Engineering Commons^™

Study Of Radiation Effects In Gan-Based Devices, Han Gao

Electrical Engineering Theses and Dissertations

Radiation tolerance of wide-bandgap Gallium Nitride (GaN) high-electron-mobility transistors (HEMT) has been studied, including X-ray-induced TID effects, heavy-ion-induced single event effects, and neutron-induced single event effects. Threshold voltage shift is observed in X-ray irradiation experiments, which recovers over time, indicating no permanent damage formed inside the device. Heavy-ion radiation effects in GaN HEMTs have been studied as a function of bias voltage, ion LET, radiation flux, and total fluence. A statistically significant amount of heavy-ion-induced gate dielectric degradation was observed, which consisted of hard breakdown and soft breakdown. Specific critical injection level experiments were designed and carried out to explore …

A Special Issue: Electric Machinery And Transformers, Huseyin R. Hiziroglu

Electrical & Computer Engineering Publications

As the demand for electrical energy increases worldwide, engineers and scientists have been investigating new electrical systems and materials to meet this demand economically, having large-scale planning and employing environmentally friendly energy production and energy-efficient systems for consumption to minimize adverse environmental effects. New applications such as renewable energy production, e-mobility, and aerospace technology can be considered within the scope of this perspective. Thus, it is a necessity to establish new paradigms in the design, construction, and selection of new materials and drive systems for electric machines and transformers, where such stringent requirements, as high power density, low weight, compact …

Empowering 5g Mmwave: Leveraging Kml Placemarks For Enhanced Rf Design And Deployment Efficiency, Gustavo A. Fernandez

School of Mathematical & Statistical Sciences Faculty Publications

This publication explores the significance of Keyhole Markup Language (KML) in telecommunications, particularly in the context of 5G mmWave RF design and planning. With the advent of 5G mmWave technology, the demand for seamless and efficient network deployments has never been greater. The deployment of small cells and repeaters for 5G mmWave necessitates utmost precision in location accuracy and rapid information exchange during site surveys and evaluations. The challenges of mmWave frequencies, including their limited range and susceptibility to attenuation, intensify the complexity and criticality of this process. Network operators must ensure that the chosen location is devoid of obstacles …

Water Hammer Analysis For Ash Slurry Disposal Pipelines Of A Thermal Power System, Biprodip Mukherjee, Subhasish Das, Satyapriya Mandal

Journal of Environmental Science and Sustainable Development

Coal-ash slurry transportation via pipelines has been accepted as a potential, economical, and dependable mode of two-phase flow of solid-liquid transportation. It is solid-liquid transportation where the ash slurry generally flows through mild steel, and a good amount of pump energy and pressure is required to convey the slurry with a density above 1220 kg/m3. The study is basically on the water hammer analysis of ash slurry conveying pipes. Nevertheless, since the hammer analysis is typically carried out in normal water, the study of ash slurry is compared to the know criteria of potable water. The study aims to understand …

River Meanders On Alluvial Plains And Hilly Topography, Puguh Dwi Raharjo, Eko Haryono, Muhammad Anggri Setiawan, Haryadi Permana

Journal of Environmental Science and Sustainable Development

Previous research on meandering rivers in Indonesia, precisely in Java, has predominantly focused on alluvial plains, while their presence is also observed in hilly regions with rocky substrates. The study aims to investigate different meandering types in Java and establish regional connections between these types and geological and geomorphological processes. The methodology involves identifying high-resolution remote sensing images and topographic data, followed by analysis based on geological and geomorphological developments. To categorize the rivers, sinuosity ratios are meticulously calculated. The tectonic setting, which influences physiography and geomorphology, is an analytical unit for determining the meandering process. The result reveals that …

Nickel Recovery From Low-Grade Laterites: Study Of Thermal Pre-Treatments To Improve The Efficiency Of The Hydrometallurgical Process, Johana Borda, Robinson Torres

Journal of Sustainable Mining

The processing of lower-grade laterites to obtain nickel has increased due to the gradual depletion of higher-grade sulphide ore reserves. However, the extraction from laterites has been limited because conventional technologies imply a considerable expense of energy or reagents. In this document, the effect of thermal pre-treatments on a laterite sample is demonstrated to improve nickel leaching under moderate conditions. The influence of agents such as coke, coal and NaCl in the heat treatment was also studied. With the results it is presumed that part of the nickel occluded in the goethite migrates to the iron oxides surface during the …

European Feedback On Post-Mining Seismicity, Isabelle Contrucci, Dalija Namjesnik, Peter Niemz, Paloma Primo, Andrzej Kotyrba, Grzegorz Mutke, Petr Konicek, Pascal Dominique, Tobias Rudolph, Stefan Möllerherm, Jannes Kinscher, Emmanuelle Klein, Simone Cesca

Journal of Sustainable Mining

Following the Paris Agreement adopted in 2015, Europe has committed to reducing its greenhouse gas emissions. In this context, the abandonment of coal as an energy source, both in terms of consumption and production, will lead to the closure of many mines in the years to come.

