bluuebunny/crossref_metadata_2025 huggingface dataset:
Perfil dos Catadores de Materiais Recicláveis nos Lixões de Minas Gerais / Characteristics of the Waste Pickers in Municipal Dumps in the State of Minas Gerais
Authors: Ferreira Frederico Poley Martins , Freitas Danilo Gomes de
Published: July 2015

Neste artigo procurou-se investigar as condições de trabalho e renda dos catadores de materiais recicláveis em lixões a céu aberto no estado de Minas Gerais. Os dados foram obtidos a partir de uma pesquisa tipo “survey”, inclusive numa perspectiva regional, cujos objetivos foram: identificar, dimensionar e caracterizar as principais carências e necessidades desses trabalhadores e de suas famílias. Entre outros aspectos, foram abordados: a Idade, estrutura familiar, renda, condições de trabalho atuais e anteriores ao lixão, formalização e associação. Observou-se que, a maioria dos catadores é do sexo masculino, mas também com importante participação, das mulheres, de jovens e idosos, normalmente, com baixa qualificação e com experiência anterior no mercado formal de trabalho. Como conclusão principal foi enfatizada a importância dos empreendimentos auto gestionários para a melhoria das condições de trabalho, especialmente no atual contexto de mudança da legislação brasileira sobre a disposição final do lixo urbano.Palavras–chave: Catadores, lixo, condições de trabalho, associação.  Abstract In this article was analyzed the labor conditions and income of people who collect recyclable materials in open municipal dumps in the state of Minas Gerais, Brazil. Data were obtained from a survey did with pickers in a regional and municipal perspectives. Individual characteristics like age, family structure, income, workload, work association, previous works and work formalization among others were gotten. The main aim of this research was to obtain data about the needs and problems of these workers and their families. The majority of them are men, with an important share of youths and elderlies, they have low qualifications, and some previous experience in the formal market. As conclusion, the importance of self-managed organizations was emphasized what allow waste pickers improve their income and working conditions, especially in a recent context of change in the Brazil´s waste disposal legislation.Keywords: garbage collectors, recycling, working conditions, Association.
O uso das TICs como ferramenta de ensino-aprendizagem no Ensino Superior / Use of technologies of information and knowledge as teaching-learning tools in higher education
Authors: Lobo Alex Sander Miranda , Maia Luiz Claudio Gomes
Published: July 2015

Este ensaio buscou apresentar algumas formas de utilização das Tecnologias da Informação e Comunicação (TIC) no sistema superior de ensino, como apoio ao ensino-aprendizagem e seus desdobramentos. Foi feita uma revisão literária com intuito de mostrar alguns caminhos e práticas para o ensino-aprendizagem, qual o perfil do novo docente frente a estas novas tecnologias, seu papel na utilização das mesmas e o resultado esperado quando da utilização das mesmas. Algumas ferramentas de TIC, que podem ser utilizadas em pesquisas, exposição de conteúdo e disseminação de conhecimento são apresentadas para este contexto. Como resultados percebemos que a tecnologia é uma auxiliar muito importante no processo de ensino, cabendo às instituições de ensino propor currículos bem elaborados; aos professores serem capacitados e interessados em melhorar constantemente as aulas; os alunos terem interesse e não serem passivos, buscarem constantemente adquirir novos conhecimentos.Palavras-Chave: Tecnologia da Informação e Comunicação (TIC). Ensino-Aprendizagem (EA). Ensino Superior.AbstractThis article aims to present some uses of Information and Communication Technologies (ICT) in teaching superior system to support the teaching - learning and its consequences. A literary review was made with the intention to show some ways and practices for teaching and learning, which the profile of the new teaching front of these new technologies, their role in the use of the same and the expected result when using them. Some ICT tools that can be used in research, content display and dissemination of knowledge are presented in this context. As a result we see that the technology is a very important aid in the teaching process, leaving educational institutions offer well-designed curricula; teachers are qualified and interested in constantly enhance lessons; students have interest and not being passive, seek constantly acquire new knowledge.Keywords: Information and Communication Technology. Teaching and Learning. Higher Education.
O Programa “Minha Casa, Minha Vida” e a provisão de habitação e urbanização em assentamentos precários no Estado do Tocantins, Brasil /The “Minha Casa, Minha Vida” Program and the (...)
Authors: Duarte Samuel Correa , Figueiredo Cesar Alessandro Sagrillo
Published: July 2015

O presente trabalho investiga dados preliminares sobre implementação do Programa "Minhs Casa Minha Vida" no Estado do Tocantins. Foram levantados dados sobre as obras relativas à provisão de moradias e urbanização em assentamentos precários, tanto em execução quanto já concluídas, sua distribuição pelos municípios do Estado e sua relação com o poder público. O objetivo é mapear o perfil e localização das ações do programa em tela com vistas ao atendimento das áreas mais desassistidas de oferta de habitação e infra-estrutura urbana. A análise dos dados obtidos terá como referência a literatura sobre planejamento e avaliação de políticas públicas sem descuidar da história e contexto regional.
Território e territorialismo: a abrangência conceitual e a noção de poder / Territory and territorialism: conceptual scope and the notion of power
Authors: Lobo Carlos , Horta Célio , Garcia Ricardo Alexandrino
Published: July 2015

