Background Among adolescents and young adults with DSM-IV alcohol use disorders (AUDs), there are inter-individual differences in the speed of transition from initial alcohol use (AU) to AUD. AUDs are highly co-morbid with other mental disorders. The factors associated with rapid transition from first AU to AUD remain unknown and the role of mental disorders in rapid transitions is unclear. Given this background we examined (1) whether prior anxiety, mood, externalizing and non-alcohol substance use disorders are related to the risk and speed of transition from first AU to DSM-IV alcohol abuse (AA) and alcohol dependence (AD) and (2) whether early age of onset of prior mental disorders (PMDs) is a promoter of rapid transition. Method A total of 3021 community subjects (97.7% lifetime AU) aged 14–24 years at baseline were followed up prospectively for up to 10 years. AU and mental disorders were assessed with the DSM-IV/M-CIDI. Results Among subjects with lifetime AU, several PMDs, such as specific phobia, bipolar disorder and nicotine dependence, were associated with an increased risk of AUD independent of externalizing disorders. Associations of PMDs with the speed of transition to AUDs were mostly weak and inconsistent. Only social phobia and externalizing disorders were associated with faster transitions to AD even after adjustment for other PMDs. Earlier age of onset of PMD was not associated with rapid transition. Conclusions Mental disorders are associated with the risk of AUD. With the possible exception of social phobia and externalizing disorders, they do not promote rapid transition, even if they occur particularly early. Future research needs to identify factors relevant to rapid transition to AUD.

The system code TRACE is the latest development of the U.S. Nuclear Regulatory Commission (US NRC). TRACE, developed for the analysis of operational conditions, transients and accidents of light water reactors (LWR), is a best-estimate code with two fluid, six equation models for mass, energy, and momentum conservation, and related closure models. Since TRACE is mainly applied to LWR specific issues, the validation process related to innovative nuclear systems (liquid metal cooled systems, systems operated with supercritical water, etc.) is very limited, almost not existing. In this work, essential contribution to the validation of TRACE related to lead and lead alloy cooled systems as well as systems operated with supercritical water is provided in a consistent and corporate way. In a first step, model discrepancies of the TRACE source code were removed. This inconsistencies caused the wrong prediction of the thermo physical properties of supercritical water and lead bismuth eutectic, and hence the incorrect prediction of heat transfer relevant characteristic numbers like Reynolds or Prandtl number. In addition to the correction of the models to predict these quantities, models describing the thermo physical properties of lead and Diphyl THT (synthetic heat transfer medium) were implemented. Several experiments and numerical benchmarks were used to validate the modified TRACE version. These experiments, mainly focused on wall-to-fluid heat transfer, revealed that not only the thermo physical properties are afflicted with inconsistencies but also the heat transfer models. The models for the heat transfer to liquid metals were enhanced in a way that the code can now distinguish between pipe and bundle flow by using the right correlation. The heat transfer to supercritical water was not existing in TRACE up to now. Completely new routines were implemented to overcome that issue. The comparison of the calculations to the experiments showed, on one hand, the necessity of these changes and, on the other hand, the success of the new implemented routines and functions. The predictions using the modified TRACE version were close to the experimental data. After validating the modified TRACE version, two design studies related to the Generation IV International Forum (GIF) were investigated. In the first one, a core of a lead-cooled fast reactor (LFR) was analyzed. To include the interaction between the thermal hydraulic and the neutron kinetic due to temperature and density changes, the TRACE code was coupled to the program system ERANOS2.1. The results gained with that coupled system are in accordance with theory and helped to identify sub-assemblies with the highest loads concerning fuel and cladding temperature. The second design which was investigated was the High Performance Light Water Reactor (HPLWR). Since the design of the HPLWR is not finalized, optimization of vital parameters (power, mass flow rate, etc.) are still ongoing. Since most of the parameters are affecting each other, an uncertainty and sensitivity analysis was performed. The uncertainty analysis showed the upper and lower boundaries of selected parameters, which are of importance from the safety point of view (e.g., fuel and cladding temperature, moderator temperature). The sensitivity study identified the most relevant parameters and their influence on the whole system.

