ABSTRACT This thesis is concerned with a technical modification of design of the electrical power systems for Modřice and its surroundings. The thesis describes a basic theoretical distribution of the electricity network and the distribution network itself. Following chapters are devoted to the development and construction of the HV networks and to the methods and ways of calculating the steady operation of the network. These methods are then used in the computational programs that are presented in the next chapter of this paper. The aim of the practical part of the thesis is to first determine the current state of the network in the given location. Furthermore, several modifications are proposed according to the requirements for increasing the power consumption or connecting the new supply places. The proposed modifications are further assessed for the different operating conditions. The result is a network that is functional, operational and reliable. The whole analysis is carried out in the PAS DAISY Off-line V4 Bizon computing program.

Disertační práce se zabývá chováním a odezvou elastohydrodynamického (EHD) mazacího filmu za neustálených provozních podmínek. V úvodní části práce jsou shrnuty poznatky z oblasti EHD mazání; od jeho historie, přes základní mechanismy mazání a používané experimentální metody, až po nedávno publikované studie zaměřené na transientní podmínky. Hlavním cílem práce bylo experimentálně objasnit vliv provozních parametrů a reologických vlastností maziv na chování mazacího filmu v bodovém kontaktu při jeho nárazovém zatěžování a vystavení příčným vibracím. Za tímto účelem byla vyvinuta laboratorní zařízení umožňující měření rozložení mazacího filmu a tření za kontrolovaných nestacionárních podmínek. Experimenty odhalili zásadní roli přibližovacích a zatěžovacích rychlostí na formování stlačených mazacích filmů při nárazovém zatěžování. Výsledky byly srovnávány s nedávným teoretickým řešením. Bylo ukázáno na jeho nedostatky, jež byly následně odstraněny implementací empirických vztahů zohledňujících reologii maziv. V případě příčných vibrací byly nalezeny hranice selhání mazacího filmu a určeny vztahy popisující vliv příčných vibrací na centrální tloušťku filmu a její fluktuace jednotně pro všechny maziva. Závěrečná část práce poskytuje nový pohled na reologii maziv pomocí inovativního přístupu měření třecích reakcí maziva současně ve dvou směrech kontaktu za podmínek příčných vibrací. Tyto původní výsledky rozšiřují pochopení mechanizmů EHD mazání a mohou být použity k dokonalejším návrhům strojů, a vylepšit tak jejich účinnost, spolehlivost a životnost.

Currently, the nodal areas of Neznášov substation and Krasíkov substation, which belong to ČEZd distribution network 110 kV – East, are operand as separate units. In the defined setting, each nodal area comprises of two 400/110 kV transformers. In the case of failure of the transformer T401 or T402, the criterion N-1 for twenty percent of the rated output is not met. Such problem can be solved by parallel operation of nodal areas of Neznášov substation and Krasíkov substation. The principal as well as practical aim of this thesis is to interconnect the bridge operated connection in separated areas into parallel/loop operation of nodal areas (supplied by 400/110 kV transformers). Computing software is used to calculate the steady state and short-circuit conditions in the distribution network 110 kV for separate and parallel operation of mentioned nodal areas. Power flow analysis is aimed at assessment and evaluation of voltage conditions, transformers loading (400/110 kV and 110/vn) as well as 110 kV lines loading. Obtained short-circuit indices is used to examine short-circuit, withstand capability of the 110 kV substation. Finally, benefits as well as drawbacks of the separate and parallel operation are compared and evaluated. If necessary, the technical arrangements are proposed/designed in order to allow parallel operation of nodal areas Neznášov substation and Krasíkov substation.

The goal of this Master thesis is to design a power convertor for BLDC motor 48V/2kW. Emphasis is placed on the small dimensions of the final printed circuit board. Therefore, power SMD transistors STL135N8F7AG are used in small packages PowerFlat 5x6. To reduce area of the PCB, electrolytic capacitors are mounted on a separate board, which is located above the main PCB. Small high-capacity 22F/100V ceramic capacitors are used in the DC-LINK as well. They are located as close as possible to the power SMD tranzistors. Control logic will be provided by microprocesor STM32G474RE. High resolution timer HRTIM1 is used. The first part of this thesis is devoted to the brief description of BLDC motor construction and driving. Next parts are focused on the design itself.

Knowlege of elektric power, power dissipation and voltage conditions in every single segments and elektric power system nodes is necessary for operations control and designing of another elektric power system expansion. In this Thesis, we will handle with steady state of system calculation using PAS-DAISY-OFF LINE software, solving various power network configurations and their verification.

This thesis deals with the steady operation and short-circuit conditions in the 110 kV network E.ON in a separate and parallel operation of nodal areas of Otrokovice substation and Sokolnice substation. The theoretical part is devoted to the calculation of steady state high-voltage systems using Newton's iterative method, transient phenomena that may occur in the power system short-circuit calculations and theories. The practical part deals with the actual calculations of steady state and short-circuit conditions in a separate and parallel operation of nodal areas Sokolnice-Otrokovice, which were calculated using the dispatching program. These calculations are then evaluated for possible use of involvement in actual operation. At the end there are suggestions on operational measures in the network 110 kV.