Mine closure guidelines to manage residual mining risks already exist in European countries. However, they do not include post-mining seismic risk management due to a lack of sufficient studies and knowledge on this subject. After mining closure, the flooding of the mining works leads to hydromechanical loading of the underground and, in the …

Removing Ilmenite-Based Filter Cakes Using Hydrochloric Acid And Chelating Agent – Experimental Study, Jianping Su, Omar Mahmoud, Hisham A. Nasr-El-Din

Future Engineering Journal

Ilmenite is often used as a weighting agent in drilling fluids to increase the fluid density, but the formation of a filter cake on the borehole wall can impact cementing operations and reduce well productivity. To remove the filter cake, various techniques can be employed such as chemical treatments, mechanical methods, or a combination of both. The goal of this study is to evaluate the effectiveness of chemical removal of ilmenite-based filter cake using 7.5 wt.% hydrochloric acid (HCl) and hydroxyethyl ethylenediamine triacetic acid (HEDTA) – chelating agent. The filter cakes were generated using API filter press under harsh conditions …

Evaluation Of Static Horizontal Louvers On Annual Daylighting Performance In Classrooms, Kamal A. Saleem, Samir S. Hosny, Ashraf Nessim

Future Engineering Journal

Daylighting has a great impact on students’ health, learning performance, and productivity. The goal of this paper is to enhance daylighting performance by examining year-round daylighting performance of Southern facades in the case of one central window in a classroom located in Cairo, Egypt by using static external horizontal shading devices during the Fall, Spring and Summer semesters The scope of the study is to evaluate and assess the effect of the window-to-wall ratio (WWR) in addition to the louvers’ configurations of depth and count parameters of the classroom on annual daylighting performance metrics for classrooms’ southern facades by using …

Missing Value Imputation For Single Omics And Multi-Omics Data, Meng Song

Dissertations

The integration analyses of multi-omics data have the advantages of extending our understanding of biological system across multiple omics layers, unraveling the functional mechanism of complex disease development, and refining the discovery of novel drug targets. However, multi-omics studies often face challenges such as data heterogeneity, missing values problem, interpretability, and imbalance classes. Among these challenges, the missing values problem is a critical issue for large cohort studies as not all samples will get a complete measurement for all the omics layers. To address the problem of missing values in multi-omics data, I focused on the imputation of completely missing …

Neutrosophic Gsα* - Open And Closed Maps In Neutrosophic Topological Spaces, P. Anbarasi Rodrigo, S. Maheswari

Neutrosophic Systems with Applications

The main aim of this paper is to introduce a new concept of Neu-mapping namely Neugsa*-open maps and Neugsa* -closed maps in Neu-topological spaces. Additionally, we relate the properties and characterizations of these mappings with the other mappings in Neu-topological spaces.

Deep Learning For Multi-Structured Javanese Gamelan Note Generator, Arik Kurniawati, Eko Mulyanto Yuniarno, Yoyon Kusnendar Suprapto

Knowledge Engineering and Data Science

Javanese gamelan, a traditional Indonesian musical style, has several song structures called gendhing. Gendhing (songs) are written in conventional notation and require gamelan musicians to recognize patterns in the structure of each song. Usually, previous research on gendhing focuses on artistic and ethnomusicological perspectives, but this study is to explore the correlation between gendhing as traditional music in Indonesia and deep learning technology that replaces the task of gamelan composers. This research proposes CNN-LSTM to generate notation of ricikan struktural instruments as an accompaniment to Javanese gamelan music compositions based on balungan notation, rhythm, song structure, and gatra …

Neutrosophic Gsα* - Open And Closed Maps In Neutrosophic Topological Spaces, P. Anbarasi Rodrigo, S. Maheswari

Neutrosophic Systems with Applications

The main aim of this paper is to introduce a new concept of Neu-mapping namely Neugsa*-open maps and Neugsa* -closed maps in Neu-topological spaces. Additionally, we relate the properties and characterizations of these mappings with the other mappings in Neu-topological spaces.

