The study of plasmas generated in pure nitrogen and their afterglows are a subject of many hundreds works bringing a lot of information about the kinetic processes and energy transfer reactions. The effect of nitrogen pink afterglow has a specific position among the other kinds of discharges and post-discharges. The post-discharge, and especially the pink afterglow, is extremely sensitive to the presence of various impurities and experimental conditions (total gas pressure in a discharge tube, temperature, etc.) because of their significant influence on all kinetic processes. That is the reason, why it is so important to study this processes. The DC flowing afterglow (generated using the hollow molybdenum electrodes in the distance of 12 cm, power ± 290 W) was used for the experimental part of this work. The discharge was created in Pyrex discharge tube at different concentration ratio of nitrogen and argon. The total gas presure was in range from 500 Pa to 5000 Pa. The emission spectra of post-discharge were recorded by TRIAX 550 spectrometer with CCD detector in the range of 320-780 nm. The vibrational populations at individual vibrational levels were calculated using the emission bands of the first (N2 (B 3g) N2 (A 3u+)) and the second (N2 (C 3u) N2 (B 3g)) positive and the first negative (N2+ (B 2u+) N2+ (X 2g+) nitrogen spectral systems. The dependencies of intensity on decay time and relative vibrational populations on argon concentration and pressure were obtained. The pink afterglow was very sharp in pure nitrogen at low pressure. With the increasing total pressure it was shifted to the later decay times and it was visible for longer time, too. The same effect was observed with the increase of argon concentration in the gas mixture. At the highest argon concentrations, especially at lower pressure, the effect of pink afterglow dissapeared. The knowledge of these processes can give the solution of all kinetic reactions in plasma and this can be used in plasma chemistry and for development of new technologies. This will be a subject of further intensive studies.

The decaying plasma was studied by the optical emission spectroscopy. DC discharge created at 45 – 200 mA in Pyrex and Quartz tubes in flowing regime was used. The emission of three nitrogen spectral systems (1st and 2nd positive and 1st negative) were studied in time evolution for pressures of 500 – 5 000 Pa at two wall temperatures – ambient and liquid nitrogen (150 K inside the decaying plasma). Results showed that all three nitrogen systems (respectively N2(B, v), N2(C, v) and N2+(B, v) states as their origins) had their population maxima called pink-afterglow in the afterglow part. These maxima decreased with the increase of pressure for all systems, and moved to the later decay time. Maxima increased with discharge current (respectively power) and moved to shorter time. Populations at temperature of 150 K were measured due to the experimental arrangement from 17 ms, only, and thus pink aftergow maximum wasn’t observed (only at 5 000 Pa some maximum was recognized). Populations were smaller at 150 K that populations measured at laboratory temperature at the middle decay time (50-100 ms). At the late time, the populations were higher at lower temperature at lower pressure. Higher shifts (in intensity and decaytime) of pink afterglow maxima were observed in Quartz tube in comparison with their values in Pyrex tube. Besides the populations, rotational temperatures of selected bands of three observed spetral systems (for 1st negative 0-0 band, 1st positive 2-0 band and for 2nd positive 0-2 band) were measured. Rotational temperatures were monitored from presumption that this kind of temperature is equal to temperature of neutral gas (at local thermodynamic equilibrium). Results from 1st negative and 1st positive system showed strong decreasing of rotational temperatures up to about 10 ms at post-discharge begin, then temperatures were constant up to 20 ms of decay time and after that they grew up. Temperatures increased with the increase of current. The part with decreased temperature correlated with pink-afterglow part of post-discharge. Unfortunately, rotational temperatures of 2nd positive system had bad reproducibility and the time profile shape was opposite. Experimental results were compared with numerical kinetic model created by group of prof. Vasco Guerra at Instituto Supetior Técnico in Portugal. Several sets of conditions for simulation at 500 and 1 000 K in active discharge were applicable for the calculation corresponding to the experiment. Comparison of numerical simulation and experimental data done for N2(B) state demonstrated that maxima populations in pink afterglow are depended on the temperature difference between active discharge and post discharge. Maxima populations were supposed in pink afterglow disappeared if the same temperatures in active and post discharges were supposed. Temperature in active discharge is higher at higher apllied power, as it was showed from rotational temperatures observation. The results clearly showed that real temperature profile must be included into the kinetic model.

