bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of mineral dust and sea spray supermicron particle concentrations and acidity on inorganic NO3− aerosol during the 2013 Southern Oxidant and Aerosol Study
Authors: Allen H. M. , Draper D. C. , Ayres B. R. , Ault A. , Bondy A. , Takahama S. , Modini R. L. , Baumann K. , Edgerton E. , Knote C. , Laskin A. , Wang B. , Fry J. L.
Published: May 2015

Abstract. The inorganic aerosol composition was measured in the southeastern United States, a region that exhibits high aerosol mass loading during the summer, as part of the 1 June to 15 July 2013 Southern Oxidant and Aerosol Study (SOAS) campaign. Measurements using a Monitor for AeRosols and GAses (MARGA), an ion chromatograph coupled with a wet rotating denuder and a steam-jet aerosol collector for monitoring of ambient inorganic gas and aerosol species, revealed two periods of high aerosol nitrate (NO3−) concentrations during the campaign. These periods of high nitrate were correlated with increased concentrations of coarse mode mineral or sea spray aerosol species, particularly Na+ and Ca2+, and with a shift towards aerosol with larger (1 to 2.5 μm) diameters. We suggest this nitrate aerosol forms by multiphase reactions of HNO3 and particles, reactions that are facilitated by transport of mineral dust and sea spray aerosol from a source within the United States. The observed high aerosol acidity prevents the formation of NH4NO3, the inorganic nitrogen species often dominant in fine-mode aerosol at higher pH. Calculation of the rate of the heterogeneous uptake of HNO3 on mineral aerosol supports the conclusion that aerosol NO3− is produced primarily by this process, and is likely limited by the availability of mineral dust surface area. Modeling of NO3− and HNO3 by thermodynamic equilibrium models (ISORROPIA II and E-AIM) reveals the importance of including mineral cations in the southeastern United States to accurately balance ion species and predict gas/aerosol phase partitioning.
Local and regional scale measurements of CH4, δ13CH4, and C2H6 in the Uintah Basin using a mobile stable isotope analyzer
Authors: Rella C. W. , Hoffnagle J. , He Y. , Tajima S.
Published: May 2015

Abstract. In this paper, we present an innovative CH4, δ13CH4, and C2H6 instrument based on cavity ring down spectroscopy (CRDS). The design and performance of the analyzer is presented in detail. The instrument is highly precise, capable of precision of less than 1‰ on δ13CH4 with 1 min of averaging and about 0.1‰ in an hour. Using this instrument, we present a comprehensive approach to atmospheric methane emissions attribution. Field measurements were performed in the Uintah Basin (Utah, USA) in the winter of 2013, using a mobile lab equipped with the CRDS analyzer, a high-accuracy GPS, a sonic anemometer, and a novel onboard gas storage and playback system. With a small population and almost no other sources of methane and ethane other than oil and gas extraction activities, the Uintah Basin represents an ideal location to investigate and validate new measurement methods of atmospheric methane and ethane. We present the results of measurements of the individual fugitive emissions from 23 natural gas wells and 6 oil wells in the region. The δ13CH4 and C2H6 signatures that we observe are consistent with the signatures present in the ground. Furthermore, regional measurements of the atmospheric CH4, δ13CH4, and C2H6 signatures throughout the basin have been made, using continuous sampling into a 450 m long tube. These measurements suggest that 86 ± 7% of the total emissions in the basin are from natural gas production.
A collection of sub-daily pressure and temperature observations for the early instrumental period with a focus on the "year without a summer" 1816
Authors: Brugnara Y. , Auchmann R. , Brönnimann S. , Allan R. J. , Auer I. , Barriendos M. , Bergström H. , Bhend J. , Brázdil R. , Compo G. P. , Cornes R. C. , Dominguez-Castro F. , van Engelen A. F. V. , Filipiak J. , Holopainen J. , Jourdain S. , Kunz M. , Luterbacher J. , Maugeri M. , Mercalli L. , Moberg A. , Mock C. J. , Pichard G. , Řezníčková L. , van der Schrier G. , Slonosky V. , Ustrnul Z. , Valente M. A. , Wypych A. , Yin X.
Published: May 2015

Abstract. The eruption of Mount Tambora (Indonesia) in April 1815 is the largest documented volcanic eruption in history. It caused a large global cooling during the following year, felt particularly in parts of Europe and North America, where the year 1816 became known as the "year without a summer". This paper describes an effort made to collect surface meteorological observations from the early instrumental period, with a focus on the years immediately following the eruption (1815–1817). Although the collection aimed in particular at pressure observations, correspondent temperature observations were also recovered. Some of the series had already been described in the literature, but a large part of the data, recently digitised from original weather diaries and contemporary magazines and newspapers, is presented here for the first time. The collection puts together more than fifty sub-daily series from land observatories in Europe and North America, and from ships in the tropics. The pressure observations have been corrected for temperature and gravity and reduced to mean sea level, moreover an additional statistical correction was applied to take into account common error sources in mercury barometers. To assess the reliability of the corrected dataset, the variance of the pressure observations is compared with modern climatologies and single observations are used for synoptic analyses of three case studies in Europe. All raw observations will be made available to the scientific community in the International Surface Pressure Databank.
The question of Sudan: a hydro-economic optimization model for the Sudanese Blue Nile
Authors: Satti S. , Zaitchik B. , Siddiqui S.
Published: May 2015

