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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
281

Parametric Designs and Weight Optimization using Direct and Indirect Aero-structure Load Transfer Methods

Gandhi, Viraj D. 08 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Within the aerospace design, analysis and optimization community, there is an increasing demand to finalize the preliminary design phase of the wing as quickly as possible without losing much on accuracy. This includes rapid generation of designs, an early adaption of higher fidelity models and automation in structural analysis of the internal structure of the wing. To perform the structural analysis, the aerodynamic load can be transferred to the wing using many different methods. Generally, for preliminary analysis, indirect load transfer method is used and for detailed analysis, direct load transfer method is used. For the indirect load transfer method, load is discretized using shear-moment-torque (SMT) curve and applied to ribs of the wing. For the direct load transfer method, the load is distributed using one-way Fluid-Structure Interaction (FSI) and applied to the skin of the wing. In this research, structural analysis is performed using both methods and the nodal displacement is compared. Further, to optimize the internal structure, iterative changes are made in the number of structural members. To accommodate these changes in geometry as quickly as possible, the parametric design method is used through Engineering SketchPad (ESP). ESP can also provide attributions the geometric feature and generate multi-fidelity models consistently. ESP can generate the Nastran mesh file (.bdf) with the nodes and the elements grouped according to their geometric attributes. In this research, utilizing the attributions and consistency in multi-fidelity models an API is created between ESP and Nastran to automatize the multi-fidelity structural optimization. This API generates the design with appropriate parameters and mesh file using ESP. Through the attribution in the mesh file, the API works as a pre-processor to apply material properties, boundary condition, and optimization parameters. The API sends the mesh file to Nastran and reads the results file to iterate the number of the structural member in design. The result file is also used to transfer the nodal deformation from lower-order fidelity structural models onto the higher-order ones to have multi-fidelity optimization. Here, static structural optimization on the whole wing serves as lower fidelity model and buckling optimization on each stiffened panel serves as higher fidelity model. To further extend this idea, a parametric model of the whole aircraft is also created. / 2021-08-17
282

The Evaluation of Schools to College and Career (S2C) Readiness Program for Middle School Student

Gandhi, Sima D. 01 January 2020 (has links)
There is a lack of research on what it means to be college and career ready at the middle school level, and this creates confusion for students when they enter high school and must select courses that are aligned with their college and career goals. This study sought to understand how the Schools to College and Career (S2C) Readiness Program impacts middle school students at the charter school. In order to understand this impact, the study looked at how the S2C Readiness Program relates to students’ understanding and awareness of CCR at the school. Using a quantitative approach this study will sought to answer: What factors influence middle school students' awareness of college and career options after completing the S2C Readiness Program? To answer the guiding question middle school students completed two surveys. Archival data was also collected and analyzed. The results from the student survey responses showed an increase in interest in different careers as student performance level (measured from MAP score) increased. Furthermore, as students completed the S2C Readiness Program, their understanding of basic skills and content knowledge also increased. The results did show an increase in engagement and interest in their S2C elective courses. Also, students responded with an understanding of what it means to be college and career ready as they completed the S2C Readiness Program. There was also an increase in students seeking to understand what it means to be college and career ready as students get older. The research did not support a positive link between S2C elective class choice and college and career awareness. Many students responded that they did not explore college and career interests in their S2C class or on their own and did not engage in projects related to college and careers in their S2C elective class. This study sought to understand this impact, the study looked at how the S2C Readiness Program impacted students’ understanding and awareness of CCR at the charter school. Knowing that many students do not have the skills and tools necessary to be college and career ready this study hoped to provide insight for improving the S2C Readiness Program at the charter school. This research provided recommendations for improving the S2C Readiness Program at the charter school as well as college and career education opportunities in middle schools in general. This dissertation concluded with recommendations for future research to support such initiatives from elementary to the high school level.
283

Magnetic Resonance Elastography of the Kidneys

Gandhi, Deep B. 09 November 2018 (has links)
No description available.
284

Igneous petrology of Mount Yamaska, Quebec

Gandhi, Sunil Kumar Sunderlal. January 1966 (has links)
No description available.
285

A Real Time Indoor Navigation and Monitoring System for Firefighters and Visually Impaired

Gandhi, Siddhesh R 01 January 2011 (has links) (PDF)
ABSTRACT A REAL TIME INDOOR NAVIGATION AND MONITORING SYSTEM FOR FIREFIGHTERS AND VISUALLY IMPAIRED MAY 2011 SIDDHESH RAJAN GANDHI M.S. E.C.E, UNIVERSITY OF MASSACHUSETTS AMHERST Directed by: Professor Aura Ganz There has been a widespread growth of technology in almost every facet of day to day life. But there are still important application areas in which technology advancements have not been implemented in a cost effective and user friendly manner. Such applications which we will address in this proposal include: 1) indoor localization and navigation of firefighters during rescue operations and 2) indoor localization and navigation for the blind and visually impaired population. Firefighting is a dangerous job to perform as there can be several unexpected hazards while rescuing victims. Since the firefighters do not have any knowledge about the internal structure of the fire ridden building, they will not be able to find the location of the EXIT door, a fact that can prove to be fatal. We introduce an indoor location tracking and navigation system (FIREGUIDE) using RFID technology integrated with augmented reality. FIREGUIDE assists the firefighters to find the nearest exit location by providing the navigation instructions to the exits as well as an Augmented Reality view of the location and direction of the exits. The system also presents the Incident Commander the current firefighter’s location superimposed on a map of the building floor. We envision that the FIREGUIDE system will save a significant number of firefighters and victims’ lives. Blind or visually impaired people find it difficult to navigate independently in both outdoor and indoor environments. The outdoor navigation problem can be solved by using systems that have GPS support. But indoor navigation systems for the blind or visually impaired are still a challenge to conquer, given the requirements of low cost and user friendly operation. In order to enhance the perception of indoor and unfamiliar environments for the blind and visually-impaired, as well as to aid in their navigation through such environments, we propose a novel approach that provides context–aware navigation services. INSIGHT uses RFID (Radio Frequency Identification), and tagged spaces (audio landmarks), enabling a ubiquitous computing system with contextual awareness of its users while providing them persistent and context-aware information. We present INSIGHT system that supports a number of unique features such as: a) Low deployment and maintenance cost; b) Scalability, i.e. we can deploy the system in very large buildings; c) An on-demand system that does not overwhelm the user, as it offers small amounts of information on demand; and d) Portability and ease-of-use, i.e., the custom handheld device carried by the user is compact and instructions are received audibly.
286

Shock Compression of Body-Centered Cubic Metals from the Atomistic to Continuum Scale: Iron and Molybdenum

Gandhi, Vatsa Bhupeshkumar January 2023 (has links) (PDF)
<p>Fundamental understanding of material behavior under extreme conditions is crucial for designing high strength, light weight, and high temperature resistance materials, and for modeling planetary physics problems such as behavior of the core and impact phenomena. Under extreme conditions, materials not only exhibit a different mechanical, thermal, and failure response but can also undergo structural changes, such as phase transformations, which significantly alters their material properties. This motivates studying their dynamic response and developing constitutive models for applications such as hypersonics, high speed manufacturing, impact and blast of structures, aircraft and spacecraft shielding, meteorite impact, and collision of planets. Despite the importance, experimental investigations of shock induced phase transitions, inelastic material behavior, and elastic-plastic anisotropy under multi-axial stress states and at microscopic length scales of metals still remains largely unexplored. Thus, the focus of this thesis is on the shock compression behavior of body-centered cubic (BCC) metals, specifically iron and molybdenum, under compression-shear loading and at the atomistic-continuum spatial scales. In particular, the role of solid-solid phase transformation of body-centered cubic (BCC) iron on material strength and the orientation dependence of single crystal molybdenum on its elastic-plastic transition is investigated.</p> <p>Iron in its high pressure hexagonal close-packed (HCP) ϵ-phase is critical in geological and planetary applications such as inner cores of rocky planets and hypervelocity impacts of asteroids, and meteorites. Thus, understanding plasticity behavior of iron under these condensed matter states is important to develop more accurate models for such applications and to understand deformation mechanisms of inner planetary cores. Because the ϵ-phase is unstable, iron reverts to its ambient α-phase (BCC) upon release making it difficult to probe the strength behavior using conventional methods. Additionally, solid-solid phase transformations provide a unique opportunity to study material strength as they are crucial for expanding the design space for various load-bearing applications. In the first part of the thesis, the pressure dependent dynamic strength behavior of both the ambient BCC α-phase and high-pressure HCP ϵ-phase of iron at strain rates on the order of 1 X 10⁵ s⁻¹ and pressures up to 42 GPa is investigated. Pressure shear plate impact experiments are conducted using a sandwich configuration to decouple the effect of pressure and shear thereby allowing to probe shear strength once the sample reaches an equilibrated state of pressure but prior to release. The strength of the ϵ-phase is observed to be more than double the strength of α-phase possibly due to microstructural evolution during phase transformation. Additionally, the evolution of yield properties with pressure, temperature, and strain is presented for the first time, enabling more accurate modeling of extreme deformation phenomena associated with iron-rich celestial bodies such as planetary collisions.</p> <p>Molybdenum, its alloys, and other body-centered cubic (BCC) refractory metals are critical in geological and planetary applications such as structural properties of terrestrial planetary composition, formation of the earth-moon system, and hypervelocity impacts of rocky planets. Additionally, the high temperature specific strength, creep resistance, and ductility of BCC refractory metals make them ideal for aerospace and armor/anti-armor applications. Under high strain-rate inelastic loadings, the macroscopic response of these metals is often influenced by the atomistic mechanisms including dislocation motion and deformation twinning. Current material models rely on investigations that involve continuum measurements followed by postmortem microstructural analysis of recovered samples. However, these may not reflect the material behavior during the passage of the shock wave and, thus, requires real-time in-situ atomistic characterization to link the microstructure to macroscopic response. In the second part of the thesis, plate impact experiments coupled with both laser interferometry continuum measurements and <i>in-situ</i> dynamic Laue x-ray diffraction (XRD), at the Advanced Photon Source (APS), are conducted on single crystal molybdenum. Here, the role of crystal orientation, either [100] or [111], on deformation mechanisms during the elastic-plastic transition and the steady state response is explored at pressures ranging from 9-19 GPa. Complementary simulation methodology is developed to analyze the evolution of the Laue diffraction spots captured during impact. By extracting the lattice strain and stresses from XRD images, dislocation slip along [110]〈111〉 and [112]〈111〉 is found to be the probable deformation mechanism during compression with negligible anisotropy observed at the Hugoniot state. For the first time, real-time evidence of molybdenum undergoing deformation twinning along [112̅]〈111〉 during shock release beyond a critical pressure of 16 GPa irrespective of the loading orientation is presented.</p>
287

