bluuebunny/crossref_metadata_2025 huggingface dataset:
Automatic Wheelchair for Dog with Two Disabled Hind Legs
Authors: Chansangsri Nuttachart , Thawesaengskulthai Natcha
Published: July 2015

Currently, the wheelchair for disabled dog does not provide the best performance and for therapy dog effectively. The purpose is to clarify the key components which allow the develop an innovation product for dogs with two disables hind legs, especially dogs in Thailand, which can be domestically produced domestically and can meet the needs of users at an appropriate to the physical dog. This study contributes to the disability dogs for physical therapy and healing the pain literature by extending existing theory on new product development. Research methodology is divided into 3 steps: literature review, framework building and action research. The finding is important for management of organization strategies regarding the innovation development product for relevant industries.
Effect of Ball Milling and Crystallizing on Magnetic Properties of Nanocomposite Nd2Fe14B/α-Fe Permanent Magnetic Material
Authors: Jin Yong Ping , Guo Bin
Published: July 2015

Nanocomposite Nd2Fe14B/α-Fe magnetic material had been prepared by ball milling Nd8Fe86B6 as-cast alloy in Argon and subsequent crystallizing. Influence of ball milling on their magnetic properties had been investigated by means of X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Vibrating Sample Magnetometer (VSM) etc. The results show that Nd2Fe14B grain are refined quickly and grain size of α-Fe decreases while extending milling time. After milling for 25h, grain size of α-Fe reaches about 7nm. Magnetic properties increase with milling time. Milled for 25h and crystallizing at 700°C for 30 minutes, samples have the best comprehensive magnetic properties (remanence, coercivity and magnetic energy product). To obtain nanocomposite permanent materials with high magnetic properties, it is necessary to combine ball milling with crystallizing.
Evaluation of Camouflage
Authors: Abele Iveta , Sitvjenkins Igors , Ziemele Inese , Pazane Inese , Vilumsone Ausma
Published: July 2015

Function of military uniform camouflage is to visually hide human outline and minimize the contrast between him and the environment. Every national armed forces develops its own camouflage pattern and color palette. Latvian National Armed Forces are developing universal camouflage pattern to be used in operations in diverse geographic locations.The research objective is to verify conformity of experimental uniform camouflage of green color and evaluate fitting of the camouflage pattern into a particular environment.
Piezoresistivity and Electrical Resistance Relaxation of Polyisoprene Nanostructured Carbon Allotrope Hybrid Composites
Authors: Linarts Artis , Knite Maris
Published: July 2015

Polymer conductive filler composites are believed to be promising materials for flexible force sensor manufacture. Polyisoprene various carbon allotrope hybrid composites were made and their piezoresistive properties depending on the two type’s filler concentration and their ratio have been determined. Electrical resistance relaxations of hybrid composites at constant pressure in room temperature were determined as well. Experimental data of resistance relaxation was analyzed and fitted similarly to stress relaxation of polymers at constant pressure.
Kelvin Probe Force Microscope Observation of Donors’ Arrangement in Si Transistor Channel
Authors: Tyszka Krzysztof , Moraru Daniel , Mizuno Takeshi , Jabłoński Ryszard , Tabe Michiharu
Published: July 2015

Further development of dopant-atom-based transistors requires investigation of the effects of discrete dopant distribution on device operation. Hence, it is important to monitor dopants’ arrangement inside transistor channels. We used Kelvin Probe Force Microscope (KPFM) to measure surface potential profiles of field-effect transistor (FET) channels doped with different concentrations of phosphorus atoms. We observed three basic configurations of dopants: solitary donors, “clusters” of a few coupled donors, and “clusters” of many donors. Our systematic observation provides information about the formation of quantum dots consisting of a single donor or a number of coupled donors.
Dye-Sensitized Solar Cells Based on ZnO Nanorods Array
Authors: Winantyo Rangga , Hartanto Djoko , Murakami Kenji
Published: July 2015

Kim et al. suggest that replacing ZnO particle with ZnO vertically aligned nanorods shows much higher energy conversion efficiency [1]. The difference between nanoparticles and nanorods can be seen on figure 1. Yet, vertically aligned nanorods can be grown through the difficult and expensive methods. Pomar et al. reported the growing through atomic layer deposition (ALD) method [2]. Jeong et al. grew the vertically aligned nanorods using metal-organic chemical vapor deposition (MOCVD) method with really high temperature (700-900oC) [3]. When the nanorods are applied for DSSCs, synthesizing really fine nanorods is not necessary. Lee et al. managed to grow nanorods on the seed layer for DSSC application which was post-annealed at 500-600oC [4]. Hu et al. reported vertically aligned nanorods using low temperature chemical bath method, but the deposition time is between 3 hours and 6 days [5].
Characteristics of Composite Produced with Different Fractions of Wood Waste and High Density Polyethylene (HDPE)
Authors: Terence Mauro Cesar , Melo Jessyka Meierjürgen
Published: July 2015

This paper aims to highlight the study of polymeric composite responsible development with the environment and with the growth of the recycling of materials, from the use of high density polyethylene (HDPE) with eucalyptus wood dust from the furniture manufacturing. The study started from a literature search where they were analyzed the factors involving the subject in question, highlighting the concept of polymer, synthetic fibers, wood powder presence, composites to identify and understand the problem in issue. The study was developed from mechanical, morphological and rheological testing of composites with concentrations of 0, 5, 10 and 20% wood in relation to the polymer matrix in order to characterize and compare the obtained materials. Based on this context, this study was developed based on material supplied by a sawmill, where we used wood dust to perform the necessary tests and experiments, thus aiming to analyze the possibility front the production of HDPE composite from the use of different fractions.
Implementation and Monitoring of Higroregulated Wall Base Ventilation Systems to Control Rising Damp
Authors: Guimarães A.S. , Delgado J.M.P.Q. , de Freitas V.P.
Published: July 2015

