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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.
91

JLab E12-14-012 (e,e'p) cross section measurements for Ar and Ti

Gu, Linjie 01 July 2021 (has links)
In recent years, many high precision experiments were carried aiming to improve the accuracy on the measurements of the neutrino oscillation parameters. One of the main source of uncertainty for neutrino oscillation experiments is due to the lack of a comprehensive theoretical description of neutrino-nucleus interactions. The US Deep Underground Neutrino Oscillation Experiments (DUNE) will deploy a series of detectors using Liquid Argon Time Projection Chambers (LArTPCs). A fully consistent parameter-free theoretical neutrino-nucleus scattering model on argon does not exist. The first step towards constructing a nuclear model will be to determine the energy and momentum distribution of protons and neutrons inside the argon nucleus. The JLab E12-14-012 experiment performed at Jefferson Laboratory in Newport News, Virginia, ran in 2017 and will provide such measurements in Argon and Titanium using electron scattering (e,e'p). The data collected by the experiment covers a wide range of energy transfers and also includes several other targets like aluminum and carbon. This Ph.D. thesis will present details of the JLab E12-14-012 experiment, together with first data analysis results of the exclusive (e,e'p) data on Argon and Titanium. / Doctor of Philosophy / Neutrino, a tiny, nearly massless particle was discovered about one hundred years ago. Neutrinos are everywhere around us. If you put your hands under the sunlight, each second, there will be about one billion neutrinos pass through them. As the second most abundant particle in the universe, it is extremely important to study neutrinos as they affect many fundamental aspects of our lives. For examples, neutrinos could help us study the nucleons' structure, and how the matter evolved from one particle to many. Since neutrinos are produced in nuclear fusion processes from the sun and stars, we could also understand the sun and universe better by studying the property of neutrinos. Neutrinos have three flavors, and they could change flavors through neutrino oscillation. Measuring the neutrino oscillation parameters is one of the priority tasks for the physics society. Lots of experiments were carried aiming to enhance the understanding of neutrinos and improve the neutrino oscillation measurements accuracy. The most exciting and famous one is the Deep Underground Neutrino Experiment (DUNE) that will be carried in Fermilab. DUNE is an accelerator based experiment that will use Argon as the neutrino target to study the neutrino oscillation. In order to improve the measurement accuracy of the oscillation parameters for the DUNE, a well defined theoretical model for neutrino interaction on Argon is needed. Thus, the JLab E12-14-012 experiment was performed in Hall A at Jefferson Lab in Newport, News, VA to help people get ready for this through electron scattering. The primary goal of this experiment is to measure the electron-nucleus interaction through (e,e$^\prime$p) reactions and further develop a electron-nucleus model to be used in the future neutrino experiments. This thesis will present an overview of the experimental setup and results from the data analysis.
92

Search the decay of the B meson to two leptons at the Belle Experiment

Williams, Kimberly Marie 01 February 2016 (has links)
The set of decays known as B⁰ → l⁺l⁻ are exceedingly rare. This thesis details procedures developed to optimize signal extraction and improve the upper limit on the measured branching fraction. When applied to 85 million BB events collected at the Belle experiment in Tsukuba, Japan, the resulting upper limits on branching fractions were 8.8×10⁻⁸ for B⁰ → e⁺e⁻, 1.0×10⁻⁷ for B⁰ → μ⁺μ⁻, and 8.5×10⁻⁸ for B⁰ → e±μ∓" at the 90% confidence level. / Ph. D.
93

Experiment and Tradition: A Builder's Thoughts

Corday, Peter David 05 August 1999 (has links)
The following thesis has attempted to investigate the possibilities of an architecture based in tradition and in innovation. An architecture that neither imitates nor mimics, but one that results from construction and the nature of materials used rather than from the application of decorative elements to disguise the structure of the building. The success of a project results from the architect's conceptual understanding of the traditions of the region in which the project exists, informed by local traditions yet not illustrating a revivalist form of vernacular construction. / Master of Architecture
94

Podpora využívání experimentálního systému Vernier na českých školách / Development of Czech teaching materials for the Vernier experimental system

Vogalová, Naděžda January 2011 (has links)
The aim of this thesis is to summarize already published tutorials for experiments with the Vernier lab system and to write new tutorials respecting requirements and specifics of the Czech educational system. Six new detailed tutorials were prepared. All of them were, or would be, published on the Internet web site of The Framework Education Programmes (www.rvp.cz). Following tutorials were written: Bulb flickering, Warm-up of a compact fluorescent lamp, Relation between illumination and distance of the light source, Relation between illumination and number of filters, Why is salt used in the winter on the roads, Photochromic glasses. Each experiment is accompanied by a classification with respect to The Framework Education Programmes and by requirements for The State High School Leaving Exam (``maturita'').
95

