Engineering Commons^™

Thermal Behavior Of Solid Acids In The Rb3h(So4)2-Rbhso4 System Under Ambient Atmosphere, Chatr Panithipongwut Kowalski, Permpoon Chaijaroen, Farook Kaewniyom

Journal of Metals, Materials and Minerals

The thermal behavior of solid acids in the Rb3H(SO4)2-RbHSO4 system under ambient atmosphere has been studied in comparison to the previously reported high-temperature behavior of the same system under humidified atmosphere. The findings showed that, under this level of humidity, the transition of RbHSO4, the transition of Rb5H3(SO4)4, and the disproportionation of Rb3H(SO4)2, occurred at the same temperatures as those under humidified atmosphere. However, the results from differential scanning calorimetry did not reveal the reaction temperature between Rb3H(SO4)2 and RbHSO4 due to the slow process. The dehydration temperatures of Rb5H3(SO4)4 were surprisingly similar between the systems under low and high …

Graphene Enhanced Linear Low-Density Polyethylene Nanocomposites By Premixing And Melt Compounding, Wan Nazri Wan Busu, Ruey Shan Chen, Muhammad Jefri Mohd Yusof, Sahrim Ahmad

Journal of Metals, Materials and Minerals

In this study, linear low-density polyethylene/graphene nanoplatelets (LLDPE/GNPs) nanocomposites were prepared from conventional melt-mixing method and our new approach; two-step premix mixing technique. Indirect mixing technique (IDT) was employed to fabricate a premix of LLDPE/ GNPs in the ratio of 80:20 wt%. The effects of GNPs loadings and the processing method of nanocomposites on the mechanical strength, decomposition temperature, crystallinity, electrical impedance and morphology were investigated. Irrespective of processing methods, the prepared nanocomposites exhibited crystalline structure due to the presence of GNPs whilst the degradation temperature was recorded to be increased with GNPs loadings that signified improved thermal stability. The …

Preparation Of Transparent Alumina Thin Films Deposited By Rf Magnetron Sputtering, Busarin Noikaew Noikaew, Laksana Wangmooklang, Saisamorn Niyomsoan, Siriporn Larpkiattaworn

Journal of Metals, Materials and Minerals

Alumina (Al2O3) thin films were prepared by RF magnetron sputtering technique using Al2O3 ceramic target. Effects of sputtering powers and oxygen gas mixtures were investigated and the optimized coating condition was applied on semi-precious gemstones. RF sputtering powers were varied to optimize the transparency of the films. Besides, the oxygen gas mixtures were also studied at the optimized sputtering power with a constant sputtering pressure. Optical and physical properties of the thin films were investigated using UV-Vis Spectrophotometer, FESEM, XRF, GIXRD, XRR including a microscratch tester. The Al2O3 films were highly transparent in the visible region in form of an …

Extraction Of Cellulose Nanofibers From Empty Palm Fruit Bunches Via Mechanical Defibrillation, Zi-Qian Tan, Takaomi Kobayashi, Duangdao Aht-Ong

Journal of Metals, Materials and Minerals

In recent years, there has been an increasing interest in finding alternative material to replace fossil-oil based product due to the environmental concern. Lignocellulosic biomass has emerged as the promising candidate due to its low-cost and sustainability. The objective of this work was to prepare cellulose nanofibers (CNFs) from empty palm fruit bunches (EPFB), which are the waste originating from palm oil industry. Cellulose fibers were first extracted from EPFB by chemical treatment, followed by mechanical disintegration using high-pressure homogenization. Fiber concentration and defibrillation time during mechanical treatment were studied to investigate their effects on the properties of produced nanofibers. …

The Effect Of Phosphogypsum On Stabilizing Clay Soil And Improving Its Properties For Use As Foundation Soil, Mai Yahya Maaitah, Mus'ab Ziad Banat

