering, Entrepreneurship, and Design
(Eichhornia crassipes) biomass is a sustainable
resource, which has the potential to be (HEED) – a university-wide research and
utilized in diverse applications. This paper
reports for the first time the synthesis of carbon design group that aims to engage faculty,
quantum dots (CQDs) from water hyacinth as
a new carbon source via facile one-pot students, and relevant stakeholders in a
hydrothermal route in acetic acid. The CQDs
are monodispersed and quasispherical in collaborative effort to effectively bring
shape, with blue emission and quantum yield
of 5.24%. Selective diffraction pattern technological solutions to underserved
confirmed the crystallinity of the CQDs while
the infrared spectra showed the presence of communities. Pioneered by the College of
aromatic carbon core and surface
functionalities of hydroxyl and carbonyl Engineering (COE) and the College of Fine
groups. The CQDs were then tested for
cellular imaging with freshly grown Allium Arts (CFA), the group‟s pilot activity is HEED
cepa and E. coli cells, showing visible cell
walls and nucleus compared to using 2017 – the first Humanitarian Engineering
reference dye. Cytotoxicity results indicate
the biocompatibility of the CQDs for the living Symposium and Workshop Series held last July
cells. More significantly, this method offers a
2017. The event served as an introduction to
58
the field of humanitarian engineering for

around 100 participants, most of whom were

faculty and students from the COE and CFA‟s

Industrial Design program. A few months after

HEED 2017, the group partnered with the UP

College of Social Work and Community

Development (CSWCD) to tap their

experience in community engagements, thus

ensuring that a proper and sustainable

approach is employed when reaching out to

underserved communities. This paper

discusses in detail how radical collaborations

between three colleges that were once

“worlds apart” was established, its current

projects and how in envisions to duplicate the

HEED model to higher education institutions

throughout the Philippines.

UP COLLEGE OF ENGINEERING TECHNICAL BULLETIN 2019

*Co-author: Fortunato B. de la Peña Jr. Abstract: The leaching response of chromite
concentrate in hydrochloric acid solution was
JOY MARISOL F. MANIAUL studied. Results show a 15 to 30-fold
SR Metals Professorial Chair enhancement of iron over chromium
extraction suggesting the feasibility of
“Recovery of Gold using Aluminum in chemical beneficiation as a means of
Chloride Solution”* improving the value of this material which is
normally discarded. At 85 oC, % chromium
Abstract: Chlorination is an alternative extraction was 0.469% while the extraction of
method for cyanidation in the gold and silver iron is 8.084% after 20 hours of leaching in 10N
process extraction that makes use of chlorine- HCl solution. The dissolution rates of
chloride solutions to render the metal chromium and iron are both thermally
aqueous. It is also used to dissolve gold in activate, with temperature having a greater
precious metal refineries. One reduction effect on chromium extraction as compared
technique used for gold recovery in aqueous to iron. This suggests the use of moderate
solution is the cementation process. This study temperatures in the chemical beneficiation of
evaluated the recovery of gold in a chloride chromite.
solution using aluminum as a cementation
agent. The effect of pH, temperature and The dissolution kinetics of iron does not follow
stirring rate under nitrogen atmosphere was the Shrinking Core Model, as evidenced by
studied using powder cementation. Results the “lack of fit” to the shrinking core model
showed that maximum recovery and reaction equations. Further, the initial leaching rate is
rate is favored at pH 2, at 50 degrees Celsius not a function of particle size or surface area.
and at 400 rpm stirring rate at 61.48% Energy Dispersive Spectrometric analysis of
recovery and reaction rate constant of 0.0063 the cross section of partially leached particles
s-1. The factorial experiment shows that the did not show the presence of a product layer
main effects pH and stirring rate and their two which is typical of the Shrinking Core Model.
-way interaction with temperature are found
to be significant. Recovery of aluminum is The extraction of iron was found to be
found to increase at increasing pH and logarithmic with time. This was explained in
increasing stirring rate. The recovery is greater terms of the strain-relief model involving a
at a faster rotation speed due to the particles linear increase in the leaching activation
being more dispersed in the solution while energy as extraction proceeds. X-ray
higher pH is found favorable due to the Diffraction Analysis prior and after leaching
reactivity of aluminum. Interaction effect showed a shift in the 2-theta peaks which
shows that the effect of stirring rate is more could be indicative of a reduction in the
observable at elevated temperatures while internal stresses in the chromite spinel
the temperature is shown to have more effect structure.
at pH 2. The SEM photomicrographs show
dendritic with fine crystallite gold deposits. HERMAN D. MENDOZA
The porous nature of the deposit enables the Philex Mining Corp. UP Centennial Professorial
cementation reaction to proceed. Chair-2

