The elasticity problem for a thick-walled cylinder containing a circumferential crack

The elasticity problem for a long hollow circular cylinder containing an axisymmetric circumferential crack subjected to general nonaxisymmetric external loads is considered. The problem is formulated in terms of a system of singular integral equations with the Fourier coefficients of the derivative of the crack surface displacement as density functions. The stress intensity factors and the crack opening displacement are calculated for a cylinder under uniform tension, bending by end couples, and self-equilibrating residual stresses

Transient thermal stress problem for a circumferentially cracked hollow cylinder

The transient thermal stress problem for a hollow elasticity cylinder containing an internal circumferential edge crack is considered. It is assumed that the problem is axisymmetric with regard to the crack geometry and the loading, and that the inertia effects are negligible. The problem is solved for a cylinder which is suddenly cooled from inside. First the transient temperature and stress distributions in an uncracked cylinder are calculated. By using the equal and opposite of this thermal stress as the crack surface traction in the isothermal cylinder the crack problem is then solved and the stress intensity factor is calculated. The numerical results are obtained as a function of the Fourier number tD/b(2) representing the time for various inner-to-outer radius ratios and relative crack depths, where D and b are respectively the coefficient of diffusivity and the outer radius of the cylinder

New Nurse Residency - An Evidence Based Approach

Nurse educators believe that their graduates are well-prepared for entry level positions in nursing. In the acute healthcare setting, new graduates are placed on virtually every type of nursing unit, including critical care. Employers have developed formal orientations to familiarize new graduate nurses new with the institution and its policies and procedures and to teach the things employers believe new RNs need to know but do not, either because they were never taught the material or they have not retained it. The purposes of this project were to (a) examine the evidence relative to a disconnect between nursing education and nursing practice, (b) design a formal residency program for new graduates based on the evidence, and (c) implement and evaluate the residency program. Based on the evidence, a 16-week new nurse residency was developed in which Residents were each assigned both a Preceptor and Mentor to assist their progress. Weekly educational offerings were targeted at specific competency deficits identified by Residents, Preceptors and Mentors at the beginning of the residency program. Seven out of the original 10 Residents completed the Residency. Pre-residency, the Residents were very confident of their clinical skills and abilities and this was unchanged post-residency. The Preceptors and Mentors were much less confident of the clinical skills and abilities of the Residents pre-residency. Post-residency, the confidence level of the Preceptors and Mentors was improved, but significantly so only for the Mentors. It is imperative that nursing administrators be aware of the discrepancy between the confidence new nurses have in their own skills and the perceptions of the nurses who work side by side with them on a daily basis. Residencies for new graduate nurses are costly. Nursing administrators must make the determination if the benefits outweigh the costs. They may find the results of not having a residency are far more costly

Efeito de uma infusão de Stevia Rebaudiana Bertoni na desmineralização do esmalte e na formação do biofilme dentário – um estudo in situ

