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2020

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Full-Text Articles in Engineering

การสังเคราะห์โบรอนคาร์ไบด์จากรังไหมและกรดบอริก, กานต์ชนก ภูผาทอง Jan 2020

การสังเคราะห์โบรอนคาร์ไบด์จากรังไหมและกรดบอริก, กานต์ชนก ภูผาทอง

Chulalongkorn University Theses and Dissertations (Chula ETD)

โบรอนคาร์ไบด์เป็นวัสดุที่ได้รับความสนใจอย่างแพร่หลาย เนื่องจากมีความแข็งสูงประกอบกับมีสมบัติเชิงกลและทางกายภาพที่เป็นเลิศ จึงถูกนำไปใช้งานที่ต้องการความทนทานในสภาวะพิเศษหลากหลายด้าน ในงานวิจัยนี้ ผู้วิจัยได้มีความพยายามที่จะสังเคราะห์โบรอนคาร์ไบด์ที่อุณหภูมิต่ำ จากรังไหมและกรดบอริก เนื่องจากรังไหมมีหมู่ฟังก์ชันไฮดรอกซิลภายในโครงสร้าง สามารถสร้างพันธะ B-O-C ระหว่างกระบวนการเตรียมสารผสมตั้งต้นร่วมกับกรดบอริก รังไหมจะถูกจุ่มแช่ในสารละลายกรดบอริก จากนั้นนำไปสังเคราะห์โดยผ่านหรือไม่ผ่านขั้นตอนแคลไซน์ ผลิตภัณฑ์จากการสังเคราะห์ได้ถูกนำมาตรวจสอบองค์ประกอบเฟสด้วยเทคนิคการเลี้ยวเบนของรังสีเอ็กซ์ จากการทดลองปรับเปลี่ยนตัวแปรต่างๆในกระบวนการ พบว่า การจุ่มแช่รังไหม 1 กรัม ในสารละลายที่เตรียมกรดบอริก 2 และ 4 กรัม ในน้ำปราศจากไอออน 150 มิลลิลิตร เป็นเวลา 4 ชั่วโมง ณ อุณหภูมิห้อง เมื่อผ่านการอบและสังเคราะห์ที่อุณหภูมิ 1450 องศาเซลเซียส เป็นเวลา 5 ชั่วโมง ในบรรยากาศก๊าซอาร์กอน องค์ประกอบเฟสของผลิตภัณฑ์ประกอบด้วยโบรอนคาร์ไบด์ โดยมีคาร์บอนปรากฏเป็นเฟสหลักอยู่ในระบบ เมื่อลดอุณหภูมิการสังเคราะห์เป็น 1350 องศาเซลเซียส ไม่พบโบรอนคาร์ไบด์ในองค์ประกอบเฟสของผลิตภัณฑ์ นอกจากนี้ เมื่อนำกระบวนการไฮโดรเทอร์มัลที่ 180 องศาเซลเซียส 4 ชั่วโมง มาใช้ร่วมในการสังเคราะห์ พบว่าไม่สามารถพัฒนาการเกิดเฟสโบรอนคาร์ไบด์ให้เพิ่มขึ้น อย่างไรก็ตาม งานวิจัยในส่วนนี้ยังคงต้องการการศึกษาทดลองเพิ่มเติมเพื่อยืนยันผล

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การสังเคราะห์โบรอนคาร์ไบด์จากไตรเมทิลบอเรตและแบคทีเรียเซลลูโลส, รณภูมิ ไชยตระการกิจ Jan 2020

การสังเคราะห์โบรอนคาร์ไบด์จากไตรเมทิลบอเรตและแบคทีเรียเซลลูโลส, รณภูมิ ไชยตระการกิจ

Chulalongkorn University Theses and Dissertations (Chula ETD)

