Plume-spacecraft interactions play an important role in the performance and integrity of spacecraft during their missions in space. The study encompasses a thruster’s plume simulation and its impact on spacecraft geometries to understand and predict the effects and consequences of the impingement on spacecraft surfaces, such as erosion, contamination, forces, and torques. The initial focus of the thesis is to simulate an electric thruster current density for both space and vacuum chamber measurements. This estimates the artificial broadening of the plume produced by low-pressure background air particles inside a vacuum chamber. Subsequently, the study adopts a conservative approach by considering a current density obtained from vacuum chamber measurements, which allowed for an evaluation of the potential effects on spacecraft surfaces, thus delivering insights into erosion, contamination, as well as the distribution of forces and torques. The results highlight the importance of considering spacecraft charging in plume interactions, as the surface potential significantly affects the impact of the thruster’s plume on spacecraft surfaces. The outcome obtained throughout this project suggests that the effects of particle impingement on erosion, contamination, forces, and torques in plume-spacecraft interactions are influenced by the thruster location and the spacecraft’s surface potential. It is important to note that additional factors, including thermal effects, radiation, and magnetic fields, which were not addressed in this thesis, may also pose potential threats to spacecraft performance and should be considered in future investigations. / Interaktioner mellan plym och rymdfarkoster spelar en viktig roll i rymdfarkosternas prestanda och integritet under deras uppdrag i rymden. Studien omfattar simulering av en raketmotors plym och dess inverkan på rymdfarkostens geometrier för att förstå och förutsäga effekterna och konsekvenserna av kollisionen på rymdfarkostens ytor, såsom erosion, förorening, krafter och vridmoment. Avhandlingens initiala fokus är att simulera strömtäthet i plymen från en elektrisk raketmotor för både rymd- och vakuumkammarmätningar. Detta uppskattar den artificiella expansionen av plymen som produceras av de molekyler som närvarar i det låga trycket inuti en vakuumkammare. Därefter antar studien ett konservativt tillvägagångssätt genom att överväga en strömtäthet erhållen från vakuumkammarmätningar, vilket möjliggjorde en utvärdering av de potentiella effekterna på ytorna på en rymdfarkost, och därmed leverera insikter om erosion, förorening, såväl som fördelningen av krafter och vridmoment. Resultaten understryker vikten av att överväga laddning av rymdfarkoster i plyminteraktioner, eftersom ytpotentialen signifikant påverkar raketmotorplymens påverkan på rymdfarkostens ytor. Resultatet som erhållits genom hela detta projekt tyder på att effekterna av partikelkollision på erosion, förorening, krafter och vridmoment i växelverkan mellan plym och rymdfarkoster påverkas av raketmotorns placering och rymdfarkostens ytpotential.

Recent advances in plasma-based propulsion systems have led to the development of electromagnetic Radio-Frequency (RF) plasma generation and acceleration systems, called Helicon Plasma Thrusters (HPT). One of the pioneer companies developing this new type of space propulsion is T4i Technology for Propulsion and Innovation s.p.a., with its cutting-edge project called REGULUS, among which this study has been performed. A crucial part of HPT systems is the acceleration region, where, by the means of a magnetic nozzle, the thermal energy of the plasma is converted into axial acceleration and, in turn, into thrust. This study is focused on the numerically simulation of the plasma dynamics in the acceleration stage, using Xenon gas. A three-dimensional full Particle-In-Cell (PIC) simulation strategy is used to simulate the plume in the magnetic nozzle. The code developed for the plasma simulation is based on the open-source software Spacecraft Plasma Interaction Software (SPIS). The code has been conveniently modified and improved, neutrals and collision processes were added to evaluate their impact on the plasma properties. The features added improved the validity of the results, now one step closer to the physical reality. The code has been proven to be an extremely versatile and powerful tool for optimization and adaptation to different mission scenarios. / De senaste framstegen i plasmaframdrivning har lett till utvecklingen Helicon Plasma Thruster (HPT) som kombinerar elektromagnetisk högfrekvent (RF) plasmakälla och ett accelerationssystem. En av företagen som är pionjärer i att utveckla denna nya framdrivningsteknik är T4i Technology for Propulsion and Innovation s.p.a., med dess banbrytande projekt REGULUS, som detta arbete bygger på. En viktig del av HPT-systemet är accelerationsområde där plasmats termiska energin omvandlas till axiell accelleration i en magnetisk dysa. Denna rapport fokuserar på numeriska modelleringen av plasmadynamiken accelerationsområdet vid användning av Xenongasen. En tredimensionell Particle-In-Cell (PIC) simulering används för att studera plasmautflödet i magnetiska dysan. Koden bygger på den öppna mjukvaran Spacecraft Plasma interaction Software (SPIS). Koden har modifierats och förbättrats, en neutral komponent samt kollisionsprocesser har lagts till och deras påverkan på plasmabeteende har studerats. Dessa nya element förbättrade giltigheten av simulerings-resultaten. Nu ett steg närmre den fysiska verkligheten. Koden är ett mångsidigt och kraftfullt verktyg för optimering och anpassning till olika användningsscenarier.

