• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 416
  • 104
  • 95
  • 64
  • 58
  • 58
  • 23
  • 20
  • 20
  • 15
  • 12
  • 10
  • 8
  • 5
  • 5
  • Tagged with
  • 1019
  • 209
  • 129
  • 85
  • 66
  • 59
  • 56
  • 51
  • 48
  • 47
  • 42
  • 42
  • 38
  • 38
  • 38
  • 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.
171

Performance and Safety Behavior of Sulfide Electrolyte-Based Solid-State Lithium Batteries

Liu, Tongjie 15 May 2023 (has links)
No description available.
172

Direct Electroless Copper Plating on Glass Mediated by Solution-Phase Deposition of Nucleation and Adhesion Promoters

Miller, Alexander T. 03 September 2015 (has links)
No description available.
173

Persons with functional difficulties as resources in ICT design processes

Persson, Hans January 2008 (has links)
Denna avhandling har sin grund i mina erfarenheter av att arbete med människor som har funktionsnedsättningar. Vanligtvis är denna grupp den sista en producent ser som sina kunder. Det är ganska vanligt att producenter gör olika produkter(produkter och tjänster) för personer med funktionsnedsättningar och en för andra. Om man istället, i designarbetet utgår från synsättet att de flesta personer vid någon tidpunkt och/eller plats har funktionssvårigheter så blir den potentiella kundgruppen större för produkten. Ursprunget för avhandlingen är ett projekt, vilket drevs av PTS (Post och Telestyrelsen), med syfte att identifiera vilka typer av stöd eller anpassningar personer med intellektuella funktionsnedsättningar har för att använda bredbandsbaserade tjänster. Resultatet i projektet pekade ut ett antal svårighetsområden där flertalet av dessa svårighetsområden inte var unika för denna grupp. Utifrån resultat i ovanstående projekt togs det fram en test-, utvärderings- och designmodell (TED-modellen) där ett av stegen använde en ”indikatorgrupp”. Syftet med modellen är att identifiera och ge underlag för att prioritera vilka svårighetsområden det fortsatta designarbetet skall fokuseras på. Indikatorgruppen består av individer med funktionssvårigheter som är relevanta i sammanhanget. Modellen tar vara på möjligheterna i ”design för alla” för att göra att göra bättre produkter för människorna. De empiriska studierna i denna uppsats är gjorda inom två områden. Den första är i ett designsammanhang, där fem olika hemsidor skulle tas fram och den andra är runt en studie av tre olika affärsarbetsplatser, där kassafunktionen var i fokus för studien. Resultatet i denna uppsats pekar ut en möjlig inriktning för en designmetodologi, vars målsättning är att få fram bättre produkter för en större grupp. Utgångspunkten är att använda människors olikheter som en möjlighet och inte som ett problem. Individer med funktionella svårigheter är en resurs för att finna nya innovationer vilket jag har benämnt ”the Lead of Need”. Med detta menar jag att individer med funktionella svårigheter, som har ett behov, en ide för en lösning, men inte har möjlighet att förverkliga denna. Om vi kan organisera en mötesplats för individer med ”the Lead of Need”, designers och utvecklare så har vi skapat ett ”Living lab” för nya innovationer. / This thesis has its roots in my experiences of working with people who have some forms of disability. Usually this group is the last group producers consider as their customers. It is quite common that producers make different products (and services) for individuals with disabilities and for others. If one instead takes the position, in the design work, that most people have some functional difficulties at some point in time or in place, then the potential customer group becomes larger for the product in question. The origin of this thesis is a project run by the Swedish Post and Telecom Agency (PTS), aiming to identify what kind of support or adaptation people with intellectual disabilities needs when using broadband based services. The result of the project pointed out areas of difficulties. Most areas of difficulties were not unique for this group. From the result of the PTS-project, a design and evaluation model (TED-model) was built, where one of the steps involved the use of an “indicator group”. The aim for this step is to identify and give basis for prioritizing areas of difficulty that the continued design work should focus on. The indicator group consists of individuals with functional difficulties relevant in a specified context. This method uses the possibilities of “design for all” as facilitator to design better products for more people. The empirical studies in this thesis were carried out within two areas. The first study was made in a design project, where five different web sites were to be designed, and the second one dealt with three different business workplaces in which the cashier workplaces was in focus. The results of this thesis point out a possible direction of a design methodology, whose objective is to create better products for larger group of people. The starting point is to use people's differences as a possibility for design, and not a problem. Individuals with functional difficulties constitute a resource for finding new innovations, which I have termed “the Lead of Need”. With this I mean individuals with functional difficulties, who have a need, an idea for a solution, but not the possibility to make it happen. If we can organise a meeting ground for individuals with “the Lead of Need”, designers, and developers, we will have created a “living lab” for new innovations. / QC 20101119
174