A redução do consumo de açúcar e sua substituição por adoçantes não calóricos é considerada uma abordagem útil para a prevenção da cárie, pois é de extrema importância o uso de substâncias que possam modificar a cariogenicidade desse biofilme. Estudos mostram que a planta da espécie Stevia rebaudiana pode modificar a cariogenicidade do biofilme, mas o mecanismo não é bem compreendido. O objetivo deste estudo in situ foi avaliar o efeito de uma infusão de Stevia Rebaudiana Bertoni na desmineralização do esmalte e na formação do biofilme dental. Em um estudo cruzado, onze voluntários adultos utilizaram um dispositivo intrabucal palatino contendo 4 blocos de esmalte dental bovino, em 3 fases de 7 dias cada. Sobre esses blocos de esmalte foram gotejadas em horários pré-estabelecidos 2 soluções: sacarose 20% na frequência de 8X/dia e outra solução, de tratamento na frequência de 2X/dia, podendo ser uma solução Stevia 5%, Clorexidina 0,12% (CHX) ou Cloreto de Sódio 0,9% (NaCl). Entre cada fase experimental foi adotada 1 semana de wash-out. Ao final de cada fase experimental, o biofilme formado sobre os blocos dentais foi coletado e analisado em relação a sua composição microbiológica [contagem de Streptococcus mutans (SM), Lactobacillus spp. (LB), Candida albicans (CA) e microorganismos totais (MT) (UFC/mg)], sua composição bioquímica em termos de quantificação de Polissacarídeos Extracelulares solúvel (PECS) e insolúvel (PECI)(μg/mg) e avaliado qualitativamente por Microscopia Eletrônica de Varredura. O percentual de perda de dureza superficial (%PDS) dos blocos de esmalte também foi avaliado. Todos os desfechos foram analisados através de ANOVA a um nível de 5% de significância. Não foram encontradas diferenças entre Stevia, CHX e NaCl para PECS (13,7a ±14,9; 15,1a ±15; 13,2a ±10,8; respectivamente), PECI (28,6a ±27,3; 22a ±21,1; 24,8a ±17,4; respectivamente), SM (2,8x104a ±7x104; 4,1x103a ±1,2x104; 7,2x103a ±1,8x104; respectivamente), LB (8x105a ±1,2x106; 3,3x105a ±7,3x105; 8,6x105a ±1,7x106; respectivamente), CA (8,9x105a ±2x106; 1,9x104a ±4,3x104; 1,9x105a ±2,6x105; respectivamente) e TM (8,1x107a ±1,5x108; 3,9x107a ±6,6x107; 1,2x107a ±1,7x107; respectivamente). O %PDS encontrado na presença de CHX foi estatisticamente menor que o NaCl. O %PDS na presença de Stevia foi considerado intermediário entre ambos (-7,4a ±12; -33,4b ±29,5; -22,1ab ±28,8; respectivamente). As evidências observadas no presente estudo, sugerem que a utilização de Stevia em situação de alto desafio cariogênico tem pouco efeito na modificação da cariogenicidade do biofilme e na progressão da lesão cariosaThe reduction of sugar consumption and its substitution by non-caloric sweeteners is considered a useful approach for the prevention of caries, since it is extremely important to use substances that can modify the cariogenicity of this biofilm. Studies have shown that Stevia rebaudiana can modify the cariogenicity of the biofilm, but the mechanism is not well understood. The objective of this in situ study was to evaluate the effect of Stevia rebaudiana Bertoni infusion on enamel demineralization and on dental biofilm formation. In a cross-over desing, eleven adult volunteers used a palatal intraoral device containing 4 slabs of bovine enamel, in 3 phases of 7 days each. On these enamel slabs were dripped, at pre-set times, 2 solutions: sucrose 20% at the frequency of 8X/day and another solution, at a frequency of 2X/day, which was Stevia infusion 5%, 0,12% Chlorhexidine (CHX) or 0,9% Sodium Chloride (NaCl). Between each experimental phase was adopted 1 week of wash-out. At the end of each experimental phase, the biofilm formed on the slabs was collected and analyzed for microbiological composition [counts of Streptococcus mutans (SM), Lactobacillus spp. (LB), Candida albicans (CA) and total microorganisms (TM) (CFU/mg)], biochemical composition in terms of quantification of extracellular soluble (SEPS) and insoluble polysaccharides (IEPS)(μg/mg) and qualitatively assessed by Scanning Electron Microscopy. Percentage of surface hardness loss (%SHL) was evaluated on enamel slabs. All the outcomes were analyzed by ANOVA at a level of 5% of significance. No differences were found among Stevia, CHX and NaCl for SEPS (13,7a ±14,9; 15,1a ±15; 13,2a ±10,8; respectively), IEPS (28,6a ±27,3; 22a ±21,1; 24,8a ±17,4; respectively), SM (2,8x104 a ±7x104; 4,1x103 a ±1,2x104; 7,2x103 a ±1,8x104; respectively), LB (8x105a ±1,2x106; 3,3x105a ±7,3x105; 8,6x105a ±1,7x106; respectively), CA (8,9x105a ±2x106; 1,9x104a ±4,3x104; 1,9x105a ±2,6x105; respectively) and TM (8,1x107a ±1,5x108; 3,9x107a ±6,6x107; 1,2x107a ±1,7x107; respectively). The %SHL found in the presence of CHX was statistically lower than NaCl. The %SHL in the presence of Stevia was considered intermediate between them (-7,4a ±12; -33,4b ±29,5; -22,1ab ±28,8; respectively). The evidences observed in the present study suggest that the use of Stevia in situations of high cariogenic challenge has little effect on the modification of biofilm cariogenicity and on the progression of the carious lesio

