Title: Computational study of probe diagnostics in high-temperature plasma Author: Jan Lachnitt Department: Department of Surface and Plasma Science Supervisor: prof. RNDr. Rudolf Hrach, DrSc., Department of Surface and Plasma Science Abstract: This work is concerned to the particle computer modelling of the interaction of plasma, especially edge plasma, with immersed solids, especially probes. First, the speed and accuracy of several algorithms of the electrostatic force calculation were compared. One of the algorithms has been newly proposed. Then, a two-dimensional model of the interaction of collision-less plasma with a probe was created. This model has been applied to experimental data from CASTOR tokamak. The crucial point of this work is the creation of a fully three-dimensional particle model. This model has been tested for accuracy and speed and has been parallelized for higher efficiency. Keywords: plasma, probe diagnostics, computational physics, particle modelling

Mammalian fertilization is a sequence of unique and fascinating events, during which seminal proteins are of crucial role. In case of bull (Bos taurus), proteins of seminal plasma (BSP), especially its major component PDC-109, are known to be in aggregated forms, but little is known about mechanism of forming aggregates and their biological function. In present thesis we discovered some interesting properties of PDC-109 and BSP proteins. We found that concentration of these proteins influences their aggregation state significantly, which can be of great biological importance. Separation of seminal proteins by size exclusion chromatography revealed three main fractions denoted I, II and III, with apparent molecular weights of Mr > 150 000, Mr = 30 000 and Mr = 13 000, respectively. In case of PDC-109, molecular weights of theese fractions were retained even after purification procedure, which implies very stable interactions in forming of aggregates. In addition, there was a difference in distribution of PDC-109 glycoforms among fractions, which can be related to the fact, that theese fractions have different sperm membrane binding patterns as we determined by fluorescence microscopy. However, further experiments are needed for better understanding this issue.

The dissertation thesis deals with the problems of the use of plasma technologies in agriculture for the purpose of improving the quality of feedstuffs for agricultural animals. The attention is focused above all on the use of low-temperature gliding arc plasma discharge generated by the atmospheric pressure for the elimination of model fungal pathogens (T. virens) and for the testing of the possibility of the use of plasma for the decreasing of mycotoxin load (DON and D3G). The professional orientation of the dissertation thesis is strongly interdisciplinary with the overlap to the area of the physics of plasma, microbiology, zootechnics and the proposal and construction of technical facilities. With that corresponds also the division of thesis into individual chapters. In the research part, there is a summary of actual pieces of knowledge from the area of fungal microorganisms and mycotoxins produced by these with the view on their presence in feedstuffs. There follows a research of pieces of knowledge of low-temperature plasma and its applications in the food industry and feeding. In the chapter Material and Methodology, the applicated methods of work, employed instruments and biological material are described. The resulting part is, for its clear arrangement, divided into five subchapters ? stating of selected parameters of plasma device, influence of plasma on nutritional parameters, influence of plasma on the model fungus Trichoderma virens and possibilities of the use of plasma discharge for the decreasing of concentration of mycotoxins in feedstuffs. The final part is dedicated to the description of system which enables the treatment of samples in continuous regime. The treatment of mycelial discs by plasma discharge lead to the decrease of germination capacity of spores of fungi, while there was experimentally proven the synergic effect of the influence of individual mechanisms by which the plasma interacts with the surface of biological material. At the same time, there was not observed a more significant change in the composition of feedstuffs, more significant is only the change of humidity of sample. In the laboratory conditions, the decreasing of concentration of mycotoxins spread on laboratory glass was proven. At the samples of feedstuffs contaminated by natural way, it was not successful to reliably provedecreasing of concentration of mycotoxins in a sample as a result of plasma activity.

