Past ultraviolet and optical observations of stars hosting close-in Jupiter-mass planets have shown that some of these stars present an anomalously low chromospheric activity, significantly below the basal level. For the hot Jupiter planet host WASP-13, observations have shown that the apparent lack of activity is possibly caused by absorption from the intervening interstellar medium (ISM). Inspired by this result, we study the effect of ISM absorption on activity measurements (S and log R'(HK) indices) for main-sequence late-type stars. To this end, we employ synthetic stellar photospheric spectra combined with varying amounts of chromospheric emission and ISM absorption. We present the effect of ISM absorption on activity measurements by varying several instrumental (spectral resolution), stellar (projected rotational velocity, effective temperature, and chromospheric emission flux), and ISM parameters (relative velocity between stellar and ISM Ca II lines, broadening b-parameter, and Ca II column density). We find that for relative velocities between the stellar and ISM lines smaller than 30-40 km s(-1) and for ISM Ca II column densities log N-CaII greater than or similar to 12, the ISM absorption has a significant influence on activity measurements. Direct measurements and three dimensional maps of the Galactic ISM absorption indicate that an ISM Ca II column density of log N-CaII = 12 is typically reached by a distance of about 100 pc along most sight lines. In particular, for a Sun-like star lying at a distance greater than 100 pc, we expect a depression (bias) in the log R'(HK) value larger than 0.05-0.1 dex, about the same size as the typical measurement and calibration uncertainties on this parameter. This work shows that the bias introduced by ISM absorption must always be considered when measuring activity for stars lying beyond 100 pc. We also consider the effect of multiple ISM absorption components. We discuss the relevance of this result for exoplanet studies and revise the latest results on stellar activity versus planet surface gravity correlation. We finally describe methods with which it would be possible to account for ISM absorption in activity measurements and provide a code to roughly estimate the magnitude of the bias. Correcting for the ISM absorption bias may allow one to identify the origin of the anomaly in the activity measured for some planet-hosting stars.

The complexity of the processes whereby organic species are degraded in the atmosphere prevents many of the individual species (intermediates or products) from being unambiguously identified. Laboratory work necessarily focuses therefore on studies of idealised proxies with the aim of increasing general understanding of the physical and chemical processes which occur on particles and the types of species which they produce. Studies of the ubiquitous proxy oleic acid have resulted in the development of complex reaction schemes describing the various products and intermediates. These schemes include a diverse range of reactions and rates, thus highlighting the complications associated even with a relatively simple system. This thesis describes novel experimental studies designed to increase understanding of heterogeneous ozonolysis reactions of organic species in the aerosol phase using infrared spectroscopy as the principal analytical method. Reactions have been studied in solution (supported by off-line mass spectrometry), in thin films and in aerosols. The sensitivity of the infrared technique has also enabled the kinetics of reactions in thin films and aerosols to be followed. These methods were applied to both single- and mixed-component systems. Product studies successfully identified a number of primary and secondary species in the ozonised systems, with the secondary products formed from association reactions of the Criegee Intermediates with other species present (including self-reaction). In the mixed organic system these products were found to have originated from both a single reactant and from cross reactions between moieties from two different reactants. At low relative humidity, the ozonolysis reaction rates were monitored through the loss of the reactant species by infrared spectroscopy in the thin film and aerosol phase to give reactive uptake coefficients (gamma). At high relative humidity, the formation of products was followed. For the single-component thin films, the values obtained were gamma = 7.8 x 10-5 for stilbene and gamma = 2.0 x 10-7 for anthracene. In thin mixed films of oleic acid and stilbene, segregation occurred which prevented the effect of mixing upon the rate to be measured. A reactive uptake of gamma = 6.8 x 10-5 was obtained, identical to that of pure oleic acid. In the particle phase, the functional form of the reaction kinetics was found to be dependent on the type of particle. Pure stilbene and mixed oleic/stilbene aerosols were highly reactive and it proved necessary to treat reactive uptake coefficients under both diffusion-limited and surface-only reaction scenarios. For stilbene, the values obtained were gamma = 1.5 x 10-3 and gamma = 5.3 x 10-3 respectively. Spectral limitations in the mixed system meant that only the reaction of stilbene could be followed, giving gamma = 4.4 x 10-3 and gamma = 10.0 x 10-3 respectively. The enhanced rate in the mixture was attributed to secondary reactions. Anthracene and oleic acid coated particles were treated using a Langmuir-Hinshelwood mechanism from which the parameters KO3 (ozone partitioning coefficient) and kImax (maximum pseudo-first-order rate coefficient) could be extracted. For anthracene ozonolysis KO3 = 1.4 x 10-16 cm3 molecule-1 and kImax = 3.5x10-2 s-1. For oleic acid coated onto ammonium sulfate aerosols, values obtained were KO3 = 2.35 x 10-15 cm3 molecule-1 and kImax = 0.56 s-1 at low RH% and KO3 = 1.71 x 10-16 cm3 molecule-1 and kImax =0.33 s-1 at high RH%. The reduction in reactivity with increased RH% is principally attributed to the effect of surface polarity on ozone absorption.

