Engineering Commons^™

Knowledge Gap Analysis For Efficient Form-Finding Of Lightweight Structures, Shorouk Mohamad Khedr, Mohamed Esmat Elattar, Ahmed Eltantawy, Esraa Elazab

Mansoura Engineering Journal

Historically, Performance assessment of temporary structures’ form was substantially dependent on how loads transfer along geometry. Fortunately, the development of tools has enabled designers to explore more design variations as well as testing their feasibility. This study aims to address the knowledge gap between design process, tool contributions and feasibility requirements of temporary structures. This will be achieved through analyzing the evolution of temporary structures’ design approaches including early form finding approaches, geometrical properties dependencies, reflections of both bottom -top and top-bottom approach as well as linking them to material innovations, structural contributions and manual experiments. As a result, the …

Artificial Intelligence In Education: Mathematics Teachers’ Perspectives, Practices And Challenges, Mohammad A. Tashtoush, Yousef Wardat, Rommel Al Ali, Shoeb Saleh

Iraqi Journal for Computer Science and Mathematics

Efforts have been made to include artificial intelligence (AI) in teaching and learning; nevertheless, the successful deployment of new instructional technology depends on the attitudes of the teachers who conduct the lesson. Few scholars have researched teachers' perspectives on AI use due to a general lack of expertise on how it can be used in the classroom, as well as a lack of specific knowledge about what AI-adopted tools would be like. This study investigated mathematics teachers’ perceptions of implemented AI systems and applications in Abu Dhabi Emirate schools. The sample study consists of 580 male and female math teachers …

A 10-Gb/S Single-Loop Half-Rate Dll-Based Clock And Data Recovery Circuit For Forwarded-Clock Wireline Transceivers, Abdallah K. Mohamed, Sameh A. Ibrahim, Mohy Eldin A. Abo-Elsoud

Mansoura Engineering Journal

This paper introduces a 10-Gb/s single-loop, half-rate delay-locked loop (DLL)-based clock and data recovery (CDR) circuit for forwarded-clock (FC) wireline transceivers. The proposed CDR employs a differential ring oscillator (RO) with sub-feedback loops structure for multi-phase clock generation with a single-loop operation. An Alexander phase detector utilizing a flip-flop based on an improved true single-phase clock (TSPC) logic with split outputs is adopted. The proposed DLL-based CDR is an optimized solution in terms of area and power for FC wireline transceivers. The recovered clock exhibits an RMS jitter of 590 fs and a peak-to-peak jitter of 3.8 ps. The circuit …

A Novel Method For The Production Of Pig Iron In “Hadisolb” Company (Industrial-Scale Experiments), El-Sayed A. Rassoul

Mansoura Engineering Journal

The chairman of “Hadisolb” had submitted a memorandum in 1977 in which he claimed that the company will never achieve its designed capacity unless it gets rid of the threatening impurities -high alkalis & MnO- in the blast furnace burden. Meanwhile, the DR steel companies are suffering from the generated accumulated wastes which contain > 67% Fe, zero% alkalis and traces of MnO. The novel idea here is finding the best ratio between El-Gedida ore and the waste material (W.M.). In a previous investigation a series of pilot-scale sintering experiments were performed and it was concluded that the blend containing 70% …

Study The Application Of Different Building Technology Systems Case Study: A Residential Villa In Al-Qassim Region, Ksa, Ahmed Abdelmonteleb M. Ali, Essam S. Almahmoud, Basem O. Elgendy, Azzam I. Aljutayli, Meshal A. Alhrabi, Khattab I. Alyahya

Mansoura Engineering Journal

Buildings are responsible for 39% of global energy-related carbon emissions; 11% come from materials and construction, and 28% come from operational emissions (the energy required to heat, cool, and power). Embodied carbon will contribute an increasing amount to the emissions from new buildings in the future as carbon emissions from building operations continue to decline. This study examined several construction methods and materials to evaluate alternatives for remodeling a residential villa. A villa in the Al-Qassim Region, Buraidah, served as a case study for this research. The methodology employed provided a meticulous appraisal of the building materials and techniques currently …

