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Tidsupplösning vid miljövärdering av fjärrvärme : Kontorsbyggnad med solvärmeproduktion - en fallstudie / Time resolution in environmental assessment of district heatingLätt, Ambjörn January 2015 (has links)
The demand for environmental assessments on buildings and energy consumption is increasing as well as the energy performance requirements for buildings. At the same time it is increasingly common with self-producers of heat and electricity generation. The main purpose with this master thesis is to investigate how time resolution affects the environmental assessment of energy consumption in office buildings connected to district heating (DH). Environmental assessments were done with both attributional LCA and consequential LCA with system expansion. Fortum´s DH system in Stockholm was analyzed and district heating production was simulated in a Matlab-model. Greenhouse gas (GHG) emissions for the production were calculated. The heat demand of the office Gångaren 16 in Stockholm was simulated in IDA ICE. Thereafter the environmental impact in terms of GHG emissions was calculated with data from the assessment of the DH production. The results show that the highest time resolution that should be used for environmental assessment of energy consumption in buildings connected to DH is daily average values, regardless of LCA perspective. Moreover, sufficient results are achieved with yearly average values with attributional LCA. The results for consequential LCA with system expansion show that daily and yearly average values are not sufficient. Since peak production is temperature dependent rather than time dependent it is recommended that DH peak production is environmental assessed by temperature in future work.
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Stanovení charakteristiky atmosférického aerosolu s vysokým časovým rozlišením za účelem identifikace jeho zdrojů / Source apportionment of atmospheric aerosol fraction using by highly time resolved characterisationPokorná, Petra January 2014 (has links)
The effective air quality management in the heavy polluted areas has to be based on high-quality monitoring with properly designed monitoring network and targeted measurements, which provided information required to source apportionment. The thesis aim was to apportion sources of atmospheric aerosol based on highly time resolved data of mass concentration of size segregated aerosol, its temporal and spatial variability, elemental composition, OC/EC and size distribution of carcinogenic polyaromatic hydrocarbons. Sampling campaigns went during winter and summer in small settlement Březno by Chomutov, residential area Ostrava - Radvanice a Bartovice and Mladá Boleslav in the years 2008 - 2010, 2012, 2013. We determined mass concentrations of PM10, PM1-10, PM1.15-10 and PM0.15-1.5 and their size fraction ratios. Based on the size ratios, the source apportionment of fine fraction (PM0.15-1.15) with focus on PM0.34-1.15 is crucial. We examined seasonal and spatial variability of PM10, PM.2.5, PM1 and PM1-10. Based on the examination, we obtained representative highly-time resolved data with regards to season and sampling locality. We analysed dynamic of size distribution of particle-bond eight carcinogenic polycyclic hydrocarbons. Based on the results the source apportionment of PM0.34-1.15 is crucial....
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A New High Voltage Partial Discharge Indicator SystemGul, Ibrahim Oguz 01 June 2006 (has links) (PDF)
In this thesis work, a new partial discharge magnitude indicator with LCD display was designed. This system was implemented in high voltage partial discharge detection and measurement systems. AVRISP In-System programmer is used to program the microprocessors used inside the display unit. The time resolution of the system (one pixel of the display unit) is 4 microseconds. The unit is capable of counting the number of impulses of the input voltage that is coming from the high voltage system within user selectable time intervals. The changeable values of the time intervals are 2, 4, 6, 8 and 10 seconds. It is also capable of showing the maximum value of the impulses in a given time interval. This maximum value is a number changing between 0 and 256. By calibration of the system, it was possible to indicate the discharge magnitudes in picocoulombs.
