bluuebunny/crossref_metadata_2025 huggingface dataset:
New Solution of a Spherically Symmetric Static Problem of General Relativity
Authors: Vasiliev Valery
Published: August 2017

The paper is concerned with the spherically symmetric static problem of the General Relativity Theory. The classical solution of this problem found in 1916 by K. Schwarzschild for a particular metric form results in singular space metric coefficient and provides the basis of the objects referred to as Black Holes. A more general metric form applied in the paper allows us to obtain the solution which is not singular. The critical radius of the fluid sphere, following from this solution does not coincide with the traditional gravitational radius. For the spheres with radii that are less than the critical value, the solution of GRT problem does not exist.
Who is Who? Identifying the Different Sub-groups of Secondary Stakeholders within a Community: A Case Study of the Niger Delta Region of Nigeria Communities
Authors: Osobajo Oluyomi A. , Moore David
Published: August 2017

The Nigerian oil and gas industry (NOGI) has over time been dominated by the Nigerian government and oil producing companies (OPCs). The influences of the community stakeholder on OPCs in the last three decades have been expressed in diverse ways by different community sub-groups through their concerns and interests, some of which have severely impacted on the NOGI. Community within this context is categorised as a primary stakeholder, while the sub-groups are secondary stakeholders that emerge from within the community. Hence, the success of the NOGI largely depends on the Nigerian government and the oil producing companies, and other players such as Non-Governmental Organisations recognising the community as a key player and having appropriate knowledge of the different sub-groups of secondary stakeholders within the community in order to understand their intentions, behaviour, interests, influences and interrelations. Such knowledge is relevant to the NOGI’s formulation of future oil and gas strategy.This study commences with an overview of the primary stakeholders (i.e. the Nigerian government, OPC and the community), their respective activities, participation and the link between these stakeholders with a specific focus on the NOGI context. Subsequently, various sub-groups of secondary stakeholders within the community and their respective interest(s) are identified in detail.
Applying Kolmogorov-Zurbenko Adaptive R-Software
Authors: G Zurbenko Igor , Sun Mingzeng
Published: August 2017

The Kolmogorov-Zurbenko Adaptive, kza package provides algorithms to deal with abrupt changes or breaks in the presence of heavy background noise. In a practical way, one-dimensional and high-dimensional simulated samples are generated to demonstrate signal recoveries and their accuracy evaluation by mean of squared error, mean difference and specificity index. Simulation investigation showed that smoothing window size need consider whenever applying kza package, and that kza could tolerate background noise about 10-folds heavier in higher-dimensional data compared to 1-dimensional data.
An Analysis of the Composition, Health Benefits, and Future Market Potential of the Jerusalem Artichoke in Canada
Authors: Munim Adil , Rod Michel , Tavakoli Hamed , Hosseinian Farah
Published: August 2017

This article presents an overview of the Jerusalem artichoke and its potential uses in consumer food products. Jerusalem artichoke, native to North America, is characterized by its sunflower-like appearance and carbohydrate-rich tubers. For centuries, Jerusalem artichoke tubers were a food source for Aboriginal Canadians and early European settlers. Today, Jerusalem artichoke is used to obtain inulin for addition into food products. Inulin is a polysaccharide that provides several health benefits when consumed. Due to its unique structure of fructose and glucose molecules, inulin is indigestible by the human digestive system. Its benefits are realized when it enters the large intestine and is fermented by microorganisms. This process stimulates prebiotic and dietary fibre effects that improve the growth of beneficial bacteria and promote greater digestive health. Additionally, inulin can act as a sugar or fat substitute in foods, and even facilitates the absorption of minerals in the large intestine. Currently, the use of Jerusalem artichoke inulin in commercial food products is limited. However, trends focusing on healthy living and supporting local industry indicate that Canadian consumers will positively view products made with Canadian-grown Jerusalem artichoke. The advantage that Jerusalem artichoke has over other inulin-rich products is that it can grow on poor land and is also more resistant to extreme weather conditions relative to corn and/or sugar beet; this is significant in the Canadian context. Given these trends and supplementary market data, the potential market size for Jerusalem artichoke-enriched products has been determined. Additionally, prices of currently available inulin-enriched products have been used as guidelines to determine total market potential. Market potential for baked goods, particularly muffins, was found to be $CAD 8,721,788 while market potential for beverages, namely soda, was found to be $CAD 11,707,098. These numbers, though imperfect, indicate that there is strong potential for Jerusalem artichoke-enriched products to be marketed to Canadian consumers.
Psychometric properties from a Spanish validation of Depressive Experiences Questionnaire (DEQ)
Authors: Linares Leticia , Herrero-Fernández David , Iriarte Leire , Estévez Ana
Published: August 2017

Introduction: This study assessed the psychometric prop­erties of the Spanish translation of the Depressive Expe­riences Questionnaire (DEQ). This questionnaire measures two different personality dimensions vulnera­ble to two different subtypes of depression, anaclitic de­pression and introjective depression, respectively. Ob­jectives: The aims of this study are to assess the psy­chometric properties of Spanish translation of Depres­sive Experiences Questionnaire and its relationship with at­tachment styles. Method: The sample (N = 416) con­sisted of undergraduate students with a mean of 27.63 (ST = 10.98) years old. The administration was collec­tive and taken under the supervision of the researcher. Results: The results showed good internal consistency, similar to that of other studies. The findings showed sig­nificant re­lationships with other instruments measuring depressive symptomatology and confirmed the hypothe­sis of a rela­tionship between the DEQ and attachment style. Conclu­sion: The Spanish version of the DEQ could be an in­strument for distinguishing the types of personality vul­nerability to different expressions of de­pression in the Spanish population.
Percepción de los deportistas sobre el estilo de liderazgo de los entrenadores y la tendencia a cooperar en equipos competitivos
Authors: Lameiras João , Martins Bruno , Lopes-De-Almeida Pedro , García-Mas Alexandre
Published: August 2017

