bluuebunny/crossref_metadata_2025 huggingface dataset:
MAPEAMENTO DE PRÁTICAS VIOLENTAS COMO DISPOSITIVO DE INTERVENÇÃO DA PSICOLOGIA NA ESCOLA
Authors: Bonamigo Irme Salete , Tondin Celso Francisco , Bortolossi Francieli , Seraglio Karina Paula , Schott Daniela Fernanda , Martinelli Maxemino
Published: September 2012

Este artigo discute o tema violências e escola, com base em pesquisa de levantamento realizada em 13 escolas públicas estaduais de Chapecó (SC), por meio da aplicação de questionário a 693 estudantes do ensino fundamental e médio, 147 professores e 123 famílias. São apresentadas as percepções dos participantes quanto à existência de agressões verbais, ameaças, agressões físicas, assédio sexual, danificação do patrimônio escolar, uso e tráfico de drogas,furtos e presença de aluno armado. A presença das práticas violentas no espaço escolar foi investigada nas relações entre alunos, alunos e professores, alunos e funcionários e professores/funcionários e familiares. Os dados analisados destacam a presença significativa de agressão verbal, ameaças, agressões físicas leves e furtos, entre alunos; danificação e furto de materiais e equipamentos da escola e apontam a existência menos frequente de agressões verbais e ameaças entre alunos e professores. Os resultados da pesquisa possibilitam identificar a necessidade de realização de pesquisas complementares para investigar singularidades presentes em cada escola, no que diz respeito às violências mapeadas. Podem ser utilizados, ainda,como dispositivos de intervenção do psicólogo na escola, para mobilizar os diferentes atores e contribuir para a reflexão de questões que atravessam a comunidade escolar, como o desafio de construir relações de respeito e cooperação entre os seus membros e de criar dispositivos de socialização e educação que contemplem outros modos de lidar com o conflito.
ASPECTOS SEMIÓTICOS DA TRANSIÇÃO INFÂNCIA-ADOLESCÊNCIA: O CONTEXTO DA ESCOLA
Authors: De Oliveira Campolina Luciana , Santos Lopes de Oliveira Maria Cláudia
Published: September 2012

Esta pesquisa aborda a relação de interdependência entre experiências sociais na escola e a transição da infância à adolescência de crianças de contexto urbano. Analisa as mudanças psicológicas e de significados que acompanham tal transição. Parte de uma perspectiva teórico-metodológica histórico-cultural, na qual a escola configura importante contexto de desenvolvimento do sujeito, em especial, nos primeiros anos de vida. Foi realizada uma pesquisa qualitativa envolvendo entrevistas individuais com crianças e adolescentes de 10 a 14 anos, mediadas por gravuras. As narrativas de entrevista revelaram que as experiências do brincar e as mudanças nos relacionamentos sociais na escola são fonte significativa de sentidos pessoais que marcam a transição infância-adolescência. Além disso, mudanças de interesse e atividades revelam que a transição não se resume às mudanças corporais, mas compreende a síntese complexa de elementos das experiências infantis e da adolescência, mediada por valores culturais.
PSICOLOGIA E POLÍTICA SOCIAL: O TRATO DA POBREZA COMO “SUJEITO PSICOLÓGICO”
Authors: Fernandes de Oliveira Isabel , De Oliveira Amorim Keyla Mafalda
Published: September 2012

A inserção dos psicólogos em instituições públicas no Brasil caracteriza-se pela ampliação das oportunidades de emprego para esses profissionais e pela expansão do público-alvo de suas atividades. Tal inserção põe em xeque os modelos sobre os quais se sustenta o exercício da profissão de psicólogo, sobretudo quando realizadas em locais que têm nas sequelas da “questão social” o foco da intervenção. Nesses espaços, mais que intervir no sofrimento psicológico,cabe ao psicólogo manejar situações cujos determinantes repousam nas condições estruturais da sociedade burguesa, especialmente aqueles resultantes da contradição fundamental entre capital e trabalho. A Psicologia, como ciência e profissão historicamente voltadas para a manutenção da ordem burguesa, ao inserir-se no campo das políticas sociais e responder pela execução dessas, vê-se diante de desafios que impelem as discussões sobre seu compromisso social, ético e político, que resultam em ações progressistas, de um lado, ou mantenedoras das condições de vida da população que agora assiste. Não obstante os desafios que o trabalho com a pobreza envolve, os psicólogos têm buscado estratégias de enfrentamento à sua própria paralisação diante de demandas que, além de variadas e amplas, devem ser tratadas dentro de um campo imbuído por embates políticos, mau uso da máquina pública e pouco direcionamento técnico. Assim, conclui-se que o trabalho no campo das políticas sociais demanda um reordenamento do arsenal teórico-técnico do psicólogo, mas, também, esbarra nas determinações macroestruturais do modo de produção capitalista.
UM ESTUDO SOBRE O AMOR: DIÁLOGOS ENTRE SIGMUND FREUD E ERICH FROMM
Authors: Schlösser Adriano , Dalfovo Daniel David , Delvan da Silva Delvan Josiane
Published: September 2012

Ao refletir-se sobre o amor na contemporaneidade, percebe-se que a configuração dos vínculos afetivo-amorosos vem sofrendo grandes transformações na atualidade, na qual a lógica consumista – uso e descarte – tem-se aplicado também às relações amorosas, valorizando-se a troca rápida de parceiros acima da manutenção dos relacionamentos. Tais mudanças tiveram impacto também na clínica psicanalítica, que tem a transferência como peça fundamental para sua realização, ou seja, necessita de um vínculo duradouro em que o analisando deposita sua libido e confiança na figura do analista, que só assim poderá direcionar essa libido possibilitando o processo psicanalítico. Com efeito, o presente trabalho teve por objetivo geral investigar o amor na abordagem psicanalítica a partir de Sigmund Freud e Erich Fromm, visando o desenvolvimento de um diálogo epistemológico entre esses dois autores acerca do amor, pontuando as aproximações e os distanciamentos conceituais identificados a partir da leitura e análise de suas obras. Como resultados, a literatura indicou que Fromm concebe o amor como uma arte, como uma atitude perante a vida, não abarcando, dessa forma,um caráter de exclusividade. Freud, em contrapartida, identifica o amor como o depósito da libido em um objeto, associando-o a aspectos pulsionais que estão a serviço de um ideal narcísico perdido.
O RELACIONAMENTO FISIOTERAPEUTA-PACIENTE NO MÉTODO PILATES
Authors: Medici Loureiro Subtil Marina , Lima de Souza Mariane , Garcia Agnaldo
Published: September 2012

