• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 53
  • 16
  • 16
  • 10
  • 8
  • 5
  • 5
  • 4
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 146
  • 23
  • 22
  • 14
  • 13
  • 13
  • 12
  • 12
  • 11
  • 10
  • 10
  • 9
  • 9
  • 9
  • 9
  • 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.
131

TU-Spektrum 3/2008, Magazin der Technischen Universität Chemnitz

Steinebach, Mario, Thehos, Katharina, Häckel-Riffler, Christine, Chlebusch, Michael, Friedrich, Sissy, Linne, Carina, Stromer, Anett, Rupp, Tanja, Leithold, Nicole 10 December 2008 (has links)
dreimal im Jahr erscheinende Zeitschrift über aktuelle Themen der TU Chemnitz
132

THERMAL MANAGEMENT TECHNOLOGIES OF LITHIUM-ION BATTERIES APPLIED FOR STATIONARY ENERGY STORAGE SYSTEMS : Investigation on the thermal behavior of Lithium-ion batteries

Ali, Haider Adel Ali, Abdeljawad, Ziad Namir January 2020 (has links)
Batteries are promising sources of green and sustainable energy that have been widely used in various applications. Lithium-ion batteries (LIBs) have an important role in the energy storage sector due to its high specific energy and energy density relative to other rechargeable batteries. The main challenges for keeping the LIBs to work under safe conditions, and at high performance are strongly related to the battery thermal management. In this study, a critical literature review is first carried out to present the technology development status of the battery thermal management system (BTMS) based on air and liquid cooling for the application of battery energy storage systems (BESS). It was found that more attention has paid to the BTMS for electrical vehicle (EV) applications than for stationary BESS. Even though the active forced air cooling is the most commonly used method for stationary BESS, limited technical information is available. Liquid cooling has widely been used in EV applications with different system configurations and cooling patterns; nevertheless, the application for BESS is hard to find in literature.To ensure and analyze the performance of air and liquid cooling system, a battery and thermal model developed to be used for modeling of BTMS. The models are based on the car company BMW EV battery pack, which using Nickel Manganese Cobalt Oxide (NMC) prismatic lithium-ion cell. Both air and liquid cooling have been studied to evaluate the thermal performance of LIBs under the two cooling systems.According to the result, the air and liquid cooling are capable of maintaining BESS under safe operation conditions, but with considering some limits. The air-cooling is more suitable for low surrounding temperature or at low charging/discharge rate (C-rate), while liquid cooling enables BESS to operate at higher C-rates and higher surrounding temperatures. However, the requirement on the maximum temperature difference within a cell will limits the application of liquid cooling in some discharge cases at high C-rate. Finally, this work suggests that specific attention should be paid to the pack design. The design of the BMW pack is compact, which makes the air-cooling performance less efficient because of the air circulation inside the pack is low and liquid cooling is more suitable for this type of compact battery pack.
133

Design and experimental investigation of an additive manufactured compact drive

Matthiesen, Gunnar, Merget, Daniel, Pietrzyk, Tobias, Ziegler, Stephan, Schleifenbaum, Johannes Henrich, Schmitz, Katharina 25 June 2020 (has links)
In recent years, additive manufacturing (AM) has become one of the most revolutionary and promising technologies in manufacturing. The process of making a product layer by layer is also often referred to as 3D printing. Once employed purely for prototyping, AM is now increasingly used for small series production, for example in aerospace applications. The paper starts with a motivation for AM in hydraulic applications and the development of an AM internal gear pump. For a better understanding of the manufacturing process, a brief introduction to AM highlighting the advantages and challenges is given. The AM internal gear pump is part of an electrohydraulic power pack, which is used to power an electrohydraulic actuator (EHA). The power pack contains all necessary peripherals to realise the hydraulic system of the EHA. The AM process allows for new design possibilities, but the process differs strongly compared to subtractive manufacturing processes and therefore is outlined here. The paper concludes by presenting measurement results of the AM internal gear pump.
134

Městské lázně / The Municipal Baths

Langová, Monika January 2010 (has links)
Designed construction of a spa with the wellness center programs (relaxation type), for 200-250 people (at one moment) at Brno city, near Voronez Hotel and Exhibition Centre. The five-floor spa building is designed as a puzzle in the shape originating from a dice. Cycles of water in its various forms and states of matter or properties fade into one another here. Each floor is designed to have its own theme (water world, the Asian world, aroma floor, salt floor, sunny and airy bath) and offers various types of premises and procedures: swimming, relaxing in the water, baths, showers, steam rooms, saunas, infrared saunas, wraps and massages etc. The spa program is accompanied by various types of refreshments: cafe, bar, tearoom, fruit bar. Rooftop pool and bar offers a unique view on the city. The spa and hotel Voronež parking is carried out within the ground floor.
135

Aging Propagation Modeling and State-of-Health Assessment in Advanced Battery Systems

Cordoba Arenas, Andrea Carolina January 2013 (has links)
No description available.
136

