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Articles 57811 - 57840 of 194897

Full-Text Articles in Engineering

Diagnóstico De La Explotación De Esmeraldas Mediante Minería Artesanal Y De Pequeña Escala En El Municipio De Chivor, Juan Yair Vaca Rodriguez, Daniel Hernando Cristobal Gonzalez Castellanos Jan 2018

Diagnóstico De La Explotación De Esmeraldas Mediante Minería Artesanal Y De Pequeña Escala En El Municipio De Chivor, Juan Yair Vaca Rodriguez, Daniel Hernando Cristobal Gonzalez Castellanos

Ingeniería Civil

Hoy en día la explotación minera de esmeraldas en el mundo se ha venido realizando y con mayor fuerza de manera artesanal en diferentes países que explotan gemas. Son pocos los países que tienen el privilegio de poseer depósitos de esmeraldas lo suficientemente significativos para su comercialización. Encabezando la lista se encuentra Colombia, que abastece el 55% del mercado mundial de esmeraldas, las cuales gozan de una gran popularidad por su buena calidad y gran tamaño. Le sigue Brasil con el 15%, Zambia 12%, Zimbawe 5%, Pakistán 5%. El 8% restante corresponde a otros países entre ellos Rusia, Tanzania, Austria …

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Estudio Y Análisis Multiobjetivo De Promedios Ponderados, Involucrando Criterios Técnicos, Ambientales Y Constructivos, Aplicados A Proyectos De Ingeniería Civil, En Este Caso Contrato Con El Instituto De Planificación Y Soluciones Energéticas Para Las Zonas No Interconectadas Ipse Y La Universidad De La Salle, Ana Milena Castillo Gómez Jan 2018

Estudio Y Análisis Multiobjetivo De Promedios Ponderados, Involucrando Criterios Técnicos, Ambientales Y Constructivos, Aplicados A Proyectos De Ingeniería Civil, En Este Caso Contrato Con El Instituto De Planificación Y Soluciones Energéticas Para Las Zonas No Interconectadas Ipse Y La Universidad De La Salle, Ana Milena Castillo Gómez

Ingeniería Civil

El presente trabajo está enfocado para aplicar metodología Multiobjetivo, involucrando criterios u objetivos de construcción, diseño y la parte ambiental en el proyecto que tenemos con el IPSE de interconexión Inírida (Colombia) – San Fernando de Atabapo (Venezuela), que se ejecuta en el departamento del Guainía Colombia y Amanavén en el departamento de Vichada. Se pretende comparar y clasificar de acuerdo a su impacto los diversos mecanismos con el fin de proponer medidas y revisar cual es la mejor opción para el proyecto. Tendremos varias etapas que harán parte de esta metodología.1. Definición de las alternativas.2. Selección de Objetivos o …

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Análisis De Resistencia Y Durabilidad Del Suelo Cemento Con Adición De Fibras Textiles De Jeans, Andrés Felipe Ruiz Gonzalez Jan 2018

Análisis De Resistencia Y Durabilidad Del Suelo Cemento Con Adición De Fibras Textiles De Jeans, Andrés Felipe Ruiz Gonzalez

Ingeniería Civil

No abstract provided.

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Guía Metodológica Para Instalaciones Hidráulicas De Redes Contra Incendio En Instituciones Educativas, Adriana González Castro, Jorge Andrés Sandoval Jimenez Jan 2018

Guía Metodológica Para Instalaciones Hidráulicas De Redes Contra Incendio En Instituciones Educativas, Adriana González Castro, Jorge Andrés Sandoval Jimenez

Ingeniería Civil

El presente documento se da a conocer una guía para la instalación hidráulica de una red contra incendio. En cuanto a los lineamientos para el diseño, construcción, mantenimiento y pruebas de sistemas contra incendio dando a conocer la normativa vigente de la NTC (Normas Técnicas Colombiana) y la NFPA (National Fire Protection Association) que es la norma adoptada a nivel mundial y especialmente en el continente americano al cual Colombia se encuentra asociado.Buscando proveer a la comunidad interesada un conocimiento necesario para adoptar criterios para la instalación de las redes contra incendio, donde predomina la facilidad de las consultas en …

