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 …

2022 Scholarly Productivity Report, Missouri University Of Science And Technology

Civil, Architectural and Environmental Engineering Scholarly Productivity Reports

No abstract provided.

Nozzle Reactive Hydroturbine With Guide Device, O O. Bozarov, Kh S. Usarov, R Aliyev, S F. Ergashev

Technical science and innovation

The article presents the principle of operation of a jet turbine with a nozzle based on the "Segner" wheel and studies its shortcomings. In order to eliminate the identified shortcomings, a guide device was developed, which is installed inside the hydraulic turbine impeller. Using the Bernoulli equations and the Zhukovsky theory, the energy parameters of a microhydroelectric power station with a developed divertor device and the water flow rate in a hydroturbine are determined. The energy parameters calculated on the basis of theoretical results are analyzed, and it is found that the efficiency of a hydroturbine increases by 10-20% depending …

Recent Trends In Mineral Processing Based On Density And Particle Size–A Review, Ahmed Sobhy

Mining Engineering Faculty Research & Creative Works

Most mineral beneficiation development in the world focus on size and density-based separation technologies. In recent years, ore size-based and density-based separation technologies have attracted more consideration to obtaining rough or final high-quality products. Due to the dissimilarity of physical properties like particle size and density, valuable and gangue minerals can be segregated via size-based and density-based separation technologies. Removing the impurities and recovering the target minerals are accomplished by size-based separation technologies alone or are usually followed by cleaning processes utilizing density-based separation abilities. The density variation among valuable and gangue minerals leads to dissimilarities in settling velocity in …

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 …

Manufacturing Of Instrument Structures From Formed Silicide Films, I R. Bekpulatov

Technical science and innovation

This work provides information on the formation of the main part of thermal radiation receivers. In addition, the article defines and creates optimal modes for creating targets for magnetron sputtering from higher manganese silicide (Mn4Si7) and cobalt monosilicide (CoSi). As is known, the device is formed from a two - type film, where the Mn4Si7 film gives the p - type, and the CoSi film gives the n - type. Films were formed using these targets by magnetron sputtering and their electrophysical properties were studied. The results obtained showed that the resulting films …

Preparation Of Azomethine Derivatives (Schif Bases) Chitosan Apis Mellifera, A S. Mengliev, G A. Ikhtiyarova

Technical science and innovation

Chitin and chitosan should be considered as derivatives of cellulose. The basis for such an approach to these polysaccharides is their chemical structure. The macromolecular chains of these polymers are formed by glucopyranose cycles, which, being connected by β- (1→4) glucosidic bonds, form linear polymer chains. The biological functions and mechanical properties of these polysaccharides are largely determined by the conformation of macromolecules and the distribution of reactive groups in them. Due to the unique properties of chitin and chitosan, they are becoming increasingly important in the practical and especially in the medical and biological activities of mankind. The aim …

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 …

Concrete Technology In A Rapidly Growing Urban Environment – The Case Of Dar Es Salaam City, John K. Makunza Jkm

Tanzania Journal of Engineering and Technology (TJET)

Concrete is a building material that is used in great quantities second only to our use of water. The ingredient materials of concrete include cement, fine and coarse aggregates plus a reasonable amount of water, and sometimes additives. The construction of various structures like, residential buildings, commercial buildings, hospitals, schools, bridges, etc., needs good quality concrete. Good modern technologies are needed by the construction industry in order to effectively construct buildings which are durable. A study has been done with the main objective of assessing the concrete technologies existing in rapid growing cities in Sub-Sahara Africa like Dar es Salaam, …

Development Of An Operational Satellite-Based Flood Monitoring Model For Tanzania, Andrew Kimati

Tanzania Journal of Engineering and Technology (TJET)

Timely information during water related disasters is of utmost importance for flood preparedness and risk reduction. However, the conventional ground-based photographic monitoring of flooded areas is an expensive and time-consuming exercise. Satellite remote sensing is a quick and affordable approach that can be used for concurrent floods detection at different scales. This is important as it facilitates timely information for emergency response to disaster management departments, even in scarcely instrumented catchments. This study presents a novel approach for flood tracking using satellite image remote sensing science to map flood affected areas immediately after occurrence of rainfall events. An open-source water …

Analysis Of Ore Hand-Crushed Size Distribution For Grinding Process In The Artisanal And Small-Scale Gold Mines Production: A Case Study Of Nholi Mine, Bahi District, Malugu Tembo

Tanzania Journal of Engineering and Technology (TJET)

(ASGM) employed numbers of people compared to large-scale mines. The ASGM has been played a crucial role in poverty alleviation and rural development, particularly in developing countries. The mined ore is crushed and ground for beneficiation of gold. The grinding process involved the size reduction of blasted materials to acquire minerals of interest. This paper presents the size distribution of hand-crushed for blasted materials using sieve analysis and digital image processing. The sieve test results for hand-crushed blasted material of three muck-piles were ranged between 17 mm and 36 mm that is equivalent to 20% and 80% passings respectively, with …

Deployment Of Inductive Loop Vehicle Traffic Counters Along Trunk Roads In Tanzania, Daudi Simbeye

Tanzania Journal of Engineering and Technology (TJET)

As Tanzania's population grows, there is a greater demand for efficient, effective, and strong road design, as well as a smooth transportation system with a balanced traffic management network architecture. To plan for maintenance and expansion of such a vast network, a credible data inventory and network condition must be established. The deployment of vehicle inductor loop counters along Tanzanian trunk roads is presented in this paper. At test sites, inductor loop sensors and control cards were used to capture vehicle traffic data, which was then wirelessly sent using GSM technology for vehicle classification verification and storage for future road …

Design And Implementation Of Cardiopulmonary Resuscitation Simulation Model, Mbazingwa Mkiramweni

Tanzania Journal of Engineering and Technology (TJET)

Cardiopulmonary resuscitation (CPR) is a life-saving procedure that can multiply a person's chances of survival after a cardiac arrest. The effectiveness of CPR procedures is heavily influenced by the individual skills of the rescuer providing assistance. Chest compressions delivered at an appropriate depth and rate, allowing full chest recoil and with minimal interruptions, are critical for improving cardiac arrest survival. The lack of quality CPR training models in developing countries has a significant impact on the quality of CPR training and skills acquired. Therefore, in this paper, we aim at improving CPR training by designing a high-fidelity CPR training manikin. …

Synthesis, Characterisation And Catalytic Evaluation Of Castor Oil-Templated Mesoporous Sulfated Solid Acid Catalysts For Esterification Reaction, Steven Nyandoro Pr

Tanzania Journal of Engineering and Technology (TJET)

In bio-refinery and other catalytic reactions, heterogeneous catalysts confer advantage over homogenous catalysts due to minimized recovery and separation costs. However, templating surfactant and solid support for the synthesis of heterogeneous catalysts ought to consider their cheap sources and environmentally friendliness for their sustainable use. Thus, with the vision to make the process significantly benign, in the present work, solid acids were synthesised from renewable sources (castor oil as surfactant and rice husk as the source of silica). The synthesised castor oil-templated mesoporous sulfonic acid modified catalysts (SO3H-MTS and SO3H-MT-RHS) were characterised and evaluated for catalytic esterification of acetic acid …

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 …