โบรอนคาร์ไบด์เป็นวัสดุเซรามิกที่มีความแข็งสูงมาก และมีสมบัติเชิงกลยอดเยี่ยมที่อุณหภูมิสูง งานวิจัยนี้มีความพยายามที่จะสังเคราะห์โบรอนคาร์ไบด์ที่อุณหภูมิต่ำด้วยวิธีการคาร์โบเทอร์มิกรีดันชัน โดยใช้สารตั้งต้นได้แก่ ไตรเมทิลบอเรตเป็นแหล่งโบรอนและแบคทีเรียเซลลูโลสเป็นแหล่งคาร์บอน จากการตรวจสอบหมู่ฟังก์ชันของสารผสมตั้งต้น พบพันธะ B-O-C ซึ่งเอื้อต่อการเกิดเฟสโบรอนคาร์ไบด์ในผลิตภัณฑ์ จากการตรวจสอบองค์ประกอบเฟสในผลิตภัณฑ์ที่เตรียมสารผสมตั้งต้นโดยใช้น้ำปราศจากไอออนเป็นตัวทำละลายผ่านการสังเคราะห์ที่อุณหภูมิ 1450 องศาเซลเซียส เป็นเวลา 5 ชั่วโมง ในบรรยากาศก๊าซอาร์กอน โดยไม่ผ่านขั้นตอนการเผาแคลไซน์ พบว่ามีโบรอนคาร์ไบด์เป็นเฟสหลัก และยังคงพบคาร์บอนเป็นมลทินในผลิตภัณฑ์ โครงสร้างจุลภาคของผลิตภัณฑ์ที่สังเคราะห์ได้ประกอบด้วยผลึกโบรอนคาร์ไบด์รูปร่างหลายเหลี่ยมขนาด 1-5 ไมครอน เป็นส่วนใหญ่ โดยมีอนุภาครูปร่างคล้ายแบคทีเรียเซลลูโลสที่ยังไม่ได้ทำปฏิกิริยากระจายในโครงสร้าง

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Electrotransfer Of Il-15/Il-15rα Complex For The Treatment Of Established Melanoma, Shawna A. Shirley, Cathryn G. Lundberg, Richard Heller Jan 2020

Electrotransfer Of Il-15/Il-15rα Complex For The Treatment Of Established Melanoma, Shawna A. Shirley, Cathryn G. Lundberg, Richard Heller

Bioelectrics Publications

Gene electrotransfer (GET) is a safe, reliable, and effective method of delivering plasmid DNA (pDNA) to solid tumors. GET has been previously used to deliver interleukin-15 (IL-15) to mouse melanoma, resulting in long-term tumor regression and the survival of a percentage of treated animals after challenge. To enhance this effect, we evaluated modulating the expression levels of IL-15 and co-expressing its receptor, IL-15Rα. GET was used to deliver plasmids encoding IL-15 and IL-15Rα to established B16.F10 tumors on days 0, 4, and 7. Two delivery protocols that yielded different expression profiles were utilized. Mice that were tumor-free for 50 days …

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Grain Boundary Defect Passivation Of Mixed Cation Perovskite Solar Cell To Improve Device Performance, Sheikh Ifatur Rahman Jan 2020

Grain Boundary Defect Passivation Of Mixed Cation Perovskite Solar Cell To Improve Device Performance, Sheikh Ifatur Rahman

Electronic Theses and Dissertations

Rigorous research on perovskite solar cell for more than ten years all over the world has led the rapid development of perovskite technology giving us device efficiency of 25.2%, surpassing the performance of traditional thin-film solar technologies on small scale devices (<1cm2). Perovskite material has excellent electronic and optical properties making it greatly suitable for PV application. The device fabrication process being simple with low cost and solution processability has led the researchers to visualize high efficiency scalable devices. Due to solution process fabrication method the defects in the materials causes the devices perform less than anticipated. These …

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Technology Business Leaders' Strategies To Increase Employees' Engagement, Desmond J. L. Browne Jan 2020

Technology Business Leaders' Strategies To Increase Employees' Engagement, Desmond J. L. Browne