A single test for the determination of the velocity: time-to-exhaustion relationship

Broxterman, Ryan M. January 1900 (has links)
Master of Science / Department of Kinesiology / Thomas J. Barstow / Purpose: To determine if a single test is accurate in determining the parameters of the velocity: time-to-fatigue relationship, i.e., critical velocity (CV) and a finite distance that can be covered above CV (D`). Methods: Ten healthy subjects completed an incremental test to volitional exhaustion followed by four constant-velocity runs on a treadmill for the determination of CV and D`, as well as an all-out 3-minute test on a track for the determination of end-test velocity (EV) and the distance above end-test velocity (DEV). Eight of the eleven subjects completed a second 3-minute test and one run each at (+) and (-) 95% confidence interval velocities of CV determined from the 1/time model. Results: The group mean 1/time model CV (12.8 ± 2.5 km·h[superscript]-1) was significantly greater than the velocity-time model CV (12.3 ± 2.4 km·h[superscript]-1; P < 0.05), while the velocity-time model W` (285 ± 106 m) was greater than the 1/time model W` (220 ± 112 m; P < 0.05). EV (13.0 ± 2.7 km·h[superscript]-1) and DEV (151 ± 45 m) were not significantly different than the 1/time model CV and W`, respectively. EV was greater than the velocity-time model CV (P < 0.05), while the DEV was significantly less than the velocity-time model W` (P = 0.002). No difference was found for group mean EV or DEV between the two 3-minute tests (P > 0.05), which demonstrated a reliability coefficient of 0.85 for EV and 0.32 for DEV. For the CV (-) 95% run, all subjects reached a steady-state in VO[subscript]2, and completed 900 s of exercise. However, for the CV (+) 95% run, VO[subscript]2 never reached a steady-state, but increased until termination of exercise at 643 ± 213 s with a VO[subscript]2peak close to but significantly lower than VO[subscript]2max (P < 0.05). Conclusion: CV can be accurately determined using a single 3-minute test, while W` is underestimated with this protocol.
175

Simulation of the Geometry Influence on Curvic Coupled Engagement

Nelkov Nyagolov, Dimitar, Abbas, Bashir, Valentinov Genovski, Filip January 2010 (has links)
The thesis is performed in order to improve the curvic coupled engagement of a dog clutch situated in the transfer case of a truck. The dog clutch is used to engage the so called all-wheel-drive system of the truck. If the driver tries to engage the all-wheel-drive when truck’s rear wheels already skid, due to a slippery surface a relative rotational speed in the dog clutch will occur. This relative rotational speed will cause the dog clutch to bounce back of itself before engagement, or to not engage at all. The dog clutch has been redesigned to prevent this. Dynamic simulations using MD Adams have been made for the existing model, for the models created in previous works, and for the new model in order to figure out which of them will show the most stable engagement, at high relative rotational speed. The implemented simulations show that better results can be obtained. Separation into two parts of the disc pushed by the fork, shows that dog clutch’s engagement is faster and more stable, comparing to the original model and the other created models. The new model shows better coupling in the whole range of the relative rotational speed from 50 up to 120rpm.
176

Novel coherent supercontinuum light sources based on all-normal dispersion fibers

Heidt, Alexander Matthias 12 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: The concept of broadband coherent supercontinuum (SC) generation in all-normal dispersion (ANDi) fibers in the near-infrared, visible and ultraviolet (UV) spectral regions is introduced and investigated in detail. In numerical studies, explicit design criteria are established for ANDi photonic crystal fiber (PCF) designs that allow the generation of flat and smooth ultrabroad spectral profiles without significant fine structure and with excellent stability and coherence properties. The key benefit of SC generation in ANDi fibers is the conservation of a single ultrashort pulse in the time domain with smooth and recompressible phase distribution. In the numerical investigation of the SC generation dynamics self-phase modulation and optical wave breaking are identified as the dominant nonlinear effects responsible for the nonlinear spectral broadening. It is further demonstrated that coherence properties, spectral bandwidth and temporal compressibility are independent of input pulse duration for constant peak power. The numerical predictions are in excellent agreement with experimental results obtained in two realizations of ANDi PCF optimized for the near-infrared and visible spectral region. In these experiments, the broadest SC spectrum generated in the normal dispersion regime of an optical fiber to date is achieved. The exceptional temporal properties of the generated SC pulses are verified experimentally and their applicability for the time-resolved study of molecular dynamics in ultrafast transient absorption spectroscopy is demonstrated. In an additional nonlinear pulse compression experiment, the SC pulses obtained in a short piece of ANDi PCF could be temporally recompressed to sub-two cycle durations by linear chirp compensation. Numerical simulations show that even shorter pulse durations with excellent quality can be achieved by full phase compensation. The concept is further extended into the UV spectral regime by considering tapered optical fibers with submicron waist diameter. It is shown that coherent SC spectra with considerable spectral power densities in the usually hard to reach wavelength region below 300 nm can be generated using these freestanding photonic nanowires. Although technological difficulties currently prevent the fabrication of adequate nanofibers, the concept could be experimentally verified by coherent visible octave-spanning SC generation in tapered suspended core fibers with ANDi profile. The work contained in this thesis therefore makes important contributions to the availability and applicability of fiber-based broadband coherent SC sources with numerous high-impact applications in fundamental science and modern technology. / AFRIKAANSE OPSOMMING: Die konsep van breëband koherente superkontinuum (SK) in alles-normaal dispersiewe (ANDi) vesels in die naby-infrarooi, sigbare en ultraviolet (UV) spektrale gebiede word voorgestel en in detail ondersoek. In numeriese studies word eksplisiete ontwerpskriteria vasgestel vir ANDi fotoniese kristal vesel (FKV) ontwerpe wat dit moontlik maak om plat en gladde ultra-breë spektrale profiele te genereer sonder noemenswaardige fynstruktuur en met uitstekende stabiliteit en koherensie eienskappe. Die sleutel voordeel van SK genering in ANDi vesels is die behoud van ’n enkele ultrakort puls in tyd met ’n gladde en saamdrukbare fase distribusie. In die numeriese ondersoek van die SK generering is die dinamika van fase selfmodulering geïdentifiseer as die dominante nie-lineêre effek wat verantwoordelik is vir die nie-lineêre spektrale verbreding. Daar word voorts aangetoon dat die koherensie eienskappe, spektrale bandwydte en saamdrukbaarheid in tyd onafhanklik is van die inset pulsduur vir konstante drywing. Die numeriese voorspellings stem uitstekend ooreen met die eksperimentele resultate wat verkry is met twee ANDi FKVÕs wat optimeer is vir die naby-infrarooi en sigbare spektrale gebied. In hierdie eksperimente is die breedste SK spektrum gegenereer wat tot hede in die normaal dispersiewe regime met ’n optiese vesel behaal is. Die besondere eienskappe van die genereerde SK pulse is eksperimenteel bevestig en die toepasbaarheid vir tyd opgelosde studie van molekulêre dinamika is gedemonstreer. In ’n addisionele nie-lineêre puls kompressie eksperiment is SK pulse verkry in ’n kort stuk ANDi FKV wat in tyd saamgedruk kon word tot sub-twee siklus tydsduur deur liniêre tjirp kompensering. Numeriese simulasies toon aan dat selfs korter pulse met uitstekende kwaliteit behaalbaar is met volledige fase kompensasie. Die konsep is verder uitgebrei na die UV spektrale gebied deur ’n koniese vesel te beskou met sub-mikron diameter. Daar is aangetoon dat koherente SK spektra met noemenswaardige spektrale drywing in die golflengte gebied onder 300 nm, wat gewoonlik as moeilik toeganklik beskou word, bereik kan word deur hierdie vrystaande fotoniese nano-vesels aan te wend. Alhoewel tegnologiese probleme die vervaardiging van voldoende nano-vesels verhinder, kon die konsep eksperimenteel bewys word deur koherente sigbare oktaafspannende SK te genereer in koniese gesuspendeerde kern vesels met ’n ANDi profiel aan te wend. Die werk wat in die tesis vervat is, maak dus belangrike bydraes tot die beskikbaarheid en toepasbaarheid van vesel gebaseerde breëband koherente SK bronne met verskeie hoë impak toepassings in fundamentele wetenskap en moderne tegnologie.
177

All-Polymer Based Fabrication Process for an All-Polymer Flexible and Parellel Optical Interconnect

Yang, Jilin January 2015 (has links)
This thesis proposed and demonstrated a new all-polymer based fabrication process for an all-polymer flexible and parallel optical interconnect cable having a vertical light coupler, which can not only cut down the cost by eliminating metallization process for alignment but also facilitate both in production and application. Throughout the process, polyimide was used as the substrate, coated by Epoclad as claddings, then AP2210B and WPR 5100 were used to fabricate waveguides and 45 degree mirror couplers, respectively. In addition, precisely aligned mirror couplers to waveguides are fabricated by using polymer-based, non-metallic, and transparent alignment marks. Conventional and metallic alignment marks are easy to be detected by camera, when a layer of high reflective material, generally Cr metal, is patterned. However, transparent polymer material is used in this process, as alignment marks made of it which are actually buried phase structures. Therefore, it is hardly to be observed by conventional microscopy system. Hence, to increase the contrast of the alignment marks, I proposed and tested a feature specific alignment camera system for which the shape and depth of the alignment marks are optimized for phase-based imaging, such as phase contrast and Schlieren imaging. The results showed a contrast enhancement of alignment marks image compared to that of a conventional microscopy system. By using the fabrication and alignment process, process for adding waveguides to the structure is identified by using the polymer based alignment marks on the WPR 5100 layer. Mask was made by etch down process using fused silica wafer plate, Cr and AZ 3312 photoresist. At last, the developed and proposed process provides means of all-polymer based fabrication process for a flexible and parallel optical interconnect.
178

CHARACTERISTICS OF ALL-TERRAIN VEHICLES AND THEIR OPERATORS ON KENTUCKY FARMS

Wilson, Jessica L. 01 January 2012 (has links)
All-terrain vehicles (ATVs) were first developed and marketed in the U.S. in the 1970s. They have soared in popularity for occupational and recreational uses since that time. In 2008, there were approximately 10.2 million all-terrain vehicles (ATVs) in use in the United States. In 2001, it was estimated that 23 million Americans rode ATVs; 69% were adults and 31% children (CPSC, 2003). Deaths and injuries from ATVs have increased over time. According to the U.S. Consumer Product Safety Commission, Kentucky led the nation for ATV deaths from 2002-2006, with increasing numbers of fatalities annually. ATV use on farms is increasing across the country because the vehicles provide an efficient and reliable replacement for horses and tractors for farm work, such as checking livestock, feeding, or fence repair. Aging farmers and farmers with physical disabilities can often increase their productivity by using ATVs for their transportation needs on the farm. ATVs also serve as an inexpensive and popular recreational vehicle used by families especially in rural areas. In 2001, there were an estimated 481 ATVs per 1,000 (CI95% ± 27) farms in the southern region of the U.S. A literature review and a descriptive cross-sectional study were conducted. The specific aims of this dissertation were to: 1. Critically analyze the state of the science on ATV-related injury risk factors and explore recreational and occupational use of ATVs on farms. 2. Describe individual characteristics and demographic factors that are associated with ATV ownership and ridership among adult farmers. 3. Describe individual characteristics and environmental factors that are associated with ATV injury on farms. 4. Test models for predicting ATV ownership, ATV ridership, and ATV injury risk factors among adult farmers.
179