Abstract. The effects of development and the uncertainty of a changing climate in eastern Africa pose myriad challenges for water managers along the Blue Nile. Sudan's large irrigation potential, hydroelectric dams, and prime location within the basin mean that Sudan's water management decisions will have great social, economic and political implications for the region. At the same time, Sudan's water use options are constrained by tradeoffs between upstream irrigation developments and downstream hydropower facilities as well as by the country's commitments under existing or future transboundary water sharing agreements. Here, we present a model that can be applied to evaluate optimal allocation of surface water resources to irrigation and hydropower in the Sudanese portion of the Blue Nile. Hydrologic inputs are combined with agronomic and economic inputs to formulate an optimization model within the General Algebraic Modeling System (GAMS). A sensitivity analysis is performed by testing model response to a range of economic conditions and to changes in the volume and timing of hydrologic flows. Results indicate that changing hydroclimate inputs have the capacity to greatly influence the productivity of Sudan's water resource infrastructure. Results also show that the economically optimal volume of water consumption, and thus the importance of existing treaty constraints, is sensitive to the perceived value of agriculture relative to electricity as well as to changing hydrological conditions.
AN AUTOMATIC 3D RECONSTRUCTION METHOD BASED ON MULTI-VIEW STEREO VISION FOR THE MOGAO GROTTOES
Authors: Xiong J. , Zhong S. , Zheng L.
Published: May 2015

Abstract. This paper presents an automatic three-dimensional reconstruction method based on multi-view stereo vision for the Mogao Grottoes. 3D digitization technique has been used in cultural heritage conservation and replication over the past decade, especially the methods based on binocular stereo vision. However, mismatched points are inevitable in traditional binocular stereo matching due to repeatable or similar features of binocular images. In order to reduce the probability of mismatching greatly and improve the measure precision, a portable four-camera photographic measurement system is used for 3D modelling of a scene. Four cameras of the measurement system form six binocular systems with baselines of different lengths to add extra matching constraints and offer multiple measurements. Matching error based on epipolar constraint is introduced to remove the mismatched points. Finally, an accurate point cloud can be generated by multi-images matching and sub-pixel interpolation. Delaunay triangulation and texture mapping are performed to obtain the 3D model of a scene. The method has been tested on 3D reconstruction several scenes of the Mogao Grottoes and good results verify the effectiveness of the method.
SELF-LOCALIZATION METHOD BY INTEGRATING SENSORS
Authors: Fuse T. , Matsumoto K.
Published: May 2015

Abstract. Recently, development of high performance CPU, cameras and other sensors on mobile devices have been used for wide variety of applications. Most of the applications require self-localization of the mobile device. Since the self-localization is based on GPS, gyro sensor, acceleration meter and magnetic field sensor (called as POS) of low accuracy, the applications are limited. On the other hand, self-localization method using images have been developed, and the accuracy of the method is increasing. This paper develops the self-localization method by integrating sensors, such as POS and cameras, on mobile devices simultaneously. The proposed method mainly consists of two parts: one is the accuracy improvement of POS data filtering, and another is development of self-localization method by integrating POS and camera. The POS data filtering combines all POS data by using Kalman filter in order to improve the accuracy of exterior orientation factors. The exterior orientation factors with POS filtering are used as initial value of ones in image-based self-localization method. The image-based self-localization method consists of feature points extraction and tracking, relative orientation, coordinates estimation of the feature points, and orientation factors updates of the mobile device. The proposed method is applied to POS data and images taken in urban area. Through experiments with real data, the accuracy improvement by POS data filtering is confirmed. The proposed self-localization method with POS and camera make the accuracy more sophisticated by comparing with only POS data filtering.
An electrical characterisation system for the real-time acquisition of multiple independent sensing parameters from organic thin film transistors
Authors: Dragoneas A. , Hague L. , Grell M.
Published: May 2015

Abstract. The presence of multiple independent sensing parameters in a single device is the key conceptual advantage of sensor devices based on an organic thin film transistor (OTFT) over simple organic chemiresistors. Practically, however, these multiple parameters must first be extracted from the electrical characteristics of the OTFTs and, thus, they are not immediately apparent. To exploit the advantage of OTFT sensors, we require a measurement technology to extract these parameters in real time. Here, we introduce an efficient, cost-effective system that is a faster and more compact alternative to the expensive and cumbersome laboratory-based instruments currently available. The characterisation system presented here records the electric behaviour of OTFTs in the form of its "saturated transfer characteristics" multiple times per second for virtually unlimited periods of time, with the option to multiplex up to 20 devices in parallel. By applying a bespoke algorithm to the measured transfer characteristics, the system then extracts, in real time, several underlying transistor parameters (on- and off-current, threshold voltage, and charge carrier mobility). Tests were conducted on the example of a poly(thieno[3,2-b]thiophene) (PBTTT) OTFT exposed to ethanol vapour. The system extracts the underlying OTFT parameters with very low noise without introducing apparent correlations between independent parameters as an artefact.
Análisis evolutivo del concepto adaptación a la diabetes tipo 2
Authors: Castro-Espinoza José Martín , Gallegos-Cabriales Esther C. , Frederickson Keville
Published: May 2015

