Engineering Commons^™

Effects Of Process Parameter Variation On The Surface Roughness Of Polylactic Acid (Pla) Materials Using Design Of Experiments (Doe), C. Burke, A. Dalal, A. Abukhalaf, Rafiqul Noorani

Mechanical Engineering Faculty Works

3D Printing (3DP) is an additive manufacturing technology used to rapidly build parts that are designed using 3D modeling software. 3DP builds a part by adding one layer of the working material at a time until the process is complete. One main concern with 3D printed samples is the high levels of surface roughness, which can result in the rejection of parts by many precision manufacturing companies. The objective of this research is to use the Design of Experiment (DOE) to analyze which factors influence the surface roughness of the part built from a 3D printer. In this research, a …

Three-Dimensional (3d) Reconstruction Of Computed Tomography (Ct) Abdominal Images Using Visualization Toolkit (Vtk), Mat Saad Afifah Husna

Student Works (2020-2029)

A computerized tomography (CT) or computerized axial tomography (CAT) scan combines data from several X-raysito produce a detailed image of structures inside the body. CT scans produce 2D of a “slice” or section of the abdomen but the data can also be used to construct 3-dimensional images. However, CT scan unable to accurately represent the internal structure of soft tissues and soft-tissue lesions. Therefore, using the program in Visualization Tool Kit (VTK) is needed to construct a much more clearer 3D image. To reconstruct 3D images from 2D images of a “slice” or section of abdomen which will be resulting …

Feasibility Study On Concentrated Solar Power Plants In Malaysia, De Jen Choy

Student Works (2020-2029)

The rapidly growing economy and population in Southeast Asia has elevated the need for affordable, secured, sustainable and environmentally friendly energy sources. One such energy source is solar energy which is a suitable energy source for most Southeast Asian countries which are within the Sun Belt region. This study performs a performance and financial analysis on concentrated solar power (CSP) technologies, specifically the solar power tower (SPT) in the Malaysian environment through the use of simulation software. The significance of the study lies in the fact that limited research has been done on CSP technologies in Malaysia and the study …

Analysis Of One Way Valve Mechanism For Wings Of A Flapping Drone, Xinchen Deng

Student Works (2020-2029)

The flapping drone is one type of MAVs which is defined as a miniature unmanned aerial vehicle that is inspired by flying birds and insects. Flapping wings can make a perfect combination of thrust and lift by flapping up and down with full usage of unsteady air. The flapping drone has the advantages of high maneuverability and a special lift generation mechanism. Compared with rotary-wing or fixed-wing MAV, it is smaller, lighter, and has higher flight performance. It can quickly change the flight direction and flight speed by control the flapping frequency and it is the only flight mode that …

Investigations Of Air-Water Multiphase Flow In Tubes: Computational Fluid Dynamics, Wei Hong Goo

Student Works (2020-2029)

Mixing is a very crucial process in many industries, such as food processing industry, minerals processing industry, petrochemicals and refining industry, pulp and paper industry, polymer industry, pharmaceuticals industry and many more. There are different types of mixing, such as liquid-gas mixing, liquid-liquid mixing, solid-liquid mixing and many more. The definition of multiphase flow is the simultaneous flow of materials with multiple thermodynamic phases. A lot of process industries require multiphase flows during operation. Bubbly flow is defined as the flow of liquids that contains dispersed gas bubbles. One of the main applications of multiphases flows and bubbly flows is …

Thermodynamic Analysis And Optimization Of Organic Rankine Cycles Using 1-Butylpyridinium Tetrafluoroborate As A Geothermal Fluid, Kazemi Shabnam

Student Works (2020-2029)

Organic Rankine cycle (ORC) is a promising technology for electricity generation by utilizing heat sources at low to moderate temperature that ranges between 80-350° C. In the present work, an ionic liquid (1-butylpyridinium tetrafluoroborate, C9H14NBF4), a known green chemical and non-volatile compound with good thermal and chemical stability, significant heat capacity, low vapor pressure and a wide liquid temperature range (25 to 459 °C), is utilized as a geothermal fluid. Simulation and optimization were conducted for a basic organic Rankine cycle (basic ORC), a regenerative organic Rankine cycle (RORC) and a two-stage evaporative organic Rankine cycle (TSORC) by maximizing exergy …

