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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.
1

Constitutive modeling of fused deposition modeling acrylonitrile butadiene styrene (ABS)

Mamadapur, Monish Shivappa 15 May 2009 (has links)
Fused deposition modeling is a rapid prototyping process that is widely used to create prototypes. Acrylonitrile butadiene styrene is the most widely used material for fused deposition modeling. The parts are fabricated in a layer by layer fashion and the individual layers are composed of fibers that are deposited, thus making them similar to parts made of a composite material. This study tries to model the behavior of this composite-like material to aid designers in designing parts made of such a “rapid prototyped” material. The mechanical material constants that need to be determined in order to obtain the compliance/ stiffness matrix of the material have been identified and appropriate experiments have been conducted to determine them. Biaxial tensile tests have been conducted to obtain the Young’s moduli and Poisson’s ratios. Torsion tests have been conducted to obtain the Shear moduli. Three point bending tests and combined loading tests have been conducted. Most of the experimental results are in excellent agreement with the analytical/finite element simulation results. Some that are not give a greater insight into the material behavior and have been discussed.
2

none

Lin, Chia-Jung 14 June 2004 (has links)
none
3

Konsumentskyddet vid småhusentreprenader : Vad är fackmässighet? / Consumer Protection in Small House Contracts : What is Professionalism?

Heindoff, Alida, Johansson, Ida January 2015 (has links)
Under sin livstid genomför en konsument normalt få större investeringar. Köp av tjänst beträffande småhusentreprenad får anses utgöra en sådan investering. Att investera i uppbyggnad eller tillbyggnad av en- eller tvåfamiljshus är inte bara en stor ekonomisk investering för den enskilda konsumenten, utan också en investering för livet. Under de senare årtiondena har lagregleringen inom konsumenttjänsteområdet utvecklats och år 2005 infördes särskilda regler beträffande småhusentreprenader, i konsumenttjänstlagen (1985:716). Vanligt förekommande är även tillämpning av standardavtal som ska fungera som tillägg och komplement till konsumenttjänstlagen. ABS 09 är det standardavtal som tillämpas mellan näringsidkare och konsument beträffande avtal om småhusentreprenader. För att standardavtalet ska bli tillämpligt måste det dock åberopas av någon av parterna. Eftersom konsumenttjänstlagen är tvingande till konsumentens förmån får inte standardavtalsvillkoren strida mot lagen. Förekommer villkor i standardavtalet som anses strida mot lagen är dessa utan verkan. Standardavtal innehåller, till skillnad från konsumenttjänstlagen, rättigheter för näringsidkaren och det förekommer avtalsvillkor som i visst hänseende kan anses strida mot lagen. I analysen har vi kommit fram till att konsumentskyddet gällande småhusentreprenader har utvecklats och gett konsumenten ett starkare skydd. Det starka skyddet är till stor fördel för konsumenten, eftersom denne ofta är den svagare parten. I konsumenttjänstlagen stadgas att tjänsten ska utföras fackmässigt. Vad som är fackmässigt är ett begrepp som inte har en generell betydelse, utan innehållet i begreppet varierar från fall till fall. Det är inte bara konsumenttjänstlagen som reglerar fackmässighet utan även olika standardavtal. Efter att ha undersökt begreppet fackmässighet har vi kommit fram till att det inte är någon som egentligen vet vad begreppet egentligen betyder. I praktiken uppstår det sällan problem trots ovissheten kring begreppet i sig.
4

Parametry ovlivňující účinnost brzd osobních automobilů

Mikulášek, Václav January 2010 (has links)
No description available.
5

Senzory ve vozidlech a měření jejich signálů

Koláček, Stanislav January 2011 (has links)
No description available.
6

Elektronické systémy brzdové soustavy

Kočí, Václav January 2012 (has links)
No description available.
7

Protiblokovací systémy brzdové soustavy a systémy jízdní stability vozidel

Fischer, Michael January 2018 (has links)
Master’s thesis deals with anti-lock braking system and systems for riding stabilization of vehicles. Theoretical part of this paper describes active forces on a vehicle with emphasis on the braking process. The next part describes a design of a braking system with anti-lock braking system, and anti-slip regulation, and design of electronic stabilization program. Every subchapter dealing with system also contains a description of its function. Practical part of this thesis deals with measurement of braking with active and no active ABS done with Volkswagen Golf IV. This measurement was done on chassis dynamometer. Measured results describe the process of braking force and braking acceleration or deceleration. In the end of the thesis is comparison of results of braking with ABS for different pressure inside of tires.
8