ResumenEl propósito del presente estudio fue descubrir las rela­ciones entre los comportamientos del entrenador percibi­dos por los deportistas durante el entrenamiento y la competición y la cooperación a través de la red baye­siana. Los deportistas masculinos profesionales de varios deportes de equipo (N = 158) completaron la versión portuguesa de la Escala de Liderazgo para el Deporte y el Cuestionario de Cooperación Deportiva para evaluar la cooperación. Se identificaron relaciones entre los comportamientos percibidos del entrenador en entornos de entrenamiento y competición y la tendencia de los atletas a cooperar. En general, los hallazgos apoyan que, en el deporte, los comportamientos del entrenador con­gruentes con las necesidades individuales de los atletas y adaptados a las demandas situacionales pueden promo­ver el comportamiento prosocial. AbstractThe purpose of the present study was to discover the relationships between athletes’ perceived coach behaviors during training and competition, and cooperation via Bayesian network (BN). Professional male atheletes from several team sports (N = 158) completed the Portuguese version of the Leadership Scale for Sport and the Questionário de Cooperação Desportiva to assess cooperation. Relationships were identified between perceived coach behaviors in training and competition environments and with athletes tendency to cooperate. Overall, the findings support that in sports, coaching behaviours congruent with the athletes’ individual needs and adapted to the situational demands may promote prosocial behaviour.
Valoración de la percepción subjetiva de la fatiga en motoristas de competición Rally-Raid Dakar
Authors: Gil-Moreno-De-Mora Gonzalo , Palmi Guerrero Joan , Prat-Subirana Joan Antoni
Published: August 2017

ResumenLos deportistas que participan en el Rally-raid Dakar deben mostrar su competencia para dar respuesta a un esfuerzo de larga duración en el que intervienen factores limitantes de carácter psicológico y fisiológico por la fatiga acumulada durante el esfuerzo. El objetivo de esta investigación fue analizar la idoneidad de diferentes instrumentos de evaluación de la percepción de fatiga de motoristas en competición. El diseño de investigación es de caso único, con un participante (motorista). El estudio consistió en la realización de dos sesiones de entrenamiento que se desarrollaron en un circuito simulando las condiciones de distancia y dificultad propias de una etapa. Los instrumentos de registro fueron el cuestionario POMS (McNair, Lorr y Droppleman, 1971), la escala RPE-Borg (Borg, 1982), para el registro de la percepción del esfuerzo realizado y las escalas EVA-fatiga (Lee, Hicks y Nino, 1991) y SEES (McAuley y Courneya, 1994) para valorar la percepción de fatiga. En el apartado de resultados y discusión, se analizan los datos obtenidos, estableciendo diversas conclusiones en relación al objetivo planteado; viendo que el cuestionario POMS resultó válido y sensible, las escalas EVA-fatiga, RPE y SEES-fatiga cumplieron los requisitos de facilidad de uso, validez y sensibilidad al trabajo efectuado. AbstractAthletes participating in the Rally-raid Dakar must show their competence to respond to a long-term effort in­volving psychological and physiological limiting factors due to the accumulated fatigue during the effort. The objective of this research was to analyze the suitability of different instruments to evaluate the fatigue perception of motorcyclists in competition. The research design is single case, with one participant (motorcyclist). The study consisted of two training sessions that were devel­oped in a circuit simulating the conditions of distance and difficulty of a stage. The instruments were the POMS questionnaire (McNair et al., 1971), the RPE-Borg scale (Borg, 1982) for the re­cording of perceived effort, VAS-fatigue scale (Lee et al., 1991), and SEES (McAuley & Cour­neya, 1994) for assessing the fatigue perception. In the results and discussion section, we analyze the data ob­tained, establishing different conclusions in relation to the objective set. The POMS questionnaire was valid and sensitive, the VAS-fatigue, RPE and SEES-fatigue scales met the ease of use, validity and sensitivity requirements to the study performed.
Resíduos de saúde no brasil e drogas ilícitas: uma visão interdisciplinar
Authors: Costa Sandro Luiz da , Soares Maria José Nascimento , Pessoa Flávia Moreira Guimarães
Published: August 2017

O descarte de drogas ilícitas no Brasil ocorre com impactos negativos ambientais, de saúde e de segurança. O objetivo do presente trabalho é expor o sistema jurídico-ambiental brasileiro de gestão de resíduos sólidos em geral e dos resíduos sólidos de saúde, exatamente para demonstrar o processo de disposição final ambientalmente adequado destes resíduos ou rejeitos, obtendo-se assim, um parâmetro para identificação da gravidade dos riscos ambientais inerentes ao incorreto descarte de drogas ilícitas, já que há lacuna na legislação brasileira sobre a correta disposição de resíduos gerados pelo uso de drogas legais ou ilegais pela pessoa física. Será utilizada uma abordagem sistêmica para a análise do presente tema, valendo-se da interdisciplinaridade que articule saberes do direito, da engenharia sanitária, da educação básica e da saúde, convergentes para um modelo de sustentabilidade ambiental.
Projeto do sistema de freios para um protótipo de Fórmula SAE Elétrico
Authors: Dória Ãcaro da Silva , Santos Antônio José de Jesus
Published: August 2017