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Presupuesto Técnico De Las Alternativas De Solución Planteadas Para El Sistema De Cimentación De Torres Eléctricas Ubicadas Sobre El Río Guaviare En El Corregimiento De Amanaven – Vichada, Yurley Medina Jaimes Jan 2018

Presupuesto Técnico De Las Alternativas De Solución Planteadas Para El Sistema De Cimentación De Torres Eléctricas Ubicadas Sobre El Río Guaviare En El Corregimiento De Amanaven – Vichada, Yurley Medina Jaimes

Ingeniería Civil

Dentro del proyecto de investigación “DIAGNOSTICO DEL ESTADO ACTUAL DE LA INFRAESTRUCTURA QUE FUE CONSTRUIDA CON OCASIÓN DE LA EJECUCIÓN DE LOS CONTRATOS INTERADMINISTRATIVOS 061-2011 Y 045-2012”, se requiere presentar el presupuesto técnico de las tres alternativas que den solución a las patologías presentadas. Para esto inicialmente se digitalizará la geología de la zona, posteriormente se procesarán los ensayos de laboratorio contratados con un laboratorio externo, de manera que se pueda obtener el perfil geotécnico representativo. Basados en el diseño de las alternativas de solución se desarrollará el presupuesto de cada una de las alternativas, lo cual incluye costos directos, …

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Análisis Del Comportamiento Mecánico De Adoquines De Concreto Con Adición De Fibra De Acero De Llantas Recicladas, Diego Alejandro Angarita Estupiñan, Oscar Mauricio Lizarazo Ariza Jan 2018

Análisis Del Comportamiento Mecánico De Adoquines De Concreto Con Adición De Fibra De Acero De Llantas Recicladas, Diego Alejandro Angarita Estupiñan, Oscar Mauricio Lizarazo Ariza

Ingeniería Civil

No abstract provided.

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Análisis De La Influencia De La Temperatura En El Comportamiento De La Dotación Neta Residencial A Partir De Datos De Consumo De Agua En Colombia, Julieth Paola Martínez Díaz, Juan Carlos Beltrán Pinzón Jan 2018

Análisis De La Influencia De La Temperatura En El Comportamiento De La Dotación Neta Residencial A Partir De Datos De Consumo De Agua En Colombia, Julieth Paola Martínez Díaz, Juan Carlos Beltrán Pinzón

Ingeniería Civil

No abstract provided.

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Protocolo Para La Identificación De Las Condiciones De Saneamiento Básico En Los Asentamientos Informales: Colina Ciudad Bolívar Y Fortuna Usme, Jaime Andrés Rojas Vaca, Jeffrey Andrés Sastoque Avendaño Jan 2018

Protocolo Para La Identificación De Las Condiciones De Saneamiento Básico En Los Asentamientos Informales: Colina Ciudad Bolívar Y Fortuna Usme, Jaime Andrés Rojas Vaca, Jeffrey Andrés Sastoque Avendaño

Ingeniería Civil

No abstract provided.

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Análisis De Probabilidad De Falla En Taludes En El Tramo Alto Medio De La Cuenca Del Río Únete, Municipio De Aguazul, Vereda La Vegana, Carlos David Torres Pachón, Fabián Camilo Marciales Leon Jan 2018

Análisis De Probabilidad De Falla En Taludes En El Tramo Alto Medio De La Cuenca Del Río Únete, Municipio De Aguazul, Vereda La Vegana, Carlos David Torres Pachón, Fabián Camilo Marciales Leon

Ingeniería Civil

En la ingeniería geotécnica se utiliza el factor de seguridad determinístico (F.S) para definir la estabilidad de un talud, pero como no es un valor exacto o que tome en cuenta variables diferentes al de los parámetros geotécnicos, en este trabajo de grado se hará la aplicación de métodos probabilísticos que estiman además del factor de seguridad una probabilidad de falla, el índice de confianza y que además de los factores geotécnicos también se tenga en cuenta factores sísmicos y de flujos de agua, que son los factores externos que más alteran la estabilidad de un talud, para esto se …

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Modelo De Elevación Litológico De La Cuenca Del Río Únete, Nydia Lorena Hernández Marín Jan 2018

