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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.
411

Konstrukce experimentálního zařízení pro studium mazání okolků kolejových vozidel / Design of Wheel Flange Lubrication Experimental Apparatus

Nepovím, Radovan January 2012 (has links)
The diploma thesis deals with construction design and practical realisation of experimental apparatus for investigation of wheel flange track vehicle lubrication. Experimental apparatus in full-scale uses optical interferometry for investigation of lubrication behaviour in wheel flange contact. It is an innovative approach which has not been used for such experiments so far. The aim of the following measurement with this apparatus is to determine the minimal amount of ecological lubrication in wheel flange contact under certain conditions when there is no lubrication film interruption. The apparatus enables to measure real rail wear. This work contains the apparatus description for the study of wheel flange lubrication, wheel flange contact specifications, the description of its influence on wear and acoustic emission, and a detailed description of the experimental apparatus.
412

Impacts des caractéristiques du peuplement et des cloisonnements sur la biodiversité floristique en forêt de plaine / Effects of stand attributes and skid trails on ground flora diversity in lowland forests

Wei, Liping 26 September 2014 (has links)
Le maintien ou l'amélioration de la biodiversité est un des objectifs importants de la gestion forestière durable. La flore du sous-bois, qui représente la partie la plus diversifiée de la flore dans les forêts tempérées, joue des rôles écologiques importants. Pourtant, elle pourrait être impactée par l'augmentation de la mécanisation de la gestion forestière. A l'échelle de la parcelle, nous avons étudié en forêt de Montargis les effets simples et combinés de caractéristiques du peuplement et de la surface en cloisonnement sur la diversité floristique du sous-bois (richesse et abondance). Les caractéristiques du peuplement (type de peuplement ou surface terrière des essences à étaient les meilleurs indicateurs de la diversité du sous-bois. La surface des cloisonnements avait un effet négligeable. A plus petite échelle – à l’intérieur du cloisonnement – nous avons étudié la réponse statistique de la diversité du sous-bois à la position dans ou hors du cloisonnement, à des facteurs micro-environnementaux (humidité du sol, compaction du sol, lumière) et aux caractéristiques du peuplement. A cette échelle, les meilleurs modèles incluaient pour les groupes écologiques la position par rapport au cloisonnement, l’humidité du sol et/ou la compaction du sol, selon le groupe écologique considéré. Au niveau espèce, la position par rapport au cloisonnement était le facteur dominant. Globalement, les cloisonnements avaient soit pas d’effet soit un impact positif sur la diversité floristique de sous-bois. Ces résultats ont dépendants du contexte écologique et historique de la forêt de Montargis. L’utilisation d’engins plus lourds ou des passages répétés sur une plus longue période pourraient changer ces conclusions. / Maintaining or improving biodiversity is an important goal of sustainable forest management.Ground flora, which is responsible for most floristic diversity in temperate forests, plays multiple important roles in biodiversity but may be impacted by the increasing mechanisation of forest practices. At stand scale, we investigated in Montargis forest the individual and combined effects of tree stand attributes and skid trail area on ground flora diversity. Tree stand attributes (stand type or basal area) were the best indicators of ground flora diversity, depending on the successional traits or light preference of the species group. The effects of skid trail area were negligible. At finer scale, we studied plant response to skid trail disturbance (represented by subplot on and off skid trails), micro-environmental factors (soil moisture, soil compaction, light) and stand attribute (stand type, basal area). The best models for ecological groups included subplot location, soil moisture or soil compaction, depending on which ecological groups (classified by life form, seed bank persistence, light and moisture requirements) the species belonged to. Stand type as a covariate played a significantly important role in fine-scale diversity pattern. Subplot location was the dominant factor at species level. In conclusion, skid trails had either no impact or a positive impact on ground flora diversity. These results are dependent on the context of Montargis forest (ecological and historical), especially that mechanized harvesting is relatively recent. The employment of heavier machines and increased number of passages is likely to happen. This might induce greater soil compaction and negative effects on plant.
413

Estimation of Nutrient Exports Resulting from Thinning and Intensive Biomass Extraction in Medium-Aged Spruce and Pine Stands in Saxony, Northeast Germany.