Estudo do efeito da incorporação das argilas branca de Cubati e Cloisite Na® nas propriedades do termoplástico acrilonitrila butadieno estireno submetido à radiação ionizante / Study of effects of nanoclays light cream from cubati and cloisite Na® incorporation on properties of thermoplastic acrylonitrile butadiene styrene submitted by ionizing radiation

Sales, Jorge Nascimento de 18 November 2016 (has links)
O polímero Acrilonitrila Butadieno Estireno (ABS) é um dos polímeros mais versáteis disponíveis nos dias de hoje. Atualmente o Brasil não produz o ABS, o que limita a indústria brasileira de plásticos a utilizar as variações deste polímero importadas, ofertadas no mercado nacional por distribuidores locais. Este estudo avaliou os efeitos da adição das argilas Cloisite Na® e Branca de Cubati na matriz polimérica ABS e também os efeitos decorrentes do tratamento por radiação ionizante no ABS e nos compósitos ABS/Argila como formas de modificação de um ABS convencional. Visando avaliar a diferença entre uma argila organofílica e uma organofóbica, a argila Branca de Cubati foi organofilizada e a argila Cloisite Na® foi utilizada como recebida. Foram preparados, utilizando uma extrusora dupla rosca, concentrados a 30 % em massa da argila Branca de Cubati, previamente organofilizada e da Cloisite Na® em Estireno Acrilonitrila (SAN). Os concentrados foram adicionados ao ABS a 1, 3 e 5 % em massa das argilas e foram injetados corpos de prova. Parte dos corpos de prova foi submetida à irradiação por feixe de elétrons à uma dose de 600 kGy. Os compósitos irradiados e não irradiados foram caracterizados por meio de ensaios de resistência a tração, resistência a flexão, resistência ao impacto, temperatura de distorção térmica, ponto de amolecimento Vicat, análise de termogravimétrica (TG), difração de raios X e microscopia eletrônica de varredura com emissão de campo (MEVFEG) e a correlação entre os resultados foi discutida. Foram observadas melhorias nas propriedades mecânicas, exceto resistência ao impacto, nos materiais aditivados com as argilas, sendo os melhores resultados obtidos com a argila Branca de Cubati. O tratamento por radiação ionizante favoreceu o processo de reticulação do ABS. / The polymer Acrylonitrile Butadiene Styrene (ABS) is one of the most versatile polymers available today. Currently, Brazil does not produce ABS, which limits the Brazilian plastics industry to use the variations of this polymer imported, offered in the national market by local distributors. This study evaluated the effects of adding Cloisite Na® and Cubati Light Cream clays to the ABS polymer matrix and also the effects of ionizing radiation treatment on ABS and ABS/Clay composites as a way to modify a conventional ABS. Clays are naturally hydrophilic. Thus, in order to evaluate the difference between an organophilic clay and an organophobic, the Light Cream of Cubati was organophilized and the Cloisite Na® clay was used as received. A pre-organophilized Light Cream of Cubati and Cloisite Na® in Styrene Acrylonitrile (SAN) were prepared using a double screw extruder. The concentrates were added to the 1, 3 and 5% by weight ABS of the clays and specimens were injected. Part of the specimens was subjected to electron beam irradiation at a dose of 600 kGy. The irradiated and non-irradiated composites were characterized by tests of tensile strength, flexural strength, impact strength, thermal distortion temperature, Vicat softening point, thermogravimetric (TG) analysis, X-ray diffraction and electron microscopy of Field-emission scanning (SEM-FEG) and the correlation between the results was discussed. Improvements in mechanical properties were observed, except for impact resistance, in the materials added with the clays, and the best results were obtained with Cubati White clay. The treatment by ionizing radiation favored the ABS crosslinking process
9

Estudo do efeito da incorporação das argilas branca de Cubati e Cloisite Na® nas propriedades do termoplástico acrilonitrila butadieno estireno submetido à radiação ionizante / Study of effects of nanoclays light cream from cubati and cloisite Na® incorporation on properties of thermoplastic acrylonitrile butadiene styrene submitted by ionizing radiation