El concepto de adaptación tiene diferentes aplicaciones y acepciones. En personas que viven con diabetes tipo 2 (DT2) se asocia con la observancia del tratamiento y el control glucémico. Es utilizado frecuentemente en la literatura de salud, pero no está claro qué significa en personas que viven con esta enfermedad, por lo que el propósito de esta investigación fue analizar el concepto de adaptación a la DT2. Metodología: se utilizó el método de análisis evolutivo de concepto de Rodgers. Los datos se codificaron por autor, 16 en total, palabras clave, hallazgos, antecedentes, atributos y consecuencias, conceptos relativos y sustitutos. La guía del análisis respondió a tres preguntas: ¿cómo define el concepto el autor? ¿Qué características o atributos se establecen? ¿Qué idea da el autor acerca del concepto? Resultados: el concepto de adaptación muestra atributos que permiten definirlo como un proceso que se presenta en tres fases: reacción, asimilación y respuesta. Los antecedentes corresponden a conductas previas al proceso, los resultados incluyen desafíos y cambios. Conclusiones: los atributos, los antecedentes y las consecuencias ofrecen guías para la investigación; es necesario ampliar el estudio en el contexto del hogar, la familia, el trabajo y el hospital.
Saint-Mamas, Strudel, and the Single Man in Arthur Miller'sDeath of a Salesman
Authors: Gleitman Claire
Published: May 2015

This article argues that Death of a Salesman takes as its context a tapestry of ideals about American manhood that developed in the eighteenth and nineteenth centuries and seeped into Willy's self-perception as uncritically absorbed articles of faith. These ideals prevent him from achieving fulfillment while stunting his sons' psychological growth. Willy's pantheon of male heroes includes his father, his brother Ben, and Dave Singleman, figures who have in common wanderlust, perfect self-reliance, and the freedom to thrive in an all-male universe. Willy and his sons cannot fulfill their culturally constructed understanding of masculine success without becoming, like Willy's male heroes, essentially if not literally single men. It is for this reason that the Loman men collapse women into two categories: they are either “strudel”—sexual objects to be consumed—or saintly mothers; both exist to prop up the male ideal, which, if fully achieved, permits the male to discard them.
The Rochester Amateurs and The Fall of the House of Usher
Authors: Brewer Charles E.
Published: May 2015

In 1928 James Sibley Watson, Jr. (former editor of The Dial), and Melville Webber (an art historian) created a silent film based on “The Fall of the House of Usher” in a Rochester, New York, carriage barn. Using published and previously unpublished documents, it is clear that this amateur film was intended to create a new visual adaptation and interpretation of Edgar Allan Poe's original story, rich in the modernist ambiguity of the early twentieth century. A member of this creative circle was a young and not very experienced composer, Alec Wilder. He was asked to create a new score for this film, but in the end his inability to perform it adequately and lack of confidence caused it to be suppressed. The rediscovery of Wilder's original avant-garde score provides evidence of how he was able to create a modernist composition to mirror the visual perspective of the film. In the mid-1950s, Wilder, by then a respected composer of popular songs, was approached by one of the actors in the original film, Hildegard Lasell Watson, to write a new score. This, written in his more lyrical and popular classical style and creating a more subtle reading of the film's ambiguities, was synchronized by Dr. Watson to create the authorized version. The film has continued to inspire other contemporary composers, such as Colin Z. Robertson and Iris ter Schiphorst, to create their own interpretations of Watson's and Webber's unique adaptation of Poe's tale.
Copyright Law and the Changing Economic Value of Popular Music in India
Authors: Booth Gregory
Published: May 2015

Using archival and ethnographic data, this study examines Indian understandings of music as intellectual property, as expressed in industrial logic and practice, in industrial, legal and public discourse and through the content of, and approaches to, the Indian Copyright Act. Those understandings were powerfully influenced by changing technology, market dynamics, and Indian relations with the world economy (after 1984). Collectively, these phenomena led to sometimes extreme changes in the nature and economic value of music commodities in India between 1970 and 2010, and, ultimately, to the Copyright (Amendment) Bill 2012, the "Bollywood" amendments.
Perceção dos pais em relação à inclusão de crianças com Necessidades Educativas Especiais no ensino regular
Authors: Freitas Elisabete Matos , Arroja Luísa Novais , Ribeiro Paula Magalhães , Dias Paulo César
Published: May 2015

O papel dos pais no processo de inclusão de crianças com necessidades educativas especiais é fundamental, seja no apoio familiar, desmontando mitos e criando um contexto favorável à experiência e à proximidade. O objetivo deste trabalho é, assim, conhecer as perceções dos pais relativamente à inclusão, assim como os factores que as influenciam. Para isso, foi aplicado um inquérito a 300 pais, com e sem filhos com necessidades educativas especiais. Os resultados permitiram perceber atitudes genericamente positivas, sem diferenças relativamente ao género e ao fato de serem pais de crianças com necessidades educativas especiais. Contudo as variáveis idade, escolaridade e proximidade / contato pareceram influenciar a perceção em relação a inclusão de crianças NEE. Assim, os pais com atitudes mais favoráveis à inclusão tendem a ser os mais novos, que tiveram proximidade / contato com criança NEE. Os resultados são discutidos em função da literatura.
Modelos e Diretrizes para uma Educação Inclusiva: Revisão de Literatura
Authors: Siqueira Maria das Graças Soares , Aguillera Fernanda
Published: May 2015

