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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.
221

Vibrodiagnostika asynchronního motoru / Vibrodiagnostics of induction motor

Mašin, Dominik January 2015 (has links)
This thesis is dealing with measuring and evaluation of vibration signal. Vibration measurement is one of the most important operation for correct and fluent machinery service, not only from economical point of view but also because of security. Status monitoring of electric machine is a key to detect damaged parts and it is giving us an opportunity to avoid unexpected outages and failures in production. My work describes basic concepts and principals of vibration measurement. Asynchronous motor measurement and its evaluation is performed in practical part.
222

Dosage des polluants NO et CO par imagerie de fluorescence induite par laser dans les écoulements réactifs / Probing of NO and CO pollutants in reactive flowfields by planar laser-induced fluorescence

Gautier, Pierre 19 December 2017 (has links)
La thèse consiste à développer une technique d'imagerie quantitative de concentration de polluants dans les écoulements réactifs. Il s'agit d'une part de développer l'imagerie de fluorescence sur NO. Un modèle de fluorescence à n niveaux a été développé pour calculer l'évolution de la fluorescence avec la température, concentration des espèces et pression. Ce modèle a été validé avec des mesures de fluorescence et d'absorption obtenues dans une cellule optique fonctionnant jusqu'à 800 K et 20 bar puis dans un brûleur laminaire haute-pression. De ce modèle a été définie une stratégie permettant la mesure de la distribution instantanée de NO dans une flamme stratifiée. Une étude similaire pour détecter CO a été ensuite initiée. Des mesures de fluorescence à deux photons ont été obtenues dans la cellule et dans une flamme plate atmosphérique. Les résultats montrent que cet outil est opérationnel, répondant à un besoin pour l'amélioration des performances des systèmes de propulsion. / This PhD work is to develop a quantitative imaging technique for measurements of the concentration of pollutants in reactive flows. On one hand, the concern was to develop the NO fluorescence imaging technique. For this purpose, an n-level fluorescence model was first developed to calculate the behavior of fluorescence signals with temperature, species concentration, and pressure. Then this model was validated with fluorescence and absorption measurements acquired in an optical cell up to 800 K and to 20 bar and in a high-pressure laminar burner. From this model, a strategy used to measure the instantaneous NO distribution in a stratified flame was defined. Then, a similar study to detect CO with fluorescence was then investigated. Two-photon fluorescence measurements were performed in the optical cell and in a flame. The results make clear that the spectroscopic diagnostic becomes operational with the need to improve the performances of propulsion systems.
223

Molekulární diagnostika ptačích schistosom při nákaze přirozených i náhodných hostitelů / Molecular diagnostics of bird schistosomes during the infection of natural and accidental hosts

Šteiger, Vladimír January 2018 (has links)
Bird schistosomes of the genus Trichobilharzia are known as causative agents of hyper-immune skin reaction called cercarial dermatitis (swimmer's itch). They use pulmonary water snails from family Lymnaeidae as the intermediate host and mostly anatid birds as the definitive host. The first larva, miracidium, actively moves in water environment, penetrates the snail and develops to the mother sporocyst. Then the daughter sporocysts are formed and migrate to the hepatopancreas of the snail where the high number of cercariae is assexually produced. Cercariae leave the intermediate host, actively move in a water and penetrate the skin of definitive host. Within a host body they mature and lay eggs. Cercariae can penetrate also the mammalian skin, including human, where they are immediately eliminated by the immune system of the host, which is followed by inflammatory reaction. Until now, for humans, there is no effective method enabling to differ cercarial dermatitis from other hyper-immune skin reactions and for birds the reliable diagnostic method of trichobilharziasis is missing. The main aim of this thesis was to use the molecular methods for diagnostic of bird schistosomes infection in natural (ducks) and accidental hosts (mice, human). For optimization, the conventional PCR was used for detection...
224

Vztah vybraných kondičních schopností a výkonnosti ve vodním slalomu (kategorie C1) / The relationship between selected conditional abilities and performance in white water slalom (category C1).

Busta, Jan January 2019 (has links)
The aim of the study was to identify the relationship between selected fitness skills and the performance demonstrated in nomination races (NR) to the Czech Republic national team (NT) and for the Olympic Games. At the same time, we wanted to determine the optimal level of conditioning assumptions and define a model single-canoe sportsman. We were also searching to determine the differences between Senior NT and Junior NT. The research sample (n=17) of the Czech highest competitions series (Czech Cup) participated in testing to determine level of strength, endurance and partly speed assumptions. There were also measured anthropometric parameters (body dimensions and composition) in detail. Testing took place only 5 weeks before NR. The condition indicators were subsequently correlated with the NR performance. For indicators for which significant and at least moderate correlation were found, the possibility of performance prediction was also found. The highest correlations with performance were found in case of on-water sprints: 20m (rs=0,65), 40m (rs=0,86, resp. rs=0,62), 80m (rs=0,58) and 200m (rs=0,795). The on-water sprints are the only indicators, which could be possibly used for the NR performance prediction. In multiple regression of the 2 40m and 1 200m sprints was found high determination...
225