O presente trabalho procura discutir a produção do território no Brasil, tendo como base o conceito de territorismo. O processo histórico-geográfico de formação da sociedade brasileira foi regido por recorrentes promessas acerca da inserção na modernidade. A noção de desenvolvimento, desdobrada da noção de progresso, foi o combustível social de sustentação desse movimento de inserção das relações capitalistas no Brasil durante o século XX. Assim, a ação prevalecente nos governos, de um modo geral, tem sido a inserção das regiões brasileiras no circuito competitivo capitalista. Contudo, esse processo apresentou diversas distorções, que foram causadoras de movimentos de resistência política em favor da produção de territórios pensados na lógica capitalista-desenvolvimentista. Propõe-se com nesse manuscrito identificar os elementos de um movimento dialético entre a forma de produção territorial baseada nos princípios lógicos do desenvolvimento, alertando para a necessidade de movimentos de contestação dessa racionalidade. Trata-se de um investimento necessário uma vez que a ideário desenvolvimentista tem sido construído, no espaço social brasileiro, sob a influência de suas elites, como uma estratégia de reprodução, que ressalta o discurso em favor da produção de territórios competitivos.Palavras-Chave: Território; Territorialismo; Desenvolvimento.AbstractThis paper discusses the production of territory in Brazil, based on territoriality concept. The historical and geographical process of the Brazilian society formation was governed by recurring promises on the entry in modernity. The notion of development, deployed the notion of progress, was the fuel social support of this insertion movement of relations capitalists in Brazil during the twentieth century. Thus, the prevailing action Governments, in general, has been the insertion of the Brazilian regions in the capitalist competitive circuit. However, this process presented several distortions, which were causing political resistance movements on behalf of the production thought territories in capitalist developmentalist logic. It is proposed with this manuscript identifying the elements of a dialectic movement between the form of territorial production based on logical principles of development, stressing the need for protest movements. This is a necessary investment since developmentalist ideology has been built in the Brazilian social space, under the influence of their elites, as a strategy reproduction, which underscores the speech in favor of the production territoriality competitive.Keywords: Territory; Territory; Development.
Influence of VANET System on Movement of Traffic Flows in Emergency Situations
Authors: Kajackas Algimantas , Žuraulis Vidas , Sokolovskij Edgar
Published: July 2015

The paper presents Vehicular Ad Hoc Network (VANET) system based on an analysis of the movement of a motorcade in an emergency situation. This analysis seeks to answer the question: when and under what conditions Emergency Message (EM) sent by Vehicle-to-Vehicle (V2V) system reaches the final target to help in preventing of serious accidents, such as multi-vehicle collisions. The model of calculation based on the key principles of vehicle braking enables finding the time to possible collision and the residual velocity of the vehicle. In the calculations, the average values of the driver’s reaction time are accepted; in addition, a sent emergency message is considered to be free of interference. Upon choosing different road and driving conditions, it is found what vehicle of the motorcade stops before the possible obstacle on emergency braking. The performance of vehicles with and without VANET system is compared.
Public Transit Service-Opportunities in Commuter-Belt Municipalities – A Systemic Analysis of Two Districts in the Vienna Region
Authors: Brezina Tadej , Schopf Josef Michael , Moncholi y Badillo David
Published: July 2015

Public transport in the transition zone from cities to rural areas is increasingly becoming a focus from the financial and public service provision perspective. The (perceived) supply differences of rural and remote areas are on the agenda of policy discourse. Our survey studies the public transport supply of two districts and their municipalities in the region of Vienna, Austria, by using the parameters of service-opportunities, municipal population, acreage of settlement units and potential demand. Annual service-opportunities is a parameter recorded by the public transport authority of the Vienna region for every single station under its zone of influence. These parameters are analyzed to conclude that service-opportunities pose a viable entity for systematic public transport analysis and differences in supply of these two districts are in contrast to expectations. Finally, we address the need for future development of service-opportunities based analyses.
Pilot Implementation of Public Transport Priority in the City of Zagreb
Authors: Vujić Miroslav , Mandzuka Sadko , Greguric Martin
Published: July 2015

The problem with traffic congestion is particularly expressed in urban areas where possibilities for physical increment of capacity are limited or impossible. Significant in the approach to solving this problem is the usage of Public Transport (PT) and the implementation of various advanced control measures that can improve the quality of overall public transport system. The main objective of this research is to explore the possibilities of implementation of adaptive traffic control on signalized intersections giving priority to public transport vehicles through urban traffic network in the city of Zagreb. The possibilities of implementing public transport priority (PTP) technique in the city of Zagreb are analyzed because of specific traffic situations on defined corridors (location of stops, distance between intersections, etc.). With proper usage of PTP techniques (e.g. adequate detector positions, good estimation of PT vehicle arrival time at intersection) the total tram travel time can be significantly reduced. The Level of Service at intersection may be approximately retained because cross-street traffic demand was not ignored. According to technological level of traffic control system in the city of Zagreb, global implementation of PTP is not possible. So, for each intersection the PTP algorithm was developed separately, but mutual traffic influence of all intersections on the corridor was considered. The cooperative concept application within urban traffic control is considered as well.
Optogenetic feedback control of neural activity
Authors: Newman Jonathan P , Fong Ming-fai , Millard Daniel C , Whitmire Clarissa J , Stanley Garrett B , Potter Steve M
Published: July 2015

