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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.
161

Vertikální distribuce atmosférického aerosolu v mezní vrstvě atmosféry / Atmospheric aerosol vertical distribution in boudary layer

Dočekalová, Veronika January 2015 (has links)
Particulate matter (PM) air pollution is one of the most important topics in the field of environmental protection, and coal strip mining is a significant source of coarse atmospheric aerosol. In order to implement appropriate regulations to improve air quality, we need to identify the major sources of pollution. PM is usually measured in a ground-based manner and its dispersion is only modelled. Therefore, the objective of this study was to measure concentrations of coarse aerosol in the atmospheric boundary layer above the area of the coal strip mine through experimental airborne measurements and to estimate pollution contribution of mining to the surroundings. Measurements were carried out from November 11 to November 26, 2012, at Vršany coal mine, Czech Republic. An electrically powered airship was used with a specially designed gondola carrying aerosol monitors DustTrak DRX and P-Trak. Temperature and relative humidity data were also recorded. Repeated flights were performed at several heights above mine edge level. PM1-10 and GPS data were recorded every second. Average airship velocity ranged from 6 to 7 ms-1 . Flight measurements were also compared to ground-based measurements of PM10 and meteorological data. Weather during our measurements was characterised by low temperatures, high relative...
162

A Keynesian Politics: Stimulation of Power through Insecurity / A Keynesian Politics: Stimulation of Power through Insecurity

Bayramov, Vugar January 2017 (has links)
Expansion Policies by applying Keynes' key concepts on how market ought to expand or political intervention policies and how it is related to state's political expansion. I refer to it
163

Analysis, Simulation And Design Of Series Resonant Converter For High Voltage Applications

Nathan, Biju S 12 1900 (has links) (PDF)
No description available.
164

Návrh a realizace projektu pro vytvoření online marketingu Event teamu společnosti Unifer o.p.s / The Project Design and Implementation of Event Team's Online Marketing in Unifer o.p.s

Drápal, Dušan January 2015 (has links)
This master’s thesis describes the use of project management for a design and implementation of the project to create web portal for event team of the company UNIFER o.p.s. The thesis descibes in detail the pre-project, project and post-project phase according to project management methods.
165

Harmonic Losses in Windings of Inverter-Fed High-Speed PM Motors / Förluster i lindningar av högvarviga PM maskiner med växelriktare

Yang, Yang January 2015 (has links)
This master thesis focuses on the estimation of losses in windings of a high-speed PermanentMagnet (PM) motor. The PM motor studied in this thesis is applied to a nut-runner systemwith specic characteristics such as operating at a high speed (30000 rpm), relatively smallsize and being slot-less. Previously published analytical models for calculation the losses inwindings are discussed in the literature study along with related background theory. Finiteelement method (FEM) 2D is applied in the simulations using FLUX v12. Simulations beginwith several conductors and bundles. Meanwhile, the analytical estimation of those caseswas carried out. The comparisons between results from both sources are discussed. Beforefurther investigations, the way of connection of bundles and conductors and the applicationof symmetrical conditions for following simulations are discussed. Furthermore, the wholewindings with a iron ring and the rotor are simulated step by step in FLUX. Eect of ironmaterial, lamination thickness and base value are investigated. Finally, losses in windingswith various situations are calculated and compared at 10 kHz and 20 kHz. / Detta examensarbete behandlar uppskattning av forluster i lindningarna hos en permanentmagnet(PM) hoghastighets-motor. PM-motorn som studerats i denna avhandling tillhor ettmutterdragarsystem avsett for industriellt bruk. Utmarkande egenskaper for denna ar hoghastighet (30000 rpm), relativt liten storlek och avsaknad av statorspar. Tidigare publiceradeanalysmodeller for forlustberakningar i lindningar diskuteras i litteraturstudien tillsammansmed tillhorande bakgrundsteori. Finita Element Metoden (FEM) 2D anvands i simuleringarna.FEM-studierna har utforts i FLUX v12. Studierna utfors initialt pa era ledareoch buntar parallellt med analytiska uppskattningar for dessa. Resultaten fran bada kallornajamfors och diskuteras. Vidare diskuteras olika mojligheter till anslutning av era ledare ochledarvarv, samt tillampning av symmetriska villkor for vidare simuleringar. Lindningarnasimuleras darefter stegvis tillsammans med en jarnring och rotor. Paverkan av jarnmaterial,laminat-tjocklek och basvarde utreds. Slutligen utfors forlustjamforelser i lindningarna forolika kongurationer vid 10 kHz och 20 kHz. / Buntade, ledare, FEM 2D, forluster, PM motor, yteekt och narhetseekt, vridna, lindningarna
166

Co-Benefits of Global and Domestic Greenhouse Gas Emissions for Air Quality and Human Health

Jason West, J., Zhang, Yuqiang, Smith, Steven J., Silva, Raquel A., Bowden, Jared H., Naik, Vaishali, Li, Ying, Gilfillan, Dennis, Adelman, Zachariah, Fry, Meridith M., Anenberg, Susan C., Horowitz, Larry, Lamarque, Jean Francois 01 January 2017 (has links)
Most co-benefits studies have been conducted on local or national scales. However, we find that for a coordinated international GHG reduction, much of the air quality and health benefits come from GHG reductions in foreign nations. This is particularly true for ozone, which has a longer atmospheric lifetime than PM2.5, and which is affected by methane reductions. Together these findings show that co-benefits for air quality and health are greater when GHG reductions are coordinated with other nations. These results also show that previous co-benefits studies on local or national scale may significantly underestimate the total co-benefits by omitting i.) the benefits of domestic pollutant reductions for regions outside of the domain considered, and ii.) the benefits of foreign GHG reductions if the domestic reduction is coordinated with international action.
167