Walden Dissertations and Doctoral Studies

AbstractEmployee disengagement is costly and reduces an organization's ability to meet its full potential to produce business results. Technology business leaders who have engaged employees can positively alter the company's rapid transformation to be more competitive. Grounded by the social exchange theory, the purpose of this qualitative single case study was to explore strategies 6 technology leaders in the Atlanta metropolitan area use to engage employees. Data were collected through semistructured interviews and company documents. Data were analyzed using Yin's 5-step data analysis process. Three themes emerged: communicate with transparency, provide offerings for training and rewards, and identify and implement …

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Editorial For The Special Issue On Micro/Nano-Chip Electrokinetics, Volume Iii, Shizhi Qian, Xiangchun Xuan Jan 2020

Editorial For The Special Issue On Micro/Nano-Chip Electrokinetics, Volume Iii, Shizhi Qian, Xiangchun Xuan

Mechanical & Aerospace Engineering Faculty Publications

No abstract provided.

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Tracing Sources Of Natural Organic Matter, Trihalomethanes And Metals In Groundwater From A Karst Region, Connie O'Driscoll, Eoin Mcgillicuddy, Peter Croot, Pamela Bartley, John Mcmyler, Jerome Sheahan, Liam Morrison Jan 2020

Tracing Sources Of Natural Organic Matter, Trihalomethanes And Metals In Groundwater From A Karst Region, Connie O'Driscoll, Eoin Mcgillicuddy, Peter Croot, Pamela Bartley, John Mcmyler, Jerome Sheahan, Liam Morrison

Articles

Groundwater offers an important source for drinking water around the world; however, groundwater quality is under increasing pressure and is particularly vulnerable in karst areas. Total organic carbon (TOC) is significantly related to groundwater quality and when not removed by water treatment processes can give rise to the formation of disinfection by-products trihalomethanes (THMs) above the level of compliance. This study investigated the source of organic matter giving rise to the THM exceedances in a groundwater supply in a karst area. Results highlighted that source water for this groundwater supply was prone to surface water infiltration linked to rainfall events; …

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A Direct Data-Cluster Analysis Method Based On Neutrosophic Set Implication, Florentin Smarandache, Sudan Jha, Gyanendra Prasad Joshi, Lewis Nkenyereya, Dae Wan Kim Jan 2020

A Direct Data-Cluster Analysis Method Based On Neutrosophic Set Implication, Florentin Smarandache, Sudan Jha, Gyanendra Prasad Joshi, Lewis Nkenyereya, Dae Wan Kim

Branch Mathematics and Statistics Faculty and Staff Publications

Raw data are classified using clustering techniques in a reasonable manner to create disjoint clusters. A lot of clustering algorithms based on specific parameters have been proposed to access a high volume of datasets. This paper focuses on cluster analysis based on neutrosophic set implication, i.e., a k-means algorithm with a threshold-based clustering technique. This algorithm addresses the shortcomings of the k-means clustering algorithm by overcoming the limitations of the threshold-based clustering algorithm. To evaluate the validity of the proposed method, several validity measures and validity indices are applied to the Iris dataset (from the University of California, Irvine, Machine …

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A Comparative Analysis Of Reinforcement Learning Applied To Task-Space Reaching With A Robotic Manipulator With And Without Gravity Compensation, Jonathan Fugal Jan 2020

A Comparative Analysis Of Reinforcement Learning Applied To Task-Space Reaching With A Robotic Manipulator With And Without Gravity Compensation, Jonathan Fugal

Theses and Dissertations--Electrical and Computer Engineering

Advances in computing power in recent years have facilitated developments in autonomous robotic systems. These robotic systems can be used in prosthetic limbs, wearhouse packaging and sorting, assembly line production, as well as many other applications. Designing these autonomous systems typically requires robotic system and world models (for classical control based strategies) or time consuming and computationally expensive training (for learning based strategies). Often these requirements are difficult to fulfill. There are ways to combine classical control and learning based strategies that can mitigate both requirements. One of these ways is to use a gravity compensated torque control with reinforcement …