The dissertation thesis deals with the use of low-temperature plasma and biological treatment of winter rape seed and spring barley as an alternative to chemical dressing in relation to the Decree on Integrated Pest Management 205/2012 Coll. The seed treatment technology is conceived as a two-phase process, where a lowtemperature plasma discharge of the Gliding Arc type ignited in the air at atmospheric pressure is used in the first step and a biological preparation containing spores of Trichoderma virens is applied to the treated seed as the second step. The plasma discharge treatment allows to increase the wettability of the seed surface, which improves the adhesion of the biological preparation in the second treatment step. Plasma also enables to activate selected processes taking place in seeds, which support their germination and subsequent growth. The content of the dissertation is divided into four sub-units which are mutually related: 1. determination of plasma discharge parameters for subsequent applications in the proposed technology, 2. carrying out laboratory experiments to assess the effect of plasma on seed, 3. carrying out field experiments to compare crop yields for different seed treatment options, 4. proposal for a regulation for seed treatment in a continuous mode by plasma discharge followed by application of the preparation and production of a functional sample. The work is markedly interdisciplinary and intervenes in the field of plasma physics, chemistry, plant production and construction of technical equipment. From the results achieved we can give a short summary: 1. Plasma discharge treatment of winter rape and barley seeds results in increased surface wettability. 2. No difference in the absorption of plasma treated and untreated seeds was observed during the experiments. 3. Developed dual seed treatment technology has the potential to increase yield. The dissertation thesis was realized within the project TA04021252 ? "Development of equipment for physical treatment of seeds and malt using low-temperature plasma."

The dissertation was implemented in-collaboration with international research centers in Europe, who participates in the development of new century thermonuclear reactors process. The existence of more than one plasma facing material at the ITER divertor target (CFC and W) can affect substantially the fuel retention properties of W by formation of deposited hydrocarbon layers and carbides and could lead to significant changes of the mixed-material properties with respect to that of the pure W material. The task of this work is to understand these effects by means of dedicated experimental studies to determine the influence of the various physics processes in the final erosion/redeposition pattern. The goal of the work is the fabrication of W films to be used in plasma – facing components in fusion devices, and the understanding of the mechanism of physical phenomena initiating modification of mechanical properties of W – based thin films on stainless steel substrates under Ar ion irradiation and under high-flux, low-energy H+ ions irradiation in the range of temperatures. During this work there were fabricated nanocrystalline W coatings on carbon based materials (including cfcs) using magnetron sputtering technique. Main parameters: area of deposits – 20 x 17 cm, thickness homogeneity – better than 20%, coating thickness – 3-6 µm. The microstructure of w coatings was densified by deposition under continuous ion bombardment and optimization of grain size and texture to improve... [to full text] / Tiriamasis darbas nagrinėja fundamentalias plazmos sąveikos su termobranduolinio reaktoriaus sienelėmis problemas. Jis atliktas bendradarbiaujant su tarptautiniais tyrimų centrais Europoje, dalyvaujančiais kuriant naujos kartos termobranduolinį reaktorių. W dangos, gautos magnetroniniu garinimo būdu, buvo paveiktos argono jonų su anglies priemaišomis spinduliuote esant skirtingiems slėgiams eksperimentiniame įrenginyje. Pagrindinis dėmesys sutelktas į teigiamų jonizuotų dalelių ir plazmos sąveiką su volframo danga anglies adsorbcijos metu ir jų poveikį volframo dangos savybėms. Darbe ištirtos ir išaiškintos sąlygos, prie kurių anglis, readsorbuota iš plazmos, efektyviai pernešama į W tūrį. Darbe parodyta, kad, vykstant vienalaikei C adsorbcijai ir joninei spinduliuotei, anglis efektyviai pernešama nuo paviršiaus į tūrį, kai W paviršius tik dalinai padengtas adsorbuota anglimi. Kai W paviršius padengtas ištisine C plėvele, anglies pernešimas nuo paviršiaus į tūrį yra blokuojamas. Gautų spinduliuote paveiktų dangų savybės buvo nagrinėjamos sekančiomis technologijomis: paviršiaus topografinė analizė atlikta naudojant skenuojantį elektroninį mikroskopą, atominės jėgos mikroskopą, dangų struktūra tirta su rentgeno spindulių difraktometru, dangų profilio analizė atlikta rusenančio išlydžio optinė spektroskopija. Panaudoti analizės metodai sudarė galimybes tirti dangų elementinę sudėtį, mikrostruktūrą, paviršiaus reljefą ir atlikti elementinės sudėties profiliavimą nuo paviršiaus... [toliau žr. visą tekstą]