SUMMARY According to many Lithuanian teachers, the problem of dropouts is a social, cultural, economic and managerial problem. Unwilling to study juvenile and dropouts usually add to the ranks of unskilled labor force, unemployed individuals and even criminal groups. Analysis of the available literature showed that there have been no consistent researches carried out in connection to the problem of dropouts at vocational schools. The objective of this paper is to identify the reasons of dropping out at vocational school and preventive measures applied in this regard. In order to achieve this objective, the scope of dropouts at Lithuanian vocational schools, experience of EU countries in tackling the problem of dropping out of young individuals aged 18 - 24 from the education system were reviewed in addition to the analysis of preventive potential. The second part of the paper contains research results which reveal the reasons why students susceptible to dropping out do lease schools, what teachers and managers think about the problem of dropping out. Analysis of the opinions of students and teachers demonstrated that the basic reason for dropping out from vocational schools, as pointed out by one third of students at risk and teachers, i.e., nonattendance, is related to: - insufficient subsistence funds, i.e., will to work in Lithuania or abroad; - learning failures accompanying students from comprehensive schools; - selected profession, i.e., having experienced practical... [to full text]

Aims: To investigate the gender differences in the patterns of cannabis use (CU), namely frequency, times of day, social context and methods and in their association with DSM-IV cannabis dependence. Methods: A sample of 3,904 students from German universities was recruited via an internet survey. Logistic regressions and associated areas under the ROC curve (AUC) were calculated among current cannabis users (at least once a month, n = 843). Results: CU using a water pipe was more often reported by males (50 vs. 34.6%). Usual CU ‘before going to sleep at night’ was more often reported by females (47.3 vs. 35.7%). Most CU patterns showed a similar association with DSM-IV cannabis dependence in both genders. The association of CU ‘with strangers’ was stronger in females (AUC 0.68 vs. AUC 0.56). Slightly different multiple models were found (females AUC 0.86, males AUC 0.77). Conclusions: There are considerable gender differences in the CU patterns and, thus, in the way CU functions. In the association of CU patterns with cannabis dependence, the similarities are rather great. Examining the CU patterns might make a considerable contribution to the better detection of high-risk population segments for prevention and early intervention in both genders. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Notre étude porte sur deux échantillons de patients Tunisiens : un groupe clinique composé de sujets (N = 41) diagnostiqués trouble de personnalité limite par leur psychiatre en référence aux critères du DSM-IV (APA, 2003) et un groupe témoin composé de patients schizophrènes (N = 27). Nous avons utilisé le test de Rorschach en Système intégré (Exner, 1993) et avons fixé comme premier objectif de dégager les caractéristiques du fonctionnement des patients limites au Rorschach selon les paramètres de l’organisation limite de la personnalité décrits par Kernberg (1997). Notre deuxième objectif est de vérifier si le fonctionnement de ces sujets, tel que traduit dans le Rorschach, permet de les différencier des sujets schizophrènes. Le troisième objectif est d’étudier, par une approche test re-test avec un intervalle de 6 à 9 mois, la stabilité des variables du Rorschach à travers le temps. Les résultats de notre étude montrent que les protocoles des patients limites diffèrent par rapport à certaines variables-clés (7 variables) de ceux des schizophrènes. Ces variables constituent des indicateurs pertinents du fonctionnement limite. Néanmoins, nous avons relevé une hétérogénéité à l’intérieur de notre échantillon de sujets limites. En effet, plusieurs niveaux de fonctionnements ont émergé à l’intérieur de ce groupe. Par ailleurs, il n’y a pas eu de différence significative entre la plupart des variables en T1 et T2 aussi bien chez les sujets limites que les schizophrènes. Toutefois, la stabilité semble dépendre du fonctionnement sous-jacent. / This study concerns two samples of Tunisian patients: a clinical group (N = 41) with subjects who received a diagnosis of Borderline personality disorder in reference to DSM-IV (APA, 2003) by their psychiatrist and a control group of schizophrenic patients (N = 27). We used the Rorschach comprehensive system (Exner, 1993) in order to identify, as a first purpose, the characteristics of the Rorschach’s borderline functioning based on the Kernberg’s description of the borderline organisation (1997). In parallel, we aimed, to verify whether the Rorschach’s functioning characteristics are able to distinguish our clinical group from the Schizophrenic group. Furthermore, both of groups were tested once in the beginning of our study and again, with an interval of 6 at 9 months in order to study the stability of the Rorschach’s variables. The results indicated that seven (7) variables distinguish our group of Borderline subjects from the schizophrenics. These variables represent highly relevant indicators of borderline functioning. Nevertheless, our clinical group is heterogeneous. In fact, different ranges of functioning have emerged. Elsewhere, there is no significant difference between the most variables in T1 and T2 but the stability may differ depending on the underlying functioning.

