• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 81
  • 27
  • 15
  • 8
  • 8
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 199
  • 34
  • 22
  • 13
  • 11
  • 11
  • 10
  • 10
  • 9
  • 9
  • 8
  • 8
  • 8
  • 8
  • 8
  • 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.
81

Jeunesse et actions environnementales en région PACA, enjeux et partenariats / Youth and environmental actions in the PACA region, issues and partnerships

Morice, Coline 08 December 2017 (has links)
Cette recherche s’attache aux pratiques de nettoyage et d’enlèvement des déchets en bordure de routes dans les Alpes-Maritimes (France). La réflexion proposée porte sur la déterritorialisation et/ou la reterritorialisation des déchets dans les lieux et sur « l’esthétique de la disparition ». Les résultats émanant d’enquêtes ethnographiques – menées auprès des élus et techniciens du Conseil Général du 06 et des membres d’une association de jeunes : « les Rikikibians » – sont l’occasion d’explorer leurs manières respectives ou communes d’agir avec les déchets sur l’environnement. Cette recherche entend revisiter la monographie, en tentant la « science nomade » de Deleuze et Guattari. Partant d’une approche ethnologique du sensible, il s’agit d’évaluer la relation entre les hommes et les déchets dans les usages politiques et sociaux de l’espace-nature contemporain. Le déchet, en tant que chose entre matière et substance, objet manipulé et objet de manipulation, est envisagé suivant son inscription dans le monde du sauvage et dans ses manières d’habiter l’abandon. Le déchet est analysé dans sa valeur praxique plutôt que dans sa valeur signe, dans la pratique plutôt qu’en termes de symbolique. Au-delà du rejet, l’accent est mis sur le détachement et plus largement sur les processus de subjectivation à l’oeuvre dans « l’apprentissage par corps de savoir-comment » avec les déchets. / This research attempts to look at the cleaning and waste removal practices along the roads in the Alpes-Maritimes (France). The reflection involves the deterritorialisation and/or reterritorialisation of waste in areas and on the “esthetic of disappearance”. The results from ethnographic investigations – which were conducted with elected officials and technicians of the General Council of 06 and members of a youth association : "the Rikikibians" – are an opportunity to explore their respective or common ways of acting with waste on the environment. This research intends to revisit the monograph, trying “nomadic science” of Deleuze and Guattari. From a sensitive ethnological approach, it is to assess the relationship between humans and waste in the political and social uses of contemporary natural-spaces. Waste, as something between material and substance, as manipulated object or object of manipulation, is considered following its inclusion in the world of the wild and in its ways of living the abandonment. Waste is analyzed in praxis value rather than in sign value, in practice rather than in symbolic terms. Beyond the reject, the emphasis is put on the detachment and more broadly on the processes of subjectivation at work in the “know-how body learning” with waste.
82

Astrochémia negatívnych iónov - Laboratórne štúdium / Negative Ion Astrochemistry - a Laboratory Study

Jusko, Pavol January 2013 (has links)
A B S T R A C T Presented work focuses on experimental study of anion interaction with neutral particles at temperatures relevant for astrophysics. Anion H− , important for molecular hydrogen creation, and O− as a possible source of water are investigated. The temperature dependence of reac- tion rate coefficients from 10 to 150 K for reactions H− + H → H2 + e− and O− + H2 → H2O + e− has been determined. The energy distri- bution of electrons produced in the latter reaction at 300 K has also been acquired. These studies have been performed on two experimen- tal setups, which are presented together with the theory of operation, construction details, calibration, and supporting test measurements.
83