*Co-authors: Manolo G. Mena and Herman “Hetero-Coagulation of Finely Dispersed
D. Mendoza Particles in an Aqueous Suspension Using the
Seeding Mechanism"*
MANOLO G. MENA
Don Benito Yao MetE Centennial Prof. Chair An investigation of the seeding mechanism
using heterocoagulation and the Derjaguin –
“Dissolution Kinetics of Chromite in Landau – Verwey – Overbeek (DLVO) theory
Hydrochloric Acid Solutions” of two pure minerals is the objective of this
study. The seed was silica with modal
UP COLLEGE OF ENGINEERING TECHNICAL BULLETIN 2019
59

diameters of 4.529 µm (fine particles) and instruments, in order to guide individuals into
5.216 µm (coarse particles) and the test identifying gold. Applicability, limitations, and
powder was hematite with a modal diameter advantages and disadvantages of these
of 0.883 µm. Parameters included variations in methods are also discussed.
the concentration and particle size of silica.
Both particles were first subjected to size CANDY C. MERCADO
determination and settling tests via Stoke‟s PHINMA Foundation Professorial Chair
Law. The silica-hematite system was then
suspended in 0.001 M KNO3 electrolyte “Extraction and Purification of Anthocyanin
solutions where pH was adjusted. Afterward, from Antidesma bunius for Visible
the suspension was agitated and was allowed Photocatalysis”
to settle at different time intervals while
obtaining turbidity readings. Results through Abstract: Anthocyanin is a group of pigments
settling time and turbidity vs. pH graphs
indicate that maximum heterocoagulation that have a potential to be used for
occurs from pH 2 to 5 while minimum
heterocoagulation occurs from pH 6 to 7. At photocatalysis and other visible light
these pH levels the zeta potentials of silica
and hematite are negative and positive, absorption. Anthocyanin can be extracted
respectively. On the contrary, repulsive forces
dominate the system from pH 8 to 11 due to from Antidesma bunius using 70% acidified
the particles‟ negative zeta potentials.
Furthermore, the attachment of hematite to ethanol for 2 hr. Purification can be done
silica increases when the parameters become
larger thereby increasing the effectivity of using 1:1 ratio of the chloroform and the
heterocoagulation at acidic to neutral pH
levels. crude extract. The extraction time has the

*Co-author: Luisa Angeli R. Ciriaco most significant effect on the extraction

TERENCE LUCERO F. MENOR followed by the acid and the extracting
Domingo Toledo Professorial Chair
solvent concentration. The adsorption
“Who Wants to be a Millionaire? An Overview
of the Gold Detection Methods for God or mechanism of the anthocyanin onto TiO2
Gold-containing Articles”
substrate is found to fit the Langmuir Isotherm
Abstract: Tales of hidden treasures have
circulated in the Philippines since the 19th model which implies that the mechanism is
century. Majority of these tales are about gold
jewelries and artifacts. Successful stories of monolayer. Anthocyanin is more stable in low
gold hunt and surging price of gold in the
past several years have attracted even the pH compared to higher pH but degrades 10%
ordinary people to hunt and invest in gold in
the hopes to have instant fortune. Because of more in low pH when exposed to sunlight. The
the allure of gold, a lot have been tricked into
buying gold articles which turn out to be fake. redox behaviour is found to be similar to that
In some cases, the search for gold becomes
very costly making the activity worthless. This of peonidin-3-O-glucoside with two anodic
paper aims to provide an overview of gold
detection methods, ranging from the simplest peaks occurring at 377 mV and 900 mV.
physical measurements to complex analytical
Peonidin-3-O-glucoside is one of the major
60
pigments in sweet cherry fruit trees. This

confirms that the extracted solution contains

anthocyanin pigments. Therefore,

anthocyanins can be used as a natural

colorant, and for antioxidant, photocatalysis

and any visible light absorber applications

*Co-author: Ma. Eden Dorothy Q. Nonog

IVY ANN C. RAZONADO
Semirara Mining & Power Corporation
Professorial Chair (2)

“Fabrication Parameters Affecting Thermal
Conductivity of Polymer-based Thermal
Interface Material”*

Abstract: With our recent technology, goals of
producing gadgets are now more focused on