Jorge Nascimento de Sales 18 November 2016 (has links)
O polímero Acrilonitrila Butadieno Estireno (ABS) é um dos polímeros mais versáteis disponíveis nos dias de hoje. Atualmente o Brasil não produz o ABS, o que limita a indústria brasileira de plásticos a utilizar as variações deste polímero importadas, ofertadas no mercado nacional por distribuidores locais. Este estudo avaliou os efeitos da adição das argilas Cloisite Na® e Branca de Cubati na matriz polimérica ABS e também os efeitos decorrentes do tratamento por radiação ionizante no ABS e nos compósitos ABS/Argila como formas de modificação de um ABS convencional. Visando avaliar a diferença entre uma argila organofílica e uma organofóbica, a argila Branca de Cubati foi organofilizada e a argila Cloisite Na® foi utilizada como recebida. Foram preparados, utilizando uma extrusora dupla rosca, concentrados a 30 % em massa da argila Branca de Cubati, previamente organofilizada e da Cloisite Na® em Estireno Acrilonitrila (SAN). Os concentrados foram adicionados ao ABS a 1, 3 e 5 % em massa das argilas e foram injetados corpos de prova. Parte dos corpos de prova foi submetida à irradiação por feixe de elétrons à uma dose de 600 kGy. Os compósitos irradiados e não irradiados foram caracterizados por meio de ensaios de resistência a tração, resistência a flexão, resistência ao impacto, temperatura de distorção térmica, ponto de amolecimento Vicat, análise de termogravimétrica (TG), difração de raios X e microscopia eletrônica de varredura com emissão de campo (MEVFEG) e a correlação entre os resultados foi discutida. Foram observadas melhorias nas propriedades mecânicas, exceto resistência ao impacto, nos materiais aditivados com as argilas, sendo os melhores resultados obtidos com a argila Branca de Cubati. O tratamento por radiação ionizante favoreceu o processo de reticulação do ABS. / The polymer Acrylonitrile Butadiene Styrene (ABS) is one of the most versatile polymers available today. Currently, Brazil does not produce ABS, which limits the Brazilian plastics industry to use the variations of this polymer imported, offered in the national market by local distributors. This study evaluated the effects of adding Cloisite Na® and Cubati Light Cream clays to the ABS polymer matrix and also the effects of ionizing radiation treatment on ABS and ABS/Clay composites as a way to modify a conventional ABS. Clays are naturally hydrophilic. Thus, in order to evaluate the difference between an organophilic clay and an organophobic, the Light Cream of Cubati was organophilized and the Cloisite Na® clay was used as received. A pre-organophilized Light Cream of Cubati and Cloisite Na® in Styrene Acrylonitrile (SAN) were prepared using a double screw extruder. The concentrates were added to the 1, 3 and 5% by weight ABS of the clays and specimens were injected. Part of the specimens was subjected to electron beam irradiation at a dose of 600 kGy. The irradiated and non-irradiated composites were characterized by tests of tensile strength, flexural strength, impact strength, thermal distortion temperature, Vicat softening point, thermogravimetric (TG) analysis, X-ray diffraction and electron microscopy of Field-emission scanning (SEM-FEG) and the correlation between the results was discussed. Improvements in mechanical properties were observed, except for impact resistance, in the materials added with the clays, and the best results were obtained with Cubati White clay. The treatment by ionizing radiation favored the ABS crosslinking process
10

Model based wheel slip control via constrained optimal algorithm

Yoo, Dae Keun, not supplied January 2006 (has links)
In a near future, it is imminent that passenger vehicles will soon be introduced with a new revolutionary brake by wire system which replaces all the mechanical linkages and the conventional hydraulic brake systems with complete 'dry' electrical components. One of the many potential benefits of a brake by wire system is the increased brake dynamic performances due to a more accurate and continuous operation of the EMB actuators which leads to the increased amount of possibilities for control in antilock brake system. The main focus of this thesis is on the application of a model predictive control (MPC) method to devise an antilock brake control system for a brake by wire vehicle. Unlike the traditional ABS control algorithms which are based on a trial and error method, the MPC based ABS algorithm aims to utilizes the behaviour of the model to optimize the wheel slip dynamics subject to system constraints. The final implementation of the wheel slip controller emb races decentralized control architecture to independently control the brake torque at each four wheel. Performance of the wheel slip controller is validated through Software-in-the-Loop and Hardware-in-the-Loop simulation. In order to support the high demands of the computational power and the real time constraints of the Hardware-in-the-Loop simulation, a novel multi processor real-time simulation system is developed using the reflective memory network and the off-the-shelf hardware components.

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