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Performance Enhancement And Prediction Of Composite Materials With Embedded Electrospun Piezoelectric Sensors, Rahman Jani Mazed, Muthu Ram Prabhu Elenchezhian, Vamsee Vadlamudi, Md Riaz Uddin Ahmed, Rassel Raihan, Kenneth Reifsnider Jan 2020

Performance Enhancement And Prediction Of Composite Materials With Embedded Electrospun Piezoelectric Sensors, Rahman Jani Mazed, Muthu Ram Prabhu Elenchezhian, Vamsee Vadlamudi, Md Riaz Uddin Ahmed, Rassel Raihan, Kenneth Reifsnider

Institute of Predictive Performance Methodologies (IPPM-UTARI)-Archive

In today’s world, continuous fiber reinforced composite materials are extensively used in the aerospace, automotive and other structural industries. Since the applications of such fibers demand for a high safety rating, it is of utmost importance for engineers who design such materials to analyze its safety. When cracks are developed in such materials, the mechanical, electrical, and thermal properties also get altered as a function of the cracks. Previous studies have shown that changes in electrical properties can be directly correlated with the development of cracks in the material which can then be used to predict the remaining life of …

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Stel Benchmark Verb Alignment To Cognitive, Affective, And Psychomotor Domains, T. Shown, Philip A. Reed Jan 2020

Stel Benchmark Verb Alignment To Cognitive, Affective, And Psychomotor Domains, T. Shown, Philip A. Reed

STEMPS Faculty Publications

(First paragraph) Curriculum developers and classroom teachers often need to make sure they are teaching and assessing students at the appropriate levels of the cognitive, affective, and psychomotor domains. The STEL benchmarks are written with active verbs to target different levels of these domains. In addition, curriculum developers and classroom teachers want to know whether the benchmarks are at the factual, conceptual, procedural, or metacognitive level of knowledge. The second resource being provided on ITEEA’s interactive STEL website will identify these factors for all 142 STEL benchmarks. This tool was developed to help insure the alignment of the three domains …

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Logistic Function Based Nonlinear Modeling And Circuit Analysis Of The Bipolar Vacancy Migration Memristor, Isaac P. Abraham Jan 2020

Logistic Function Based Nonlinear Modeling And Circuit Analysis Of The Bipolar Vacancy Migration Memristor, Isaac P. Abraham

Browse all Theses and Dissertations

Memristor is an acronym for memory resistor. Memristors promise to be building blocks for high density memory and analog computation. Hewlett Packard’s announcement in 2008 of having fabricated a memristor on an integrated circuit scale has created a tangible excitement in this field. Understanding and exploiting the full potential of these devices requires good compact models. Symbolic modeling provides a balance between achieving accurate empirical fit and generating closed form expressions. This dissertation simplifies the transport equation into a variable coefficient advection equation, very similar to a Burgers’ equation traditionally used in fluid dynamics. The Burgers’-like model reveals the dual …

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Joint Shelf Design And Shelf Space Allocation Problem For Retailers, Hakan Gecili Jan 2020

Joint Shelf Design And Shelf Space Allocation Problem For Retailers, Hakan Gecili

Browse all Theses and Dissertations

Although the retail business has been exploring innovative ways to engage shoppers, the COVID-19 pandemic has sped up their effort. Because of its unique benefits, physical stores will continue to remain an integral part of the overall retail business. However, to stay competitive, retailers will be forced to effectively utilize their available space in physical store (and even reduce it if need be), while offering a reasonably large assortment of products on their shelves. For many such retailers, the design of planograms – visual representation of products on shelves – is still driven by prior experience and intuition. Further, existing …

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Topological Analysis Of Averaged Sentence Embeddings, Wesley J. Holmes Jan 2020