This work describes the implementation of two higroregulated wall base ventilation systems in a church in the North of Portugal for the treatment of rising damp and presents the results of four years of the systems monitoring. It is a work developed by LFC – Laboratory of Building Physics of FEUP, where the main goal is to validate and optimize this treatment technique. It was assessed the functioning and effectiveness of the implemented systems, minimizing the likelihood of condensation inside them and maximizing the drying process through the adoption of higroregulated systems. With the monitoring carried out it is possible to conclude that, for the analyzed climate, it is better to adopt a seasonal operation, where the air is admitted from the exterior, during the warm months, and in the cold months the air is admitted from the interior of the Church.
Drying of Rough Rice in Oven: An Experimental Study
Authors: Silva J.V. , Pereira E.M.A. , Andrade T.H.F. , de Lima Antônio Gilson Barbosa
Published: July 2015

This paper aims to present an experimental study of rough rice (BRSMG CONAI cultivar) drying by using a stationary method. The grain was dried in an oven with air mechanical movement under controlled conditions of velocity, temperature and relative humidity. In order to obtain balanced moisture content, the samples studied were kept at 40 and 70°C. Results of the drying and heating kinetics of the grain during the process are shown and analyzed. It was found that higher drying rate and lower time for drying as higher air temperature (70°C) is used. It can be concluded that the reduction of the moisture content of the grain, is considered very complex and, depending on the method and drying conditions, can substantially provokes breaking and cracks, which reduces final product quality.
Mathematical Description of the Trajectory of Vessel Motion in Order to Determine Emission of Harmful Compounds in Exhaust Gases
Authors: Kniaziewicz Tomasz , Załęska-Fornal Agata
Published: July 2015

The growing pressure from the society meant that pollution of the atmosphere by gases of marine engines has become one of the main problems in the protection of the marine environment recent years. Areas of ports like port city or coastal areas are exposed to the impact of pollution from the mainland as well as the considerable impact of harmful compounds contained in the exhaust gas of vessels. In order to determine the share of floating in air pollution and the prevention of the harmful effects of toxic compounds in the exhaust, it is necessary to value the knowledge of marine engines emissions of these compounds from the individual units. This is possible with knowledge of motion parameters of individuals, including their trajectory of motion, the concentrations of individual compounds for these parameters and atmospheric conditions in the region of their presence.The mathematical description of the trajectory of motion of the craft after any track (curve) as a first and essential step in modeling the total emissions of pollutants from internal combustion engines to marine main propulsion of vessels used in the balancing of the pollution is presented in this work.
Exploitation Load Impact on Electrochemical Properties of Shipbuilding 7xxx Series Aluminum Alloy Joints Prepared with TIG and FSW Methods
Authors: Jurczak Wojciech
Published: July 2015

The paper presents the results of investigations on mechanical properties and electrochemical potential distribution within arc welded (TIG) and friction stir welded (FSW) joints subjected to slow strain rate tests. The materials investigated were high-strength 7xxx series (7020 and its modification 7020M) aluminum alloys intended for shipbuilding. The objectives were joint quality assessment and comparison of the advantages of new FSW method with the traditional TIG methods commonly utilized in shipbuilding industry. Joint quality was evaluated based on mechanical investigations, hardness distribution tests and simultaneous electrochemical corrosion potential measurements at various locations within the welded joints.Initiation of corrosion processes on TIG and FSW joints was identified as a radical decrease in corrosion potential related to load followed by oxide layer cracking. Arc welded (TIG) joints of 7xxx series alloys undergo corrosion at lower values of tensile load applied as compared to the FSW joints. Superior mechanical properties and higher corrosion resistance of the FSW joints make this technology well-suited for joining high-strength 7xxx series alloys.
Stratigraphy and sedimentation of the Otto Fiord Formation - a major Mississippian-Pennsylvanian evaporite of subaqueous origin in the Canadian Arctic Archipelago
Authors: Nassichuk W W , Davies G R
Published: July 2015

The Otto Fiord Formation, composed of anhydrite, limestone, shale and sandstone of Late Mississippian to Middle Pennsylvanian age, occurs widely in the interior of the Sverdrup Basin, where its distribution appears to have been influenced by previous or
contemporaneous tectonic events. It is overlain by Middle Pennsylvanian to Lower Permian limestone, siltstone and shale of the Hare Fiord Formation, and the two formations combined define the Basinal Clastic and Evaporitic Belt. The Otto Fiord Formation attains a thickness of 420 m in northern
Ellesmere Island but is considerably thinner in eastern Axel Heiberg Island. In both of these areas it is exposed in normal stratigraphic successions. Elsewhere in Axel Heiberg Island, and in Ellef Ringnes, Amund Ringnes and Melville islands, it outcrops only where it is exposed in more than 100
evaporitic diapirs. The diapirs have been known for more than two decades but the presence of an active halite core beneath a bedded sulphate cap has been known only since 1972 when an exploratory well, Hoodoo L-41, was drilled southeast of Hoodoo Dome proper on Elief Ringnes Island. In this report
stratigraphic relationships and depositional environments of the Otto Fiord are described, and interpretations of the early paleogeography and tectonosedimentary history of the Sverdrup Basin are presented. The Otto Fiord probably was deposited in a subaqueous, hypersaline marine environment. This
interpretation comes at a time when the field of evaporite sedimentology is dominated by examples of alleged paleo-sabkhas. In northern Ellesmere Island the Otto Fiord Formation is abundantly fossiliferous and on the basis of data from ammonoids and foraminifers, including fusulinaceans, rather
refined biostratigraphic correlations have been made between circum-Arctic regions and standard Carboniferous successions in Europe and midcontinental North America. Rather marked diachroneities at the top of the Otto Fiord Formation, over relatively short distances in the Hare Fiord area of
northern Ellesmere Island, coincide with the development of extensive carbonate mounds at the base of the Hare Fiord Formation. Evaporite deposition may have continued behind structural or carbonate barriers in some areas after normal marine conditions became established in
others.
Trilobites from the Long Point Group (Ordovician), Port Au Port Peninsula, southwestern Newfoundland
Authors: Dean W T
Published: July 2015