Analysis Of A Coaxial Magnetic Gear Optimally Designed Using Particle Swarm Optimization, Yasser Kassab, Abdelhady Ghanem, Eid Gouda

Mansoura Engineering Journal

One important key to improve the efficiency of adjustable speed drives is using magnetic gears due to their advantages in comparison to their mechanical counterparts. This paper introduces an analysis study for a magnetic gear optimally designed using the particle swarm optimization algorithm (PSO). Moreover, the results of the PSO-based design are compared with the results of another optimization design process based on a genetic algorithm for the same design parameters and constraints. The proposed magnetic gear topology to be optimized is a radially magnetized coaxial configuration with a surface-mounted permanent magnet array. The gear ratio of the proposed magnetic …

Enhancing The Perception Of Public Urban Spaces Via Place-Making: Martyrs' Square And Selected Locations In El-Gaish Street Case Study, Vert Kamal Ramzy, Nanees Abdel Hamid Mohamed Ali Elsayyad, Lamis Saad El-Din El-Gizawi

Mansoura Engineering Journal

Trust be told that urban spaces have generated a lot of controversy in recent years. The major issues that I will address in this paper are transformations in the urban environment affected by different appearances due to economic and social changes that shape their meaning through human interactions for creating a social life. With the emergence of modern architecture and planning patterns, urban spaces have become the focus of researchers for study and analysis to determine the best destination.

This paper aims to present place-making as an approach to strengthening the perception of public urban spaces and, consequently, its impact …

Estimating Passenger Demand Trends And Passenger Characteristics Along Raml Tram, Hassan Mahdi, Raghdaa Al-Mahdi, Amir Al Samman, Enas Nashed, Noor Elmitiny, Yousra El Gohary, Mohamed Gharieb, Ahmed Elmahyli, Zainab Taha, Abdalla Kandil

Mansoura Engineering Journal

The main objective of this paper is to estimate the current passenger demand trends and passenger perception of Raml Tram usage. In order to undertake this task it was needed to conduct passenger count in addition to undertaking passenger survey along Raml Tram. The main conclusions of this research shows that the maximum number of passengers in summer is 373 compared to the corresponding value which is 420 passengers in school time for Bakous line. similarly, maximum number of passengers in summer is 279 compared to the corresponding value which is 347 passengers in school time for Bakous line. This …

A Chemistry-Transport Model Study For Source Contributions Of Pm2.5 And Its Implications For Southeast Asia Regional Haze Management Policy, Abdul Wahab

Chulalongkorn University Theses and Dissertations (Chula ETD)

PM2.5 pollution is a persistent issue in Southeast Asia. In response, the Association of Southeast Asian Nations (ASEAN) launched the Second Hazefree Roadmap (2023-2030) to alleviate this issue. This roadmap can be an important institutional measure to reduce PM2.5 pollution regionally; however, it largely centres on biomass burning and does not comprehensively tackle other sources. This study aims to quantify the contributions of three key sectors—biomass burning, transport, and industry—to PM2.5 pollution. In addition, for the focus of Thailand, the study assesses transboundary PM2.5 pollution coming into Thailand. We employ the GEOS-Chem chemistry transport model, a widely used global model …

Experimental Investigation Of Self-Mixing Interferometric Technique For Displacement Assessment, Dulanjana Anuhas Egodagamage

Chulalongkorn University Theses and Dissertations (Chula ETD)

The self-mixing interferometric (SMI) technique has proven effective for achieving precise, contactless measurements of submicron displacements. This study aims to further investigate and experimentally assess the capabilities of the SMI technique in displacement sensing. While extensive research has been conducted on the SMI technique for displacement sensing, its performance can still be further explored in scenarios where the target exhibits varying displacement amplitudes and oscillation frequencies. Understanding the limitations and ranges of the SMI technique is crucial for advancing laboratory-based setups into practical applications. An experimental optoelectronic setup was used in this work, employing a semiconductor laser diode module integrated …

Synthesis Of Carbon Nanomaterials From Sale Gas Using Nimo/Mgo Catalyst, Ahsan Khan

