L’optimisation des systèmes de production d’énergie par combustion requiert une connaissance précise de la cinétique de combustion. Cependant, la majorité des systèmes de production d’énergie par combustion fonctionnent à haute pression et il est reconnu que la pression a une influence sur la cinétique de combustion. En laboratoire, l’analyse de la structure de flamme laminaire se présente comme un outil puissant pour étudier la chimie de la combustion. A ce jour, la plupart des travaux menés ont été réalisés à des pressions inférieures ou égales à la pression atmosphérique. Au cours de cette thèse, un dispositif expérimental pour l’analyse de structure de flammes laminaires, à contre-courants et à haute pression a été mis en place. Il permet de stabiliser des flammes de CH4/air et CH4/CO2/air jusqu’à 0,7 MPa et l’étude de leur structure par diagnostics laser. Les profils de concentration de OH dans les flammes CH4/air et CH4/CO2/air à différentes richesses (=0,7-1,2) et différentes pressions (P=0,1-0,7 MPa) ont été mesurés par Fluorescence Induite par Laser et calibrés en concentration par absorption laser. Pour cela, la longueur du milieu absorbant a été déterminée par Fluorescence Induite par Plan Laser (PLIF). Une attention particulière a été portée aux corrections du signal de fluorescence prenant en compte l’élargissement de raie et le taux de collisions, qui augmentent avec la pression. Les profils expérimentaux obtenus ont été comparés à la modélisation à l’aide du code de calcul OPPDIF et des mécanismes cinétiques GRI-Mech3.0 et GDFKin®3.0. En parallèle, une analyse spectroscopique des flammes de CH4/air à haute pression a été entreprise. / The optimisation of practical combustion devices requires a detailed knowledge of the combustion kinetic. However, most practical combustion systems operate at high pressure and it is known that pressure has an influence on combustion kinetics. In laboratory, the analysis of laminar flame structure is a powerful tool for studying combustion chemistry. However, most of studies have been realised at pressures under or equal to atmospheric pressure. During this thesis, an experimental device has been implemented for the study of the structure of high pressure counterflow flames. It allows the stabilisation and the study of CH4/air and CH4/CO2/air flame structure through laser diagnostics until 0.7 MPa. CH4/air and CH4/CO2/air flames have been studied for a various range of stoichiometry (equivalence ratios from 0.7 to 1.2) and pressures (0.1 MPa to 0.7 MPa). Experimental OH concentration profiles have been measured by Laser Induced Fluorescence and calibrated by laser absorption. To do this, absorption path length has been determined by Planar Laser Induced Fluorescence (PLIF). Great care has been attached to the determination of the fluorescence signal by taking into account the line broadening and de-excitation by quenching which both arise at high pressure. Experimental data were compared with modeling results obtained through the OPPDIF calculation code with GRI-Mech3.0 and GDFKin®3.0 kinetic mechanisms. In parallel, a spectroscopic analysis of the CH4/air flames has been undertaken.

This diploma thesis deals with practical measurement and diagnostics on chosen Hyundai Santa Fe vehicle and on the training panel. The thesis is divided into two parts. The first part is to familiarize the reader with the fuel system of the diesel engine with the common-rail pressure magazine, with the concept of serial and parallel diagnostics. In the second part, the diplomat performs serial and parallel diagnostics of the diesel engine fuel system on the vehicle and on the training panel. The diplomant will further describe the measured data and evaluate the differences in the measurements.