Šiame darbe, panaudojant jonines-plazmines technologijas, sintezuotos Mg, MgH2, Mg-Al ir Mg(AlH4)2 plonos nanokristalinės dangos. Ištirta jų struktūros, paviršiaus morfologijos ir sudėties priklausomybė nuo nusodinimo ir hidrinimo plazmoje technologinių parametrų. Darbe panaudoti plėvelių formavimo metodai: (i) magnetroninis-joninis garinimas Ar dujų aplinkoje; (ii) plonų dangų prisotinimas vandeniliu, panaudojant vandenilio jonų implantacijos iš plazmos technologijas. Šio darbo originalumas susijęs su nepusiausvyrinių plazminių technologijų panaudojimu nanokristalinių medžiagų hidrinimui. Pirmą kartą atlikta metalų hidridų sintezė ir ištirta vandenilio kaupimosi kinetika nanostruktūrinėse medžiagose panaudojant plazminės vandenilio implantacijos technologiją. Gauti rezultatai patvirtina joninių-plazminių technologijų pranašumus, iš kurių svarbiausias - formuojamų plėvelių mikrostruktūros valdymas nanometriniame lygyje. Tyrimo metu, panaudojant vandenilio jonų implantaciją į Mg-Al dangas, pirmą kartą susintezuotas Mg(AlH4)2 hidridas. 5 storio Mg dangų transformacija į MgH2, hidrinimo procesą atliekant vandenilio plazmoje, įvyksta esant 400 K temperatūrai. Eksperimentiniai rezultatai atskleidė, kad Ti priemaišomis legiruotose Mg dangose paspartėja hidridų formavimosi kinetika, o vandenilio desorbcijos temperatūra sumažėja 60-80 K. Vandenilio desorbcijos kinetika Ti priemaišomis legiruotose Mg-Al dangose taip pat yra spartesnė, o jų desorbcijos temperatūra sumažėja 65 K... [toliau žr. visą tekstą] / In the present work Mg and MgAl thin films were fabricated using physical vapour deposition (PVD) technologies as non-traditional and new nanotechnology methods for designing high performance hydrogen storage materials. The physical vapour deposition technologies allow the formation of metastable metal, alloy and chemical compounds with strictly controlled composition, microstructure and stoichiometry at low temperatures. The synthesis of MgH2, MgAl and Mg(AlH4)2 films has been conducted in two steps: (i) fabrication of thin films employing magnetron sputtering in Ar gas, and (ii) hydrogenation of thin films employing plasma immersion ion implantation technologies. For the first time, chemical compound Mg(AlH4)2 has been synthesized using the deposition of Mg and Al atoms from gas phase in hydrogen plasma (reactive deposition with simultaneously hydrogen implantation). The transformation of Mg thin film to MgH2 takes place at 400 K temperature during hydrogenation in hydrogen plasma. Experimental results showed that hydriding kinetics of Ti-doped Mg film increases and desorption temperature decreases by 60-80 K and the maximum H2-effusion from the Ti-undoped Mg-Al takes place at temperature 475 K, and for the Ti-doped Mg-Al film – at temperature 410 K; the release time of accommodated hydrogen is shorted for the Ti-doped Mg-Al film. The mathematical model of hydrogenation shows that during the process of material irradiation in plasma the concentration of incident ions in... [to full text]