Rules from Words: A Dynamic Neural Basis for a Lawful Linguistic Process

Listeners show a reliable bias towards interpreting speech sounds in a way that conforms to linguistic restrictions (phonotactic constraints) on the permissible patterning of speech sounds in a language. This perceptual bias may enforce and strengthen the systematicity that is the hallmark of phonological representation. Using Granger causality analysis of magnetic resonance imaging (MRI)- constrained magnetoencephalography (MEG) and electroencephalography (EEG) data, we tested the differential predictions of rule-based, frequency–based, and top-down lexical influence-driven explanations of processes that produce phonotactic biases in phoneme categorization. Consistent with the top-down lexical influence account, brain regions associated with the representation of words had a stronger influence on acoustic-phonetic regions in trials that led to the identification of phonotactically legal (versus illegal) word-initial consonant clusters. Regions associated with the application of linguistic rules had no such effect. Similarly, high frequency phoneme clusters failed to produce stronger feedforward influences by acoustic-phonetic regions on areas associated with higher linguistic representation. These results suggest that top-down lexical influences contribute to the systematicity of phonological representation

Prinzipien guten Unterrichts, Unterrichtsplanung und Lehrwerkanalyse

What makes a good textbook? What criteria can be used to analyse and evaluate textbooks? How can we recognise if the grammar section in a textbook is up-to-date, helpful and learner-oriented? How can authentic materials be transferred into didactically well-structured lessons? This paper discusses possible answers and presents both criteria for textbook analysis and important methods and principles for good teaching

Konzeption, Stand der Umsetzung und Weiterentwicklung von multimodalen Mobilitätsflatrates & -paketen

