New Materials (new + material)

Distribution by Scientific Domains
Distribution within Polymers and Materials Science


Selected Abstracts


ChemInform Abstract: Li3V(MoO4)3: A New Material for Both Li Extraction and Insertion.

CHEMINFORM, Issue 33 2010
D. Mikhailova
Abstract The title compound is prepared from stoichiometric mixtures of Li2MoO4, MoO3, and V2O3 (Ar, silica tube, 813 K, 30 h) and characterized by single crystal XRD, electrochemical measurements, XPS, and magnetic measurements. [source]


ChemInform Abstract: A New Material for Hydrogen Storage; ScAl0.8Mg0.2.

CHEMINFORM, Issue 6 2010
Martin Sahlberg
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


ChemInform Abstract: Synthesis, Structure and Characterization of Fe0.50Ti2(PO4)3: A New Material with Nasicon-Like Structure.

CHEMINFORM, Issue 6 2008
S. Benmokhtar
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


Studies on a New Material for Hydrogen Storage and Supply by Modified Fe and Fe2O3 Powder

CHINESE JOURNAL OF CHEMISTRY, Issue 7 2007
Hui Wang
Abstract Modified iron oxide, a new material for hydrogen storage and supply to polymer electrolyte fuel cell (PEFC), was prepared by impregnating Fe or Fe2O3 powder with an aqueous solution containing metal cation additives (Al, Cr, Ni, Co, Zr and Mo). Hydrogen storage properties of the samples were investigated. The results show that both Fe and Fe2O3 powder with additive Mo presented excellent catalytic activity and cyclic stability, and their hydrogen producing temperature could be surprisingly decreased. The temperature of forming hydrogen for the Fe2O3 -Mo at the rate of 250 µmol·min,1·Fe-g,1 could be dramatically decreased from 527 °C before addition of Mo to 283 °C after addition of Mo in the fourth cycle. The cause for it was probably related to preventing the sinter of the sample particles. In addition, hydrogen storage capacity of the Fe2O3 -Mo can reach w=4.5% (72 kg H2/m3), close to International Energy Agency (IEA) criterion. These show the value of practical application of the Fe2O3 -Mo as the promising hydrogen storage material. [source]


Cover Picture: (Adv. Eng.

ADVANCED ENGINEERING MATERIALS, Issue 5 2010
Mater.
The INM - Leibniz Institute for New Materials in Saarbruecken engages in fundamental and applied materials research-from a chemical, physical and biological perspective. The cover highlights examples of INM's research which is presented in this special issue. The front cover shows biomineralization using the example of crystals embedded in the outer tissue of onion bulbs (courtesy of Birgit Heiland, INM). The back side demonstrates an in situ adhesion experiment in a scanning electron microscope (courtesy of Andreas S. Schneider/Anika Weber, INM). [source]


New Materials in Memory Development Sub 50,nm: Trends in Flash and DRAM

ADVANCED ENGINEERING MATERIALS, Issue 6 2009
Karl Heinz Kuesters
No abstract is available for this article. [source]


New Materials in Memory Development Sub 50,nm: Trends in Flash and DRAM,

ADVANCED ENGINEERING MATERIALS, Issue 4 2009
Karl Heinz Kuesters
New materials are of key importance for scaling memories in the sub 50,nm generations. Currently high- k materials and metal gates are investigated for usage in Flash and DRAM memory. However, the requirements in the applications are different, leading to different material combinations. This paper gives an overview on new materials with focus on memory applications. [source]


Epoxy Polymers New Materials and Innovations

MACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 16 2010
József Karger-Kocsis
No abstract is available for this article. [source]


3rd Workshop on Semiconductor Nanodevices and Nanostructured Materials (NanoSemiMat-3)

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue S2 2004
E. F. da Silva Jr.
The 3rd Workshop on Semiconductor Nanodevices and Nanostructured Materials (NanoSemiMat-3) took place in Salvador, Bahia, Brazil, 24,27 March 2004. The NanoSemiMat network is part of the Brazilian Initiative on Nanoscience and Nanotechnology (N&N). The papers include the following topics: Photodetectors, Lasers and LEDs, Porous Materials, New Materials, New Technologies, Molecular Technology and Interfaces, Nanostructured Materials and Nanobiotechnology. The presentations reflect theoretical and experimental research on nanostructured semiconductor materials such as III,V and II,VI, Si and SiC based nanodevices, wide gap materials, ceramics, polymers, porous materials, optical and transport properties of low-dimensional structures, magnetic nanostructures and structures under the influence of high fields, spintronics and sensor applications. This issue is devoted to Prof. J. R. Leite, Sao Paulo, former Regional Editor of physica status solidi and Guest Editor in memoriam of the present Proceedings. [source]


