• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 94
  • 43
  • 36
  • 10
  • 9
  • 8
  • 3
  • 3
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 257
  • 43
  • 31
  • 30
  • 28
  • 23
  • 23
  • 22
  • 21
  • 21
  • 20
  • 19
  • 19
  • 18
  • 18
  • 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.
71

Seat Belt Fit a Mechanism of Injury During a Motor Vehicle Crash

Viljoen, Jacoba Hendrika 01 January 2018 (has links)
Seat belts save lives; however, unintentional injuries are still the leading cause of death for those between 1 and 44 years in the United States. Seat belts also cause injuries during motor vehicle crashes (MVCs) and obesity changes how seat belts fit. The purpose of this retrospective causal inference quantitative study was to reduce the knowledge gap in scholarly research on seat belt fit in relation to blunt cerebrovascular injuries (BCVI) during MVCs and seat belt compliance. The theoretical framework used was based on H.W. Heinrich's domino theory. The research questions focused on the following dependent variables: BCVI, compliance, and seat belt fit; and independent variables: the size of the individual and seat belt fit. Secondary and primary data were used and analyzed using Spearman's Rank-Order Correlation. The results yielded no relationship between seat belt fit and BCVI in the secondary data (n = 97). In the primary data (n = 138), there was significance found between seatbelt fit and a) seat belt use, and b) BMI. The study contributed to positive social change by enhancing the awareness of the knowledge deficit regarding seat belt fit, and BCVIs sustained during MVCs, and that comfort was influenced by seat belt fit and had a role in compliance. Seat belts were not used by 5.3% and 9.5% or used incorrectly by 3.2% and 2.9% of the people in the primary data and secondary data sets. This knowledge may contribute to a) future seat belt testing to ensure it is done in such a manner that seat belts fit everyone; b) new seat belt laws to ensure that they are consistent across all states, and c) medical care focusing on seat belt fit as a mechanism of injury (blunt) to ensure screenings are done with the appropriate diagnostic tools.
72

How to Increase Usage of Child Restraint Systems in China : A design research

Nyström, Emma, Ringedal, Andreas January 2014 (has links)
Every year 9000 children are estimated to die in traffic accidents in China. Fast motorization of the country in combination with low usage of child restraint system’s (CRS’s), are the two contributing factors to this alarming number. The vision of this thesis is to increase the usage of CRS’s in China, by understanding why the users are using the CRS and why the non-users are not using. The behavioural methodology Switch was used to investigate what positive behaviours could be copied and implemented in a larger scale to increase the usage. Interviews were performed with 30 users and 30 non-users in tier 1, tier 2, and tier 3 cities on the east coast of China. The main findings from the interviews showed that the reasons for not using was that the parents found the CRS complicated to install and to use, that it took too much space, that they did not know the benefits with a CRS and found it unnecessary and that they could not convince their children to sit in the CRS. Surprisingly most non-users already owned a CRS, but stopped using it. The users were using because they had experienced the CRS from abroad or got knowledge from other sources such as media or friends. Some parents were using because of a practicality issues such as the trouble to hold a heavy 3-year old child during a long trip. The behaviours chosen to represent the users for further work were learning from others, selection support, how to install, how to persist, and how to pay the knowledge of the CRS forward. The behaviour of the users was copied and implemented in a strategy consisting of the five parts above. The strategy is an interactive webpage with a close linkage to social networks to encourage sharing, and with a supporting poster- and bumper sticker campaign for spreading. The final product of the thesis work is a campaign including a fully working prototype of the webpage, which will be handed over to Volvo Cars for verification internally to make sure that the concept supports the different parts in a suitable and correct way before a public implementation. Material for poster and bumper stickers is also a part of the final delivery.
73

Pozice značky Seat v rámci portfolia skupiny Volkswagen na evropském trhu osobních automobilů / Pozition of the SEAT brand in the VW Group portfolio in European market of personal cars

Kubátová, Michaela January 2013 (has links)
The main objective of the thesis is an analysis of the position of the SEAT brand in the VW Group portfolio. The main focus of the work stays in the European market of personal cars. The work consists of two parts. The first part explains the theoretical tools needed for branding and brand management. Specifically, it is devoted to the brand and its attributes as well as positioning and segmentation, considering also the specifics of the automotive industry in the European market. The second part is analyzing the SEAT brand from two main points of view. The first considers only the VW portfolio. The second one analyses SEAT given its European main competitors. Brand positioning, the automotive market development trends and European customer preferences represent the basis for the comparison in both fields. The findings of the work explain if there is a potential for the SEAT brand to stay in the VW portfolio.
74