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aims to convert greenhouse gases into valuable nanomaterials as a sustainable way to capture and utilize carbon. It examines the synthesis of carbon nanotubes (CNTs) from a methane-ethane mixture (sale gas) with CO₂ added in different reactor setups. A NiMo/MgO catalyst was used to enhance CNT growth. Nickel and molybdenum act as active sites, facilitating to break carbon bonds and supporting CNT formation. The addition of CO₂ promotes dry reforming, which enhances syngas production and influences CNT properties. Factors like gas composition, CO₂ presence, and reactor type affect CNT structure and yield. Extended reaction times improved graphitization, creating …

แนวทางการจัดการฝุ่นละอองขนาดเล็กไม่เกิน 2.5 ไมครอน:กรณีศึกษาพื้นที่เขตดินแดงและเขตปทุมวัน, ณัชภรณ์ ภัทรพงศ์ดิลก

Chulalongkorn University Theses and Dissertations (Chula ETD)

มลพิษทางอากาศโดยเฉพาะจาก PM2.5 เป็นปัญหาสำคัญที่ส่งผลกระทบต่อสุขภาพและคุณภาพชีวิตของมนุษย์ในปัจจุบัน ประเทศไทยเป็นอีกหนึ่งประเทศที่ประสบปัญหาจาก PM2.5 โดยเฉพาะในพื้นที่กรุงเทพมหานครที่มีค่าเกินมาตรฐานที่กำหนดไว้ ซึ่งส่งผลกระทบต่อความมั่นคงของประเทศทั้งในด้านเศรษฐกิจและสังคมอีกทั้งรวมไปถึงส่งผลกระทบต่อสุขภาพของประชาชน ก่อให้เกิดการตายก่อนวัยอันควรในประเทศไทย ประมาณ 50,000 คนต่อปี และกระทบต่อภาพลักษณ์ของกรุงเทพมหานครในฐานะศูนย์กลางการท่องเที่ยว โดยงานวิจัยนี้มีวัตถุประสงค์เพื่อศึกษาแหล่งกำเนิดของมลพิษฝุ่น PM2.5 กรณีศึกษาเขตปทุมวันและเขตดินแดง วิเคราะห์แนวโน้มความสัมพันธ์ระหว่างความเข้มข้นของมลพิษทางอากาศ PM2.5 กับจำนวนของยานยนต์ โดยศึกษาข้อมูลตั้งแต่ปี พ.ศ. 2562-2566 และศึกษามาตรการในการแก้ปัญหา PM2.5 และนอกจากนี้ในงานวิจัยนี้ได้ทำการระบุแหล่งกำเนิดในพื้นที่เขตปทุมวันด้วยวิธี Factor Analysis ผลการศึกษาของการทบทวนเอกสารและผลของการวิเคราะห์ด้วย Factor Analysis พบว่าแหล่งกำเนิดสำคัญที่ส่งผลไปยังมลพิษฝุ่น PM2.5 คือ ฝุ่นถนนและฝุ่นที่ออกมาจากปลายท่อไอเสียยานยนต์ อีกทั้งจำนวนรถที่วิ่งบนถนนในเขตพื้นที่ที่ศึกษาเป็นอีกปัจจัยที่มีผลต่อค่าเฉลี่ย PM2.5 มีรถวิ่งมากยิ่งทำให้จำนวนวันที่ค่าเฉลี่ยมลพิษฝุ่น PM2.5 เกินมาตรฐานมากขึ้น และนอกจากนี้ มาตรการ Work From Home ที่ได้บังคับใช้ในสถานการณ์โควิด-19 สามารถทำให้มลพิษฝุ่น PM2.5 จากแหล่งกำเนิดประเภทยานพาหนะลดลง

Context-Free Grammar Framework For Automatic Shooting Game Enemy Pattern Generation, Nitit Kaweeratanakit

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research proposes a framework for generating enemy patterns for SHMUPs game. It is directly based on a grammar derived from the enemy behavior of existing commercial SHMUPs, and implemented using a new description language called "Enemy Pattern Description Language" (EPDL). EPDL contains all information required to construct the enemy, with no requirement of external data content. The language is human-readable and can be connected to any game engine of choice using an EPDL interpreter. The interpreter itself consists of lexer and recursive descent parser. The results shown in this research is implemented in. "rdnh", a private fork of Touhou …