Optogenetic techniques enable precise excitation and inhibition of firing in specified neuronal populations and artifact-free recording of firing activity. Several studies have suggested that optical stimulation provides the precision and dynamic range requisite for closed-loop neuronal control, but no approach yet permits feedback control of neuronal firing. Here we present the ‘optoclamp’, a feedback control technology that provides continuous, real-time adjustments of bidirectional optical stimulation in order to lock spiking activity at specified targets over timescales ranging from seconds to days. We demonstrate how this system can be used to decouple neuronal firing levels from ongoing changes in network excitability due to multi-hour periods of glutamatergic or GABAergic neurotransmission blockade in vitro as well as impinging vibrissal sensory drive in vivo. This technology enables continuous, precise optical control of firing in neuronal populations in order to disentangle causally related variables of circuit activation in a physiologically and ethologically relevant manner.
Improved reservoir sizing utilizing observed and reconstructed streamflows within a Bayesian combination framework
Authors: Patskoski Jason , Sankarasubramanian A.
Published: July 2015

Reservoir sizing is a critical task as the storage in a reservoir must be sufficient to supply water during extended droughts. Typically, sequent peak algorithm (SQP) is used with observed streamflow to obtain reservoir storage estimates. To overcome the limited sample length of observed streamflow, synthetic streamflow traces estimated from observed streamflow characteristics are provided with SQP to estimate the distribution of storage. However, the parameters in the stochastic streamflow generation model are derived from the observed record and are still unrepresentative of the long‐term drought records. Paleo‐streamflow time series, usually reconstructed using tree‐ring chronologies, span for a longer period than the observed streamflow and provide additional insight into the preinstrumental drought record. This study investigates the capability of reconstructed streamflow records in reducing the uncertainty in reservoir storage estimation. For this purpose, we propose a Bayesian framework that combines observed and reconstructed streamflow for estimating the parameters of the stochastic streamflow generation model. By utilizing reconstructed streamflow records from two potential stations over the Southeastern U.S., the distribution of storage estimated using the combined streamflows is compared with the distribution of storage estimated using observed streamflow alone based on split‐sample validation. Results show that combining observed and reconstructed streamflow yield stochastic streamflow generation parameters more representative of the longer streamflow record resulting in improved reservoir storage estimates. We also generalize the findings through a synthetic experiment by generating reconstructed streamflow records of different sample length and skill. The analysis shows that uncertainty in storage estimates reduces by incorporating reconstruction records with higher skill and longer sample lengths. Potential applications of the proposed methodology are also discussed.
Morphodynamic response of a variable‐width channel to changes in sediment supply
Authors: Nelson Peter A. , Brew Andrew K. , Morgan Jacob A.
Published: July 2015

River channels commonly exhibit downstream variations in channel width, which can lead to the development of alternating shallow and deep areas known as riffle‐pool sequences. The response of these channels to variations in sediment supply remains largely unexplored. Here we investigate the morphodynamic response of a variable‐width channel to changes in sediment supply through laboratory experiments conducted in a straight flume in which we imposed sinusoidal variations in width. We first developed equilibrium conditions under a constant sediment supply and then eliminated the sediment feed to create a degraded, armored bed. This sediment‐starved bed was subjected to two types of sediment supply increases: a return to the initial constant supply, and the introduction of a well‐sorted sediment pulse (analogous to gravel augmentation). Riffles and pools formed in wide and narrow areas, respectively, and the location of and relief between riffles and pools remained the same throughout all experimental runs, regardless of the sediment supply. The primary channel response to changes in supply was adjustment of the overall slope. The sediment pulse evolved primarily through dispersion rather than translation, which contrasts with prior gravel augmentation experiments conducted in constant‐width channels and suggests that width variation and resulting riffle‐pool topography enhances pulse dispersion. Our results indicate that width variation is a primary control on the location and relief of riffles and pools in straight channels, and sediment supply changes are unlikely to affect riffle‐pool morphology when bank geometry is fixed and water discharge is steady.
Synthetic Crystals of Silver with Carbon: 3D Epitaxy of Carbon Nanostructures in the Silver Lattice
Authors: Salamanca‐Riba Lourdes G. , Isaacs Romaine A. , LeMieux Melburne C. , Wan Jiayu , Gaskell Karen , Jiang Yeping , Wuttig Manfred , Mansour Azzam N. , Rashkeev Sergey N. , Kuklja Maija M. , Zavalij Peter Y. , Santiago Jaime R. , Hu Liangbing
Published: July 2015

Only minimum amounts of carbon can be incorporated into silver, gold, and copper in a thermodynamically stable form. Here, the structure of stable silver carbon alloys is described, which are produced by thermoelectrically charging molten silver with carbon ions. Transmission electron microscopy and Raman scattering are combined to establish that large amount of carbon is accommodated in the form of epitaxial graphene‐like sheets. The carbon bonds covalently to the silver matrix as predicted from density functional theory (DFT) calculations with bond energies in the range 1.1–2.2 eV per atom or vacancy. Graphitic‐like sheets embedded in the crystal lattice of silver form 3D epitaxial structures with the host metal with a strain of ≈13% compared to equilibrium graphene. The carbon nanostructures persist upon remelting and resolidification. A DFT‐based analysis of the phonon density of states confirms the presence of intense vibration modes related to the AgC bonds observed in the Raman spectra of the alloy. The solid silver–high carbon alloy, termed “Ag‐covetic,” displays room temperature electrical conductivity of 5.62 × 107S m−1even for carbon concentrations of up to ≈6 wt% (36 at%). This process of incorporation of carbon presents a new paradigm for electrocharging assisted bulk processing.
Engineering the Magnetic Dipolar Interactions in 3D Binary Supracrystals Via Mesoscale Alloying
Authors: Yang Zhijie , Wei Jingjing , Bonville Pierre , Pileni Marie‐Paule
Published: July 2015