Diese Arbeit befasst sich detailliert mit multimodalen Mobilitätsflatrates und -paketen im Zusammenhang mit Mobility-as-a-Service (MaaS) und liefert eine ganzheitliche Gesamtschau zu diesem Forschungsgebiet. Dabei werden verschiedene wissenschaftliche als auch praktische Ansätze zur Konzeption aufgezeigt, woraus jedoch noch keine favorisierte Ausführung hervorgegangen ist. Dies hängt mit der Aktualität des Themas und den erst wenig umgesetzten Beispielen in der Praxis zusammen. Herausforderungen treten insbesondere im regulatorischen, wirtschaftlichen und im geringeren Umfang auch im technischen Kontext auf. Der wichtigste Aspekt bei der Konzeption ist die Wirtschaftlichkeit, weshalb es unabdingbar ist, die Nachfrage und die Angebotskonditionen sorgfältig zu ermitteln. Der ÖPNV stellt bei den Mobilitätspaketen das Rückgrat dar, der durch zusätzliche andere Verkehrsdienstleistungen erweitert wird. Multimodale Mobilitätsflatrates und -pakete verfügen über die Fähigkeit die verschiedenen Verkehrsdienstleistungen zu kombinieren und dabei teilweise eine einfachere, komfortablere, nachhaltigere und auch günstigere Mobilität zu realisieren als dies mit dem eigenen Auto möglich wäre. Verschiedene Ansätze zur zukünftigen Weiterentwicklung schließen diese wissenschaftliche Arbeit ab.:Abbildungsverzeichnis Tabellenverzeichnis Abkürzungsverzeichnis Glossar 1 Einführung 1.1 Hintergrund 1.2 Untersuchungsgegenstand und Forschungsfragen 1.3 Inhalt und Aufbau 2 Grundlagen und Klassifizierung 2.1 Definitionen 2.1.1 Bündelung 2.1.2 Flatrate 2.1.3 Mobility-as-a-Service (MaaS) 2.2 Literaturüberblick zur Klassifizierung von Mobilitätsflatrates und -paketen innerhalb von MaaS 3 Konzeption von multimodalen Mobilitätsflatrates und -paketen 3.1 Stakeholder und Ecosysteme 3.1.1 Stakeholder 3.1.2 Ecosysteme 3.2 Kontext und Anforderungen 3.2.1 Technischer Kontext 3.2.2 Regulatorischer und gesetzlicher Kontext 3.2.3 Wirtschaftlicher Kontext 3.3 Produktkonzeption 3.3.1 Allgemeines und Theorie 3.3.2 Produktgestaltung 3.3.3 Produktbündelung 3.3.4 Produktpreisbestimmung und Zahlungsbereitschaft 3.3.5 Produkterweiterung 3.4 Chancen und Risiken 3.5 Business Model Canvas 4 Stand der Umsetzung 4.1 Übersicht Anwendungsbeispiele 4.2 Whim 4.2.1 Geschäftsmodell 4.2.2 Produkt 4.2.3 Erfahrungen und Auswirkungen 4.2.4 Zukunft 4.3 UbiGo 4.3.1 Geschäftsmodell 4.3.2 Produkt 4.3.3 Erfahrungen und Auswirkungen 4.3.4 Zukunft 4.4 swa Mobil-Flat 4.4.1 Geschäftsmodell 4.4.2 Produkt 4.4.3 Erfahrungen und Auswirkungen 4.4.4 Zukunft 4.5 SBB Green Class 4.5.1 Geschäftsmodell 4.5.2 Produkt 4.5.3 Erfahrungen und Auswirkungen 4.5.4 Zukunft 4.6 Zusammenfassung der Praxisbeispiele 5 Weiterentwicklung und Ergänzung um branchennahe Dienstleistungen und Produkte 5.1 Weiterentwicklung 5.1.1 Roaming 5.1.2 Gamification und verhaltensbeeinflussende Maßnahmen 5.1.3 Ticketportfolio 5.1.4 Verhältnis Sharing und Owning 5.2 Ergänzung um branchennahe Dienstleistungen und Produkte 5.2.1 Versorgungs- und Immobilienbranche 5.2.2 Finanz- und Versicherungsbranche 5.2.3 Medienbranche 5.2.4 Lokale Gastronomie und lokaler Einzelhandel 5.2.5 Lieferservices und Logistik 6 Schlussbetrachtung 6.1 Zusammenfassung 6.2 Offene Forschungsfelder 6.3 Schlussfolgerungen und Ausblick Anhang LiteraturverzeichnisThis thesis examines multimodal mobility flat rates and packages in relation to Mobilityas-a-Service (MaaS) in detail and provides a holistic overview of this field of research. Various scientific as well as practical approaches to the concept are outlined but have not resulted in a favoured version yet. This is due to the recency of this topic and the fact that only a few cases have been implemented in practice. Challenges particularly arise in regulatory, economic and, to a lesser extent, technical contexts. The most important aspect in the design is economic efficiency. Therefore, it is essential to carefully determine demand and service conditions. Public transport is the backbone of mobility packages, which is complemented by other transport services. Multimodal mobility flat rates and packages have the capability to combine the various transport services and to realise a simpler, more comfortable, more sustainable and more affordable mobility compared to car-ownership. Finally, several approaches for future development complete this academic thesis.:Abbildungsverzeichnis Tabellenverzeichnis Abkürzungsverzeichnis Glossar 1 Einführung 1.1 Hintergrund 1.2 Untersuchungsgegenstand und Forschungsfragen 1.3 Inhalt und Aufbau 2 Grundlagen und Klassifizierung 2.1 Definitionen 2.1.1 Bündelung 2.1.2 Flatrate 2.1.3 Mobility-as-a-Service (MaaS) 2.2 Literaturüberblick zur Klassifizierung von Mobilitätsflatrates und -paketen innerhalb von MaaS 3 Konzeption von multimodalen Mobilitätsflatrates und -paketen 3.1 Stakeholder und Ecosysteme 3.1.1 Stakeholder 3.1.2 Ecosysteme 3.2 Kontext und Anforderungen 3.2.1 Technischer Kontext 3.2.2 Regulatorischer und gesetzlicher Kontext 3.2.3 Wirtschaftlicher Kontext 3.3 Produktkonzeption 3.3.1 Allgemeines und Theorie 3.3.2 Produktgestaltung 3.3.3 Produktbündelung 3.3.4 Produktpreisbestimmung und Zahlungsbereitschaft 3.3.5 Produkterweiterung 3.4 Chancen und Risiken 3.5 Business Model Canvas 4 Stand der Umsetzung 4.1 Übersicht Anwendungsbeispiele 4.2 Whim 4.2.1 Geschäftsmodell 4.2.2 Produkt 4.2.3 Erfahrungen und Auswirkungen 4.2.4 Zukunft 4.3 UbiGo 4.3.1 Geschäftsmodell 4.3.2 Produkt 4.3.3 Erfahrungen und Auswirkungen 4.3.4 Zukunft 4.4 swa Mobil-Flat 4.4.1 Geschäftsmodell 4.4.2 Produkt 4.4.3 Erfahrungen und Auswirkungen 4.4.4 Zukunft 4.5 SBB Green Class 4.5.1 Geschäftsmodell 4.5.2 Produkt 4.5.3 Erfahrungen und Auswirkungen 4.5.4 Zukunft 4.6 Zusammenfassung der Praxisbeispiele 5 Weiterentwicklung und Ergänzung um branchennahe Dienstleistungen und Produkte 5.1 Weiterentwicklung 5.1.1 Roaming 5.1.2 Gamification und verhaltensbeeinflussende Maßnahmen 5.1.3 Ticketportfolio 5.1.4 Verhältnis Sharing und Owning 5.2 Ergänzung um branchennahe Dienstleistungen und Produkte 5.2.1 Versorgungs- und Immobilienbranche 5.2.2 Finanz- und Versicherungsbranche 5.2.3 Medienbranche 5.2.4 Lokale Gastronomie und lokaler Einzelhandel 5.2.5 Lieferservices und Logistik 6 Schlussbetrachtung 6.1 Zusammenfassung 6.2 Offene Forschungsfelder 6.3 Schlussfolgerungen und Ausblick Anhang Literaturverzeichni