การพยากรณ์การจ่ายยาของโรงพยาบาลโดยการเรียนรู้ของเครื่องและวิธีการวิเคราะห์เชิงสถิติ, วริศ ปุณณะหิตานนท์

Chulalongkorn University Theses and Dissertations (Chula ETD)

ในปัจจุบันการพยากรณ์การจ่ายยาของโรงพยาบาลถือเป็นหัวใจสำคัญต่อการจัดการคลังยาและการสั่งซื้อยาเป็นอย่างมาก เนื่องจากการพยากรณ์ที่น้อยเกินไปทำให้ยาไม่เพียงพอส่งผลให้เกิดความล่าช้าภายในโรงพยาบาล ในขณะที่การพยากรณ์ที่มากเกินไปทำให้เปลืองพื้นที่ใช้สอยและอาจทำให้ยาเสื่อมสภาพหรือหมดอายุซึ่งส่งผลให้โรงพยาบาลสูญเสียรายได้ การมีแบบจำลองที่สามารถพยากรณ์ปริมาณการจ่ายยาให้ใกล้เคียงกับค่าจริงจะสามารถลดปัญหาการขาดแคลนยาในแต่ละห้องจ่ายยาหรือการที่ห้องจ่ายยามีการกักตุนตัวยาเกินความจำเป็น จากปัญหาที่กล่าวมาข้างต้น โครงงานมหาบัณฑิตนี้จึงถูกจัดทำขึ้นเพื่อนำเสนอแบบจำลองที่จะมาแทนค่าเฉลี่ยเคลื่อนที่แบบทั่วไปซึ่งจะช่วยให้โรงพยาบาลสามารถพยากรณ์ปริมาณการจ่ายยาแต่ละวันได้แม่นยำมากขึ้น โดยจะนำเทคนิคสำหรับพยากรณ์ข้อมูลที่อยู่ในรูปแบบของอนุกรมเวลามาประยุกต์ใช้กับข้อมูลการจ่ายยาย้อนหลังและข้อมูลการนัดหมายแพทย์ย้อนหลัง หลังจากนั้นจะนำผลลัพธ์ที่ได้มาคำนวณค่าเคลาดเคลื่อนด้วยค่าเฉลี่ยของเปอร์เซ็นต์ความคลาดเคลื่อนสัมบูรณ์และค่าเฉลี่ยสมมาตรของเปอร์เซ็นต์ความคลาดเคลื่อนสัมบูรณ์และนำผลที่ได้มาใช้ในการเลือกว่าแบบจำลองไหนให้ค่าคลาดเคลื่อนต่ำที่สุด ผลการทดลองพบว่าแบบจำลองซัพพอร์ตเวกเตอร์รีเกรสชันให้ค่าความคลาดเคลื่อนที่ต่ำกว่าค่าเฉลี่ยเคลื่อนที่แบบทั่วไป แบบจำลองที่ผู้จัดทำโครงงานนำเสนอสามารถนำไปประยุกต์ใช้กับการพยากรณ์การจ่ายยาเพื่อให้แต่ละห้องจ่ายยามียาสำหรับให้บริการในปริมาณที่เพียงพอต่อความต้องการ

การพัฒนาแพลตฟอร์มเมตาเวิร์สแบบเว็บที่มีระบบสนับสนุนปัญญาประดิษฐ์, สืบพงศ์ น้อยศรี

Chulalongkorn University Theses and Dissertations (Chula ETD)