Trilobite faunules from informal members II and III of the Lourdes Limestone, the lower of two formations constituting the Long Point Group, are of essentially similar taxonomic composition and correspond to a platform fauna as interpreted by H.B. Whittington and
C.P. Hughes (Ordovician geography and fauna! provinces deduced from trilobite distribution; Phil. Trans. Roy. Soc. London, B., v. 263, pp. 235-278, 1972). They include Scotoharpes, Dolichoharpes, Ceraurus, Ceraurinella?, Sphaerexochus, Sphaerocoryphe, Encrinurus, Cybeloides (Cybeloides),
Calyptaulax, Remop/eurides, lsotelus, Anataphrus, 11/aenus, and Thaleops. The following new species are described: Scotoharpes /iliarum, Ceraurus cetus, Encrinurus gibber, Anataphrus glomeratus, and 11/aenus kayi. Most of the generic affinities lie with faunas of Blackriveran or Porterfield age on
the North American craton or in the Appalachian region. The lower part of the succeeding Winterhouse Formation has yielded only Flexicalymene verecunda sp. nov., which suggests a Barneveldian or late Wilderness age. Specifically undetermined Calyptaulax and lsotelus, from the highest part of the
same formation, give no conclusive evidence of age other than Middle or Upper Ordovician, but they are distinct from species in the Lourdes Limestone.
Biochar's effect on soil nitrous oxide emissions from a maize field with lime-adjusted pH treatment
Authors: Hüppi R. , Felber R. , Neftel A. , Six J. , Leifeld J.
Published: July 2015

Abstract. Biochar, a carbon-rich, porous pyrolysis product of organic residues may positively affect plant yield and can, owing to its inherent stability, promote soil carbon sequestration when amended to agricultural soils. Another possible effect of biochar is the reduction in emissions of nitrous oxide (N2O). A number of laboratory incubations have shown significantly reduced N2O emissions from soil when mixed with biochar. Emission measurements under field conditions however are more scarce and show weaker or no reductions, or even increases in N2O emissions. One of the hypothesized mechanisms for reduced N2O emissions from soil is owing to the increase in soil pH following the application of alkaline biochar. To test the effect of biochar on N2O emissions in a temperate maize system, we set up a field trial with a 20 t ha−1 biochar treatment, a limestone treatment adjusted to the same pH as the biochar treatment, and a control treatment without any addition. An automated static chamber system measured N2O emissions for each replicate plot (n = 3) every 3.6 h over the course of 8 months. The field was conventionally fertilised at a rate of 160 kg-N ha−1 in 3 applications of 40, 80 and 40 kg-N ha−1. Cumulative N2O emissions were 53 % smaller in the biochar compared to the control treatment. However, the effect of the treatments overall was not statistically significant (p = 0.26) because of the large variability in the dataset. Limed soils emitted similar mean cumulative amounts of N2O as the control. This indicates that the observed N2O reduction effect of biochar was not caused by a pH effect.
Dendrogramas de densidade para Hovenia dulcis Thunberg na região central do estado do Rio Grande do Sul, Brasil
Authors: Selle Gerson Luiz , Fleig Frederico Dimas , Schneider Paulo Renato , Albernard Luiz Antônio Jacques de , Vuaden Elisabete , Braz Evaldo Muñoz
Published: July 2015

O objetivo principal deste trabalho foi elaborar dendrogramas para o manejo de densidade (DMD), em populações de Hovenia dulcis localizadas na região central do estado do Rio Grande do Sul, Brasil. Para tanto, foram utilizadas informações de dois povoamentos, com idades de 25 anos, localizado na Fundação de Pesquisa Agropecuária (FEPAGRO) e de uma população de árvores livres, com DAPs variando de 5 a 45 cm, localizado no campus da Universidade Federal de Santa Maria (UFSM), RS. Nos povoamentos sob concorrência, os dados foram coletados em árvores dos estratos dominante, intermediário e dominado, pelo método da densidade pontual. As árvores livres de concorrência foram coletadas sob a forma de censo. Como conclusão obteve-se que o modelo de Reineke ajustou-se satisfatoriamente para estimar as linhas de densidade de fechamento do dossel e de autodesbaste, com os coeficientes angulares se aproximando de -1,5, comprovando que a lei da potência de -3/2 de autodesbaste foi contemplada e que a hipótese postulada por Reineke tambem foi satisfeita. A densidade populacional, para a lotação do dossel, foi de 42,5% do número máximo de árvores, sendo possível construir diagramas para o manejo da densidade, dos 5 aos 31 cm de diâmetro da árvore de área basal média.
Nutrientes na serapilheira em um fragmento de Floresta Estacional Decidual, Itaara, RS
Authors: Viera Márcio , Caldato Silvana L. , Rosa Suzana Ferreira da , Kanieski Maria Raquel , Araldi Dane Block , Santos Sidinei Rodrigues dos , Schumacher Mauro Valdir
Published: July 2015

