Engineering Commons^™

Carrier Transport Engineering In Wide Bandgap Semiconductors For Photonic And Memory Device Applications, Ravi Teja Velpula

Dissertations

Wide bandgap (WBG) semiconductors play a crucial role in the current solid-state lighting technology. The AlGaN compound semiconductor is widely used for ultraviolet (UV) light-emitting diodes (LEDs), however, the efficiency of these LEDs is largely in a single-digit percentage range due to several factors. Until recently, AlInN alloy has been relatively unexplored, though it holds potential for light-emitters operating in the visible and UV regions. In this dissertation, the first axial AlInN core-shell nanowire UV LEDs operating in the UV-A and UV-B regions with an internal quantum efficiency (IQE) of 52% are demonstrated. Moreover, the light extraction efficiency of this …

Improving The Stimulation Selectivity In The Human Cochlea By Strategic Selection Of The Current Return Electrode, Ozan Cakmak

Dissertations

The hearing quality provided by cochlear implants are poorly predicted by computer simulations. A realistic cochlear anatomy is crucial for the accuracy of predictions. In this study, the standard multipolar stimulation paradigms are revisited and Rattay’s Activating Function is evaluated in a finite element model of a realistic cochlear geometry that is based on µ-CT images and a commercial lead. The stimulation thresholds across the cochlear fibers were investigated for monopolar, bipolar, tripolar, and a novel (distant) bipolar electrode configuration using an active compartmental nerve model based on Schwartz-Eikhof-Frijns membrane dynamics. The results suggest that skipping of the stimulation point …

Integrated Machine Learning And Optimization Approaches, Dogacan Yilmaz

Dissertations

This dissertation focuses on the integration of machine learning and optimization. Specifically, novel machine learning-based frameworks are proposed to help solve a broad range of well-known operations research problems to reduce the solution times. The first study presents a bidirectional Long Short-Term Memory framework to learn optimal solutions to sequential decision-making problems. Computational results show that the framework significantly reduces the solution time of benchmark capacitated lot-sizing problems without much loss in feasibility and optimality. Also, models trained using shorter planning horizons can successfully predict the optimal solution of the instances with longer planning horizons. For the hardest data set, …

Faceted Nanomaterial Synthesis, Characterizations And Applications In Reactive Electrochemical Membrane Filtration, Qingquan Ma

Dissertations

Facet engineering of nanomaterials, especially metals and metal oxides has become an important strategy for tuning catalytic properties and functions from heterogeneous catalysis to electrochemical catalysis, photocatalysis, biomedicine, fuel cells, and gas sensors. The catalytic properties are highly related to the surface electronic structures, surface electron transport characteristics, and active center structures of catalysts, which can be tailored by surface facet control. The aim of this doctoral dissertation research is to study the facet-dependent properties of metal or metal oxide nanoparticles using multiple advanced characterization techniques. Specifically, the novel atomic force microscope-scanning electrochemical microscope (AFM-SECM) and density functional theory (DFT) …

Hydrodynamic Investigation Of The Discharge Of Complex Fluids From Dispensing Bottles Using Experimental And Computational Approaches, Baran Teoman

Dissertations

The discharge of non-Newtonian, complex fluids through orifices of industrial tanks, pipes, dispensers, or packaging containers is a ubiquitous but often problematic process because of the complex rheology of such fluids and the geometry of the containers. This, in turn, reduces the discharge rate and results in residual fluid left in the container, often referred to as heel. Heel formation is undesired in general, since it causes loss of valuable material, container fouling, and cross-contamination between batches. Heel may be of significant concern not only in industrial vessels but also in consumer packaging. Despite its relevance, the research in this …

Microhydrodynamic, Kinetic And Thermal Modeling Of Wet Media Milling For Process Optimization And Intensification, Gulenay Guner

Dissertations

Nanoparticle production by wet stirred media milling (WSMM) is a common method for the formulation of poorly water-soluble drugs. While most of the studies in the WSMM literature focus on the formulation aspects to overcome the stability challenges, a thorough mechanistic understanding of the process is lacking, and the process is slow, costly, and energy-intensive. This dissertation presents experimental and modeling work with the ultimate goals of (i) gaining a deeper and more mechanistic understanding of the WSMM process and breakage kinetics of the particles using a microhydrodynamic model with various improvements and advancements, (ii) examining the heat dissipation during …