วิทยานิพนธ์ฉบับนี้นำเสนอการพัฒนาต้นแบบแพลตฟอร์มเมตาเวิร์สที่มีขีดความสามารถขั้นพื้นฐานครอบคลุมระบบอวาทาร์ ระบบผู้ใช้หลายราย ระบบสื่อสารตามเวลา ระบบการเชื่อมต่อแชตบอต และฉากโลกเสมือนจริงสามมิติที่เหมือนจริง แพลตฟอร์มที่พัฒนาขึ้นนี้ถูกนำไปใช้ประโยชน์กับหน่วยงานภาคการศึกษาและภาคธุรกิจ ทั้งหน่วยงานภายในจุฬาลงกรณ์มหาวิทยาลัยและสถาบันการศึกษาทั้งในประเทศและระดับนานาชาติ ผลการทดสอบพบว่าระบบทำงานได้ให้ผลสัมฤทธิ์ที่ดีและมีคุณภาพตามความต้องการใช้งานในทางปฏิบัติ สามารถประยุกต์ใช้กับการสร้างห้องเรียนเสมือนออนไลน์ในโลกเสมือนจริง รองรับระบบการสื่อสารระหว่างผู้ใช้ทั้งภาพ เสียง และข้อความ อีกทั้งยังสามารถใช้งานร่วมกับระบบแชตบอตจากภายนอกได้ผ่านระบบเอพีไอที่พัฒนาขึ้น ผลการทดสอบบนระบบคลาวด์ของบริษัท โทรคมนาคมแห่งชาติ จำกัด แสดงให้เห็นว่าระบบสามารถรองรับปริมาณผู้ใช้งานได้ไม่น้อยกว่า 30 รายพร้อมกัน ผลการทดสอบในเชิงประสบการณ์การใช้งานมีระดับความพึงพอใจในเชิงบวก งานวิจัยและพัฒนาจึงให้ประโยชน์และเป็นจุดเริ่มต้นของการประยุกต์ใช้เทคโนโลยีเมตาเวิร์สในวงกว้าง

Experimental Investigation Of Liquid Metal Embrittlement In Hot-Dip Galvanized Structural Steel, Amelia Mcnamee

College of Graduate Studies: Theses & Dissertations

This research investigated the liquid metal embrittlement (LME) of hot-dipped galvanized structural steel. The relationship between stress and failure time was analyzed to evaluate the potential presence of a critical stress threshold beyond which LME may occur. A testing apparatus to induce axial stress was designed and assembled in-house. A36 low carbon steel was tested in this study. Different deadweight loadings were applied to the testing sample along the axial direction. The test temperature was maintained by a programmable furnace while the sample gauge section was submerged in a molten zinc bath. Failure time and total displacement of the steel …

Implementation Of Cavity Vortex Generators To Mitigate Stall And Ice Accretion On The Naca 0012, Eric Pernell

College of Graduate Studies: Theses & Dissertations

With the growing environmental concerns of international aviation carbon emissions are driven by the ever-increasing commercial aviation traffic. This study aims to increase the aerodynamic efficiency of the NACA 0012, by implementing cavity vortex generators with the intent to increase the effective stall angle without a substantial increase of drag. This study is performed with Reynolds Averaged Navier-Stokes (RANS) at a low Reynolds of 5.0E+04 with varying cavity depths along the leading edge. The depths study is placed at 10 percent cord at depths of 3, 5, and 10 percent cord. All cavity vortex generators effectively increased the stall angle …

Environmental Assessment Of Biomass/ Torrefied Biomass And Waste Coal Co-Fired Power Plants With The Incorporation Of Carbon Capture And Storage Technologies, Surja Sarkar

College of Graduate Studies: Theses & Dissertations

Climate change is a worldwide problem that has recently garnered significant attention in recent years. While widespread emissions of greenhouse gases, mainly CO₂, from the combustion of fossil fuels, contribute to global warming, biomass-based heat and electricity generation, on the other hand, is rapidly growing due to its smaller carbon footprint, aiding in attaining the goal of zero carbon emissions. In this study, the environmental assessment of the waste coal and biomass/ torrefied biomass co-fired power plants was completed using the life cycle assessment (LCA) methodology through the performance assessment of the co-fired power plants using the commercial …

Detecting Bearing Race Defects With Inductive Magnetic Reluctance Sensors And Artificial Neural Networks, Collin Daly

College of Graduate Studies: Theses & Dissertations

This work proposes a method of detecting physical damage to bearing races in a rotational assembly by means of magnetic reluctance sensors generating a signal from a rotating gear-tooth wheel. A nominally sinusoidal signal is generated based on the rotation of a gearwheel with regularly spaced voids and lands. Detection is based on the time variance of the signal periodically in relation to the gearwheel and the bearing damage. The purpose of this work is to propose a process to detect and classify bearing race defects using existing sensors and neural networks for hazardous area equipment applications.