Waste Cooking Oil Classification Using Artificial Intelligence Technology, Kar Sin Lau

Student Works (2020-2029)

Palm oil – one of the most common edible oil consumed in Malaysia. It is because Malaysia is one of the countries which supply palm oil to the global market and it is cheap to obtain for the consumer in Malaysia. Most of the Malaysian consume it via food preparation such as deep-frying and cooking. However, due to widely available for Malaysians, consumers also lacking awareness in dealing after using the edible oil. Most of the household consumers discard excess waste cooking oil (WCO) into sewage and with courtesy, some of them stored them in containers and sell to NGOs. …

Mental Workload Investigation Among Employees In A Selected Oil And Gas Company, C. Moosom Christyne Surindai

Student Works (2020-2029)

In recent years, there has been a substantial amount of studies being conducted in mental workload and mental health but there is little research conducted in the Malaysian context especially in the oil and gas field. This gives rise to the need for researching the level of mental workload and mental health problems that will help the stakeholders to protect the wellbeing of their employees. This study aims to investigate the mental workload and level of depression, anxiety and stress scale of employees in a selected oil and gas company by using CarMen-Q and DASS-21 mental health assessment tools, finds …

Fault Location In Distribution System Based On Voltage Sag Analysis, Ahmad Muhamad Firdaus

Student Works (2020-2029)

Fault in the distribution system is something that cannot be avoided. It is a recurring event that occurs due to various factors such as natural occurrence, mechanism failure, or human error. All this contributes to the phenomenon that will affect the stability of the system and result in the loss of power to the consumers. However, such a fault is something that happens unexpectedly, and it is difficult to be eliminated. Therefore, various research work has been done over the years to overcome the problem. All research is done to find the most effective method of finding the fault location …

Study Of Heat Transfer And Friction Loss Of Nanofluid Suspension Flow In Circular Pipe Heat Exchanger, Ramadas Sandru

Student Works (2020-2029)

This stated experiment focused on the study of convective heat transfer and friction loss in a circular flow passage for Graphene oxide-based nanofluids which are consist of Graphene Oxide/Distilled water with their different wt. % concentrations. These GO/DW based nanofluids where been prepared by using a facile two-step method, while the GO particles were synthesized by a modified hummer method. Four different (0.025, 0.05, 0.075, and 0.1 wt. %) were produced by dispersing graphene particles in distilled water under high probe sonication. The GO/DW based nanofluids flowing in a horizontal shell and tube heat exchanger counter flow under turbulent flow …

Comparison Of Pressure-Assist Silver Sintering To Tin Silver Solder Alloy As Die Attach Material In High Power Semiconductor, Tolentino Erik Nino

Student Works (2020-2029)

The research is focused on pressure-assisted silver sintering material that is compared to tin silver solder alloy paste as used in power electronics. Material characterization, electrical tests, and reliability tests were conducted in the experiment. After drying process, it was observed that the Ag sintering paste height was reduced to approximately 40 percent. Die attach shear test showed that the average reading is about from 200 to 600 grams which are already enough to hold the dice before proceeding to the pressure sintering process. X-ray revealed that the void percent for SnAg paste sample is about 1.5 percent while pressure-assist …

Development Of Plasticized Methylcellulosepotato Starch Blend Based Polymer Electrolytes For Protonic Cell And Supercapacitor Applications, Hamsan Muhamad Hafiz

Student Works (2020-2029)

In the current work, the preparation of the polymer electrolyte (PE) systems consists of methylcellulose-potato starch polymer matrix, ammonium nitrate (NH4NO3) as ionic source and glycerol as plasticizer are done by solution cast technique. X-ray diffraction (XRD) has shown that blend with 60 wt.% methylcellulose and 40 wt.% potato starch possesses the lowest degree of crystallinity. The possible interactions within the PE are verified using Fourier transform infrared (FTIR) spectroscopy. As the concentration of NH4NO3 is at 30 wt.%, the conductivity is optimized up to (4.37 ± 0.16) × 10-5 S cm-1 and then maximized to (1.26 ± 0.1) × …

Investigation Of Complex Refractive Index Of Grad Phene Oxide Using Polarisation Response Of Graphene Oxide-Coated Planarizeoptical Waveguide, Soon Xin Gan