THE ROLE OF WATER PURITY IN EMULSIFICATION AND REMOVAL OF OIL FROM SOLID SURFACES

Tsompou, Andriani January 2021 (has links)
Detergents are broadly used in our everyday life for cleaning and washing procedures. They are however, a source of water pollution and can have a negative effect on human health and the environment. To reduce their negative impact, a new trend of using only pure water for washing and cleaning applications is being implemented. However, a scientific basis needs to be established first, as the mechanisms and the effectiveness of this method are not fully understood. In this work, we aim to investigate the effect of water purity on the removal of oil from surfaces and the stability of colloidal systems. To do that, two purified water grades are compared with non-purified tap water and 10 mM NaCl solution. Results from measurement of oil film mass before and after water contact and Quartz Crystal Microbalance with Dissipation (QCM-D) indicate that purified water grades can wash a surface more efficiently than non-purified water grades. Contact angle measurements show that pure water facilitates the cleaning process while spreading of oil on plastic surfaces indicates that electrostatic interactions have an important role in the system. Visual observations of o/w emulsions, show that purified water grades redisperse the oil better. We hypothesize that the mechanism behind the cleaning and washing without detergents relies on the electrostatic interactions. To further investigate the effect of salt on cleaning mechanisms, we performed zeta potential measurements. Results indicate that salt has a negative effect on the stability of the particles.
84

Structural Control of Thermal Fluid Circulation and Geochemistry in a Flat-Slab Subduction Zone, Peru

Scott, Brandt E. 01 May 2019 (has links)
Hot spring geochemistry from the Peruvian Andes provide insight on how faults, or fractures in the Earth's crust, are capable of influencing fluid circulation. Faults can either promote or inhibit fluid flow and the goal of this study is test the role of a major fault, such as the Cordillera Blanca detachment, as a channel for transporting deep fluids to the surface. Hot springs are abundant in the Cordillera Blanca and Huayhuash ranges in Peru, and several springs issue along the Cordillera Blanca detachment, making this region an ideal setting for our study. To test the role of the Cordillera Blanca detachment, hot springs were sampled along the trace of the fault (Group 1), the western edge of the Cordillera Blanca (Group 2), the eastern side of the Cordillera Blanca (Group 3), and in the Cordillera Huayhuash (Group 4). Water and dissolved gas samples were collected from a total of 25 springs and then analyzed for an array of geochemical parameters. Distinct fluid chemistries from Groups 1 and 2 suggest that the Cordillera Blanca detachment and adjacent minor faults to the west intersect at depth and provide a preferential flow path for deep fluid circulation. Understanding the influence of faults on fluid flow is essential for many disciplines (e.g. oil exploration, hydrology), and this work demonstrates that fluid geochemistry is an excellent tool for assessing the role of faults on fluid distribution.
85

Psychological Detachment in Preservice Teaching

Streit, Jessica M.K. January 2018 (has links)
No description available.
86

Breaks that break the burnout spiral

Smith, Claire E. 01 May 2019 (has links)
No description available.
87

Scrolling for Success? The Impact of Social Media Microbreaks on Perceived Work Productivity and Psychological Detachment from Work

Plath, Carina, Christiansen, Tabea January 2023 (has links)
Completing tasks and reaching goals at work depletes employees’ energy, motivation, and attentional resources, resulting in negative stress and fatigue experiences. Taking microbreaks from work may help recover from work demands and replenish these resources by positively affecting employee well-being and performance. Therefore, this study seeks to understand the potential benefits of personal social media use as a specific microbreak activity that has become increasingly popular in recent years for employee recovery and productivity during working hours. More specifically, the engagement in social media microbreaks (SMMB) was hypothesized to positively predict both employees’ psychological detachment and perceived productivity. Cross-sectional survey data from 193 white-collar workers were collected and analyzed using linear regression. The results of this correlational study revealed that while engagement in SMMB activities positively predicted psychological detachment, perceived productivity was not found to be associated with SMMBs when holding employees’ general engagement in social media and socially desirable responding constant. Exploratory analyses showed that these relationships may be contingent on demographic, individual, and work (break) characteristics. These findings challenge the predominant negative connotation of using social media at work among employers and by contributing to a growing body of evidence suggesting the restorative nature of microbreaks. Yet, this research underlines the necessity for further research to elucidate the boundary conditions for effective (social media) microbreaks.
88

Systemic Quinolones and Risk of Adverse Reactions: Integrating Evidence from Clinical and Epidemiological Evidence Streams