Realtime Monitoring System Of Solar Panel Performance Based On Internet Of Things Using Blynk Application, Inayatul Inayah, Nur Hayati, Aflah Nurcholis, Achmad Dimyati, Muhammad Ghofinda Prasetia

Elinvo (Electronics, Informatics, and Vocational Education)

Renewable energy is one of the options to meet the increasing energy needs. As a tropical country, Indonesia has great potential for solar energy development. At this time, solar panels have been built in places exposed to direct light. However, monitoring solar panels is still performed manually using a multimeter by operators or field officers, so it cannot be performed in real-time. Real-time tracking is carried out to prevent damage and decreased performance of solar panels. Hence, we designed a real-time solar panel monitoring system based Internet of Things (IoT) using the Blynk application on a smartphone. Based on the …

Bioremediation Of Petroleum Hydrocarbons In Coastal Sediments, Charbel Abou Khalil

Dissertations

The biodegradation of dispersed crude oil in the ocean is relatively rapid (a half-life of a few weeks). However, it is often much slower on shorelines, usually attributed to low moisture content, nutrient limitation, and higher oil concentrations in beaches than in dispersed plumes. Another factor may be the increased salinity of the upper intertidal and supratidal zones since these parts of the beach are potentially subject to prolonged evaporation and only intermittent inundation. Therefore, two laboratory experiments are conducted to investigate whether such an increase in porewater salinity results in additional inhibitory effects on oil biodegradation in seashores.

In …

Ex-Ante Cost-Benefit Analysis Of High-End And Low-Cost Wireless Sensor Network (Wsn) Technology Packages For Efficient Irrigation Water Management In The Philippines, Marielle Q. Aringo, Victor B. Ella, Camille G. Martinez, Gamiello S. Pereira

Journal of Economics, Management and Agricultural Development

Four wireless sensor network (WSN) technology packages developed for efficient irrigation water management in the Philippines were subjected to ex-ante cost-benefit analysis (CBA) to assess their financial viability. The WSN technologies include high-end and low-cost wireless sensors for upland crop production with drip irrigation system and lowland crop production with alternate wetting and drying (AWD). Results showed that the high-end WSN technology packages are only viable for high-value crops such as red onion, bell pepper, and hot pepper. The low-cost WSN technology packages are viable for all selected crops except sweet corn. Minimum areas were also generated for each crop …

Design And Development Of Aluminum Frame Unmanned Aerial Vehicle Hexacopter Configuration To Support Heavy Payload, Ulfah Mediaty Arief, Pramudyo Wicaksono, Indah Novi Yarman

Elinvo (Electronics, Informatics, and Vocational Education)

Previous research has proven that the use of Unmanned Aerial Vehicles (UAVs) can increase the efficiency of human work. However, the design of the usefulness of UAV is considered to be limited. This limitation, for example, is that the UAV's lifting capacity is only capable of lifting 3-5 kilograms of load on average. In addition, the main material of the UAV frame also uses carbon fiber produced by build-up factories abroad, this makes the UAV design less economical. Furthermore, this study discusses the development of the UAV's lifting capacity of 25 kilograms to be able to lift the pesticide liquid …

Amphiphilic Block Copolymers And The Applications In Therapeutics Delivery, Jie Dou

Dissertations

Well-defined thermo-responsive triblock copolymers containing polyethylene oxide (PEO) and poly(N-isopropyl acrylamide) PNIPAM are synthesized by a type of living controlled polymerization, named iniferter polymerization. The polymers are amphiphilic in nature and are self-assembled into a micelle. Their properties and application are characterized and investigated in this work.

Foremost, the initiator of the polymerization (iniferter) is designed and synthesized by condensation polymerization, where PEO is incorporated into the structure to improve biocompatibility, which has great potential for biological application. Moreover, this iniferter reagent could be applied to more than 70 percent of vinyl monomers.

