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La modification des surfaces revêt un intérêt primordial dans de nombreux champs d'applications de la chimie, comme la chimie analytique et l'électronique moléculaire. Ce travail a porté sur l'étude de différentes monocouches liées de façon covalente à des surfaces conductrices (principalement le carbone) et préparées à partir de l'électroréduction de sels d'aryldiazonium. Ces monocouches organiques ont été fonctionnalisées avec des groupements terminaux électroactifs différents, et l'on s'est intéressé aux propriétés de transfert de charge (au sens large) des couches résultantes. Tout d'abord des couches portant un système redox simple à base de ferrocène ont été étudiées dans différents milieux organiques conventionnels et en milieu liquides ioniques. L'effet de l'éloignement du système redox vis-à-vis de la surface a été également analysé en variant la longueur du pont ancrant. Dans un second temps, les monocouches organiques ont été fonctionnalisées par des unités tétrathiafulvalène (TTF). Les TTF sont des molécules (donneur d'électrons) connues pour former des complexes à transfert de charge avec le tétracyanoquinodiméthane (TCNQ), accepteur d'électrons. La formation de complexes à transfert de charge entre des TTF immobilisées dans la monocouche et des dérivés TCNQ a été étudiée et modulée selon l'éloignement du TTF vis-à-vis de la surface (variation de la longueur du lien ancrant) et en fonction de la force de l'accepteur. Enfin, des monocouches avec des groupements terminaux de type fluorène ou spirobifluorène (SBF) ont été préparées. Le comportement bloquant vis-à-vis-du transfert d'électron a été étudié par microscopie électrochimique (SECM) en présence de deux médiateurs redox différents et la conductivité des couches a été évaluée par CP-AFM (microscopie à force atomique – mesure de courants locaux). Il est montré que les propriétés de transfert/transport de charges sont influencées par l'encombrement stérique associé au fluorène ou au SBF (variation de la substitution). Ces monocouches organiques stables, bien organisées apparaissent très prometteuses comme composants dans des dispositifs d'électronique moléculaire. / Surface modification is of paramount importance in many fields of chemistry like analytical chemistry and molecular electronics. This work deals with the study of different monolayers covalently bound on conducting (mainly carbon) surfaces, and produced from the electroreduction of aryldiazonium salts. By introducing electroactive components in the resulting monolayers, the different studies in this work mainly focused on charge-transfer properties (in a large sense). First, monolayers bearing simple redox-active ferrocenyl terminal groups were investigated. The electrochemical behavior of these monolayers was analyzed in different conventional organic media and in ionic liquids (RTILs) and by varying the length of the bridging unit between the surface and the ferrocene groups. Second, redox-active tetrathiafulvalene (TTF) molecules were used to functionalize the monolayers. TTF molecules are well-known donor molecules able to form charge-transfer complexes with tetracyanoquinodimethane (TCNQ) as an electron-acceptor. The formation of charge-transfer complexes between immobilized TTF and TCNQ derivatives was studied and modulated by varying the chain length of the bridging unit between the TTF donor and the surface and by varying the electron-withdrawing ability of the TCNQ acceptors. Third, monolayers with fluorene and spirobifluorene (SBF) terminal groups were prepared. The blocking behavior towards electron transfer was studied by electrochemical microscopy (SECM) with two redox mediators and the conductivity of the layers was investigated by CP-AFM (Conducting Probe-Atomic Force Microscopy). Effects due to the steric hindrance of the fluorene or SBF derivatives were evidenced. Such stable, organized and organic monolayers seem to be promising candidates for molecular electronic devices.