Journal of Metals, Materials and Minerals

Expansive soil covers large areas in a variety of regions in Jordan which is insufficient to meet the engineering specifications in construction. Phosphogypsum is considered to be the main by-product material which comes from phosphate rock deposits that is available in Jordan. The main purpose of this research is to study the effects of stabilization by phosphogypsum on expansive soil properties. Three Jordanian regions were chosen to represent the expansive soils, Irbid, Madaba, and Abu-Nusire city. Soils were mixed with phosphogypsum at different percentages by dry weight of soil. Some of the representative laboratory tests for swell properties were conducted: …

The Effect Of Artificial Defects On The Fatigue Characteristics Of Aisi 4340 Steel, Yakov B. Unigovski, Dmitry Fishman, Liat Fishman, Liron Shichman, Ofir Moshe, Roni Shneck, Emmanuel Gutman

Journal of Metals, Materials and Minerals

This study examined the fatigue life (Nf) and fatigue limit (FL) of AISI 4340 steel in relation to surface roughness, artificial defects and shot peening. Artificial surface defects on fatigue specimens were obtained by electrical discharge machining (EDM) or by pre-corrosion in 3.5% NaCl and perchloric acid solutions, followed by a fatigue test. The presence of artificial defects of various sizes, taken into account by the area  parameter, led to a significant decrease in fatigue characteristics, while shot peening contributed to their noticeable improvement. Defects resulting from electrochemical corrosion had a much greater negative effect on fatigue …

The Enhancement Of Ethanol Gas Sensors Response Based On Calcium And Zinc Co-Doped Lafeo3/Fe2o3 Thick Film Ceramics Utilizing Yarosite Minerals Extraction As Fe2o3 Precursor, Endi Suhendi, Zeany Luckyta Amanda, Muhamad Taufik Ulhakim, Andhy Setiawan, Dani Gustaman Syarif

Journal of Metals, Materials and Minerals

A gas sensor is a renewed interest of research which has been developed to make a device that can be detected the harmful gases and applied in the several fields of industries. In this paper, we report the modified of gas sensor based thick film ceramic LaFeO3/Fe2O3 by added calcium and zinc co-doping prepared by screen-printed technique. In this work, yarosite mineral was utilized as Fe2O3 precursor. It aims to take the advantages of abundance natural resources in Indonesia to save a cost in gas sensor fabrication. Then, x-ray diffraction (XRD), scanning electron microscopy (SEM) and electrical properties characterization were …

Wollastonite And Talc Reinforced Polypropylene Hybrid Composites: Mechanical, Morphological And Thermal Properties, Naruedee Putfak, Amnouy Larpkasemsuk

Journal of Metals, Materials and Minerals

This study focused on evaluating the mechanical, thermal, and morphological properties of polypropylene (PP) hybrid composites containing two different inorganic mineral fillers, namely wollastonite (WO) and talc. The composites were prepared by melt mixing process using a twin screw extruder and an injection molding machine. All composites contained a constant filler loading at 20 wt% with varying WO/talc weight ratios (20/0, 15/5, 10/10, 5/15, and 0/20). Melt flow index (MFI), mechanical properties (impact strength and tensile properties), heat distortion temperature (HDT) fractured surface morphology, and thermal behaviors of the resulting composites were investigated. The results revealed an enhancement in the …

Effect Of Nitrocarburizing And Argon Admixing On Low Carbon Steel For Component Facility In Radiometallurgical Installation, Erwan Hermawan, Suprapto Suprapto, Usman Sudjadi, Siti Shaleha, Maman Kartaman Ajiriyanto

Journal of Metals, Materials and Minerals

Steel is an important component in the industrialized world with rising growth in world consumption. Steel has wide applications due to its high strength, durability, and cost-effectiveness. This has applications in the nuclear power plant. In Indonesian nuclear industry, low carbon steel is used not only for the fabrication of reactor components but also for the radiometallurgical facilities. However, to avoid the risk of premature failure and enhance the longevity of the components in the service condition, surface modification for the improvement of hardness has been realized. Amongst several methods, surface hardening by following nitrocarburizing has been found to be …