In-situ photocatalytic remediation of organic contaminants in groundwater

Lim, Leonard Lik Pueh January 2010 (has links)
This research is about the development of a photocatalytic reactor design, Honeycomb, for in-situ groundwater remediation. Photocatalysis, typically a pseudo first order advanced oxidation process, is initiated via the illumination of UVA light on the catalyst, i.e. titanium dioxide (TiO2). In the presence of oxygen, highly reactive oxidising agents are generated such as superoxide (O2-), hydroxyl (OH.-) radicals, and holes (hvb+) on the catalyst surface which can oxidise a wide range of organic compounds. The target contaminant is methyl tert butyl ether (MTBE), a popular gasoline additive in the past three decades, which gives the water an unpleasant taste and odour at 20 μg L-1, making it undrinkable. This research consists of three major parts, i.e. (i) establishing a suitable catalyst immobilisation procedure, (ii) characterisation and evaluation of reactor models and (iii) scale up studies in a sand tank. TiO2 does not attach well onto many surfaces. Therefore, the first step was to determine a suitable immobilisation procedure by preparing TiO2 films using several potential procedures and testing them under the same conditions, at small scale. The coatings were evaluated in terms of photocatalytic activity and adhesion. The photocatalytic activity of the coatings was tested using methylene blue dye (MB), which is a photocatalytic indicator. A hybrid coating, which comprises a sol gel solution enriched with Aeroxide TiO2 P25 powder, on woven fibreglass exhibited the best adhesion and photocatalytic activity among samples evaluated. Thus, it was used to produce immobilised catalyst for this research. Consequently, the immobilisation procedure was scaled up to synthesize TiO2 coatings for the potential photocatalytic reactor design. The photocatalytic activity of the coatings produced from the scaled up immobilisation procedure were reasonably comparable to that produced at small scale. Due to the UVA irradiation and mass transfer limitations, photocatalytic reactors are typically compact in order to maximise their efficiency to accommodate high flows, particularly in water and wastewater treatment. In the case of groundwater, however, the treatment area can span up to meters in width and depth. Groundwater flow is significantly lower than that of water treatment, as the reactor design does not need to be compact. Considering both factors, a photocatalytic reactor design of hexagonal cross-section (Honeycomb) was proposed, in which the structures can be arranged adjacent to each other forming a honeycomb. A model was constructed and tested in a 4 L column (cylindrical) reactor, using the MB test to characterise the reactor performance and operating conditions. This was followed by a hydraulic performance study, which encompasses single and double pass flow studies. The single pass flow study involves the photocatalytic oxidation (PCO) of MB and MTBE, while the double pass flow study was focused on the PCO of MTBE only. The double pass can simulate two serially connected reactors. Single pass flow studies found that the critical hydraulic residence time (HRT) for the PCO of MB and MTBE is approximately 1 day, achieving up to 84 % MTBE removal. Critical HRT refers to the minimum average duration for a batch of contaminant remaining in the reactor in order to maintain the potential efficiency of the reactor. Double pass studies showed the reactor can achieve up to 95 % MTBE removal in 48 hours, and that reactor performance in the field of serially connected reactors can be estimated by sequential order of single pass removal efficiency. In groundwater, there are likely to be other impurities present and the effects of groundwater constituents on the reactor efficiency were studied. The MTBE PCO rate is affected by the presence of organic compounds and dissolved ions mainly due to the competition for hydroxyl radicals and the deactivation of catalyst surface via adsorption of the more strongly adsorbed organic molecules and ions. Despite the presence of organic compounds and dissolved ions, the reactor achieved about 80 % MTBE removal in 48 hours. A double pass flow study showed that the overall efficiency of the photocatalytic reactor in the field can be estimated via sequential order of its efficiency in a single pass flow study using the actual groundwater sample in the laboratory. A sand tank was designed for the simulation of the clean up of an MTBE plume from a point source leakage using the 200 mm i.d. Honeycomb I prototype. Honeycomb I achieved up to 88.1 % MTBE removal when the contaminated groundwater flowed through (single pass) at 14.6 cm d-1. The critical HRT for Honeycomb I was also approximately 1 day, similar to that in the column reactor. The response of MTBE removal efficiency towards flow obtained in the column reactor and sand tank was generic, indicating that the reactor efficiency can be obtained via testing of the model in the column reactor. The presence of toluene, ethylbenzene and o-xylene (TEo-X) decreased the MTBE removal efficiency in both the sand tank and column reactor. The same set of catalyst and 15 W Philips Cleo UVA fluorescent lamp was operated for a total of about 582 h (24 d) out of the cumulative 1039 h (43 d) sand tank experiments, achieving an overall MTBE removal efficiency of about 76.2 %. The experiments in the column reactor and sand tank exhibited the reliability of the immobilised catalyst produced in this research. This research demonstrates the potential of Honeycomb for in-situ groundwater remediation and also proposes its fabrication and installation options in the field.
96