UP COLLEGE OF ENGINEERING TECHNICAL BULLETIN 2019

efficiency and miniaturization. However, with KATHERINA LOIS M. TAACA
these requirements come a greater Jardiolin Family Professorial Chair 1
challenge on the thermal management in the
chip level for heat dissipation. Semiconductor “Impregnation of Silver in Zeolite-Chitosan
industries addressed this challenge with the Composite: Thermal Stability and Sterility”*
use of thermal interface materials by which
polymer-clay nanocomposites have already Abstract: The solvent-casting method was
been researched. In this study, the aim was to used to synthesize a silver-zeolite-chitosan
obtain a satisfactory thermal conductivity at (AgZ-Ch) composite. Characterization
a lower addition of nanoclay by modifying techniques such as X-ray diffraction (XRD),
the microstructure in the polymer-clay ultraviolet-visible (UV-Vis) spectroscopy,
nanocomposite that may be induced by the optical emission spectroscopy (OES),
different methods of dispersion. Solution thermogravimetric analysis (TGA), and
intercalation method was employed in the differential thermogravimetry (DTG) were
preparation of nanocomposites at different used to investigate the different properties of
filler loadings of nanoclay. Organomodified the composite before and after plasma
montmorillonite (MMT) was dispersed in treatment. XRD pattern showed that majority
unsaturated polyester (UP) polymer matrix via of the phase composition of the Philippine
high frequency ultrasonication under different natural zeolite is mostly composed of Na-
parametric conditions (filler loading, pulse clinoptilolite with trace amounts of mordenite,
rate, power and sonication time) and via two feldspar, and quartz. UV-Vis and OES analyses
methods of casting, mold casting and tape confirmed the presence of Ag and zeolite on
casting. Results from the different parametric the chitosan matrix where a decrease in the
settings showed that the sample with the transmittance peak at 290 nm and the
highest thermal conductivity coefficient of emission spectra of the discharge showed the
2.873 W/m-K was obtained from the polymer presence of Ag I, Al I and Si I peaks at 705-852
nanocomposite with 5vol% filler loading and nm were observed, respectively. TGA and
dispersed at sonication parameters of 80% DTG curves revealed the thermal stability of
pulse rate, 50% power and 15 minutes the natural zeolites after ion-exchange and
sonication time. Furthermore, results also after its incorporation in the chitosan matrix
showed a slight increase in the thermal where the onset of degradation was
conductivity coefficient of the tape-casted observed to be more than the human body
samples at 2.993 W/m-K compared to the temperature of around 37°C. Bacterial count
mold-casted samples at 2.873 W/m-K. showed minimal growth of colonies to all
Transmission electron microscopy (TEM) and x- samples whether pristine or plasma-treated.
ray diffraction (XRD) exhibited dispersed This implies that the surface of the composites
microstructure and polymer intercalation of does not influence bacterial habitation. With
~16% increase in d-spacing of clay for mold- these results, it is observed that the fabricated
casted samples and with a ~20% increase in d composites have met the minimum
-spacing of clay for tape-casted samples. requirement for biomedical application such
With these microstructure modifications, the as thermal stability with respect to average
slight increase in the thermal conductivity human body temperature and bacteria-free.
coefficient of the tape-casted samples may
be attributed to the shear force employed by *Co-authors: E.M. Olegario and M.R. Vasquez
the tape casting technique. These findings Jr.
therefore suggested that improved filler
dispersion and better homogeniety of the 61
nanoclay fillers in the polymer matrix are
factors that are strongly influential to the heat
dissipation in nanocomposite materials.

*Co-authors: Emee Grace T. Suarnaba,
Lawrence V. Madriaga and Leslie Joy L. Diaz

UP COLLEGE OF ENGINEERING TECHNICAL BULLETIN 2019

MAGDALENO R. VASQUEZ JR.
Jardiolin Family Professorial Chair 1
“Plasma-
functionalizedexfoliatedmultilayeredgraphen
eascement reinforcement”*
Published in Composites Part B: Engineering.
Volume 160. 1 March 2019. pp.
573-585. https://doi.org/10.1016/
j.compositesb.2018.12.055. © 2018 Elsevier Ltd.
*Co-author: Ma. Shanlene D.C. Dela Vega

62 UP COLLEGE OF ENGINEERING TECHNICAL BULLETIN 2019

UP COLLEGE OF ENGINEERING TECHNICAL BULLETIN 2019 63

64 UP COLLEGE OF ENGINEERING TECHNICAL BULLETIN 2019