Inspired by metallic alloys in atomic solids, two distinct metallic nanoparticles are used, considered as “artificial metal atoms,” to engineer ordered binary nanoparticle alloys at the mesoscale, called binary supracrystals. Here, ferromagnetic 7.2 nm Co nanoparticles are used as large “A” site particles, while either ferromagnetic 4.6 nm Co or nonmagnetic 4.0 nm Ag nanoparticles are used as small “B” site particles to fabricate long‐range ordered binary supracrystals with a stoichiometry of AB2 and AB13. The interparticle distances between 7.2 nm Co nanoparticles within the Co/Ag binary supracrystals can be tuned by a control of crystal structure from AB2 (CoAg2) to AB13 (CoAg13). A decrease of magnetic coupling between Co nanoparticles is observed as the Co–Co interparticle distance increases. Furthermore, by alloying 7.2 and 4.6 nm Co nanoparticles to form AB2 (CoCo2) binary supracrystals, a collective magnetic behavior of these two particle types, due to the dipolar interaction, is evidenced by observing a single peak in the zero‐field‐cooled magnetization curve. Compared with the CoAg2 binary supracrystals, a spin orientation effect in sublattice that reduces the dipolar interactions in the supracrystals is uncovered in CoCo2 binary supracrystals.
Dye Encapsulated Metal‐Organic Framework for Warm‐White LED with High Color‐Rendering Index
Authors: Cui Yuanjing , Song Tao , Yu Jiancan , Yang Yu , Wang Zhiyu , Qian Guodong
Published: July 2015

A strategy by encapsulating organic dyes into the pores of a luminescent metal‐organic framework (MOF) is developed to achieve white‐light‐emitting phosphor. Both the red‐light emitting dye 4‐(p‐dimethylaminostyryl)‐1‐methylpyridinium (DSM) and the green‐light emitting dye acriflavine (AF) are encapsulated into a blue‐emitting anionic MOF ZJU‐28 through an ion‐exchange process to yield the MOF⊃dye composite ZJU‐28⊃DSM/AF. The emission color of the obtained composite can be easily modulated by simply adjusting the amount and component of dyes. With careful adjustment of the relative concentration of the dyes DSM and AF, the resulting ZJU‐28⊃DSM/AF (0.02 wt% DSM, 0.06 wt% AF) exhibits a broadband white emission with ideal CIE coordinates of (0.34, 0.32), high color‐rendering index value of 91, and moderate correlated color temperature value of 5327 K. Such a strategy can be easily expanded to other luminescent MOFs and dyes, thus opening a new perspective for the development of white light emitting materials.
Refinement of the postnatal growth restriction locus of chromosome 5q12‐13 deletion syndrome
Authors: Holder J. Lloyd , Cheung Sau‐Wai
Published: July 2015

Individuals with deletions of chromosome 5q12‐13 have rarely been reported and have a range of phenotypes including postnatal growth restriction, intellectual disability, hyperactivity, and ocular abnormalities. Most individuals reported have large deletions or complex rearrangements which have made identifying genes responsible for these phenotypes challenging. Here we report an individual with a chromosome 5q12‐13 deletion with intellectual disability, hyperactivity and restricted linear growth. Based on the location of our patient's deletion in relation to the previously reported deletions, we have narrowed the locus for postnatal growth restriction to less than 1 megabase. Further refinement of this locus with reports of additional individuals with deletions of this region will allow for better understanding of the gene(s) responsible for this phenotype. © 2015 Wiley Periodicals, Inc.
Registry analysis supports different mechanisms for gastroschisis and omphalocele within shared developmental fields
Authors: Benjamin Bonna , Wilson Golder N.
Published: July 2015

Nine thousand two hundred eighty abnormalities associated with 2,943 abdominal wall defects (AWD) encoded from 1999 to 2008 by the Texas Birth Defects Registry (TBDR) were classified and analyzed for mechanism, beginning with 1,831 gastroschisis cases, 774 (41%) with 2,368 associated anomalies (AA) and 814 of omphalocele, 727 (89%) with 4,092 AA. Typical AA profiles for Trisomy 18 (23% of omphalocele cases) and Beckwith–Wiedemann syndrome (15%) validated registry AA descriptors, chromosome disorders surprisingly accounting for 24% of known conditions with gastroschisis followed by expected amniotic band (ADAM) complex (23%) and amyoplasia/arthrogryposis (16%). Separation of known diagnoses, fetal‐stillbirth cases, and transitional or secondary AA left 330 cases of gastroschisis with 594 AA (452 major, 142 minor) and 295 cases of omphalocele with 956 AA (683 major, 273 minor). Anomalies suggestive of vascular origin (intestinal atresias, amyoplasia, bands) were more frequent with gastroschisis and those of defective lateral folding (exstrophies, limb‐body wall defects) with omphalocele. Most AA favoring omphalocele had parallel frequencies with gastroschisis, whether by system/region—for example, cardiac AA (10% of cases), contractures (4.7%), limb (3.7%), CNS (3.2%) for gastroschisis versus cardiac (35%), contractures (14%), digestive‐excretory‐trunk‐axial (all ∼11%), CNS (9.9%) for omphalocele—or for particular minor/major AA—for example, micrognathia (0.72% versus 3.3%), spina bifida (0.59% versus 3.9%), anal atresia (0.73% versus 6.4%), two‐vessel cord (0.22% versus 5.6%). Similar frequencies of many AA reflective of early patterning support common AWD origin within early developmental fields and reinforce the use of large birth defect numbers from suitably qualified registries to define anomaly mechanism as well as prevalence. © 2015 Wiley Periodicals, Inc.
Health utility outcomes in patients undergoing medical management for chronic rhinosinusitis: a prospective multiinstitutional study
Authors: Luk Lauren J. , Steele Toby O. , Mace Jess C. , Soler Zachary M. , Rudmik Luke , Smith Timothy L.
Published: July 2015