High Speed Laser Diagnostics for Bioagent Defeat Applications

Alex D Brown (8088821) 06 December 2019 (has links)
<div>Recent interest in tailoring energetic materials designed to combat biological weapons agents (BWAs) has resulted in significant effort to produce and test these munitions. These energetic materials may contain agent defeat additives that enhance the capability of a munition to destroy BWAs through chemical methods in addition to heat. However, quantifying levels of agent and biocidal species and their interaction is difficult, and efforts have primarily focused on either ex-situ culturing of exposed bioagent simulants or in situ laser absorption measurements. These experiments are valuable for exploring long term agent defeat and line of sight averaged defeat. What these experiments do not provide, however, is in-situ, spatio-temporally resolved imaging in the reaction zone. To address this gap, this work develops the use of in-situ, high speed, two-dimensional optical diagnostics of fireballs and biological weapons agents simulants (BWA-S).</div><div> </div><div> Planar laser induced fluorescence (PLIF) and laser scattering have been conducted in situ. PLIF of both iodine vapor and BWA-S has demonstrated the ability to qualitatively observe species concentration in fireballs. The application of simultaneous techniques provides imaging of multiple parameters, which is invaluable to the further study of BWA-S and agent defeat interactions. These studies also provide the framework for future work in moving towards quantitative measurements, including the development of absorption and fluorescence models.</div>
226

Imunitní odpověď u kriticky nemocných pacientů / The Immune response in critically ill patients

Melichová, Jana January 2010 (has links)
Cardiosurgery is a potent activator of the immune response similar to sepsis in critically ill patients. Therefore the differential diagnostics of infectious and non-infectious etiology plays an important role. The aim of the study was to compare the biomarkers in the diagnostics of patients after cardiosurgery and in septic patients. 24 patients fulfilling criteria of sepsis and 8 patients after cardio surgery were involved in the study. We demonstrated higher specificity and sensitivity of PCT in comparison with CRP at diagnostics of sepsis. sTREM-1, expression of TREM-1 on monocytes, TREM-1 on granulocytes and the number of FoxP3+T regulatory lymphocytes do not provide a reliable differential diagnostics of infectious and non-infectious etiology of examined group of the patients. The number of lymphocytes in patients with sepsis is a useful parameter at this diagnostics. Cardiosurgery represent a significant impulse for the evocation of the systemic inflammatory response of non-infectious etiology.
227

Motorická výkonnost dětí staršího školního věku / Fitness of 12 - 15 age children

Pěkný, Marek January 2020 (has links)
: Title: Motor performance of secondary school children Objectives: Assess the level of motor performance of secondary school children. Methods: Using motor tests, I have examined the motor performance of secondary school children in the comon class and in the class with extended physical education. The testing took place in the gym of the secondary school and at the athletic stadium as part of physical education lessons. For the results analyses I have used the following characteristics: arithmetic mean, maximum, minimum, standard deviation, variance and variation range. I compared the measured results with UNIFITTEST 6 - 60 scales. I compared the results of pupils from the common class with the measurements Pávek (1977), Máchová (2009) and Zapletalová (2011). I compared the results of pupils from the class with extended physical education classes besides scales UNIFITTEST 6 - 60 with measurements of Kraus (2007), Máchová (2009) and Kůta (2016) Results: The thesis has confirmed the hypothesis that pupils from the class with extended physical education have better results in all tests than the pupils from the comon class. The hypothesis that pupils from the extended physical education class will not have a significantly lower level of performance compared to Máchová 2009 or Kraus 2007 was...
228

Experimental and theoretical study of PAH and incipient soot formation in laminar flames

Li, Zepeng 04 1900 (has links)
Emissions of soot and polycyclic aromatic hydrocarbons (PAHs) from incomplete burning of hydrocarbon fuels pose a great threat to the environment and human health. To reduce such emissions, a comprehensive understanding of their evolution process is essential. In this work, a series of research studies were conducted to evaluate sooting tendencies and to experimentally and theoretically develop PAH mechanisms. The sooting tendencies of oxygenated fuels were quantitively investigated in counterflow diffusion flames. Sooting limits are described by critical fuel and oxygen mole fractions, measured with a laser scattering technique. The addition of dimethyl ether displays non-monotonic behavior on sooting tendencies at elevated pressures, which is attributed to the chemical effect from kinetic simulations. The tendency of incipient soot formation of other oxygenated fuels (e.g., alcohol, acid, ether, ketone, and carbonate ester) was also assessed, using a similar approach. As the precursor of soot, PAH measurement using laser induced fluoresecnce was implemented to track the evolution processes from PAHs to incipient soot. Developing a PAH mechanism is essential to the understanding of soot formation; however, PAH formation and its growth process are not well understood. Based on previous research, PAHs with 5-membered rings are abundant in flames. Therefore, the growth of PAHs with 5-membered rings was investigated, using acenaphthylene (A2R5) as the example. The density functional theory (DFT) and the transition state theory (TST) were adopted to calculate potential energy surfaces and reaction rate coefficients. The existence of 5-membered rings appreciably impacts PAH production by facilitating the formation of planar PAHs with C2H substitution, thereby improving existing PAH mechanisms. In PAH mechanisms, the thermochemistry properties are not all calculated, but are hypothesized to be equal to those of a similar structure. The simulation accuracy of the hypothesis is explored here by discussing the sensitivity of the thermochemistry parameters in flame simulations. The group additivity method utilizing THERM codes is used to calculate thermochemistry properties. PAH loading affects the sensitivity of thermochemistry properties to both flame temperature and product yields. These results show that either accurate thermochemistry properties, or reverse reaction rates should be provided in the mechanism to improve simulation accuracy.
229