O relacionamento entre terapeutas e pacientes tem sido foco de pesquisas em diversas profissões na saúde. No entanto, quando se refere à atuação da fisioterapia, o número de estudos ainda é reduzido, justificando a necessidade de maior aprofundamento sobre o assunto. O objetivo deste estudo foi conhecer e analisar as relações interpessoais estabelecidas entre fisioterapeuta e pacientes atendidos pelo método Pilates. Foram entrevistados dez pacientes de 31 a 73 anos, com diagnósticos clínicos variados, tempo de prática do Pilates entre três meses a quatro anos e com frequência semanal de duas a três vezes por semana. A coleta de dados deu-se por meio de entrevistas semiestruturadas as quais foram gravadas, transcritas e submetidas à análise qualitativa de conteúdo. O conteúdo das respostas foi organizado em cinco eixos temáticos: (a) as expectativas com o tratamento fisioterapêutico; (b) características de um bom tratamento; (c) a interrupção da prática do Pilates; (d) o que o Pilates representa na vida do paciente; e, (e) aspectos do relacionamento entre fisioterapeuta e paciente. Os dados sugerem que a tratamento fisioterapêutico permite a formação de um vínculo terapêutico específico entre os pacientes e o fisioterapeuta. Este relacionamento, incluindo a comunicação,foi considerado pelos pacientes um fator fundamental para o sucesso do tratamento e adesão ao tratamento.
RELAÇÃO ENTRE AÇÕES DE QUALIDADE DE VIDA NO TRABALHO E BEM-ESTAR LABORAL
Authors: Roriz Couto Priscila , Paschoal Tatiane
Published: September 2012

Graças às novas demandas do mundo laboral, as organizações têm buscado, cada vez mais,ações adequadas às necessidades de seus colaboradores. O presente estudo teve como objetivo investigar o impacto de atividades organizacionais voltadas à saúde do trabalhador sobre o bem-estar no trabalho. O bem-estar laboral foi definido como a prevalência de emoções positivas e a percepção do indivíduo de que, no seu trabalho, desenvolve seus potenciais e avança no alcance de suas metas de vida. Foram consideradas as seguintes ações voltadas à saúde: ginástica laboral, ambiente com musicalização, ambiente para relaxamento, automassagem e comemoração de aniversariantes. Participaram do estudo 130 trabalhadores de diferentes organizações do Distrito Federal. O bem-estar no trabalho foi medido pela EBET, instrumento já validado no Brasil, que operacionaliza o construto a partir de três fatores: afeto positivo, afeto negativo e realização pessoal no trabalho. Para avaliação das ações voltadas à saúde do trabalhador,foram desenvolvidos itens fechados específicos. Os dados foram analisados por meio de regressão múltipla stepwise, que considera apenas critérios estatísticos para a entrada das variáveis no modelo de predição. Verificou-se que quanto maior a frequência da participação em atividades como ginástica laboral, momentos de relaxamento, sala com musicalização, comemoração dos aniversariantes e automassagem, menor é o afeto negativo no trabalho. Afeto positivo e realização não foram preditos pelas ações de saúde. Os resultados são discutidos no texto e as limitações do estudo apontadas.
Overview of Animal Models of Obesity
Authors: Lutz Thomas A. , Woods Stephen C.
Published: September 2012

The focus of this overview is on the animal models of obesity most commonly utilized in research. The models include monogenic models in the leptin pathway, polygenic diet‐dependent models, and, in particular for their historical perspective, surgical and chemical models of obesity. However, there are far too many models to consider all of them comprehensively, especially those caused by selective molecular genetic approaches modifying one or more genes in specific populations of cells. Further, the generation and use of inducible transgenic animals (induced knock‐out or knock‐in) is not covered, even though they often carry significant advantages compared to traditional transgenic animals, e.g., influences of the genetic modification during the development of the animals can be minimized. The number of these animal models is simply too large to be covered in this unit. Curr. Protoc. Pharmacol. 58:5.61.1‐5.61.18. © 2012 by John Wiley & Sons, Inc.
Parallel Chemistry in the 21st Century
Authors: Long Alan
Published: September 2012

The tool chest of techniques, methodologies, and equipment for conducting parallel chemistry is larger than ever before. Improvements in the laboratory and developments in computational chemistry have enabled compound library design at the desks of medicinal chemists. This unit includes a brief background in combinatorial/parallel synthesis chemistry, along with a discussion of evolving technologies for both solid‐ and solution‐phase chemistry. In addition, there are discussions on designing compound libraries, acquisition/procurement of compounds and/or reagents, the chemistry and equipment used for chemical production, purification, sample handling, and data analysis. Curr. Protoc. Pharmacol. 58:9.16.1‐9.16.16. © 2012 by John Wiley & Sons, Inc.
Analyzing Protein‐Protein Interactions from Affinity Purification‐Mass Spectrometry Data with SAINT
Authors: Choi Hyungwon , Liu Guomin , Mellacheruvu Dattatreya , Tyers Mike , Gingras Anne‐Claude , Nesvizhskii Alexey I.
Published: September 2012

Significance Analysis of INTeractome (SAINT) is a software package for scoring protein‐protein interactions based on label‐free quantitative proteomics data (e.g., spectral count or intensity) in affinity purification–mass spectrometry (AP‐MS) experiments. SAINT allows bench scientists to select bona fide interactions and remove nonspecific interactions in an unbiased manner. However, there is no ‘one‐size‐fits‐all’ statistical model for every dataset, since the experimental design varies across studies. Key variables include the number of baits, the number of biological replicates per bait, and control purifications. Here we give a detailed account of input data format, control data, selection of high‐confidence interactions, and visualization of filtered data. We explain additional options for customizing the statistical model for optimal filtering in specific datasets. We also discuss a graphical user interface of SAINT in connection to the LIMS system ProHits, which can be installed as a virtual machine on Mac OS X or Windows computers. Curr. Protoc. Bioinform. 39:8.15.1‐8.15.23. © 2012 by John Wiley & Sons, Inc.
Using ProHits to Store, Annotate, and Analyze Affinity Purification–Mass Spectrometry (AP‐MS) Data
Authors: Liu Guomin , Zhang Jianping , Choi Hyungwon , Lambert Jean‐Philippe , Srikumar Tharan , Larsen Brett , Nesvizhskii Alexey I. , Raught Brian , Tyers Mike , Gingras Anne‐Claude
Published: September 2012