The aim of this master thesis is a study of nitrogen post-discharge by mercury vapours titration. The nitrogen post-discharge is investigated for many years theoretically as well as for a practical use. The object of this master thesis is a study of kinetic processes ongoing at titrations of mercury vapours during the nitrogen post-discharge at different pressures and applied powers. All experimental data were obtained from an optical emission spectroscopy of nitrogen post-discharge. DC discharge in flowing regime was chosen for measurements. The first part of experiments was carried out at the constant discharge current (100 mA), voltage (1300 V) and wall temperature (300 K). The total gas pressure was varied in range of 500-3000 Pa at nitrogen flow in range of 0.12-0.68 l/min. Nitrogen flow values were arranged to obtain constant nitrogen flow velocity for all gas pressures. The second set of experiments studied power dependencies. The current was varied in the range of 50-200 mA for constant voltage 1300 V. The total gas pressure in this case was 1000 Pa. Mercury vapours were introduced into the system by titration tube at different post-discharge time. The nitrogen pink afterglow effect was well visible at all experimental conditions. This effect corresponds to the maximum intensity of light emission, which expresses as considerable growth of characteristic pink radiation in the post-discharge time. Optical emission spectra of post-discharge were taken in the range of 320-780 nm. Besides three nitrogen spectral systems (first and second positive and first negative), the mercury line at 254 nm was recorded in the second order spectrum at 508 nm under these conditions if mercury was added. This spectral line is excited under post-discharge conditions by collisionally induced resonance energy transfer from nitrogen highly vibrationally excited ground state metastables and it opens an unique technique for their monitoring. The dependence of relative intensities on decay time for mercury spectral line and selected nitrogen spectral systems at different titration positions were measured. The relative intensities of nitrogen bands decrease with increasing of mercury line relative intensity for all total gas pressures. The pink afterglow phenomenon shifts to the later decay times with the increasing of total gas pressure. In the case of experiments at different power, it can be seen that with decreasing power mercury spectral line intensity decreases in post-discharge time. The first detailed tests of the unique detection for highly excited of nitrogen metastables were completed. However this master thesis is concentrated on the basic research which supports better indication of kinetic processes and reactions leading to transformation of excitation energy, this new knowledge should be applied in future also in technologies based on the long-lived metastable induced reactions.

There are few data on mortality after discharge with community-acquired pneumonia (CAP). Therefore, we evaluated risk factors for 30-day post-discharge mortality after CAP. We included all patients of the prospective multi-national CAPNETZ study between 2002 and 2018 with (1) hospitalized CAP, (2) survival until discharge, and (3) complete follow-up data. The study endpoint was death within 30 days after discharge. We evaluated risk factors including demographics, comorbidities, admission CAP severity, and laboratory values and treatment-related factors in uni- and multivariable analyses. A total of 126 (1.6%) of 7882 included patients died until day 30 after discharge, corresponding to 26% of all 476 deaths. After multivariable analysis, we identified 10 independent risk factors: higher age, lower BMI, presence of diabetes mellitus, chronic renal or chronic neurological disease (other than cerebrovascular diseases), low body temperature or higher thrombocytes on admission, extended length of hospitalization, oxygen therapy during hospitalization, and post-obstructive pneumonia. By addition these factors, we calculated a risk score with an AUC of 0.831 (95%CI 0.822–0.839, p < 0.001) for prediction of post-discharge mortality. Early post-discharge deaths account for ¼ of all CAP-associated deaths and are associated with patient- and CAP-severity-related risk factors. Additional studies are necessary to replicate our findings in independent cohorts. Study registration: NCT 02139163.

