1,884 research outputs found

    Electrical And Magnetic Separation Of Particles

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    Particle separation technologies have been utilized in many industrial fields, such as pigment and filler production, mineral processing, environmental protection, the food and beverage industry, and the chemical industry, as well as in biomedical application, such as cell biology, molecular genetics, biotechnological production, clinical diagnostics, and therapeutics. A lot of particle separation technologies using various mechanics in terms of the differences in the physical or physico-chemical properties of the particles have been developed. Among these categories, electrical and magnetic separations are of great interest in recent researches. The overall objective of this dissertation is to advance our current knowledge on these two particle separation technologies. Accordingly, it has two major parts:: 1) Charge Conditioning for Particle Separation, and: 2) Magnetic Filtering for Particle Separation. In the first part, a new DC-corona-based charge conditioner for critical control of electrical charges on particles and a UV aerosol charger for fundamental investigation particle photocharging process were developed. The chargers\u27 performances including charging efficiencies and charge distributions were evaluated upon different operational conditions such as aerosol flow rates, corona operations, and ion-driving voltages for the charge conditioner, particle material and irradiation intensity for the UV charger. The birth-and-death charging model with the Fuchs limiting sphere theory for calculating the ion-particle combination coefficient was applied to obtain the charging ion concentration inside the charge conditioner. The UV charging model with the photoemission rely on the Fowler-Nordheim law was applied to predict the charging performance of the UV charger. In the second part, a magnetic filter system has been constructed, and its performance has been investigated. To retrieve the magnetic property of characterized particles from the measured penetration data, a numerical model was further developed using the finite element package COMSOL Multiphysics 3.5. The numerical model was first validated by comparing the experimental penetration with the simulation results for the cases of 100, 150, and 250 nm r-Fe2O3 particles having the magnetic susceptibility characterized by Vibrating Sample Magnetometer: VSM). The magnetic susceptibilities of other sizes from 100 to 300 nm were then derived from this model according to the measured penetration data. To control or remove the lunar dust through a magnetic approach, eight samples: three JSC-1A series lunar dust simulants, two NU-LHT series lunar dust simulants, and three minerals) in the size range from 150 to 450 nm were characterized. Magnetic susceptibilities were obtained from the difference in particle penetration through magnetic mesh filters with and without an applied external magnetic field

    The Critical Role of Public Charging Infrastructure

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    Editors: Peter Fox-Penner, PhD, Z. Justin Ren, PhD, David O. JermainA decade after the launch of the contemporary global electric vehicle (EV) market, most cities face a major challenge preparing for rising EV demand. Some cities, and the leaders who shape them, are meeting and even leading demand for EV infrastructure. This book aggregates deep, groundbreaking research in the areas of urban EV deployment for city managers, private developers, urban planners, and utilities who want to understand and lead change

    Power systems research at MSFC

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    Power systems research reviews at Marshall Space Flight Cente

    Multi-kilowatt modularized spacecraft power processing system development

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    A review of existing information pertaining to spacecraft power processing systems and equipment was accomplished with a view towards applicability to the modularization of multi-kilowatt power processors. Power requirements for future spacecraft were determined from the NASA mission model-shuttle systems payload data study which provided the limits for modular power equipment capabilities. Three power processing systems were compared to evaluation criteria to select the system best suited for modularity. The shunt regulated direct energy transfer system was selected by this analysis for a conceptual design effort which produced equipment specifications, schematics, envelope drawings, and power module configurations

    Final report - Oslo Operational Pilot: Vulkan Car Parking, Oslo, Norway

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    This report provides a final report of the SEEV4-City Operational Pilot at the Vulkan parking garage in Oslo, Norway. It is part of a collection of reports published by the project covering a variation of specific and crosscutting analysis and evaluation perspectives and spans across 6 operational pilots. This report is dedicated to the analysis of the pilot itself