Affinity purification coupled with mass spectrometry (AP‐MS) is a robust technique used to identify protein‐protein interactions. With recent improvements in sample preparation, and dramatic advances in MS instrumentation speed and sensitivity, this technique is becoming more widely used throughout the scientific community. To meet the needs of research groups both large and small, we have developed software solutions for tracking, scoring and analyzing AP‐MS data. Here, we provide details for the installation and utilization of ProHits, a Laboratory Information Management System designed specifically for AP‐MS interaction proteomics. This protocol explains: (i) how to install the complete ProHits system, including modules for the management of mass spectrometry files and the analysis of interaction data, and (ii) alternative options for the use of pre‐existing search results in simpler versions of ProHits, including a virtual machine implementation of our ProHits Lite software. We also describe how to use the main features of the software to analyze AP‐MS data. Curr. Protoc. Bioinform. 39:8.16.1‐8.16.32. © 2012 by John Wiley & Sons, Inc.
Selecting, Acquiring, and Using Small Molecule Libraries for High‐Throughput Screening
Authors: Dandapani Sivaraman , Rosse Gerard , Southall Noel , Salvino Joseph M. , Thomas Craig J.
Published: September 2012

The selection, acquisition, and use of high‐quality small molecule libraries for screening is an essential aspect of drug discovery and chemical biology programs. Screening libraries continue to evolve as researchers gain a greater appreciation of the suitability of small molecules for specific biological targets, processes, and environments. The decision surrounding the makeup of any given small molecule library is informed by a multitude of variables, and opinions vary on best practices. The fitness of any collection relies upon upfront filtering to avoid problematic compounds, assess appropriate physicochemical properties, install the ideal level of structural uniqueness, and determine the desired extent of molecular complexity. These criteria are under constant evaluation and revision as academic and industrial organizations seek out collections that yield ever‐improving results from their screening portfolios. Practical questions including cost, compound management, screening sophistication, and assay objective also play a significant role in the choice of library composition. This overview attempts to offer advice to all organizations engaged in small molecule screening based upon current best practices and theoretical considerations in library selection and acquisition. Curr. Protoc. Chem. Biol. 4:177‐191 © 2012 by John Wiley & Sons, Inc.
Dealing with the Data Deluge: Handling the Multitude of Chemical Biology Data Sources
Authors: Guha Rajarshi , Nguyen Dac‐Trung , Southall Noel , Jadhav Ajit
Published: September 2012

Over the last 20 years, there has been an explosion in the amount and type of biological and chemical data that has been made publicly available in a variety of online databases. While this means that vast amounts of information can be found online, there is no guarantee that it can be found easily (or at all). A scientist searching for a specific piece of information is faced with a daunting task—many databases have overlapping content, use their own identifiers and, in some cases, have arcane and unintuitive user interfaces. In this overview, a variety of well‐known data sources for chemical and biological information are highlighted, focusing on those most useful for chemical biology research. The issue of using data from multiple sources and the associated problems such as identifier disambiguation are highlighted. A brief discussion is then provided on Tripod, a recently developed platform that supports the integration of arbitrary data sources, providing users a simple interface to search across a federated collection of resources. Curr. Protoc. Chem. Biol. 4:193‐209 © 2012 by John Wiley & Sons, Inc.
One‐Pot Multienzyme Synthesis of Lewis x and Sialyl Lewis x Antigens
Authors: Yu Hai , Lau Kam , Li Yanhong , Sugiarto Go , Chen Xi
Published: September 2012

L‐Fucose has been found abundantly in human milk oligosaccharides, bacterial lipopolysaccharides, glycolipids, and many N‐ and O‐linked glycans produced by mammalian cells. Fucose‐containing carbohydrates have important biological functions. Alterations in the expression of fucosylated oligosaccharides have been observed in several pathological processes such as cancer and atherosclerosis. Chemical formation of fucosidic bonds is challenging due to its acid lability. Enzymatic construction of fucosidic bonds by fucosyltransferases is highly efficient and selective but requires the expensive sugar nucleotide donor guanosine 5′‐diphosphate‐L‐fucose (GDP‐Fuc). Here, we describe a protocol for applying a one‐pot three‐enzyme system in synthesizing structurally defined fucose‐containing oligosaccharides from free L‐fucose. In this system, GDP‐Fuc is generated from L‐fucose, adenosine 5′‐triphosphate (ATP), and guanosine 5′‐triphosphate (GTP) by a bifunctional L‐fucokinase/GDP‐fucose pyrophosphorylase (FKP). An inorganic pyrophosphatase (PpA) is used to degrade the by‐product pyrophosphate (PPi) to drive the reaction towards the formation of GDP‐Fuc. In situ generated GDP‐Fuc is then used by a suitable fucosyltransferase for the formation of fucosides. The three‐enzyme reactions are carried out in one pot without the need for high‐cost sugar nucleotide or isolation of intermediates. The time for the synthesis is 4 to 24 hr. Purification and characterization of products can be completed in 2 to 3 days. Curr. Protoc. Chem. Biol. 4:233‐247 © 2012 by John Wiley & Sons, Inc.
Recent Progress in Redox Flow Battery Research and Development
Authors: Wang Wei , Luo Qingtao , Li Bin , Wei Xiaoliang , Li Liyu , Yang Zhenguo
Published: September 2012