Background Employee turnover is increasing and in order for companies to retain their workforce, internal marketing (IM) needs to be applied. With internal communication (IC) being seen as the key to implementing employee oriented strategies and activities to motivate employees and coordinate cross-functional efforts within IM, internal social media (ISM), as known for fostering communication among employees, needs to be investigated regarding its influence on employee engagement. Purpose The purpose of this study was to investigate the psychological conditions of employee engagement on ISM and their relationship to employee engagement on ISM, moderated by the managerial communication styles assertive, aggressive and passive. Method An explanatory sequential mixed methods design has been applied, combining the advantages of both quantitative and qualitative data collection. Starting with 86 self-completion questionnaires, the findings, obtained by the application of a factor analysis in conjunction with multiple regression analysis, have been deepened with 5 semi-structured interviews with the help of a thematic analysis. Results and Conclusions The psychological conditions of employee engagement on ISM are indeed positively related to employee engagement on ISM. Furthermore, the assertive managerial communication style has shown to have a moderating effect on the relationship between the psychological conditions of employee engagement on ISM and employee engagement on ISM. Even though the moderating effect has been negative, the assertive communication style has been found to have a positive effect on employee engagement on ISM itself.

Les bandes interstellaires diffuses (DIBs) représentent un mystère centenaire : aucune des centaines de bandes n'a pu être identifiée avec certitude avec un porteur spécifique, à l'exception très probable du cation buckminsterfullerène C60+. Il est obligatoire d'identifier et de quantifier la quantité de grosses molécules carbonées interstellaires qui sont très probablement responsables des DIBs : Les porteurs de DIB représentent probablement le plus grand réservoir de matière organique dans le Milieu interstellaire (MIS) et constituent un élément important de la chaîne des processus qui régissent le cycle interstellaire/stellaire. Jusqu'à récemment, la plupart des études liées aux DIBs avaient pour objectif unique l'identification des porteurs et, pour ce faire, se concentraient sur un nombre limité d'étoiles chaudes, distantes et rougies. Mon travail de recherche en thèse marque un tournant dans les méthodes et les objectifs associés aux DIBs, une évolution permise et motivée par le nombre croissant de relevés stellaires avec des instruments de plus en plus puissants à haute résolution spectrale. En effet, il est aujourd'hui possible de recueillir des quantités massives de données, tant du point de vue du nombre d'étoiles cibles que du point de vue du nombre de DIBs observées simultanément. Cela a ouvert la voie à de nouveaux types d'études, à des objectifs plus ambitieux et, surtout, à de nouvelles comparaisons potentielles avec les données de laboratoire. Ma thèse présente un grand nombre d'extractions de DIBs et quatre de ces nouvelles analyses :- Méthodes d'extraction et recherche de nouvelles DIBs.- Lien avec les propriétés physiques des nuages.- Constitution de bases de données pour la cartographie du MIS.- Tomographie des structures individuelles.- Des extractions de profils de DIBs basées sur des lignes de visée soigneusement sélectionnées, des études de leurs sous-structures et de leur variabilité spatiale et des contraintes subséquentes sur leurs porteurs moléculaires potentiels. / Diffuse interstellar bands (DIBs) represent a century-old mystery: none of the hundreds of bands could be identified with certainty with a specific carrier, at the very likely exception of the buckminsterfullerene cation C60+. Identifying and quantifying the amount of the large interstellar carbonaceous molecules that are very likely responsible for the DIBs is mandatory: DIB carriers likely represent the largest amount of organic matter in the Universe and are an important piece of the chain of processes that govern the interstellar/stellar cycle.Up to recently, most of the DIB studies have had as a unique goal the identification of the carriers, and to do so have been focusing on a limited number of hot, distant and reddened stars, using increasingly powerful instruments. This thesis marks a turning point in the methods and goals associated with the DIBs, an evolution allowed and motivated by the increasing number of stellar surveys with high multiplex instruments. As a matter of fact, it is possible today to gather massive amounts of data, both from the point of view of the number of target stars and from the point of view of the number of DIBs simultaneously observed. This has opened the way to new types of studies, more ambitious goals, and, importantly, new potential comparisons with laboratory data. This thesis presents a large number of DIB extractions and four of these novel analyses :- Methods of extraction and search for new DIBs.- Statistical studies of the link between DIB strengths and the physical properties of their hosting clouds.- Tomographic studies of the carriers on large and small spatial scales.- Line profile extractions based on carefully selected sightlines, studies of their substructures and spatial variability and subsequent constraints on their potential molecular carriers.