Knust, Christine, Feger, Karl-Heinz 27 March 2017 (has links)
A growing interest in using forest biomass for bioenergy generation may stimulate intensive harvesting scenarios in Germany. We calculated and compared nutrient exports of conventional stem only (SO), whole tree without needles (WT excl. needles), and whole tree (WT) harvesting in two medium aged Norway spruce (Picea abies L. Karst.) and Scots pine (Pinus sylvestris L.) stands differing in productivity, and related them to soil nutrient pools and fluxes at the study sites. We established allometric biomass functions for each aboveground tree compartment and analyzed their nutrient contents. We analyzed soil nutrient stocks, estimated weathering rates, and obtained deposition and seepage data from nearby Level II stations. WT (excl. needles) and WT treatments cause nutrient losses 1.5 to 3.6 times higher than SO, while the biomass gain is only 1.18 to 1.25 in case of WT (excl. needles) and 1.28 to 1.30 in case of WT in the pine and spruce stand, respectively. Within the investigated 25-year period, WT harvesting would cause exports of N, K+, Ca2+, and Mg2+ of 6.6, 8.8, 5.4, and 0.8 kg·ha−1 in the pine stand and 13.9, 7.0, 10.6, and 1.8 kg·ha−1 in the spruce stand annually. The relative impact of WT and WT (excl. needles) on the nutrient balance is similar in the pine and spruce stands, despite differences in stand productivities, and thus the absolute amount of nutrients removed. In addition to the impact of intensive harvesting, both sites are characterized by high seepage losses of base cations, further impairing the nutrient budget. While intensive biomass extraction causes detrimental effects on many key soil ecological properties, our calculations may serve to implement measures to improve the nutrient balance in forested ecosystems.
414

Kan man skämta om det här? : En kulturanalytisk studie av svensk ståuppkomik / Can you joke about this? : A cultural analysis of Swedish stand-up comedy

Liliequist, Christian January 2020 (has links)
Stand-up comedy has become increasingly popular in Sweden in the late 20th and early 21st centuries. The jokes of stand-up comedians are reflections of contemporary cultural notions and discourses. Stand-up comedy can also be seen as a form a cultural free zone where one is allowed to express oneself in ways that are not possible in other public contexts. In this study I am investigating how Swedish stand-up comedians relate to cultural notions about gender, sexuality, ethnicity/race, places, age, disabilities, social class and mental illness. By applying an intersectional perspective I am able to show how various power structures can interact and strengthen each other. The main empirical material consists of three observations at different stand-up comedy clubs and four interviews with stand-up comedians. By using cultural analysis as an analysis method I am showing how stand-up comedy both reflects and is affected by larger structural patterns and discourses in society. My analysis shows that stand-up comedians are both reproducing and challenging normative cultural notions. A variety of theoretical concepts are used to analyse how standup comedians are joking about prevailing cultural notions. For example am I using gender theories to analyse jokes about notions of gender and sexuality while postcolonial concepts as well as theories about racification are applied in the analysis of jokes connected to cultural notions about race and ethnicity. In some of the jokes different cultural notions are intertwined. Furthermore I am analysing how the stand-up comedians are reflecting over what they are allowed to joke about, depending on their own background and experiences as well as how they are relating to different discourses. Stand-up comedy is still dominated by a masculine discourse that has only recently been challenged by a feminist discourse, which stand-up comedians relate to in different ways. How stand-up comedians navigate between political correctness and the discourse that comedians should be able to joke about everything is also part of my investigation. Finally, I am analysing different comic strategies used by the stand-up comedians in their performances, which affect how they are joking about various cultural notions. Some comedians are joking about themselves in a self-deprecatory way while others invites the audience to join the perspective of an assumed normative community to make jokes about what makes other groups different.
415

Návrh testovacího stavu pro dlouhodobé testování spojek určených pro kolejová vozidla / Design of test rig for long-term testing of couplings intended for railroad applications

Machálek, Ondřej January 2019 (has links)
The master thesis deals with design of test rig for long-term testing of coupling appointed to railway vehicles. At first, there is made a brief research which is related to railway coupling used for transmitting a torque. This is followed by an analysis of the most used power devices to derive real loads conditions of tested couplings. There is chosen the most appropriate conception based on made analysis and it is followed by the description of designed components. There is made a verification of modal properties non-purchased components which is necessary part of the thesis. Numerical modal analysis was performed in ANSYS Workbench software. In the end of the thesis there are included stress-strain analysis of the chosen designed components.
416

Návrh testovacího stavu diferenciálu pro zástavbu v bezdozvukové komoře / Design of the Differential Test Rig for Testing in Anechoic Chamber