Meta model-based multi-objective optimization of laser welded dissimilar material joints for battery components

Andersson Lassila, Andreas January 2024 (has links)
During the assembly process of battery packs for electric vehicles, it is crucial to ensure that the cell-to-busbar joints can be produced with high quality, good reliability, and with minimal impact on the individual battery cells. This thesis project investigates the influence of different process parameters on the joint quality for laser welded dissimilar material cell-to-busbar joints. Nickel plated copper and steel plates, joined in an overlap configuration, are used as a simplified geometry, representing a cell-to-busbar joint. By the utilization of artificial neural network-based meta models, trained on numerical results from computational fluid dynamics simulations of the laser welding process, the joint quality is predicted and evaluated. The present thesis investigates how a set of optimized process parameters can be identified for the considered laser welded dissimilar material cell-to-busbar joints, in order to simultaneously maximize the interface width for the joints, and minimize the formation of undercuts and resulting in-process temperatures. NSGA-II is used to efficiently search for trade-off solutions, in an meta model-based multi-objective optimization approach, where the meta models are used to approximate the objectives, corresponding to the joint quality obtained from computational fluid dynamics simulations. With this, the time for one objective evaluation is reduced from approximately 9 hours, when the objectives are evaluated directly from computational fluid dynamics simulations, to only tenths of a second. With the proposed optimization approach, the Pareto-optimal front of trade-off solutions is identified, leading to the selection of three optimal solutions for validation. The validity of the proposed optimization approach, and the selected optimal solutions, are confirmed by means of both physical laser welding experiments and computational fluid dynamics simulations. It is shown that the selected optimal solutions, corresponding to three parameter setups, can be used to produce joints with large interface width and low in-process temperatures, without achieving a full penetration in the lower plate of the joint.
137

台灣電視記者一窩蜂新聞產製下的死結與活路-以重大社會事件報導為例 / Surviving Way and Dead End of TV Journalists in Pack Journalism:A Case Study of Breaking News

邱鈺婷, Chiu,Yu Ting Unknown Date (has links)
近幾年,台灣雖然有線頻道的開放,新聞媒體如雨後春筍冒出,但並無走向自由主義所奉行的「獨佔產生一致、競爭造成多元」的局面,反而造就新聞內容高度同質化、貧乏化與劣質化,基層新聞從業人員聲譽也每況愈下,飽受雙重壓力,外有各界針貶責難、內臨組織管理階層的不公平待遇。 許多研究將上述現象,歸咎於媒體結構(前端)的畸形,或從產製結果(後端)-內容面,剖析新聞場域的種種亂象。而本研究立旨於解構一窩蜂新聞產製現象中的來龍去脈、運作過程與利弊得失,故採不同於以往的分析取徑,以「電視新聞產製過程」(中端)中的行動者為主角,透過田野觀察、深度訪談取得研究資料,瞭解電視新聞從業人員與同業、電視新聞組織主管的互動關係,最後將田野資料進行紮根演繹,具體化研究目標與研究主題,瞭解電視新聞生產結構,並建立「一窩蜂新聞產製流程模式」。 本研究以「一窩蜂新聞學」(Pack Journalism)為根基,並以以「記者一窩蜂動作」為經,「與同業(同事)、決策者的互動關係」為緯,並援引Bourdieu新聞場域理論與Giddens的結構行動論,解析造成一窩蜂新聞產製與新聞同質化的內(記者個人心理)、外(新聞結構)在因素。 研究發現將一窩蜂新聞產製的成因分為五點,包括傳播者個人層次、常規層次、跨新聞組織層次、媒體外層次與社會文化層次。而本研究也發現新聞場域形成一迴路機制,藉由互相鏡射下,產生出速度政權與收視率的禁錮,在在都成為記者一窩蜂產製新聞的生存心態,導致新聞內容趨向高度同質化。不過,為了在場域的鬥爭中取得優勢地位,記者會藉由「秀異展示」,凸顯自己,轉化為具體目標,就是追求「獨家新聞」與建立「領導品牌」,在不知不覺中增強「象徵暴力」的施展能量,使記者本身陷入更深的束縛。 那新聞從業人員有抵抗的可能性嗎?本研究也發現新聞結構必須經過整頓,才有抵抗的空間,但在空間來臨之前,記者可以先行累積迂迴抵抗的資源,等待結構重整後才能一舉衝破牢網。 / In recent years, although Taiwan’s Government has allowed cable television stations to open and news media have expanded quickly, the development of television media deviates from the Liberalists’ ideal: monopoly leads to consistence, competition forms diversity. On the contrary, not only does Taiwan’s news content tend toward homogeneity and mediocrity, but also the status of journalists has gone from bad to worse. Journalists face two sets of pressures: there have been acute criticisms from Taiwanese society, and working conditions have deteriorated badly. Many research papers have dissected the above phenomenon in the news field, from the abnormality of media structure to the content of news production. This study aims to analyze the development, the operation, the merits and demerits of pack journalism, and therefore adopts a different approach from past analysis. In order to study pack journalism, this study adopts Bourdieu’s journalistic field theory and Giddens’ structure / activities theory to analyze news production processes. It focuses on journalists themselves and attempts to understand the interactive relationship of TV news workers, colleagues and managers though field study and in-depth interviews. Finally, I use grounded theory to analyze field information, concretizing the research subject and goals, with discussions of the model of news production in pack journalism. This study claims that there are five aspects of news production processes when studying pack journalism: individual level, media routines level, cross-news organization level, extra-media level and social-cultural level. The news field gives rise to a system marked by operational closure, which contributes to speed-driven news production and response to television ratings. These become the primary motives for journalists’ news generation, and result in homogeneity of news content. However, in order to advance in their field, journalists will try to distinguish themselves by pursuing scoops and branding themselves as leaders. Unconsciously, they reinforce the power of symbolic violence and get themselves into more complicated positions. Can news workers resist these scrapes? Can news workers resist these scrapes? Journalist need to accumulate resources to resist in the first place. With the efforts, the media structure is going to reorganized and then the journalists will have more space to stand firm the pressures of being homogeneity. After these changes take place, journalists may just be able to break through the shackles of pack journalism.
138

