Home About us Contact
|
Home About us Contact | ||
|
|
||
Embedded
Kinds of Embedded Terms modified by Embedded Selected AbstractsDUNG BY PREFERENCE: THE CHOICE OF FUEL AS AN EXAMPLE OF HOW ANDEAN POTTERY PRODUCTION IS EMBEDDED WITHIN WIDER TECHNICAL, SOCIAL, AND ECONOMIC PRACTICES,ARCHAEOMETRY, Issue 1 2000B. SILLAR A discussion of how Andean potters acquire and use their fuels is used to demonstrate the ,embedded'nature of ceramic technology. The most common choice of fuel in the highlands of Peru and Bolivia is animal dung (mainly cow, sheep, and llama). This technological choice is related to wider social and economic practices (particularly in relation to animal husbandry) which has further repercussions that affect other technologies (such as agriculture practices). Such a succession of interrelated activities is not unique to pottery; it is fundamental to all technologies and should be considered within archaeological analysis. [source] High Antibacterial and Antifungal Activity of Silver Monodispersed Nanoparticles Embedded in a Glassy Matrix,ADVANCED ENGINEERING MATERIALS, Issue 7 2010Leticia Esteban-Tejeda Silver doped glass powders have been obtained starting from vitellinate/nAg and montmorillonite/nAg. These powders have shown a high biocide activity against the three different types of microorganisms studied: Escherichia coli (gram-negative bacteria), Micrococcus luteus (gram-positive-bacteria), and Issatchenkia orientalis (yeast). It was found that these glasses keep constant the silver concentration even below the cytotoxic limit. Therefore we interpret that silver doped glasses play the role of dosing devices. [source] Inkjet-Printed Single-Droplet Organic Transistors Based on Semiconductor Nanowires Embedded in Insulating PolymersADVANCED FUNCTIONAL MATERIALS, Issue 19 2010Jung Ah Lim Fabrication of organic field-effect transistors (OFETs) using a high-throughput printing process has garnered tremendous interest for realizing low-cost and large-area flexible electronic devices. Printing of organic semiconductors for active layer of transistor is one of the most critical steps for achieving this goal. The charge carrier transport behavior in this layer, dictated by the crystalline microstructure and molecular orientations of the organic semiconductor, determines the transistor performance. Here, it is demonstrated that an inkjet-printed single-droplet of a semiconducting/insulating polymer blend holds substantial promise as a means for implementing direct-write fabrication of organic transistors. Control of the solubility of the semiconducting component in a blend solution can yield an inkjet-printed single-droplet blend film characterized by a semiconductor nanowire network embedded in an insulating polymer matrix. The inkjet-printed blend films having this unique structure provide effective pathways for charge carrier transport through semiconductor nanowires, as well as significantly improve the on-off current ratio and the environmental stability of the printed transistors. [source] Enhanced Electrical Switching and Electrochromic Properties of Poly(p-phenylenebenzobisthiazole) Thin Films Embedded with Nano-WO3ADVANCED FUNCTIONAL MATERIALS, Issue 18 2010Jiahua Zhu Abstract The electrical switching and electrochromic phenomena of a novel nanocomposite comprising poly(p-phenylenebenzobisthiazole) (PBZT) and tungsten oxide (WO3) nanoparticles are investigated as a function of the nanoparticle loading. Both dissolving PBZT and doping PBZT backbone structure with acid are achieved by one simple step. Chlorosulfonic acid (CSA) is used as a solvent and spontaneously transformed to sulfuric acid upon exposure to moisture. The formed sulfuric acid serves as doping agent to improve the electrical conductivity of PBZT. The most significant enhancement of electrical switching is observed in the nanocomposites with low weight fraction (5%). The electrical conductivity of 5% WO3/PBZT nanocomposite thin film is increased by about 200 times and 2 times, respectively, as compared to those of the as-received PBZT and PBZT/CSA thin films. As the nanoparticle loading increases to 20% and 30%, the nanocomposites follow an ohmic conduction mechanism. Stable electrical conductivity switching is observed before and after applying a bias on the pristine PBZT and WO3/PBZT nanocomposite thin films. Electrochromic phenomena of both PBZT and WO3/PBZT nanocomposite thin films with high contrast ratio are observed after applying a bias (3 V). The mechanisms of the nanoparticles in enhancing the electrical switching and electrochromic properties are proposed. [source] Microstructures: Facile Fabrication of Monolithic 3D Porous Silica Microstructures and a Microfluidic System Embedded with the Microstructure (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 9 2010Mater. D.-P. Kim and co-workers present the fabrication of monolithic 3D porous silica structures into a multilayer framework with bimodal pore size distribution on page 1473. The structure becomes monolithic upon pyrolyzing the stacked layers, and then easily embedded in microchannel with the aid of photolithography, leading to a microfluidic system with built-in microstructure in a site- and shape-controlled manner. [source] Facile Fabrication of Monolithic 3D Porous Silica Microstructures and a Microfluidic System Embedded with the MicrostructureADVANCED FUNCTIONAL MATERIALS, Issue 9 2010ZuoYi Xiao Abstract Monolithic 3D porous silica structures are fabricated into a multilayer framework with a bimodal pore size distribution in the micrometer and sub-micrometer range. The fabrication , which involves directed assembly of colloidal spheres, transfer printing, and removal of a sacrificial template , yields robust and mechanically stable structures over a large area. The structure becomes monolithic upon pyrolyzing the stacked layers, which induces necking of the particles. The monolithic microstructures can easily be embedded in microchannels with the aid of photolithography, leading to the formation of a microfluidic system with a built-in microstructure in a site- and shape-controlled manner. Utilization of the system results in a fourfold increase in the mixing efficiency in the