The mechanics of valve cooling in internal-combustion engines : investigation into the effect of VSI on the heat flow from valves towards the cooling jacket

Abdel-Fattah, Yahia January 2009 (has links)
Controlling the temperature of the exhaust valves is paramount for proper functioning of engines and for the long lifespan of valve train components. The majority of the heat outflow from the valve takes place along the valve-seat-cylinder head-coolant thermal path which is significantly influenced by the thermal contact resistance (TCR) present at the valve/seat and seat/head interfaces. A test rig facility and experimental procedure were successfully developed to assess the effect of the valve/seat and seat/head interfaces on heat outflow from the valve, in particular the effects of the valve/seat interface geometry, seat insert assembly method, i.e. press or shrink fit, and seat insert metallic coating on the operating temperature of the valve. The results of tests have shown that the degree of the valve-seat geometric conformity is more significant than the thermal conductivity of the insert: for low conforming assemblies, the mean valve head temperature recorded during tests on copper-infiltrated insert seats was higher than that recorded during tests on noninfiltrated seats of higher conformance. The effect of the insert-cylinder head assembly method, i.e. shrink-fitted versus press-fitted inserts, has proved negligible: results have shown insignificant valve head temperature variations, for both tin-coated and uncoated inserts. On the other hand, coating the seat inserts with a layer of tin (20-22μm) reduced the mean valve head temperature by approximately 15°C as measured during tests on uncoated seats. The analysis of the valve/seat and seat/head interfaces has indicated that the surface asperities of the softer metal in contact would undergo plastic deformation. Suitable thermal contact conductance (TCC) models, available in the public domain, were used to evaluate the conductance for the valve/seat and seat/cylinder head interfaces. Finally, a FE thermal model of the test rig has been developed with a view to assess the quality of the calculated TCC values for the valve/seat and seat/head interfaces. The results of the thermal analysis have shown that predicted temperatures at chosen control points agree with those measured during tests on thermometric seats with an acceptable level of accuracy, proving the effectiveness of the used TCC models.
75

TRANSMISSIBILIDADE DA VIBRAÇÃO E DISTRIBUIÇÃO DA PRESSÃO NA INTERFACE ASSENTO-OPERADOR DE TRATORES AGRÍCOLAS EM CONDIÇÕES DINÂMICAS / TRANSMISSIBILITY OF VIBRATION AND PRESSURE DISTRIBUTION IN THE SEAT-OPERATOR INTERFACE OF AGRICULTURAL TRACTORS IN DYNAMIC CONDITIONS