Embasada no campo da Engenharia Mecânica com ênfase na dinâmica veicular, esta investigação objetiva o dimensionamento e modelagem computacional do sistema de freios para um veículo monoposto tipo fórmula de alto desempenho, atendendo todas as normas exigidas pela SAE International. Um freio funciona graças ao atrito resultante do contato entre um elemento não rotativo do veículo e um disco ou tambor que gira com a roda. O atrito produz a força necessária para reduzir a velocidade do automóvel ao converter em calor que se dissipa no ar a energia mecânica do veículo. (COSTA, 2002.) O sistema de freios é um componente essencial ao veículo, um item de segurança indispensável, mas pouco lembrado, só naqueles momentos cruciais pelos quais ninguém gostaria de passar. O seu incorreto dimensionamento acarretará em resultados não muito agradáveis, trata-se de um sistema que não permite falhas. O trabalho desenvolvido qualifica-se quanto a natureza, como do tipo pesquisa aplicada e como motivação, a necessidade de produzir conhecimento para aplicação de seus resultados, com o objetivo de construir para fins práticos (BARROS; LEHFELD, 1989). Foram analisados materiais referentes à dinâmica veicular e foi possível desenvolver uma ferramenta bastante prática para os projetistas de freios, um dimensionador para sistemas de freios de veículos monopostos. Para o seu funcionamento é necessário que o projetista forneça os dados iniciais de projeto (peso do veículo, altura, largura...) que o programa realiza os cálculos e retorna com o sistema dimensionado. A pesquisa se baseia nos conceitos da dinâmica veicular (GILLESPIE, 1992) e no projeto de freios (LIMPERT, 1999). Esta pesquisa justifica-se pela carência de trabalhos relacionados ao dimensionamento de freios para veículos monopostos em âmbito nacional. Todo o estudo desenvolvido pode ser utilizado no dimensionamento de sistema de freios para outros tipos de veículos, de maior ou menor porte.
Relación espacial entre nopales y madrigueras de rata magueyera Neotoma leucodon en Mapimí, México
Authors: De Haro-Guijarro Sergio , Martínez-Gutiérrez P. Guadalupe
Published: August 2017

For White-toothed Woodrat (Neotoma leucodon Merriam, 1894), a short distance between burrows and food source (prickly pear cacti Opuntia spp.), and long between competitors (neighbour burrows), would allow spend less time to feed by decreasing of linked costs of the predation and intraspecific competition, and more time to improve fitness. That distance relation might affect site selection to build or inhabiting a burrow, but it would rely on prickly pear cacti density. In this study, we describe and quantify, for the first time, the distance relations between Prickly-pears and White-toothed Woodrat burrows in Mapimí, Mexico. We compared burrow-prickly pear cactus and burrow-burrow distances in two places with different prickly pear cacti density (Nopalera-higher density, Playa-lower density). We found no correlation between these two distances, they were shorter in Nopalera, and burrowprickly pear cactus distances were shorter than burrow-burrow distances in both sites. We confirm that: a) there is a relation of distances between White-toothed Woodrat burrows and prickly –pear cacti affected by prickly pear cacti density, b) both burrow-prickly pear cactus and burrow-burrow distances are independent between themselves, and c) probably, burrow-prickly pear cactus distance is a more important selection place variable than burrow-burrow to build a new burrow or inhabiting an old one. White-toothed Woodrats of Nopalera could spend more time to improve fitness than these one of Playa, but it should be confirmed by field work. In addition, we discuss other points of the White-toothed Woodrats ecology in Mapimí.
Electrical activity controls area-specific expression of neuronal apoptosis in the mouse developing cerebral cortex
Authors: Blanquie Oriane , Yang Jenq-Wei , Kilb Werner , Sharopov Salim , Sinning Anne , Luhmann Heiko J
Published: August 2017

Programmed cell death widely but heterogeneously affects the developing brain, causing the loss of up to 50% of neurons in rodents. However, whether this heterogeneity originates from neuronal identity and/or network-dependent processes is unknown. Here, we report that the primary motor cortex (M1) and primary somatosensory cortex (S1), two adjacent but functionally distinct areas, display striking differences in density of apoptotic neurons during the early postnatal period. These differences in rate of apoptosis negatively correlate with region-dependent levels of activity. Disrupting this activity either pharmacologically or by electrical stimulation alters the spatial pattern of apoptosis and sensory deprivation leads to exacerbated amounts of apoptotic neurons in the corresponding functional area of the neocortex. Thus, our data demonstrate that spontaneous and periphery-driven activity patterns are important for the structural and functional maturation of the neocortex by refining the final number of cortical neurons in a region-dependent manner.
Assessing the utility of urinary and fecal cortisol as an indicator of stress in golden snub-nosed monkeys (Rhinopithecus roxellana)
Authors: Chen Haochun , Yao Hui , Yang Wanji , Fan Penglai , Xiang Zuofu
Published: August 2017