NIPAM, a commercial vinyl monomer, is chosen …

Organic Waste Crushing Machine Automation In Eco Enzyme Production, Syamsudduha Syahrorini, Shazana Dhiya Ayuni, Fariz Zulfiryansyah, Izza Rosyidah

Elinvo (Electronics, Informatics, and Vocational Education)

In 2025, Indonesia has launched a zero-waste program. Towards a zero-waste program, of course, the community is given awareness in sorting and processing waste. Waste management is a common problem in urban or rural areas, along with the increase in population and people's lifestyles. Waste problems that are not handled properly can cause environmental problems (pollution of air, soil, and water) and public health. Based on the origin, waste is divided into organic and inorganic waste; organic waste is produced from biological materials that can be degraded by microbes or are biodegradable, or waste from fruit, vegetable, and leaf residues. …

Human Blood Grup And Rhesus Detection Tool Prototype Design Based On Iot, Trisiani Dewi Hendrawati, Inzaghi Hasanudin

Elinvo (Electronics, Informatics, and Vocational Education)

Currently, medical practitioners carry out blood type and rhesus examinations by directly observing the agglutination reaction and depending on the examiner's eye. Meanwhile, the effects of eye fatigue and saturation will cause inaccurate data. Therefore, a detection device was made which aims to display information about reading human blood type and rhesus on a digital display which can also store the data into a database. The ABO and rhesus systems were used in this study. This research was made using a real-time method based on the internet of things (IoT). sending data in real-time using WiFi Module ESP-01 and other …

Performance Analysis Of The Energy Harvesting Techniques In Cooperative Communication Systems Of Nbiot Devices With Amplify And Forward (Af) Relaying Protocol, Ines Sastre Umayya, Muhamad Milchan, Hendy Briantoro, Yoedy Moegiharto

Elinvo (Electronics, Informatics, and Vocational Education)

This study examines the system's performance with implementation of the energy harvesting (EH) techniques at source node, S and relay node, R. The RF signals which are used to energy harvesting proccess are broadcasted by destination node, D. The information signals from S are sent to D via a R in a cooperative communication framework. The R uses the amplify and forward (AF) protocol to forward the received signal from S to D. We propose a network system which contain of three femto cells, and an access point of each femto cells work as a relay (R), in a macro …

Bldc Motor Drives With A Programmable Simplified C-Block To Generate Accurate Six-Step Pwm Based On Stm32 Microcontroller, Muhammad Rizani Rusli, Mentari Putri Jati, Mochamad Ari Bagus Nugroho, Ony Asrarul Qudsi, Indhana Sudiharto, Farid Dwi Murdianto, Endro Wahjono

Elinvo (Electronics, Informatics, and Vocational Education)

This paper presents a digital implementation of a brushless direct current motor (BLDCM) drive with a six-step pulse width modulation (PWM) using a programmable simplified C-block based on the STM32 microcontroller. The implementation is conducted through the PSIM simulation platform, which is commonly used for power electronics and motor control. This approach combines the benefits of using a programmable simplified C-block for precise and flexible programming with the PWM concepts of the STM32 microcontroller. The PWM method used on the BLDCM drive is the unipolar upper PWM technique (H~PWM_L~ON). The performance of the PWM implementation is analyzed in detail, including …

Monitoring And Controlling Temperature Egg Incubator Prototype Based Lora Communication, Mas Aly Afandi, Fadhila Karin Purnomo, Raditya Artha Rochmanto, Sevia Indah Purnama

Elinvo (Electronics, Informatics, and Vocational Education)

Poultry industries encounter problem in produce day old chicken (DOC). Poultry industries usually produce DOC using egg incubator. Egg incubator must have high accuracy in reading environment temperature inside the machine. The temperature environment inside the egg incubator machine needs to keep in range 36°C - 40°C. On the other hand, hatcheries and chicken coop usually not in one place. Poultry industries require applied technology to solve this problem. This problem can be solved by using internet of things. But internet of things can be so expensive. This research is aim to implement monitoring and controlling temperature inside egg incubator …

Lead Acid Battery Recycling In The Current Tanzania Industrialization Drive: Challenges And Opportunities, Divina D. Kaombe

Tanzania Journal of Engineering and Technology (TJET)

ABSTRACT Advancements in automotive technologies, Information and Communications Technology and renewable energy technologies have increased the use of lead acid batteries as a source of portable and rechargeable energy. This has considerably increased the number of spent batteries with adverse effects on the environment and human health; which calls for recycling of spent batteries. This work was conducted to investigate challenges facing the formal business of recycling spent batteries and potential manufacturers of new lead-acid batteries in Tanzania. The work involved collection of information from key stakeholders such as collectors, dealers, Tanzania Revenue Authority and recyclers. It was found out …

2022 Scholarly Productivity Report, Missouri University Of Science And Technology

Civil, Architectural and Environmental Engineering Scholarly Productivity Reports

No abstract provided.