With the increasing need to seamlessly integrate renewable energy with the current electricity grid, which itself is evolving into a more intelligent, efficient, and capable electrical power system, it is envisioned that energy‐storage systems will play a more prominent role in bridging the gap between current technology and a clean sustainable future in grid reliability and utilization. Redox flow battery technology is a leading approach in providing a well‐balanced solution for current challenges. Here, recent progress in the research and development of redox flow battery technology, including cell‐level components of electrolytes, electrodes, and membranes, is reviewed. The focus is on new redox chemistries for both aqueous and non‐aqueous systems.
Microribbon‐Like Elastomers for Fabricating Macroporous and Highly Flexible Scaffolds that Support Cell Proliferation in 3D
Authors: Han Li‐Hsin , Yu Stephanie , Wang Tianyi , Behn Anthony W. , Yang Fan
Published: September 2012

Hydrogel‐based scaffolds are widely used for culturing cells in three dimensions due to their tissue‐like water content and tunable biochemical and physical properties. Most conventional hydrogels lack the macroporosity desirable for efficient cell proliferation and migration and have limited flexibility when subject to mechanical load. Here microribbon‐like elastomers that, when photocrosslinked, can form macroporous and highly flexible scaffolds that support cell proliferation in 3D are developed. These microribbons are produced by wet‐spinning gelatin solution into microfibers, followed by drying in acetone, which causes asymmetrical collapse of microfibers to form microribbon‐like structures. Gelatin microribbons are then modified using methacrylate anhydride to allow further photocrosslinking into 3D scaffolds. The macroporosity and mechanical properties of the microribbon‐based scaffold may be tuned by varying wet‐spinning rate, drying temperature, choice of drying agent, level of glutaraldehyde crosslinking, and microribbon density. When encapsulated in the microribbon‐based scaffold, human adipose‐derived stromal cells proliferated up to 30‐fold within 3 weeks. Furthermore, microribbons‐based scaffold demonstrate great flexibility and can sustain up to 90% strain and 3 MPa stress without failing. The unique mechanical properties of microribbon‐based scaffolds make them promising tools for engineering shock‐absorbing tissues such as cartilage and intervertebral discs.
Heterogeneous Nucleation Promotes Carrier Transport in Solution‐Processed Organic Field‐Effect Transistors
Authors: Li Ruipeng , Khan Hadayat Ullah , Payne Marcia M. , Smilgies Detlef‐M. , Anthony John E. , Amassian Aram
Published: September 2012

A new way to investigate and control the growth of solution‐cast thin films is presented. The combination of in situ quartz crystal microbalance measurements with dissipation capabilities (QCM‐D) and in situ grazing‐incidence wide‐angle X‐ray scattering (GIWAXS) in an environmental chamber provides unique quantitative insights into the time‐evolution of the concentration of the solution, the onset of nucleation, and the mode of growth of the organic semiconductor under varied drying conditions. It is demonstrated that careful control over the kinetics of solution drying enhances carrier transport significantly by promoting phase transformation predominantly via heterogeneous nucleation and sustained surface growth of a highly lamellar structure at the solid‐liquid interface at the expense of homogeneous nucleation.
Influence of the Injection‐Molding Parameters on the Cellular Structure and Thermo‐Mechanical Properties of Ethylene‐Propylene Block Copolymer Foams
Authors: Gómez‐gómez J. F. , Arencón D. , Sánchez‐soto M. A. , Martínez A. B.
Published: September 2012

Microcellular injection‐molding technology is capable of producing lightweight polymeric products. The foam morphology is determined by the injection‐molding parameters, and it has been observed that depending on the parameter variations, the cell structure may exhibit substantial morphological differences through the entire section along the melt flow direction of the injected part. The effects of varying injection‐molding parameters on foam morphology and thermal mechanical properties of a multiphase ethylene‐propylene block copolymer (EPBC) were tested on 5‐mm plaque specimens using a constant temperature profile. It has been found that injection speed does not have a significant effect on the thermal‐mechanical properties of the foam, whereas shot volume and mold temperature do have a significant influence. Low shot volume produces uniform density cellular structures and larger cores, whereas lower mold temperatures help maintain small cell sizes. Furthermore, the effect of the copolymer's crystalline phase on foam morphology has been observed. This study identifies the achievable foam morphologies and the thermal‐mechanical performance of cellular molded EPBC parts. © 2012 Wiley Periodicals, Inc. Adv Polym Techn 32: E692–E704, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21311
Synthesis and Antitubercular Activity Evaluation of Novel Unsymmetrical Cyclohexane‐1,2‐diamine Derivatives
Authors: Beena  , Joshi Seema , Kumar Nitin , Kidwai Saqib , Singh Ramandeep , Rawat Diwan S.
Published: September 2012

A library of unsymmetrical cyclohexane‐1,2‐diamine derivatives were synthesized and evaluated for their activity against Mycobacterium tuberculosis H37Rv in vitro. Out of the 46 compounds synthesized, eight compounds (11h, 13a, 13e, 13f, 14a, 14c, 14d, and 15d) were found to be active at or below 6.25 µM concentration, with negligible toxicity to human red blood cells at a concentration much higher than the MIC99. Compound 13a was the best active compound showing inhibition at 3.125–6.25 µM, and was found to be non‐hemolytic up to 500 µg/mL concentration.
Observability Analysis and Improved Zero‐Speed Position Observer Design of Synchronous Motor with Experimental Results
Authors: Zaltni D. , Ghanes M.
Published: September 2012

This paper deals with the permanent magnet synchronous motor (PMSM) observability analysis for sensorless control design. The problem of loss of observability at low frequency range is always recognized in experimental settings. Nevertheless, there are no sufficient theoretical observability analyses for the PMSM. In the literature, only the sufficient observability condition has been presented. Therefore, the current work is aimed especially towords the necessary observability condition analysis. Furthermore, improved zero‐speed observation is presented here for a surface PMSM (SPMSM) to overcome position observability problems at zero‐speed which is an unobservable state point. The proposed observer based on higher order sliding mode (HOSM) is designed in order to ensure robustness against disturbances and to avoid the chattering phenomenon which is inherent in standard first order sliding modes. The stability and finite time convergence of the developed observer are studied and discussed. Experimental results are carried out to illustrate the effectiveness and robustness of the proposed observer.
Theoretische Untersuchungen zum Stofftransport in turbulenter Rohrströmung zu Ringelektroden
Authors: Dreesen E. W. , Vielstich W.
Published: September 2012

Die Differentialgleichung der konvektiven Diffusion für den Stofftransport zu Ringelektroden in turbulenter Rohrströmung wird durch Transformationen in eine Form gebracht, die es erlaubt, den Stofftransport durch Einführung von sogenannten normierten Nusseltzahlen Nu+ explizit unabhängig von der Reynoldszahl (Re), der Prandtlzahl (Pr), der Ausdehnung der Elektrode in Strömungsrichtung und dem Rohrdurchmesser darzustellen.