Student Works (2020-2029)

Since a single atomic layer of carbon, also as known as graphene is being successfully exfoliated from 3D graphite, intense research on graphene and its derivative begins. Among them, graphene oxide (GO) is considered one of the most prominent candidates in the category of graphene derivatives for the application of electronic, optoelectronic and photonics. However, although GO has been applied in many applications like saturable absorbers of Q-switch laser and optical limiters for eye protection, its intrinsic optical properties especially complex refractive index reported so far still has a large deviation. Also, most of the optical characterization research on GO …

Development Of Bragg Fiber Sensor For Corrosion Detection, Cai Hui Tan

Student Works (2020-2029)

Steel corrosion has posed one of the major structural defects in the civil society today. Conventional methods for corrosion monitoring involve high maintenance cost and destructive methods with low accuracy. Recently, Fiber Bragg gratings (FBG) sensor with its high sensitivity in measuring strain and temperature have been widely studied and used in structural health monitoring (SHM). A non-destructive corrosion detection approach based on FBG sensors was developed and tested to monitor corrosion in this research work. The principle of FBG sensing is based on Bragg wavelength shifts that from the corrosion process that induced strain on the FBG due to …

3-Dimensional Carbon Micro-Electro Mechanical System (Mems) Electrode For Potential Dielectrophoretic Hepatic Cell Patterning Application, Wan Yahya Wan Nurlina

Student Works (2020-2029)

The maintenance of liver tissue unique pattern remains a great challenge in the generation of functional engineered liver tissue in vitro. This thesis presents a carbon dielectrophoresis (DEP) based cell patterning for generating hepatic cell constructs, mimicking biological hepatic lobule. A new design of electrode named interdigitated radiating-strips electrode (IRSE) was simulated and optimized using COMSOL Multiphysics 4.2a. The simulation result proved that IRSE is capable to provide uniform distribution of electric field for generating three-dimensional (3D) DEP force. The use of carbon electrodes has been an alternative to traditional metal electrodes and insulator structures for DEP applications since more …

Organic Materials As Saturable Absorber For Pulse Generation At Telecommunication Window, Mohammed Hussein Sameer Salam M.H.

Student Works (2020-2029)

This thesis demonstrates several types of fiber lasers based on newly developed organic materials as saturable absorbers (SAs). We used these SAs in all-fiber based erbium-doped fiber laser (EDFL) ring cavity to produce Q-switched and mode-locked pulses at telecommunication window, at ~ 1560 nm. Three different organic materials were used in this thesis: Bis[2-(4,6-difluorophenyl)pyridinato-C2 ,N](picolinato)iridium(III) (FIrpic), bis(8-hydroxyquinoline)zinc (Znq2) and Tris(8-hydroxyquinoline)aluminum (Alq3). Finding new materials is still one of the defining characteristics of nonlinear optics field, as the rapid development of SAs has provided several new opportunities for nonlinear optics. Throughout this work, organic material showed a very interesting performance in …

Optimization Of Bioethanol Production, Engine Performance And Exhaust Emissions From Manihot Glaziovii And Sweet Sorghum In A Spark Ignition Engine, Sebayang Abdi Hanra

Student Works (2020-2029)

The ever-increasing fossil fuel consumption over the years is attributable to economic and population growth, which in turn, increases greenhouse gas emissions. Bioethanol is one of the promising solutions to address the depletion of fossil fuels as well as environmental problems. Manihot glaziovii tubers and sweet sorghum grains are inedible feedstocks that can be used for bioethanol production. The carbohydrate content (70%) of these biomasses makes them suitable as feedstocks for bioethanol production. In this study, enzymatic hydrolysis (liquefaction and saccharification) was used to obtain the reduction of sugars. The enzymes α-amylase from Bacillus licheniformis Type XII-A and amyloglucosidase from …

Enhancement Of Graphene Biocompatibility As A Potential Nano-Carrier For Drug Delivery Applications Using Natural Deep Eutectic Solvent, Zainal Abidin Mohamad Hamdi

Student Works (2020-2029)