Background

A health utility value represents an individual's preference for living in a specific health state and is used in cost‐utility analyses. This study investigates the impact of continuing medical therapy on health utility outcomes in patients with chronic rhinosinusitis (CRS).

Methods

The Medical Outcomes Study Short Form‐6D (SF‐6D) questionnaire was administered to patients prospectively enrolled in a longitudinal study examining treatment outcomes for CRS. Patients were prescribed robust, initial medical therapy and then elected to continue with medical therapy (n = 40) or undergo endoscopic sinus surgery (ESS), followed by medical therapy (n = 152). Patients observed through treatment crossover to ESS were also evaluated (n = 20). Health utility values (SF‐6D) were generated at baseline, 6‐months, and 12‐months follow‐up for both cohorts and evaluated using repeated measures analysis of variance (ANOVA).

Results

Treatment crossover patients were found to have a significantly higher prevalence of previous sinus surgery compared to medical management (χ2 = 6.91; p = 0.009) and surgical intervention (χ2 = 8.11; p = 0.004) subgroups. Mean baseline utility value for the medical therapy cohort was significantly better compared to the ESS cohort (mean ± standard deviation; 0.76 ± 0.12 vs 0.70 ± 0.15; p = 0.023). Significant improvement in health utility was reported in the ESS cohort (F(2) = 37.69; p < 0.001), whereas values remained stable, without significant improvement, in both the medical therapy cohort (F(2) = 0.03; p = 0.967) and treatment crossover cohort (F(2) = 2.36; p = 0.115).

Conclusion

Patients electing continued medical management report better baseline health utility compared to patients electing ESS. Patients electing ESS show significant improvement in health utility, whereas those electing continued medical management demonstrate stable health utility over 12 months.
Kovalente Proteinmarkierung durch enzymatische Phosphocholinierung
Authors: Heller Katharina , Ochtrop Philipp , Albers Michael F. , Zauner Florian B. , Itzen Aymelt , Hedberg Christian
Published: July 2015

Wir präsentieren eine neue Methode zur Proteinmarkierung, die auf der kovalenten enzymatischen Phosphocholinierung einer spezifischen Octapeptidsequenz intakter Proteine beruht. Das Enzym AnkX aus Legionellen wurde etabliert, um funktionalisierte Phosphocholingruppen aus synthetischen CDP‐Cholin‐Derivaten auf N‐ und C‐Termini, sowie interne Schleifenregionen zu übertragen. Zudem kann die kovalente Modifikation durch das Legionellen‐Enzym Lem3 hydrolytisch entfernt werden. Lediglich eine 8 Aminosäuren kurze Peptidsequenz und eine kleine Verbindungsgruppe (PEG‐Phosphocholin) sind für die effiziente Proteinmarkierung erforderlich.
1,4‐Diketones from Cross‐Conjugated Dienones: Potassium Permanganate‐Interrupted Nazarov Reaction
Authors: Kwon Yonghoon , Schatz Devon J. , West Frederick G.
Published: July 2015

A domino potassium permanganate‐interrupted Nazarov reaction to yield syn‐2,3‐disubstituted 1,4‐diketones via a decarbonylative cleavage of the Nazarov oxyallyl intermediate, believed to be without precedent, is presented. This process allows syn substituents to be established stereospecifically on the 2‐carbon bridge connecting the ketone carbonyl carbons, and the formation of one carbon–carbon and two carbon–oxygen bonds. Two carbon–carbon bonds are cleaved in this process.
Plasticized poly(vinyl chloride) composites: Influence of different nanofillers as antimigration agents
Authors: Gholami Abed , Hajian Morteza , Rafiemanzelat Fatemeh , Zanjanijam Ali Reza
Published: July 2015