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Časové rozlišení TileCalu a hledání těžkých dlouhožijících částic / Time resolution of TileCal and searches for heavy metastable particlesPagáčová, Martina January 2012 (has links)
Title: Time resolution of TileCal and searches for heavy metastable parti- cles Author: Martina Pagáčová Department: Institute of Particle and Nuclear Physics Supervisor: Doc. RNDr. Rupert Leitner, DrSc. Supervisor's e-mail address: Rupert.Leitner@cern.ch Abstract: In the present work, the timing of the ATLAS TileCal is stud- ied using the single hadron collision data. The time resolution and also the mean time response depend on the energy deposited in a given cell. The results are compared to the previous analysis with jets and muons. Precise time-of-flight measurement using TileCal can be used to identify the heavy long-lived particles predicted by the models of physics beyond the standard model. Their mass can be reconstructed by combining with the momentum measurement in the ATLAS inner detector. Finally, the mass resolution of an exotic particle with mass M = 600 GeV is estimated. Keywords: ATLAS experiment, TileCal, time resolution, stable massive particles
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Conformational dynamics of G-quadruplex DNA probed by time-resolved circular dichroism / Dynamiques conformationnelles de l’ADN G-quadruplex sondées par dichroïsme circulaire résolu en tempsSchmid, Marco 13 December 2017 (has links)
Les quadruplexes de guanines (G4) sont des structures d’ADN non-canoniques qui résultent de l’empilement hydrophobe de tétrades de guanines, stabilisé par des cations métalliques (tels que Na+ et K+). Il existe aujourd’hui un nombre croissant de preuves expérimentales qui attestent de l’implication des G4 dans d’importantes fonctions cellulaires corrélées à leur mécanisme de repliement/dépliement. Toutefois, très peu d’études ont abordé les aspects dynamiques de leur formation. Aussi, nous avons entrepris l’étude de plusieurs G4 mono-moléculaires à l’aide d’une nouvelle extension d’expériences de saut de température, capable de mesurer la dynamique de dénaturation thermique et de renaturation consécutive de l’ADN, sur une fenêtre temporelle allant de quelques millisecondes aux secondes. Les changements conformationnels ont été sondés par dichroïsme circulaire (CD) résolu en temps, connu pour être très sensible à l’arrangement des guanines dans les G4. Au préalable des études résolues en temps, en collaboration avec DISCO/SOLEIL, nous avons mesuré les spectres CD statiques de différentes séquences G4 présentant des topologies distinctes, comme celles des télomères humains, de l’aptamère de la thrombine ou des promoteurs de c-MYC. Nous avons observé des cinétiques de dénaturation et renaturation biphasiques avec des constantes de temps de quelques centaines de millisecondes et quelques secondes. Ces cinétiques dépendent fortement de l’amplitude du saut de température et de la concentration de cations métalliques. L’ensemble de ces observations suggère l’existence de plusieurs voies de repliement/dépliement des G4 sur des surfaces de potentiel très rugueuses. / Guanine-quadruplexes (G4) are non-canonical DNA structures that result from the hydrophobic stacking of guanine quartets stabilized by metal cations (typically Na+ and K+). There is now an increasing body of experimental evidence of their occurrence in important cell functions correlated to their folding/unfolding mechanisms. However, only few studies have addressed the dynamical aspect of their formation. In this context, we have undertaken the study of several intramolecular G4 with a novel extension of temperature-jump experiments capable to measure the thermal denaturation and the consecutive renaturation of DNA over a time window spanning a few ten milliseconds to seconds. Conformational changes have been monitored by time-resolved circular dichroism (CD), which is known to be sensitive to the chiral arrangement of guanines in the G4 scaffolds.Prior to time-resolved measurements, within the frame of a collaboration with DISCO/SOLEIL, we have performed static synchrotron radiation CD measurements on several short G4-forming sequences, such as human telomere, thrombin-binding aptamer and c-MYC promoter sequences, displaying distinct topologies. Denaturation and renaturation kinetics are found to exhibit biphasic decays with time constants of a few hundred milliseconds and a few seconds, respectively. Those kinetics depend strongly on the amplitude of the temperature jump and the concentration of cations. Taken together these observations suggest the existence of multiple folding pathways on extremely rugged landscapes.