O presente estudo teve por objetivo quantificar a massa e o estoque de nutrientes da serapilheira sobre o solo em um fragmento de Floresta Estacional Decidual no município de Itaara, RS. Para a quantificação da serapilheira, a amostragem foi realizada conforme frações estabelecidas em metodologias: uma para folhas e galhos com diâmetro menor a 1 cm (S0) e outra para material lenhoso com diâmetro de 1 cm a 3 cm (S1), 3,1 cm a 6 cm (S2) e maior que 6 cm (S3). Para a avaliação da fração S0, foram coletadas aleatoriamente cinquenta amostras com moldura metálica de 25 cm x 25 cm, já para a avaliação das frações S1, S2 e S3, foram distribuídas aleatoriamente dez parcelas de 3 m x 2 m na área de estudo. O material amostrado foi acondicionado e levado ao Laboratório de Ecologia Florestal da Universidade Federal de Santa Maria onde foram secas, pesadas, moídas e analisadas quanto aos teores de macro e micronutrientes. Cerca de 45% da serapilheira depositada sobre o solo é formada por materiais lenhosos senescentes (galhos e troncos). As frações da serapilheira diferiram significativamente (p < 0,05), quanto aos teores de nutrientes, com exceção de Mg e Cu; geralmente a fração S0 apresentou teores mais altos de nutrientes. As frações S1, S2 e S3 apresentaram um acúmulo de nutrientes variando de 53,3% para o K a 8,7% para o Fe em relação ao total da serapilheira, demonstrando a importância da quantificação desses componentes durante a avaliação do estoque de nutrientes contidos na serapilheira de ecossistema florestal.
Estimativa da idade de segregação do lenho juvenil a adulto de Carya illinoinensis (Wangenh) K. Koch por meio de parâmetros anatômicos da madeira
Authors: Gatto Darci Alberto , Haselein Clovis Roberto , Buligon Ediane Andréia , Calegari Leandro , Stangerlin Diego Martins , Melo Rafael Rodolfo de , Trevisan Rômulo , Santini Elio José
Published: July 2015

Esse estudo teve como objetivo delimitar a idade de maturação do lenho utilizando-se de características anatômicas da madeira de Carya illinoinensis (Wangenh) K. Koch (nogueira-pecã) por meio da segregação dos lenhos juvenil e adulto. Para a tecnologia da madeira, aliada ao manejo florestal, é imprescindível o conhecimento da delimitação do lenho juvenil e adulto. Os desbastes, na grande maioria dos casos, devem levar em consideração esse parâmetro, já que o lenho juvenil possui características inferiores a do lenho adulto, e diferentes proporções de cada tipo de lenho vão interferir na qualidade e no uso da madeira. Para a realização do presente estudo, foram eleitas três árvores adultas, de fuste reto e cilíndrico, com DAP superior a 30 cm, localizadas na Encosta Superior do Nordeste do estado do Rio Grande do Sul. Foi retirado um disco por árvore, com aproximadamente 2 cm de espessura a 0,10 m de altura do tronco. De cada disco, retirou-se, com auxilio de uma serra-de-fita, uma bagueta central de 2,0 cm de largura, bem orientada no sentido radial, incluindo a medula no centro, dividiu-se então a bagueta em duas amostras "A" e "B". Dessas, sorteou-se uma, e separou-se apenas o lenho inicial de cada anel de crescimento para a maceração (método de Jeffrey) conforme descrito por Burger e Richter (1991). Mediram-se, primeiramente, com auxílio de um microscópio ótico com régua micrométrica, o comprimento, largura e diâmetro do lume individual de cem fibras no primeiro anel de crescimento (próximo à casca), e, posteriormente, definiram-se trinta fibras, por anel de crescimento, como estatisticamente suficiente para o ensaio. A espessura das paredes das fibras foi obtida pela metade da diferença do diâmetro da fibra e do lume. A segregação dos dois tipos de lenho foi definida pela variação radial (medula-casca) das características anatômicas (comprimento, diâmetro, largura do lume e espessura da parede das fibras) por meio de duas regressões lineares simples. Os resultados indicaram que o comprimento de fibra é a melhor característica para a definição do ano de segregação. Utilizando-se essa variável, determinou-se o ano de segregação dos lenhos juvenil-adulto em 16 anos. Por sua vez, os parâmetros anatômicos, diâmetro das fibras, largura do lume e espessura da parede das fibras mostraram-se inadequados, para a estimativa da idade de segregação, em conseqüência dos baixos coeficientes de determinação (R²), altos erros de estimativa (Sxy) e baixos valores para Razão F, observados nos modelos estatísticos.
A review of surrogate models and their application to groundwater modeling
Authors: Asher M. J. , Croke B. F. W. , Jakeman A. J. , Peeters L. J. M.
Published: July 2015

The spatially and temporally variable parameters and inputs to complex groundwater models typically result in long runtimes which hinder comprehensive calibration, sensitivity, and uncertainty analysis. Surrogate modeling aims to provide a simpler, and hence faster, model which emulates the specified output of a more complex model in function of its inputs and parameters. In this review paper, we summarize surrogate modeling techniques in three categories: data‐driven, projection, and hierarchical‐based approaches. Data‐driven surrogates approximate a groundwater model through an empirical model that captures the input‐output mapping of the original model. Projection‐based models reduce the dimensionality of the parameter space by projecting the governing equations onto a basis of orthonormal vectors. In hierarchical or multifidelity methods the surrogate is created by simplifying the representation of the physical system, such as by ignoring certain processes, or reducing the numerical resolution. In discussing the application to groundwater modeling of these methods, we note several imbalances in the existing literature: a large body of work on data‐driven approaches seemingly ignores major drawbacks to the methods; only a fraction of the literature focuses on creating surrogates to reproduce outputs of fully distributed groundwater models, despite these being ubiquitous in practice; and a number of the more advanced surrogate modeling methods are yet to be fully applied in a groundwater modeling context.
Hierarchical Bayesian clustering for nonstationary flood frequency analysis: Application to trends of annual maximum flow in Germany
Authors: Sun Xun , Lall Upmanu , Merz Bruno , Dung Nguyen Viet
Published: July 2015