Graphene has attracted massive interest in numerous biomedical applications such as anti-cancer therapy, drug delivery, bio-imaging and gene delivery. Therefore, it is important to ensure that graphene is nontoxic, and that its cellular biological behavior is safe and biocompatible. Herein, a new route was used to enhance the biocompatibility of graphene as a nano-carrier for potential drug delivery applications, using different compositions of natural deep eutectic solvents (DESs) as functionalizing agents, owing to their capability to introduce various functional groups and surface modifications. To meet this end, eight different combinations of binary and ternary DESs were synthesized using choline chloride …

Emergency Department Systems Engineering: Modelling And Event Simulation, O Alharethi Salman Zayed

Student Works (2020-2029)

Emergency department systems are meant to ensure the timely delivery for essential healthcare services through complex systems. (ED) offers various services and have several components in its parts. Examined long previous research on system engineering and quality of healthcare resulting on these are influenced by operational management. Real time data are very helpful for decision making for any systems. Patient output feedback and satisfaction can be ensured with engineered management. EDs have become evident particularly in current scenario when the world is in the grip of the deadly COVID-19. All this implies that analysis is significant for improvement of services …

Signal Processing Combined With Machine Learning For Biomedical Applications, Md Shakhawat Hossain

Theses and Dissertations

The Master’s thesis is comprised of four projects in the realm of machine learning and signal processing. The abstract of the thesis is divided into four parts and presented as follows,

Abstract 1: A Kullback-Leibler Divergence-Based Predictor for Inter-Subject Associative BCI.

Inherent inter-subject variability in sensorimotor brain dynamics hinders the transferability of brain-computer interface (BCI) model parameters across subjects. An individual training session is essential for effective BCI control to compensate for variability. We report a Kullback-Leibler Divergence (KLD)-based predictor for inter-subject associative BCI. An online dataset comprising left/right hand, both feet, and tongue motor imagery tasks was used to …

Cooperative Target Tracking In Balanced Circular And Elliptical Formations, Lili Ma, Naira Hovakimyan

Publications and Research

This paper extends our earlier results on cooperative target tracking in cyclic pursuit using a group of mobile robots by further prescribing the formation radius and achieving an elliptical formation pattern. Prescribing the formation radius of a balanced circular formation is achieved by adjusting a parameter in the existing control input to each robot. The new elliptical formation pattern is obtained via a transformation matrix. Both single-integrator and double-integrator robot models are considered. The effectiveness of the proposed schemes is demonstrated by simulation examples.

Detection Of Standing And Sitting Variations Based On In-Socket Piezoelectric Sensors For Transfemoral Amputees, Alnusairi Tawfik Yahya

Student Works (2020-2029)

A transfemoral prosthesis is required to assist amputees to perform activities of daily living (ADL). The purely mechanical or passive prosthesis has some drawbacks such as consumption of high metabolic energy and limitations in mimicking normal dynamics and kinematics of gait pattern. In contrast, the active prosthesis offers better performance and consumes less metabolic energy. However, recent active prosthesis uses surface electromyography as its sensory system which requires massive preparation work, causes sores to the patient by its electrodes and requires a lot of computation to extract meaningful features. This thesis focuses on developing signal conditioning circuitry to classify six …

Understanding The Laser Powder Bed Fusion Of Alsi10mg Alloy, Holden Hyer, Le Zhou, Sharon Park, Guilherme Gottsfritz, George Benson, Bjorn Tolentino, Brandon Mcwilliams, Kyu Cho, Yongho Sohn

Mechanical Engineering Faculty Research and Publications

We examine the microstructural characteristics of LPBF AlSi10Mg produced by using a wide range of LPBF processing parameters with independently varied laser power, hatch spacing, scan speed, slice thickness, and the normalized energy density. The lower energy density produced lack of fusion flaws from residual interparticle spacing, while the higher energy density produced spherical pores from trapped gas. The highest density (> 99%) samples were produced by using an energy density of 32 to 54 J/mm³. Within this energy density range, use of smaller slice thicknesses increased the processing window that would produce dense AlSi10Mg samples. A cellular …

Low-Cost Reaction Wheel Design For Cubesat Applications, Nicholas J. Bonafede Jr.