Cortisol concentration (CC) is often used as a stress indicator in animals, as high CC is associated with elevated stress levels. During field research, non-invasive methods of measuring CC, such as collection of urine and feces, are superior to using blood samples when monitoring free-ranging animals’ stress levels. However, due to different metabolic pathways, whether CC can be detected in urine and feces to reliably assess stress varies across species. Therefore, it is important to ascertain whether urine and fecal samples are a reliable source for determining CCs and to determine a suitable sampling regime. In this study, we subjected three captive adult golden snub-nosed monkeys (Rhinopithecus roxellana) to a high-stress situation (capture and injection). Urine and feces were collected for four days before and for four days after the manipulations for laboratory analysis. Immunoreactive CC was detected with a commercial enzyme immunoassay (EIA) kit and showed distinct rises. Peak CC values in urine were detected within 5 h, while peak fecal CC ranged between 5 and 24 hours post-interference. These results provide evidence that CC in urine and feces can be used to assess stress levels in the golden snub-nosed monkey. The optimal time frame to collect urinary and fecal samples for CC analysis is within one day of a potential stressful event.
RNA‐editing enzymes ADAR1 and ADAR2 coordinately regulate the editing and expression of Ctn RNA
Authors: Anantharaman Aparna , Gholamalamdari Omid , Khan Abid , Yoon Je‐Hyun , Jantsch Michael F. , Hartner Jochen C. , Gorospe Myriam , Prasanth Supriya G. , Prasanth Kannanganattu V.
Published: August 2017

Adenosine deaminases acting on RNA (ADARs) are proteins that catalyse widespread A‐to‐I editing within RNA sequences. We recently reported that ADAR2 edits and stabilizes nuclear‐retained Cat2 transcribed nuclear RNA (Ctn RNA). Here, we report that ADAR1 coordinates with ADAR2 to regulate editing and stability of Ctn RNA. We observe an RNA‐dependent interaction between ADAR1 and ADAR2. Furthermore, ADAR1 negatively regulates interaction of Ctn RNA with RNA‐destabilizing proteins. We also show that breast cancer (BC) cells display elevated ADAR1 but not ADAR2 levels, compared to nontumourigenic cells. Additionally, BC patients with elevated levels of ADAR1 show low survival. Our findings provide insights into overlapping substrate preferences of ADARs and potential involvement of ADAR1 in BC.
Crustal thickness and Poisson's ratio in southwest China based on data from dense seismic arrays
Authors: Wang Weilai , Wu Jianping , Fang Lihua , Lai Guijuan , Cai Yan
Published: August 2017

Crustal thickness and Poisson's ratio are important parameters to characterize regional isostasy state and material composition or state. Using the teleseismic waveform data from 141 permanent stations and 785 temporary stations in southwest China, we obtain the crustal thickness and average Poisson's ratio by theH‐κstacking of receiver functions. In the west (the SE Tibetan Plateau and the Yunnan‐Burma‐Thailand block) and southeast (the Cathaysian block and southern Yangtze craton) of the study region, there are high correlation coefficients for the crustal thicknesses between what we obtain from the receiver functions and what we calculate from the Airy isostasy model, indicating that a state of isostasy can be achieved at the crust‐mantle boundary beneath these two regions. In the northeast (northern Yangtze craton), the correlation coefficient is lower, indicating that the effect of the lithosphere needs to be considered for a regional isostasy. Intermediate Poisson's ratios (0.26 ≤ σ ≤ 0.28) are found beneath the northern Panzhihua‐Emeishan region. Combing the high‐velocity features from previous study, we speculate that it may be related to the Emeishan large igneous province. High Poisson's ratios (σ > 0.28) are found beneath the SE Tibetan Plateau and the nearby strike‐slip faults, such as the Anninghe‐Zemuhe fault and the northern Xiaojiang fault. Combing the low‐velocity zones from previous study, we speculate that there may be partially melted and lower crustal flow.
A case study of convectively sourced water vapor observed in the overworld stratosphere over the United States
Authors: Smith Jessica B. , Wilmouth David M. , Bedka Kristopher M. , Bowman Kenneth P. , Homeyer Cameron R. , Dykema John A. , Sargent Maryann R. , Clapp Corey E. , Leroy Stephen S. , Sayres David S. , Dean‐Day Jonathan M. , Paul Bui T. , Anderson James G.
Published: August 2017

On 27 August 2013, during the Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys field mission, NASA's ER‐2 research aircraft encountered a region of enhanced water vapor, extending over a depth of approximately 2 km and a minimum areal extent of 20,000 km2 in the stratosphere (375 K to 415 K potential temperature), south of the Great Lakes (42°N, 90°W). Water vapor mixing ratios in this plume, measured by the Harvard Water Vapor instrument, constitute the highest values recorded in situ at these potential temperatures and latitudes. An analysis of geostationary satellite imagery in combination with trajectory calculations links this water vapor enhancement to its source, a deep tropopause‐penetrating convective storm system that developed over Minnesota 20 h prior to the aircraft plume encounter. High resolution, ground‐based radar data reveal that this system was composed of multiple individual storms, each with convective turrets that extended to a maximum of ~4 km above the tropopause level for several hours. In situ water vapor data show that this storm system irreversibly delivered between 6.6 kt and 13.5 kt of water to the stratosphere. This constitutes a 20–25% increase in water vapor abundance in a column extending from 115 hP to 70 hPa over the plume area. Both in situ and satellite climatologies show a high frequency of localized water vapor enhancements over the central U.S. in summer, suggesting that deep convection can contribute to the stratospheric water budget over this region and season.
Rapid northward shift of the Indian Monsoon on the Tibetan Plateau at the end of the Little Ice Age
Authors: Zhang Xiaolong , Xu Baiqing , Günther Franziska , Witt Roman , Wang Mo , Xie Ying , Zhao Huabiao , Li Jiule , Gleixner Gerd
Published: August 2017