The diploma thesis titled "Selected aspects of domestic violence described in court files and psychological expert opinions" deals with forensic - psychological issues. The theoretical part defines domestic violence, its forms and types. There is also space for individual aspects of domestic violence, including treatises on victims and perpetrators of domestic violence, related myths and consequences. This chapter also covers the issue of how to help. A separate part deals with the court file, its content and composition. The expert opinion, its assignment and content is then devoted to the conclusion of the theoretical part. The empirical part, focused on the examination of selected aspects of domestic violence, was based on an analysis of court files containing the psychological expert opinion in cases of abuse under §198 and §199 of the Criminal code. Keywords: Domestic violence, Court files, Expert witness psychologist, Expert opinion

My thesis deals with auditor's documents. At first, there is written about specific work of auditor and also legislation, which concerns with work of auditor. Subsequently, thesis presents main reasons and importance for leading auditor 's file. In auditor 's file, there is gathered all probative foundations, which proves process of audit in compliance with valid legislation. Practical part of thesis shows interception of audit at real client in auditor 's file. The aim is to submit total process during documentation of audit and shows organization of file, which is followed in auditor 's company.

In the last 30 years, numerical models have been developed to properly analyze Hall eect thrusters (HET),leading to a bridge between analytical prediction/empirical intuition and experiments. For companies in thespace sector, these codes serve to much more than simply simulating the thruster, but it provides a fast, cheapand reliable tool for processes such as validation and verication procedures, as well as for technical developmentof the thruster. During the testing of the thruster, mostly measurements upstream from the thruster exhaustare obtained since the high density plasma inside the channel disturbs any measurement inside the channel. Thisresults in the company knowing about the output of the thruster performance, but having little knowledge aboutthe processes and behavior of the thruster itself. The purpose of this study is to help reduce the uncertainty,using existing software to eectively analyze and understand HETs. Because of the physical nature of theproblem, HET simulations follow a multi-scale approach where the thruster is divided into two regions: insidechannel/near-plume region and far-plume region. To study each zone dierent softwares are typically used.This thesis aims to nd a common ground between both software, coupling them and creating a line of analysisto follow when studying HETs.The present thesis will focus on the analysis of the famous SPT-100. The design of this work can be divided intotwo: an hybrid-PIC simulation with a software focusing on the inside channel and near-plume region, Hallis; andanother hybrid-PIC simulation regarding the plasma plume expansion performed with SPIS-EP. During thisproject both software were mastered. Hallis is investigated, emphasizing the empirical modelling of the electronanomalous transport inside the thruster and its consequences on the output results. A sensitivity analysis isperformed to obtain a good set of the empirical parameters that drive the overall performance of the thrusterand the plasma behavior. Once a good match persist between Hallis and nominal operating conditions, theoutput is used to construct the input injection distributions needed by the plasma expansion software (SPIS).Finally, the plasma plume is simulated and results are compared to in-house experimental data. In this way,one is able to control and understand the nal output directly from the behavior of the thruster. It is importantto mention that due to condentiality reasons, the testing data cannot be fully shown and sometimes only thetrend can be analyzed.As a results of the analysis, it is found that establishing the coupling between softwares is feasible, but Halliscode needs to include some characteristics to fully take advantage of its potential. It is determined that theion denition followed by Hallis is enough to perfectly dene the ion energy distribution as well as generalperformance parameters of the SPT-100 (thrust, ionization eciency, power...), but the poor electron modelgenerates some deviation in the results. SPIS simulations and comparison with testing data suggest that Hallisoutput is not enough to properly match the experimental measurements, especially regarding the ion angledistribution function. According to Hallis, such distribution is too narrow compared to the observed plasmaplume. This problem is found to be caused by the small simulation domain of Hallis. Hence, although couplingof the software is easy, more functionalities of Hallis would allow for a better study and more accurate results.