Preface: phys. stat. sol. (c) 1/S2

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue S2 2004
E. F. da Silva Jr.
The papers in this special issue of physica status solidi (c) are selected manuscripts including diverse research lines presently in development in the ambit of the NanoSemiMat network in Brazil. The 3rd Workshop on Semiconductor Nanodevices and Nanostructured Materials (NanoSemiMat-3) took place in Salvador, Bahia, Brazil, at the Catussaba Resort Hotel, during the period of 24,27 March 2004. The NanoSemiMat network is part of the Brazilian Initiative on Nanoscience and Nanotechnology (N&N), with strategic cooperative research support in this area. The initiative started in 2001, through the formation of four research networks nationwide in different scientific fields associated to NanoScience and Nanotechnology (N&N). The 3rd Workshop on Nanodevices and Nanostructured Materials (NanoSemiMat-3) is an evolution of the two previous meetings which were held in Recife, PE, Brazil and Natal, RN, Brazil in 2002 and 2003, respectively. The meeting comprised 16 invited plenary talks, each 30 minutes long, given by eminent researchers from Brazil, Canada, France, Germany and the United States of America. These invited talks extend through different topics of N&N associated to Nanodevices and Nanostructured Materials: Photodetectors, Lasers and LEDs, Porous Materials, New Materials, and New Technologies, among others. There were short talks presented by representatives of the other N&N networks in Brazil dealing with Molecular Technology and Interfaces, Nanostructured Materials and Nanobiotechnology. Also a poster session, with about 60 presentations, highlighted the main research activities presently being developed by the network members at the different sites which constitute the NanoSemiMat network. The presentations reflected theoretical and experimental research lines which lead to the development of basic and applied research in nanostructured semiconductor materials such as III,V and II,VI, Si and SiC based nanodevices, wide gap materials, ceramics, polymers, porous materials, optical and transport properties of low dimensional structures, magnetic nanostructures and structures under the influence of high fields, spintronics and sensor applications. The participants of the workshop came from 20 research institutions within Brazil and from 7 research laboratories and universities in Europe and North America. In total about 120 researchers, members of the network, invited researchers, representatives of supporting and funding agencies in Brazil, undergraduate and graduate students, technical staff and supporting personal as well as researchers from complementary fields were present. The realization of the NanoSemiMat-3 was possible due to the financial support of the Brazilian Ministry of Science and Technology (MCT) and the Brazilian National Research Council (CNPq) and the logistic support of Federal University of Bahia. All activities during the NanoSemiMat-3 were open to the general public with interest in nanoscience and nanotechnology. In this third workshop of the series, we highlight the expansion of its format, with plenary and invited talks, poster sessions, as well as the presence of seven invited speakers from abroad. We expect that the continuation of the NanoSemiMat series will be a forum for discussions of state-of-the-art research developed in Brazil on N&N and the multidisciplinary field of semiconductor nanodevices and nanostructured materials as well as its superposition to other branches of science. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


New Materials Based on Renewable Resources: Chemically Modified Expanded Corn Starches as Catalysts for Liquid Phase Organic Reactions.

CHEMINFORM, Issue 10 2003
Shinichi Doi
No abstract is available for this article. [source]


Late Devonian tetrapod remains from Red Hill, Pennsylvania, USA: how much diversity?

ACTA ZOOLOGICA, Issue 2009
Edward B. Daeschler
Abstract The remains of Late Devonian tetrapods from the Red Hill locality in Pennsylvania help to elucidate the early stages of tetrapod evolution. Red Hill is a particularly informative site that preserves a diverse fauna and flora within a depositional setting suggesting penecontemporaneous deposition of locally derived material. Here, for the first time, we report on the full suite of early tetrapod remains from Red Hill and consider the implications for tetrapod diversity within the Red Hill ecosystem. Previously described material is reviewed and considered in relation to newly reported specimens. New material described includes isolated skull elements (two jugals, a postorbital, a lacrimal and a coronoid) and postcranial elements (a femur and a gastral scale). The characteristics of many of the Red Hill tetrapod specimens conform to the morphological expectations of Late Devonian forms. Several elements, however, illustrate more derived characteristics and strongly suggest the presence of the oldest known whatcheeriid-like tetrapod. This study demonstrates the difficulty in making taxonomic associations with isolated remains, even when found in close proximity to one another. Exploration of the characteristics of each element, however, demonstrates the presence of at least three early tetrapod taxa at the Red Hill site. [source]