Variations in the Indian Monsoon (IM) and Westerlies (WS) significantly affect the climate on the Tibetan Plateau (TP) and have widespread ecological and socioeconomic impacts on the whole of Asian society. So far, however, the rate and magnitude of changes in the IM have still remained unclear. Here we report for the first time that the IM rapidly shifted northward at the end of the Little Ice Age (LIA). We used sediment proxies for humidity and moisture sources from the Taro Co Lake, which is located in the transition zone between the WS and IM. Our comprehensive survey of climate records for the TP and its peripheral mountain ranges revealed that the northern boundary of the IM (i.e., the southern boundary of the WS) lay along the southern slope of the Gandise Range (~29.5°N) in the late LIA. In contrast, it passed quickly over the Gandise Range by at least 1.5° in latitude at the end of the LIA. Our results suggest that this rapid climatic shift was potentially triggered by the counteracting effects of blocking by the TP and its marginal orography, which hindered the northward movement of the IM, and the pulling thermal gradient of the TP.
The environment of aggregated deep convection
Authors: Tsai Wei‐Ming , Wu Chien‐Ming
Published: August 2017

In this study, the environment of aggregated deep convection is investigated using a vector vorticity equation cloud‐resolving model (VVM). Idealized experiments are performed under various environmental moisture with or without imposed vertical wind shear. Convective aggregation is then evaluated through diagnosing the 3‐D size of an individual cloud from the model output using a six‐connected segmentation method. The aggregated convection is recognized by a distinct mode with larger size in the cloud‐size distribution. The results suggest that aggregated convection tends to develop when column relative humidity (CRH) is larger than 80% (67%) in nonshear (shear) cases. In addition, the degree of aggregation further increases with the increase of CRH. This aggregation process may be caused by an increasing probability of multicellular cloud structure under a moister environment. The results also suggest that there are at least five convective cores of such system. Analyses of precipitation distribution suggest that the most extreme instantaneous grid point precipitation mainly occurs within the largest convective clusters.
Towards seamless large‐domain parameter estimation for hydrologic models
Authors: Mizukami Naoki , Clark Martyn P. , Newman Andrew J. , Wood Andrew W. , Gutmann Ethan D. , Nijssen Bart , Rakovec Oldrich , Samaniego Luis
Published: August 2017

Estimating spatially distributed parameters remains one of the biggest challenges for large‐domain hydrologic modeling. Many large‐domain modeling efforts rely on spatially inconsistent parameter fields, e.g., patchwork patterns resulting from individual basin calibrations, parameter fields generated through default transfer functions that relate geophysical attributes to model parameters, or spatially constant, default parameter values. This paper provides an initial assessment of a multiscale parameter regionalization (MPR) method over large geographical domains to derive seamless parameters in a spatially consistent manner. MPR applies transfer functions at the native scale of the geophysical data, and then scales these model parameters to the desired model resolution. We developed a stand‐alone framework called MPR‐flex for multimodel use and applied MPR‐flex to the variable infiltration capacity model to produce hydrologic simulations over the contiguous United States (CONUS). We first independently calibrate 531 basins across CONUS to obtain a performance benchmark for each basin. To derive the CONUS parameter fields, we perform a joint MPR calibration using all but the poorest behaved basins to obtain a single set of transfer function parameters that are applied to the entire CONUS. Results show that CONUS‐wide calibration has similar performance compared to previous simulations using a patchwork quilt of partially calibrated parameter sets, but without the spatial discontinuities in parameters that characterize some previous CONUS‐domain model simulations. Several avenues to improve CONUS‐wide calibration remain, including selection of calibration basins, objective function formulation, as well as MPR‐flex improvements including transfer function formulations and scaling operator optimization.
A stable computation of log‐derivatives from noisy drawdown data
Authors: Ramos Gustavo , Carrera Jesus , Gómez Susana , Minutti Carlos , Camacho Rodolfo
Published: August 2017

Pumping tests interpretation is an art that involves dealing with noise coming from multiple sources and conceptual model uncertainty. Interpretation is greatly helped by diagnostic plots, which include drawdown data and their derivative with respect to log‐time, called log‐derivative. Log‐derivatives are especially useful to complement geological understanding in helping to identify the underlying model of fluid flow because they are sensitive to subtle variations in the response to pumping of aquifers and oil reservoirs. The main problem with their use lies in the calculation of the log‐derivatives themselves, which may display fluctuations when data are noisy. To overcome this difficulty, we propose a variational regularization approach based on the minimization of a functional consisting of two terms: one ensuring that the computed log‐derivatives honor measurements and one that penalizes fluctuations. The minimization leads to a diffusion‐like differential equation in the log‐derivatives, and boundary conditions that are appropriate for well hydraulics (i.e., radial flow, wellbore storage, fractal behavior, etc.). We have solved this equation by finite differences. We tested the methodology on two synthetic examples showing that a robust solution is obtained. We also report the resulting log‐derivative for a real case.
Using First‐Principles Calculations for the Advancement of Materials for Rechargeable Batteries
Authors: Yoon Gabin , Kim Do‐Hoon , Park Inchul , Chang Donghee , Kim Byunghoon , Lee Byungju , Oh Kyungbae , Kang Kisuk
Published: August 2017