Topological Analysis Of Averaged Sentence Embeddings, Wesley J. Holmes

Browse all Theses and Dissertations

Sentence embeddings are frequently generated by using complex, pretrained models that were trained on a very general corpus of data. This thesis explores a potential alternative method for generating high-quality sentence embeddings for highly specialized corpora in an efficient manner. A framework for visualizing and analyzing sentence embeddings is developed to help assess the quality of sentence embeddings for a highly specialized corpus of documents related to the 2019 coronavirus epidemic. A Topological Data Analysis (TDA) technique is explored as an alternative method for grouping embeddings for document clustering and topic modeling tasks and is compared to a simple clustering …

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Design Of A Novel Wearable Ultrasound Vest For Autonomous Monitoring Of The Heart Using Machine Learning, Garrett G. Goodman Jan 2020

Design Of A Novel Wearable Ultrasound Vest For Autonomous Monitoring Of The Heart Using Machine Learning, Garrett G. Goodman

Browse all Theses and Dissertations

As the population of older individuals increases worldwide, the number of people with cardiovascular issues and diseases is also increasing. The rate at which individuals in the United States of America and worldwide that succumb to Cardiovascular Disease (CVD) is rising as well. Approximately 2,303 Americans die to some form of CVD per day according to the American Heart Association. Furthermore, the Center for Disease Control and Prevention states that 647,000 Americans die yearly due to some form of CVD, which equates to one person every 37 seconds. Finally, the World Health Organization reports that the number one cause of …

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A First Principles Study Of Pipe Diffusion In Nickel, Luke J. Wirth Jan 2020

A First Principles Study Of Pipe Diffusion In Nickel, Luke J. Wirth

Browse all Theses and Dissertations

Vacancy-mediated diffusion along dislocations, often referred to as pipe diffusion, can contribute to creep deformation of metals in many engineering applications. This process is studied along an a/2⟨1 -1 0⟩ screw dislocation in fcc Ni using a density functional theory approach. An accurate geometrical configuration of the screw dislocation core, dissociated into Shockley partial dislocations and separated by a stacking fault, was previously derived using a lattice Green's function technique. Activation energies and frequencies are calculated for atom-vacancy exchanges that contribute to diffusion around and along one of the partial cores. This analysis reveals the significant role of the sites …

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The Steady-State Analysis Of The Non-Isolated And Isolated Type Sepic Pwm Dc-Dc Converters For Ccm, Anuroop Reddy Dasari Jan 2020

The Steady-State Analysis Of The Non-Isolated And Isolated Type Sepic Pwm Dc-Dc Converters For Ccm, Anuroop Reddy Dasari

Browse all Theses and Dissertations

The purpose of this thesis is to develop the theory for analysing and designing the non-isolated and isolated type of SEPIC converters for continuous conduction mode (CCM). The non-isolated converter has single output. The isolated converter considered has two cases: single output and multi-output. The principle of operation of each circuit is explained during different time intervals of the switching cycle. The analytical expressions for various characteristics of the circuits are derived, such as: MV DC and MIDC of the lossless and lossy converter; average and peak-to-peak currents through the inductors, primary and secondary windings of the transformer; average and …

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Understanding Depression During The Covid-19 Pandemic Through Social Media Data, Nusrat Armin Jan 2020

Understanding Depression During The Covid-19 Pandemic Through Social Media Data, Nusrat Armin

Electronic Theses and Dissertations

The COVID-19 pandemic has dramatically affected peoples’ daily lives all over theworld - physically, economically, and emotionally. Due to the virus, many people have died, and many hospitalized. A record number of people have lost their job, and many businesses have closed. The global economy is at risk. People are facing new realities of their lives. Studies have shown that the level of depression is three times higher than before this pandemic. Previous studies have shown that people use social media to express their emotions and feelings. The purpose of this study is to understand the depression during this COVID-19 …

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Energy Forensics Analysis, Rupa Das Jan 2020