Le soleil est une étoile active, et les éruptions solaires sont une des manifestations de cette activité. Il est admis que l'énergie disponible pour les éruptions solaires a une origine magnétique, et est transmise au milieu lors de phénomènes de reconnexion magnétique dans la couronne. Une partie de cette énergie permet d'accélérer les particules du milieu (électrons et ions). Cependant, les détails concernant les conditions dans lesquelles les particules sont accélérées et se propagent des régions d'accélération aux sites d'interaction lors des éruptions solaires ne sont pas encore tous compris.Plusieurs modèles d'accélération de particules ont été développés dans le cadre de l'étude des éruptions solaires. Dans certains modèles, les particules sont accélérées par un champ électrique généré au niveau de couches de courants électriques, qui peuvent être fragmentées, et qui sont préférentiellement localisées au niveau de surfaces quasi-séparatrices. Afin d'étudier le lien entre l'accélération de particules et le champ électrique direct produit au niveau de couches de courants, nous avons recherché s'il y avait des corrélations entre les sites d'émission des particules énergétiques et les courants électriques mesurés au niveau de la photosphère. Les observations X (dur) représentent les diagnostics les plus directs des électrons énergétiques produits pendant les éruptions solaires (rayonnement de freinage des électrons dans l'atmosphère solaire) et nous avons donc utilisé les observations X du satellite RHESSI (Reuven Ramaty High Energy Solar Spectrometric Imager) afin de produire des images et des spectres du rayonnement X dur des électrons énergétiques. Afin de caractériser les courants électriques dans la région éruptive, nous avons utilisé les données spectropolarimétriques de l'instrument HMI (Helioseismic and Magnetic Imager) du satellite SDO (Solar Dynamic Observatory) et nous avons calculé les densités de courants verticales photosphériques à partir du champ magnétique vectoriel reconstruit. Une corrélation entre les émissions X coronales (dues aux particules énergétiques proches du site d'accélération) et les rubans de forte densité de courants photosphériques (traces des couches de courants coronales) a été mise en évidence pour les cinq éruptions de classe X étudiées. De plus, grâce à la cadenc / The Sun is an active star and one manifestation of its activity is the production of solar flares. It is currently admitted that solar flares are caused by the release of magnetic energy during the process of magnetic reconnection in the solar upper atmosphere, the solar corona. During these flares, a large fraction of the magnetic energy is transferred to the acceleration of particles (electrons and ions). However, the details of particle acceleration during flares are still not completely understood.Several scenarios and models have been developed to explain particle acceleration. In some of them, electric fields, produced at the location of current sheets, which can be fragmented or collapsing, and which are preferentially located on quasi-separatrix layers (QSLs), are accelerating particles. To investigate a possible link between energetic particles and direct electric fields produced at current sheet locations, we looked for a correlation between X-ray emission from energetic electrons and electric currents which can be measured at the photospheric level. We used the Reuven Ramaty High Energy Solar Spectrometric Imager (RHESSI) data to produce spectra and images of the X-ray emissions during GOES X-class flares, and spectropolarimetric data from the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO) to calculate the vertical current densities from the reconstructed 3D vector magnetic field. A correlation between the coronal X-ray emissions (tracing the energetic electrons near the acceleration site) and the strong current ribbons at the photospheric level (tracing the coronal current sheet) was found in the five studied X-class flares. Moreover, thanks to the 12-minute time cadence of SDO/HMI, we could study for the first time the time evolution of electric currents: in several flares, a change in the current intensity, occurring during the flare peak, was found to be spatially correlated with X-ray emission sites. These observations enlighten a common evolution of both electric currents and X-ray emissions during the