The aim of this project is to model current volt-age characteristic curves for different plasma conditions (i.eelectron density, electron temperature, ion temperature andplasma potential) that can be found in active auroras. This isdone by simulating the charging of a FFU with a connectedLangmuir probe in the software SPIS. These I-V curves wereused to determine the plasma properties of the auroras in whichthe sounding rockets SPIDER-1 and SPIDER-2 were launched.Through the simulations it was also studied how the differentparameters effects the I-V curves.The results showed that the plasma SPIDER-1 was launchedin most likely had properties close to nominal conditions and forSPIDER-2 there was colder electrons in the plasma. A conclusionthat only the electron temperature affects the shape of the I-Vcurves for the values simulated in this project can be drawnas well as the conclusion that the geometry of the probe doesnot affect the shape of the I-V curves. Another result showsthat electron temperature also affect how the hull of the FFUcharges. A higher electron temperature gives the hull a morenegative charge. / Syftet med detta projekt är att modellera ström-pänningskaraktäristisk kurvor för olika plasmatillstånd som finns i aktiva auroror. Detta görs genom att simulera laddning på en FFU med en ansluten Langmuir-prob i SPIS. Dessa I-V-kurvor används för att bestämma plasma egenskaperna för aurororna sondraketerna SPIDER-1 och SPIDER- 2 skjöts upp i. I-V kurvorna används också för att bestämma hur plasma parametrarna elektron temperatur, jon temperatur och elektrondensitet samt hur probens geometri påverkar I-V- kurvornas utseende. Resultaten visade att den plasma SPIDER-1 blev uppskjuten i troligen hade nominella förhållanden och att den SPIDER-2 blev uppskjuten i troligtvis hade kallare elektroner. En slutsats om att endast elektron temperaturen påverkar formen på IV- kurvorna kan dras, såväl som slutsatsen att probens geometri inte påverkar formen på IV-kurvorna. Ett annat resultat visar att elektron temperaturen också påverkar ytpotentialen på FFUn. En högre elektron temperatur ger FFUn en mer negativ laddning. / Kandidatexjobb i elektroteknik 2020, KTH, Stockholm

This thesis deals with questions connected with the electronification of the judiciary in the Czech Republic majoring in the civil judicial proceeding. The first part focuses on the description of the background of electronization of judiciary in the Czech Republic, benefits and barriers associated with computerization. The author describes the conditions to implement e-justice (which are reform of judiciary, development of information society or technical readiness). Process of electronification of the judiciary is illustrated by introduction of eJustice project. There are disscused three basic elements of e-justice in the main part of thesis. These are the electronic judicial record, electronic filing and electronic delivery. Author describes the conditions to implement these features, ascertains the current situation and identifies assets and imperfections of actual solution. Main goal of this thesis is to provide reader with the view of the electronification of the judiciary in the Czech Republic and sum up the most importatnt parts of electonical civil judicial proceeding.

The work examines legislative requirements for records management systems and databoxes system. It suggests processes and records office system as a universal solution suitable for deployment in a wide range of organizations.

The diploma thesis deals with the issue of audit of financial statements from the perspective of the auditor and documentation of his procedures. The first part defines the basic concepts in this area and further describes the audit procedures and proposes an effective system of audit procedures applied to selected companies.