Energy Forensics Analysis, Rupa Das

Graduate Theses, Dissertations, and Problem Reports (ETD)

The energy consumed by a building can reveal information about the occupants and their activities inside the building. This could be utilized by industries and law enforcement agencies for commercial or legal purposes. Utility data from Smart Meter (SM) readings can reveal detailed information that could be mapped to foretell resident occupancy and type of appliance usage over desired time intervals. However, obtaining SM data in the United States is laborious and subjected to legal and procedural constraints. This research develops a user-driven simulation tool with realistic data options and assumptions of potential human behavior to determine energy usage patterns …

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Dynamic Study Of Mo/Zsm-5 Catalyst For Ch4 Dehydroadomation, Hadi Yahya Almusawa Jan 2020

Dynamic Study Of Mo/Zsm-5 Catalyst For Ch4 Dehydroadomation, Hadi Yahya Almusawa

Graduate Theses, Dissertations, and Problem Reports (ETD)

Methane dehydroaromatization (CH4-MDA) is a highly promising venture for natural gas utilization/exploitation, i.e., direct conversion of methane (CH4) to liquid aromatics (benzene) and hydrogen. This process is a catalytic reaction and therefore, is subject to all the advantages and constraints of catalysis. This study discussed the structure and reactivity of Mo/ZSM-5 zeolite catalysts and their effect on the active conversion of methane to valuable aromatic products such as benzene: 1) The preparation and characterization of Mo/ZSM-5, which are crucial steps in any catalytic reaction process since a better performing catalyst consequently leads to better outcomes; 2) …

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Comparative Study Of Model-Based And Learning-Based Disparity Map Fusion Methods, Douglas E. Kerr Jr. Jan 2020

Comparative Study Of Model-Based And Learning-Based Disparity Map Fusion Methods, Douglas E. Kerr Jr.

Graduate Theses, Dissertations, and Problem Reports (ETD)

Creating an accurate depth map has several, valuable applications including augmented/virtual reality, autonomous navigation, indoor/outdoor mapping, object segmentation, and aerial topography. Current hardware solutions for precise 3D scanning are relatively expensive. To combat hardware costs, software alternatives based on stereoscopic images have previously been proposed. However, software solutions are less accurate than hardware solutions, such as laser scanning, and are subject to a variety of irregularities. Notably, disparity maps generated from stereo images typically fall short in cases of occlusion, near object boundaries, and on repetitive texture regions or texture-less regions. Several post-processing methods are examined in an effort to …

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Tunable-Focus Liquid Lens Through Charge Injection, Shizhi Qian, Wenxiang Shi, Huai Zheng, Zhaohui Liu Jan 2020

Tunable-Focus Liquid Lens Through Charge Injection, Shizhi Qian, Wenxiang Shi, Huai Zheng, Zhaohui Liu

Mechanical & Aerospace Engineering Faculty Publications

Liquid lenses are the simplest and cheapest optical lenses, and various studies have been conducted to develop tunable-focus liquid lenses. In this study, a simple and easily implemented method for achieving tunable-focus liquid lenses was proposed and experimentally validated. In this method, charges induced by a corona discharge in the air were injected into dielectric liquid, resulting in “electropressure” at the interface between the air and the liquid. Through a 3D-printed U-tube structure, a tunable-focus liquid lens was fabricated and tested. Depending on the voltage, the focus of the liquid lens can be adjusted in large ranges (−∞ to −9 …

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Toward Adjoint-Based Aeroacoustic Optimization For Propeller And Rotorcraft Applications, Ramiz Ö. Içke, Oktay Baysal, Andy Moy, Leonard V. Lopes, Beckett Zhou, Boris Diskin Jan 2020

Toward Adjoint-Based Aeroacoustic Optimization For Propeller And Rotorcraft Applications, Ramiz Ö. Içke, Oktay Baysal, Andy Moy, Leonard V. Lopes, Beckett Zhou, Boris Diskin