The disertation focuses on the presentation of meaning and purpose of the IV. Commandment today. It is based on the interpetation of the Old Testament. It deals with the social consequences of the changes in the Czech Republic after 1989 in relation to the family. It describes impacts these changes have on the respecting for IV. Comandment.

Ces travaux de thèse, effectués dans le cadre des études sur le retraitement des combustibles nucléaires usés par extraction-liquide-liquide, concernent l’étude cinétique d’extraction de l’uranium(VI) et du plutonium(IV) en milieu acide nitrique par un mélange d’extractants de type monoamide. Trois techniques ont été utilisées pour étudier les cinétiques d’extraction et identifier les régimes de transfert : la méthode de la goutte unique, la cellule d’extraction de Nitsch et la cellule à membrane tournante (RMC). Les résultats obtenus avec la goutte unique indiquent que les cinétiques de transfert d’U(VI) et Pu(IV) sont proches. Une étude hydrodynamique des gouttes et la modélisation du transfert de l’U(VI) ont montré que la présence d’une circulation interne à la goutte diminue les résistances diffusionnelles pour des tailles de goutte croissantes. L’influence de la concentration d’U(VI) dans le solvant sur la cinétique d’extraction a montré que le transfert d’U(VI) et Pu(IV) ralentit lorsque la concentration d’U(VI) en phase organique et la viscosité augmentent. L’ensemble de ces résultats couplé à l’étude du transfert de l’U(VI) par la cellule de Nitsch conduisent à supposer une cinétique gouvernée par la diffusion principalement localisée dans la phase organique. Les études réalisées avec la RMC ont permis de déterminer la constante chimique d’extraction de l’U(VI), du même ordre de grandeur que les cinétiques obtenues par la goutte unique et de confirmer la présence d’une réaction chimique interfaciale. Enfin, le transfert d’U(VI) et Pu(IV) s’avère 3 fois plus lent que celui par le TBP mais reste adapté pour un procédé d’extraction à l’échelle industrielle. / This thesis was conducted in the framework of the reprocessing of spent nuclear fuels. The kinetics extraction of uranium(VI) and plutonium(IV) by N,N-dialkylamides or monoamides in an aliphatic diluent were studied from an aqueous nitric solution using 3 different techniques: “single drop technique”, Nitsch cell and Rotating Membrane Cell (RMC). All these experiments were useful to attempt the identification of the transfer process between the phases which can be controlled by kinetic or diffusional regime. The kinetics of extraction of U(VI) by monoamides solvent seems to be similar to that of the Pu(IV). In general, molecular diffusion in organic phase slows down the extraction process and the limiting thickness of organic phase increases with solvent viscosity. The process in “single drop technique” seems to be controlled not only by diffusion but also by the chemical reaction. Then the extraction kinetics of U(VI) has been carried out by Nitsch cell and the RMC. Diffusionnal regime is the limiting step in Nitsch cell and the results confirm that molecular diffusion in organic phase should mainly control the kinetics transfer. Then experiments performed by the RMC indicate that the kinetics is in the same order as transfer coefficient obtained by “single drop” and the chemical reaction occurs at the interface. Finally, these results were compared with data obtained with a TBP solvent (tributyl phosphate) currently used in the PUREX process in order to estimate the interest of such a new solvent. The kinetics of extraction of U(VI) by this monoamide-based solvent is three times lower that of the TBP 30 % but remains fast and suitable for a future industrial process.