Especially for extreme precipitation or floods, there is considerable spatial and temporal variability in long term trends or in the response of station time series to large‐scale climate indices. Consequently, identifying trends or sensitivity of these extremes to climate parameters can be marked by high uncertainty. When one develops a nonstationary frequency analysis model, a key step is the identification of potential trends or effects of climate indices on the station series. An automatic clustering procedure that effectively pools stations where there are similar responses is desirable to reduce the estimation variance, thus improving the identification of trends or responses, and accounting for spatial dependence. This paper presents a new hierarchical Bayesian approach for exploring homogeneity of response in large area data sets, through a multicomponent mixture model. The approach allows the reduction of uncertainties through both full pooling and partial pooling of stations across automatically chosen subsets of the data. We apply the model to study the trends in annual maximum daily stream flow at 68 gauges over Germany. The effects of changing the number of clusters and the parameters used for clustering are demonstrated. The results show that there are large, mainly upward trends in the gauges of the River Rhine Basin in Western Germany and along the main stream of the Danube River in the south, while there are also some small upward trends at gauges in Central and Northern Germany.
Influence of Sulfonic Acid Group on Sulfonated Polyethersulfone Membrane for PEM Fuel Cell: A First‐Principles Study
Authors: Kwon Soonchul , Yang Yooseong , Lee Seung Geol
Published: July 2015

The introduction of a protogenic group such as sulfonic acid allows the operation of polymer electrolyte membranes for fuel cells at intermediate temperature (>100 °C) and very low humidity. A sulfonated polyethersulfone (SPES) membrane with additional sulfonation was simulated by density functional theory calculations to determine the beneficial effect of the sulfonic group, which induces hydrophilicity for increased hydrogen conductivity. A higher degree of sulfonation enhances the H2O adsorption. In particular, trans‐di‐SPES (trans‐DSPES), with higher charge transfer to H2O and more hydrogen bonds, is more favorable for H2O adsorption than cis‐DSPES; this is attributed to its narrow band gap (2.84 eV) and high adsorption energy (−0.81 eV) compared to cis‐DSPES (2.96 and −0.69 eV, respectively). Theoretical findings suggest that adding the sulfonic acid group ultimately yields greater H2O adsorption on DSPES, increasing the hydrophilicity.
Factors Controlling β‐Elimination Reactions in Group 10 Metal Complexes
Authors: Sosa Carrizo E. Daiann , Bickelhaupt F. Matthias , Fernández Israel
Published: July 2015

Invited for the cover of this issue are Daiann Sosa Carrizo and Israel Fernández at the Universidad Complutense in Madrid together with Matthias Bickelhaupt at the VU University in Amsterdam. The image depicts a goldfish jumping out of its bowl, comparable to how chlorine atoms can undergo a β‐elimination reaction and migrate from the alkyl ligand to the Group 10 transition metal without a prior ligand dissociation. Read the full text of the article at 10.1002/chem.201502036.
A neutral polydisulfide containing Gd(III) DOTA monoamide as a redox‐sensitive biodegradable macromolecular MRI contrast agent
Authors: Ye Zhen , Zhou Zhuxian , Ayat Nadia , Wu Xueming , Jin Erlei , Shi Xiaoyue , Lu Zheng‐Rong
Published: July 2015

This work aims to develop safe and effective gadolinium (III)‐based biodegradable macromolecular MRI contrast agents for blood pool and cancer imaging. A neutral polydisulfide containing macrocyclic Gd‐DOTA monoamide (GOLS) was synthesized and characterized. In addition to studying the in vitro degradation of GOLS, its kinetic stability was also investigated in an in vivo model. The efficacy of GOLS for contrast‐enhanced MRI was examined with female BALB/c mice bearing 4T1 breast cancer xenografts. The pharmacokinetics, biodistribution, and metabolism of GOLS were also determined in mice. GOLS has an apparent molecular weight of 23.0 kDa with T1 relaxivities of 7.20 mM−1 s−1 per Gd at 1.5 T, and 6.62 mM−1 s−1 at 7.0 T. GOLS had high kinetic inertness against transmetallation with Zn2+ ions, and its polymer backbone was readily cleaved by L‐cysteine. The agent showed improved efficacy for blood pool and tumor MR imaging. The structural effect on biodistribution and in vivo chelation stability was assessed by comparing GOLS with Gd(HP‐DO3A), a negatively charged polydisulfide containing Gd‐DOTA monoamide GODC, and a polydisulfide containing Gd‐DTPA‐bisamide (GDCC). GOLS showed high in vivo chelation stability and minimal tissue deposition of gadolinium. The biodegradable macromolecular contrast agent GOLS is a promising polymeric contrast agent for clinical MR cardiovascular imaging and cancer imaging. Copyright © 2015 John Wiley & Sons, Ltd.
Virtual analysis of structurally diverse synthetic analogs as inhibitors of snake venom secretory phospholipase A2
Authors: Sivaramakrishnan V. , Ilamathi M. , Ghosh K. S. , Sathish S. , Gowda T. V. , Vishwanath B. S. , Rangappa K. S. , Dhananjaya B. L.
Published: July 2015