Es werden Kriterien dafür angegeben, wann die übliche Darstellung des Stofftransports durch eine Beziehung der Art Nu ∼ Rea · Prb, zutrifft.
Nahordnung in Flüssigkeiten, IV LCAO‐MO‐Modellrechnungen zur Lösungsmittelabhängigkeit der 13C‐NMR‐Verschiebung
Authors: Schröer Wolffram
Published: September 2012

Bin LCAO‐MO‐Verfahren zur Berechnung von 13C‐NMR‐chemischen Verschiebungen wird angegeben. Die 13C‐Verschiebungen der Äthylenkohlenstoffatome verschiedener Äthylenderivate werden damit berechnet. Außerdem werden die NMR‐Verschiebungen von Acrylnitril bei Wechselwirkung mit einem H+ ‐ oder CN−‐Ion, die als Modell für ein polares Lösungsmittel dienen, abgeschätzt. Die experimentellen Lösungsmittelverschiebungen von Acrylnitril in Mischungen von CCl4 und Hexamethylphosphorsäure‐Triamid entsprechen diesen Berechnungen und zeigen somit Veränderungen der Elektronenstruktur an, wie sie entsprechend der chemischen Reaktivität α,β‐ungesättigter Karbonyl‐Verbindungen erwartet werden.
The Influence of Chemical Exchange on NMR Spin Lattice Relaxation
Authors: Strehlow H. , Frahm J.
Published: September 2012

A method is presented for the determination of chemical rate constants from spin‐lattice relaxation times T1. The exchange rate of water molecules between the inner‐hydration sphere of nickel ions and the bulk has thus been obtained in Ni(NO3)2 solutions. The results indicate a nitrate inner‐sphere complex with a stability constant of about 0.2 M−1. The ratio of the Ni2+ ion‐water proton distances in the first and second hydration layers is estimated. A combined T1 — T2 technique is proposed which improves the accuracy of the measurement of fast chemical reactions.
Messung der Stoßfrequenz in Gasentladungen verschiedener mehratomiger Gase
Authors: Janzen G. , Staib W. , Kruppa G. , Schücker U. , Suhr H.
Published: September 2012

Die Stoßfrequenzen in den Plasmen von Ar, He, H2, CO, O2, H2O, CO2, NH3, CH4, CH3OH, CH3COCH3 wurden bei verschiedenen Werten von Entladungsstrom und Druck über die Resonanzverbreitung eines Mikrowellen‐Hohlraumresonators gemessen. Aus Längsfeldstärke und Elektronendichte berechnete Stoßfrequenzwerte stimmen gut mit diesen Werten überein.
Die Reaktionen von atomarem Wasserstoff mit Cyclohexen, Cyclohexadien‐1,3 und Benzol
Authors: Hoyermann K. , Preuss A. W. , Gg. Wagner H.
Published: September 2012

Die Reaktionen von atomarem Wasserstoff mit cyclischen C6‐Kohlenwasserstoffen (Cyclohexen, Cyclohexadien‐1,3, Benzol) wurden in einem isothermen Strömungssystem (gekoppelt an ESR, Massenspektrometer, Gaschromatograph) bei Temperaturen von 296 ≤ T ≤ 493 K und Drücken von 1,9 ≤ p ≤ 14,7 Torr bei Unterschuß von atomarem Wasserstoff untersucht.

Die Messungen der Geschwindigkeitskonstanten der Reaktionen ergaben:

Für Drücke p > 5 Torr und hohe Überschußverhältnisse ([Reaktand]0/[H]0) bleibt das Ringsystem auch bei Ablauf der Folgereaktionen hauptsächlich erhalten. (Hauptreaktionsprodukte für Cyclohexen: Cyclohexan; für Cyclohexadien‐1,3: Cyclohexen, Cyclohexan; für Benzol: Cyclohexen; Cyclohexadiene, Cyclohexan). Die Reaktionsmechanismen werden diskutiert.
Complex Formation in Reactive and Inelastic Scattering: Statistical Adiabatic Channel Model of Unimolecular Processes III
Authors: Quack M. , Troe J.
Published: September 2012

The statistical adiabatic channel model developed previously [25] for unimolecular dissociation reactions is extended to describe bimolecular collisions proceeding via a strongly bound intermediate complex. As examples three cases are considered, in which the intermediate complex corresponds to a known stable molecule: O + O2 → O3*, O + NO → NO2* and Cl + NO → ClNO*. Using known molecular properties and the experimental high pressure recombination rate constants, the specific dissociation rate constants k(E,J), state to state inelastic scattering cross sections σ(v,j → v',j') and center of mass translational energy distributions are calculated with the same simple potential model. Rate constants kvv, for vibrational relaxation are computed and found to be in good agreement with experimental results available for the O + O2 vibrational relaxation. The dependence of cross sections and final state distributions as a function of initial state is illustrated in some detail. Even within the statistical model, there is found to be a marked memory of initial conditions. The range of validity of statistical models is discussed.
Thermal Transpiration in a Dissociating Gas
Authors: Wright P. G.
Published: September 2012

By use of the dusty‐gas model, an analysis is given of the gradient of pressure set up in the steady state in a dissociating gas in local chemical equilibrium in a gradient of temperature in a porous medium (or in a capillary tube). For a dissociating gas, though not for an isomerising gas, the gradient of pressure thereby induced can be appreciably greater than for a non‐reacting gas (though the enhancement is less marked than the corresponding enhancement of the thermal conductivity). The enhancement remains appreciable even for a gas in which there is only a small proportion of the associated species; and for a porous medium with very small pores the steady state could in consequence be one with (p−1 δp/δz)/(T−1 δT/δz) detectably greater than the conventional 0.5000.