O progresso de projetos anteriores salientou a necessidade de tratar o problema dos softwares para detecção, a partir de bases de dados de publicações científicas, de tendências emergentes de pesquisa e desenvolvimento. Evidenciou-se a carência de aplicações computacionais eficientes dedicadas a este propósito, que são artigos de grande utilidade para um melhor planejamento de programas de pesquisa e desenvolvimento em instituições. Foi realizada, então, uma revisão dos softwares atualmente disponíveis, para poder-se delinear claramente a oportunidade de desenvolver novas ferramentas. Como resultado, implementou-se um aplicativo chamado Citesnake, projetado especialmente para auxiliar a detecção e o estudo de tendências emergentes a partir da análise de redes de vários tipos, extraídas das bases de dados científicas. Através desta ferramenta computacional robusta e eficaz, foram conduzidas análises de frentes emergentes de pesquisa e desenvolvimento na área de Sistemas Geradores de Energia Nuclear de Geração IV, de forma que se pudesse evidenciar, dentre os tipos de reatores selecionados como os mais promissores pelo GIF - Generation IV International Forum, aqueles que mais se desenvolveram nos últimos dez anos e que se apresentam, atualmente, como os mais capazes de cumprir as promessas realizadas sobre os seus conceitos inovadores. / The progress of previous projects pointed out the need to face some problems of software for detecting emerging research and development trends from databases of scientific publications. It became evident the lack of efficient computing applications dedicated to this purpose that are artifacts of great usefulness to better planning research and development programs in institutions. A review of the currently available software was performed, in order to clearly delineate the opportunity to develop new tools. As a result, a software called Citesnake was implemented, designed particularly to help the detection and study of emerging trends from the analysis of networks of several types extracted from the scientific databases. Using this robust and effective computational tool, analyzes of emerging research and development trends were performed in the field of Generation IV Nuclear Power Generation Systems, in such a way to point out, among the most promising reactor types selected by the GIF - Generation IV International Forum, those that have better evolved over the past ten years and seem to be currently the most capable of fulfilling the promises made on their innovative concepts.

In this study the anchorage of Sn (IV) complexes on silica gel to obtain heterogeneous catalysts with potential activity in transesterification was investigated. The Sif-DMTDU e Sif-TBTU catalysts were synthesized and anchored on silica modified with trimethoxysilane, and Si-TBTM e o Si-DBTDM were anchored without silica modification. The complexes formation was confirmed by spectroscopy in the mid-infrared region, optical atomic emission spectrometry, nitrogen physisorption and determination of the surface area of the catalyst by BET method, thermogravimetry and scanning transmission electron microscopy. The Si-DBTDM showed the largest tin content in silica, 17.3 %, followed by Sif-DMTDU with 12.0 %, Si-TBTM with 7.4 % and 5.0% for Sif-TBTU. The heterogenized compounds and their homogeneous equivalents, were tested for the transesterification of ethyl acetate in order to examine the catalytic behavior in this type of reaction. The transesterification were performed in vials, in order to convert the ethyl acetate in methyl acetate. The reaction products were characterized by gas chromatography. All homogeneous and heterogeneous catalysts tested, exhibit catalytic activity at the conditions employed. The reactivity order for homogeneous catalysts was DBTDM> DMTDU> TBTU> TBTM. When these species are heterogenized, the same order of reactivity was observed, but is necessary more time to achieve the same catalytic activity observed in the case of the homogeneous complex. In reuse and leaching tests, is observed the loss of Sn (IV) of the silica matrix, but the catalysts remained active for up to 10 reaction cycles, which represents 20 hours of reaction. The SIf-DMTDU and Si-DBTDM catalysts were more active than Sif TBTU and Si-TBTM, however Sif-TBTU was more advantageous, since from 4º reuse it showed the highest activity. Finally, at the conditions studied, the use of the complex base Sn (IV) anchored on silica proved to be very promising in the transesterification reaction. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Neste trabalho foi investigada a ancoragem de complexos de Sn(IV), em sílica gel, a fim de obter catalisadores heterogêneos, com potencial atividade na reação de transesterificação. Os catalisadores Sif-DMTDU e Sif-TBTU foram sintetizados e ancorados em sílica modificada com trimetoxissilano, enquanto o Si-TBTM e o Si-DBTDM foram ancorados sem a necessidade de modificar a superfície da sílica. A formação dos complexos foi confirmada por espectroscopia na região do infravermelho médio, espectrometria ótica de emissão atômica, fisissorção de nitrogênio e determinação da área superficial dos catalisadores pelo método de BET, termogravimetria e microscopia eletrônica de varredura e de transmissão. O Si-DBTDM apresentou o maior teor de estanho na sílica, 17,3 %, seguido do Sif-DMTDU que apresentou 12,0 %, Si-TBTM que apresentou 7,4 % e o Sif-TBTU 5,0 %. Os compostos heterogeneizados e seus respectivos homólogos foram testados na transesterificação do acetato de etila, com o intuito de analisar o comportamento catalítico nesse tipo de reação. As reações de transesterificação foram realizadas em frascos tipo vial, visando à conversão do acetato de etila em acetato de metila. Os produtos reacionais obtidos foram caracterizados através da cromatografia gasosa. Todos os catalisadores homogêneos e heterogêneos testados apresentaram atividade catalítica e, nas condições empregadas, a ordem de reatividade para os catalisadores homogêneos foi DBTDM>DMTDU>TBTU>TBTM. Quando tais espécies foram heterogeneizadas, a mesma ordem de reatividade foi observada, porém houve necessidade de um maior tempo reacional para atingir a mesma atividade catalítica observada no caso dos complexos homogêneos. Nos testes de reuso e lixiviação, foi possível observar a perda de Sn(IV) da matriz de sílica, porém os catalisadores se mantiveram ativos por até 10 ciclos reacionais, o que representa 20 horas de reação. Os catalisadores Sif-DMTDU e Si-DBTDM foram mais ativos que o Sif-TBTU e Si-TBTM, no entanto o Sif-TBTU foi mais vantajoso, uma vez que a partir do 4° reuso ele apresentou as maiores atividades. Por fim, nas condições estudadas, o uso de complexos a base de Sn(IV) ancorados em sílica mostrou-se bastante promissor na reação de transesterificação.