A LONG-SNOUTED DYROSAURID (CROCODYLIFORMES, MESOEUCROCODYLIA) FROM THE PALEOCENE OF MOROCCO: PHYLOGENETIC AND PALAEOBIOGEOGRAPHIC IMPLICATIONS

PALAEONTOLOGY, Issue 2 2008
STEPHANE JOUVE
Abstract:, New material of a long-snouted dyrosaurid has been discovered in the Paleocene of Morocco. It consists of a well-preserved skull with embedded mandible and four dorsal vertebrae. The particularly elongate snout, proportionally the longest of all known dyrosaurids, allows precise identification of this material as Atlantosuchus coupateziBuffetaut, 1979a, and presentation of an emended diagnosis for this species previously known only from a mandibular symphysis. A phylogenetic analysis of the dyrosaurids indicates a close relationship between A. coupatezi and Rhabdognathus. It also confirms a previous hypothesis that Congosaurus is distinct from Hyposaurus. It is more closely related to Atlantosuchus than Hyposaurus. The analysis also allows palaeobiogeographic interpretations to be made. Dyrosaurids ranged from North Africa to other areas. They were rare during the Maastrichtian and endemic to each continent at this time. Competition with large marine reptiles, such as mosasaurs, limited their dispersal during the Late Cretaceous. The disappearance of these rivals during the ,K-T crisis' enabled their diversification and widespread dispersal during the Paleocene, with the same genera present on several continents. [source]


Redescription of Lagenophrys cochinensis Santhakumari & Gopalan, 1980 (Ciliophora, Peritrichia, Lagenophryidae), an Ectosymbiont of Marine Isopods, Including New Information on Morphology, Geographic Distribution, and Intraspecific Variation

THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 1 2006
JOHN C. CLAMP
ABSTRACT. Lagenophrys cochinensis is a peritrich ciliate originally reported as an ectocommensal of the wood-boring isopods Sphaeroma terebrans, Sphaeroma triste, and Sphaeroma annandalei and the tanaidacean Apseudes chilkensis in estuaries of southern India. In the present study, it was found to occur also on Sphaeroma quoyanum, Sphaeroma walkeri, and Exosphaeroma planulum. New material was used to make permanent preparations, allowing a comprehensive description of the morphology of L. cochinensis for the first time. The macronucleus of L. cochinensis was found to have an elongate shape that spans the width of the cell body, unlike the compact macronucleus originally described. In addition, the loricae of all samples examined were subcircular or shorter than wide, not longer than wide as originally described. Polykinetid 3 of the infundibular infraciliature consisted of three rows of kinetosomes, only the third species of Lagenophrys found to have more than two rows in polykinetid 3 so far. Samples of L. cochinensis on S. quoyanum from New Zealand and California appeared to represent a population distinct from others. The species has a cosmopolitan distribution, probably owing to the ease with which its hosts are transported from one estuary to another in drifting wood or on hulls of ships. [source]


New Materials in Memory Development Sub 50,nm: Trends in Flash and DRAM,

ADVANCED ENGINEERING MATERIALS, Issue 4 2009
Karl Heinz Kuesters
New materials are of key importance for scaling memories in the sub 50,nm generations. Currently high- k materials and metal gates are investigated for usage in Flash and DRAM memory. However, the requirements in the applications are different, leading to different material combinations. This paper gives an overview on new materials with focus on memory applications. [source]


