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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.
261

Design průmyslového vysavače / Design of Industrial Vacuum Cleaner

Rašínová, Jitka January 2017 (has links)
The thesis is focused on design of industrial vacuum cleaner for use in workshops. The thesis includes design and technical reaserch of current vacuum cleaners. The main part contains original design solution with regard to technical and ergonomics requirements.
262

Návrh a výroba vakuové formy pro sériové tváření plastů / A proposal and production of vacuum mold for serial production of plastic forming

Tišnovský, Jakub January 2019 (has links)
This diploma thesis deals with the proposal and production of a mold for series production of plastic parts by vacuum forming. The thesis is divided into 2 main chapters. The theoretical part includes analysis of chip machining technology. The experimental part focuses on solving the design of the mold in PowerShape software, a detailed analysis of making of the model for casting and about making of the mold themselves. In the last part the manual completion and verification of the mold is discussed. Thesis is terminated by technical-economic evaluation, in which is discussed about production costs.
263

Konstrukční návrh vakuového zařízení pro lití do silikonových forem / Design of vacuum chamber an equipment for vacuum casting process

Krajča, Martin January 2020 (has links)
The main aim of this thesis is to make a design of a vacuum casting chamber. The first part of this thesis is based on a research of the vacuum casting chamber which is available on the market, subsequently a thorough analysis of the casting process and key construction elements of the device is made. Most of the thesis focuses on making of a new construction design of the new device. At the end of the thesis economic evaluation and risk analysis is carried out.
264

Integrace podtlakového koncového efektoru do robotického pracoviště / Vacuum End-Effector Integrated in robotics station

Baják, Zdeněk January 2009 (has links)
The subject of this thesis is to complete the project vacuum end effectors for handling objects plate type. The work includes the completion of a 3D model, drawing, computer simulation uchopovacího positioning system, the draft control system for stepping motors and verification functions of effectors with the industrial robot ABB IRB 4400/60
265

Measurement of air flow at vacuum conditions using small Venturis

Alonso, Hector January 1980 (has links)
Small Venturis were used to measure air flow rates through cigarette-making machines to a vacuum header. A programmable calculator was used to develop charts for each Venturi. showing flow versus differential pressure at inlet vacuums from 8 in. (203 mm) to 20 in. (508 mm) of mercury. Use of the charts eliminates the need to calculate the flow each time a test is run. An error analysis indicated that large variations in temperature do not affect the result. The accuracy of the charts is not affected as long as the tests are run at room temperature. The Venturis, ranging in size from ½ in. (13 mm) to l ½ in. (38 mm) will continue to be used to measure and monitor vacuum requirements of the machines. / Master of Engineering
266

Modelling and Simulation of Fan Performance using CFD Group

Subramanya, Shreyasu January 2020 (has links)
Performance of vacuum cleaners are affected by factors such static pressure, airflow rate and efficiency. In this thesis work, attempt has been made to design a fan to meet the requirements of suction static pressure and air flow rate and in the process understand the fan design parameters that affect these performance parameters. Parametric study has been conducted for the same, by choosing six fan design parameters. Additionally, ways to increase the fan efficiency has been investigated during the parametric study. Computational Fluid Dynamics is used to visualize the flow inside the fan casing and further to simulate fan performance at an operational point. Steady state RANS and moving reference frames was used to model the turbulence in the fluid flow and rotation of the fan, respectively. Performance curve showing the relation between static suction pressure and mass flow rate is plotted for the base model is in proximity to the required performance. Parametric study was conducted on the six fan design parameters: Fan diameter, number of impeller blades, blade outlet angle, radius of the curve connecting inlet to outlet section of the fan, diffuser exit length and splitter blade length. The range for each parameter analysis was restricted so that static pressure values are around the required performance. Greater performance variation was found with design parameters: fan diameter, blade outlet angle, radius of the curve connecting inlet to outlet section of the fan and diffuser exit length. This variation at low mass flow rate can be majorly attributed to the randomness in the flow captured by entropy contours. At high mass flow rate, blockage in the flow visualized by pressure contours reasoned for the performance variation. Greater performance variation was not when design parameters such as number of blades and splitter blade length were varied. Larger variation of these parameters is required to see better variation.
267

Ionospheric Simulator (IonSim): Simulating Ionospheric conditions in a vacuum chamber

Dhar, Saurav 29 October 2013 (has links)
Understanding and improving ionospheric models is important for both military and civilian purposes. This understanding improves prediction of radio propagation used for communication and GPS navigation. Various space-borne instruments, such as retarding potential analyzers (RPAs) and ion traps are routinely flown in low earth orbit (LEO) to provide data for seeding/improve ionospheric models. This thesis describes and characterizes a new ion source that can be used to test and calibrate these space-borne instruments inside a laboratory vacuum chamber. Hot filaments are used to thermionically emit electrons inside the source. These electrons collisionally ionize neutral particles inside the source. Guided by ion-optics simulations, the ion and the electron trajectories inside the source are controlled to provide the required ion beams. A detailed description of the control electronics and the embedded controller for electron emission is discussed within. Using the custom made electronics, the source is able to provide an ion beam with current densities and mean energy comparable to the conditions in LEO. / Master of Science
268

Design And Development Of A Silicon Carbide Chemical Vapor Deposition Reactor

Smith, Matthew T 06 November 2003 (has links)
The goal of this thesis is to present the design and development of a chemical vapor deposition reactor for the growth of high quality homoepitaxy silicon carbide films for electronic device applications. The work was performed in the Nanomaterials and Nanomanufacturing Research Center at the University of South Florida from 8/2001-5/2003. Chemical vapor deposition (CVD) is the technique of choice for SiC epitaxial growth. Epitaxial layers are the building blocks for use in various semiconductor device applications. This thesis reports on a SiC epitaxy process where a carrier gas (hydrogen) is saturated with reactive precursors (silane and propane) which are then delivered to a semiconductor substrate resting on a RF induction heated SiC coated graphite susceptor. Growth proceeds via a series of heterogeneous chemical reactions with several steps, including precursor adsorption, surface diffusion and desorbtion of volatile by-products. The design and development of a reactor to make this process controlled and repeatable can be accomplished using theoretical and empirical tools. Fluid flow modeling, reactor sizing, low-pressure pumping and control are engineering concepts that were explored. Work on the design and development of an atmospheric pressure cold-wall CVD (APCVD) reactor will be presented. A detailed discussion of modifications to this reactor to permit hot-wall, low-pressure CVD (LPCVD) operation will then be presented. The consequences of this process variable change will be discussed as well as the necessary design parameters. Computational fluid dynamic (CFD) calculations, which predict the flow patterns of gases in the reaction tube, will be presented. Feasible CVD reactor design that results in laminar fluid flow control is a function of the prior mentioned techniques and will be presented.
269

Photo Processing and Microfabrication of Graphene Oxide / 酸化グラフェンの光プロセシングと微細加工

Tu, Yudi 26 March 2018 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第21106号 / 工博第4470号 / 新制||工||1695(附属図書館) / 京都大学大学院工学研究科材料工学専攻 / (主査)教授 杉村 博之, 教授 邑瀬 邦明, 教授 山田 啓文 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM
270

Mitigation of Undesirable Flavor in Kefir Intended for Adjuvant Treatment of <i>Clostridioides difficile</i> Infection

Kesler, Megan Kathleen January 2019 (has links)
No description available.

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