It is shown in passing that a result previously established for a dusty gas at uniform temperature, that the Stefan‐Maxwell equations for diffusion can be compounded with relevant equations for viscous contributions to the resultant fluxes, to give a set of equations of the unaugmented Stefan‐Maxwell form but with modified values for coefficients appearing in them, also holds for a dusty gas in a gradient of temperature.
Der Dampfdruck‐Isotopie‐Effekt von deuterierten Neopentanen
Authors: Höpfner A. , Parekh N. , Hörner Ch. , Abdel‐Hamid A.
Published: September 2012

Der Dampfdruck von Neopentan und die Dampfdruck‐Isotopie‐Effekte von 6 deuterierten Neopentanen (C(CD3)4, C(CH3)(CD3)3, C(CH3)2(CD3)2, C(CH2D)4, C(CH3)3(CD3) und C(CH3)3(CH2D)) im Temperaturbereich zwischen ‐60 und +20°C werden mitgeteilt. Der Effekt ist in allen Fällen wie erwartet invers. Die beobachteten Tripelpunkte liegen zwischen ‐16,64 (Neopentan) und ‐18,66°C (Neopentan‐D12). Die beobachteten Dampfdrücke und die aus ihnen abgeschätzten Verdampfungsenthalpien werden mit Literatur‐Daten verglichen.
Homogeneous Particle Growth from the Reaction of SO2 with n‐Butane
Authors: Jordan H. , Penzhorn R.‐D.
Published: September 2012

Photolysis of SO2 with n‐butane results in several products wich can condense to particles. The particle mass concentration (pmc) and the rate of product formation were measured in this system during and after photolysis. After a certain irradiation time a maximum pmc is reached. The hight of the pmc maximum is a function of the photochemical reaction rate. Based on simple model considerations, we show that the photochemically produced aerosols are lost mainly by sedimentation, are monodisperse and that the particle size is relatively insensitive to the photochemical reaction rate.
Kinetics of Redox Couples at Solid Electrodes: II ‐ Ferro‐Ferricyanide System in Nearly Neutral Media on Rotating Disk Electrodes of Polycristalline Spinel Manganites CuxMn3‐xO4, with x = 1.2
Authors: Beley M. , Brenet J. , Chartier P.
Published: September 2012

Die Kinetik der Durchtrittsreaktion des Redox‐Systems Fe(CN)64‐/Fe(CN)63‐ ist mit einer aus CuxMn3‐xO4 (x = 1,2) bestehenden rotierenden Scheibenelektrode untersucht worden. Der kathodische Strom wird teilweise inhibiert. Es ergeben sich Durchtrittsfaktoren α = β = 0,50. Die scheinbare Standardreaktionsgeschwindigkeitskonstante ist in der Größenordnung von (3 ± 2) · 10−3 cm s−1. Nur mit äquimolaren Lösungen wird eine Reaktionsordnung 1 beobachtet, und der Einfluß der Fe(CN)63‐‐Ionen auf die Oxydation der Fe(CN)64‐‐Ionen wird nahegelegt.
High‐Temperature Viscometer for Fluid Liquids Part I: On‐line Computer‐facilitated Torsion Pendulum
Authors: Ohta T. , Borgen O. , Brockner W. , Fremstad D. , Grjotheim K. , Tørklep K. , Øye H. A.
Published: September 2012

An oscillation viscometer, interfaced to an on‐line minicomputer for measurement of the viscosity of low‐viscous hygroscopic melts up to 1200°C, is described. The paper gives a discussion of changes in experimental technique facilitated by use of the computer, and the resulting improvements in the viscometer performance.
High‐Temperature Viscometer for Fluid Liquids Part II: Viscosities of the Alkali Chlorides
Authors: Brockner W. , Grjotheim K. , Ohta T. , Øye H. A.
Published: September 2012

In an effort to obtain better standard values for melt viscosities, the viscosities of the molten alkali chlorides have been re‐determined as a function of the temperature by the method of the oscillating sphere. The relationship between viscosity and temperature can be represented satisfactorily by an Arrhenius equation giving an activation energy for viscous flow. The viscosities obtained are discussed in the light of recent literature values.
Zur Adsorption von Xenon und Krypton an verschiedenen Oberflächen
Authors: Wischlitzki Dieter , Ahrens‐Botzong Rudolf , Hess Peter , Schäfer Klaus
Published: September 2012

Adsorptionsisothermen von Xenon und Krypton an einem aufgedampften Gold‐ und von Xenon an einem aufgedampften Platinfilm wurden im Bereich von 10−9 bis 10−2 Torr bestimmt. Die verschiedenen Temperaturen der Meßraumwände führen zu einem grundsätzlichen gaskinetischen Auswertungsproblem. Aus rasterelektronenmikroskopischen Untersuchungen ließ sich die Filmrauhigkeit abschätzen. Die Oberflächenkonzentration der Monoschicht wurde aus einer Stufe in den Xenon‐ bzw. einem Knick in den Kryptonisothermen bestimmt. Im Einklang damit stehen Isothermen‐ und LEED‐Ergebnisse anderer Autoren an verschiedenen Metallen und Graphit. Xenon und Krypton bilden dichtgepackte Adsorbatschichten ähnlich den (111)‐Flächen der kondensierten Gase bei sehr kleinen Gleichgewichtsdrücken, verglichen mit den Sättigungsdampfdrücken. Aus dem Verhältnis beider Drücke läßt sich die Adsorptionswärme im Bereich der Monoschicht abschätzen. Die Übereinstimmung mit den isosteren Adsorptionswärmen ist bemerkenswert. An einigen Beispielen wird gezeigt, wie zu‐nehmende Oberflächenheterogenität die Ausbildung einer kondensationsartigen Isothermenstufe verhindert. Obwohl der Informationsgehalt einer Isothermen begrenzt ist, stellt sie eine wertvolle Ergänzung modernerer Untersuchungsmethoden dar.
Molekülstruktur von Allenen und Ketenen III [1] Circulardichroismusspektroskopische, absorptionsspektroskopische und CNDO/S‐Untersuchungen an Alkylallencarbonsäuren
Authors: Runge W. , Kosbahn W. , Winkler J.
Published: September 2012

Energiearme angeregte Singulettzustände von Alkylallencarbonsäuren und ihrer Anionen sowie allgemein der Substituenteneffekt der Carboxylgruppe auf Grundzustandseigenschaften des Allensystems werden mit Hilfe von Circulardichroismusspektroskopie, Absorptionsspektroskopie und CNDO/S‐Rechnungen untersucht.