Synthesis of Core,Shell Inorganic Nanotubes

ADVANCED FUNCTIONAL MATERIALS, Issue 15 2010
Ronen Kreizman
Abstract New materials and techniques pertaining to the synthesis of inorganic nanotubes have been ever increasing since the initiation of the field in 1992. Recently, WS2 nanotubes, which are produced now in large amounts, were filled with molten lead iodide salt by a capillary wetting process, resulting in PbI2@WS2 core,shell nanotubes. This work features progress in the synthesis of new core,shell nanotubes, including BiI3@WS2 nanotubes produced in a similar same manner. In addition, two new techniques for obtaining core,shell nanotubes are presented. The first is via electron-beam irradiation, i.e., in situ synthesis within a transmission electron microscope. This synthesis results in SbI3 nanotubes, observed either in a hollow core of WS2 ones (SbI3@WS2 nanotubes), or atop of them (WS2@SbI3 nanotubes). The second technique involves a gaseous phase reaction, where the layered product employs WS2 nanotubes as nucleation sites. In this case, the MoS2 layers most often cover the WS2 nanotube, resulting in WS2@MoS2 core,shell nanotubes. Notably, superstructures of the form MoS2@WS2@MoS2 are occasionally obtained. Using a semi-empirical model, it is shown that the PbI2 nanotubes become stable within the core of MoS2 nanotubes only above a critical core diameter of the host (>12,nm); below this diameter the PbI2 crystallizes as nanowires. These model calculations are in agreement with the current experimental observations, providing further support to the growth mechanism of such core,shell nanotubes. [source]


Co2MnSi as full Heusler alloy ferromagnetic electrode in magnetic tunneling junctions

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 5 2006
G. Reiss
Abstract The discoveries of antiferromagnetic coupling in Fe/Cr multilayers by Grünberg, the Giant MagnetoResistance by Fert and Grünberg and a large tunneling magnetoresistance at room temperature by Moodera have triggered enormous research on magnetic thin films and magnetoelectronic devices. Large opportunities are especially opened by the spin dependent tunneling resistance, where a strong dependence of the tunneling current on an external magnetic field can be found. In order to obtain large magnetoresistance effects, materials with strongly spin polarized electron gas around the Fermi level have to be found. New materials with potentially 100% spin polarization will be discussed using the example of the full Heusler compound Co2MnSi. First, experimental aspects of the integration of this alloy in magnetic tunneling junctions will be addressed. With these junctions, we obtain up to 100% TMR at low temperature. The current status of this research will then be summarized with special regard to the complex diffusion mechanisms occurring in these devices and to the properties of the interfaces between the Heusler material and the insulator. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


Investigation of basalt fiber composite aging behavior for applications in transportation,

POLYMER COMPOSITES, Issue 5 2006
Qiang Liu
New materials such as basalt fiber offer the promise of innovative applications in transportation because of documented strengths (V. Ramakrishnan, N.S. Tolmare, and V. Brik, "NCHRP-IDEA Program Project Final Report, " Transportation Research Board, Washington, DC, (1998)). Previously, we found that mechanical properties of basalt twill fabric-reinforced polymer composites were comparable to composites reinforced with glass fabrics of similar structures [Q. Liu, M.T. Shaw, R.S. Parnas, and A.M. McDonnell, Polymer Composites, 27(1), 41 (2006)]. Use in transportation also requires knowledge of environmental durability. This study reports the tolerance of basalt-fiber-reinforced polymer composites to salt water immersion, moisture absorption, temperature, and moisture cycling. Parallel tests were conducted for the corresponding glass-reinforced polymer composites. Aging for 240 days in salt water or water decreased the Young's modulus and tensile strength of basalt composites slightly but significantly (p < 0.05). Freeze-thaw cycling up to 199 cycles did not change the shear strength significantly, but aging in hot (40°C) salt water or water did decrease the shear strength of basalt composites (p < 0.05). The aging results indicate that the interfacial region in basalt composites may be more vulnerable to damage than that in glass composites. POLYM. COMPOS., 27:475,483, 2006. © 2006 Society of Plastics Engineers [source]


Archaeopteris halliana from the Late Devonian (Famennian) of Anhui Province, China

ACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 3 2009
Yun GUO
Abstract: New materials from the Upper Devonian (Famennian) Wutong Formation of Chizhou District, Anhui Province, South China, allow description of fertile and sterile characters of Archaeopteris halliana. This plant has penultimate axes attached by sterile leaves and paired ultimate branches in the same ontogenetic spiral. Sterile leaves are narrowly cuneate in shape and bear distal margins dissected deeply. These leaves are spirally arranged on sterile ultimate axes. Non-laminated sporophylls occur spirally on the ultimate axes and bifurcate once or twice. Elongate sporangia with longitudinal dehiscence are borne adaxially below or above the dividing points of the sporophylls. Despite the leaf shape resembling that of Archaeopteris macilenta, our plant is assigned to A. halliana because of its non-laminated sporophylls. Fertile characters should be given priority or enough consideration in identifying species of Archaeopteris. [source]


The use of porous calcium phosphate scaffolds with transforming growth factor beta 1 as an onlay bone graft substitute

CLINICAL ORAL IMPLANTS RESEARCH, Issue 6 2004
An experimental study in rats
Abstract Objectives: Autogeneous bone grafting is regarded to be the golden standard for onlay grafts, but it requires a harvesting procedure and the remodeling pattern over time is unpredictable. New materials are constantly being sought to overcome these problems. An in vivo experiment was carried out to evaluate whether (1) porous calcium phosphate cement is a suitable biomaterial for onlay bone grafting, and (2) the addition of transforming growth factor beta 1 (TGF-,1) accelerates de novo bone formation inside the cement porosity. Material and methods: A carrier of porous calcium phosphate cement (Calcibon®) was designed and 16 rats received one preshaped implant each. In 8 out of 16 implants 0.75 ,g TGF-,1 was applied. The animals were killed after 4 weeks and the characteristics of tissue ingrowth into the onlay graft were evaluated. Results: Histologic and quantitative histomorphometrical measurements demonstrated osteoid-like tissue formation in both experimental groups. The addition of TGF-,1 did not induce significantly more osteoid-like tissue formation. On the other hand, in TGF-,-loaded implants, a higher number of pores contained an inflammatory infiltrate. Conclusion: This study indicated that porous calcium phosphate cement is a promising material for clinical situations where bone formation has to be supported. Résumé La greffe osseuse autogčne est considérée comme la meilleure technique actuelle pour les greffons onlay mais elle requiert un processus de prélevement et le remodelage qui s'en suit est imprévisible. De nouveaux matériaux sont donc constamment recherchés. Cette étude in vitro a essayé d'évaluer si 1) le cément phosphate calcium poreux était un biomatériel favorable pour le greffage osseux onlay, 2) si l'addition de TGF-,1 accélérait la néoformation osseuse ŕ l'intérieur de la porosité du cément. Un porteur de cément phosphate calcium poreux (Calcibon®) a été fabriqué et seize rats ont reçu chacun un implant prédécoupé. Au niveau de huit des seize implants 0,75 ,g de TGF ,1 a été appliqué. Les animaux ont été euthanasiés aprčs quatre semaines et les caractéristiques de la croissance interne tissulaire dans le greffon onlay ont étéévaluées. Les mesures histologiques et histomorphométriques quantitatives ont démontré une formation tissulaire semblable ŕ l'ostéogénie dans les deux groupes expérimentaux. L'addition de TGF-ß1 n'induisait pas plus de formation tissulaire ressemblant ŕ celle d'ostéogénie. D'un autre côté, dans les implants chargés de TGF-,1, un nombre plus important de pores contenaient un infiltrat inflammatoire. Cette étude indique que le cément phosphate calcium poreux est un matériau prometteur pour les situations cliniques dans lesquelles la formation osseuse doit ętre améliorée. Zusammenfassung Ziel: Die Transplantation von autologem Knochen wird heute als Goldstandard für die Onlay-Transplantate betrachtet. Es braucht dazu aber einen zusätzlichen Eingriff für die Entnahme und eine Prognose bezüglich der anschliessenden Remodellationsvorgänge sind kaum möglich. Man sucht ständig nach neuen Produkten, um diese Probleme zu überwinden. Man führte eine in vivo Studie durch und untersucht, ob (1) ein poröser Kalziumphosphatzement ein brauchbares Biomaterial für ein Onlay-Transplantat ist, und (2) der Zusatz von TGF-,1 die Neubildung von Knochen in den Porositäten des Zementes positiv beeinflusst. Material und Methode: Man entwickelte einen Trägerzement aus porösem Kalziumphosphat (Calcibon®) und 16 Ratten erhielten je ein vorgeformtes Implantat eingesetzt. Bei 8 der 16 Implantate fügte man zusätzlich 0.75 ,g TGF-,1 dazu. Vier Wochen später opferte man die Tiere und konnte nun die Charakteristika des in die Implantate einwachsenden Gewebes untersuchen. Resultate: Die histologischen und quantitativen histomorphometrischen Messungen zeigten in beiden experimentellen Gruppen osteoidähnliche Gewebsbildungen. Der Zusatz von TGF-,1 bewirkte keine signifikante Zunahme dieser osteoidähnlichen Gewebsbildungen. Die mit TGF-,1 durchsetzten Implantate enthielten aber mehr mit entzündlichem Infiltrat angefüllte Poren. Zusammenfassung: Diese Arbeit zeigte uns, dass ein poröser Kalziumphosphatzement bei klinischen Situationen, wo die Knochenbildung unterstützt werden muss, ein erfolgsversprechendes Material ist. Resumen Objetivos: El injerto de hueso autógeno está considerado como el estándar de oro para injertos superpuestos, pero requiere un procedimiento de recolección y el patrón de remodelado a lo largo del tiempo es impredecible. Constantemente se están buscando materiales nuevos para superar estos problemas. Se llevó a cabo un experimento in vivo para evaluar si (1) el cemento de fosfato cálcico poroso es un biomaterial apropiado para injerto óseo superpuesto, y (2) la adición de TGF-,1 acelera la formación de hueso de novo dentro de la porosidad del cemento. Material y Métodos: Se diseńó un portador de cemento de fosfato cálcico (Calcibon®) y 16 ratas recibieron un implante preformado cada una. En 8 de 16 implantes se aplicaron 0.75 ,g de TGF-,1. Los animales se sacrificaron tras 4 semanas y se evaluaron las características del tejido crecido hacia adentro del injerto superpuesto. Resultados: Las mediciones histológicas e histomorfométricas cuantitativas demostraron formación de tejido tipo osteoide en ambos grupos experimentales. La adición de TGF-,1 no indujo significativamente más formación de tejido tipo osteoide. Por otro lado, en los implantes cargados con TGF-,1, un mayor número de de poros contenían infiltrado inflamatorio. Conclusión: Este estudio indica que el cemento de fosfato cálcico poroso es un material prometedor para situaciones clínicas donde la formación de hueso ha de ser favorecida. [source]


Synthesis, characterization and impedance spectroscopy of the new material [(CH3) (C6H5) 3P] 2CoBr4: a member of the A2BX4 family

CRYSTAL RESEARCH AND TECHNOLOGY, Issue 5 2008
M. F. Mostafa
Abstract The crystal structure of bis-(methyltriphenylphosphonium) tetrabromocobaltate (II), [(C19H18P)2 CoBr4] is determined: Mr = 933.203, monoclinic, P21, a = 9. 6977 (3) Ĺ, b = 12.5547 (4)Ĺ, c = 16.4503 (6)Ĺ, , = 105.603 (2)°, V = 1929.04 (11)Ĺ3, Z = 2, Dx = 1.607 Mg m -3, T = 298 K. Differential thermal analysis at high temperatures shows three endothermic peaks characterizing four phases, with onset temperatures at T1= 313±2 K, T2 = 320±4 K and T3= 360±1 K. The structural instability detected via the temperature dependence of permittivity at T1 is ascribed to order-disorder transition associated with cation dipole reorientation. Permittivity and ac conductivity studies as a function of temperature (295 K-375 K) and frequency (0.11 kHz < f <100 kHz) are presented. The results indicate the importance of the cation size and shape on the phase transitions in the system. Bulk conductivity behavior is thermally activated. The associated activation energies are in the range 2.9 to 1.0 eV depending on the temperature regime. Two contributions to the ac conductivity, one dominating at low temperatures and high frequencies which are characterized by superlinear frequency exponent and the second dominates at high temperatures characterized by a sublinear frequency exponent. The behavior is interpreted in terms of the jump relaxation model. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


STORIES AND COSMOGONIES: Imagining Creativity Beyond "Nature" and "Culture"

CULTURAL ANTHROPOLOGY, Issue 2 2009
STUART McLEAN
ABSTRACT What does it mean to create? Who or what could be said to create? God? Artists? Evolution? Markets? The Dialectic? Do things "just happen" and if so is that a kind of creativity? Taking storytelling as its point of reference, this essay considers the notion of creativity as it applies both to the productions of the human imagination, especially stories, and to the self-making of the material universe. I define creativity broadly as the bringing forth of new material, linguistic, or conceptual formations or the transformation of existing ones and as calling, not for a "cultural poetics," but for a more broadly conceived poetics of making (poesis, in its most inclusive sense), encompassing both the natural and cultural realms as conventionally designated, a poetics capable of articulating the stories human beings tell with cosmogonies detailing the coming-to-being of the physical universe. Extending the purview of creativity beyond the human realm to include the processes shaping the material universe allows us to envision creativity itself in terms of a generative multiplicity that resists articulation in binary oppositional terms and that demands therefore to be thought as ontologically prior to any possible differentiation between the domains of nature and culture, or between reality and its cultural,linguistic representations, challenging us to reimagine not only the relationship between nature and culture but also the problematic of representation that continues to inform much work in the humanities and social sciences. Such a reimagining might proceed precisely from an enlarged understanding of creativity,and in particular of storytelling,and I consider some of the epistemic and writerly implications of this claim for anthropology as a discipline concerned preeminently with exploring and documenting the varieties of human being-in-the-world. [source]


A Short-Term Bioresorbable Bone Filling Material Based on Hydroxyapatite, Chitosan, and Oxidized Starch Tested in a Novel Orthotopic Metaphyseal Mouse Model,

ADVANCED ENGINEERING MATERIALS, Issue 8 2009
Elias Volkmer
Despite significant advances in orthopedic surgery, no perfect bioresorbable bone-filling material has yet been clinically established. A new candidate material based on hydroxyapatite, chitosan and oxidised starch, which has the potential to covalently bind to bone in a watery milieu was tested in a new murine model. A special focus lies on the in vivo biocompatibility and bioresorbability of the new material. [source]


Multifunctional Triphenylamine/Oxadiazole Hybrid as Host and Exciton-Blocking Material: High Efficiency Green Phosphorescent OLEDs Using Easily Available and Common Materials

ADVANCED FUNCTIONAL MATERIALS, Issue 17 2010
Youtian Tao
Abstract A new triphenylamine/oxadiazole hybrid, namely m -TPA- o -OXD, formed by connecting the meta -position of a phenyl ring in triphenylamine with the ortho -position of 2,5-biphenyl-1,3,4-oxadiazole, is designed and synthesized. The new bipolar compound is applicable in the phosphorescent organic light-emitting diodes (PHOLEDs) as both host and exciton-blocking material. By using the new material and the optimization of the device structures, very high efficiency green and yellow electrophosphorescence are achieved. For example, by introducing 1,3,5-tris(N -phenylbenzimidazol-2-yl)benzene (TPBI) to replace 2, 9-dimethyl-4,7-diphenyl-1, 10-phenanthroline (BCP)/tris(8-hydroxyquinoline)aluminium (Alq3) as hole blocking/electron transporting layer, followed by tuning the thicknesses of hole-transport 1, 4-bis[(1-naphthylphenyl)amino]biphenyl (NPB) layer to manipulate the charge balance, a maximum external quantum efficiency (,EQE,max) of 23.0% and a maximum power efficiency (,p,max) of 94.3 lm W,1 are attained for (ppy)2Ir(acac) based green electrophosphorescence. Subsequently, by inserting a thin layer of m -TPA- o -OXD as self triplet exciton block layer between hole-transport and emissive layer to confine triplet excitons, a ,EQE,max of 23.7% and ,p,max of 105 lm W,1 are achieved. This is the highest efficiency ever reported for (ppy)2Ir(acac) based green PHOLEDs. Furthermore, the new host m -TPA- o -OXD is also applicable for other phosphorescent emitters, such as green-emissive Ir(ppy)3 and yellow-emissive (fbi)2Ir(acac). A yellow electrophosphorescent device with ,EQE,max of 20.6%, ,c,max of 62.1 cd A,1, and ,p,max of 61.7 lm W,1, is fabricated. To the author's knowledge, this is also the highest efficiency ever reported for yellow PHOLEDs. [source]


Diamond Transistor Array for Extracellular Recording From Electrogenic Cells

ADVANCED FUNCTIONAL MATERIALS, Issue 18 2009
Markus Dankerl
Abstract The transduction of electric signals from cells to electronic devices is mandatory for medical applications such as neuroprostheses and fundamental research on communication in neuronal networks. Here, the use of diamond with its advantages for biological applications as a new material for biohybrid devices for the detection of cell signals is investigated. Using the surface conductivity of hydrogen-terminated single-crystalline diamond substrates, arrays of solution-gate field-effect transistors were fabricated. The characterization of the transistors reveals a good stability in electrolyte solutions for at least 7 days. On these devices, cardiomyocyte-like HL-1 cells as well as human embryonic kidney cells (HEK293), which were stably transfected with potassium channels, are cultured. Both types of cells show healthy growth and good adhesion to the substrate. The diamond transistors are used to detect electrical signals from both types of cells by recording the extracellular potential. For the HL-1 cells, the shape of action potentials can be resolved and the propagation of the signal across the cell layer is visible. Potassium currents of HEK293 cells are activated with the patch-clamp technique in voltage-clamp mode and simultaneously measured with the field-effect transistors. The ion sensitivity of the diamond surface enables the detection of released potassium ions accumulated in the cleft between transistor and cell. [source]