Capturing JUnit Behavior into Static Programs : Static Testing Framework

Siddiqui, Asher January 2010 (has links)
<p>In this research paper, it evaluates the benefits achievable from static testing framework by analyzing and transforming the <em>JUnit3.8 </em>source code and static execution of transformed code. Static structure enables us to analyze the code statically during creation and execution of test cases. The concept of research is by now well established in static analysis and testing development. The research approach is also increasingly affecting the static testing process and such research oriented work has proved particularly valuable for those of us who want to understand the reflective behavior of <em>JUnit3.8 Framework</em>.</p><p><em> JUnit3.8 Framework</em> uses <em>Java Reflection API</em> to invoke core functionality (test cases creation and execution) dynamically. However, <em>Java Reflection API</em> allows developers to access and modify structure and behavior of a program.  Reflection provides flexible solution for creating test cases and controlling the execution of test cases. Java reflection helps to encapsulate test cases in a single object representing the test suite. It also helps to associate each test method with a test object. Where reflection is a powerful tool to perform potential operations, on the other hand, it limits static analysis. Static analysis tools often cannot work effectively with reflection.</p><p>In order to avoid the reflection, <em>Static Testing Framework</em> provides a static platform to analyze the <em>JUnit3.8</em> source code and transform it into non-reflective version that emulates the dynamic behavior of <em>JUnit3.8</em>. The transformed source code has possible leverage to replace reflection with static code and does same things in an execution environment of <em>Static Testing Framework</em> that reflection does in <em>JUnit3.8</em>. More besides, the transformed code also enables execution environment of <em>Static Testing Framework</em> to run test methods statically. In order to measure the degree of efficiency, the implemented tool is evaluated. The evaluation of <em>Static Testing Framework</em> draws results for different Java projects and these statistical data is compared with <em>JUnit3.8</em> results to measure the effectiveness of <em>Static Testing Framework</em>. As a result of evaluation, <em>STF</em> can be used for static creation and execution of test cases up to <em>JUnit3.8</em> where test cases are not creating within a test class and where real definition of constructors is not required. These problems can be dealt as future work by introducing a middle layer to execute test fixtures for each test method and by generating test classes as per real definition of constructors.</p>
139

Dynamic modeling and feedback control with mode-shifting of a two-mode electrically variable transmission

Katariya, Ashish Santosh 31 August 2012 (has links)
This thesis develops dynamic models for the two-mode FWD EVT, develops a control system based on those models that is capable of meeting driver torque demands and performing synchronous mode shifts between different EVT modes while also accommodating preferred engine operating points. The two-input two-output transmission controller proposed herein incorporates motor-generator dynamics, is based on a general state-space integral control structure, and has feedback gains determined using linear quadratic regulator (LQR) optimization. Dynamic modeling of the vehicle is categorized as dynamic modeling of the mechanical and electrical subsystems where the mechanical subsystem consists of the planetary gear sets, the transmission and the engine whereas the electrical subsystem consists of the motor-generator units and the battery pack. A discussion of load torque is also considered as part of the mechanical subsystem. With the help of these derived dynamic models, a distinction is made between dynamic output torque and steady-state output torque. The overall control system consisting of multiple subsystems such as the human driver, power management unit (PMU), friction brakes, combustion engine, transmission control unit (TCU) and motor-generator units is designed. The logic for synchronous mode shifts between different EVT modes is also detailed as part of the control system design. Finally, the thesis presents results for responses in individual operating modes, EVT mode shifting and a full UDDS drive cycle simulation.
140

Mitteilungen des URZ 4/2004

Arnold,, Clauß,, Fischer,, Müller,, Richter,, Riedel,, Wegener,, Ziegler, 13 December 2004 (has links) (PDF)
Nutzerinformationen des Universitätsrechenzentrums

Page generated in 0.061 seconds