Forensic Analysis of GroupMe on Android and iOS Smartphones

Tanvi Milind Gandhi (11205891) 30 July 2021 (has links)
The growing popularity of instant messaging has led to the conception of several new applications over the span of the past decade. This has opened up an attack surface for cybercriminals to target susceptible app users. GroupMe is a free IM app widely used by students and so far, no comprehensive forensic analysis has been performed to aid forensic practitioners in recovering evidence from GroupMe on smartphones. This research performs a detailed analysis of the digital artifacts left by the app on Android and iOS devices. This was achieved by installing the app on two mobile phones (Samsung Galaxy S7 Edge and iPhone 6), and identifying each artifact created by performing a series of actions in the app ranging from sending texts, to sharing images and documents, along with their location. Using Cellebrite UFED and Magnet AXIOM, a significant number of artifacts were accurately recovered mainly from the “GroupMe.sqlite” and “GroupMe.sqlite-wal” databases. Out of the 335 artifacts populated on the iPhone, 317 were correctly recovered by both UFED and AXIOM, resulting in an accuracy of 94.62%. No GroupMe related artifacts could be recovered from the Android device. This was due to several physical imaging and rooting limitations imposed by the Samsung SM-935A model, which was used during the study.
288

Automatic Dependent Surveillance - Broadcast Enabled, Wake Vortex Mitigation Using Cockpit Display

Gandhi, Nikhil Tej January 2012 (has links)
No description available.
289

An Accuracy Improvement Method for Cricket Indoor Location System

Gandhi, Anall Vijaykumar 06 June 2013 (has links)
No description available.
290

IMPACT OF FERMENTED AND NON-FERMENTED PLANT-BASED FOODS SUPPLEMENTATION ON GUT MICROBIOTA AND METABOLITES IN C57BL/6J MICE

Gandhi, Priya Darshan 14 November 2023 (has links) (PDF)
Plant-based proteins have gained popularity because of their high nutritional value and more sustainable alternative to animal-based proteins. Soybean and chickpea are two widely consumed plant-based proteins, whereas tempeh is a popular plant-based fermented whole food product that is rich in protein. With the increase in the development of plant-based food products, there is little research into how plant proteins affect gut microbiota characteristics and metabolites. Therefore, there is a need to understand the underlying mechanisms surrounding the consumption of these foods. The purpose of this study was to investigate the health benefits of soybean, chickpea, and their tempeh counterparts’ consumption as whole foods on the gut microbiota and metabolites. Our results showed that soybean tempeh significantly increased the abundance of beneficial probiotic bacteria such as Roseburia and Ruminiclostridium 5 in the gut microbiota of mice. Additionally, soybean tempeh and soybean significantly increased Muribaculaeceae abundance, known to increase SCFA production in the colon. Lachnospiraceae NKA136 was significantly increased in soybean tempeh, soybean, and chickpea groups which may allow these foods to be used as a way of probiotic restoration. Our results showed that all dietary supplementation groups had significantly altered metabolic profiles compared to the control group. The soybean tempeh group had higher levels of peroxide (vitamin B6), myoinositol, and tetrahydrobiopterin while the chickpea tempeh group had higher levels of metabolites such as 3 hydroxyanthranilic acid. The soybean group had higher levels of metabolites such as 3-hydroxytryptophan (Oxitriptan) whereas the chickpea protein group had higher levels of metabolites such as 3-hydroxyanthranilic acid and oxitriptan. In conclusion, our study suggests that different plant-based foods can have distinct effects on gut microbiota and metabolic profiles in mice. These findings may have implications for human health and warrant further investigation into the effects of plant protein consumption on human metabolism.

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