Rechargeable batteries have been regarded as leading candidates for energy storage systems to satisfy soaring energy demands and ensure efficient energy use, and intensive efforts have thus been focused on enhancing their energy densities and power capabilities. First‐principles calculations based on quantum mechanics have played an important role in obtaining a fundamental understanding of battery materials, thus providing insights for material design. In this feature article, the theoretical approaches used to determine key battery properties, such as the voltage, phase stability, and ion‐diffusion kinetics, are reviewed. Moreover, the recent contribution of first‐principles calculations to the interpretation of complicated experimental characterization measurements on battery materials, such as those obtained using X‐ray absorption spectroscopy, electron energy‐loss spectroscopy, nuclear magnetic resonance spectroscopy, and transmission electron microscopy, are introduced. Finally, perspectives are provided on the research direction of first‐principles calculations for the development of advanced batteries, including the further development of theories that can accurately describe the dissolved species, amorphous phases, and surface reactions that are integral to the operation of future battery systems beyond Li‐ion batteries.
Metal Thio‐ and Selenophosphates as Multifunctional van der Waals Layered Materials
Authors: Susner Michael A. , Chyasnavichyus Marius , McGuire Michael A. , Ganesh Panchapakesan , Maksymovych Petro
Published: August 2017

Since the discovery of Dirac physics in graphene, research in 2D materials has exploded with the aim of finding new materials and harnessing their unique and tunable electronic and optical properties. The follow‐on work on 2D dielectrics and semiconductors has led to the emergence and development of hexagonal boron nitride, black phosphorus, and transition metal disulfides. However, the spectrum of good insulating materials is still very narrow. Likewise, 2D materials exhibiting correlated phenomena such as superconductivity, magnetism, and ferroelectricity have yet to be developed or discovered. These properties will significantly enrich the spectrum of functional 2D materials, particularly in the case of high phase‐transition temperatures. They will also advance a fascinating fundamental frontier of size and proximity effects on correlated ground states. Here, a broad family of layered metal thio(seleno)phosphate materials that are moderate‐ to wide‐bandgap semiconductors with incipient ionic conductivity and a host of ferroic properties are reviewed. It is argued that this material class has the potential to merge the sought‐after properties of complex oxides with electronic functions of 2D and quasi‐2D electronic materials, as well as to create new avenues for both applied and fundamental materials research in structural and magnetic correlations.
Strategies for Improving the Functionality of Zeolitic Imidazolate Frameworks: Tailoring Nanoarchitectures for Functional Applications
Authors: Kaneti Yusuf Valentino , Dutta Saikat , Hossain Md. S. A. , Shiddiky Muhammad J. A. , Tung Kuo‐Lun , Shieh Fa‐Kuen , Tsung Chia‐Kuang , Wu Kevin C.‐W. , Yamauchi Yusuke
Published: August 2017

Zeolitic imidazolate frameworks (ZIFs), a subclass of metal–organic frameworks (MOFs) built with tetrahedral metal ions and imidazolates, offer permanent porosity and high thermal and chemical stabilities. While ZIFs possess some attractive physical and chemical properties, it remains important to enhance their functionality for practical application. Here, an overview of the extensive strategies which have been developed to improve the functionality of ZIFs is provided, including linker modifications, functional hybridization of ZIFs via the encapsulation of guest species (such as metal and metal oxide nanoparticles and biomolecules) into ZIFs, and hybridization with polymeric matrices to form mixed matrix membranes for industrial gas and liquid separations. Furthermore, the developed strategies for achieving size and shape control of ZIF nanocrystals are considered, which are important for optimizing the textural characteristics as well as the functional performance of ZIFs and their derived materials/hybrids. Moreover, the recent trends of using ZIFs as templates for the derivation of nanoporous hybrid materials, including carbon/metal, carbon/oxide, carbon/sulfide, and carbon/phosphide hybrids, are discussed. Finally, some perspectives on the potential future research directions and applications for ZIFs and ZIF‐derived materials are offered.
Globularity‐Selected Large Molecules for a New Generation of Multication Perovskites
Authors: Gholipour Somayeh , Ali Abdollah Morteza , Correa‐Baena Juan‐Pablo , Turren‐Cruz Silver‐Hamill , Tajabadi Fariba , Tress Wolfgang , Taghavinia Nima , Grätzel Michael , Abate Antonio , De Angelis Filippo , Gaggioli Carlo Alberto , Mosconi Edoardo , Hagfeldt Anders , Saliba Michael
Published: August 2017