Diagnostics for joint models for longitudinal and survival data

Singini, Isaac Luwinga 14 March 2022 (has links)
Joint models for longitudinal and survival data are a class of models that jointly analyse an outcome repeatedly observed over time such as a bio-marker and associated event times. These models are useful in two practical applications; firstly focusing on survival outcome whilst accounting for time varying covariates measured with error and secondly focusing on the longitudinal outcome while controlling for informative censoring. Interest on the estimation of these joint models has grown in the past two and half decades. However, minimal effort has been directed towards developing diagnostic assessment tools for these models. The available diagnostic tools have mainly been based on separate analysis of residuals for the longitudinal and survival sub-models which could be sub-optimal. In this thesis we make four contributions towards the body of knowledge. We first developed influence diagnostics for the shared parameter joint model for longitudinal and survival data based on Cook's statistics. We evaluated the performance of the diagnostics using simulation studies under different scenarios. We then illustrated these diagnostics using real data set from a multi-center clinical trial on TB pericarditis (IMPI). The second contribution was to implement a variance shift outlier model (VSOM) in the two-stage joint survival model. This was achieved by identifying outlying subjects in the longitudinal sub-model and down-weighting before the second stage of the joint model. The third contribution was to develop influence diagnostics for the multivariate joint model for longitudinal and survival data. In this setting we considered two longitudinal outcomes, square root CD4 cell count which was Gaussian in nature and antiretroviral therapy (ART) uptake which was binary. We achieved this by extending the univariate case i based on Cook's statistics for all parameters. The fourth contribution was to implement influence diagnostics in joint models for longitudinal and survival data with multiple failure types (competing risk). Using IMPI data set we considered two competing events in the joint model; death and constrictive pericarditis. Using simulation studies and IMPI dataset the developed diagnostics identified influential subjects as well as observations. The performance of the diagnostics was over 98% in simulation studies. We further conducted sensitivity analyses to check the impact of influential subjects and/or observations on parameter estimates by excluding them and re-fitting the joint model. We observed subtle differences, overall in the parameter estimates, which gives confidence that the initial inferences are credible and can be relied on. We illustrated case deletion diagnostics using the IMPI trial setting, these diagnostics can also be applied to clinical trials with similar settings. We therefore make a strong recommendation to analysts to conduct influence diagnostics in the joint model for longitudinal and survival data to ascertain the reliability of parameter estimates. We also recommend the implementation of VSOM in the longitudinal part of the two-stage joint model before the second stage.
230

New Strategies of Antifungal Therapy in Hematopoietic Stem Cell Transplant Recipients and Patients With Hematological Malignancies

Leather, Helen, Wingard, John R. 01 September 2006 (has links)
Invasive fungal infections (IFIs) are associated with considerable morbidity and mortality among high-risk individuals. Outcomes for IFI historically have been suboptimal and associated with a high mortality rate, hence global prophylaxis strategies have been applied to at-risk populations. Among certain populations, fluconazole prophylaxis has reduced systemic and superficial infections caused by Candida species. Newer azoles are currently being evaluated as prophylaxis and have the potential to provide protection against mould pathogens that are more troublesome to treat once they occur. Global prophylaxis strategies have the shortcoming of subjecting patients to therapy that ultimately will not need it. Targeted prophylaxis has the advantage of treating only patients at highest risk using some parameter of greater host susceptibility. Prophylaxis strategies are most suitable in patients at the highest risk for IFI. For patient groups whose risk is somewhat lower or when suspicion of IFI occurs in patients receiving prophylaxis, empirical antifungal therapy is often employed following a predefined period of fever. Again this approach subjects many non-infected patients to unnecessary and toxic therapy. A more refined approach such as presumptive or pre-emptive therapy whereby treatment is only initiated upon positive identification of a surrogate marker of infection in combination with clinical and radiological signs will subject fewer patients to toxic and expensive treatments.

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