There are numerous threats to medication safety at care transitions, which are heightened for older people, because they live with multiple long-term conditions as well as polypharmacy, and have frequent hospital admissions. Whilst evidence of the severity and scale of these medicines-related problems exists, there is insufficient detail about the lived experience of post-discharge medicines management, in particular what helps or what hinders, and how better support could be enabled. This thesis, underpinned by the Medicines Research Council framework for complex intervention design, aimed to find acceptable intervention components, which would enhance patient experience. This research followed a sequential, mixed method design to: establish the evidence base through critical literature review, develop theory using an interview study grounded in behaviour change theory, and finally to model potential intervention components by expert consensus. Interviews revealed that there were gaps in current service provision, which impacted on participants’ knowledge of and capabilities with their medicines. Despite these challenges, some participants took actions to safeguard from problems after discharge. The literature review found that effective components of trialled interventions were self-management advice, post-discharge telephone follow up and medicines reconciliation. Further behaviour change techniques from the literature, alongside expert consensus and theory-driven analysis of interview findings resulted in final selection of eight potential components. Real-world implementation of these must be coupled with key changes to current healthcare practices and policy, including better engagement with patients and carers, as well as pro-active post-discharge follow-up. Future work must carefully explore how these components can be tested pragmatically.

Les travaux présentés dans ce mémoire portent sur l’étude des plasmas d’hélium générés par micro-ondes en cavité résonnante à la pression atmosphérique et sur leurs applications en traitement de surfaces. Tout d’abord, un état de l’art sur les plasmas micro-ondes à la pression atmosphérique et leurs applications est présenté. Ensuite, un modèle collisionnel-radiatif de la décharge et de la post-décharge d’hélium pur est établi. Les résultats du modèle sont comparés aux mesures expérimentales obtenues à 2500 K et un jeu de sections efficaces et de constantes cinétiques valables pour ces conditions est proposé. Expérimentalement, des analyses par spectroscopie d’émission et d’absorption sont employées. La température du gaz est déterminée par la méthode du spectre rotationnel synthétique en fonction de la puissance, de la concentration et de la nature des impuretés introduites dans l’hélium. Il s’avère que le volume du plasma est un paramètre déterminant sur la température du gaz. La concentration du métastable He(23S), en décharge continue et pulsée, est déterminée par absorption laser. En décharge continue, la concentration du métastable est divisée par trois avec 360 ppm d’impureté, la nature de l’impureté n’ayant pas d’importance. En revanche, en post-décharge la nature de l’impureté est déterminante. Les mesures réalisées indiquent que He+ et non He2+ serait l’ion majoritaire. Concernant les applications de ce type de plasma, nous avons travaillé en post-décharge uniquement. Nous avons démontré la faisabilité du procédé de dépôt de SiOx à partir d’hexaméthyldisiloxane. Nous avons aussi montré que la nitruration du titane à haute température était possible / The present work deals with the study of helium microwave plasmas at atmospheric pressure generated in a resonant cavity and their applications in surface treatment. First of all, a state of art of microwave atmospheric pressure plasmas and their applications is presented. Next, a collisional-radiative model for pure helium discharge and post-discharge is described. The results of the model are compared to experimental data obtained at 2500 K and a coherent set of cross-sections and rate constants is obtained for these conditions. Emission and absorption spectroscopy diagnostics are employed to characterize the helium plasma. The gas temperature is determined by the rotational synthetic spectra method. The evolution of the gas temperature, as a function of the input power, the concentration and the nature of impurities in helium, is measured. It turns out that the plasma volume plays a significant role on the gas temperature. The He(23S) concentration is determined by laser absorption in pulsed and continuous mode. In continuous mode, the metastable concentration is divided by 3 with 360 ppm of impurity, regardless of the nature of the impurity. Nevertheless, during the post-discharge, in pulsed mode, the nature of the impurity plays an important role. These measurements support the idea that He+ and not He2+ is the main ion. Concerning the applications, only post-discharges are utilized. We demonstrate that deposition of SiOx using hexamethyldisiloxane as precursor can be efficient. We show that titanium nitriding at high temperature is possible