Master's Theses

As science instruments on CubeSats become more sensitive to the attitude of the spacecraft, better methods must be employed to provide the accuracy needed to complete the planned mission. While systems that provide the accuracy required are available commercially, these solutions are not cost-effective, do not allow the design to be tailored to a specific mission, and most importantly, do not give students hand-on experience with attitude control actuators. This thesis documents the design, modeling, and simulation of a low-cost, student-fabricated, reaction wheel system for use in 3U CubeSat satellites. The entire design process for the development of this reaction …

Traffic Privacy Study On Internet Of Things – Smart Home Applications, Ayan Patel

Master's Theses

Internet of Things (IoT) devices have been widely adopted in many different applications in recent years, such as smart home applications. An adversary can capture the network traffic of IoT devices and analyze it to reveal user activities even if the traffic is encrypted. Therefore, traffic privacy is a major concern, especially in smart home applications. Traffic shaping can be used to obfuscate the traffic so that no meaningful predictions can be drawn through traffic analysis. Current traffic shaping methods have many tunable variables that are difficult to optimize to balance bandwidth overheads and latencies. In this thesis, we study …

Boost Converter Inductor Sizing Effects On The Performance Of Mppt Algorithms, Alan Nonaka

Master's Theses

With solar power and other renewables set to take over the market in the coming decades, maximum power point tracking will be essential to optimizing power output. One underserved topic of research is the effect of inductor current ripple on performance of Maximum Power Point Tracking (MPPT) algorithms. Many new topologies are focused on decreasing the ripple from PV source to increase efficiency and power output. However, not much has been done to show ripple degrading performance of MPPT algorithms. This study uses a boost converter topology to test the performance of constant duty cycle step Perturb and Observe (PO), …

Hydraulic Effects Of Perpendicular Water Approach Velocity On Meter Gate Flow Measurement, John M. Thorburn

Master's Theses

Accurate flow measurement is required to effectively manage water resources. California Senate Bill X7-7 (SB X7-7), legislates this need by requiring agricultural water providers serving areas greater than 25,000 acres to develop an Agricultural Water Management Plan (AWMP) and adopt pricing based at least partly on volumetric water deliveries (DWR, 2009). This study focused on two of the most common flow measurement/flow control devices used in California open channel water conveyance systems: the circular meter gate and the rectangular meter gate. Testing was conducted on three Armco-type (round gates over round discharge pipe) gates measuring 12”, 18”, and 24” and …

Pathfinding Interplanetary Bus Capability For The Cal Poly Cubesat Laboratory Through The Development Of A Phobos-Deimos Mission Concept, Alyssa M. Ralph

Master's Theses

With the rise of CubeSats and the demonstration of their many space applications, there is interest in interplanetary CubeSats to act for example as scientific investigations or communications relays. In line with the increasing demand for this class of small satellites, the Cal Poly CubeSat Lab (CPCL) seeks to develop a bus that could support an interplanetary science payload. To facilitate this, a mission concept to conduct science of the moons of Mars, Phobos and Deimos, is investigated by determining the mission needs for a CubeSat in a Phobos-Deimos cycler orbit through the development of a baseline design to meet …

Minimising Induced Drag With Weight Distribution, Lift Distribution, Wingspan, And Wing-Structure Weight, Warren F. Phillips, Douglas F. Hunsaker, Jeffrey D. Taylor

Mechanical and Aerospace Engineering Student Publications and Presentations

Because the wing-structure weight required to support the critical wing section bending moments is a function of wingspan, net weight, weight distribution, and lift distribution, there exists an optimum wingspan and wing-structure weight for any fixed net weight, weight distribution, and lift distribution, which minimises the induced drag in steady level flight. Analytic solutions for the optimum wingspan and wing-structure weight are presented for rectangular wings with four different sets of design constraints. These design constraints are fixed lift distribution and net weight combined with 1) fixed maximum stress and wing loading, 2) fixed maximum deflection and wing loading, 3) …

Improving Hardware Implementation Of Cryptographic Aes Algorithm And The Block Cipher Modes Of Operation, Chu-Wen Cheng

Theses and Dissertations

With ever increasing Internet traffic, more business and financial transactions are being conducted online. This is even more so during these days of COVID-19 pandemic when traditional businesses such as traditional face to face educational systems have gone online requiring huge amount of data being exchanged over Internet. Increase in the volume of data sent over the Internet has also increased the security vulnerabilities such as challenging the confidentiality of data being sent over the Internet. Due to sheer volume, all data will need to be effectively encrypted. Due to increase in the volume of data, it is also important …