Thermal shock resistance of ceramic matrix composites

The experimental and analytical investigation of the thermal shock phenomena in ceramic matrix composites is detailed. The composite systems examined were oxide-based, consisting of an aluminosilicate matrix with either polycrystalline aluminosilicate or single crystal alumina fiber reinforcement. The program was divided into three technical tasks; baseline mechanical properties, thermal shock modeling, and thermal shock testing. The analytical investigation focused on the development of simple expressions for transient thermal stresses induced during thermal shock. The effect of various material parameters, including thermal conductivity, elastic modulus, and thermal expansion, were examined analytically for their effect on thermal shock performance. Using a simple maximum stress criteria for each constituent, it was observed that fiber fracture would occur only at the most extreme thermal shock conditions and that matrix fracture, splitting parallel to the reinforcing fiber, was to be expected for most practical cases. Thermal shock resistance for the two material systems was determined experimentally by subjecting plates to sudden changes in temperature on one surface while maintaining the opposite surface at a constant temperature. This temperature change was varied in severity (magnitude) and in number of shocks applied to a given sample. The results showed that for the most severe conditions examined that only surface matrix fracture was present with no observable fiber fracture. The impact of this damage on material performance was limited to the matrix dominated properties only. Specifically, compression strength was observed to decrease by as much as 50 percent from the measured baseline

Affectio societatis

Resumo: O desenvolvimento das sociedades se confunde com a evolução do próprio homem. Embora os romanos tenham nos legado diversas lições que permitem um estudo sistematizado do assunto, não há qualquer dúvida de que as sociedades já eram conhecidas em período ainda mais remoto. Depois de longa e gradual evolução, as sociedades finalmente adotaram, na Idade Média, contornos muito semelhantes àqueles observados nas sociedades atuais. Mas apesar da antiga e abundante discussão, as sociedades continuam ocupando um posto de destaque no debate doutrinário e jurisprudencial, especialmente no tocante às características que diferenciam a sociedade de outras figuras análogas. Uma das mais importantes discussões diz respeito à inclusão da affectio societatis dentre os elementos específicos do contrato de sociedade. Embora pouco se conheça sobre o verdadeiro significado e extensão da expressão latina, a sua aplicação tem sido invocada repetidamente, assumindo diferentes sentidos. Por essas razões, esta dissertação se propõe a analisar as sociedades e, especialmente, a affectio societatis, desde os seus primórdios até o estado atual, com a finalidade de determinar se ela é ou não um elemento específico do moderno contrato de sociedade