Kriminalistický experiment / Criminalistic Experiment

Mottlová, Šárka January 2020 (has links)
Criminalistic experiment Abstract The diploma thesis "Criminalistic experiment" deals with the analysis of selected methods of criminalistic practice in the Czech legal branch and Czech criminalistic practice. It contains two parts, theoretical and practical. The theoretical part is based on an analysis of the available literature. It focuses on the conceptual methods of the "criminalistic experiment" performed by experts, describes the different methods from other special methods of proof and specifies the various stages of the experiment. The first chapter defines the term criminalistic experiment as the use of experimental methods in criminalistics. Furthermore, the subchapters describe the various types of criminalistic experiment, from the informal tactical experiment, through the actions of a forensic expert called a professional experiment, to the actions of forensic experts called an investigative experiment. The first chapter also deals with a special form of investigative experiment, where the experiment is performed directly by a judge, the so-called judicial experiment. The second chapter of the diploma thesis tries to define the fundamental differences between the investigative experiment and other special methods of proof such as confrontation, recognition, reconstruction and on-site...
97

Experiment inom NO-undervisning: Vad säger den senaste forskningen?

Svensson, Per, Lindahl, Johan January 2020 (has links)
Denna kunskapsöversikt undersöker vad det senaste decenniets forskning har belyst kring arbete med experiment i naturorienterande undervisning riktat mot åk 4-6. En systematisk informationssökning i ett flertal databaser via Libsearch resulterade i 13 artiklar som utifrån förutbestämda kriterier vidare granskades. Några huvudsakliga teman som berör ämnet kunde hittas i dessa artiklar: Möjliga former av bedömning av experiment, stödstrukturer för elever i arbete med experiment, virtuella kontra verkliga experiment och nivå av lärarstyrning. Resultatet visade att ett flertal olika former av bedömning är valida för att bedöma elevers kunskaper om den vetenskapliga processen som ligger till grund för välfungerande experiment och att konkretiserade delmoment då är ett villkor. Liknande tydlighet i beskrivning av processen är också en användbar stödstruktur för elever mitt i arbetet med experiment. Virtuella experiment visar sig ha fördelar framför verkliga experiment under vissa förutsättningar och vise versa. Nivån av lärarstyrning beror på vilket steg i progressionen mot självständigt undersökande arbete eleverna befinner sig på, men även vilket lärandemål aktiviteten har. Riktar sig undervisningen mot naturvetenskapligt innehåll kan en högre nivå av lärarstyrning ha större effekt på elevernas kunskap än att elever genomför experimenten själva.
98

Inovovaná souprava pro demonstrační pokusy z elektroniky / Innovated set for demonstrative experiments from electronics

VAŠÍČEK, Petr January 2011 (has links)
The first part of this thesis is focused on the advantages of using the experiments during the physics education and their educational values. Furthermore, some types of experiments, their correct metodology of implementation and some other aspects which should be given an appropriate attention by the teacher are theoretically described. Then, some types of demonstrational sets and their brief history are described. The attention is aimed at the demonstrational set of DIDAKTIK, its content and composition. One chapter is devoted to the research of schools equipment for using the demonstrational experiments of electricity and magnetism and their evaluations. The last part deals with some experiments which can be made within this set, their documentation and evaluation. Further, there were worksheets created for some of these experiments. Two of these sheets were used among primary schools for didactic exploring and the reasults were evaluated.
99

Das Experiment und die Metaphysik : zur Auflösung der kosmologischen Antinomien /

Wind, Edgar. Buschendorf, Bernhard. Falkenburg, Brigitte. January 2001 (has links) (PDF)
Univ., Habil.-Schr.--Hamburg, 1930.
100

Klasický experiment a počítačová simulace při výuce fyziky / A classic experiment and computer simulation in physics teaching

PELC, Vít January 2016 (has links)
The thesis discusses the use of the classical experiment and computer simulation in teaching physics at the elementary school. Paper defines the term experiment focuses on specific types of classic experiment and computer simulation options. A classic experiment and computer simulation in the research section gives associated with motivation for learning in physics classes. In the didactic analysis in teaching physics at inclusion classical experiment and computer simulation evaluates the effectiveness of the selected type of experiment.

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