Ivanič, Michal January 2020 (has links)
The diploma thesis describes the design of a test stand for experimental determination of vibroacoustic parameters of a part of the powertrain system. Thesis contains a research part, describing the problems of the drive system, vibroacoustics, measuring devices and also the division and the description of test stands. At the same time, the reasons for choosing a closed loop test stand are explained. Thesis also includes the results of analytical calculations and numerical results of FEM methods performed using ANSYS software, as well as drawing documentation of individual parts.
417

Návrh ventilového bloku rekuperačního hydrostatického modulu vozidla / Design of valve block for hydrostatic recuperative module of vehicle

Ranuša, Matúš January 2014 (has links)
The Master`s Thesis deals with design and construction of a valve block for a hydrostatic recuperative module of a vehicle with a direct application on pneu tyred roller AP 240H produced by the AMMANN company. The thesis aims to analyze recovery functions of the valve block in several operating modes of the roller, followed by a selection of the right hydraulic components from the perspective of predefined parameters and pressure differences. Design specifications are based on measurements and mathematical simulations on the experimental stand. The experimental stand for this application has been developed at 1:4 scale as compared to a real vehicle. The thesis includes also design of the supporting console for the module on the frame of the vehicle. The Master`s Thesis is a part of project EUREKA with cooperation Bosch Rexroth.
418

Acheter des fruits et légumes locaux sur mon chemin : analyse de la fréquentation et des premiers effets du Marché solidaire Cadillac

Hébert, Myreille 12 1900 (has links)
Les systèmes alimentaires alternatifs font partie des stratégies prometteuses pour améliorer l’accès aux fruits et légumes (FL) frais des populations défavorisées et mal desservies. Peu de données probantes existent pour saisir leur portée et leur efficacité. Suite à l’implantation d’un kiosque maraîcher à la sortie d’une station de métro de Montréal, cette étude vise à analyser l’évolution de sa fréquentation, du profil de ses utilisateurs et les caractéristiques des utilisateurs rapportant une augmentation de leurs achats de FL au cours des deux premières saisons. Deux sources de données ont été analysées : les données de ventes recueillies par une application de paiement mobile et une enquête répétée auprès des utilisateurs (2016, n=214 ; 2017, n=151). Une augmentation significative de la fréquentation a été observée, les utilisateurs de 2017 achetaient plus au kiosque. Une plus grande proportion d’entre eux le fréquentait hebdomadairement et rapportait une consommation d'au moins 5 FL/jour. Les utilisateurs de 2017 étaient majoritairement plus favorisés qu’en 2016. En 2017, 23% affirmaient acheter davantage de FL, comparativement à 12% en 2016. Les caractéristiques des 23% correspondraient davantage à la population ciblée. Par ailleurs, ils étaient plus susceptibles de fréquenter le kiosque hebdomadairement, de percevoir peu abordables les FL de leur quartier et de ne pas avoir accès à une automobile. Un an après son ouverture, le kiosque affiche un certain succès, mais sa capacité à rejoindre les populations défavorisées est mitigée. Au-delà de l'amélioration de l'accès physique, l’ajout d’incitatifs réduisant les barrières économiques serait plus efficace pour diminuer les inégalités de santé. / Alternative food systems have the potential to enhance physical and economic access to fruits and vegetables (FV) for vulnerable and underserved populations. The evaluation of their scope and their effectiveness requires additional efforts. Following the implementation of a FV stand next to a subway station in Montreal, this study aims to determine the evolution of its attendance, shoppers’ profile and the characteristics of shoppers reporting an increase in their FV purchases between the first and second season. Two sets of data were collected: details of all sales data and on-site surveys (2016, n = 214; 2017, n = 151). A significant increase in attendance was observed: 2017’s shoppers purchased more FV at the stand. A larger proportion of 2017 shoppers frequented it weekly and reported an intake of at least 5 FV / day. However, a larger proportion were wealthier. In 2017, 23 % of shoppers reported an increase of their FV purchases. compared to 12% in 2016. These 23% of shoppers would have characteristics of the originally targeted deprived population. They were also more likely to attend the stand weekly, to perceive FV’s neighborhood unaffordable and not to have access to a car. One-year post-implementation, the FV stand present a potential success. However, its reach to disadvantaged populations is mixed. Beyond improving physical access, include incentive strategies to reduce economic barriers would be relevant in reducing social and health inequalities.
419

Vliv vybraných manuálních technik na statickou a dynamickou posturální stabilitu u studentů fyzioterapie / The effect of chosen manual techniques on static and dynamic postural stability in physiotherapy students