Mechanical Properties Of Biocomposite With Various Composition Of Caco3 And Starch, Agris Setiawan, Fransisca Diana Wahyuningsih, Riria Zendy Mirahati

Journal of Mechanical Engineering Science and Technology (JMEST)

Calcium carbonate has the potential to be used in the development of medical materials, including biomaterials. Biocomposite is composed of CaCO3 as matrix material and bioplastic from the combination of corn starch and cassava starch as reinforcement. This study aims to determine mechanical properties such as tensile strength and bending/flexural strength with varying compositions of CaCO3 and bioplastic. Characterization of the biocomposite uses Scanning Electron Microscope to observe the microstructure and composition elements of their structure. This study used 4 variations in the ratio of CaCO3 suspension: (Corn Starch + Cassava Starch). Each sample was characterized using specimen code A …

Synthesis And Characterization Of Nitrogen-Doped Activated Carbon For Lithium Battery Anode Applications, Prihanto Trihutomo, Poppy Puspitasari, Muhammad Bustomi Radja, Milzam Rahmat Busono

Journal of Mechanical Engineering Science and Technology (JMEST)

Nitrogen-dopped activated carbon was synthesized to see its effect on the characterization of the nitrogen surface functional groups, crystal size, and morphology of the resulting sample. Synthesis of nitrogen-doped activated carbon was carried out by varying the addition of Urea as a nitrogen doping source. Activated carbon compared its characteristics with variations in the concentration of added Urea to activated carbon, at 1:3 and 1:5. The FTIR results obtained were the presence of functional groups indicating the presence of nitrogen bonds in each sample. The crystallinity results showed that the samples were classified as crystalline and nitrogen doping influenced the …

Designing A Naabsa Class Tanker Ship With Bottom Protection From Ground, Victor A. Kulesh, Mathias B. Prasetio, Fam Chung Hiep

Journal of Mechanical Engineering Science and Technology (JMEST)

Indonesia is the world's largest archipelago country with a high potential for economic development and top producer and exporter of palm oil. As an archipelago country, the most efficient cargo transportation routes are through rivers and seas. Designing and building tankers, taking into account the specifics of the operation, are relevant. The paper considers the issues of designing a tanker for the transportation of crude palm oil with a defined operation area and route. The general concept of the vessel is proposed, taking into account the restrictions on the navigation area and draft for operation in the river. Particular attention …

Effect Of Grafting Nano-Tio2 On Sansevieria Cylindrica Fiber Properties, Chrisrulita Sekaradi Wiguna, Heru Suryanto, Aminuddin Aminuddin, Jibril Maulana, Joseph Selvi Binoj, Alamry Ali

Journal of Mechanical Engineering Science and Technology (JMEST)

Natural fibers, which are abundant, environmentally friendly, and biodegradable, are used as a replacement for synthetic fibers. The composite strength can be increased by treating the surfaces of natural fibers with suitable chemicals, which can also improve the interface interaction between fiber and matrix. Application of a coupling agent in chemical treatment is utilized to reinforce the bonding between fiber and matrix. The objective of the study is to determine the influence of silane concentration on the Sansevieria cylindrica fiber properties. The methods included fibers treatment using ethanol and coupling agent as dissolving and TiO2 with concentrations of 0%, 0.25%, …

The Combustion Characteristics Of Calophyllum Inophyllum Fuel In The Presence Of Magnetic Field, Imam Rudi Sugara, Nasrul Ilminnafik, Salahuddin Junus, Muh Nurkoyim Kustanto, Yuni Hermawan

Journal of Mechanical Engineering Science and Technology (JMEST)

The study objective is to investigate the combustion characteristics of Callophyllum inophyllum fuel in presence of a magnetic fields. To conduct the experiment, a bunsen burner was utilized, with fuel and air being dispensed via a syringe pump and compressor, both regulated by a flowmeter. The fuel and air pipes were heated to 532.15 (K) to facilitate fuel evaporation. The equivalent ratio of 0.5, 1, and 1.5 was adjusted to control air discharge and fuel. An 11,000 gausses artificial magnet was used, with N-S, N-S, N-N, and SS being the various magnetic pole configurations. The study found that the magnetic …

Effect Of Current And Pulse-On Time On Material Removal Rate And Surface Roughness Of Tungsten Carbide In Electric Discharge Machine Die-Sinking, Mochamad Deny Riyanto, Andoko Andoko, Heru Suryanto

Journal of Mechanical Engineering Science and Technology (JMEST)