Hurricane is one of the most destructive and costly natural hazard to the built environment and its impact on low-rise buildings, particularity, is beyond acceptable. The major objective of this research was to perform a parametric evaluation of internal pressure (IP) for wind-resistant design of low-rise buildings and wind-driven natural ventilation applications. For this purpose, a multi-scale experimental, i.e. full-scale at Wall of Wind (WoW) and small-scale at Boundary Layer Wind Tunnel (BLWT), and a Computational Fluid Dynamics (CFD) approach was adopted. This provided new capability to assess wind pressures realistically on internal volumes ranging from small spaces formed between roof tiles and its deck to attic to room partitions. Effects of sudden breaching, existing dominant openings on building envelopes as well as compartmentalization of building interior on the IP were systematically investigated. Results of this research indicated: (i) for sudden breaching of dominant openings, the transient overshooting response was lower than the subsequent steady state peak IP and internal volume correction for low-wind-speed testing facilities was necessary. For example a building without volume correction experienced a response four times faster and exhibited 30-40% lower mean and peak IP; (ii) for existing openings, vent openings uniformly distributed along the roof alleviated, whereas one sided openings aggravated the IP; (iii) larger dominant openings exhibited a higher IP on the building envelope, and an off-center opening on the wall exhibited (30-40%) higher IP than center located openings; (iv) compartmentalization amplified the intensity of IP and; (v) significant underneath pressure was measured for field tiles, warranting its consideration during net pressure evaluations. The study aimed at wind driven natural ventilation indicated: (i) the IP due to cross ventilation was 1.5 to 2.5 times higher for Ainlet/Aoutlet>1 compared to cases where Ainlet/AoutletCFD based IP responses. Comparisons with ASCE 7-10 consistently demonstrated that the code underestimated peak positive and suction IP.

Developing next generation secondary batteries has attracted much attention in recent years due to the increasing demand of high energy and high power density energy storage for portable electronics, electric vehicles and renewable sources of energy. This dissertation investigates sulfur based advanced electrode materials in Lithium/Sodium batteries. The electrochemical performances of the electrode materials have been enhanced due to their unique nano structures as well as the formation of novel composites. First, a nitrogen-doped graphene nanosheets/sulfur (NGNSs/S) composite was synthesized via a facile chemical reaction deposition. In this composite, NGNSs were employed as a conductive host to entrap S/polysulfides in the cathode part. The NGNSs/S composite delivered an initial discharge capacity of 856.7 mAh g-1 and a reversible capacity of 319.3 mAh g-1 at 0.1C with good recoverable rate capability. Second, NGNS/S nanocomposites, synthesized using chemical reaction-deposition method and low temperature heat treatment, were further studied as active cathode materials for room temperature Na-S batteries. Both high loading composite with 86% gamma-S8 and low loading composite with 25% gamma-S8 have been electrochemically evaluated and compared with both NGNS and S control electrodes. It was found that low loading NGNS/S composite exhibited better electrochemical performance with specific capacity of 110 and 48 mAh g-1 at 0.1C at the 1st and 300th cycle, respectively. The Coulombic efficiency of 100% was obtained at the 300th cycle. Third, high purity rock-salt (RS), zinc-blende (ZB) and wurtzite (WZ) MnS nanocrystals with different morphologies were successfully synthesized via a facile solvothermal method. RS-, ZB- and WZ-MnS electrodes showed the capacities of 232.5 mAh g-1, 287.9 mAh g-1 and 79.8 mAh g-1 at the 600th cycle, respectively. ZB-MnS displayed the best performance in terms of specific capacity and cyclability. Interestingly, MnS electrodes exhibited an unusual phenomenon of capacity increase upon cycling which was ascribed to the decreased cell resistance and enhanced interfacial charge storage. In summary, this dissertation provides investigation of sulfur based electrode materials with sulfur/N-doped graphene composites and MnS nanocrystals. Their electrochemical performances have been evaluated and discussed. The understanding of their reaction mechanisms and electrochemical enhancement could make progress on development of secondary batteries.