Taher, Mohamed Kadry 31 May 2021 (has links)
Quinolones are a group of antibiotics that have gained significant popularity on a global scale since the end of the last century. This popularity was predominantly based on their proven potency, broad coverage against a wide range of bacteria, in addition to possessing a favorable pharmacologic profile. Whereas quinolone-associated adverse reactions are generally tolerable and self-limiting, some reactions have generated heightened concerns due to their serious nature, which have resulted in label changes or even market withdrawal in some instances. This thesis investigates the association between quinolone antibiotics and two adverse reactions of an acute and serious nature: acute liver failure and retinal detachment. Each adverse reaction is investigated through integrating evidence from three studies utilizing different designs based on data from different sources, with each source offering a unique perspective on this issue. The first study type (chapter 2 for acute liver failure ‘ALF’ and Chapter 5 for retinal detachment ‘RD’) analyzes spontaneous reports submitted to the US Food & Drug Administration (FDA) adverse event reporting system database. Chapters 3 and 6 systematically identified all relevant (published and unpublished) clinical trials for occurrences of ALF and RD, respectively, among trial participants. Finally, chapters 4 (ALF) and 7 (RD) involved case-control analysis of a major US database of electronic health records for nearly 70 million inpatients admitted to more than 500 hospitals between 2000 and 2016. The FAERS analysis revealed a positive ALF signal with ciprofloxacin and a marginal signal for RD with moxifloxacin. Examination of the evidence from clinical trials revealed only two cases of ALF, one associated with gemifloxacin and one with moxifloxacin. No cases of RD were reported in any of the identified clinical trials. Primary analyses of the Health Facts® data revealed no overall association between quinolones and the risk of ALF or RD. However, elevated risk was identified in some subgroups, including African Americans (ALF, RD), Caucasians (ALF), women (ALF, RD), men (ALF), those ≤60 years of age (ALF) or 56-70 years of age (RD), and those with no or few comorbidities (ALF). Evidence from analyses of data from spontaneous reports and clinical trials provided some evidence for an elevated risk of ALF or RD following the systemic administration of quinolone antibiotics. Some evidence of elevated risk was also identified in the case-control analyses of inpatient EHR records. Findings from our six epidemiologic studies are in line with current advisories by FDA and Health Canada.
89

Aerodynamics of Particle Detachment from Surfaces: A Numerical Study

Palakurthi, Nithin Kumar January 2017 (has links)
No description available.
90

QUASI-STATIC BUBBLE SHAPE ANALYSIS IN THE DEVELOPMENT OF MODELS FOR ADIABATIC AND DIABATIC GROWTH AND DEPARTURE

Lesage, Frédéric J. 04 1900 (has links)
<p>In an effort to better understand the physical mechanisms responsible for pool boiling heat transfer, an analytical model is developed that better describes the changing shape and size of a growing bubble. Indeed, any analysis of thermal transport due to nucleate pool boiling requires bubble frequency predictions which are intimately linked to bubble volume. The model is developed and validated for quasi-static bubble growth due to gas injection and for bubble growth due to vaporization within the heat-transfer controlled growth regime; it highlights the need to include the asymmetric nature of growing bubbles when modeling bubble growth.</p> <p>In addition, a numerical study of quasi-static bubble shape for both adiabatic bubble growth and vapour bubble growth provides insight into the dependence the bubble shape evolution has on the Bond number. In so doing, bubble profiles generated from a numerical treatment of the Capillary equation are benchmarked to quasi-static gas injected bubble formations and to heat-transfer controlled vapour bubble formations.</p> <p>The numerical treatment of bubble shape evolution leads to a simplifying bubble geometry for low Bond number applications. The geometric model accounts for bubble shape transformation throughout the bubble growth cycle including the necking phenomenon. An analytical model of quasi-static adiabatic bubble growth is accordingly developed based on the proposed low Bond number geometric model; it is coupled with a geometric detachment relation and a force balance detachment criterion that are dependent on the Bond number. The resulting predicted bubble growth characteristics, such as profile, volume, centre of gravity and aspect ratio, are validated with the benchmarked numerical treatment of the problem.</p> <p>Furthermore, the low Bond number geometric model is applied to bubble growth due to vaporization. In order to solve the mass-energy balance at the vapour bubble interface, a spherical surface area is commonly assumed. This leads to the need for correction factors and provides little insight into the physical mechanism responsible for bubble shape. In this study, the transitioning shape of a vapour bubble is considered in the integral analysis of the interfacial mass-energy balance. The model predicts the following bubble growth characteristics: profile, volume, centre of gravity, and aspect ratio.</p> / Doctor of Philosophy (PhD)

Page generated in 0.0755 seconds