Perovskite solar cells (PSCs) use perovskites with an APbX3 structure, where A is a monovalent cation and X is a halide such as Cl, Br, and/or I. Currently, the cations for high‐efficiency PSCs are Rb, Cs, methylammonium (MA), and/or formamidinium (FA). Molecules larger than FA, such as ethylammonium (EA), guanidinium (GA), and imidazolium (IA), are usually incompatible with photoactive “black”‐phase perovskites. Here, novel molecular descriptors for larger molecular cations are introduced using a “globularity factor”, i.e., the discrepancy of the molecular shape and an ideal sphere. These cationic radii differ significantly from previous reports, showing that especially ethylammonium (EA) is only slightly larger than FA. This makes EA a suitable candidate for multication 3D perovskites that have potential for unexpected and beneficial properties (suppressing halide segregation, stability). This approach is tested experimentally showing that surprisingly large quantities of EA get incorporated, in contrast to most previous reports where only small quantities of larger molecular cations can be tolerated as “additives”. MA/EA perovskites are characterized experimentally with a band gap ranging from 1.59 to 2.78 eV, demonstrating some of the most blue‐shifted PSCs reported to date. Furthermore, one of the compositions, MA0.5EA0.5PbBr3, shows an open circuit voltage of 1.58 V, which is the highest to date with a conventional PSC architecture.
Modulation of Multiscale 3D Lattices through Conformational Control: Painting Silk Inverse Opals with Water and Light
Authors: Wang Yu , Aurelio Daniele , Li Wenyi , Tseng Peter , Zheng Zhaozhu , Li Meng , Kaplan David L. , Liscidini Marco , Omenetto Fiorenzo G.
Published: August 2017

Structural proteins from naturally occurring materials are an inspiring template for material design and synthesis at multiple scales. The ability to control the assembly and conformation of such materials offers the opportunity to define fabrication approaches that recapitulate the dimensional hierarchy and structure–function relationships found in nature. A simple and versatile directed assembly method of silk fibroin, which allows the design of structures across multiple dimensional scales by generating and tuning structural color in large‐scale, macro defect‐free colloidally assembled 3D nanostructures in the form of silk inverse opals (SIOs) is reported. This approach effectively combines bottom‐up and top‐down techniques to obtain control on the nanoscale (through silk conformational changes), microscale (through patterning), and macroscale (through colloidal assembly), ultimately resulting in a controllable photonic lattice with predefined spectral behavior, with a resulting palette spanning almost the entire visible range. As a demonstration of the approach, examples of “multispectral” SIOs, paired with theoretical calculations and analysis of their response as a function of changes of lattice constants and refractive index contrast are illustrated.
Self‐Templated Fabrication of MoNi4/MoO3‐x Nanorod Arrays with Dual Active Components for Highly Efficient Hydrogen Evolution
Authors: Chen Yu‐Yun , Zhang Yun , Zhang Xing , Tang Tang , Luo Hao , Niu Shuai , Dai Zhi‐Hui , Wan Li‐Jun , Hu Jin‐Song
Published: August 2017

A binder‐free efficient MoNi4/MoO3‐x nanorod array electrode with 3D open structure is developed by using Ni foam as both scaffold and Ni source to form NiMoO4 precursor, followed by subsequent annealing in a reduction atmosphere. It is discovered that the self‐templated conversion of NiMoO4 into MoNi4 nanocrystals and MoO3‐x as dual active components dramatically boosts the hydrogen evolution reaction (HER) performance. Benefiting from high intrinsic activity, high electrochemical surface area, 3D open network, and improved electron transport, the resulting MoNi4/MoO3‐x electrode exhibits a remarkable HER activity with extremely low overpotentials of 17 mV at 10 mA cm−2 and 114 mV at 500 mA cm−2, as well as a superior durability in alkaline medium. The water–alkali electrolyzer using MoNi4/MoO3‐x as cathode achieves stable overall water splitting with a small cell voltage of 1.6 V at 30 mA cm−2. These findings may inspire the exploration of cost‐effective and efficient electrodes by in situ integrating multiple highly active components on 3D platform with open conductive network for practical hydrogen production.
Polymer Microstructures through Two‐Photon Crosslinking
Authors: Schwärzle David , Hou Xiaoqang , Prucker Oswald , Rühe Jürgen
Published: August 2017

Two‐photon crosslinking of polymers (2PC) is proposed as a novel method for the fabrication of freestanding microstructures via two‐photon lithography. During this process in the confocal volume, two‐photon absorption leads to (formal) C,H‐insertion reactions, and consequently to a strictly localized crosslinking of the polymer. To achieve this, the polymer is coated as a solvent‐free (glassy) film onto an appropriate substrate, and the desired microstructure is written by 2PC into this glass. In all regions outside of the focal volume where no two‐photon process occurs, the polymer remains uncrosslinked and can be washed away during a developing process. Using a self‐assembled monolayer containing the same photoreactive group allows covalent attachment of the forming freestanding structures to the substrate, and thus guarantees an improved stability of these structures against shear‐induced detachment. As the two photon process is carried out in the glassy state, in a simple way, multilayer structures can be used to write structures having a varying chemical composition perpendicular to the surface. As an example, the 2PC process is used to build a structure from both protein‐repellent and protein‐adsorbing polymers so that the resulting 3D structure exhibits spatially controlled protein adsorption.
Synthesis and surface properties of a novel fluorine modified acrylate colloid
Authors: Wang Xiuming , Xu Tingting , Zhang Cuifeng , Chen Lijun
Published: August 2017