Oxytocinbehandling vid värksvaghet : förlossningsklinikers PM följsamhet till de nationella riktlinjerna / Oxytocin treatment when labour dystocia : birth clinics guidelines compliance to the national guidelines

Bergström, Eleonor, Palme, Isa January 2020 (has links)
När förlossningsprogressen går långsamt fram eller stannar av helt kan barnmorskan använda sig av läkemedlet Oxytocin® för att framkalla tätare och mer intensiva värkar och på så sätt uppnå progress i förlossning. Oxytocin® är ett potent läkemedel som när det används felaktigt kan ge allvarliga komplikationer för mor och barn. I Sverige togs nationella riktlinjer för oxytocinbehandling vid värksvaghet fram år 2011. Barnmorskan har även lokala riktlinjer att förhålla sig till i sitt dagliga arbete. Studier har visat att oxytocinbehandling sker på ett ostrukturerat sätt i Sverige. Syftet med studien var att undersöka Sveriges förlossningsklinikers PM följsamhet till de nationella riktlinjerna framtagna år 2011 gällande oxytocinbehandling vid värksvaghet. Studien utgjordes av en kvantitativ, komparativ metod med en deskriptiv ansats, där urvalet resulterade i insamlade data från 43 av landets 44 förlossningskliniker. Ett instrument för dataanalys framtogs där samtliga PM jämfördes mot den text som var formulerad i de nationella riktlinjernas föreslagna PM och presenterades genom deskriptiv statistik. Resultatet visade på en variation i följsamhet i de lokala PM:en till de nationella riktlinjerna. Fem klinikers PM överensstämde med de nationella riktlinjernas PM på samtliga punkter. Ytterligare fyra klinikers PM överensstämde på alla punkter förutom gällande riktlinjer kring dokumentation. Knappt två tredjedelar av klinikerna överensstämde till 75 procent eller mer av de punkter som jämfördes i instrument för dataanalys. Ett fåtal klinikers följsamhet var 25 procent eller lägre. Vidare ansågs varken de nationella eller lokala riktlinjerna vara reviderade utifrån den senaste forskningen och evidensen. Studiens slutsats var att kliniker bör se över sina riktlinjer gällande oxytocinbehandling vid värksvaghet för att kunna erbjuda födande kvinnor i Sverige en jämlik och patientsäker vård.
168

Analysis of Ambient Fine Particulate Matter, PM <sub>2.5</sub> , in Pittsburgh Using Time-Series Techniques and Meteorology

Zubkova, Galina 04 August 2003 (has links)
No description available.
169

Performance Evaluation of Wet Metal Plate Electrostatic Precipitator

Bharmal, Huzefa A. January 2005 (has links)
No description available.
170

Towards Sustainable Braking: Effects of Alternative Ingredients on the Tribological Properties of Friction Materials

Carlevaris, Davide 26 July 2024 (has links)
The most important safety device for commercial vehicles is the brake system. It has to satisfy multiple requirements such as braking performance, wear resistance and low noise production. In the last years, a further requirement has been gaining increasing attention: their particulate matter emission. Indeed, brake systems are one of the most relevant sources of non-exhaust traffic-related emission PM. These emissions have been shown to negatively affect both the environment and the human health, urging authorities to take legislative action. This work is focused on improving the sustainability aspects of brake friction materials. This was done by following two different approaches, both of which involved the use of alternative ingredients in the friction material composition. The new ingredients were chosen based on their properties while also considering aspects related to an eventual industrial application. The first approach involved the use of a natural ingredient, rice husk, as an ingredient in the composition of friction materials; whereas the second approach dealt with the substitution of the conventional phenolic resin binder with benzoxazine resins. The tribological and PM emission properties of friction material samples produced using these ingredients were investigated via tribological testing, and were correlated to the results of the characterization analyses that were performed on the worn surfaces, on the collected emitted particles, and on the newly adopted ingredients themselves. Rice husk is a widely available byproduct of the agricultural industry, and possesses some peculiar properties related to its considerable inorganic content that separates it from the other lignocellulosic materials. Friction materials modified with rice husk were tested with a Pin-on-Disc tribometer and with a reduced-scale dynamometric bench while also monitoring their PM emission. Overall, the adoption of rice husk showed promising results, preserving the friction material coefficient of friction, PM emission and wear resistance. However, when higher temperatures were reached, a loss of performance and durability was observed. Nevertheless, this temperature range was above that associated to common LDV brake system operation, which this application is targeted to. Benzoxazine resins are a relatively new class of binders that display some attractive properties when compared to the conventionally used phenolic resins, such as more forgiving storage conditions, improved thermal stability and customizability of their properties. Two of the simplest representatives of the benzoxazine resin family were hereby adopted. An initial characterization of the thermal behaviour of the resins was first carried out to design the production process of the friction materials containing them. Friction materials bound by benzoxazine resins and by a commercial phenolic resin were tested by Pin-on-Disc and reduced-scale dynamometric bench testing while monitoring their PM emission production. The substitution of phenolic resin with benzoxazine resin as friction material binder proved to be successful, leading to lower wear of the samples, which would translate to a lower environmental impact.

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