Freshwater lakes constrain its methane (CH4) emissions through CH4 oxidation. CH4 includes three carbon (C) isotopes; the stable isotopes 12C,13C and the unstable and more uncommon isotope 14C. Methanotrophs (i.e. methane oxidizing bacteria) oxidize the lighter isotope more rapidly. Changes in relative isotopic composition can therefore be used to calculate how much CH4 is oxidized in a system. This study investigates an annual CH4 oxidation in a freshwater lake. Water samples and bubbles of CH4 gas were collected once a month, from March to November, in lake Gundlebosjön. The CH4 gas was separated from the water samples with a headspace extraction technique. The concentration and isotopic composition of CH4 was analyzed in a cavity ring down spectrometer. The isotopic data was used in two mathematical models, based on open-steady state and closed systems. It was found that the stable isotope method to estimate CH4 oxidation was only useful during periods when clear concentration and isotope differences could be observed in the water column. CH4 oxidation could only be estimated in the water column in August, and in the surface layer in June and July. / Utsläppen av metan (CH4) från sötvattensjöar begränsas genom CH4 oxidation. Det är två stabila kolisotoper som dominerar i CH4; 12C och 13C. Den ostabila kolisotopen 14C finns även i CH4, men den är mer ovanlig i naturen. Metantrofer (metanoxiderande bakterier) oxiderar den lättare kolisotopen snabbare. Förändringar i isotopsammansättningen kan användas för att beräkna hur mycket CH4 som oxideras i ett system. Denna studie undersöker en årlig CH4 oxidation i en sötvattensjö. Vattenprover och bubblor av CH4-gas samlades en gång i månaden, från mars till november, i Gundlebosjön. CH4 gasen separerades från vattenproverna med en ”headspace extraction” teknik. Koncentration och isotopsammansättningen av CH4 analyserades i en ”cavity ring down spectrometer”. Isotopdata användes i två matematiska modeller, baserade på öppet-stabilt tillstånd och stängt system. Den stabila isotopmetoden för att uppskatta CH4 oxidation var endast användbar under perioder då tydliga skillnader i koncentrationen och isotopsammansättningen kunde observeras i vattenpelaren. CH4 oxidation kunde endast uppskattas i vattenpelaren i augusti, och i vattenpelarens ytskikt i juni och juli.

<p>Early processes following photon absorption by the photosynthetic pigment-protein complex photosystem I (PS I) have been the subject of decades of research, yet many questions remain in this area of study. Among the trickiest to investigate is the role of the PS I reaction center’s (RC’s) two accessory (A_‑1) chlorophyll (Chl) cofactors as primary electron donors or acceptors, oxidizing the special pair (P₇₀₀) of Chls or reducing a nominal primary electron acceptor (A₀) Chl in the first electron transfer step. Such processes, which occur on a picosecond timescale, have long been studied via ultrafast spectroscopy, though difficulty lies in distinguishing among signals from early processes, which have similar lifetimes and involve many identical pigments. In this work, we used steady-state and ultrafast optical pump-probe spectroscopies on PS I trimers from wildtype and mutant strains of the cyanobacterium <i>Synechocystis</i> sp. PCC 6803 in which an asparagine amino acid residue near A_‑1 had been replaced with methionine on one or both sides of the RC. We also conducted an identical set of experiments on mutants in which A₀ was similarly targeted, as well as studied the effects on the A₀ absorption spectrum of a third category of mutations in which a peripheral H‑bond to A₀ was lost. Steady-state absorption spectroscopy revealed that many of these mutations caused mild Chl deficiencies in the light-capturing antenna of PS I without necessarily preventing organisms’ growth. More importantly, we determined that contrary to certain hypotheses, A_‑1 is the most likely true first electron acceptor, as reasoned from observing rapid triplet state formation in double A_‑1 mutants. We also concluded from non-additive detrimental effects of single-side mutations that if one RC branch is damaged at the level of A₀ or A_‑1, electron transfer may be redirected along the intact branch. This may help explain the conservation of two functional RC branches in PS I over many generations of natural selection, despite the additional cost to organisms of manufacturing both.</p>

Abstract Purpose: To compare the frequency specific Cortical Auditory Evoked Potential (CAEP) and the chirp-evoked 40 Hz Auditory Steady State Response (ASSR) with equivalent residual noise levels for behavioural threshold prediction in adults with normal hearing and with SNHL. Method: The study tested 23 adults with normal hearing and 20 adults with SNHL. The participants were aged between 18–65 years. A repeated measures within- participant descriptive design was used to collect the quantitative data. The participants underwent behavioural pure tone, CAEP and ASSR testing on the same day. Results: Similar CAEP difference scores across frequencies for the participants with normal hearing (mean=12.32-14.40 dB) and with SNHL (mean=10.00-16.47 dB) were measured. However, for the ASSR difference scores across frequencies slightly smaller difference scores were measured for the participants with SNHL (mean=10.17-17.30 dB) than for the participants with normal hearing (mean=11.74- 17.14 dB). CAEP thresholds were significantly closer to the behavioural pure tone thresholds at 500 (p=0.028; mean absolute difference 14.40 dB) and 2000 (p=0.016; mean absolute difference 12.56 dB) Hz for participants with normal hearing. In participants with sensorineural hearing loss, CAEP and ASSR thresholds were measured at similar sensation levels and were not statistically different (p>0.05). Conclusion: For the purpose of threshold estimation, representing the auditory function to the level of the auditory cortex the CAEP was closer to the behavioural hearing thresholds than the 40 Hz ASSR at all frequencies except at 4000 Hz, regardless of the hearing sensitivity. Keywords: Auditory steady state response (ASSR), Cortical auditory evoked potential (CAEP), Auditory evoked potential (AEP), Residual noise, Signal to noise ratio (SNR), objective threshold estimation, awake adults. / Dissertation (MA (Audiology))--University of Pretoria, 2019. / Speech-Language Pathology and Audiology / MA Audiology / Unrestricted

京都大学 / 0048 / 新制・論文博士 / 博士(医学) / 乙第13133号 / 論医博第2137号 / 新制||医||1024(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 溝脇 尚志, 教授 妹尾 浩, 教授 鈴木 実 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM