bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dielectric and Piezoelectric Properties of Gd-modified (1-x) BiFeO3-xPbTiO3 Ceramics with a Morphotropic Phase Boundary
Authors: Wang Dalei , Bu Shundong , Jin Guoxi , RuiDai  , Jin Dengren , Cheng Jinrong 
Published: April 2013

ABSTRACT(1-x)(Bi0.8Gd0.2)FeO3-xPbTiO3 (BGF-PT) solid solutions ceramics of x=0.55,0.50,0.4975, 0.49 and 0.45 were prepared by the mixed oxide method. Gd3+ of 20 at% was introduced into the Bi3+ site to improve the dielectric and piezoelectric properties of BFPT without causing the significant reduction of Curie temperature (Tc). X-ray diffraction analysis shows a transformation from the tetragonal (T) to rhombohedral (R) phase with the increase of BGF content. The morphotropic phase boundary was determined by measuring the dielectric and piezoelectric properties of BGF-PT within a wide composition range. BGF-PT for x=0.4975 shows the coexistence of T and R phases with the dielectric constant and loss of about 895 and 0.031 respectively at the frequency of 102 Hz.
The Role of Defects in Li3ClO Solid Electrolyte: Calculations and Experiments
Authors: Braga M. Helena , Stockhausen Verena , Oliveira Joana C.E. , Ferreira Jorge A. 
Published: April 2013

ABSTRACTWe have analyzed the hopping movement of a new ionic solid electrolyte by calculating defect formation energies and activation barriers. The role of the lattice during diffusion was established. Thermodynamic properties were determined by means of first principles and phonon calculations at working temperatures. The new solid electrolyte, an antiperovskite, Li3-2xMxAO (in which M is a higher valent cation like Ca2+ or Mg2+ and A is a halide like Cl- or Br- or a mixture of halides), was studied either pure or doped. Moreover, we present experimental ionic conductivity data for these novel solid state ionic conductors for the doped and the pure solid electrolyte from room temperature and up to ∼253 °C. In this paper, we compare the ionic conductivity of the latter solid electrolyte with other fast ionic conductors.
Superhydrophobicity of AA2024 by a simple solution immersion technique
Authors: Lakshmi R. V. , Bharathidasan T. , Basu Bharathibai J. 
Published: April 2013

Superhydrophobic films with hierarchical structures were fabricated on AA2024 alloy by a simple solution immersion technique comprising surface pretreatment by alkaline etching and immersion in an ethanolic solution of long-chain fatty acid. The etched surface was hydrophobically modified using alkanoic acids. The effect of etchant concentration and carbon chain lengths of alkanoic acids on WCA of the alloy surface was studied. Field emission scanning electron microscopy, energy dispersive spectrometer and water contact angle measurements were performed to characterize the morphological features, chemical composition and wettability of the surfaces. The resulting superhydrophobic surfaces exhibited water contact angles of about 157° and sliding angle <2°. Surface modification with fluoroalkylsilane also rendered superhydrophobicity to the etched surfaces. The wettability behavior of the superhydrophobic surface was correlated to surface roughness using Cassie-Baxter model.
Liquid Screen: A Novel Method To Produce an In-Situ Gravel Pack
Authors: Ikem V.O.. O. , Menner A.. , Bismarck A.. , Norman L.R.. R. 
Published: April 2013

Summary
Gravel packs are conventionally used as a permeable solid layer in the annulus between a production screen and the walls of the wellbore in weakly consolidated subterranean formations. Gravel packing is a well-known technique for sand control, whereby unconsolidated fines produced from the soft formation are filtered away from the production fluids. However, gravel packs can be problematic. The bridging of sand particles within the gravel pack can create voids that can result in mechanical failures or significantly reduce the effectiveness of gravel packs to restrain fines from flowing along with the hydrocarbons produced.
As an alternative, we present a pioneering method to prepare void-free and mechanically sound permeable barriers in subterranean formations as an alternative to gravel packing. The method of preparation involves the curing of Pickering water-in-oil medium-internal-phase emulsions (MIPEs) or high-internal-phase emulsions (HIPEs) containing monomers in the annular space between a rock formation and pipe. The emulsions were prepared simply by adding low amounts of nonionic surfactant and dispersant to premade Pickering emulsions that were stabilized by oleic-acid (OA) -modified silica particles. The resulting macroporous solid materials, known as “poly(merised)Pickering-M/HIPEs,” have a gas permeability of up to 2.6 darcys and are highly interconnected and permeable to hydrocarbons. This paper shows that it is possible to tailor the gas permeability and mechanical performance of the permeable barrier by altering the emulsion internal-phase volume, the volume of surfactant added to the premade Pickering emulsion, and the composition and constituents of the continuous monomer phase; styrene, divinylbenzene (DVB), and poly(ethylene glycol) dimethacrylate were used in the monomer phase.
Teratogenic Effect of Crude Ethanolic Root Bark and Leaf Extracts of Rauwolfia vomitoria (Apocynaceae) on the Liver of Albino Wistar Rat Fetuses
Authors: Eluwa Mokutima A , Ekanem Theresa B , Udoh Paul B , Akpantah Amabe O , Ekong Moses B , Asuquo Olaitan R , Nwakanma Agnes A 
Published: April 2013

Objectives: Rauwolfia vomitoria is a medicinal plant which is used locally for the treatment of a variety of disorders including snake and insect bites and stings, insomnia and insanity. This study was to investigate the teratogenic effect of the ethanolic root bark extract of R. vomitoria on the fetal liver. Material and methods: Twenty-five virgin female Wistar rats weighing between 180 – 200g were used. The animals were divided into 5 groups, labeled A, B, C, D and E, each consisting of 5 rats. Group A rats were the control, while Groups B, C, D and E were the experimental. The female rats at proestrous were mated with sexually matured male rats. The day after was designated as day zero of pregnancy. Groups B and C animals received oral doses of 150mg/kg and 250mg/kg body weight of the root bark extract while groups D and E animals received 150mg/kg and 250mg/kg body weight of the leaf extract respectively from 7th to 11th day of gestation. On the 20th day of gestation, the rats were sacrificed and the fetuses examined for gross anomalies. Each liver was routinely processed using Haematoxylin and Eosin method. Results: Histological observations of the fetal liver showed marked distortion of normal liver architecture in the treated groups when compared with the control, the effect being more pronounced in the groups that received the root bark extract. Conclusions: Our result suggests that ethanolic root bark and leaf extracts of Rauwolfia vomitoria maybe hepatotoxic to the developing rats liver. DOI: http://dx.doi.org/10.3126/ajms.v4i1.6848 Asian Journal of Medical Sciences 4(2013) 30-34
Atmospheric control of sea-ice thickness variability in the Amundsen Gulf, Canadian Beaufort Sea, and over the Labrador Shelf
Authors: Prinsenberg Simon J. , Peterson Ingrid K. , Scott Holladay J. , Galley Ryan J. , Nudds Shannon 
Published: April 2013

AbstractSea-ice thicknesses observed in Canadian coastal waters with helicopter-borne electromagnetic–laser sensors show large interannual variability caused by atmospheric fluctuations in two years for two areas where surveys were repeated, one in the Amundsen Gulf of the Canadian Beaufort Sea and one over the Labrador Shelf. For the Amundsen Gulf, the bimodal ice thickness peaks shifted by 40 cm to thinner thicknesses for the warmer winter of 2008 compared with 2004. The thinner ice in 2008 can be explained partially by reduced thermodynamic ice growth during the warmer winter of 2008. In addition, winds from the east were more persistent throughout the winter of 2008, increasing ice export from the Amundsen Gulf and thereby creating open-water areas where new ice growth in late winter produced the thinner ice classes. For the Labrador Shelf, the mean ice thicknesses of the warmer winter of 2011 (0.71 m) were much less than those of the near-normal winter of 2009 (1.60 m). Again the difference can be explained by the fact that along the entire Labrador Shelf the winter of 2011 was much warmer, reducing ice growth and resulting in thinner ice locally and thinner ice being transported into the survey region from northern latitudes. In addition, northwesterly winds occurred less frequently during the winter of 2011, reducing the transport of relatively thicker ice into the survey area from northern latitudes.
Variability of the climatic mass balance of Vestfonna ice cap, northeastern Svalbard, 1979-2011
Authors: Möller Marco , Finkelnburg Roman , Braun Matthias , Scherer Dieter , Schneider Christoph 
Published: April 2013

AbstractVestfonna ice cap, northeastern Svalbard, is one of the largest ice bodies in the European Arctic, but little is known about the evolution of its mass balance. This study presents a reconstruction of the climatic mass balance of the ice cap for the period 1979/80-2010/11. The reconstruction is based on calculations using a mass-balance model that combines a surface-elevation-dependent accumulation scheme with a spatially distributed temperature-index ablation model that includes net shortwave radiation. Refreezing is included, based on the basic Pmax approach. The model accounts for cloud-cover effects and surface albedo variations that are calculated by a statistical albedo model. ERA-Interim derived air temperature, precipitation and total cloud-cover data are used as input. Results reveal a mean climatic mass-balance rate of +0.09 ± 0.15 m w.e. a–1 for the study period. Annual balances show a slight, insignificant trend towards less positive values over the study period. Refreezing is estimated to contribute about one-third to annual accumulation, and a significant positive trend in refreezing is present over the study period. The modelling results reveal a significant steepening of the climatic mass-balance gradient and indicate a lengthening of the characteristic 3 month ablation period in recent years.
Imaging diagnosis and minimallyinvasive management of necrotizing fasciitis in a dog
Authors: Pivetta M. , Kussy F. , Rossanese M. , Stabile F. , Dennis R. , Holloway A. , Bowlt K. L. 
Published: April 2013

SummaryNecrotising fasciitis is a rapidly progressive, aggressive bacterial infection of the subcutis associated with significant morbidity and mortality in both man and domestic animals. To the best of our knowledge, this is the first veterinary report of magnetic resonance imaging findings in necrotising fasciitis, and the first reported case in a dog to be successfully treated with minimally invasive surgical intervention.
Computed tomographic study of the optimal safe implantation corridors in feline thoraco-lumbar vertebrae
Authors: Bedu A. S. , Manassero M. , Viateau V. , Niebauer G. , Moissonnier P. , Vallefuoco R. 
Published: April 2013

SummaryObjective: To define the implantation corridors in feline thoraco-lumbar vertebrae (T10-L7) using computed tomography (CT) for optimal safe placement of the implants (screws/pins) in spinal column stabilization.Study design: Computed tomographic study.Materials and methods: Computed tomography images of feline spinal column (n = 10) were used to define the optimal safe implantation corridors (OSIC) in the transverse plane. The OSIC were defined as corridors allowing the greatest amount of bone purchase with safe margins for implantation of the bicortical implants. They were characterized by their insertion point, optimal angle (from the midsagital plane), maximum and minimum safe angles (from the same insertion points), length, and width.Results: The OSIC are located within the vertebral bodies. Insertion points were situated at the level of the vertebro-costal joint or the base of the transverse process of the vertebral body for thoracic and lumbar vertebrae, respectively. The mean optimal angle of the OSIC was 90.2° with a maximum deviation angle from optimal angle of 10° dorsally and 8.8° ventrally in thoracic vertebrae, and 90.5° with a maximum deviation angle from the optimal angle of 8.4° dorsally and 7.6° ventrally in lumbar vertebrae.Conclusion and clinical relevance: Corridors drilled in the vertebral body perpendicular to the midsagital plane (90°) or with a small angle (≤10°) of deviation from the optimal angle provide an optimal safe placement of bicortical implants. However, perpendicular implant placement may not always be feasible due to surrounding soft tissue structures.
Microsatellite markers reveal a strong geographical structure in European populations of Castanea sativa (Fagaceae): Evidence for multiple glacial refugia
Authors: Mattioni Claudia , Martin M. Angela , Pollegioni Paola , Cherubini Marcello , Villani Fiorella 
Published: April 2013

• Premise of the study: Large‐scale studies on the genetic diversity of forest trees are relevant for the inventory, conservation, and management of genetic resources and provide an insight into the geographical origins of the species. This approach is appropriate to use with Castanea sativa, a tree of great economic importance and the only species from the genus Castanea in Europe. The history of C. sativa was deduced from fossil pollen data, but the large‐scale genetic structure of this species needs to be elucidated. We evaluated the genetic diversity of C. sativa to define previously unclarified genetic relationships among the populations from Turkey and those from Greece and western Europe. The influence of natural events such as glaciations and human impact in terms of species distribution are discussed.• Methods: Wild chestnut trees (779) were sampled in 31 European sites. Six polymorphic microsatellites were used for the analysis. A set of measures of intra‐ and interpopulation genetic statistics were calculated. The population structure was inferred by using a Bayesian approach.• Key results: The population structure showed a genetic divergence between the eastern (Greek and Turkish) and western (Italian and Spanish) populations. Two gene pools and a zone of gene introgression in Turkey were revealed.• Conclusions: The inferred population structure shows a strong geographical correspondence with the hypothesized glacial refugia and rules out the migration of the chestnut from Turkey and Greece to Italy. The homogeneous gene pool observed in Italy and Spain could have been originated from common refugia along with human‐mediated colonization.
Impact of spatial constraints during seed germination on the evolution of angiosperm cotyledons: A case study from tropical Hydatellaceae (Nymphaeales)
Authors: Sokoloff Dmitry D. , Remizowa Margarita V. , Beer Anton S. , Yadav Shrirang R. , Macfarlane Terry D. , Ramsay Margaret M. , Rudall Paula J. 
Published: April 2013

• Premise of the study: A bipolar embryo with cotyledons is a characteristic feature that appeared early in the evolution of seed plants. Cotyledon number is an important character in angiosperm classification. We explore the links between functional aspects of seed germination and the number and location of the cotyledons, using as a model the early‐divergent angiosperm family Hydatellaceae, in which seedlings are superficially monocot‐like.• Methods: Seedlings of two species of tropical Hydatellaceae were studied using light and scanning electron microscopy.• Key results: Seedlings of Trithuria cowieana bear two free cotyledons. Each cotyledon possesses a green, filiform, vascularized blade that resembles subsequent leaves, and a basal, nonvascularized, haustorial outgrowth that remains in close contact with the endosperm. Seedlings of Trithuria konkanensis have two free cotyledonary haustoria inserted close to each other and a leaf blade probably belonging to one of the cotyledons. The cotyledonary node elongates between the haustoria and the leaf blade to form a mesocotyl.• Conclusions: To date, the absence or presence of a cotyledonary tube represents the only known qualitative morphological difference between the two major clades of Hydatellaceae. Cotyledons with a haustorium and leaf blade are unusual at the scale of seed plants and probably evolved due to homeosis. The mesocotyl of T. konkanensis resembles that of grasses and sedges. Seedling diversity in Hydatellaceae and other seed plants is linked with the principal physical and spatial constraint of their embryo structure, with the primary root and shoot apical meristems located at opposite poles, and haustorial cotyledon tips.
New microsatellite markers for Tricyrtis macrantha (Convallariaceae) and cross‐amplification in closely related species
Authors: Ohki Noriko , Setoguchi Hiroaki 
Published: April 2013

• Premise of the study: Microsatellite markers were characterized in Tricyrtis macrantha (sect. Brachycyrtis, Convallariaceae), a vulnerable species endemic to Japan, to investigate its genetic diversity and population structure.• Methods and Results: Eleven microsatellite markers were developed. The number of alleles per locus ranged from one to seven, and genetic diversity per locus ranged from 0.142 to 0.812. Four markers were successfully amplified in other species of sect. Brachycyrtis (T. ishiiana, T. ishiiana var. surugensis, and T. macranthopsis).• Conclusions: The microsatellite markers can be used to investigate the genetic diversity and population structure of the vulnerable and endangered species of Tricyrtis sect. Brachycyrtis, to aid in the development of conservation strategies for each species.
Development of microsatellite loci for the riparian tree species Melaleuca argentea (Myrtaceae) using 454 sequencing
Authors: Nevill Paul G. , Williams Anna , Krauss Siegfried , Bradbury Donna , Samaraweera Sunil , Gardner Michael G. 
Published: April 2013

• Premise of the study: Microsatellite primers were developed for Melaleuca argentea (Myrtaceae) to evaluate genetic diversity and population genetic structure of this broadly distributed northern Australian riparian tree species.• Methods and Results: 454 GS‐FLX shotgun sequencing was used to obtain 5860 sequences containing putative microsatellite motifs. Two multiplex PCRs were optimized to genotype 11 polymorphic microsatellite loci. These loci were screened for variation in individuals from two populations in the Pilbara region, northwestern Western Australia. Overall, observed heterozygosities ranged from 0.27 to 0.86 (mean: 0.52) and the number of alleles per locus ranged from two to 13 (average: 4.3).• Conclusions: These microsatellite loci will be useful in future studies of the evolutionary history and population and spatial genetic structure in M. argentea, and inform the development of seed sourcing strategies for the species.
Les paradoxes de l'institutionnalisation de la lutte contre la pauvreté en France
Authors: Viguier Frédéric 
Published: April 2013

Pour lutter contre la pauvreté et l’exclusion sociale qui augmentent dans les années 1980 en raison de la croissance du chômage et du sous-emploi, la France transforme son système de protection sociale. A côté des assurances sociales liées à l’emploi salarié stable, se met en place un système spécifique, subsidiaire, universel et minimal. Ce système vise en théorie à réparer les assistés ; il ménage un rôle important aux avocats des personnes pauvres ; il s’appuie sur une information économique et sociale qui scrute les dispositifs et leurs bénéficiaires. Près de trois décennies plus tard, le système n’a pas enrayé la pauvreté. Pire, il contribue à stigmatiser celles et ceux qui la vivent. L’argent des pauvres reste rare et insuffisant. S’il remédie aux pires situations de pauvreté, il fait aussi l’objet de soupçons d’intempérance et de contrôles accentués.
Entre « quantitatif » et « qualitatif ». Comment les investisseurs professionnels évaluent les gérants d'actifs financiers
Authors: de Larminat Pierre 
Published: April 2013

Pour rendre compte de leurs placements, les investisseurs professionnels mobilisent des dispositifs d’analyse censés leur permettre de domestiquer l’incertitude financière. Ils les classent selon qu’ils sont « quantitatifs » ou « qualitatifs ». Cette représentation de leurs pratiques correspond aux ressources qu’ils ont acquises par socialisation et à la division sociale du travail d’analyse financière. En revanche, elle ne rend compte ni du sens technique des opérations d’analyse ni de la relation fonctionnelle qui les unit les unes aux autres. De ce fait, la forme de classification « quantitatif/qualitatif » opacifie les procédures d’analyse et préserve les professionnels de l’investissement du contrôle des fractions les moins initiées de leur clientèle.
Payerne VD, Abbatiale. Kapitelsaal und Marienkapelle – Stand der Forschung
Authors: Faccani Guido 
Published: April 2013

La recherche archéologique et les études sur l’histoire architecturale de l’abbatiale de Payerne menées dès le xixe siècle, montrent toute l’importance de cette église dans l’architecture sacrée romane précoce. Depuis longtemps, on sait qu’à Payerne existait au vie siècle tardif un oratoire dédié à Sainte-Marie. Celui-ci n’a pas été localisé jusqu’à présent. Entre autres, à cause du fond très réduit des sources écrites, l’acte de la fondation du monastère clunisien dans la deuxième moitié du xe siècle reste à quelques détails près encore obscur. De même, il n’a pas été élucidé s’il existait autrefois une chapelle mariale à l’est de la salle capitulaire. Des études récentes démontrent, que la salle capitulaire est plus ancienne que le transept et le chevet existant. Le décor architectural de la salle date vraisemblablement de la première moitié du xie siècle. Avec les autres éléments architecturaux, le plan d’ensemble du monastère peut être reconstitué ; il présente des ressemblances avec celui de Villars-les-Moines.
Acrylic copolymers crosslinked by click chemistry: Some aspects of synthesis, curing, and crosslinking
Authors: Sukumaran Smitha C. , Sunitha K. , Mathew Dona , Reghunadhan Nair C. P. 
Published: April 2013

ABSTRACTAcrylic polymers bearing pendant azide and propargyl groups were synthesized by chemical transformation of epoxy‐ and carboxylic functional acrylic precursor polymers and were characterized. These copolymers were crosslinked by reacting them in the presence of Cu(I) catalyst via the azide–alkyne click reaction leading to triazole networks. Influence of catalyst concentration on the crosslinking cure kinetics was investigated, and the activation parameters were evaluated. The activation energy decreased from 90 kJ mol−1 to 25 kJ mol−1 on catalyzing the cure reaction as estimated by Ozawa method. Differential scanning calorimetric analysis indicated thermal decomposition of the residual azide groups at around 200–220°C, which was catalyzed by Cu(I) with associated activation energy of 130–94 kJ mol−1. Isothermal cure reaction and decomposition of the azide groups were predicted using these parameters. Estimation of crosslink density by solvent swelling and dynamic mechanical analyses showed a normal crosslinking behavior. While the solvent swelling rate and the equilibrium swelling decreased, the front factor and diffusion coefficient of swelling showed a transition from non‐Fickian to Fickian as the triazole concentration increased in the network. The click reaction offered an alternate means to crosslink acrylate polymers. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1289‐1300, 2013