Modelo De Elevación Litológico De La Cuenca Del Río Únete, Nydia Lorena Hernández Marín

Ingeniería Civil

La elaboración del modelo litológico de la Cuenca del Río Únete, consta de varias etapas de trabajo. Se inició con la recopilación de todos aquellos datos disponibles sobre el sector de estudio: informes regionales, mapas, cartografías, informes de pozos y apiques, etc., que fueron suministrados por entidades gubernamentales, entidades privadas y por el grupo investigativo del semillero GEOCAUSES. A partir de esto se conformó una base de datos que se organizó y valido, para posteriormente identificar un área específica de la cuenca que suministrara la cantidad más completa de parámetros de estudio y llegará dar inicio a la aplicación del …

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Efecto De Aditamento De Virutas Elastómeros Sbs En Las Propiedades Mecánicas Del Mortero, Manuel Julio Medina Torres Jan 2018

Efecto De Aditamento De Virutas Elastómeros Sbs En Las Propiedades Mecánicas Del Mortero, Manuel Julio Medina Torres

Ingeniería Civil

La presente investigación pretende evaluar el efecto de adición de viruta de elastómero SBS en los comportamientos mecánicos del mortero para la construcción. Donde la modificación del mortero se plantea como respuesta a las necesidades de utilizar los desperdicios del elastómero. Lo cual acontece cuando las personas depositan sus zapatos en la basura. En las compañías de calzado que según ACICAM (Asociación Colombiana de Industriales del calzado), la producción de 5.445 empresas dedicadas a la manufactura del calzado en Colombia representan el 2,17% en el PIB nacional y generan aproximadamente unas 20.000 toneladas de desechos de fábrica ; de los …

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Elaboración De Un Plan De Seguridad Del Agua Psa, Para El Aprovechamiento De Las Fuentes Hídricas Que Abastecen Los Municipios De Dibulla Y Riohacha, Javier Arturo Araoz Rojas Jan 2018

Elaboración De Un Plan De Seguridad Del Agua Psa, Para El Aprovechamiento De Las Fuentes Hídricas Que Abastecen Los Municipios De Dibulla Y Riohacha, Javier Arturo Araoz Rojas

Ingeniería Civil

Este proyecto fue realizado con el propósito de generar un avance en el estudio de la protección de los recursos hídricos en el Departamento de la Guajira. Como bien es conocido, el departamento de la Guajira es una de las regiones colombianas con más problemáticas sociales, entre ellas se pueden mencionar falta de ingresos, falta de recursos hídricos, territorios desérticos, escases de actividades productivas, altos índices de contaminación de los recursos hídricos, falta de escolaridad, deficiencia en la atención médica, entre otros. En el presente documento se recopila información relevante relacionada con la contaminación de los recursos hídricos, se abordan …

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Efficiency Improvement Of Fault-Tolerant Three-Level Power Converters, Ramin Katebi, Jiangbiao He, Waqar A. Khan, Nathan Weise Jan 2018

Efficiency Improvement Of Fault-Tolerant Three-Level Power Converters, Ramin Katebi, Jiangbiao He, Waqar A. Khan, Nathan Weise

Electrical and Computer Engineering Faculty Research and Publications

Fault-tolerant power converters play a critical role in the transportation electrification. However, fault-tolerant operation, high efficiency, and low cost usually result in design criteria that have conflicting constraints and goals. The majority of the fault-tolerant power converter topologies presented in the literature confirm these conflicts. In this paper, three types of fault-tolerant neutral-point clamped (NPC) converters are investigated. Various modulation strategies are explored to reduce the losses of the redundant phase leg. The simulation and experimental results show that the Switching Frequency Optimal Phase opposition Disposition modulation strategy is the most effective approach in minimizing the losses in the redundant …

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Analysis Of Aluminum-Air Battery By Physics-Based Mathematical Model, Chong Zhou Jan 2018

Analysis Of Aluminum-Air Battery By Physics-Based Mathematical Model, Chong Zhou

Graduate Research Theses & Dissertations

The demand of electrical energy system is increasing rapidly these days for diverse applications from portable electronics and electrical vehicles to grid-scale energy storage. Lithium-ion battery has been utilized for most of those applications, but due to high cost (about $600/ kWh) and lower energy density (0.37 kWh/kg), the advent of low cost and high performing battery system is required. In this study, we will revisit aluminum-air battery as a promising system which has excellent features such as high energy density of 2.8 kWh/kg, low cost, and safe in nature, but it was abandoned due to challenging issues. One of …