Clean post-discharge nitrogen plasma and nitrogen plasma with different traces have been focus of scientists for more than 50 years and there were published many articles on theme active discharge, post-discharge, processes and reactions. It is possible to create kinetic models from all these information and then calculate concentrations of elements in atomic form. This diploma thesis is focused on measuring of concentration of atomic nitrogen for different conditions (decay time, pressure, admixture). The titration method by nitric oxide in post-discharge was used to determinate of concentration of atomic nitrogen. All experimental results were obtained by the optical emission spectroscopy. Optical emission spectra were taken in the range of 300-600 nm. DC discharge was created in a quartz tube in a flowing regime. The flowing regime was chosen for this experiment because of better time resolution of decay time, order in milliseconds. Decay time was in the range of 16 – 82 ms for individual experiments. Nitrogen flow was 400 mln/min. Nitrogen oxide flow was in the range of 0-10 mln/min and it was added at the selected post-discharge time. Trace of methane was 0,006 % of the whole volume. Total gas pressure was set on values from 500 to 4000 Pa. The output of discharge was set on constant value of current 150 mA and the output has changed according to the amount of pressure. Nitrogen first positive, second positive and first negative spectral systems, NO spectral system and NO2* spectral system were recognized in all measured spectra. Absolute concentration of atomic nitrogen was specified by the method of titration of NO. Traces of methane increase dissociation of molecular nitrogen and therefore increase the concentration of atomic nitrogen. This thesis brings new results into longtime research of moon Titan and new results into study of processes in nitrogen-methane plasma.

Presented thesis gives results obtained during the spectroscopic observations of post –discharges of the pure nitrogen plasma with small oxygen admixture and in the nitrogen – argon mixture and the effect of the pink afterglow in it. The DC discharge in the flowing regime has been used for the plasma generation. The decaying plasma was study by optical emission spectroscopy, mainly in the range of 300–800 nm. The first positive, second positive, first negative nitrogen spectral system and NO spectral systems were observed in measured spectra. The band head intensities of these bands have been studied in the dependencies on experimental conditions. Simultaneously, the relative vibrational populations on the given nitrogen states have been calculated. Two discharge tubes made from different materials (PYREX glass and QUARTZ glass) were used in the case of nitrogen plasma containing low oxygen traces (up to 0.2 %). These experiments have been carried out at two wall temperatures for the determination of the temperature effect on the post-discharge. The discharge tube around the observation point was kept at the ambient temperature (300 K) or it was cooled down to 77 K by liquid nitrogen vapor. The total gas pressure of 1 000 Pa and the discharge current of 200 mA were conserved for all these experiments. The relative populations of electronic states were calculated in the dependence on the post-discharge time. The dependencies on oxygen concentration were given, too. The results showed no simple dependence of vibrational populations on oxygen concentration. Generally, slight increase of neutral nitrogen states populations was observed with the increase of oxygen concentration. These observations were well visible due to the intensity of nitrogen pink afterglow effect that was well visible at all oxygen concentrations. The pink afterglow maximal intensity was reached at about 5–10 ms at the wall temperature of 300 K in the PYREX tube. The molecular ion emission was strongly quenched by the oxygen and as this was dominant process for the pink afterglow emission the pink afterglow effect disappears at oxygen concentration of about 2000 ppm. The temperature and wall material influences were observed, too. The post-discharge in nitrogen argon mixtures was studied only in the PYREX tube at the ambient wall temperature of 300 K. The power dissipated in an active discharge was constant of 290 kW. The experimental studies had two new parameters – total gas pressure (500 Pa – 5 000 Pa) and the argon concentrations that were varied in the range of 0–83 %. Also in this case the dependencies of relative intensities of the bands given above were obtained and further the relative populations of electronic states as a function of decay time, total gas pressure and on argon concentration were obtained. The pink afterglow effect was observed at all applied discharge powers and total gas pressures. At the highest argon concentrations, especially at lower pressure, the pink afterglow effect disappeared. The presented experimental work is one of the hugest sets of experiments in the nitrogen with oxygen traces and in nitrogen-argon mixtures. These data can be used as a very good fundament for the further studies using wide numeric modeling of the post-discharge kinetic processes.