Mechanical & Aerospace Engineering Faculty Publications

The goal of the present project is to build a multidisciplinary, rapid, robust, and accurate computational tool to optimize wing-mounted propeller designs. The full Farassat’s formulation F1A for aeroacoustic analysis is implemented in the open-source software SU2. This extension enables the prediction of far-field noise generated by moving sources. The formulation is verified, for a stationary and rotating sphere in a wind tunnel and for a tiltrotor in forward flight, by comparing the acoustic predictions of SU2 with the predictions computed by NASA’s aeroacoustics code ANOPP2. The algorithmic differentiation capability of SU2 provides discretely consistent, adjoint-based sensitivity analysis for this …

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Parametric Study Of A Turbojet Engine With Auxiliary Bypass Combustion- The Turboaux Engine, Kaleab Fetahi, Sharanabasaweshwara A. Asundi, Arthur C. Taylor, Adem H. Ibrahim, Syed Firasat Ali Jan 2020

Parametric Study Of A Turbojet Engine With Auxiliary Bypass Combustion- The Turboaux Engine, Kaleab Fetahi, Sharanabasaweshwara A. Asundi, Arthur C. Taylor, Adem H. Ibrahim, Syed Firasat Ali

Mechanical & Aerospace Engineering Faculty Publications

A parametric study of a novel turbojet engine with an auxiliary combustion chamber, nicknamed the TurboAux engine is presented. The TurboAux engine is conceived as an extension of a turbojet engine with an auxiliary bypass annular combustion chamber around the core stream. The study presented in this article is motivated by the need to facilitate clean secondary burning of fuel at temperatures higher than conventionally realized from air exiting the low-pressure compressor. The parametric study is initiated by performing a simple optimization analysis to identify optimal ‘fan’ pressure ratios for a series of conventional low-bypass turbofan engines with varying bypass …

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Assessment And Applications Of The Conversion Of Chemical Energy To Mechanical Energy Using Model Rocket Engines, Hüseyin Sarper, Nebojsa I. Jaksic, Ben J. Stuart, Karina Arcaute Jan 2020

Assessment And Applications Of The Conversion Of Chemical Energy To Mechanical Energy Using Model Rocket Engines, Hüseyin Sarper, Nebojsa I. Jaksic, Ben J. Stuart, Karina Arcaute

Mechanical & Aerospace Engineering Faculty Publications

To provide the first-year engineering students with a hands-on experience in an engineering application using both chemistry and physics, this team project uses a set of chemical and physical energy concepts and MS Excel based analysis. The main objective of the project is to calculate how much of the potential maximum possible chemical energy is converted into propulsion when using model rocket engines with solid fuel. The secondary objective is to determine the effects of increasing conversion rates on the performance of a model rocket. The solid fuel or propellant used in common model rocket engines is black powder. Compared …

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Glue-Infused Rotating Nanofibers Net (Gronnet) For Capturing Space Debris- A Novel Debris Capturing System, Sneha M. Raibagi, Prithvi S.J. Monteiro, Rashmi K. Pallam, Amogh Anantha Murthy, Amit G. Gadag, Sharanabasaweshwara Asundi, Oleksandr Kravchenko Jan 2020

Glue-Infused Rotating Nanofibers Net (Gronnet) For Capturing Space Debris- A Novel Debris Capturing System, Sneha M. Raibagi, Prithvi S.J. Monteiro, Rashmi K. Pallam, Amogh Anantha Murthy, Amit G. Gadag, Sharanabasaweshwara Asundi, Oleksandr Kravchenko

Mechanical & Aerospace Engineering Faculty Publications

It is evident that space debris is a growing concern, particularly in the low altitude Earth orbits, and if not addressed in time, may have a drastic socio-economic impact on civilization. This paper describes the Glue-infused Rotating Nanofibers Net (GRoNNet), a novel debris capturing system for pico/nano/micro-satellites (PNMSats). GRoNNet is designed as a modular, cost-effective system with the capability to capture target debris in multiple attempts and expedite its re-entry by attaching a debris mitigation system. It may be best described by comparing it with a chameleon’s tongue but several hundreds/thousands of them infused with a thick honey-like viscous adhesive …