Chapter -I Introduction Salmonella is a pathogen well-known for its ability to infect a wide variety of hosts and causes disease ranging from mild gastroenteritis to typhoid fever. During infection, it is exposed to a myriad of conditions; from the aquatic environment, the gut lumen to the phagolysosome. The success of Salmonella as a pathogen lies in its ability to sense each of these environments and adapt itself for survival and proliferation accordingly. This is done mainly via the action of specific two-component systems (TCSs) which sense cues specific to each of these niches and trigger the appropriate transcriptional reprogramming. This reprogramming is best studied for the genes directly known to be involved in virulence. In the case of Salmonella, most of these genes are a part of specific clusters, acquired through horizontal gene transfer, known as Salmonella Pathogenicity Islands (SPIs). Of the various SPIs, the two most important are SPI-1 and SPI-2. SPI-1 is classically involved in orchestrating bacterial invasion of non-phagocytic cells in the gut, allowing the pathogen to invade the host. Furthermore, its role is well characterized in the classic inflammation associated with gastroenteritis. On the other hand, SPI-2 is specialized for survival within the harsh intracellular environment of host cells such as macrophages and epithelial cells. Other important virulence determinants include motility, chemotaxis as well as adhesins. The transcription of these virulence genes is under tight regulation and responsive to environmental conditions. Many small molecules such as short chain fatty acids, pp(p)Gpp, bile and acyl homoserine lactones among others are known to be potent regulators of virulence in Salmonella. Furthermore, the metabolic products of the normal flora in the gut also affect its virulence. Thus the metabolic status, of both the host as well as the pathogen, plays an important role in determining the outcome of the infection. Many metabolic enzymes and their products are now known to directly or indirectly affect virulence gene expression. In this study, we explore one such class of metabolic enzymes viz amino acid racemases. They catalyze the chiral conversion of L-amino acids to D-amino acids and vice versa. We have studied the biochemical properties of two such non-canonical racemases as well as their role in bacterial survival and pathogenesis. Chapter-II Identification and characterization of putative aspartate racemases in Salmonella Amino acid racemases, such as alanine and glutamate racemases, are ubiquitously found in all bacteria and they play an essential role in cell wall biosynthesis. Recently it has been found, that bacteria possess other amino acid racemases which produce non-canonical D-amino acids. These D-amino acids, upon secretion, further orchestrate various phenotypes such as cell wall remodeling and biofilm dispersal. In this study, we have explored the ability of Salmonella to produce such non-canonical D-amino acids. The genome of S. Typhimurium possesses genes encoding two putative aspartate racemases; ygeA and aspR. These genes were maximally expressed in mid-log phase of bacterial growth and their corresponding proteins ar localized in the outer membrane of the bacterium. The biochemical characterization of the proteins YgeA and AspR revealed that only the latter is catalytically active under in vitro conditions. AspR could catalyze the conversion of L-Aspartate to D-Aspartate and vice versa, however was unable to use any other amino acid as its substrate. With atleast one of the racemases showing catalytic activity, the profiling of the secreted D-amino acids in Salmonella conditioned medium was undertaken using LC-MS. It was observed that the bacterium actively secreted specific D-amino acids such as D-Ala and D-Met into the culture medium in a growth-phase dependent manner. Furthermore, analysis of the secreted D-amino acid profile of the strains lacking either one or both the racemases revealed that atleast a subset of the secreted D-amino acids were dependent on the activity of YgeA and AspR. Thus, D-amino acids secreted by S. Typhimurium might represent a novel class of signaling molecules. Chapter – III Role of aspartate racemases in growth and survival of S. Typhimurium In order to understand the role of ygeA and aspR in vivo, we created knockouts of these genes (both single as well as double knockout) in S. Typhimurium using λ Red recombinase strategy. These knockouts were then assessed for their growth and morphology. The aspartate racemase knockouts behave similar to the wild type during growth in LB as well as M9 minimal medium. While their gross morphology remained the same as the wild type, the size distribution of the racemase knockouts was slightly different in the stationary phase. Unlike the wild type bacteria, the mutants did not exhibit the characteristic reduction in cell size upon entry into stationary phase. In addition, the survival of the mutants in the presence of cell wall damaging agents such as bile and Triton-X 100 was compromised as compared to the wild type. This can be ascribed to changes in the cell wall of the bacterium, wherein the mutants accumulated peptidoglycan in the stationary phase of growth. This suggests that aspartate racemases might have an effect on cell wall biosynthesis in Salmonella in the stationary phase. Another important strategy employed by bacteria to survive in stress conditions is biofilm formation. It was seen that the mutants were compromised in their ability to form a biofilm at the liquid-air interface in vitro. This defect is due to a transcriptional downregulation of the genes required for biofilm formation. These results demonstrate that, contrary to the established inhibitory effects of D-amino acids on biofilms of various bacteria, the aspartate racemases appear to act as positive regulators of biofilm formation in Salmonella. Chapter – IV Involvement of aspartate racemases in the regulation of Salmonella pathogenesis Salmonella’s success as a pathogen can be broadly assessed by its ability to invade and replicate within two major cell types: epithelial cells and macrophage-like cells. We have studied the fate of the aspartate racemase knockout strains in both these cell types. While the mutants replicate as well as the wild type in macrophage cell lines, their ability to invade epithelial cell lines is highly compromised. This defect can be ascribed to the downregulation of the Salmonella Pathogenicity Island-1 (SPI-1) in the racemase knockouts at the transcriptional level. One of the major pathways that regulate SPI-1 activation is the flagellar pathway. It was observed that in addition to SPI-1, the motility of the racemase mutants was also highly compromised. The mutants did not possess any flagella and showed a high transcriptional downregulation of all the three classes of flagellar genes. Transcriptome analysis revealed a global reprogramming in the aspartate racemase mutants, resulting in the differential regulation of motility, adhesion, amino acid transport, cell wall biosynthesis and other pathways. Of the genes upregulated in the knockouts, FimZ is known for its negative effect on motility and might be responsible for the observed downregulation of the flagellar regulon. This suggests that ygeA and aspR might be repressors of fimbrial gene expression. In totality, the racemases affected the pathogenesis of Salmonella, where the double knockout was severely compromised in the colitis model of infection. Overall the study is the first to identify secretion of non-canonical D-amino acids by Salmonella and suggests that YgeA and AspR might be the source of the same. This is supported in part by in vitro studies with the purified proteins. Studies in vivo further highlight the possible substrates that might be utilized by these enzymes. Physiologically, the aspartate racemases appear to regulate cell wall remodeling and biofilm formation. In contrast to the established literature, aspartate racemases (and their possible D-amino acid products) seem to be essential for formation of biofilms and regulate this phenotype at the transcriptional level. Furthermore, our studies put forth aspartate racemases as novel positive regulators of Flagella and SPI-1, affecting the success of Salmonella in the colitis model of infection in mice. Transcriptome analysis hints at the pleiotropic effects of aspartate racemases in Salmonella, bringing forth hitherto unexplored roles for this class of enzymes in the biology of this pathogen.