A monoetanolamina (MEA) é um composto bifuncional pertencente à classe dos amino-álcoois, muito utilizado em processos industriais envolvendo a remoção de gases ácidos como SO2 , CO2 e H2S. A resina Amberlite XAD-7 é uma resina não-iônica de polaridade intermediária muito utilizada em procedimentos de pré-concentração de compostos orgânicos e íons metálicos. Neste trabalho, estudou-se a interação entre a superfície da resina XAD-7 e a MEA. Massas conhecidas da resina foram colocadas em contato com soluções de MEA em concentrações conhecidas, sob agitação durante certo intervalo de tempo. A quantidade de MEA adsorvida foi calculada considerando-se a diferença entre a concentração inicial e a concentração remanescente no sobrenadante, ambas obtidas a partir de medidas de absorbância, com utilização da reação de Berthelot modificada. Modelos cinéticos de pseudo-primeira e -segunda ordens, além do modelo de difusão intra-partícula, foram aplicados aos dados experimentais obtidos no estudo cinético. Entre estes modelos aplicados, o de pseudo-segunda ordem apresentou excelente ajuste aos dados experimentais. O estudo realizado em um determinado tempo de contato e variando-se a concentração inicial de MEA forneceu resultados experimentais que foram aplicados a três modelos de isotermas (Langmuir, Freundlich e Dubinin-Radushkevich). Destes ajustes, que mostraram excelente concordância, foram obtidos diferentes parâmetros termodinâmicos que definiram algumas características do processo de adsorção. Finalmente, estudos preliminares evidenciaram a retenção de SO32- na superfície da resina XAD-7 modificada com MEA, mostrando a possibilidade da utilização da XAD- 2 7/MEA para extração de SO32- presente em soluções ou de SO2 recolhido em solução alcalina. / Monoethanolamine (MEA) is a bifunctional compound which belongs to the amino- alcohol group, and it is widely used in industrial \"sweetening process\", which is based on the acidic gas (such as SO2 , CO2 and H2S) absorption. Amberlite XAD-7 is a non-polar resin with an intermediate polarity used to pre-concentrate organic compounds and transition metals. In this work, the interaction between the resin surface and MEA was studied. Known amounts of the resin were kept in contact with aqueous solutions of MEA and shaked under a constant rotation and during some defined intervals of time. The amount of adsorbed MEA was calculated as the difference between the initial concentration and remained concentration in the supernatant solution, which was determined applying the Berthelot´s reaction and the spectrophotometry. Kinetic models of pseudo-first and -second orders and intra-particle diffusion model were applied on experimental data collected from the kinetic study. Among these methods, the pseudo-second order model fulled fit on those experimental data. The experiments carried out under a constant time, but by changing the initial MEA concentration, led to other experimental data which were applied to three different isotherm models (Langmuir, Freundlich e Dubinin-Radushkevich). Each model showed a good fit, and for each one, different thermodynamic parameters were calculated and used to describe some adsorption characteristics. Finally, preliminary studies on the retention of SO32- onto the resin surface, previously modified with MEA, showed the possibility to extract SO32- found in aqueous solutions or SO2 recovered in alkaline media.