The novel modified acrylate colloid was synthesized by semi‐continuous seeded emulsion polymerization which was initiated with potassium persulfate (KPS), and octylphenol polyoxyethylene ether (OP‐10) and sodium dodecyl benzene sulfonate (SDBS) were used as surfactants. Butyl acrylate (BA) and methyl methacrylate (MMA) were used as the main monomers and hexafluorobutyl methacrylate (HFMA, C8H8F6O2), and benzyl methacrylate (BZMA, C11H12O2) were used as functional monomers. Factors such as the amount of initiator, mass ratio of SDBD to OP‐10 and monomers, which have an influence on particle size and morphology of the resultant colloid, are studied. Chemical composition of the modified acrylate colloid was evaluated by Fourier transform infrared spectrometry (FTIR). The thermal performances were characterized by differential scanning calorimetry (DSC) and thermogravimetry (TG). Furthermore, surface hydrophobicity of the latex film was examined by measurement of water absorption and water contact angle. Results indicate that the modified acrylate colloid has highest monomer conversion rate and lowest coagulation percentage when the mass fraction of emulsifier was 4% and mass ratio of SDBS to OP‐10 was 1:2, mass fraction of initiator was 0.3%, mass percent of HFMA was 6%, and the amount of BZMA was 2%. Benzene ring‐containing monomer is effectively participated in the reaction and has improved the thermal performance and surface properties of copolymer colloid. The resultant colloid has excellent hydrophobicity and low surface energy. Solid content of the resultant colloid was about 30% (wt %).
Improvements in mechanical strength and thermal stability of injection and compression molded components based on Poly Lactic Acids
Authors: Aversa Clizia , Barletta Massimiliano , Gisario Annamaria , Pizzi Elisa , Puopolo Michela , Vesco Silvia
Published: August 2017

Degradable polymers are limited by their often‐insufficient mechanical and thermal properties, which limit their usage to single‐use packaging items at room temperature and in dry conditions. In this respect, the present work deals with the manufacture of custom‐built Poly Lactic Acids (PLAs), which are designed to be compostable, suitable for food contact and are characterized by a good compromise between mechanical properties and thermal stability. A commercial gradePLAwas, therefore, compounded in a twin‐screw co‐rotating extruder by the use of specific additives: maleated and glycidyl methacrylatePLAs as compatibilizers/chain extenders and microlamellar talc as mineral filler/nucleation promoter. After pelletizing, the resulting compounds were melt‐processed by injection and compression molding. Differential scanning calorimetry, flexural tests in static machine and top‐hat cylindrical flat indentations were performed to evaluate the thermal and mechanical response of the molded components. The experimental findings show that crystallization of thePLAcan be controlled by fine‐tuning the compound formulation as well as by properly setting the processing parameters. In addition, achievement of the appropriate crystallization degree in the polymer can lead to molded components, which exhibit improved mechanical strength and high thermal stability.
Contact dermatitis is an unrecognized problem in the construction industry: Comparison of four different assessment methods
Authors: Timmerman Johan G. , Heederik Dick , Spee Ton , van Rooy Frits G. , Krop Esmeralda J. M. , Rustemeyer Thomas , Smit Lidwien A. M.
Published: August 2017

Background

A high contact dermatitis symptoms prevalence has been observed in Dutch construction workers.

Methods

Contact dermatitis was diagnosed by an expert panel using questionnaire data and photographs of 751 subjects’ hands. A subset was evaluated by two occupational physicians. Their diagnoses were compared to those of the expert panel. In addition, two self‐reported questionnaire‐based assessment methods were compared to the expert panel evaluation. Associations between contact dermatitis and determinants were assessed using log‐binomial regression analysis.

Results

Contact dermatitis prevalence was high: 61.4% (expert panel's diagnosis) and 32.9% (self‐reported). Agreement between occupational physicians and the expert panel was low but increased after training. Washing hands with solvents and performing job‐related tasks at home were related to contact dermatitis.

Conclusions

Contact dermatitis prevalence among construction workers is high. Recognition of contact dermatitis by occupational physicians is poor but can be improved by training. Awareness of skin disorders should be raised.
Mortality in asbestos cement workers in Pavia, Italy: A cohort study
Authors: Oddone Enrico , Ferrante Daniela , Tunesi Sara , Magnani Corrado
Published: August 2017

Background

The aim of this study was to describe the mortality of a cohort of asbestos‐cement workers in the largest plant in the most industrialized Italian region (Lombardy).

Methods

A cohort study was carried out on 1818 subjects, corresponding to 47 536.1 person‐years of observation. Standardized mortality ratios (SMRs) were computed for the major causes of death.

Results

Increased SMRs were observed for pleural, peritoneal and lung cancers, and for asbestosis (SMR 26.73, 95% Confidence Interval (CI) 20.99‐33.55; 9.15, 95%CI 5.00‐15.34; 1.48, 95%CI 1.27‐1.72; and 368.05, 95%CI 214.40‐589.29, respectively). No excess in mortality for laryngeal cancer was observed (SMR 0.70, 95%CI 0.30‐1.39). An increased mortality for ovarian cancer (SMR 3.64, 95%CI 0.99‐9.33) was observed, although it was not statistically significant. Among men, mortality for pleural malignant mesothelioma was observed to be related to the duration of exposure, though not to latency.

Conclusions

The results of this study are generally consistent with present knowledge. Conversely, our results do not support the hypothesis that pleural malignant mesothelioma risk indefinitely increases after exposure, suggesting instead that the alternative hypothesis of a risk plateau or decrease after a time since first exposure of more than 40 years is more consistent with the observed data.