    Design of a man-wearable control station for a robotic rescue system

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    This report details the design, development, and testing of a man-wearable operator control station for the use of a low-cost robotic system in Urban Search and Rescue (USAR). The complete system, dubbed the "Scarab", is the 1st generation developed and built in the Robotics and Agents Research Laboratory (RARL) at the University of Cape Town (UCT), and was a joint effort between three MSc students. Robots have found a place in USAR as replaceable units which can be deployed into dangerous and confined voids in the place of humans. As such, they have been utilized in a large variety of disaster environments including ground, aerial, and underwater scenarios, and have been gathering research momentum since their first documented deployment in the rescue operations surrounding the 9/11 terrorist attacks. However one issue is their cost as they are not economical solutions, making them less viable for inclusion into a rescue mission as well as negatively affecting the operator‟s decisions in order to prioritise the safety of the unit. Another concern is their difficulty of transport, which becomes dependent on the size and portability of the robot. As such, the Scarab system was conceived to provide a deployable robotic platform which was lowcost, with a budget goal of US $ 500. To address the transportability concerns, it aimed to be portable and light-weight; being able to be thrown through a window by a single hand and withstanding a drop height of 3 m. It includes an internal sensor payload which incorporates an array of sensors and electronics, including temperature monitors and two cameras to provide both a normal and IR video feed. Two LED spotlights are used for navigation, and a microphone and buzzer is included for interaction with any discovered survivors. The operator station acts as the user interface between the operator and the robotic platform. It aimed to be as intuitive as possible, providing quick deployment and minimalizing the training time required for its operation. To further enhance the Scarab system‟s portability, it was designed to be a manwearable system, allowing the operator to carry the robotic platform on their back. It also acts as a charging station, supplying power to the robotic platform‟s on-board charging circuitry. The control station‟s mechanical chassis serves as the man-wearable component of the system, with the functionality being achieved by integration onto a tactical vest. This allows the operator to take the complete system on and off as a single unit without assistance, and uses two mounting brackets to dock the robotic platform. Key areas focussed upon during design were the weight and accessibility of the system, as well as providing a rugged housing for the internal electronics. All parts were manufactured in the UCT Mechanical Engineering workshop

    High Intensity Laser Power Beaming Architecture for Space and Terrestrial Missions

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    High Intensity Laser Power Beaming (HILPB) has been developed as a technique to achieve Wireless Power Transmission (WPT) for both space and terrestrial applications. In this paper, the system architecture and hardware results for a terrestrial application of HILPB are presented. These results demonstrate continuous conversion of high intensity optical energy at near-IR wavelengths directly to electrical energy at output power levels as high as 6.24 W from the single cell 0.8 cm2 aperture receiver. These results are scalable, and may be realized by implementing receiver arraying and utilizing higher power source lasers. This type of system would enable long range optical refueling of electric platforms, such as MUAV s, airships, robotic exploration missions and provide power to spacecraft platforms which may utilize it to drive electric means of propulsion

    Physical and chemical characterization of single atmospheric aerosols: Laboratory studies of interactions of acidic trace gases with sea -salt aerosols, and, Development efforts for an aerosol charging system using a corona discharge

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    There has long been an interest for in situ analysis of single atmospheric aerosols. To this end, the Flytrap instrument was developed under a NASA Phase I and Phase II Small Business Innovative Research Grant. The centerpiece of the instrument was a spherical void electrodynamic levitator that was used to suspend and optically characterize the physical and chemical properties of individual aerosols. Physical measurements of the aerosols were conducted with the aid of a Mie scattering system while chemical characterization was conducted with a Raman spectroscopy microprobe. A large effort focused on development of a system for charging and trapping atmospheric aerosols using a corona discharge. Testing of this charging device indicated that only aerosols larger than twenty microns in diameter could be successfully charged and trapped. Once assembled, calibrated and tested, the Flytrap instrument was used to study the interaction between acidic trace gases and artificial sea-salt aerosols in a laboratory environment. The chamber housing the spherical void electrodynamic levitator was designed to simulate conditions found in a polluted marine boundary layer. The reactive uptake coefficient between nitric acid and sea-salt aerosols under a variety of relative humidity and alkalinity conditions was measured. The uptake coefficient varied strongly with changes in relative humidity, time and alkalinity. In addition, oxidation of sulfur dioxide to sulfate in sea-salt aerosols was studied under a variety of alkalinity conditions. It was found that these reaction rates also varied strongly with oxidant type, changes in relative humidity, time and alkalinity

    Optimization and Control of Lumped Transmitting Coil-Based In-Motion Wireless Power Transfer Systems

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    Wireless inductive power transfer systems are the only viable option for transferring energy to a moving vehicle. In recent years, there has been a great deal of interest in in-motion vehicle charging. The dominant technology thus far for in motion charging is elongated tracks, creating a constant eld for the moving vehicle. This technology suers from high volt ampere ratings and lower efficiency of 70%. On the other hand, stationary charging systems can demonstrate efficiency up to 95%. This thesis proposes lumped coils, similar to stationary charging coils for in-motion electric vehicle charging application. This novel primary coil architecture introduces new challenges in optimization and control. Traditional design of wireless inductive power transfer systems require designer experience, use of time consuming 3D FEM algorithms and lacks the comprehensive nature required for these systems. This thesis proposes two new optimization algorithms for the design problem which are comprehensive, based on only analytical formulations and do not need designer experience. There are challenges in the control of power transfer as well. Higher efficiency comparable to stationary systems can only be realized with proper synchronization of primary voltage with the vehicle position. Vehicle position detection and communication introduce significant cost and convenience issues. This thesis proposes a novel control algorithm which eliminates the need for vehicle position sensing and yet transfers the required percentage of energy. Both the optimization and control algorithms are verified with hardware setup
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