Structural, Magnetic And Transport Properties Of Ca And Sr Doped Lanthanum Manganites, Sunita Keshri, Shailendra Rajput, Sonali Biswas, Leena Joshi, Wojciech Suski, Piotr Wiśniewski

Journal of Metals, Materials and Minerals

This article presents a comparative study for the effect of average A-site cation size on the structural, transport and magnetic properties of Lanthanum manganites. Three polycrystalline colossal magneto-resistive compounds were synthesized using standard solid state reaction method. The electrical resistivity data were analyzed employing standard two-phase model to understand the conduction mechanism. The resistance of polycrystalline ceramic depends on the intragrain resistance (intrinsic resistance) and the intergrain or grain-boundary resistance (extrinsic resistance). The substitution of Sr ions at La-site provides higher magnetic and metal-insulator transitions as compared to Ca ions. The combined substitution of Ca and Sr ions at La-site …

Formation Of Nano-Crystalline Chromium-Zirconium Nitride (Cr-Zr-N) Film Coating By Dc Unbalanced Magnetron Sputtering, Kumpon Leelaruedee, Kattareeya Taweesup, Patama Visuttipitukul

Journal of Metals, Materials and Minerals

This research aimed to improve the properties of chromium nitride (CrN) film coatings by addition of zirconium (Zr) as the third element to form Cr-Zr-N ternary nitride. DC unbalanced magnetron sputtering method was used to form Cr-Zr-N film with various Zr/Zr + Cr atomic ratios.  Mechanical properties, surface morphology and crystal structure of the film were investigated. In the research, Cr-Zr-N film were categorised into 3 types with different Zr amount: low zirconium, (Zr/Zr + Cr = 0.29), medium zirconium (Zr/Zr + Cr = 0.44), and high zirconium (Zr/Zr + Cr = 0.74). All Cr-Zr-N films exhibited nano-crystalline structures with …

Controlled Plasma Tuning Of Mos2 Based Photodetector: From Visible To Ultraviolet Photo Response, Huda Musa Mutlaq, Ali Jabbar Fraih

Journal of Metals, Materials and Minerals

Among diverse family of two-dimensional materials, molybdenum disulfide (MoS2) is one of the most promising materials for optical applications thanks to its tunable optical energy bandgap. In this work, a MoS2 based photodetector is fabricated and its optical properties is investigated. With the help of controlled oxygen plasma bombardment, its photoresponse is tuned from visible to ultraviolet region. The photodetector was subjected to three bombardment times of 60 s, 120 s, and 180 s, and it was observed that 180 s irradiation resulted in a change in the optical response range of the photodetector from visible to ultraviolet. In fact, …

Retaining The High-Temperature Phases Of Rb3h(So4)2 And Rb5h3(So4)4 At Room Temperature, Chatr Panithipongwut Kowalski

Journal of Metals, Materials and Minerals

The attempts to maintain the higher-temperature phases of Rb3H(SO4)2 and Rb5H3(SO4)4 were demonstrated in this work for the first time. The goal was to explore the possibility to utilize solid acids at lower temperatures while keeping the high-temperature phases which connects to the desirable conductivities. Enabling to do so will allow the ease of handling and thermal cycling, and the energy saving in fuel cell applications, and will allow researchers to study the high-temperature properties of solid acids at lower temperatures without the expenses for the in-situ measurements and the accessibility limitations. The four relatively simple methods, which were the …

Poly(Vinyl)Alcohol Film Composited With Carbon Dots From Water Hyacinth Stalks Based On Gamma Irradiation For The Uv Blocking Film, Tanagorn Kwamman, Threeraphat Chutimasakul, Panida Sangangam, Nattamon Puengposop, Kanokorn Wechakorn