Apesar da inclusão escolar ser uma realidade na legislação brasileira, verifica-se no cotidiano das instituições de ensino regular, particulares e públicas, certa dificuldade em lidar com a adequação às demandas dos alunos especiais. Assim, o objetivo desse trabalho foi identificar pesquisas contendo diretrizes e modelos para promoção da inclusão escolar, que abarcassem a ação do psicólogo. Para tanto, realizou-se busca sistemática nas bases de dados da Biblioteca Virtual em Saúde (BVS-Psi), especificamente Lilacs, Scielo e Pepsic. Utilizando-se a palavra-chave inclusão escolar, obteve-se 390, 39 e 22 artigos, respectivamente. Como um número considerável de títulos fugia ao objetivo do trabalho, optou-se por restringir a busca com as palavras-chaves intervenção e inclusão escolar, resultando um total de 55 artigos. A partir da leitura de seus títulos e resumos, foram excluídos os trabalhos com temática em desacordo aos interesses da pesquisa (31) e em duplicidade (09), totalizando 15 artigos para análise. Como resultado verificou-se que de 2005 para cá houve uma crescente produção de trabalhos interventivos voltados para educação inclusiva, predominantemente na área da Psicologia, porém mais publicados em revistas de Educação Especial ou de Educação. Em sua maioria, dedicaram-se a um público etário de 04 a 16 anos, e as intervenções foram mais direcionadas a deficiências específicas ou não identificadas. Mas são raros os relatos de procedimentos e recomendações mais abrangentes, que sirvam de norteadores à prática nesse campo. Tais resultados sugerem lacunas na produção científica voltadas à apresentação de modelos inclusivos mais amplos, com a participação do psicólogo. Palavras-Chave: Inclusão escolar; Intervenção; Psicologia.
Discurso e mídia: construção de concepções da pessoa com deficiência intelectual em propagandas
Authors: Schipper Carla Maria de , Witzel Denise Gabriel
Published: May 2015

Este trabalho foi concebido com o intuito de compreendermos o trabalho da linguagem com relação à construção de concepções de Deficiência Intelectual na contemporaneidade e a gênese discursiva dessas, a partir da análise do discurso de propagandas veiculadas por uma instituição de educação especial no período de 1980 a 2009. Para realizar esta ação, utilizou-se como base teórica a Análise do Discurso (AD) de perspectiva francesa, sobretudo os conceitos de interdiscurso, memória e heterogeneidade. Anteriormente à análise, necessário se fez apresentar algumas noções basilares da AD e as diversas concepções de deficiência que surgiram ao longo da história. O material de análise é composto por cinco textos publicitários publicados em uma revista especializada que representa instituições voltadas ao atendimento da pessoa com deficiência intelectual e uma propaganda para arrecadação de recursos. O resgate da memória discursiva, considerando as condições sócio-históricas de produção, permitiu dar visibilidade às diferentes posições do sujeito Deficiente Intelectual na sociedade em cada momento relatado. Nos discursos enunciados, observaram-se estratégias de internalização de papéis sociais voltados à inclusão educacional, mas, no interdiscurso, revelaram-se discursos outros que sedimentam antigos paradigmas da medicalização e do trabalho como missão.
Yiwarra Kuju, ou comment l’espace a été transformé en lieu au National Museum of Australia
Authors: Carty John , Dorion-Coupal Karen
Published: May 2015

Yiwarra Kuju: The Canning Stock Route est l’exposition qui a remporté le plus de succès dans toute l’histoire du National Museum of Australia (NMA). Structurée autour de peintures du désert réalisées par des Aborigènes contemporains, l’exposition représente la tentative la plus importante du NMA d’honorer les concepts, les valeurs et les voix aborigènes au moyen d’une exposition. En racontant l’histoire coloniale avec une perspective aborigène et en proposant aux visiteurs une expérience culturelle complexe dans le cadre d’une exposition d’art, Yiwarra Kuju… explorait des terrains inconnus de la muséologie. En effet, l’idée même d’« exposition » a été remise en question et transformée par un processus de conservation collaboratif et transculturel. Toutefois, l’acte collaboratif le plus important, préalable à Yiwarra Kuju…, a été de prendre au sérieux les artistes aborigènes ainsi que le défi conceptuel que représentait leur travail, tout en donnant à l’art aborigène l’espace institutionnel nécessaire pour remettre en question les conventions et les présupposés qui sous-tendent les approches muséales envers la culture matérielle et le patrimoine immatériel indigènes. Yiwarra Kuju… a testé différentes frontières dans l’approche muséale de l’art aborigène et de l’histoire australienne. Dans cet article, j’explore les défis conceptuels, politiques et méthodologiques uniques qui ont défini le processus de conservation.
Un Wendat nomade sur la piste des musées
Authors: Sioui Durand Guy
Published: May 2015

Au regard des Amérindiens, le musée est-il à éviter ? Pour répondre à cette question, l’auteur avance une mutation du paradigme de « l’Indien inventorié », largement hérité des visions colonialistes du monde, et y oppose la notion defait total d’Américitécomme point d’ancrage amérindien. S’ensuit un survol des avancées muséologiques tant de la part des grands musées urbains que des communautés sur les terres de réserve. Une hypothèse d’exposition comme archive vivante mettant à profit le recours à l’art autochtone contemporain sert de conclusion.
Field line distribution of mass density at geostationary orbit
Authors: Denton R. E. , Takahashi Kazue , Lee Jinmyoung , Zeitler C. K. , Wimer N. T. , Litscher L. E. , Singer H. J. , Min Kyungguk
Published: May 2015