In this study, plasticized poly(vinyl chloride) (PVC) composites with different nanofillers, including single‐walled carbon nanotubes (SWCNTs), organoclay, TiO2, and ZnO nanoparticles, were prepared, and their effects on plasticizer migration were investigated. Scanning electron micrographs revealed the dispersion quality of the nanofillers in the polymer matrix. It had a significant influence on the performance of the nanofillers in the process of plasticizer migration. Migration and exudation tests showed that the nanofillers could efficiently hinder plasticizer migration. On the basis of these results, we concluded that carbon nanotubes were the best antimigration agent in the plasticized system. This was ascribed to the high aspect ratio of the SWCNTs and the good interactions between them and the plasticizer. Also, TiO2 nanoparticles showed a better performance compared to the ZnO nanoparticles. This was due to the more homogeneous dispersion of the TiO2 in the polymer matrix and the higher surface area of the particles. The differential scanning calorimetry thermograms were in good agreement with the migration tests. The lowest change in the glass‐transition temperature was observed for the composite filled with SWCNTs. This indicated that a lower amount of the plasticizer migrated from PVC. The thermogravimetric analysis curves showed that the incorporation of the nanofillers improved the thermal stability of the PVC. The results could be useful for determining the efficiency of plasticized PVC in applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42559.
Production of sulfonated polyetheretherketone/polypropylene fibers for photoactive textiles
Authors: Mylläri Ville , Fatarella Enrico , Ruzzante Marco , Pogni Rebecca , Baratto Maria Camilla , Skrifvars Mikael , Syrjälä Seppo , Järvelä Pentti
Published: July 2015

New photocatalytic fibers made of sulfonated polyetheretherketone (SPEEK)/polypropylene (PP) are melt compounded and melt spun, first on laboratory scale and then on a semi‐industrial scale. Fiber spinnability is optimized and the fibers are characterized using mechanical testing, electron paramagnetic resonance (EPR) spectroscopy, and scanning electron microscopy (SEM). According to the results, the fiber spinnability remains at a good level up to 10 wt % SPEEK concentration. Optimal processing temperature is 200°C due to the thermal degradation at higher temperatures. EPR measurements show good and long‐lasting photoactivity after the initial irradiation but also decay in the radical intensity during several irradiation cycles. Mechanical tenacity of the SPEEK/PP 5:95 fiber is approximately 20% lower than for otherwise similar PP fiber. The fiber is a potential alternative to compete against TiO2‐based products but more research needs to be done to verify the real‐life performance. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2015,132, 42595.
A high temperature polymer of phthalonitrile‐substituted phosphazene with low melting point and good thermal stability
Authors: Zhao Fenghua , Liu Ruojin , Yu Xiaoyan , Naito Kimiyoshi , Qu Xiongwei , Zhang Qingxin
Published: July 2015

A phthalonitrile‐substituted phosphonitrilic monomer has been synthesized from phosphonitrilic chloride trimer and then polymerized with addition of 4‐(hydroxylphenoxy)phthalonitrile (HPPN). The chemical structures of the phosphonitrilic monomer and polymer were characterized by Fourier Transform Infrared spectroscopy (FT‐IR) and proton Nuclear Magnetic Resonance spectroscopy (1H NMR). Curing behaviors and thermal stabilities of the polymer were investigated through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Analysis showed that the monomer has large processing temperature window and good thermal stability. Apparent activation energy, initial curing temperature (Ti), curing temperature (Tp), and termination curing temperature (Tf) of the phosphonitrilic polymer were explored. Dynamic mechanical analysis (DMA), glass transition temperature (Tg) were studied, and limiting oxygen index (LOI) were estimated from the van Krevelen equation, which indicates the polymer process high modulus and good flame retardance. Micro‐scale combustion calorimetry (MCC) was also used for evaluating the flammability of the polymers. Postcuring effects were explored, showing excellent thermal and mechanical properties with postcuring. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42606.
Investigation on morphology and properties of melt compounded polyoxymethylene/carbon nanotube composites
Authors: Lin Leyu , Schlarb Alois K.
Published: July 2015

Polyoxymethylene nanocomposites containing different contents of carbon nanotubes were produced by a two‐step melt compounding process using a twin‐screw extruder. The dispersion quality, thermal and mechanical properties, and the creep as well as the tribological behaviors of the nanocomposites were investigated. Morphological investigations show that the masterbatch dilution process significantly improves the dispersion quality of carbon nanotubes within polyoxymethylene matrix, and as a consequence, enhanced mechanical properties and creep resistance are gained. Furthermore, to predict the long‐term property based on the short‐term experimental data, the time–temperature superposition principle and Findley model were used. Master curves with extended time scale are constructed using time–temperature superposition principle to horizontally shift the short‐term experimental data. The simulated results confirm the reinforced creep resistance by incorporation of the carbon nanotubes into the polymer matrix even at extended long time scale. By contrast, the tribological performance of polyoxymethylene was remarkably impaired after adding carbon nanotubes. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42639.
Current integration of dissection in medical education in Australia and New Zealand: Challenges and successes
Authors: Bouwer Hope Ellen , Valter Krisztina , Webb Alexandra Louise
Published: July 2015