Un grand nombre d’applications de plasmas à pression atmosphérique sont en développement. Une obtention de plasma à haute réactivité chimique pour un faible coût énergétique est possible par l’utilisation de décharges nanosecondes répétitivement pulsées (DNRP).Cette recherche concerne plus particulièrement l’effet des NRPD en combustion assistée par plasma. Cette dernière permet l’utilisation de flammes pauvres, qui produisent moins de NOx et qui sont par conséquent moins polluantes.Pour comprendre les phénomènes physico-chimiques qui régissent les NRPD, différents diagnostiques optiques et mesures électriques ont étaient mis en place.L’efficacité de la combustion est très sensible à l’oxygène atomique (O). Nous avons présumé dans nos travaux que la production de cette oxygène ce faisant via un mécanisme a deux étapes où l’azote de l’air produis par impact électronique de l’azote excité aux états (A,B,C), qui réagis ensuite avec l’oxygène moléculaire donnant de l’oxygène atomique.Les densités d’états excités N2(B) et N2(C) on été déterminées par spectroscopie d’émission. L’état N2(A) est lui mesure par spectroscopie d’absorption en cavité résonnante. L’évolution de la concentration de l’oxygène atomique est déterminée par TALIF et on a noté jusqu'à 50% de dissociation de l’oxygène moléculaire en oxygène atomique. Des mesures résolues spatialement et temporellement ont été effectuées. L’élévation de la température du gaz dans la décharge a été établie. Des mesures électrique de tension et de courant ont permis l’estimation de l’énergie déposée par pulse.En résume ses mesures nous ont permis de mieux comprendre et de caractériser une DNRP dans l’air. Le fait que les temps de décroissance et les valeurs de l’évolution des concentrations des états excités de l’azote coïncident avec ceux de la production de l’oxygène atomique et que le gaz voit sa température s’élever de quelques centaines de degrés tendent à valider le mécanisme à deux étapes proposé. / In the last decade, nanosecond repetitively pulsed discharges (NRPD) had became very popular, because they allow to produce high electron densities and active species for an energy efficiency unequalled in air at atmospheric pressure.This thesis targets more particularly the effect of the NRP discharges in plasma-assisted combustion. NRP discharges can stabilize low temperature flames, which produce fewer NOx and are consequently less polluting. Few studies have investigated the mechanism of action of the plasma on flames.We have studied the kinetic mechanism of the atomic oxygen production, known as “two-step” or “ultrafast” mechanism. Where the nitrogen excited states (states A3Su,+, B3Pg, C3Pu) produced by electron impact during the 10ns-pulse dissociate oxygen with a heat release.To this end, various optical diagnostic techniques and electrical measurements, with time and space resolution of nanoseconds and hundreds of micrometers, have been set up.Densities of the excited states N2(B) and N2(C) have been determined by quantitative emission spectroscopy. The density of N2(A) state, was measured by a sensitive detection technique, Cavity-Ring Down Spectroscopy (CRDS). Finally the time evolution of the density of atomic oxygen was determined by Two-Photon Absorption Laser Induced Fluorescence or TALIF. In addition, an increase of the gas temperature related to the two-step mechanism was determined by emission spectroscopy.The work of this thesis represents the first experimental confirmation of the two-step mechanism suggested in the literature. At atmospheric pressure, this mechanism is found to dissociate up to 50 % of molecular oxygen and heats the gas by about 1000 K.As a summary, the work of this thesis allowed characterizing and better understanding nanosecond repetitively pulsed discharges in the air at atmospheric pressure and determining the production on the key active species, atomic oxygen.