Journal of Metals, Materials and Minerals

UV-radiation in the range of 200 nm to 400 nm from sunlight can inhibit the photosynthesis process in plants, while visible light in the range of 400 nm to 700 nm promotes photosynthesis and plant growth. In this work, poly(vinyl)alcohol-carbon dots composite film (PVA-CDs film) was developed as a UV-blocking film due to the excellent optical properties of carbon dots and the film-forming properties of PVA. For the synthesis of carbon dots using gamma irradiation, water hyacinth stalk, an invasive aquatic plant, was used as a carbon source. The result showed that PVA-CDs composite film exhibited excellent UV absorption (200 …

Luminescent Properties Of Polyaniline Capped Mn Doped Zns Quantum Dots, Anju Bala, Rajeev Sehrawat, Anil Kumar Sharma, Pardeep Soni

Journal of Metals, Materials and Minerals

Synthesis of polyaniline capped and Mn doped quantum dots are performed with co-precipitation tech. while structural, optical and morphological properties have been carried out by using Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD) study, photoluminescent (PL), absorption spectroscopy and High-Resolution Transmission Electron Microscopy (HR-TEM). Particles size is nearly 2 nm calculated using XRD analysis and nearly 2.5 nm as estimated from HR-TEM study. FTIR spectra confirm that ZnS and polyaniline interact through S-H vibrations. The absorption spectra analysis reflects the occurrence of blue shift at the peak of absorption along with the enhanced band gap of polyaniline capped ZnS(Mn) …

Towards A Resilient Community: Application Of Advanced Computational Models And Big Data Analytics, Md Golam Rabbani Fahad

All ETDs from UAB

Human-induced climate change has affected the ecosystems and communities across the world in numerous ways. The cascading consequences of climate change have already impacted our infrastructure, human health, energy, and productivity. Climate change likely caused significant changes in weather patterns with devastating effects such as droughts and flooding, sea-level rise, high-intensity rainfall, extreme heat stress, and much more. High fidelity quantification of the associated risk and resiliency to mitigate the impact of extreme weather events has become necessary as communities across the United States are suffering from the repetitive occurrence of natural disasters such as hurricanes, storm surges, and urban …

Comprehensive Review And A Comparison Of Compliance Based Topology Optimization For Simply Supported Beams, Nicholas Yaw Asare Okai

All ETDs from UAB

Traditional structures consume large amounts of raw materials including cementitiouscomposites and steel, which subsequently contribute to the increase in greenhouse gases. Furthermore, the recycling process of construction materials is challenging due to high cost and complex processes that involve crushing of concrete and melting of steel to the required composition. Therefore, it is necessary to optimize the materials used as well as the structural geometry to achieve maximum efficiency (i.e., demand/capacity) and decrease the carbon footprint of structures. The development of sustainable structures and eco-friendly infrastructures aims to minimize materials and energy consumption without impeding the overall performance. Also, an …

Adequately Generating Captions For An Image Using Adaptive And Global Attention Mechanisms., Shravan Kumar Talanki Venkatarathanaiahsetty

Dissertations

Generating description to images is a recent surge and with latest developments in the field of Artificial Intelligence, it can be one of the prominent applications to bridge the gap between Computer vision and Natural language processing fields. In terms of the learning curve, Deep learning has become the main backbone in driving many new applications. Image Captioning is one such application where the usage of Deep learning methods enhanced the performance of the captioning accuracy. The introduction of the Encoder-Decoder framework was a breakthrough in Image captioning. But as the sequences got longer the performance of captions was affected. …

Improving A Network Intrusion Detection System’S Efficiency Using Model-Based Data Augmentation, Vinicius Waterkemper Lodetti

Dissertations

A network intrusion detection system (NIDS) is one important element to mitigate cybersecurity risks, the NIDS allow for detecting anomalies in a network which may be a cyberattack to a corporate network environment. A NIDS can be seen as a classification problem where the ultimate goal is to distinguish between malicious traffic among a majority of benign traffic. Researches on NIDS are often performed using outdated datasets that don’t represent the actual cyberspace. Datasets such as the CICIDS2018 address this gap by being generated from attacks and an infrastructure that reflects an up-to-date scenario.