Effects Of Additions On The Microstructure, Macrostructure, And Mechanical Properties Of Gray Iron, Evan J. Carter

College of Graduate Studies: Theses & Dissertations

The iron matrix is a major component of the gray iron (GI) microstructure, which is the transformation product of austenite during solidification. It is generally accepted that the structure of the austenite will impact the final grain structure and thus the properties of GI. Refinement of the austenite grain structure has the potential to increase the strength of GI. Knowledge of controlling austenite grain size with common alloy additions in GI is very limited and is investigated in this research. Utilizing the DAAS heat treatment process, the austenite grain boundaries can be retained and observed directly. The observations were correlated …

Cross-Layer Performance Evaluation Of C-V2x, Dhruba Sunuwar

College of Graduate Studies: Theses & Dissertations

The evolution of connected vehicles from a distant futuristic concept to an integral part of daily life is indisputable. Vehicle-to-everything communication (V2X) serves as the cornerstone of this transformation, facilitating seamless interaction among vehicles, infrastructure, pedestrians, and networks. However, evaluating V2X system performance proves intricate due to the dynamic nature of vehicles influenced by mobility factors. To address this complexity, we have developed a specialized system-level simulator expressly for evaluating V2X communication performance. Notably, the simulator encompasses (i) intelligent transportation system (ITS) scenarios integrated into a geographical framework and (ii) the capability to assess cross-layer performance spanning physical (PHY) and …

Numerical Analysis Of A Novel Elastohydrodynamic Seal For Supercritical Co2 Power Cycles With Experimental Verification, Ali Akbor Topu

College of Graduate Studies: Theses & Dissertations

Supercritical carbon dioxide (sCO₂) power cycles outperform conventional thermodynamic cycles regarding the efficiency and equipment footprint because of its unique property of maintaining the density of liquid in the gaseous phase at supercritical state (304.13 K and 7.37 MPa). It has robust use in concentrated solar power, fossil fuel power plants, geothermal electricity, nuclear power, and ship propulsion. To fully utilize sCO2 power cycles, technology readiness must be demonstrated at 10-60 MWe scale, with a working temperature and pressure of 350-700°C, and 10-35 MPa respectively. A crucial obstacle to the full realization of this technology is the absence …

Self-Supervised Contrastive Learning Using Eeg Signals For Mental Stress Assessment, Ugochukwu Uraechu

College of Graduate Studies: Theses & Dissertations

A study is presented to investigate self-supervised contrastive learning (SSCL) models using physiological data obtained from non-invasive wearable sensors for mental stress assessment. The present work involved acquisition of electroencephalography (EEG) signals using wearable sensors, signal preprocessing, data augmentation, and investigation of self-supervised contrastive learning (SSCL) algorithms for multi-class mental stress assessment. Seven volunteers participated in this study executing various mental tasks while wearing an OpenBCI head cap to acquire EEG signals. The acquired EEG signals were preprocessed and utilized for data augmentation in time and frequency domains with different SSCL models. Optimal data augmentation combinations and SSCL models were …

Mathematical Modeling Of Coupled Heat And Mass Transfer In Metal-Hydride Hydrogen Storage Systems, Muhammad Hasnain

College of Graduate Studies: Theses & Dissertations

As a promising clean energy carrier hydrogen has recently gained significant interest, but its efficient and safe storage is a major challenge. Compared to the gaseous state and liquid state, metal hydrides (MH) offer a potentially more effective storage approach for hydrogen. However, the main challenge in this approach is the low thermal conductivity of the MH bed that leads to low heat transfer and ultimately to higher charging and discharging times. The purpose of this work is to develop an in-house comprehensive heat and mass transfer model for hydrogen sorption in MH reactors to simulate the dynamic behavior of …

Machine Learning Based Three-Limb Core-Type Transformer Core Aspect Ratios Identification, Ananta Bijoy Bhadra