Roth, Claudio Weissheimer 26 November 2010 (has links)
Substantive changes introduced in the agricultural work, driven by further increases in productivity in the agricultural machinery are the basis of this study. The tractor is a machine used in most activities of tillage, by concentrating most of the physical and mechanical actions to perform these activities. The tractor seat is one of the most important factors to be considered in the design of the workplace, it is the area where the operator remains for hours. The aim of this study was to analyze the transmissibility of vibration and pressure distribution in the seat-operator interface in two types of seats in agricultural tractors, in two settings for suspension in three forward speeds and three different types of micro-reliefs. Were performed simultaneous field experiments with measurements of amplitude of vibrations and pressure distribution on a path of 40 meters in three distinct areas, consolidated, ploughed and asphalt, in three average speeds, 4.66, 5.57 and 6.58 km/h. The data of operator exposure to whole body vibration were obtained through the RT Pro Photon 6.30 system, which performs simultaneous readings in the triaxial axes x, y and z and to measure the pressure distribution was used a blanket sensorized interface module of the X-sensor system. Later, the parameters which allowed the evaluation of the transmissibility of vibration were calculated, as well as the distribution of pressures on the trunk of the operator in the seat. Was performed an Analysis of Variance (ANOVA) and Duncan Test. The level of significance was the 95% reliability. It was concluded that in consolidated and ploughed areas the effective accelerations exceeded the upper limit of the little discomfort zone of standard 2631-1:1997 and that the actual magnitude of the transmissibility of vibration increased on frequencies of 2.5 and 12.5 Hz. The maximum limit of comfort and daily work of eight hours have been overcome by the magnitude of the effective accelerations in all the tests and by the accelerations in more than one direction, in the frequency ranges of 2.5 and 5 Hz on consolidated and mined areas. The values of the average pressures of seat B1 were around 25% lower than the seat B2 medium pressure on consolidated and ploughed areas and their distribution was similar between the two benches, regardless of the setting of the suspension regulation. The dynamic capability to mitigate sudden changes of pressure of seat B1 was higher in regulation R1 and on seat B2, in the regulation R2, considering that on the wrought soil regulation R2 of seat B2 showed an ability to reduce the sudden pressure 50% lower than the regulation R1. Areas of effective contact in the seat-operator interface were 20% higher on the seat B1 than seat B2. / As alterações substanciais introduzidas no trabalho agrícola, impulsionadas por aumentos adicionais de produtividade nas máquinas agrícolas são a base deste estudo. O trator é a máquina mais usada nas atividades agrícolas, por concentrar a maioria das ações físicas e mecânicas para executar essas atividades. O assento do trator é um dos mais importantes fatores a ser considerado no projeto do posto de trabalho, pois é o local onde o operador permanece por mais horas. O objetivo deste estudo foi analisar a transmissibilidade das vibrações e a distribuição da pressão na interface assento-operador em dois tipos de bancos de tratores agrícolas, em duas regulagens de suspensão, em três velocidades de deslocamento e três diferentes tipos de micro-relevos. Foram realizados experimentos simultâneos a campo com medição da amplitude das vibrações e da distribuição da pressão na superfície de contato entre o homem e o banco em trajetos de 40 metros em três distintas áreas, consolidada, lavrada e asfáltica, em três velocidades médias, 4,66, 5,57 e 6,58 km/h. Os dados da exposição do operador à vibração de corpo inteiro foram obtidos através do sistema RT Pro Photon 6,30, que executa simultaneamente leituras nos eixos triaxiais x, y e z e para medir a distribuição da pressão foi utilizada uma manta sensorizada do sistema X-sensor. Posteriormente, foram calculados os parâmetros que permitiram a avaliação da transmissibilidade das vibrações, assim como da distribuição das pressões do tronco dos operadores no assento do banco. Foi realizada a Análise de Variância (ANOVA) e Teste de Duncan. O nível de significância aceito foi de 95% de confiabilidade. Concluiu-se que nas áreas consolidada e lavrada as acelerações eficazes ultrapassaram o limite superior da zona de pouco desconforto da norma 2631-1:1997 e que a amplitude efetiva da transmissibilidade das vibrações aumentou nas frequências de 2,5 e 12,5 Hz. Os limites máximos conforto e de trabalho diário de 8 horas foram ultrapassados pelas magnitudes das acelerações eficazes na totalidade dos ensaios e pelas acelerações em mais de uma direção, nas faixas de frequência de 2,5 e 5 Hz nas áreas consolidada e lavrada. Os valores das pressões médias do banco B1 foram em torno de 25% menores que as pressões médias do banco B2 nas áreas consolidada e lavrada e sua distribuição ocorreu de maneira semelhante entre os dois bancos, independente do tipo de regulagem da suspensão. A capacidade dinâmica de atenuar as mudanças repentinas de pressão do banco B1 foi superior na regulagem R1 e no banco B2, na regulagem R2, sendo que no solo lavrado a regulagem R2 do banco B2 apresentou uma capacidade 50% menor do que a regulagem R1. As áreas de efetivo contato na interface banco-operador foram 20% maiores no banco B1 que no banco B2.
76

Mezinárodní právo soukromé ve srovnávacím pohledu (srovnání vybraného úseku v českém právu a právu zvoleného státu): Mezinárodní právo společností v České republice a ve Spolkové republice Německo / Private international law from a comparative perspective (comparison of a particular segment in Czech law and the law of a selected country): International company law in the Czech Republic and in the Federal Republic of Germany

Lindauerová, Natálie January 2016 (has links)
Summary: Private international law from a comparative perspective (comparison of a particular segment in Czech law and the law of a selected country): International company law in the Czech Republic and in the Federal Republic of Germany The purpose of this thesis to familiarize reader with the regulation of companies in private international law in the Czech Republic and in the Federal Republic of Germany. This thesis primarily compares the approaches of these two states to the methods of determining the personal status of the company and to the regulation of companies in general. Significant part of this thesis is therefore being focused on to the incorporation theory and real seat theory. Due to the membership of both of the states in the European Union, this thesis also deals with the European regulation of companies and analyzes the case law relating to the personal status and relocation of companies within European Union. This thesis is divided in six chapters. The first chapter explains the concept of international private law and international company law. The second chapter discusses the status of the company and basic theoretical approaches to its determination. This chapter is mainly dedicated to the incorporation theory and real seat theory. The third chapter is devoted to the Czech regulation...
77