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Thickness Dependence Of Electrical Conductivity In A Thin Film Thermoelectric Composite, David Zagaceta, William Rogers, Andres Breucop, Brian Herrera Jan 2018

Thickness Dependence Of Electrical Conductivity In A Thin Film Thermoelectric Composite, David Zagaceta, William Rogers, Andres Breucop, Brian Herrera

Math 365 Class Projects

In this work we utilize the Van Der Pauw method for measuring and calculating the electrical conductivity of a composite material in relation to its thickness.

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Unlv Enrollment Analysis, Alexis Acosta, Juan Brena, Chaitanya Ingle, Ajanae' Williams Jan 2018

Unlv Enrollment Analysis, Alexis Acosta, Juan Brena, Chaitanya Ingle, Ajanae' Williams

Math 365 Class Projects

What will be the future enrollment for UNLV between 2021 to 2025? What will be the future enrollment for the College of Engineering between 2021 and 2025?

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Biomedical Informatics Applications For Precision Management Of Neurodegenerative Diseases, Justin B. Miller, Guogen Shan, Joseph Lombardo, Gustavo Jimenez-Maggoria Jan 2018

Biomedical Informatics Applications For Precision Management Of Neurodegenerative Diseases, Justin B. Miller, Guogen Shan, Joseph Lombardo, Gustavo Jimenez-Maggoria

Public Health Faculty Publications

Modern medicine is in the midst of a revolution driven by “big data,” rapidly advancing computing power, and broader integration of technology into healthcare. Highly detailed and individualized profiles of both health and disease states are now possible, including biomarkers, genomic profiles, cognitive and behavioral phenotypes, high-frequency assessments, and medical imaging. Although these data are incredibly complex, they can potentially be used to understand multi-determinant causal relationships, elucidate modifiable factors, and ultimately customize treatments based on individual parameters. Especially for neurodegenerative diseases, where an effective therapeutic agent has yet to be discovered, there remains a critical need for an interdisciplinary …

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Feasibility Of Using An Equilibrium Point Strategy To Control Reaching Movements Of Paralyzed Arms With Functional Electrical Stimulation, Matthew Huffman Jan 2018

Feasibility Of Using An Equilibrium Point Strategy To Control Reaching Movements Of Paralyzed Arms With Functional Electrical Stimulation, Matthew Huffman

ETD Archive

Functional electrical stimulation (FES) is a technology capable of improving the quality of life for those with the loss of limb movement related to spinal cord injuries. Individuals with high-level tetraplegia, in particular, have lost all movement capabilities below the neck. FES has shown promise in bypassing spinal cord damage by sending electrical impulses directly to a nerve or muscle to trigger a desired function. Despite advancements in FES, full-arm reaching motions have not been achieved, leaving patients unable to perform fundamental tasks such as eating and grooming. To overcome the inability in current FES models to achieve multi-joint coordination, …

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Improving The Security Of Mobile Devices Through Multi-Dimensional And Analog Authentication, Jonathan Gurary Jan 2018

Improving The Security Of Mobile Devices Through Multi-Dimensional And Analog Authentication, Jonathan Gurary

ETD Archive

Mobile devices are ubiquitous in today's society, and the usage of these devices for secure tasks like corporate email, banking, and stock trading grows by the day. The first, and often only, defense against attackers who get physical access to the device is the lock screen: the authentication task required to gain access to the device. To date mobile devices have languished under insecure authentication scheme offerings like PINs, Pattern Unlock, and biometrics-- or slow offerings like alphanumeric passwords. This work addresses the design and creation of five proof-of-concept authentication schemes that seek to increase the security of mobile authentication …

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Characterizing The Effects Of High-Intensity Exercise On Balance And Gait Under Dual-Task Conditions In Parkinson’S Disease, El Iva Baron Jan 2018

Characterizing The Effects Of High-Intensity Exercise On Balance And Gait Under Dual-Task Conditions In Parkinson’S Disease, El Iva Baron