College of Graduate Studies: Theses & Dissertations

Power transformers are considered one of the key elements of electric grids. Transient studies include transformer transient analysis which is required for the continuous power supply. However, to perform the transient analysis, the details of the internal structure of the transformer are required which are unobtainable and considered as confidential information. Therefore, the application of topological-based transformer models is limited although the models can accurately represent the transformers. To address this concern, a novel approach utilizing Machine Learning (ML) to identify the core aspect ratios of the three-limb core-type transformer is introduced. The proposed approach, using only the voltage and …

Investigations Of Performance And Emissions Of A Fischer-Tropsch Gtl Sustainable Aerospace Fuel With Lubricity Improver In A Compression Ignition Engine With Butanol Port Fuel Injection, James B. Willis

College of Graduate Studies: Theses & Dissertations

As there is increasing concern over emissions of traditional fossil fuels, as well as the future of continued reliance on this dwindling resource, it is becoming increasingly evident that alternative fuels are a necessity. This research investigates the use of a Fischer-Tropsch fuel from natural gas feedstocks, S8, in an internal combustion research engine with a common rail fuel injection system. This synthetic kerosene fuel has a high DCN of 62, indicating high affinity to autoignition compared to conventional pump diesel (ULSD) at 48 DCN. However, due to the process by which it is produced, this fuel lacks the necessary …

Investigation Of Mechanically Fatigue Low-Frequency Energy Harvesting Effects On Isotropic Materials, Daniel J. Meade

College of Graduate Studies: Theses & Dissertations

This research project reports an exploratory investigation of energy harvesting effect on isotropic material that goes through low frequency mechanical fatigue. Energy harvesting is a growing field of study that can recycle ambient energy back into a system that would otherwise be lost. This is a significantly useful method for the ongoing energy crisis and provides an alternate route to design and upgrade systems to be more efficient and last longer than current system designs. However, it is time to investigate if there is any effect vibration-based energy harvesting has on the structure from which energy is being harvested. To …

Computational Analysis Of A Naca 0012 Straight Wing At Various Reynolds Numbers Approaching Stall, John E. Crowe Iii

College of Graduate Studies: Theses & Dissertations

As the capabilities and power of computational resources improve with each passing year, the implementation of simulation in the field of aerospace engineering also increases due to its increased efficiency, as it allows for reducing both time and resources. In this study, a computational method is created and tested for determining and visualizing the effect of increasing flow velocity on a NACA 0012 3D wing as it approaches and reaches stall. For this study, the flow over a NACA 0012 3D wing is simulated using a Reynolds-averaged Navier Stokes simulation at angles of attack of 6, 8, 10, 12, and …

Resonant Ultrasound Spectroscopy(Rus) For Material Characterization Of Metal Am Parts, Malik Marks

College of Graduate Studies: Theses & Dissertations

Additive manufacturing (AM) has revolutionized the manufacturing industry by offering flexibility, customization, and rapid prototyping capabilities. However, ensuring the quality and reliability of AM parts remains a significant challenge due to variations in material properties and process parameters. The NDE method used in this study is Resonant Ultrasound Spectroscopy (RUS). This method was used to evaluate and understand its ability to detect internal voids and defects. Dog-bone samples were made using the 316L stainless steel alloy which were fabricated by powder bed fusion (PBF) AM technique at different processing conditions and post processing conditions. These samples were tested to find …

Closing Dichloramine Decomposition Nitrogen And Oxygen Mass Balances: Relative Importance Of End-Products From The Reactive Nitrogen Species Pathway, Huong T. Pham, David G. Wahman, Julian L. Fairey

Civil Engineering Faculty Publications and Presentations

In drinking water chloramination, monochloramine autodecomposition occurs in the presence of excess free ammonia through dichloramine, the decay of which was implicated in N-nitrosodimethylamine (NDMA) formation by (i) dichloramine hydrolysis to nitroxyl which reacts with itself to nitrous oxide (N₂O), (ii) nitroxyl reaction with dissolved oxygen (DO) to peroxynitrite or mono/dichloramine to nitrogen gas (N₂), and (iii) peroxynitrite reaction with total dimethylamine (TOTDMA) to NDMA or decomposition to nitrite/nitrate. Here, the yields of nitrogen and oxygen-containing end-products were quantified at pH 9 from NHCl₂ decomposition at 200, 400, or 800 μeq Cl₂·L …