Introduction Transition care clinics (TCCs) have proven to be effective in meeting the time-sensitive needs of patients in the post-discharge period and ensuring smooth transitions of patients from hospital to home. These clinics have led to lower readmissions, lower emergency department visits, cost savings, and lower rates of other adverse events following discharge. However, TCCs, including the East Tennessee State University Family Medicine (ETSU-FM) TCC have been facing high rates of patient no-shows. Aim The aim of this dissertation is to identify the different components and outcomes of TCC based on the literature. We further aim to analyze the TCC implementation process at the ETSU-FM clinic, identify gaps, and provide recommendations to address those gaps. Methods A scoping review was conducted using three databases (PubMed, Web of Science, and PsycINFO) searches while following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews Checklist to identify different components of TCCs and the associated outcomes. Additionally, a mixed-methods study was conducted using patients and providers from the ETSU-FM clinic to identify different factors associated with patients’ no-shows to scheduled TCC appointments. Results Eighteen studies were analyzed and TCC components and patients’ outcomes were assessed. Predischarge communication with patients and caregivers, early post-discharge contacts, etc. were identified as some of the effective components of TCC. Our review also highlighted that TCC resulted in lower readmissions, lower ED visits, and cost-effectiveness. For the mixed-methods study, we included 520 patients in our quantitative analysis and interviewed 10 providers for the qualitative analysis. Several patient-level and system-level factors were found to be associated with TCC no-shows. A few of the factors that were deemed modifiable by the clinic have been identified and recommendations provided accordingly. Conclusion TCCs play a vital role in ensuring smooth care transitions of patients following discharge. It is crucial to conduct context-level studies to identify factors that are associated with TCC no-shows and design interventions accordingly. Doing so could lead to pursuit of the triple aim of healthcare: improving patients’ experience of care, improving the health of populations, and reducing the per capita cost of health care.

Le recours au plasma pour stériliser des dispositifs médicaux (DM) est un domaine de recherche ne datant véritablement que de la fin des années 1990. Les plasmas permettent, dans les conditions adéquates, de réaliser la stérilisation à basse température (≤ 65°C), tel qu’exigé par la présence de polymères dans les DM et ce contrairement aux procédés par chaleur, et aussi de façon non toxique, contrairement aux procédés chimiques comme, par exemple, l’oxyde d’éthylène (OEt). Les laboratoires du Groupe de physique des plasmas à l’Université de Montréal travaillent à l’élaboration d’un stérilisateur consistant plus particulièrement à employer les effluents d’une décharge N2-%O2 basse pression (2-8 Torrs) en flux, formant ce que l’on appelle une post-décharge en flux. Ce sont les atomes N et O de cette décharge qui viendront, dans les conditions appropriées, entrer en collisions dans la chambre de stérilisation pour y créer des molécules excitées NO*, engendrant ainsi l’émission d’une quantité appréciable de photons UV. Ceux-ci constituent, dans le cas présent, l’agent biocide qui va s’attaquer directement au bagage génétique du micro-organisme (bactéries, virus) que l’on souhaite inactiver. L’utilisation d’une lointaine post-décharge évite du même coup la présence des agents érosifs de la décharge, comme les ions et les métastables. L’un des problèmes de cette méthode de stérilisation est la réduction du nombre de molécules NO* créées par suite de la perte des atomes N et O, qui sont des radicaux connus pour interagir avec les surfaces, sur les parois des matériaux des DM que l’on souhaite stériliser. L’objectif principal de notre travail est de déterminer l’influence d’une telle perte en surface, dite aussi réassociation en surface, par l’introduction de matériaux comme le Téflon, l’acier inoxydable, l’aluminium et le cuivre sur le taux d’inactivation des spores bactériennes. Nous nous attendons à ce que la réassociation en surface de ces atomes occasionne ainsi une diminution de l’intensité UV et subséquemment, une réduction du taux d’inactivation. Par