One can use unlicensed and often very inexpensive radios for unconventional communication (underwater- and underground) links. However, one can go further, and use these radios as sensors rather than communication links. Such communication links and sensors can have important application in hydroscience. While the attenuation of RF signals is high in these mediums, by using the wireless sensor network (WSN) paradigm of multi-hop and retransmission, reliable networks can be formed underwater and underground. One no longer needs to think of RF modules as only a source of data transmission. This revelation lends itself to thinking of these modules as inexpensive RF wave generators at prescribed unlicensed frequencies. Analyzing the received signal strength indicator (RSSI) of a link over time, one can infer changes in the medium from the changes in RSSI. In this thesis, I develop a simple mathematical model to relate changes in RSSI to changes in the medium. Additionally, five experimentally validated examples demonstrate the possibility of non-traditional uses for RF modules. Demonstrated sensor possibilities include soil moisture estimation, leaf wetness measurement, and vegetation water content estimation. This thesis served to validate the use of inexpensive unlicensed RF modules as more than just communication links through air, but as links in unconventional media, and more importantly as measurement instruments.

The pastoral problem being addressed has to do with the culture of consumerism and individualism that have influenced the culture of the Church. Within Western society, the “ism” culture, consisting of factors such as: hedonism, consumerism, materialism, secularism, relativism and individualism, has become very prominent. Christians often operate no differently than non-Christians, and this is problematic since Christians are called to be salt for the earth and light for the world (Matthew 5:13-16), a people set apart. In John 15:19, we are told that we were not made to be of this world, so we need to stop being influenced by the culture and instead allow the beauty of the Christian faith to influence the world. What is presented here is not just a hope to overcome consumerism and individualism, but an entire revamping of what it means to be Christian. It suggests the need for a culture change, which if Christians and church leadership focus on, has the power to solve other pastoral and ethical issues as well. Such a cultural change will lead to vibrancy among believers and will attract more people to the faith, as well.

This diploma thesis deals with the study and measurement of coexistence scenarios that can occur between the LTE and LoRa systems in the unlicensed ISM band 2.4 GHz. A common radio frequency band in which LTE and LoRa systems can coexist is defined. An appropriate laboratory measurement is proposed and realized, allowing automatized measurement of the defined coexistence scenarios. For this purpose, a personal computer, professional measurement equipment and software MATLAB are utilized. Functionality of the proposed concept is verified by extensive measurements. The obtained results are graphically shown and discussed in detail.

The diploma thesis is about designing device which monitors temperature and humidity. In the first part of thesis are explained basic terms, importance of key variables and on market offered products are described. After that the thesis describes device concept design with schematic designs. From designed schematics are described printed circuit board designs. Next part is about device commissioning and correction of errors caused by incorrect design. Last part is about program designing and device testing.

This diploma thesis deals with the flight data wireless transmission from aircraft to the ground station. This is the data sent from the acrobatic aircraft during races, specifically the GPS position and data from sensors of acceleration and rotation of the aircraft. It dealt with the theoretical analysis of the radio link and design of device that receives radio transmission. In aircraft it is dealt with data capturing and their deployment through the radio module. Data are sending to another post-processing on the ground station after receiving. There are two solutions of radio module and in the last part is a solution for capturing data from more airplanes.

This master's thesis is primarily focused on the design of an electronic access control system using the BodyCom technology. The first section describes the working principle of this technology and its influence on human body. The second section shows an application of this technology in construction options of the electronic access control system.