Die Circulardichroismusspektren zeigen, daß den intensiven ersten π→π*‐Übergängen der Säuren bzw. ihrer Anionen drei schwache Übergänge vorgelagert sind, die in Form nur einer Absorptionsbande auftreten. Bezogen auf die Butadien‐(2,3)‐säure (“Allencarbonsäure”) und ihres Anions sind es S(A) angeregte Zustände, die durch π→π*‐Übergänge und π→π*‐bzw. π→π*‐Anregungen entstehen. Die Untersuchungen der Grundzustandseigenschaften der Systeme beziehen sich vor allem auf die Elektronendichteverteilung sowie die mesomeren Wechselwirkungen der Carboxylgruppe mit dem Allengerüst.
Lumineszenz von [Co(CN)6]3‐, [Rh(CN)6]3‐, [Ir(CN)6]3‐ mit verschiedenen Gegenionen
Authors: Wölpl A. , Oelkrug D.
Published: September 2012

Die Lumineszenzspektren, ‐abklingzeiten τ und ‐quantenausbeuten η der Hexacyanometallate Am[M(CN)6]n mit M = Co(III), Rh(III), Ir(III) und A = K+, Cd2+, In3+ wurden in Abhängigkeit von der Temperatur untersucht. In allen Fällen wird die Lumineszenz dem Übergang 3T1g τ 1A1g zugeordnet. Die Energie der Bandenmaxima wächst in der Reihenfolge Co(III) < Rh(III) < Ir(III) (14100, 19600, 23400 cm−1 für die K‐Verbindungen), sie wird aber auch durch die Komplexgegenionen beeinflußt und liegt in den In‐Verbindungen immer um etwa 1000–1500 cm−1 höher. In der gleichen Reihenfolge wächst die Halbwertsbreite der Lumineszenzbanden und ihre Stokessche Verschiebung, τ und η nehmen in dieser Reihenfolge ab. Die beiden letzten Größen hängen wiederum stark vom Gegenion bzw. vom Kristallgitter ab und sind in den Indiumverbindungen besonders hoch (τ = 2,8 msec, τ = 0,2 bis 0,3 in InCo(CN)6 gegenüber τ = 0,68 msec, τ = 0,05 in K3Co(CN)6 ‐ τ = 0,4 msec, τ = 0,05 in InRh(CN)6 gegenüber τ = 0,15 msec, τ = 0,01 in K3Rh(CN)6; jeweils bei 77 K). In allen Fällen wird die Lumineszenz schon weit unterhalb von Zimmertemperatur thermisch gelöscht. Die Löschung wird mit einer großen Verschiebung der Potentialflächen von Grund‐ und angeregtem Zustand erklärt und im Rahmen des Modells stark gekoppelter Oszillatoren interpretiert.
Kinetik der Diffusion und Desorption bei der nicht‐isothermen Gasentbindung aus Aktivkohlen
Authors: Feistel P. P. , Jüntgen H. , Peters W.
Published: September 2012

Eine Regeneration beladener Adsorbentien kann durch Druckerniedrigung oder Temperaturerhöhung erfolgen. Die dabei ablaufenden Diffusions‐ und Desorptionsvorgänge werden am Beispiel der Adsorptive Argon, Krypton und Xenon und dreier Aktivkohlen verschiedener, aber definierter Hohlraumstruktur untersucht. Die mittels nicht‐isothermer Temperaturführung gemessenen Diffusionsparameter stimmen gut mit entsprechenden Ergebnissen aus isothermen Messungen überein. Das zur Auswertung erforderliche Kennlinienfeld wird mitgeteilt. Der Übergang von aktivierter Spaltdiffusion zu aktivierter Desorption findet bei um so kleineren Beladungen statt, je kleiner das Adsorptivmolekül und je weitporiger die Aktivkohle ist. Im Bereich der Desorption sind Aktivierungsenergien und Frequenzfaktoren statistisch verteilt. Die Beladungsdichte ist eine Exponential‐Verteilung. Die Auswertung der mit starkem Tailing versehenen Desorptionskurven wird ausführlich diskutiert. Das für heterogene Oberflächen entwickelte mathematische Modell erfaßt das Tailing und die Verlagerung des Peakmaximums mit abnehmender Beladung zu höheren Temperaturen hin.
Simulation Study of the Crystal Surface during Dissolution
Authors: Horsák I. , Skřivánek J.
Published: September 2012

The process of crystal dissolution is simulated on a computer by the Monte‐Carlo method as a stochastic process. The transition probability of a particle from the crystal surface into the liquid phase is defined as dependent on the surrounding surface structure. The change of the effective crystal surface with time is studied, temperature being a parameter.
Reaktion von O(3P)‐Atomen mit Äthylacetylen
Authors: Herbrechtsmeier P. , Gg. Wagner H.
Published: September 2012

Die Reaktion von Sauerstoffatomen mit Äthylacetylen wurde in einem isothermen Strömungssystem bei Temperaturen von 290–357 K und Drücken von 4–40 Torr untersucht. Die stabilen Reaktionsprodukte (CO, C3H6 CH3C = CH, C2H4, C2H2, C2H6, CH4, Buten‐1, Butan, Hexen‐3, C3H8) wurden mit dem Gaschromatographen bzw. mit dem Massenspektrometer bestimmt. Für die Geschwindigkeitskonstante der Primärreaktion wurde gefunden:

Die Meßergebnisse deuten darauf hin, daß als ein Hauptkanal der Primärschritt O + C2H5–C = CH → CO + CH3CH3CH: abläuft.
HO2 Formation in Shock Heated HNO3 ‐NO2 Mixtures
Authors: Glänzer K. , Troe J.
Published: September 2012