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Accuracy of low voltage electricity distribution network modellingUrquhart, Andrew J. January 2016 (has links)
The connection of high penetrations of new low carbon technologies such as PV and electric vehicles onto the distribution network is expected to cause power quality problems and the thermal capacity of feeder cables may be exceeded. Replacement of existing infrastructure is costly and so feeder cables are likely to be operated close to their hosting capacity. Network operators therefore require accurate simulation models so that new connection requests are not unnecessarily constrained. This work has reviewed recent studies and found a wide range of assumptions and approximations that are used in network models. A number of these have been investigated further, focussing on methods to specify the impedances of the cable, the impacts of harmonics, the time resolution used to model demand and generation, and assumptions regarding the connectivity of the neutral and ground conductors. The calculation of cable impedances is key to the accuracy of network models but only limited data is available from design standards or manufacturers. Several techniques have been compared in this work to provide guidance on the level of detail that should be included in the impedance model. Network modelling results with accurate impedances are shown to differ from those using published data. The demand data time resolution has been shown to affect estimates of copper losses in network cables. Using analytical methods and simulations, the relationship between errors in the loss estimates and the time resolution has been demonstrated and a method proposed such that the accuracy of loss estimates can be improved. For networks with grounded neutral conductors, accurate modelling requires the resistance of grounding electrodes to be taken into account. Existing methods either make approximations to the equivalent circuit or suffer from convergence problems. A new method has been proposed which resolves these difficulties and allows realistic scenarios with both grounded and ungrounded nodes to be modelled. In addition to the development of models, the voltages and currents in a section of LV feeder cable have been measured. The results provide a validation of the impedance calculations and also highlight practical difficulties associated with comparing simulation models with real measurement results.
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Quality assurance of CsI(TI) crystals for the Bâ†aBâ†aâ†r electromagnetic calorimeter, and a Monte Carlo study of the CP-violating channel B'0#â†>##pi#'+#pi#'-#pi#'0 for the Bâ†aBâ†aâ†r......Champion, Theresa Janet January 1999 (has links)
No description available.
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Development and Characterization of Parallel-Plate Avalanche Counters for Nuclear Physics ExperimentsCarlsson, Matthias January 2018 (has links)
Parallel-plate avalanche counters, PPACs, are commonly used to detect fission fragments. The PPAC detects them and mark (very accurately) the time of detection. Such measurements can be used to measure the neutron energy (via time-of-flight) to study neutron-induced fission.This project report provides a method that, together with the discussed improvements, allows the fabrication of good quality PPAC detectors. Several PPACs are manufactured and the electrodes are built from 0.9 µm thick mylar foils which are evaporated with a 40-80 nm thin layer of aluminum.The developed PPACs are characterized with well known radioactive Cf and Am sources (the source characterization also found in this report), and compared against each other. Additionally, the PPAC signal amplitude spectrum are found to follow theoretical expectations with regards to angular dependence, gas pressure and an applied electrode voltage.At a specific applied electrode voltage and range of gas pressures (3-9 mbar), the measured time resolutions are 2.24-1.38 ns. A trend is observed for finer time resolutions at higher gas pressures. / Parallel-plate avalanche counters, PPACs, används ofta för att detektera fissionsfragment. PPAC:en detekterar fragmenten med väldigt god tidsupplösning och således kan PPAC detektorer användas till att mäta neutron energier (mha. flygtidsmetoden), vilka uppmätts för att studera neutroninducerad fission.Det här projektet och den här rapporten beskriver en metod, med föreslagna förbättringar, som möjliggör tillverkning av PPAC detektorer av bra kvalitet. Under projektet har flera PPACs byggts med elektroder gjorda av 0.9 µm tunn mylar förångade med 40-80 nm aluminium. De tillverkade PPAC detektorerna är karaktäriserade med väl kända radioaktiva Cf- och Am-källor (dessa karaktäriseras även i den här rapporten). Detektorerna är sedan jämförda mot varandra och är funna att följa teoretiska förväntningar med avseende på vinkel-, gastryck- och pålagd elektrodspänningsberoende.Resultaten av projektet, som besvarar flera tidigare frågeställningar och bekräftar vissa antaganden, flyttar utsikten och förståelsen framåt för hur PPACs fungerar och vad forskarna kan uppnå med dem.