The distribution of mass density along the field lines affects the ratios of toroidal (azimuthally oscillating) Alfvén frequencies, and given the ratios of these frequencies, we can get information about that distribution. Here we assume the commonly used power law form for the field line distribution, ρm = ρm,eq(LRE/R)α, where ρm,eq is the value of the mass density ρm at the magnetic equator, L is the L shell, RE is the Earth's radius, R is the geocentric distance to a point on the field line, and α is the power law coefficient. Positive values of α indicate that ρm increases away from the magnetic equator, zero value indicates that ρm is constant along the magnetic field line, and negative α indicates that there is a local peak in ρm at the magnetic equator. Using 12 years of observations of toroidal Alfvén frequencies by the Geostationary Operational Environmental Satellites, we study the typical dependence of inferred values of α on the magnetic local time (MLT), the phase of the solar cycle as specified by the F10.7 extreme ultraviolet solar flux, and geomagnetic activity as specified by the auroral electrojet (AE) index. Over the mostly dayside range of the observations, we find that α decreases with respect to increasing MLT and F10.7, but increases with respect to increasing AE. We develop a formula that depends on all three parameters, , that models the binned values of α within a standard deviation of 0.3. While we do not yet have a complete theoretical understanding of why α should depend on these parameters in such a way, we do make some observations and speculations about the causes. At least part of the dependence is related to that of ρm,eq; higher α, corresponding to steeper variation with respect to magnetic latitude, occurs when ρm,eq is lower.
Self‐similar rupture implied by scaling properties of volcanic earthquakes occurring during the 2004‐2008 eruption of Mount St. Helens, Washington
Authors: Harrington Rebecca M. , Kwiatek Grzegorz , Moran Seth C.
Published: May 2015

We analyze a group of 6073 low‐frequency earthquakes recorded during a week‐long temporary deployment of broadband seismometers at distances of less than 3 km from the crater at Mount St. Helens in September of 2006. We estimate the seismic moment (M0) and spectral corner frequency (f0) using a spectral ratio approach for events with a high signal‐to‐noise (SNR) ratio that have a cross‐correlation coefficient of 0.8 or greater with at least five other events. A cluster analysis of cross‐correlation values indicates that the group of 421 events meeting the SNR and cross‐correlation criteria forms eight event families that exhibit largely self‐similar scaling. We estimate the M0 and f0 values of the 421 events and calculate their static stress drop and scaled energy (ER/M0) values. The estimated values suggest self‐similar scaling within families, as well as between five of eight families (i.e.,
and
constant). We speculate that differences in scaled energy values for the two families with variable scaling may result from a lack of resolution in the velocity model. The observation of self‐similar scaling is the first of its kind for such a large group of low‐frequency volcanic tectonic events occurring during a single active dome extrusion eruption.
Optimizing hydrological consistency by incorporating hydrological signatures into model calibration objectives
Authors: Shafii Mahyar , Tolson Bryan A.
Published: May 2015

The simulated outcome of a calibrated hydrologic model should be hydrologically consistent with the measured response data. Hydrologic modelers typically calibrate models to optimize residual‐based goodness‐of‐fit measures, e.g., the Nash‐Sutcliffe efficiency measure, and then evaluate the obtained results with respect to hydrological signatures, e.g., the flow duration curve indices. The literature indicates that the consideration of a large number of hydrologic signatures has not been addressed in a full multiobjective optimization context. This research develops a model calibration methodology to achieve hydrological consistency using goodness‐of‐fit measures, many hydrological signatures, as well as a level of acceptability for each signature. The proposed framework relies on a scoring method that transforms any hydrological signature to a calibration objective. These scores are used to develop the hydrological consistency metric, which is maximized to obtain hydrologically consistent parameter sets during calibration. This consistency metric is implemented in different signature‐based calibration formulations that adapt the sampling according to hydrologic signature values. These formulations are compared with the traditional formulations found in the literature for seven case studies. The results reveal that Pareto dominance‐based multiobjective optimization yields the highest level of consistency among all formulations. Furthermore, it is found that the choice of optimization algorithms does not affect the findings of this research.
Water input and water release from the subducting Nazca Plate along southern Central Chile (33°S–46°S)
Authors: Völker David , Stipp Michael
Published: May 2015

The age of the subducting Nazca Plate off Chile increases northward from 0 Ma at the Chile Triple Junction (46°S) to 37 Ma at the latitude of Valparaíso (32°S). Age‐related variations in the thermal state of the subducting plate impact on (a) the water influx to the subduction zone, as well as on (b) the volumes of water that are released under the continental fore arc or, alternatively, carried beyond the arc. Southern Central Chile is an ideal setting to study this effect, because other factors for the subduction zone water budget appear constant. We determine the water influx by calculating the crustal water uptake and by modeling the upper mantle serpentinization at the outer rise of the Chile Trench. The water release under fore arc and arc is determined by coupling FEM thermal models of the subducting plate with stability fields of water‐releasing mineral reactions for upper and lower crust and hydrated mantle. Results show that both the influx of water stored in, and the outflux of water released from upper crust, lower crust, and mantle vary drastically over segment boundaries. In particular, the oldest and coldest segments carry roughly twice as much water into the subduction zone as the youngest and hottest segments, but their release flux to the fore arc is only about one fourth of the latter. This high variability over a subduction zone of <1500 km length shows that it is insufficient to consider subduction zones as uniform entities in global estimates of subduction zone fluxes.
A new perspective on environmental controls of marine nitrogen fixation
Authors: Landolfi A. , Koeve W. , Dietze H. , Kähler P. , Oschlies A.
Published: May 2015