Společnosti v mezinárodním právu soukromém / Companies in private international law

Botová, Hana January 2015 (has links)
Companies in private international law Abstract The purpose of my thesis is to analyze the regulation of companies in private international law with the focus on the possibilities of cross-border movement of companies. In today's globalized society, the mobility of companies affects both economy of the state and lives of the employees, creditors and other parties. It is therefore subject to regulation. State's conflict of laws rules are based on two main methods to determine the status of the company, i.e. the incorporation doctrine and the real seat doctrine. These two doctrines are clashing in many aspects. The thesis is composed of an introduction, followed by five chapters, and a summary. Chapter One is introductory and defines basic terminology used in the thesis: the terms company and private international law. The second chapter explains the concept of status of a company and analyses the incorporation theory, the theory of real seat and the theory of super-addition. It also deals with the cross-border transfer of seat. Chapter Three examines Czech legislation regarding the personal status of a company. It explains the historical background and recent Czech concept of the incorporation theory, addresses the issue of seat in Czech law and investigates the regulation of cross-border transfer of seat....
78

Svoboda usazování obchodních společností v evropském právu / Freedom of Establishment of Companies in European Law

Horák, Milan January 2012 (has links)
States have traditionally dealt with foreign companies on their territory within their private international law. The arrival of European law and enactment of freedom of establishment though considerably constrained capabilities of member states, whereas companies gained the right of establishment. The aim of this thesis is characterization and specification of the relationship between the freedom of establishment, member states and companies incorporated under laws of member states. The main focus of this thesis is analysis of ten most important cases by the Court of Justice of the European Union concerning the freedom of establishment of companies, which significantly transformed mentioned relationship. Subsequently the thesis summarizes the conclusions of analyzed cases by subject of evolution of primary and secondary freedom of establishment, standing of pseudoforeign companies, conformity with incorporation theory and real seat theory and lastly ways of statutory and/or real seat transfer. The main contribution of the thesis is the very detailed case law analysis, including the newest case Vale from July 12th 2012, and also the case law classification by object.
79

The mechanics of valve cooling in internal-combustion engines. Investigation into the effect of VSI on the heat flow from valves towards the cooling jacket.

Abdel-Fattah, Yahia January 2009 (has links)
Controlling the temperature of the exhaust valves is paramount for proper functioning of engines and for the long lifespan of valve train components. The majority of the heat outflow from the valve takes place along the valve-seat-cylinder head-coolant thermal path which is significantly influenced by the thermal contact resistance (TCR) present at the valve/seat and seat/head interfaces. A test rig facility and experimental procedure were successfully developed to assess the effect of the valve/seat and seat/head interfaces on heat outflow from the valve, in particular the effects of the valve/seat interface geometry, seat insert assembly method, i.e. press or shrink fit, and seat insert metallic coating on the operating temperature of the valve. The results of tests have shown that the degree of the valve-seat geometric conformity is more significant than the thermal conductivity of the insert: for low conforming assemblies, the mean valve head temperature recorded during tests on copper-infiltrated insert seats was higher than that recorded during tests on noninfiltrated seats of higher conformance. The effect of the insert-cylinder head assembly method, i.e. shrink-fitted versus press-fitted inserts, has proved negligible: results have shown insignificant valve head temperature variations, for both tin-coated and uncoated inserts. On the other hand, coating the seat inserts with a layer of tin (20-22¿m) reduced the mean valve head temperature by approximately 15°C as measured during tests on uncoated seats. The analysis of the valve/seat and seat/head interfaces has indicated that the surface asperities of the softer metal in contact would undergo plastic deformation. Suitable thermal contact conductance (TCC) models, available in the public domain, were used to evaluate the conductance for the valve/seat and seat/cylinder head interfaces. Finally, a FE thermal model of the test rig has been developed with a view to assess the quality of the calculated TCC values for the valve/seat and seat/head interfaces. The results of the thermal analysis have shown that predicted temperatures at chosen control points agree with those measured during tests on thermometric seats with an acceptable level of accuracy, proving the effectiveness of the used TCC models.
80

Common leisure activities of elementary school age Kansas farm children and their requirements for space in the home

Sullivan, Ann Marie. January 1956 (has links)
Call number: LD2668 .T4 1956 S94 / Master of Science

Page generated in 0.0607 seconds