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Estudo do Sistema Vítreo SNABP (SiO2 Na2CO3 Al2O3 B2O3 PbO2) Nanoestruturado com Pontos Quânticos de PbS e Dopado com Íons Er3+Silva, Carlos Eduardo 22 July 2011 (has links)
Fundação de Amparo a Pesquisa do Estado de Minas Gerais / The SNABP [40SiO2.30Na2CO3.1Al2O3.25B2O3.PbO2 (mol%)] glass system, nanostructured with PbS Quantum Dots (QDs) and/or doped with Er3+ ions, was successfully synthesized by the Fusion Method, when it was subjected to appropriate thermal annealing. The glass transition temperatures (Tg) were obtained by Differential Thermal Analyze (DTA), in which it was possible to define a suitable temperature to be used in the thermal annealing of the synthesized samples. As results of these thermal annealing, the formation and growth of PbS QDs have occurred in the glass environment. The optical properties of samples were investigated by Optical Absorption (OA), Photoluminescence (PL), and Photoluminescence with Temporal Resolution (PLTR). Moreover, the Atomic Force Microscopy (AFM) and X-Ray Diffractometry were employed in study of morphological and structural properties of samples, respectively. The size dispersions of PbS QDs were determined from OA spectra. Once using both the Method and OA data, it was also possible to estimate the average diameters of these nanoparticles, which grow with the increase in annealing time. The characteristic transitions of Er3+ ions were clearly identified in OA spectra. In addition, it was observed that the increase in annealing time of samples had provoked amplification in the overlapping between PL bands of both the PbS QDs and Er3+ ions, as well as with the absorption 4I15/2 -> 4I13/2 of these ions. Thus, the PLTR measurements have confirmed the decrease in lifetime of the 4I13/2 level (of Er3+ ions), with the amplification in the overlapping of PL emissions. Finally, as a main result of this work, it was proved that the SNABP glass system, nanostructured with PbS QDs and doped with Er3+ ions, displays to be quite favorable to the radiative energy transfer process (from PbS QDs to Er3+ ions), as well as the occurrence of stimulated emission of 4I13/2 level. / O sistema vítreo SNABP [40SiO2.30Na2CO3.1Al2O3.25B2O3.PbO2 (mol%)] nanoestruturado com pontos quânticos (PQs) de PbS e/ou dopados com íons Er3+ foi sintetizado com sucesso pelo Método de Fusão, quando submetido a tratamentos térmicos apropriados. As temperaturas de transição vítrea (Tg) foram obtidas por Análise Térmica Diferencial (DTA), em que foi possível definir uma temperatura adequada para ser utilizada nos tratamentos térmicos das amostras sintetizadas. Como resultados desses tratamentos térmicos, a formação e crescimento dos PQs de PbS ocorreram no ambiente vítreo. As propriedades ópticas das amostras foram investigadas por Absorção Óptica (AO), Fotoluminescência (PL) e Fotoluminescência com Resolução Temporal (PLRT). Além disso, a Microscopia de Força Atômica (AFM) e Difratometria de Raios-X (DRX) foram empregadas no estudo das propriedades morfológicas e estruturais das amostras, respectivamente. As dispersões de tamanho dos PQs de PbS foram determinadas a partir dos espectros de AO. Com a utilização do Método e os dados de AO, foi também possível estimar os diâmetros médios dessas nanopartículas, que aumentaram com o aumento no tempo de tratamento térmico. As transições características dos íons Er3+ foram claramente identificadas nos espectros de AO. Em adição, foi observado que o aumento no tempo de tratamento das amostras provocou um aumento na sobreposição entre as bandas de PL dos PQs de PbS e dos íons Er3+, bem como com a absorção 4I15/2 -> 4I13/2 desses íons. Assim, as medidas de PLRT confirmaram o decréscimo no tempo de vida do nível 4I13/2 (dos íons Er3+) com o aumento dessa sobreposição das emissões de PL. Finalmente, como principal resultado deste trabalho, foi comprovado que o sistema vítreo SNABP nanoestruturado com PQs de PbS dopados com íons Er3+ mostrou-se bastante favorável ao processo de transferência de energia radiativa (dos PQs de PbS para os íons Er3+), bem como a ocorrência da emissão estimulada do nível 4I13/2. / Mestre em Física
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