Growing slowly, marine N2 fixers are generally expected to be competitive only where nitrogen (N) supply is low relative to that of phosphorus (P) with respect to the cellular N:P ratio (R) of nonfixing phytoplankton. This is at odds with observed high N2 fixation rates in the oligotrophic North Atlantic where the ratio of nutrients supplied to the surface is elevated in N relative to the average R (16:1). In this study, we investigate several mechanisms to solve this puzzle: iron limitation, phosphorus enhancement by preferential remineralization or stoichiometric diversity of phytoplankton, and dissolved organic phosphorus (DOP) utilization. Combining resource competition theory and a global coupled ecosystem‐circulation model, we find that the additional N and energy investments required for exoenzymatic breakdown of DOP give N2 fixers a competitive advantage in oligotrophic P‐starved regions. Accounting for this mechanism expands the ecological niche of N2 fixers also to regions where the nutrient supply is high in N relative to R, yielding, in our model, a pattern consistent with the observed high N2 fixation rates in the oligotrophic North Atlantic.
Impact angle control of interplanetary shock geoeffectiveness: A statistical study
Authors: Oliveira Denny M. , Raeder Joachim
Published: May 2015

We present a survey of interplanetary (IP) shocks using Wind and ACE satellite data from January 1995 to December 2013 to study how IP shock geoeffectiveness is controlled by IP shock impact angles. A shock list covering one and a half solar cycle is compiled. The yearly number of IP shocks is found to correlate well with the monthly sunspot number. We use data from SuperMAG, a large chain with more than 300 geomagnetic stations, to study geoeffectiveness triggered by IP shocks. The SuperMAG SML index, an enhanced version of the familiar AL index, is used in our statistical analysis. The jumps of the SML index triggered by IP shock impacts on the Earth's magnetosphere are investigated in terms of IP shock orientation and speed. We find that, in general, strong (high speed) and almost frontal (small impact angle) shocks are more geoeffective than inclined shocks with low speed. The strongest correlation (correlation coefficient R = 0.78) occurs for fixed IP shock speed and for varied IP shock impact angle. We attribute this result, predicted previously with simulations, to the fact that frontal shocks compress the magnetosphere symmetrically from all sides, which is a favorable condition for the release of magnetic energy stored in the magnetotail, which in turn can produce moderate to strong auroral substorms, which are then observed by ground‐based magnetometers.
Predictive actuator fault‐tolerant control under ellipsoidal bounding
Authors: Witczak Marcin , Buciakowski Mariusz , Aubrun Christophe
Published: May 2015

The paper is devoted to the issue of a robust predictive fault‐tolerant control for linear discrete‐time systems with an application of an ellipsoidal inner bounding of a robust invariant set. The crucial issue is to maintain the state of the system inside the robust invariant feasible set, which is a set of states guaranteeing the stability of the proposed control strategy. The approach begins with fault estimation, and then the fault is compensated along with a robust controller. In a case when robust fault compensation does not provide expected results, which means that the current state does not belong to the robust invariant set, then a suitable predictive control action is performed in order to enhance the ellipsoidal invariant set. This appealing phenomenon makes it possible to enlarge the domain of attraction of the possibly faulty system that makes the proposed approach an efficient solution to the fault‐tolerant control problem. The final part of the paper shows an illustrative example regarding a two‐tank system. Copyright © 2015 John Wiley & Sons, Ltd.
From Bonding Asymmetry to Anharmonic Rattling in Cu12Sb4S13Tetrahedrites: When Lone‐Pair Electrons Are Not So Lonely
Authors: Lai Wei , Wang Yuxing , Morelli Donald T. , Lu Xu
Published: May 2015

Some of the best thermoelectrics are complex materials with rattling guests inside oversized atomic cages. Understanding the chemical and structural origins of the rattling behavior is essential to the design of thermoelectric materials. In this work, a clear connection is established between the local bonding asymmetry and anharmonic rattling modes in tetrahedrite thermoelectrics, enabled by the chemically active electron lone pairs. The studies reveal a five‐atom atomic cage Sb[CuS3]Sb in Cu12Sb4S13tetrahedrites that exhibits strong local bonding asymmetry: covalent bonding inside the CuS3trigonal plane and weak out‐of‐plane bonding induced by the lone‐pair electrons of Sb. This bonding asymmetry leads to out‐of‐plane rattling modes that are quasilocalized and anharmonic with low frequency and large amplitude, and are likely the origin of low thermal conductivity in tetrahedrites. Such knowledge highlights the importance of local structure asymmetry and lone‐pair atoms in driving anharmonic rattling, providing a stepping stone to the discovery and design of next‐generation thermoelectrics.
Thickness Dependence of the Mechanical Properties of Free‐Standing Graphene Oxide Papers
Authors: Gong Tao , Lam Do Van , Liu Renlong , Won Sejeong , Hwangbo Yun , Kwon Sanghyuk , Kim Jinseon , Sun Ke , Kim Jae‐Hyun , Lee Seung‐Mo , Lee Changgu
Published: May 2015