Doctor of Philosophy / Department of Chemistry / Stefan Bossmann / Numerous Proteases are implicated in cancer initiation, survival, and progression. Therefore, it is important to diagnose the levels of protease expression by tumors and surrounding tissues, which are reflected in blood and tissue samples. Nanoplatforms for Cathepsin(CTS) B and L, matrix metalloproteinases(MMP) 1, 2, 3, 7, 9, 13 and urokinase plasminogen activator(uPA) detection have been synthesized. Nanoplatforms feature a central dopamine-coated core/shell Fe/Fe₃O₄ nanoparticle. Cyanine 5.5 is permanently tethered to the dopamine ligands via amide bonds. Tetrakis(4-carboxy-phenyl)porphyrin (TCPP) is co-tethered to Fe/Fe₃O₄/dopamine by means of protease consensus sequences. In the presence of a relevant protease sequence, it is cleaved, releasing TCPP from the nanoplatform. In contrast, Cy 5.5 will remain permanently tethered to the nanoparticle. Therefore, an extensive increase of emission intensity of the fluorescence signal from TCPP is observed. This permits the detection of the activity of proteases at femtomolar levels in biospecimens by fluorescence spectroscopy. 46 breast cancer and 20 healthy human blood serum samples were analyzed. Based on the expression pattern of analyzed enzymes, human breast cancer can be detected at stage I. By monitoring CTS B and L stage 0 detection may be achieved. This study demonstrates the feasibility of minimally invasive successful early cancer diagnosis. Immunosuppression is one of the hallmarks of aggressive cancers. Arginase is overexpressed in cancer patients, resulting in systemic immunosuppression. Two nanoplatforms for arginase detection have been synthesized. Both feature a central dopamine-coated core/shell Fe/Fe₃O₄ nanoparticle to which cyanine 7.0 or cyanine 7.5 is tethered via amide bonds. In both nanoplatforms, cyanine 5.5 is linked to the N-terminal of the peptide sequence GRRRRRRRG. Arginine (R) reacts to ornithine (O) in the presence of arginase. According to our results obtained from fluorescence spectroscopy, the oligopeptides GRRRRRRRG and GOOOOOOOG differ in their chain dynamics. In the presence of arginase, and dependent on arginase activity, fluorescence increase of both nanoplatforms is observed, which is an indication that proton-transfer quenching decreases when arginine gets converted to ornithine. The novel assays permit the detection of active arginase within an hour. Additionally, Förster Resonance Energy Transfer (FRET) is observed in nanoplatforms featuring cy 5.5/7.0 pairs, resulting in picomolar detection limits. This is the first example of a “post-translational” enzyme sensor, in which the tether is subjected to chemical transformations of the aminoacid side chains and not cleaved by an enzyme, resulting in the modified mobility of the tether. The nanoplatforms do not show a fluorescence increase when incubated with NO-reductase, an enzyme indicative of immunoactivation, which also uses arginase as substrate. Copper dependent inhibitory activity of 10000 compound library has been studied against of Staphylococcus aureus. 53 copper- dependent hit molecules were recognized featuring extended thiourea core structure with NNSN motif. NMR titrations, UV/Vis studies have been performed for characterization of metal complexation and structure modeling. Chemoinformatic meta-analysis of the ChEMBL chemical database confirmed the NNSNs as an unrecognized staphylococcal inhibitor, in spite of other compound groups in chemical screening libraries. This will lead to the development of novel class of antibacterial agents against Staphylococcus aureus.

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This diploma work is targeting fault diagnostics of electronic systems and engines used in automobiles. Results and methods used to diagnose faults are analyzed within the work, using standard diagnostic methods and devices, results of which were captured measuring with multi-channel oscilloscope. Furthermore, suggestions of using methods optimized for cost and time difficulty factors are made.

The thesis deals with possibilities of application of VAG-COM PROFI diagnostic kit in forensic engineering. After defining a theoretical basis, according to possibilities of evaluation of technical condition of a vehicle, the thesis is focused on applying diagnostic methods using above mentioned diagnostic kit. With respect to opportunities of identification of driving parameters, possibility of acceleration measurement and estimation of engine power are introduced. Describing of methodology and making the final statement are contained in the thesis as a part of every single measurement.

The outbreak of infectious diseases across the world results in huge disasters for public health. Rapid and effective diagnostic methods are crucial for disease identification and transmission control. Since first identified in late 2019, the pandemic of COVID-19 caused by the SARS-CoV-2 virus resulted in unprecedented catastrophe globally. To control the further spread of COVID-19, there is an urgent need for rapid, accurate, cost-effective, and efficient diagnostics. Recently, many CRISPR-based diagnostics have been developed by coupling isothermal amplification methods with Cas proteinmediated nucleic acid detection. Compared with conventional methods like RT-qPCR, CRISPR-based assays are more cost-effective and efficient without sacrificing sensitivity and specificity. Here, I developed a Cas13-based assay for SARS-CoV-2 detection with a novel compact Cas13b protein. In this assay, the Cas13 detection is combined with RT-LAMP, achieving the detection of viral RNA as low as 4 copies/μl. By utilizing a simple LED-based visualizer (P51™) instead of a plate reader, the detection result can be visualized directly without using sophisticated instruments. The compact Cas13b-mediated viral detection together with P51™-based visualization enable rapid, sensitive, and portable diagnostics for SARS-CoV-2, showing great potential in application to point-of-care testing.