Modeling Of Quad-Station Module Cluster Tools Using Petri Nets, Aung Nay

Theses

The semiconductor industry is highly competitive, and with the recent chip shortage, the throughput of wafers has become more important than ever. One of the tools that the industry has deployed is to use of quad-station modules instead of the traditional single-station modules that allow for higher throughput and better wafer consistency by processing multiple wafers at the same time and distributing work. The industry trend is to use multiple transfer chamber robots to stack the quad-station modules in a series, particularly for etch products. In this work, the quad-station cluster tool wafer movement is modeled by using Petri net …

A Progress Insight Of The Formation Of Hydrogen Rich Syngas From Coal Gasification, Tawanda Matamba, Stefan Iglauer, Alireza Keshavarz

Research outputs 2022 to 2026

This review paper aims to explore the research progress in the formation of hydrogen rich gas from different innovative coal gasification parameters. Promotion effects of parameters such as pressure, temperature, catalyst, coal type, reactor setup, and gasification agents (H2O, O2, supercritical water) were extensively analysed. The formation of hydrogen gas through coal gasification was sub-divided into H2 production from fixed bed gasification system, fluidized bed system, and entrained flow system. The advantages of coal and biomass co-gasification towards clean energy formation was also reviewed. Co-gasification and elevated temperatures, pressures, and steam-carbon ratios were reported to positively influence the yields of …

Solar Irradiance Forecasting Using A Novel Hybrid Deep Ensemble Reinforcement Learning Algorithm, Seyed Mohammad Jafar Jalali, Sajad Ahmadian, Bahareh Nakisa, Mahdi Khodayar, Abbas Khosravi, Saeid Nahavandi, Syed Mohammed Shamsul Islam, Miadreza Shafie-Khah, João P. S. Catalão

Research outputs 2022 to 2026

Solar irradiance forecasting is a major priority for the power transmission systems in order to generate and incorporate the performance of massive photovoltaic plants efficiently. As such, prior forecasting techniques that use classical modelling and single deep learning models that undertake feature extraction procedures manually were unable to meet the output demands in specific situations with dynamic variability. Therefore, in this study, we propose an efficient novel hybrid solar irradiance forecasting model based on three steps. In the first step, we employ a powerful variable input selection strategy named as partial mutual information (PMI) to calculate the linear and non-linear …

Interrogating The State Of Application Of Technology Within The Malawi Maritime Force As Maritime Expression : A Task-Technology Fit Approach, Gift William Kamwendo

World Maritime University Dissertations

No abstract provided.

A Novel Biomaterial Platform For Cardiac Tissue Engineering, Andrew House

Dissertations

Heart disease is one of the leading causes of death in the world. With a growing demand for in vitro cardiac models that can recapitulate the complex physiology of the cardiac tissue, there is a desire to create novel therapies and treatments. However, due to a lack of fundamental understanding of the heart's inflammatory response to myocardial infarction, the development of new therapies is both time consuming and costly. In this work, a novel approach to fabricating a dynamic hydrogel cardiac platform is reported. This platform better mimics the dynamic changes occurring in the native cardiac tissue microenvironment during cardiac …

Characteristics Of Extreme Precipitation And Their Effect On Bean Yield In Rwanda, Paul Ts Limbu Sr

Tanzania Journal of Engineering and Technology (TJET)

This study examines the characteristics of extreme precipitation and its effect on bean yield in Rwanda from 1981 to 2017. Over the study area, two rainy seasons, March to May (MAM) and September to December (SOND), account for approximately 80% of total rainfall. The spatial distribution of rainfall over Rwanda revealed that the first three EOF modes of MAM rainfall vary by 72.72 percent over the study period, while the first three EOF modes of SOND rainfall vary by 57.48 percent. The spatial analysis of extreme precipitation reveals that during wet years, the majority of the country's western regions receive …

A Chemical Study Of Archaeometallurgical Ceramics From Southwestern Tanzania, Edwinus Lyaya