The reduced use of dissection associated with the introduction of integrated systems problem‐based learning curricula, graduate‐entry programs and medical school expansion is a frequent topic of discussion and debate in modern medical training. The purpose of this study was to investigate the impact of these changes to the medical education landscape, by looking at the current utilization and integration of dissection in medical schools, in Australia and New Zealand. A survey and an invitation to participate in an interview were distributed to all Australian Medical Council‐accredited medical schools. Sixteen schools (76%) responded to the survey and five interviews (24%) were conducted. Dissection was a component of the medical program in 12 of the 16 schools surveyed. The opportunity for medical students to dissect human cadavers was found to be related to whether the medical school was established pre‐ or post‐2000 (P = 0.003) but was not significantly associated to undergraduate‐ or graduate‐entry (P = 0.64), program length (P = 0.59) or the number of commencing students (P = 0.07). The methods used for the delivery and integration of dissection varied between schools. Despite substantial changes to the delivery of anatomy in Australian and New Zealand medical schools, a variety of approaches have been adopted to ensure dissection remains an integral component of medical student education. Based on our findings, a number of recommendations were formulated to encourage the integration of dissection, regardless of the didactics of the program, to enhance the anatomical knowledge of students. Anat Sci Educ 9: 161–170. © 2015 American Association of Anatomists.
A methodology for integrated critical spare parts and insurance management
Authors: Martínez Alejandro , Pascual R. , Maturana Sergio
Published: July 2015

Critical spare‐parts stock optimization has become a relevant topic for academy and industry. In most articles, the problem has been stated as a trade‐off between economic risks of shortages and financial costs. Risk optimization in this context has been mainly studied from a logistics point of view. The most common decision variables have been stock levels, stock location, and reorder points. In this context, buying insurance to cover shortage cost can be a complementary (or exclusive) measure for risk mitigation. Insurance optimization traditionally has been studied from a microeconomic and financial perspective. The main decision variable has been the indemnity function, and occasionally, the insurance premium. Its use in the context of physical asset management has not been observed to the best of our knowledge. This creates an opportunity to link inventory optimization techniques with insurance optimization for shortage losses. In this work, we present a novel approach to jointly manage the shortage risk of a critical non‐repairable component in a unique critical system. We develop an original model to integrate critical spare‐parts stock optimization with insurance optimization techniques. The result is a decision model to select the optimal stock and insurance policy that maximizes the decision maker's expected utility. This allows for a business‐centered integrated perspective in critical parts decisions. We present a case study representative of the mining industry, illustrating the complementary nature of selecting optimal stock levels and contracting an optimal insurance. Our results show that contracting an insurance can lead to policies preferred by a risk‐averse decision maker. The case study shows that this may even occur lowering stock levels and increasing profits. Copyright © 2015 John Wiley & Sons, Ltd.
Untersuchungsstrategie zur Bewertung der Langzeitstabilität von Dehnungsmessstreifen
Authors: Herrmann Ralf , Stockmann Martin , Marx Steffen
Published: July 2015

Im Bauwerksmonitoring werden neben Temperaturen und Verschiebungen meist Dehnungen gemessen. Dies dient u. a. dazu, den Ausnutzungsgrad und die Betriebsfestigkeit zu beurteilen. Ein sehr gebräuchliches Verfahren zur Bestimmung von Dehnungen an und in Bauteilen ist die Messung mit Dehnungsmessstreifen (DMS). Für die Beurteilung der Langzeitstabilität von Dehnungsmessstreifen wird im Folgenden eine Klimaprüfung vorgestellt, die eine beschleunigte Beanspruchungseinwirkung durch Temperatur‐ und Feuchteschwankungen simuliert. Dieser sich wiederholende Zyklus besteht aus vier Phasen, die insgesamt 240 h umfassen und dabei unterschiedliche Kombinationen von Temperatur und Luftfeuchtigkeit bis hin zu Frost‐Tau‐Wechseln beinhalten. Anhand von Ergebnissen aus durchgeführten Langzeituntersuchungen über einen Zeitraum von 85 d werden Kenngrößen zur Charakterisierung der Langzeitstabilität von Dehnungsmessstreifen abgeleitet. Die Messergebnisse zeigen Unterschiede in der Nullpunktdrift zwischen den einzelnen Typen von Dehnungsmessstreifen und welche Bedeutung der Auswahl und dem Schutz von Dehnungsmessstreifen beigemessen werden muss.

Test strategy for evaluation of strain gauge long term stability

In the field of structural health monitoring the measuring of strain is prevalent beside temperature and displacement. The strain is used to determine the utilization rate and to estimate the fatigue strength of a structure. A very common measurement method for strains at and in components is the usage of strain gauges. Further, a climate cycle for analysis of long term stability of strain gauges is introduced, that simulates an accelerated temperature and humidity stress. This cycle consists of four phases, which lasts 240 h and covers different combinations of temperature and humidity conditions up to freezing and thawing. The results of a 85 d lasting long term test are presented and used to describe characteristic values for long term stability of strain gauges. The measurement results show significant differences for the strain gauge types in the zero point drift and underline the role of correct choice and protection to achieve reliable strain measurements.
Die Autobahn‐Talbrücke bei Rüdersdorf
Authors: Braun Michael
Published: July 2015

Im Sommer 1937 ist am Berliner Autobahn‐Ring die sogenannte Osttangente in den Betrieb gegangen. Damit wurde auch eine der später bekanntesten Brücken im gesamten deutschen Autobahnnetz erstmals befahren. Verstörend muss noch heute wirken, dass diese Brücke bis zu ihrer nahezu kompletten Erneuerung im kollektiven Gedächtnis leider sehr viel weniger wegen ihrer ausgezeichneten ästhetischen Wirkung, denn wegen der einstmals an ihr aufgetretenen Schäden hinterlegt ist. Konsequenterweise sind neben einem enormen Konvolut zu den Schäden kaum neutrale Veröffentlichungen zu der Brücke zu finden [1, 2].