Le but de cette thèse a été d'étudier les propriétés structurales et optiques de puits quantiques (PQs) d’InGaN/(Al)GaN obtenus par épitaxie en phase vapeur d’organométalliques. Différentes approches ont été mises en œuvre pour atteindre une émission dans le vert-jaune: la première utilisant une concentration d'indium ≥ 20% avec un PQ d’InGaN d’épaisseur <3.0 nm et vice versa. L'effet d'une couche d’encapsulation a également été étudié. Les techniques de microscopie à force atomique, de diffraction des rayons X, de photoluminescence (PL) et surtout de microscopie électronique à transmission (MET) ont été utilisées pour caractériser ces structures. Les épaisseurs des PQs et les compositions en indium ont été déterminées par le traitement numérique des franges de réseau dans les images MET haute résolution en section transverse. Un traitement original a été développé pour analyser quantitativement les fluctuations de l’épaisseur des PQs. L'analyse structurale des PQs ayant une composition en In élevé a montré que les défauts structuraux sont créés dans les PQs. La nature et la densité de ces défauts ont été déterminées et différents mécanismes pour leur formation ont été proposés. Il a également été montré que quelques monocouches d’encapsulation de GaN ou d’AlGaN déposées à la température de croissance des PQs limitent l’évaporation et/ou la diffusion d’indium. Ce procédé permet d’étendre la longueur d'onde d'émission avec une réduction de la dégradation de l'efficacité de la PL. Mon travail propose quelques pistes afin d'obtenir un bon compromis entre les paramètres contradictoires qui régissent l'efficacité des PQs émettant dans le vert-jaune. / The goal of this thesis was to study the structural and optical properties of InGaN/(Al)GaN multiple QWs grown by metal organic chemical vapor deposition. Different approaches have been implemented to achieve green-yellow emission: high indium concentration (≥ 20%) with low InGaN QW thickness (< 3 nm) or vice versa. Moreover, the effect of a capping layer on top of the QWs has also been investigated. Atomic force microscopy, X-ray diffraction, room temperature photoluminescence (RTPL) and mainly transmission electron microscopy (TEM) techniques have been used to characterize these structures. The QW thicknesses and indium compositions have been determined by digital processing of lattice fringes in cross-sectional high resolution TEM images. An original treatment has been developed to analyze quantitatively InGaN QW thickness fluctuations. The structural analysis of multiple QWs with high indium composition has shown that structural defects are created in the QWs. The nature and the density of these defects have been determined and different mechanisms for their formation have been proposed. It has also been shown that a few monolayers of AlGaN or GaN capping layers deposited at the InGaN QW growth temperature prohibited indium evaporation and/or diffusion. It therefore helps to extend the emission wavelength with a reduced degradation of the RTPL efficiency. My work offers a few ways to obtain a good compromise between the conflicting parameters that govern the efficiency of QWs emitting in the green-yellow spectrum range.

The graduation theses is focused on an application of logistics in food company. Theoretical part defines terms like stocking, manipulation units, wraps, material flow etc. The application part is based on the logistics in Povltavské mlékárny, a. s. It describes different departments like purchase (and also program Milsoft), estimates of sale, finished stock room and fleet department. The second part of the application part is based on the thoughts and calculation of sufficient capacity of the finished stock room after implementation of laboratory tests for listeria.

Bakgrund: World Health Organization, WHO har arbetat fram en checklista för säker kirurgi, som skall stötta arbetslaget i arbetet kring patienten. Checklistans syfte är att förbättra kommunikationen i arbetslaget och minska komplikationer och dödsfall i samband med kirurgi. Studiens syfte var att undersöka operations- och anestesisjuksköterskors upplevelser av att använda checklista för säkerhet vid operationer i sitt dagliga arbete. Metod: Studien var en kvalitativ intervjustudie som genomförts i fokusgrupper med operationssjuksköterskor i ena gruppen och anestesisjuksköterskor i andra. Data från två intervjuer analyserades med hjälp av en kvalitativ innehållsanalys. Resultat: Studien visade att brister fanns vid implementeringen och att personalen arbetade enligt gamla rutiner. Ett varierat intresse fanns till checklistan, vilket resulterade i en varierad följsamhet i användandet. Resultatet visade på att kommunikationen förbättras och att checklistan synliggjorde alla medarbetarna och ökade möjligheten till att alla kunde känna sig delaktig i vården kring patienten. Vid användning av checklistan reds frågetecken ut och checklistan skapade ett öppet klimat där personalen kunde ta upp eventuella frågetecken som fanns. Resultatet i studien visar dock på att checklistan inte löser alla kommunikationsproblem, då det framkommer att dåliga attityder och bristande respekt till varandra fanns och försvårade användandet. Konklusion: Operation -och anestesisjuksköterskorna ansåg att checklistan var ett bra verktyg när det gäller patientsäkerhet, kommunikation och teamarbete men att det fanns brister i följsamheten. De ansåg att användandet av checklistan var personbundet och att det trots checklistans tydliga utformning ändå fanns frågetecken hos personalen, speciellt vem som ansvarade att den blev gjord.