Graphene oxide (GO) papers are candidates for structural materials in modern technology due to their high specific strength and stiffness. The relationship between their mechanical properties and structure needs to be systematically investigated before they can be applied to the broad range fields where they have potential. Herein, the mechanical properties of GO papers with various thicknesses (0.5–100 μm) are investigated using bulge and tensile test methods; this includes the Young's modulus, fracture strength, fracture strain, and toughness. The Young's modulus, fracture strength, and toughness are found to decrease with increasing thickness, with the first two exhibiting differences by a factor of four. In contrast, the fracture strain slightly increases with thickness. Transmission electron, scanning electron, and atomic force microscopy indicate that the mechanical properties vary with thickness due to variations in the inner structure and surface morphology, such as crack formation and surface roughness. Thicker GO papers are weaker because they contain more voids that are produced during the fabrication process. Surface wrinkles and residual stress are found to result in increased fracture strain. Determination of this structure–property relationship provide improved guidelines for the use of GO‐based thin‐film materials in mechanical structures.
Hybrid Improper Ferroelectricity in Multiferroic Superlattices: Finite‐Temperature Properties and Electric‐Field‐Driven Switching of Polarization and Magnetization
Authors: Xu Bin , Wang Dawei , Zhao Hong Jian , Íñiguez Jorge , Chen Xiang Ming , Bellaiche Laurent
Published: May 2015

The so‐called hybrid improper ferroelectricity (HIF) mechanism allows to create an electrical polarization by assembling two nonpolar materials within a superlattice. It may also lead to the control of the magnetization by an electric field when these two nonpolar materials are magnetic in nature, which is promising for the design of novel magneto‐electric devices. However, several issues of fundamental and technological importance are presently unknown in these hybrid improper ferroelectrics. Examples include the behaviors of its polarization and dielectric response with temperature, and the paths to switch both the polarization and magnetization under electric fields. Here, an effective Hamiltonian scheme is used to study the multiferroic properties of the model superlattice (BiFeO3)1/(NdFeO3)1. Along with the development of a novel Landau‐type potential, this approach allows to answer and understand all the aforementioned issues at both microscopic and macroscopic levels. In particular, the polarization and dielectric response are both found to adopt temperature dependences, close to the phase transition, that agree with the behavior expected for first‐order improper ferroelectrics. And most importantly, a five‐state path resulting in the switching of polarization and magnetization under an electric field, via the reversal of antiphase octahedral tiltings, is also identified.
Liquid‐Metal Electrode for High‐Performance Triboelectric Nanogenerator at an Instantaneous Energy Conversion Efficiency of 70.6%
Authors: Tang Wei , Jiang Tao , Fan Feng Ru , Yu Ai Fang , Zhang Chi , Cao Xia , Wang Zhong Lin
Published: May 2015

Harvesting ambient mechanical energy is a key technology for realizing self‐powered electronics, which has tremendous applications in wireless sensing networks, implantable devices, portable electronics, etc. The currently reported triboelectric nanogenerator (TENG) mainly uses solid materials, so that the contact between the two layers cannot be 100% with considering the roughness of the surfaces, which greatly reduces the total charge density that can be transferred and thus the total energy conversion efficiency. In this work, a liquid‐metal‐based triboelectric nanogenerator (LM‐TENG) is developed for high power generation through conversion of mechanical energy, which allows a total contact between the metal and the dielectric. Due to that the liquid–solid contact induces large contacting surface and its shape adaptive with the polymer thin films, the LM‐TENG exhibits a high output charge density of 430 μC m−2, which is four to five times of that using a solid thin film electrode. And its power density reaches 6.7 W m−2 and 133 kW m−3. More importantly, the instantaneous energy conversion efficiency is demonstrated to be as high as 70.6%. This provides a new approach for improving the performance of the TENG for special applications. Furthermore, the liquid easily fluctuates, which makes the LM‐TENG inherently suitable for vibration energy harvesting.
In Vitro and In Vivo Evaluation of Whitlockite Biocompatibility: Comparative Study with Hydroxyapatite and β‐Tricalcium Phosphate
Authors: Jang Hae Lin , Zheng Guang Bin , Park Jungha , Kim Hwan D. , Baek Hae‐Ri , Lee Hye Kyoung , Lee Keunho , Han Heung Nam , Lee Choon‐Ki , Hwang Nathaniel S. , Lee Jae Hyup , Nam Ki Tae
Published: May 2015

Biomimicking ceramics have been developed to induce efficient recovery of damaged hard tissues. Among them, calcium phosphate‐based bioceramics have been the most widely used because of their similar composition with human hard tissue and excellent biocompatibilities. However, the incomplete understanding of entire inorganic phases in natural bone has limited the recreation of complete bone compositions. In this work, broad biomedical evaluation of whitlockite (WH: Ca18Mg2(HPO4)2(PO4)12), which is the secondary inorganic phase in bone, is conducted to better understand human hard tissue and to seek potential application as a biomaterial. Based on the recently developed gram‐scale method for synthesizing WH nanoparticles, the properties of WH as a material for cellular scaffolding and bone implants are assessed and compared to those of hydroxyapatite (HAP: Ca10(PO4)6(OH)2) and β‐tricalcium phosphate (β‐TCP: β‐Ca3(PO4)2). WH‐reinforced composite scaffolds facilitate bone‐specific differentiation compared to HAP‐reinforced composite scaffolds. Additionally, WH implants induce similar or better bone regeneration in calvarial defects in a rat model compared to HAP and β‐TCP implants, with intermediate resorbability. New findings of the properties of WH that distinguish it from HAP and β‐TCP are significant in understanding human hard tissue, mimicking bone tissue at the nanoscale and designing functional bioceramics.
Hydrogel Encapsulation of Cells in Core–Shell Microcapsules for Cell Delivery
Authors: Nguyen Duy Khiem , Son Young Min , Lee Nae‐Eung
Published: May 2015