The focus of manufacturing for tungsten carbide applications often demands a smooth surface quality as the result of the Electric Discharge Machine (EDM) die-sinking process, especially in the manufacture of die and mold with tungsten carbide material processed using a die-sinking EDM machine. The purpose of this study is to analyze the effect of electric current and pulse-on time on the Material Removal Rate (MRR) and surface roughness of tungsten carbide. Through the experimental method, the parameters varied, namely electric current 17 A, 20 A, 23 A, and pulse-on time 30 µs, 55 µs, and 80 µs. MRR was calculated …

Lap Joint On St.37 Steel Plate With Friction Welding Clamping Method, Widia Setiawan, Nugroho Santoso, Wiyadi Wiyadi, Muhammad Sulistiyo Aji, Rachmat Alamin, Achsan Tarmudi

Journal of Mechanical Engineering Science and Technology (JMEST)

Friction stir (FW) welding is a relatively fresh method that was created and has been continually refined and adapted to industrial applications due to its benefits. This approach for solid-state joining entails connecting the components at a temperature below their melting point and then heating them up. Clamp joint applications are widely used using external heating and hitting with high strength, but the clamped joints with the FW method are rarely done. The research studied the characteristic of clamped joints at various plate thicknesses using the FW method. In this study, 30 specimens were used in the form of a …

The Effect Of Cutting Speed Of Nitrogen Laser Cutting On The Surface Texture Of Sus 304 Plate, Yanuar Rohmat Aji Pradana, Raka Afrianto, Chandra Hairat Abdul Rahman, Andoko Andoko

Journal of Mechanical Engineering Science and Technology (JMEST)

The focus of today’s machining industry is on how to maintain high productivity and low cost achieved by high tool life during the operation. Laser cutting is considered the right solution because it offers cutting speeds of up to 170000 mm/min through a non-contact process regardless of the workpiece material hardness. The aim of this study is to analyze the effect of cutting speed on the surface texture aspects namely surface roughness, kerf shape, and dross height on the stainless steel 304 plate after laser cutting. The nitrogen laser was utilized with the cutting speed of 400, 1700, and 2000 …

Analysis Of Fire And Smoke Spread In Ki Hajar Dewantara Auditorium, State University Of Jakarta, Using Fire Dynamics Simulator, Pratomo Setyadi, Ariq Harits Arrizq

Journal of Mechanical Engineering Science and Technology (JMEST)

Fire behavior and smoke spread are influenced by various factors, including the amount and condition of combustible material, ventilation openings, and ceiling height. A high amount of combustible material in the auditorium poses a significant fire hazard, hence, efforts need to be made to minimize the risk. One approach is to use Computational Fluid Dynamic software, such as Fire Dynamics Simulator (FDS), to model fire combustion. In this research, it provides an overview of the heat release rate (HRR) of fires that occur as well as the effect of differences in ceiling height and the effect of ventilation on fire …

Effect Of Temperature Variations Of Corn (Maize) Oil Biodiesel On Torque Values And Thermal Efficiency Of Diesel Engines, Suardi Suardi, Rodlian Jamal Ikhwani, Ade Putri Rezki Aulia

Journal of Mechanical Engineering Science and Technology (JMEST)

The trend of consumption of hydrocarbon fuels in Indonesia, which is increasing every year, is not accompanied by the amount of production, which is decreasing. Alternative fuels to reduce dependence on hydrocarbon fuels. One form of alternative fuel is biodiesel, which is made from corn (maize) oil. Corn oil itself, if processed, can be an option for clean and environmentally friendly energy option and that is the main objective of this research is to determine the performance of biodiesel corn oil on diesel engines. The method used in this study is an experimental method where corn oil biodiesel is tested …

Impacts And Applications Of Vegetable Glycerin On Nanocellulose, Elise Hong-Miller, Dylan Seiffert, T. E. Kidd

Summer Undergraduate Research Program (SURP) Symposium

Nanocellulose is created by breaking down cellulose, the most common organic molecule found in nature. Nanocellulose has attractive properties, such as a very high strength-to-weight ratio, for many different applications. A major challenge is that nanocellulose has a very high shrinkage % (~90%) when it is dried, as well as a strong probability to crack. Different additives can be added in varying amounts to either mitigate or intensify these aspects, as well as affect its drying conditions. This investigation is helping the National Aeronautics and Space Administration (NASA) and the U.S. Army to find a use for this highly renewable …

Flow Through Processing Of Nanocellulose For Space Exploration Applications, Dylan Seiffert, T. E. Kidd