HNO3 has been pyrolyzed in shock waves in the presence of NO2. The formation of HO2 in the reaction HO + NO2 → HO2 + NO has been monitored by the UV absorption. From the yields and lifetimes of HO2, a rate constant (4.5 ± 1) · 1012 cm3 mol−3 s−1 of the reaction HO2 + NO → HO + NO2 has been derived in the temperature range 1350–1700 K.
Unimolecular Processes IV: Product State Distributions after Dissociation
Authors: Quack M. , Troe J.
Published: September 2012

The statistical adiabatic channel model is used to calculate the distribution of internal states and center of mass translational energies of fragments in unimolecular dissociation. The reactions ClNO → Cl + NO and NO2 → NO + O are considered as examples. The influence of molecular parameters and dynamical constraints is illustrated. Mechanisms providing randomness in photodissociation and unimolecular decomposition are discussed as well as the relation between dissociation rates and statistical scattering. The statistical calculations for NO2 decomposition are in good agreement with the experimental center of mass translational energy distributions from photofragment spectroscopy.
Charge Distribution and Structure of Complexes MeIGaCl4, MeIGa2Cl7, and KAl2Br7 (MeI = Na⊕, K⊕, Rb⊕, Cs⊕, Ga⊕). An NQR Investigation (35Cl, 69Ga, 81Br)
Authors: Deeg Timm , Weiss Alarich
Published: September 2012

35Cl and 69GaIII NQR frequencies are reported for MeGa2IIICl7 (Me = Na, K, Rb, Ga1) together with the 35Cl NQR frequencies for MeGaIIICl4 (Me = Na, K, Rb, Cs, Ga1), and the 81Br and 79Br NQR frequencies for KAl2Br7. Most of the corresponding 37Cl and 71GaIII resonances in MeGa2Cl7 are reported too. With the exception of RbGaCl4 and CsGaCl4 all NQR investigations were done as a function of the temperature.

The complexes MeGa2Cl7 show seven 35Cl and two 69Ga NQR lines each. From the 35Cl NQR spectra it is concluded that the ion (Ga2Cl7)⊕ has a bridged structure analogous to the ions (Me2X7)⊕ in KAl2Br7 and Te4(Al2Cl7)2. Six of the 35Cl resonances are assigned to crystallographically inequivalent terminal Cl atoms, the seventh 35Cl resonance showing a low frequency shift is assigned to the bridging Cl atom. The charge distribution of the ion (Ga2Cl7)⊕ was estimated within the frame of the Townes‐Dailey theory. The selfconsistency of the calculations is satisfactory.

For two compounds, CsCl · xGaCl3 and RbCl · yGaCl3, investigated by NQR spectroscopy, no definite structural proposals are available up to now.

From the 81Br NQR spectrum of KAl2Br7 no assignment either to terminal Br atoms or to the bridging Br atom is possible. A small degree of (p → d)π character involving the terminal AlBr bonds is considered a conceivable explanation.

From the 35Cl NQR spectra in KGaCl4 and GaGaCl4 polymorphism is found. The transformation to the high temperature phase in either complex is accompanied with a lowering of symmetry of the GaCl4 tetrahedra and an increase of the crystal field splitting. This finding is in qualitative agreement with a decrease in volume on changing to the high temperature phase.
Über die Transporte binärer Nichtelektrolytgemische in isothermen asymmetrischen Membransystemen
Authors: Stormberg H.‐P.
Published: September 2012

Die Transporteigenschaften asymmetrischer Membranen in isothermen Systemen ohne Druckgradient werden an binären Nichtelektrolytgemischen untersucht. Der durch die asymmetrische Struktur der Membran hervorgerufene Effekt wird im System Benzol‐Methanol genauer erforscht. Eine qualitative Interpretation dieses Effekts kann gegeben werden, indem eine Konzentrationsabhängigkeit der Reibungskoeffizienten eingeführt wird. Die daraus resultierenden pseudolinearen Koeffizienten sind dann Integrale, in denen der Konzentrationsverlauf enthalten ist.
The Quantum Yield of Photolysis of Water on TiO2 Electrodes
Authors: Ohnishi T. , Nakato Y. , Tsubomura H.
Published: September 2012

The quantum yield of the photo‐currents in the electrochemical cell, n‐TiO2/electrolyte/Pt, was measured under monochromatic illumination of TiO2 at various electrode potentials. It has been found that the quantum yield is very small (10−3) in case where no voltage was applied from outside, getting smaller with illumination intensity. The results of measurements of the quantum yield, together with those of the electrode potential of TiO2, at various conditions are explained from the energy level scheme of the semi‐conductor and redox potentials in the solution. The very small efficiency of this photo‐galvanic cell as a light energy converter has been attributed to the small difference between the flat‐band potential of the TiO2 electrode and the reduction potential of H+.
Periodic Temperature Changes and Crystal Ripening
Authors: Horsák I. , Vacek V. , Žáček S.
Published: September 2012

The influence of periodic temperature changes on the rate of crystal ripening is investigated. The study is based on a simple model of crystal growth and dissolution kinetics. In the system of two different crystals, it was found that the ripening process is intensified by temperature oscillation. This fact is in qualitative agreement with observed data.
Reaktionen des Butadiins II. Die Reaktion mit Sauerstoffatomen
Authors: Homann K. H. , Schwanebeck W. , Warnatz J.
Published: September 2012

Die Reaktion von Sauerstoffatomen mit Butadiin (C4H2) wurde in einem isothermen Strömungssystem im Temperaturbereich 297–343 K und bei Drücken um 3 mbar untersucht. Zur Analyse diente ein Quadrupol‐Massenspektrometer, das mit dem Reaktionssystem durch eine Molekularstrahlanordnung verbunden war. Die Reaktion O + C4H2verläuft nach 2. Ordnung mit einer Geschwindigkeitskonstantenentsprechend einer Aktivierungsenergie von 10,2 kJ mol−1. Die Reaktionsprodukte sind hauptsächlich CO, C2H2, C6H2, C4H4, C3H4, Polymeres und H‐Atome. Die Geschwindigkeitskonstante der getrennt gemessenen Reaktion O + C4H4beträgt bei Zimmertemperatur