Bakalauro darbą „Plazmoelektrolitinio proceso stabilumo sąlygų tyrimas“ sudaro įvadas, 3 skyriai, išvados, literatūros sąrašas, priedai ir 1 kompaktinis diskas. Darbo apimtis 39 puslapiai. Darbe pateikti 26 paveikslai, 1 lentelė. Įvade iškeliama darbo problema, pagrindinis tikslas ir uždaviniai. Pirmąjame skyriuje pateikiami pagrindiniai teoriniai teiginiai apie procesus sudarančius vandenilio plazminę elektrolizę: elektrolizę ir plazmą. Antrąjame skyriuje analizuojami ir aptariami moksliniai straipsniai, kuriuose kalbama apie atliktus vandenilio plazminės elektrolizės proceso tyrimus. Išryškinami tyrimai, kurie susiję su šio proceso stabilumo stebėjimais. Trečiajame skyriuje aptariami atlikto plazmoelektrolitinio proceso stabilumo sąlygų tyrimo rezultatai ir pateikiama jų analizė. / The Bachelor paper “The investigation of the stability conditions of plasma electrolysis process ” consists of introduction, three chapters, conclusions, literature source, additions and 1 CD. The volume of this work is 39 pages. There are 26 pictures and 1 table in this work. Work problem, objective and goals are provided in the introduction. The first chapter is provided main theoretical propositions about processes which take part in hydrogen‘s plasma electrolysis: electrolysis and plasma. Second chapter analyze and review scientific articles about hydrogen’s plasma electrolysis research. The paper underlines studies, related to mentioned process and it’s monitoring of stability. In the third chapter a reader will find the results and their analysis about stability conditions of plasma electrolysis process.

This thesis identifies the obstacles in efficient modelling of interaction of plasma and solid surfaces. It presents an enhanced method of solving the Poisson equation optimized to meet the requirements of the Particle-in-Cell modelling approach. A number of applications are discussed, including models of the plasma-facing wall of the nuclear fusion device, tokamak, and its interaction with particle fluxes driven by the intrinsic magnetic field. Another area of applications covers the modelling of plasma probes deployed to diagnose properties of plasma in various experiments. The thesis also includes the computer library code and instructions enabling a rapid use of the Poisson solver method in a third party computer code which implements the PIC approach in a compatible manner.

David PÍŠA Study of electromagnetic emissions recorded by the DEMETER satellite Abstract : This thesis presents results based on wave measurements performed by the DEMETER space- craft. This French spacecraft was operating between 2004 and 2010 at the altitude of ∼660 km. We focus on measurements of the electromagnetic waves and plasma density in the vicinity of imminent earthquakes. In the first part, we present a study of plasma density variations in the vicinity of a very powerful earthquake in Chile (Mw 8.8) which occurred on February 27, 2010. Data recorded before the main shock along orbits close to the future epicenter showed increasing plasma den- sities. A statistical analysis using 4 years of data to monitor density variations under similar conditions has been performed. This study shows that a large increase of the plasma density is very uncommon at this location. In the second part, a statistical study (∼6.5 years) of variations of VLF wave intensity is shown. We have analyzed all available data measured close (in time and space) to large earth- quakes (M≥5). Data related to more than 12000 earthquakes have been compared with an unperturbed background distribution. We confirm the previously reported results of a statis- tically significant decrease of the wave intensity at frequencies of about...

This work deals with the study of dissociation of iodine molecule for Chemical and Discharge Oxygen-Iodine Laser. Chemical way of HI dissociation and discharge way of dissociation of CH3I and CF3I molecules is examined. Main diagnostics method is absorption spectroscopy. Part of the work is also the modeling of system of chemical reactions. Last part of this work is dealing with the study of plasma generated by the radiofrequency generator in the hollow cathode plasma jet system using argon or mixture of argon with iodine. Diagnostic method used is Langmuir probe.