Summer Undergraduate Research Program (SURP) Symposium

Nanocellulose is synthesized from cellulose, which is the most abundant organic molecule found in nature. Nanocellulose solids are biodegradable and have a strength-to-weight ratio eight times that of steel¹. The production of nanocellulose solids is challenging due to the large volume loss that occurs during the curing process as well as the time and cost associated with ultrasonic processing. The loss of volume during curing often results in cracking and deformation of the cured solid. The issues caused by the large volume loss can be mitigated using additives that do not compromise the strength, shape, or machineability of …

Integrating External Sensors With Crazyflie Drones, Xiaowen Wang, Dheryta Jaisinghani, Andrew Berns

Summer Undergraduate Research Program (SURP) Symposium

• Drones are widely used: Mini drones such as Crazyflie 2.1 are used in a variety of fields.
• Grove Sound Sensor function: Grove Sound Sensor can capture sound, providing more application possibilities for drones.
• The potential of Crazyflie 2.1: Although Crazyflie 2.1 has the potential to be an integrated sensor platform, prior to this project, it was uncertain whether sensors could be connected on it.
• Project motivation: Our project aims to explore whether Crazyflie 2.1 can be connected to the Grove Sound Sensor and collect and process data from the sensor.
• Impact of the project: If successful, this project will open …

Molybdenum Disulfide (Mos₂) As A Nanocellulose Substrate, Mariana Torres, Dylan Seiffert, Elise Hong-Miller, T. E. Kidd

Summer Undergraduate Research Program (SURP) Symposium

Cellulose is a substance abundant in nature, found in fruits and vegetables, plant cell walls (National Center for Biotechnology Information, 2023), and wood (Sjostrom, 1993). The abundance of cellulose is attributable to its linear chemical structure, as it is composed of long strands of glucose molecules linked together by hydrogen atoms, which enable the substance to withstand significant pressure without breaking (Rongpipi et al., 2019). This property—known as high tensile strength—is joined by its non-toxicity and sustainability, given cellulose may be degraded and renewed naturally (Kaur, 2021). These various properties indicate versatility, and its resultant current and desired uses—such as …

Recent Progress Of Bifunctional Electrocatalysts For Oxygen Electrodes In Unitized Regenerative Fuel Cells, Tian-Long Zheng, Ming-Yu Ou, Song Xu, Xin-Biao Mao, Shi-Yi Wang, Qing-Gang He

Journal of Electrochemistry

Unitized regenerative fuel cells (URFCs), which oxidize hydrogen to water to generate electrical power under thefuel cells (FCs) mode and electrolyze water to hydrogen under the water electrolysis (WE) mode for recycling, areknown as clean and sustainable energy conversion devices. In contrast to the hydrogen oxidation reaction (HOR) andhydrogen evolution reaction (HER) on the hydrogen electrode side, the sluggish kinetics of oxygen reduction reaction(ORR) and oxygen evolution reaction (OER) on the oxygen electrode side requires highly efficient bifunctional oxygencatalysts. Conventional precious metal oxygen catalysts combine Pt and IrO₂ with excellent ORR and OER activities toachieve bifunctional electrocatalysis performance, but …

Ultramicroelectrode Experiments: Principles, Fabrications And Voltmmetric Behaviors, Zhen Ma, Jia-Yang Lin, Wen-Jing Nan, Lian-Huan Han, Dong-Ping Zhan

Journal of Electrochemistry

Due to the small size at least in one dimension (< 25 μm), ultramicroelectrode (UME) has small electric-double-layer capacitance, low IR drop, rapid mass transfer rate, fast response, high signal/noise ratio and high spatiotenporal resolution. UME is qualified not only to study the kinetics of fast electrode processes, but also to act as the probe of scanning electrochemical microscopies to obtain the localized chemical or electrochemical reactivity of the substrates. Thus, UMEs play a significant role in various research domains of electrochemistry, and have become an important electrochemical experimental method. Herein, we will introduce the basic principles, a simple fabrication method and voltammetric experimental protocols of UME, providing a guide to carry out the UME experiments.

Band Alignments Of Metal/Oxides-Water Interfaces Using Ab Initio Molecular Dynamics, Yong-Bin Zhuang, Jun Cheng

Journal of Electrochemistry

Band alignments of electrode-water interfaces are of crucial importance for understanding electrochemical interfaces. In the scenario of electrocatalysis, applied potentials are equivalent to the Fermi levels of metals in the electrochemical cells; in the scenario of photo(electro)catalysis, semiconducting oxides under illumination have chemical reactivities toward redox reactions if the redox potentials of the reactions straddle the conduction band minimums (CBMs) or valence band maximums (VBMs) of the oxides. Computational band alignments allow us to obtain the Fermi level of metals, as well as the CBM and VBM of semiconducting oxides with respect to reference electrodes. In this tutorial, we describe …