spectroscopie optique d’émission (SOE), nous avons déterminé les concentrations perdues de N et de O par la présence des matériaux dans le stérilisateur, ainsi que la diminution de l’émission UV en découlant. Nous avons observé que cette diminution des concentrations atomiques est d’autant plus importante que les surfaces sont catalytiques. Au cours de l’étude du phénomène de pertes sur les parois pour un mélange N2-%O2 nous avons constaté l’existence d’une compétition en surface entre les atomes N et O, dans laquelle les atomes d’oxygènes semblent dominer largement. Cela implique qu’au-delà d’un certain %O2 ajouté à la décharge N2, seuls les atomes O se réassocient en surface. Par ailleurs, l’analyse des courbes de survie bi-phasiques des micro-organismes a permis d’établir une étroite corrélation, par lien de cause à effet, entre la consommation des atomes N et O en surface et la diminution du taux d’inactivation des spores dans la première phase. En revanche, nous avons constaté que notre principal agent biocide (le rayonnement ultraviolet) est moins efficace dans la deuxième phase et, par conséquent, il n’a pas été possible d’établir un lien entre la diminution des concentrations et le taux d’inactivation de cette phase-là. / The use of plasmas to sterilize medical devices (MDs) is a research field, which really started only at the end of the 90’s. Plasmas under adequate conditions allow achieving low-temperature (≤ 65°C) sterilization, as required by MDs made from polymers, in contrast to heat-driven sterilization methods, and provide a non-toxic method, in contrast to chemical processes such as performed, for example, with ethylene oxide (EtO). The Groupe de physique des plasmas laboratories at Université de Montréal is working on the design and testing of a sterilizer, which has the peculiarity of utilizing the species outflowing from a N2-%O2 discharge at reduced pressure (2-8 Torrs), which is called a plasma flowing-afterglow. It is the N and O atoms of this discharge mixture that, under appropriate conditions, interact in the sterilization chamber to form NO* excited molecules, generating a significant level of UV photons. These are, in the present case, the actual biocidal agent which will create lethal lesions on the genetic material of the microorganisms (bacteria, viruses) that should be inactivated. Using a flowing late afterglow instead of the discharge itself enables us to avoid the presence of the erosive agents of the discharge (ions, metastable-state particles). A major problem of this sterilization method is the reduction in the concentration of NO* molecules resulting from the losses of the N and O atoms on the surfaces of the MD materials that we want to sterilize. These radicals are, in fact, well-known to interact with surfaces and recombine on them. The main aim of our work is to determine the loss level of such atoms following their surface recombination on materials such as Teflon, stainless steel, aluminum and copper and the corresponding influence of such losses on the inactivation rate of bacterial spores. We can expect that surface recombination of these atoms leads to a reduction in the UV emission intensity and, as a result, in a reduction in the inactivation rate. Using optical emission spectroscopy (OES), we have determined the loss of N and O concentrations resulting from the presence of various materials in the sterilizer chamber as well as the corresponding decrease in UV emission intensity. We have observed that this reduction in atomic concentrations increases with the catalytic properties (recombination coefficient) of these materials. While examining the surface recombination phenomenon on these various materials, we have noticed a competition between the surface recombination of N and O atoms where the latter appear to play the main role. This implies that above a certain percentage of O2 added to N2, only the O atoms do recombine on these surfaces. On the other hand, the analysis of the bi-phasic survivor curves has enable us to show a strong correlation between the consumption of N and O atoms on surfaces and the reduction in the inactivation rate coefficient in the first phase of the survivor curve. We have also observed that our main biocidal agent is less efficient in the second phase of the survivor curve and, as a result, it was not possible to make a connection between the reduction in N and O atom concentration and the inactivation rate of the second phase.