Sverigedemokraternas valframgångar 2006 : - En ulv i fårakläder?

Haraldsson, Emma, Neuschütz, Åsa January 2007 (has links)
<p>University of Växjö</p><p>School of Social Sciences</p><p>Bachelor Thesis in Political Science</p><p>Title: “Sverigedemokraternas valframgångar 2006 – En ulv i fårakläder?”</p><p>Author: Emma Haraldsson and Åsa Neuschütz</p><p>Tutor: Emil Uddhammar</p><p>The aim of this study is to explain Sverigedemokraterna’s electoral success in 2006 and the essay assumes that some form of change has occurred. To study this change two hypotheses have been constructed. The first hypothesis concerns the change within Sverigedemokraterna and the second hypothesis concerns the change of the Swedish voters attitudes.</p><p>Kirchheimers catch-all theory is used to explain the change in Sverigedemokraterna. The catch-all theory states that parties have to change their structure to maximise the number of votes. Lipset and Rokkan’s theory about the party system is also used along with Inglehart’s value studies to explain why parties change.</p><p>The tests of the hypotheses are carried out through a text analysis and a statistical survey. The essay concludes that Sverigedemokraterna has not changed very much and that it is mainly an esthetical and not an ideological change. Therefore the first hypothesis has to be falsified. The second hypothesis can be neither falsified nor verified, because the material is too diverse. Further studies are necessary to explain the electoral success of Sverigedemokraterna.</p>
180

Kunden arbetar för sitt eget bästa! : En studie om kundmedverkan inom charterbranschen

Augustesen, Johanna, Gunnarsson, Annica, Olsson, Katrin January 2010 (has links)
<p>Den moderna resenären har allt mer ansvar i köpprocessen utav sin resa, förr låg det hos researrangören att förse kunderna med information och sköta bokningen, något som kunderna idag kan göra själva genom Internet. Många kunder väljer charter då det är ett bekvämt sätt att resa, researrangören agerar försäkran om ett professionellt bemötande samt att personal finns vid deras sida. Vårt intresse fastnade vid den motsägelsen att kunden tar större ansvar i charterreseprocessen samtidigt som de avstår mer och mer från att paketera sin egen resa.</p><p>Syftet med denna uppsats är att kartlägga och analysera kundens roll som medverkande part inom charterbranschen. I undersökningen har vi haft en kvalitativ forskningsansats och utifrån detta antagit ett abduktivt perspektiv där vi använt oss utav den kvalitativa metoden med semi- strukturerade djupintervjuer. Vi har genomfört sju intervjuer med personer som har anknytning till resebranschen, av dessa har sex skett fysiskt och en via telefon. Vi har sedan analyserat svaren och satt dessa i relation till teorin för att komma fram till vår slutsats.</p><p>Vår främsta slutsats är att charterföretagens bild av kundens medverkan bör ändras. Företagen ser idag endast de uppenbara aktiviterna i form av att kunder checkar in på flygplatsen och liknande händelser. I denna uppsats har vi konstaterat att kunder medverkar i större utsträckning än så, de medverkar hela tiden. Företag vill öka den uppenbara kundmedverkan genom att skapa en situation där kundens aktivitet skapar en effektivitet som inte är möjlig när personal sköter hela processen. I vår slutsats har vi även konstaterat att kundernas primära anledning till att åka på charterresor istället för med reguljärflyg, är tryggheten och säkerheten charterarrangörerna tillför processen.</p>

Page generated in 0.0613 seconds