ETD Archive

Parkinson’s disease (PD) is a neurodegenerative disorder, characterized by four cardinal motor symptoms including bradykinesia, tremor, rigidity, and postural instability, and non-motor symptoms including cognitive impairment. Daily activities, such as walking and maintaining balance, are impacted due to impairments in motor function, and are further exacerbated with the addition of cognitive loading, or dual-tasking (DT). High-intensity exercise has demonstrated centrally-mediated improvements of PD symptoms, with additional positive effects on overall health. The goal of this project was to identify changes in dynamic balance recovery and gait function under conditions with and without increased cognitive load after a high-intensity exercise intervention …

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Limits Of Small Scale Pressure Swing Adsorption, Aaron A. Moran Jan 2018

Limits Of Small Scale Pressure Swing Adsorption, Aaron A. Moran

ETD Archive

Portable or small scale pressure swing adsorption (PSA) systems have gained increasing popularity in both industry and literature due to the commercial success of personal oxygen concentrators (POCs). While these processes have much in common with larger PSA systems, significant differences exist that make understanding process limitations difficult. These include faster cycle times, smaller adsorbent particles, and a reduced column size. Macropore diffusion is traditionally assumed to control the mass transfer rate in columns packed with zeolite particles in an oxygen production process. While numerous studies have confirmed this assumption for the particle size used in industrial size PSA processes, …

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Neuromuscular Reflex Control For Prostheses And Exoskeletons, Sandra K. Hnat Jan 2018

Neuromuscular Reflex Control For Prostheses And Exoskeletons, Sandra K. Hnat

ETD Archive

Recent powered lower-limb prosthetic and orthotic (P/O) devices aim to restore legged mobility for persons with an amputation or spinal cord injury. Though various control strategies have been proposed for these devices, specifically finite-state impedance controllers, natural gait mechanics are not usually achieved. The goal of this project was to invent a biologically-inspired controller for powered P/O devices. We hypothesize that a more muscle-like actuation system, including spinal reflexes and vestibular feedback, can achieve able-bodied walking and also respond to outside perturbations. The outputs of the Virtual Muscle Reflex (VMR) controller are joint torque commands, sent to the electric motors …

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Human Activity Tracking And Recognition Using Kinect Sensor, Roanna Lun Jan 2018

Human Activity Tracking And Recognition Using Kinect Sensor, Roanna Lun

ETD Archive

The objective of this dissertation research is to use Kinect sensor, a motion sensing input device, to develop an integrated software system that can be used for tracking non-compliant activity postures of consented health-care workers for assisting the workers' compliance to best practices, allowing individualized gestures for privacy-aware user registration, movement recognition using rule-based algorithm, real-time feedback, and exercises data collection. The research work also includes developing a graphical user interface and data visualization program for illustrating statistical information for administrator, as well as utilizing cloud based database system used for data resource.

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Non-Intrusive Optical Measurement Of Electron Temperature In Near Field Plume Of Hall Thruster, Peter J. Urban Jan 2018

Non-Intrusive Optical Measurement Of Electron Temperature In Near Field Plume Of Hall Thruster, Peter J. Urban

ETD Archive

Currently there is a large interest in the use of more efficient means of propulsion in long term missions due to the costs and difficulties associated with placing and maintaining the needed fuel for conventional chemical systems in orbit. Mass reduction of upper stages will return large returns due to the great reduction in required lower stage fuel. Due to these factors, alternatives are undergoing active research, though this paper is concerned with the area of electrical propulsion. Electric propulsion is broadly defined as propulsion where the energization of the exhaust occurs via application of electromagnetic fields as opposed to …

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The Effect Of Cognitive Limb Embodiment On Vascular Physiological Response, Hala Elsir Mustafa Osman Jan 2018

The Effect Of Cognitive Limb Embodiment On Vascular Physiological Response, Hala Elsir Mustafa Osman

ETD Archive

The rubber hand illusion (RHI) is a visual-tactile perceptual illusion commonly used to study body ownership. In this paradigm, a rubber hand is positioned in front of a participant, and the person’s real hand is hidden from sight behind a barrier. When the real hand and the rubber hand are stroked synchronously, individuals perceive the rubber hand as if it were their own; it becomes “embodied.” This illusory experience of body ownership is associated with multimodal integration of touch and vision. From these visual-tactile-cognitive mechanisms, we establish that our hands belong to us when what we see matches what we …