Hrmová, Jana January 2020 (has links)
Title: The effect of chosen manual techniques on static and dynamic postural stability in physiotherapy students. Aims: The main aim of this study is to assess the effect of chosen manual techniques on participants' static and dynamic postural stability. Summary: The study was done from May to December 2019. A total of 100 subjects aged 19-38years took part in the study. Participants were randomly divided into two groups - experimental and control. Postural stability was measured by the following tests: Star Excursion Balance test, Unipedal Stance test, Timed Up and Go test and Sit to Stand test. These standardised measurements were taken before intervention, after intervention and a week from intervention. Experimental group undertook the intervention by manual techniques, which took 20 minutes. Outcomes were written into recording sheets. Final data were processed using Microsoft Excel 2013, IBM SPSS Statistics V26 and TIBCO Statistica 13.3.0. To calculate differences, the following statistical methods were used: Shapiro-Wilk test, independent T-test and Mann-Whitney U test. To measure effect size, Cohen's d was used. The level of statistical significance was determined to α = 0,05. The clinical significance was assessed by these levels: d = 0,2-0,49 (small effect), d = 0,5-0,79 (medium effect),...
420

Designing administrative support systems for healthcare organizations / Att designa administrativa stödsystem för sjukvårdsorganisationer

Berglund, Eric, Danielsson, Olof January 2015 (has links)
In modern healthcare organizations, work is increasingly team-oriented, which puts pressure on information technology to support staff collaborations. Healthcare organizations are lagging behind in the use of IT and often use outdated systems. A reason for this is the long and cumbersome process of IT-procurement. Stand-alone systems can help such organizations be more efficient, and receptive of the latest technologies, while conveying lower risks, and increased chances of successful implementation. Therefore, this study has investigated what problems can be expected, and how to manage them, when designing such systems. The study was conducted at the Department for Reconstructive Surgery at Karolinska University Hospital. Action research was used, and a system supporting the scheduling of doctors was deigned, implemented and evaluated. The study consists of an initial exploratory phase, a design and implementation phase, and an evaluation phase. The findings of this study indicate that the problems that can be expected when developing a stand-alone system at a small specialized healthcare department are: 1) that the hierarchies among staff may lead to failure to accept designs and the designs not taking all stakeholders into account, 2) that the complexity may lead to an inability to identify the real problems and define appropriate design-goals, and 3) that the combination of 1 and 2 hinders a mutual understanding of design-goals, problems, and solutions. To manage the problems, this study suggests the use of participatory design, user centered system design, and a computer supported collaborative work approach, and provides guidelines for using these to reach an effective implementation. / I moderna sjukhus arbetar man allt mer team-orienterat, vilket ställer krav på system och programvara att stödja samarbeten personalen emellan. Inom sjukvården sker anskaffandet av nya tekniker genom om offentlig upphandling, vilka är tungrodda processer som tar lång tid. Detta leder till att många sjukhus har utdaterade system som inte tjänar organisationernas bästa. Genom att anskaffa mindre, fristående system kan mottagligheten för de senaste teknikerna ökas, och med denna kan även en ökad effektivitet av administrativt arbete uppnås, till låg risk och med möjlighet till effektiv implementation. Av dessa anledningar har denna studie undersökt vilka problem som kan förväntas vid utveckling av sådana system, och hur dessa problem kan överbryggas. Studien utfördes på Kliniken för Rekonstruktiv Plastikkirurgi på Karolinska Sjukhuset i Solna. Vi använde oss av aktionsforskning, och utvecklade, implementerade samt utvärderade ett stödsystem för schemaläggningsprocessen på kliniken. Studien består av tre faser: en explorativ fas, en design- och implementationsfas, samt en utvärderingsfas. Resultaten visar på att de problem som kan förväntas när man utvecklar ett fristående system för en specialiserad kirurgklinik är: 1) att hierarkier inom personalstyrkan kan leda till att utformningen av system inte accepteras, och att system inte bistår alla intressenter, 2) att organisationens komplexitet gör det svårt att identifiera de underliggande problemen, och definiera ändamålsenliga målsättningar för utformningen av systemet, och 3) att kombinationen av 1 och 2 hindrar en ömsesidig förståelse för utformningen av systemet, de problem som finns, och hur man kan lösa dem. Vidare visar denna studie att problemen kan överbryggas genom att använda metoder för deltagande design, användarcentrerad design och en modell för synsätt kallad computer supported collaborative work under designprocessen. Vidare tillhandahåller studien riktlinjer för hur dessa metoder och synsätt kan användas för att uppnå en effektiv implementation.

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