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Understanding The Demands And Resources For Academic Success Of Second-Career Undergraduate Engineering Students As Compared To Traditional Undergraduate And Graduate Engineering Students, Oleksandr Kravchenko, Konstantin Cigularov, Phillip J. Dillulio Jan 2020

Understanding The Demands And Resources For Academic Success Of Second-Career Undergraduate Engineering Students As Compared To Traditional Undergraduate And Graduate Engineering Students, Oleksandr Kravchenko, Konstantin Cigularov, Phillip J. Dillulio

Mechanical & Aerospace Engineering Faculty Publications

Environmental and personal demands and resources can significantly affect the academic success and degree persistence rates of engineering students. The present study adopted a demands and resources conceptual framework to identify and compare the most critical demands and resources, both internal and external, for academic success and well-being of traditional and second career undergraduate students, as well as graduate engineering students. Participants in the current study were 342 engineering students, who completed an anonymous, online survey with 57 items for a 17.1% response rate. They were predominantly white (63.4%) and male (73.4%), with an average age of 25.85 years old …

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Minding Morality: Ethical Artificial Societies For Public Policy Modeling, Saikou Y. Diallo, F. Leron Shults, Wesley J. Wildman Jan 2020

Minding Morality: Ethical Artificial Societies For Public Policy Modeling, Saikou Y. Diallo, F. Leron Shults, Wesley J. Wildman

VMASC Publications

Public policies are designed to have an impact on particular societies, yet policy-oriented computer models and simulations often focus more on articulating the policies to be applied than on realistically rendering the cultural dynamics of the target society. This approach can lead to policy assessments that ignore crucial social contextual factors. For example, by leaving out distinctive moral and normative dimensions of cultural contexts in artificial societies, estimations of downstream policy effectiveness fail to account for dynamics that are fundamental in human life and central to many public policy challenges. In this paper, we supply evidence that incorporating morally salient …

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Defects Analysis Of Seat Belt Tensioner Cast Body, Artur Soroczński, Piotr Czyżewski, Krzysztof Rechowicz Jan 2020

Defects Analysis Of Seat Belt Tensioner Cast Body, Artur Soroczński, Piotr Czyżewski, Krzysztof Rechowicz

VMASC Publications

The article presents an analysis of the implementation of a selected element of the traveler safety system used in road transport. The results of metallographic tests were presented, and the state of stress introduced to the casting by means of forming the element by means of plastic forming was analyzed. An analysis of the manufacturing process was carried out indicating the risks that may lead to cracks in the material structure. Possible causes of founding defects were pointed out and possible technological solutions were pointed out in order to avoid them.

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Arsenic Exposure And Methylation Efficiency In Relation To Oxidative Stress In Semiconductor Workers, Chih-Hong Pan, Ching-Yu Lin, Ching-Huang Lai, Hueiwang Anna Jeng Jan 2020

Arsenic Exposure And Methylation Efficiency In Relation To Oxidative Stress In Semiconductor Workers, Chih-Hong Pan, Ching-Yu Lin, Ching-Huang Lai, Hueiwang Anna Jeng

Community & Environmental Health Faculty Publications

This study examined associations between oxidative stress and arsenic (As) exposure and methylation efficiency in semiconductor workers. An As-exposed group (n = 427) and a control group (n = 91) were included. The As-exposure group (n = 427) included 149 maintenance staff members and 278 production staff members representing high As exposure and low As exposure, respectively. The control group included 91 administrative staff members with no or minimal As exposure. An occupational exposure assessment was conducted to assess personal As exposure by measuring As concentrations in urine, hair, and fingernails of the subjects. Urinary As(III), As(V), monomethylarsonic (MMA), and …

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