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Drughelp.Care – A Web Application For The Discovery Of Drug Addiction Treatment Facilities, Sachin Hiriyanna Jan 2018

Drughelp.Care – A Web Application For The Discovery Of Drug Addiction Treatment Facilities, Sachin Hiriyanna

ETD Archive

One of the current and biggest problems in the system of emergency care for the drug overdose epidemic, is the failure of information delivery on nearby treatment facilities. Even though some initiatives on the internet tried to solve this issue, they either failed in delivering the information or in providing ease of usability. This thesis research aims to develop a web application which, 1. Delivers a highly accurate, easy-to-understand and targeted information in a timely manner for drug abusers and their well-wishers. 2. Provides an eco-system for the treatment facilities with an easy-to-use backend to constantly update their complex information …

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Color Removal From Combined Dye And Fruit Nectar Wastewater Using Adsorption And Microfiltration, Oluwatobiloba A. Akinwande Jan 2018

Color Removal From Combined Dye And Fruit Nectar Wastewater Using Adsorption And Microfiltration, Oluwatobiloba A. Akinwande

ETD Archive

Pollution of the waterways is a great challenge of the 21st century. Textile effluents contain compounds which have the capacity to cause more harm when ingested. There are many dye removal technologies like coagulation, photo oxidation which help to remove color from dye wastewater. The use of adsorption to remove color from dye wastewater has been used for many centuries. Activated carbon can efficiently remove color from dye wastewater but it is very expensive and so different researches have been conducted to get the adsorption capacity of different forms of adsorbents. These adsorbents can be gotten from agricultural waste, biomass, …

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Color Removal And Treatment Of Dye And Sugar Waste Water Using Low Cost Adsorbents, Saisantosh Vamshi Harsha Madiraju Jan 2018

Color Removal And Treatment Of Dye And Sugar Waste Water Using Low Cost Adsorbents, Saisantosh Vamshi Harsha Madiraju

ETD Archive

This study was undertaken to determine the treatment of wastewater from dye and sugar industry for removal of color. This specific treatment consists of adsorption using low cost adsorbents and micro filtration using whatman-41 micro filters. Considerations of this treatment process is to take the samples using batch adsorption and avoid coagulation with further dilution. Numerous runs were made with the ideal waste samples prepared in the laboratory. As a first step in the study different dyes were considered using different concentrations of sugar wastewater. Samples were treated with three different low-cost adsorbents. These treated samples using low cost adsorbents …

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A Transformative Process Control Solution, Simone Castanho Nobrega De Almedia Soares Jan 2018

A Transformative Process Control Solution, Simone Castanho Nobrega De Almedia Soares

ETD Archive

Knowing that a technology invented almost hundred years ago (PID controller) is still dominating industrial process control, a historical review was done to understand how the control field evolved. Model dependency and high level of mathematics appear as the main reasons that prevent other technologies from penetrating the engineering practice. A relatively novel methodology introduced by J. Han in 1998 called Active Disturbance Rejection Control (ADRC) came with characteristics that matches process control needs and restrictions on model dependency. This study will present a transformative solution for process control based on that. The control algorithm is designed and discretized for …

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High-Throughput Metabolism-Induced Toxicity Assays On A 384-Pillar Plate, Sooyeion Kang Jan 2018

High-Throughput Metabolism-Induced Toxicity Assays On A 384-Pillar Plate, Sooyeion Kang

ETD Archive

The U.S Environmental Protection Agency (EPA) launched the Transform Tox Testing Challenge in 2016 with the goal of developing practical methods that can be integrated into conventional high-throughput screening (HTS) assays to better predict the toxicity of parent compounds and their metabolites in vivo. In response to this need and to retrofit existing HTS assays for assessing metabolism-induced toxicity of compounds, we have developed a 384-pillar plate that is complementary to traditional 384-well plates and ideally suited for culturing human cells in three dimensions (3D) at a microscale. Briefly, human embryonic kidney (HEK) 293 cells in a mixture of alginate …

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