Development and Testing of Energetic Materials: The Concept of High Densities Based on the Trinitroethyl Functionality

ADVANCED FUNCTIONAL MATERIALS, Issue 3 2009
Michael Göbel
Abstract The development of new energetic materials is an emerging area of materials chemistry facilitated by a worldwide need to replace materials used at present, due to environmental considerations and safety requirements, while at the same time securing high performance. The development of such materials is complex, owing to the fact that several different and apparently mutually exclusive material properties have to be met in order for a new material to become widely accepted. In turn, understanding the basic principles of structure property relationships is highly desirable, as such an understanding would allow for a more rational design process to yield the desired properties. This article covers the trinitroethyl functionality and its potential for the design of next generation energetic materials, and describes relevant aspects of energetic materials chemistry including theoretical calculations capable of reliably predicting material properties. The synthesis, characterization, energetic properties, and structure property relationships of several new promising compounds displaying excellent material properties are reported with respect to different kinds of applications and compared to standard explosives currently used. Based on a review of trinitroethyl-containing compounds available in the literature, as well as this new contribution, it is observed that high density can generally be obtained in a more targeted manner in energetic materials taking advantage of noncovalent bonding interactions, a prerequisite for the design of next generation energetic materials. [source]


Profiling the Yorkshire county elector of the early eighteenth century: new material and methods

HISTORICAL RESEARCH, Issue 184 2001
Richard Hall
This article investigates the possibilities for re-examining the political motivations of eighteenth-century county electors in the light of their socio-economic status. It focuses upon the linkage of estate and electoral records for several townships in Yorkshire, with particular attention paid to the deeds registries of Yorkshire as a source for the political historian. Whilst the argument stresses the importance of developing a broader understanding of the voters' motivations, its key conclusion is that the more one knows about individual electors, the less confidence one can have in generalizations based upon aggregate analyses of poll books. [source]


Royal Patronage and the Earls in the Reign of Edward I

HISTORY, Issue 309 2008
ANDREW M. SPENCER
Despite his reputation as one of the most successful English monarchs of the middle ages, Edward I has never been seen as a generous king. This article looks afresh at the accepted view of Edward I as a miserly king and, by examining his relationship with his earls, seeks to demonstrate that Edward had a sophisticated and judicious approach to patronage which was based upon rewarding good service. The article attempts to place Edward I's patronage in line with the later template of Edward III. In reassessing the judgements of K. B. McFarlane and M. C. Prestwich, the article reconsiders Edward's policy of land grants in England, Wales and Scotland, and also draws upon new material such as the king's grants of deer from the royal forests, charters of free warren and the remission of debts to the exchequer. [source]


Bis(carbazolyl)benzodifuran: A High-Mobility Ambipolar Material for Homojunction Organic Light-Emitting Diode Devices

ADVANCED MATERIALS, Issue 37 2009
Hayato Tsuji
A new ambipolar material bis(carbazolyl)benzodifuran (CZBDF) shows well-balanced and high carrier mobilities for both holes and electrons (>10,3,cm2 V,1 s,1). This new material allows us to fabricate efficient p-i-n homojunction OLEDs that emit light across the full visible color range and perform at a level similar to state-of-the-art heterojunction devices. [source]


Diatomaceous Lessons in Nanotechnology and Advanced Materials

ADVANCED MATERIALS, Issue 29 2009
Dusan Losic
Abstract Silicon, in its various forms, finds widespread use in electronic, optical, and structural materials. Research on uses of silicon and silica has been intense for decades, raising the question of how much diversity is left for innovation with this element. Shape variation is particularly well examined. Here, we review the principles revealed by diatom frustules, the porous silica shells of diatoms, microscopic, unicellular algae. The frustules have nanometer-scale detail, and the almost 100,000 species with unique frustule morphologies suggest nuanced structural and optical functions well beyond the current ranges used in advanced materials. The unique frustule morphologies have arisen through tens of millions of years of evolutionary selection, and so are likely to reflect optimized design and function. Performing the structural and optical equivalent of data mining, and understanding and adopting these designs, affords a new paradigm in materials science, an alternative to combinatorial materials synthesis approaches in spurring the development of new material and more nuanced materials. [source]