Due to the toxic pathophysiological role of snake venom phospholipase A2 (PLA2), its compelling limitations to anti‐venom therapy in humans and the need for alternative therapy foster considerable pharmacological interest towards search of PLA2 specific inhibitors. In this study, an integrated approach involving homology modeling, molecular dynamics and molecular docking studies on VRV‐PL‐V (Vipera russellii venom phospholipase A2 fraction—V) belonging to Group II‐B secretory PLA2 from Daboia russelli pulchella is carried out in order to study the structure‐based inhibitor design. The accuracy of the model was validated using multiple computational approaches. The molecular docking study of this protein was undertaken using different classes of experimentally proven, structurally diverse synthetic inhibitors of secretory PLA2 whose selection is based on IC50 value that ranges from 25 μM to 100 μM. Estimation of protein–ligand contacts by docking analysis sheds light on the importance of His 47 and Asp 48 within the VRV‐PL‐V binding pocket as key residue for hydrogen bond interaction with ligands. Our virtual analysis revealed that compounds with different scaffold binds to the same active site region. ADME analysis was also further performed to filter and identify the best potential specific inhibitor against VRV‐PL‐V. Additionally, the e‐pharmacophore was generated for the best potential specific inhibitor against VRV‐PL‐V and reported here. The present study should therefore play a guiding role in the experimental design of VRV‐PL‐V inhibitors that may provide better therapeutic molecular models for PLA2 recognition and anti‐ophidian activity. Copyright © 2015 John Wiley & Sons, Ltd.
Simultaneous Improvement of array factor directivity and side lobe level of time‐modulated linear antenna arrays using opposition‐based harmony search algorithm
Authors: Ram Gopi , Mandal Durbadal , Kar Rajib , Ghoshal Sakti Prasad
Published: July 2015

In this paper, simultaneous improvement of array factor directivity and side lobe level of time‐modulated linear antenna arrays using opposition‐based harmony search algorithm has been dealt with. Because of the periodic function of switching time, the same antenna array will radiate at fundamental (center) frequency as well as its harmonic frequencies. The first two harmonic frequencies are (f0 + Fp) and (f0 + 2Fp), where f0 and Fp are operating frequency and pulse repetition frequency, respectively. Four case studies have been adapted; Case‐1: optimal switching time sequence of each element; Case‐2: optimal switching time sequence of each element and optimal non‐uniform inter‐element spacing; Case‐3: optimal switching time sequence of each element, optimal excitation phase of each element, and optimal uniform inter‐element spacing; Case‐4 refers to optimal switching time sequence of each element and optimal uniform inter‐element spacing. Simulation results reflect that Case‐4 outperforms Case‐1, Case‐2, and Case‐3. The objective function was judiciously chosen in such a way that it can simultaneously improve the array factor directivity as well as side lobe level. Considered for the analysis was 16‐element linear antenna array. Various simulation results are presented showing better side lobe performance, better side band performance, and improved array factor directivity with respect to the uniform array having the same number of elements. The numerical results show the power radiated by any harmonic frequency is less as compared with the power radiated at the center frequency called the fundamental frequency. It has also been observed that as the harmonic frequency increases, sideband level and power radiated by the antenna at its harmonic frequency decrease. Copyright © 2015 John Wiley & Sons, Ltd.
Pupil Response to Threat in Trauma‐Exposed Individuals With or Without PTSD
Authors: Cascardi Michele , Armstrong Davine , Chung Leeyup , Paré Denis
Published: July 2015

An infrequently studied and potentially promising physiological marker for posttraumatic stress disorder (PTSD) is pupil response. This study tested the hypothesis that pupil responses to threat would be significantly larger in trauma‐exposed individuals with PTSD compared to those without PTSD. Eye‐tracking technology was used to evaluate pupil response to threatening and neutral images. Recruited for participation were 40 trauma‐exposed individuals; 40.0% (n = 16) met diagnostic criteria for PTSD. Individuals with PTSD showed significantly more pupil dilation to threat‐relevant stimuli compared to the neutral elements (Cohen's d = 0.76), and to trauma‐exposed controls (Cohen's d = 0.75). Pupil dilation significantly accounted for 12% of variability in PTSD after time elapsed since most recent trauma, cumulative violence exposure, and trait anxiety were statistically adjusted. The final logistic regression model was associated with 85% of variability in PTSD status and correctly classified 93.8% of individuals with PTSD and 95.8% of those without. Pupil reactivity showed promise as a physiological marker for PTSD.
Effect of Electron Beam Radiation on the Mechanical Properties of Low‐Density Polyethylene (LDPE)/Waste Tire Dust (WTD) Blends
Authors: Thevy Ratnam Chantara , Ramarad Suganti , Khalid Mohd , Abdull Rashid Suhaida , Mohamed Zurina
Published: July 2015

Blends of low‐density polyethylene, LDPE /waste tire dust, WTD were prepared by using a Haake mixer at 100/0, 90/10, 80/20, 70/30, and 60/40 blend ratios. The blends were irradiated by using a 3.0 MeV electron beam (EB) machine at 0, 50, 100, 150 and 200 kGy irradiation doses. All the samples were tested for mechanical properties such as tensile strength, elongation at break, modulus at 100% strain, hardness and impact strength before and after irradiation exposure. Prior to irradiation, the mechanical properties of the blends (except for impact strength) found to show a gradual decrease with the addition of WTD. Enhancements in the mechanical properties were achieved upon EB irradiation of the LDPE/WTD blends. This is attributed to the irradiation induced crosslinking of LDPE matrix along with the increase in the compatibility of LDPE/WTD blend through irradiation‐induced co crosslinking between the WTD and LDPE at the interface. The gel fraction results and scanning electron micrographs of the fracture surfaces of the LDPE/WTD blends show evidences consistent with the above contention.
Fast Photoswitching Azo Dyes
Authors: Hegde Gurumurthy , Yuvaraj A. R. , Sinn‐Yam Wan , Yusoff Mashitah M.
Published: July 2015