The highway bridge near Rüdersdorf

In the summer of 1937 the eastern part of the Berlin highway circle was opened to traffic. Thus one of the later on best known bridges was put into use. It seems to be a little bit confusing, that a majority won't remember the bridge because of its size, but rather of its disruption. Consequentially you can find very few neutral papers about this structure.
Verlängerung und Grundinstandsetzung der Nordkammer Schleuse Kersdorf
Authors: Thumernicht Sven , Lindlar Hans‐Gerd , Jacob Karsten
Published: July 2015

Mit dem Ziel, die wichtigen Industrie‐ und Gewerbestandorte entlang der Spree‐Oder‐Wasserstraße (SOW) weiter nachhaltig an das transeuropäische Binnenwasserstraßennetz anzubinden, führt der Bund seit dem Jahr 2005 Grundinstandsetzungen für die Schleusen am Oder‐Spree‐Kanal aus. Diese beinhalten unter anderem eine Erhöhung der nutzbaren Kammerlänge jeweils von 57 m auf 115 m. Die über 100 Jahre alte Nordkammer der Schleuse Kersdorf wurde grundhaft instand gesetzt und in Spundwandbauweise verlängert. Die vorhandene Kammerbreite von 9,80 m ist im verlängerten Kammerteil beibehalten worden. Mit dem vorliegenden Bericht soll ein Einblick in die Planung, Prüfung und Realisierung des Vorhabens gegeben werden. In diesem Zusammenhang wird auf Besonderheiten eingegangen, die einerseits hohe Anforderungen an Bauherr und Ausführende stellen, andererseits aber typisch für Maßnahmen zur Erhaltung der Infrastruktur im Bestand sind. Im Auftrag des Wasserstraßen‐Neubauamtes Berlin wurde das Bauvorhaben 2013 fertiggestellt und erforderte Investitionskosten von ca. 14 Mio. €.

Elongation and restoration of the Nordkammer Schleuse Kersdorf

Since 2005 the federal government is realising reinstatement work on the locks of the Oder‐Spree‐Channel to provide a sustainable connection for the most important industrial and commercial locations along the Spree‐Oder‐Waterway (SOW) to the trans‐european inland waterway. Part of this project is an increase of the usable chamber length each from 57 m up to 115 m. The more than 100 years old “Nordkammer Schleuse Kersdorf” (northern part of the lock in Kersdorf) has been reconstructed and elongated with a sheet piling construction. In this process the goal to keep the existing width of the chamber at 9.8 m throughout the new length of the construction was achieved. The given report should provide insights of the planning, testing and realisation of the construction project. Hence, special features will be outlined which challenge the building‐owner as well as the contractor, by being typical for actions in the preservation of infrastructure in existing constructions. This project was completed in 2013 and required overall costs in the amount of approximately 14 million euros. Principal was the Wasserstraßen‐Neubauamt Berlin.
Brücken aus der Sicht des Wasserbauers
Authors: Pohl Reinhard
Published: July 2015

Bei Hochwasserereignissen konnte verschiedentlich festgestellt werden, dass Brücken über Wasserläufen den Abfluss behindern und Überschwemmungen angrenzender Gebiete fördern oder verursachen. Im vorliegenden Beitrag werden wichtige Grundsätze der konstruktiven Ausbildung von Brücken aus wasserbaulicher Sicht dargestellt, die notwendig sind, um gebrauchstaugliche und dauerhafte Bauwerke zu errichten.

Bridges from the viewpoint of a hydraulic engineer

During river floods it has often been observed that bridges could obstruct the flow of the water and enhance or cause inundations of the adjacent areas. In this paper some significant principles of the constructional design of bridges are discussed from a hydraulic engineer's viewpoint to ensure the erection of useable and durable structures.
Erweitertes Modell zur Berechnung der Rissbreite
Authors: Empelmann Martin , Krakowski Waldemar
Published: July 2015

Die Beschränkung der auftretenden Rissbreiten ist bei Stahlbetonbauteilen eine maßgebliche Bemessungsaufgabe zur Sicherstellung der Gebrauchstauglichkeit und Dauerhaftigkeit. Im vorliegenden Beitrag wird ein neues, praxisgerechtes Modell zur Berechnung der charakteristischen Rissbreite vorgestellt, welches auf allgemeingültigen mechanischen Ableitungen aufbaut und den charakteristischen Rissabstand sowie die zugehörigen charakteristischen Dehnungen über eine konsistente, verbundorientierte Methodik bestimmt. Die Bestimmungsgleichungen wurden in einer umfangreichen Parameterstudie ermittelt, sodass das neue Berechnungsmodell den Ansatz des EC2/NA [2] bzw. der DIN 1045‐1 [10] im Hinblick auf verbundspezifische und rissmechanische Zusammenhänge verbessert und den Anwendungsbereich in der praktischen Anwendung erweitert.

Extended model to calculate the crack width

The calculation of the crack widths is a main task within the design of reinforced concrete structures in order to secure the serviceability and the durability. In the following a new, practical model for the calculation of the characteristic crack width is presented, which is based on general mechanical relationships and determines the characteristic crack spacing and the associated characteristic strains with a consistent, bond‐oriented methodology. The calculation formulas were determined in an extensive parameter study so that the new calculation model improves the approach of the EC2/NA [2] or DIN 1045‐1 [10] in terms of bond specifics and crack mechanics and extends the application range in the practical use.