A problem may arise when machine …

An Evaluation On The Performance Of Code Generated With Webassembly Compilers, Raymond Phelan

Dissertations

WebAssembly is a new technology that is revolutionizing the web. Essentially it is a low-level binary instruction set that can be run on browsers, servers or stand-alone environments. Many programming languages either currently have, or are working on, compilers that will compile the language into WebAssembly. This means that applications written in languages like C++ or Rust can now be run on the web, directly in a browser or other environment. However, as we will highlight in this research, the quality of code generated by the different WebAssembly compilers varies and causes performance issues. This research paper aims to evaluate …

Sensitray: An Integrated Measuring Device For Monitoring Children’S Mealtime Dietary Intake, Hunter S. Guru, Anthony D. Weng, Santosh Pitla, Dipti Dev

Department of Child, Youth, and Family Studies: Faculty Publications

Childhood nutrition establishes consumption norms that affect an individual’s health over the course of their lives. However, early nutrition interventions to establish such norms are uncommon owing to the various inefficiencies associated with current methods of measuring childhood nutrition. Here, we present an IoT measuring device, called the SensiTray, which accurately tracks mealtime intake in a child-friendly and cost-effective fashion. Principal technologies underlying the SensiTray (including mass-sensing technologies, microcontrollers) are identified and analyzed, along with other design choices. Operation of the SensiTray is explained with special attention given to SensiTray software peripherals and algorithms. Preliminary testing consisted of static and …

Requirements Engineering Education Slr Data Set 1988-2020, Marian Daun, Alicia M. Grubb, Bastian Tenbergen

Data

Requirements Engineering (RE) has established itself as a core software engineering discipline. It is well acknowledged that good RE leads to higher quality software and considerably reduces the risk of failure or exceeding budgets of software development projects. Therefore, it is of vital importance to train future software engineers in RE and educate future requirements engineers to adequately manage requirements in various projects. However, to date there exists no central dataset for RE Education articles. To lay the foundation for this important mission, we conducted a systematic literature review. In this dataset, we present 152 articles from the Requirements Engineering …

Signals As Symbols: Applying Normalization Of Deviance To Improve User-Centered Design, Amy Vanschaik

Electronic Theses and Dissertations, 2020-2023

Mistakes can happen in the process of designing and developing interactive digital projects. Sometimes these mistakes negatively impact users' perception and trust of digital interfaces. This research applies the concept of normalization of deviance to identify potential missed opportunities in user-centered design data within the context of a website redesign. By doing this I explore how through observing accidental deviant behaviors or processes we can identify ways to improve the usability and user experience of digital environments. I review the concepts of normalized deviant behavior as addressed by Diane Vaughan in the field of engineering and identify a process for …

Emotional Intelligence And Safety Citizenship Among Army Aviators, Zachary T. Dugger, Bernadette Mccrory

International Journal of Aviation, Aeronautics, and Aerospace

The purpose of this study was to develop an understanding of the relationship between trait emotional intelligence and safety citizenship among United States Army aviators. The study includes analysis of survey responses from 29 individual aviators. Regression analysis was performed to evaluate the relationship between safety citizenship, emotional intelligence, and 15 emotional intelligence facets. Results indicate a significant association (F(1,28) = 15.45; p = 0.001) between safety citizenship and emotional intelligence, and between safety citizenship and 3 emotional intelligence facets: Adaptability (F(1,25) = 23.91; p < 0.001), Self Esteem (F(1,25) = 10.75; p = 0.003), and Optimism (F(1,25) = 8.71; p = …

Methodology For Convergence Of The Training Program With The Professional Activities Of Aviation Specialists, Zair Ziyaevich Shamsiev

International Journal of Aviation, Aeronautics, and Aerospace

The method of developing curricula for training aviation specialists for civil aviation of the Republic of Uzbekistan is analyzed. It is substantiated that it does not sufficiently take into account the labor market requirements for the composition and content of academic disciplines. An overview of foreign experience in bridging the gap between educational programs and the workplace is given. A method based on a statistical analysis of civil aviation regulations is recommended.