Fast photoswitching azobenzene molecules were incorporated into isoflavone moieties. These molecules exhibit a liquid crystalline nematic state at certain temperature intervals. UV/Vis spectrophotometry investigations on solutions reveal that E/Z conversion takes place around 1 s, whereas thermal back relaxation, namely Z/E, takes around 6 min. This is the first example of fast photoswitching isoflavones in solution. This study has potential to create optical data storage devices when transferred to solid surfaces.
Convergence of an implicit Voronoi finite volume method for reaction–diffusion problems
Authors: Fiebach André , Glitzky Annegret , Linke Alexander
Published: July 2015

We investigate the convergence of an implicit Voronoi finite volume method for reaction–diffusion problems including nonlinear diffusion in two space dimensions. The model allows to handle heterogeneous materials and uses the chemical activities of the involved species as primary variables. The numerical scheme works with boundary conforming Delaunay meshes and preserves positivity and the dissipative property of the continuous system. Starting from a result on the global stability of the scheme (uniform, mesh‐independent global upper, and lower bounds), we prove strong convergence of the chemical activities and their gradients to a weak solution of the continuous problem. To illustrate the preservation of qualitative properties by the numerical scheme, we present a long‐term simulation of the Michaelis–Menten–Henri system. Especially, we investigate the decay properties of the relative free energy over several magnitudes of time, and obtain experimental orders of convergence for this quantity. © 2015 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 32: 141–174, 2016
A powerful test for Balaam's design
Authors: Mori Joji , Kano Yutaka
Published: July 2015

The crossover trial design (AB/BA design) is often used to compare the effects of two treatments in medical science because it performs within‐subject comparisons, which increase the precision of a treatment effect (i.e., a between‐treatment difference). However, the AB/BA design cannot be applied in the presence of carryover effects and/or treatments‐by‐period interaction. In such cases, Balaam's design is a more suitable choice. Unlike the AB/BA design, Balaam's design inflates the variance of an estimate of the treatment effect, thereby reducing the statistical power of tests. This is a serious drawback of the design. Although the variance of parameter estimators in Balaam's design has been extensively studied, the estimators of the treatment effect to improve the inference have received little attention. If the estimate of the treatment effect is obtained by solving the mixed model equations, the AA and BB sequences are excluded from the estimation process. In this study, we develop a new estimator of the treatment effect and a new test statistic using the estimator. The aim is to improve the statistical inference in Balaam's design. Simulation studies indicate that the type I error of the proposed test is well controlled, and that the test is more powerful and has more suitable characteristics than other existing tests when interactions are substantial. The proposed test is also applied to analyze a real dataset. Copyright © 2015 John Wiley & Sons, Ltd.
Accuracy of transvaginal ultrasound for diagnosis of deep endometriosis in the rectosigmoid: systematic review and meta‐analysis
Authors: Guerriero S. , Ajossa S. , Orozco R. , Perniciano M. , Jurado M. , Melis G. B. , Alcazar J. L.
Published: July 2015

Objectives

To review the diagnostic accuracy of transvaginal ultrasound (TVS) in the preoperative detection of rectosigmoid endometriosis in patients with clinical suspicion of deep infiltrating endometriosis (DIE), comparing enhanced (E‐TVS) and non‐enhanced approaches.

Methods

An extensive search was performed in MEDLINE (PubMed) and EMBASE for studies published between January 1989 and December 2014. The eligibility criterion was use of TVS for preoperative detection of rectosigmoid endometriosis in women with clinical suspicion of DIE, using surgical data as the reference standard. Study quality was assessed using Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) guidelines and the Quality Assessment of Diagnostic Accuracy Studies‐2 (QUADAS‐2) tool.

Results

Our extended search identified a total of 801 citations, among which 19 studies (n = 2639) were considered eligible and included in the meta‐analysis. Overall pooled sensitivity, specificity, positive likelihood ratio (LR+) and negative likelihood ratio (LR–) of TVS for detecting DIE in the rectosigmoid were 91% (95%CI, 85–94%), 97% (95%CI, 95–98%), 33.0 (95%CI, 18.6–58.6) and 0.10 (95%CI, 0.06–0.16), respectively. Significant heterogeneity was found for sensitivity (I2, 90.8%; Cochran Q, 195.2; P < 0.001) and specificity (I2, 76.8%; Cochran Q, 77.7; P < 0.001). We did not find statistical differences between non‐enhanced TVS and E‐TVS (P = 0.304).