Tanzania Journal of Engineering and Technology (TJET)

Archaeometallurgical ceramics, including furnaces, tuyères, and potteries, were required for successful pre-industrial iron smelting and refining. However, there are limited chemical studies on archaeometallurgical ceramics in Tanzania. This paper examined the nature of clay source in terms of refractoriness, determined whether there were multiple clay sources, and verified the refractoriness of the archaeometallurgical ceramics. An x-ray fluorescence (XRF) analytical technique and experimental re-firing of the archaeometallurgical ceramics were employed. The chemical data clustered in the mullite region on the Al2O3-SiO2-FeO ternary system indicate that iron smelters and refiners chose refractory clay sources for making archaeometallurgical ceramics. Small range and standard …

Properties Of (Cd, Zn)S Films Deposited By Dc Co-Sputtering, Lwitiko P. Mwakyusa

Tanzania Journal of Engineering and Technology (TJET)

CdS thin film is commonly used as a buffer layer in most thin film solar cells. However, the buffer layer with less absorption in the visible region of the solar spectrum as well as that which provides perfect lattice matching with the absorbers is required. The incorporation of Zn in the CdS films can affect the structural and optical properties of the buffer layer. In this work, films of CdS and (Cd,Zn)S films were deposited by DC sputtering utilizing CdS and Zn targets. The concentration of Zn in the CdS was varied by changing the sputtering power of the Zn …

Filtering Effect On Rssi-Based Indoor Localization Methods, Kwame S. Ibwe

Tanzania Journal of Engineering and Technology (TJET)

Indoor positioning systems are used to locate and track objects in an indoor environment. Distance estimation is done using received signal strength indicator (RSSI) of radio frequency signals. However, RSSI is prone to noise and interference which can greatly affect the accuracy performance of the system. In this paper Internet of Things (IoT) technologies like low energy Bluetooth (BLE), WiFi, LoRaWAN and ZigBee are used to obtain indoor positioning. Adopting the existing trilateration and positioning algorithms, the Kalman, Fast Fourier Transform (FFT) and Particle filtering methods are employed to denoise the received RSSI signals to improve positioning accuracy. Experimental results …

A Genetic Algorithm Approach To Optimal Sizing And Placement Of Distributed Generation On Nigerian Radial Feeders, Adelowo Balogun

Tanzania Journal of Engineering and Technology (TJET)

Mitigating power loss and voltage profile problems on radial distribution networks has been a major challenge to distribution system operators. While deployment of distributed generation, as compensators, has made a suitable solution option, optimum placement and sizing of the compensators has been a concern and it has thus been receiving great attention. Meta-heuristic algorithms have been found efficacious in this respect, yet the use of the algorithms in addressing problems of radial feeders is still comparatively low in Nigeria where analytical and numerical programming methods are common. Hence; the use of genetic algorithm to site and size distributed generator for …

Review Of The Imaging Performance And The Current Status Of The Cascade Gamma-Rays Coincidence Imagers, Leonid L. Nkuba Dr.

Tanzania Journal of Engineering and Technology (TJET)

Various studies that have investigated the detection of gamma coincidence events have revealed that design factors and image reconstruction approaches dictate the spatial resolution, coincidence efficiency, and levels of statistical noise of the detection system. In the case of imaging, cascade gamma-ray coincidence (CGC) imagers coupled with collimated detectors offer promising values for both spatial resolution and coincidence efficiency. However, to date, no CGC imager with single or multiple collimated detectors has reported a performance level beyond 6.7 mm spatial resolution (FWHM) and 6.0 × 10-6 coincidence efficiency. Given the recent developments and the current interests in high resolution and …

Assessing Morphological Changes Of The Msimbazi River Using Satellite Images, Fides J. Izdori

Tanzania Journal of Engineering and Technology (TJET)

This study assessed historical morphology changes of the Msimbazi River in Dar es Salaam City, Tanzania, following heavy rainfall events using historical Google earth images. The erosion and sedimentation processes that cause morphological changes of a river are also associated with flooding within the river catchments. In this study, the bank-line movement, erosion and sedimentation areas and changes in river section width were analyzed under three-time periods: 2005- 2012, 2012- 2018, and 2018- 2020. Data shows that, the timing for floods coincides with the historical records for heavy rains. It was found that, area in the upper reaches of the …