The effects of ambient room temperature on social cognition were examined in the current study. This study included 202 participants who completed a computer-based survey consisting of eight items measuring participants’ self-perception and desired social dynamics. I included these constructs because they serve to empirically examine the claims put forth by the Socio-Relational Framework of Expressive Behavior (Vigil, 2009). Participants completed the survey in experimental settings with the ambient room temperature ranging from 67.8 °F to 77.2 °F. I identified several important relationships that support the current theoretical framework, such as the differential desire for either affiliative or avoidant social responses, and the differential inflation of either empowerment or trustworthiness descriptors in colder and warmer conditions, respectively. Implications of the findings for future research are discussed.

The purpose of the present study was to examine general loneliness, hospital loneliness, and the patient-physician relationship in regards to their associations with Bone Marrow Transplant (BMT) recovery outcome variables (days until engraftment and quality of life). Fifteen (66.7% female, 33.3% male; 93.3% white, 6.7% Black/African American; average age 61.73) individuals who had an allogeneic or autologous BMT at The Mayo Clinic of Jacksonville completed the FACT-BMT, UCLA-Loneliness Scale Version 3, the CARE Measure, and provided disease and treatment information at the 6 month posttransplant date (+/- 30 days). Patients recovering from BMT indicated significantly higher scores of hospital loneliness in comparison to their general loneliness scores. This increase is believed to represent the outcome of experiencing hospital isolation during the post-transplant recovery process. Increases in hospital loneliness were marginally significant in predicting decreases in the patients overall quality of life. The patient physician consultational relationship was found to have a significant relationship with the number of days until engraftment, however the direction of the relationship was opposite the hypothesized direction. This may suggest that engraftment influences the quality of the relationship instead of vice versa. These results imply that there is a relationship between hospital isolation and increases in the amount of loneliness experienced during recovery from a BMT. Loneliness has been found to have a negative relationship with a number of physiological and quality of life outcomes. The present study also elucidates possible correlates with the patient-physician relationship.

Twenty years ago, kindergarten was a year of informal education designed to help a child develop some readiness skills, adjust to school, adjust socially and learn through play. Readiness for elementary education was defined in terms of attitude and motivation rather than in specific academic achievements. The hazards of the academic model for young children is supported by recent research. Elkind (1986), for example, confirms that young children do not learn in the same ways as older children and adults. Because the world of things, people, and language is so new to infants and young children, they learn best through direct encounters with their world rather than through formal education. During the '80s there has been an increase in the number of high-risk children entering kindergarten who may not be ready for that experience. Perhaps in response to this trend, kindergarten, rather than serving as a readiness program for future schooling, has become an experience for which children need to be prepared entering kindergarten. The National Association of Early Childhood (1987) notes that expectations have become increasingly high and unrealistic, as the curriculum from upper grades has been pushed down to lower levels, thus doom large numbers of young children to the increased possibility of failure. As a result of this change, there has been quite a controversy over the policy of kindergarten retention. Although grade retention is widely practiced at all levels, research suggests that it does not help children to "catch up." While retained children may appear to do better in the short term, they are at much greater risk for failure than are their non-retained peers (Shepard and Smith, 1990). The provision of an extra year of schooling prior to first grade is intended to protect unprepared children from entering too soon into a demanding academic environment where, 'it is thought, they will almost surely experience failure. Yet Shepard and Smith (1988) note that, "depending on the philosophical basis of kindergarten retention, which differs profoundly from one district to the next, the extra year is meant either to be a time for immature children to grow and develop learning readiness or a time to work on deficient prereading skills" (p. 34). So the criteria by which retention decisions are made are critical. The question of which criteria determine a child's kindergarten retention becomes paramount. The study examines this question by addressing the following issues: 1. Current practices regarding kindergarten retention;2. The percentage of kindergartners retained each year (locally and statewide); 3. The effects of kindergarten retention; 4. The ways in which teacher pressure, parents, standardized tests, and basal reading programs contribute to kindergarten retention; and 5. Alternatives to kindergarten retention. There will always be a group of children who lag behind their kindergarten classmates. Before we create a new program, however, we need to examine the effects of kindergarten retention. It is the intent of this study to provide county school supervisors and others with information which would enable them to take action to reverse the negative effects of past practices. This information can assist those responsible for decision-making as they struggle to make the correct decisions regarding the placement of young children.