A newly designed 3D core–shell microcapsule structure composed of a cell‐containing liquid core and an alginate hydrogel shell is fabricated using a coaxial dual‐nozzle electrospinning system. Spherical alginate microcapsules are successfully generated with a core–shell structure and less than 300 μm in average diameter using this system. The thickness of the core and shell can be easily controlled by manipulating the core and shell flow rates. Cells encapsulated in core–shell microcapsules demonstrate better cell encapsulation and immune protection than those encapsulated in microbeads. The observation of a high percentage of live cells (≈80%) after encapsulation demonstrates that the voltage applied for generation of microcapsules does not significantly affect the viability of encapsulated cells. The viability of encapsulated cells does not change even after 3 d in culture, which suggests that the core–shell structure with culture medium in the core can maintain high cell survival by providing nutrients and oxygen to all cells. This newly designed core–shell structure can be extended to use in multifunctional platforms not only for delivery of cells but also for factor delivery, imaging, or diagnosis by loading other components in the core or shell.
Synthesis of Derivatized Chitooligomers using Transglycosidases Engineered from the Fungal GH20 β‐N‐Acetylhexosaminidase
Authors: Slámová Kristýna , Krejzová Jana , Marhol Petr , Kalachova Lubica , Kulik Natallia , Pelantová Helena , Cvačka Josef , Křen Vladimír
Published: May 2015

The synthesis of oligosaccharides using mutant glycosidases has been dynamically developing due to the need for novel carbohydrate‐based materials. Chitooligomers (β‐1→4‐linked oligomers of N‐acetylglucosamine) are bioactive compounds applicable in many industrial and pharmacological areas; however, their accessibility is still rather low. In this work, GH20 β‐N‐acetylhexosaminidase from the fungus Talaromyces flavus was engineered by site‐directed mutagenesis to obtain three efficiently transglycosylating variants with ca. 200‐times suppressed hydrolytic activity. Thus, we have prepared the first GH20 transglycosidases. In the reactions catalyzed by these mutant β‐N‐acetylhexosaminidases we were able to easily prepare and isolate both natural and modified chitooligomers in sufficient amounts for their complete spectral characterization and possible further application. The presented method for the synthesis of chitooligomers with aglycones suitable for linking to other biological structures is simple and robust enough to be easily scaled up.

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Efficient Synthesis of Chiral Indolines using an Imine Reductase from Paenibacillus lactis
Authors: Li Hao , Luan Zheng‐Jiao , Zheng Gao‐Wei , Xu Jian‐He
Published: May 2015

An enzymatic process for the efficient asymmetric reduction of 3H‐indoles as well as 3H‐indole iodides was developed for the first time. Using a new imine reductase identified from Paenibacillus lactis (PlSIR), various chiral indolines were facilely synthesized in good yields and excellent enantiopurities (up to >99% ee) under mild reaction conditions.

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Engineering a Thermostable Transketolase for Unnatural Conversion of (2S)‐Hydroxyaldehydes
Authors: Abdoul Zabar Juliane , Lorillière Marion , Yi Dong , Saravanan Thangavelu , Devamani Titu , Nauton Lionel , Charmantray Franck , Hélaine Virgil , Fessner Wolf‐Dieter , Hecquet Laurence
Published: May 2015

Transketolase (TK) from various origins (including Escherichia coli and yeast) has been described to be fully enantiomer specific for (2R)‐hydroxyaldehyde substrates. A thermostable TK from Geobacillus stearothermophilus (TKgst) was found to display a minor reactivity for (2S)‐hydroxylated aldehydes. To improve this activity by directed protein evolution, we have built a library of TKgst variants by site saturation mutagenesis on two key positions L382 and D470. The best TKgst double mutant L382D/D470S shows up to 4‐ and 5‐fold higher activities towards L‐lactaldehyde and L‐glyceraldehyde as acceptor substrates, respectively. Preparative utility of this mutant was demonstrated by the one‐step synthesis of valuable L‐ribulose and its 5‐deoxy analogue with the L‐erythro (3S,4S) configuration, which were previously inaccessible by using common TK sources.

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Exploiting Enzymatic Dynamic Reductive Kinetic Resolution (DYRKR) in Stereocontrolled Synthesis
Authors: Applegate Gregory A. , Berkowitz David B.
Published: May 2015

Over the past two decades, the domains of both frontline synthetic organic chemistry and process chemistry have seen an increase in crosstalk between asymmetric organic/organometallic approaches and enzymatic approaches to stereocontrolled synthesis. This review highlights the particularly auspicious role for dehydrogenase enzymes in this endeavor, with a focus on dynamic reductive kinetic resolutions (DYRKR) to “deracemize” building blocks, often setting two stereocenters in so doing. The scope and limitations of such dehydrogenase‐mediated processes are overviewed, as are future possibilities for the evolution of enzymatic DYRKR.

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