Conclusion

Overall diagnostic performance of TVS for DIE of the rectosigmoid is good. However, further studies with improved quality in design are needed. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.
Time-lapse Raman imaging of osteoblast differentiation
Authors: Hashimoto Aya , Yamaguchi Yoshinori , Chiu Liang-da , Morimoto Chiaki , Fujita Katsumasa , Takedachi Masahide , Kawata Satoshi , Murakami Shinya , Tamiya Eiichi
Published: July 2015

Osteoblastic mineralization occurs during the early stages of bone formation. During this mineralization, hydroxyapatite (HA), a major component of bone, is synthesized, generating hard tissue. Many of the mechanisms driving biomineralization remain unclear because the traditional biochemical assays used to investigate them are destructive techniques incompatible with viable cells. To determine the temporal changes in mineralization-related biomolecules at mineralization spots, we performed time-lapse Raman imaging of mouse osteoblasts at a subcellular resolution throughout the mineralization process. Raman imaging enabled us to analyze the dynamics of the related biomolecules at mineralization spots throughout the entire process of mineralization. Here, we stimulated KUSA-A1 cells to differentiate into osteoblasts and conducted time-lapse Raman imaging on them every 4 hours for 24 hours, beginning 5 days after the stimulation. The HA and cytochrome c Raman bands were used as markers for osteoblastic mineralization and apoptosis. From the Raman images successfully acquired throughout the mineralization process, we found that β-carotene acts as a biomarker that indicates the initiation of osteoblastic mineralization. A fluctuation of cytochrome c concentration, which indicates cell apoptosis, was also observed during mineralization. We expect time-lapse Raman imaging to help us to further elucidate osteoblastic mineralization mechanisms that have previously been unobservable.
Detection and quantification of new psychoactive substances (NPSs) within the evolved “legal high” product, NRG-2, using high performance liquid chromatography-amperometric detection (HPLC-AD)
Authors: Zuway Khaled Y. , Smith Jamie P. , Foster Christopher W. , Kapur Nikil , Banks Craig E. , Sutcliffe Oliver B.
Published: July 2015

Demonstrated for the first time, the combination of HPLC with amperometric detection (HPLC-AD) for the qualitative and quantitative analysis of synthetic cathinones 4-MMC and 4-MEC using graphite screen-printed macroelectrodes (GSPEs).
Detection of heparin based on the conformational switch of DNA
Authors: Jiang Hong , Wang Guangfeng , Zhang Xiaojun
Published: July 2015

A simple, fast, sensitive and label-free fluorescent assay for sensing heparin based on the electrostatic attraction between heparin and coralyne is reported.
Bond-shift isomers: the co-existence of allenic and propargylic phenylnitrile imines
Authors: Nunes Cláudio M. , Reva Igor , Fausto Rui , Bégué Didier , Wentrup Curt
Published: July 2015

Two bond-shift isomers of phenylnitrile imine resulting from photochemistry of 5-phenyltetrazole.
Selective gas adsorption in microporous metal–organic frameworks incorporating urotropine basic sites: an experimental and theoretical study
Authors: Sapchenko S. A. , Dybtsev D. N. , Samsonenko D. G. , Belosludov R. V. , Belosludov V. R. , Kawazoe Y. , Schröder M. , Fedin V. P.
Published: July 2015

Urotropine-based porous coordination polymers with free N-donors demonstrate selective adsorption towards acidic gas substrates (C2H2or CO2) as confirmed by isotherm measurements andab initioDFT calculations.
O2 and H2O2 transformation steps for the oxygen reduction reaction catalyzed by graphitic nitrogen-doped carbon nanotubes in acidic electrolyte from first principles calculations
Authors: Li Yuhang , Zhong Guoyu , Yu Hao , Wang Hongjuan , Peng Feng
Published: July 2015

DFT calculations reveal a mixed mechanism for the oxygen reduction reaction catalyzed by nitrogen-doped carbon nanotubes in acidic electrolyte.
Thermodynamic properties of neutral and charged oxygen vacancies in BaZrO3 based on first principles phonon calculations
Authors: Bjørheim Tor S. , Arrigoni Marco , Gryaznov Denis , Kotomin Eugene , Maier Joachim
Published: July 2015

First principles phonon calculations reveal that neutral and charged oxygen vacancies in BaZrO3 display widely different vibrational and thermodynamic properties.
Multiscale modeling of the trihexyltetradecylphosphonium chloride ionic liquid
Authors: Wang Yong-Lei , Sarman Sten , Li Bin , Laaksonen Aatto
Published: July 2015

Hierarchical trihexyltetradecylphosphonium cationic and chloride anionic models.
Quantifying the origin of inter-adsorbate interactions on reactive surfaces for catalyst screening and design
Authors: Krishnamoorthy Aravind , Yildiz Bilge
Published: July 2015

The adsorption of reactant molecules alters the electronic structure of the catalyst. This induces an effective interaction between adsorbate molecules, affecting the adsorption energy of the reactant and the reactivity of the catalyst surface.
Structure–property relationship of donor–acceptor acridones – an optical, electrochemical and computational study
Authors: Thériault K. D. , Radford C. , Parvez M. , Heyne B. , Sutherland T. C.
Published: July 2015

The effect of changing acceptor strength on intramolecular charge transfer absorption and its implication towards organic materials are investigated.
Structural and functional insights into the conductive pili of Geobacter sulfurreducens revealed in molecular dynamics simulations
Authors: Feliciano G. T. , Steidl R. J. , Reguera G.
Published: July 2015

Geobacter sulfurreducens(GS) electronically connects with extracellular electron acceptors using such as Fe(iii) oxides and U(vi) conductive protein filaments or pili.
The effect of impurities in ultra-thin hydrogenated silicene and germanene: a first principles study
Authors: Rupp Caroline J. , Chakraborty Sudip , Ahuja Rajeev , Baierle Rogério J.
Published: July 2015

Spin polarized density functional theory within the GGA–PBE and HSE06 approach for the exchange correlation term has been used to investigate the stability and electronic properties of nitrogen and boron impurities in single layers of silicane and germanane.
Correlation between hierarchical structure of crystal networks and macroscopic performance of mesoscopic soft materials and engineering principles
Authors: Lin Naibo , Liu Xiang Yang
Published: July 2015

The performance of soft materials is correlated with the hierarchical crystal network structure by topology, correlation length, symmetry/ordering, and strength.