Remote Pilot Situational Awareness With Augmented Reality Glasses: An Observational Field Study, Jeffery Coleman, David Thirtyacre

International Journal of Aviation, Aeronautics, and Aerospace

With the use of small unmanned aerial systems (sUAS) proliferating throughout industry and public safety, it is imperative to ensure safety of flight. The Federal Aviation Administration (FAA) published regulations for commercial use of sUAS in 2016 and included the requirement to maintain visual line-of-sight with the aircraft at all times. However, due to the nature of the sUAS ground control stations (GCS), remote pilots time-share between observing the aircraft and interacting with the display on the GCS. Time-sharing between the aircraft and GCS can be seen as similar to the cross-check a pilot uses when flying a manned aircraft. …

Support To Design For Air Traffic Management: An Approach With Agent-Based Modelling And Evolutionary Search, Gabriella Gigante, Roberto Palumbo, Domenico Pascarella, Alessandro Pellegrini, Gabriella Duca, Miquel Angel Piera, Juan José Ramos

International Journal of Aviation, Aeronautics, and Aerospace

This paper presents a methodology to manage the support to design in ATM operations. We propose a workflow for the design of ATM solutions in a performance-based setting. The methodology includes the evaluation of the impact on human behaviour and exploits a combination of different paradigms, such as Agent-Based Modelling and Simulation, and Agent-Based Evolutionary Search. We prove the soundness of the methodology by carrying out a real case study, which is the transition from Direct Routing to Free Routing in the Italian airspace. The validation results exhibit limited errors for the assessment of the performance metrics under evaluation. Furthermore, …

Co2 Reduction Measures In The Aviation Industry: Current Measures And Outlook, Florian Mathys, P. Wild, J. Wang

International Journal of Aviation, Aeronautics, and Aerospace

This article gives a holistic overview of the current CO₂ reduction measures and analyses the effectiveness of measures that are feasible for implementation in the future. To achieve the objectives of the Paris Agreement, the aviation industry needs to implement reduction measures because of its forecasted growth and contribution to global warming. The focus is set on CO₂ reduction measures, categorized in technology, operations, infrastructure/air traffic management (ATM), and market-based measures. The most promising long-term technologies to reduce CO₂ emissions are hydrogen-powered aircrafts and sustainable aviation fuels (SAF). In terms of operations, CO₂ emissions can be …

Quantum Safety Metrics Framework For Commercial Unmanned Aircraft Operators, Tracy L. Lamb, Nathan A. Phillips, Trong Van Nguyen

International Journal of Aviation, Aeronautics, and Aerospace

Commercial unmanned aircraft systems continue to increase in applications and diversity; however, mishaps and accidents erode safety, investment return, and efficiency. Most unmanned aircraft accidents are preceded by leading indicators; the ability to forecast and quantify these may provide increased safety and profitability. This mixed-method research study used a non-experimental parallel convergence approach with multiple instruments, multiple-case study n = 22, and one exemplar case design to develop a quantum safety metric program. This study used a combination of previously validated methods as development instruments, including; the HFACS, STAMP, 'Sierra Scale,' and Accident Prevention Effort equations. The study extended the …

Performance Of The Egnos System In Algeria For Single And Dual Frequency, Lahouaria Tabti, Salem Kahlouche, Belkacem Benadda

International Journal of Aviation, Aeronautics, and Aerospace

EGNOS (European Geostationary Navigation Overlay Service) transmits data for more accurate real time positioning with an integrity message for GNSS navigation satellites, which are in view by RIMS station (Ranging and Integrity Monitoring Stations) extended over a continent.

The purpose of this paper is to analyses the performances of EGNOS V2 single frequency L1 and EGNOS V3 dual frequency L1/L5 without RIMS station in Algeria. During this work, four procedures of flight (APV I, LPV 200, APV II and CAT I) were analyses to determine the optimal performances of the EGNOS system in terms of availability and continuity.

We have …