microchannel. [source] Cover Picture: Fabrication of Stable Metallic Patterns Embedded in Poly(dimethylsiloxane) and Model Applications in Non-Planar Electronic and Lab-on-a-Chip Device Patterning (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 4 2005Mater. Abstract A composite image is shown that highlights examples of device architectures that either incorporate or exploit polymer-embedded metallic microstructures. In work reported by Nuzzo and co-workers on p.,557, new applications of soft lithography, in conjunction with advanced forms of multilayer metallization, are used to construct these exceptionally durable structures. They are suitable for use in non-planar lithographic patterning, and as device components finding applications ranging from microelectronics to Lab-on-a-Chip analytical systems. This article describes the fabrication of durable metallic patterns that are embedded in poly(dimethylsiloxane) (PDMS) and demonstrates their use in several representative applications. The method involves the transfer and subsequent embedding of micrometer-scale gold (and other thin-film material) patterns into PDMS via adhesion chemistries mediated by silane coupling agents. We demonstrate the process as a suitable method for patterning stable functional metallization structures on PDMS, ones with limiting feature sizes less than 5,,m, and their subsequent utilization as structures suitable for use in applications ranging from soft-lithographic patterning, non-planar electronics, and microfluidic (lab-on-a-chip, LOC) analytical systems. We demonstrate specifically that metal patterns embedded in both planar and spherically curved PDMS substrates can be used as compliant contact photomasks for conventional photolithographic processes. The non-planar photomask fabricated with this technique has the same surface shape as the substrate, and thus facilitates the registration of structures in multilevel devices. This quality was specifically tested in a model demonstration in which an array of one hundred metal oxide semiconductor field-effect transistor (MOSFET) devices was fabricated on a spherically curved Si single-crystalline lens. The most significant opportunities for the processes reported here, however, appear to reside in applications in analytical chemistry that exploit devices fabricated using the methods of soft lithography. Toward this end, we demonstrate durably bonded metal patterns on PDMS that are appropriate for use in microfluidic, microanalytical, and microelectromechanical systems. We describe a multilayer metal-electrode fabrication scheme (multilaminate metal,insulator,metal (MIM) structures that substantially enhance performance and stability) and use it to enable the construction of PDMS LOC devices using electrochemical detection. A polymer-based microelectrochemical analytical system, one incorporating an electrode array for cyclic voltammetry and a microfluidic system for the electrophoretic separation of dopamine and catechol with amperometric detection, is demonstrated. [source] LiFePO4 Nanoparticles Embedded in a Nanoporous Carbon Matrix: Superior Cathode Material for Electrochemical Energy-Storage DevicesADVANCED MATERIALS, Issue 25-26 2009Xing-Long Wu An optimized nanostructure design for high-power, high-energy lithium-ion batteries and supercapacitors is realized by fabricating a nanocomposite with highly dispersed nanoparticles of active materials in a nanoporous carbon matrix. A nano-LiFePO4/nanoporous carbon matrix nanocomposite forms a bridge between a supercapacitor and a battery electrode and offers a reasonable compromise between rate and capacity. [source] Six-Month-Olds' Detection of Clauses Embedded in Continuous Speech: Effects of Prosodic Well-FormednessINFANCY, Issue 1 2000Thierry Nazzi Three experiments investigated the role of prosodic structure for infants' recognition of embedded word sequences. Six-month-olds were familiarized with 2 versions of the same sequence, 1 corresponding to a well-formed prosodic unit and the other to a prosodically ill-formed sequence (although a successive word series). Next, infants heard 2 test passages. One included the well-formed unit, and the other included the ill-formed sequence. In Experiment 1, infants listened longer to the passage containing the well-formed unit, suggesting that such units, even when they are embedded, are better recognized. Experiments 2 and 3 showed that this better recognition does not depend on an acoustic match between the familiarized sequences and their later embeddings. This suggests that the advantage of the well-formed unit is at least partially due to infants' use of prosody to parse continuous speech. [source] Organic Thin-film Transistors Based on Polythiophene Nanowires Embedded in Insulating PolymerADVANCED MATERIALS, Issue 13 2009Longzhen Qiu Blending poly(3-hexylthiophene) (P3HT) and amorphous polystyrene (PS) using a marginal solvent (CH2Cl2) with temperature-dependent solubility allows a reduction of the semiconductor content to as low as 3 wt% without considerable degradation of the field-effect electronic properties. Morphological and structural studies reveal that the P3HT molecules in these blends form highly crystalline, interconnected nanofibrillar networks. [source] Nanoscale Writing of Transparent Conducting Oxide Features with a Focused Ion BeamADVANCED MATERIALS, Issue 6 2009Norma E. Sosa Embedded, optically transparent, electrically conducting oxide nanowires, and other patterns are written on highly resistive transparent metal oxide thin films with nanoscale spatial control using focused ion beam implantation. The resulting transparent conducting oxide features are 110-160 nm wide, 7 nm deep, and are theoretically limitless in length, connectivity, and shape. [source] Success factors for the effective implementation of renewable energy options for rural electrification in India,Potentials of the CLEAN DEVELOPMENT MECHANISMINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 12 2008Gudrun Elisabeth Benecke Abstract Developing countries as well as international development assistance have for a long time aspired to combat energy poverty in rural areas of developing countries. However, until now a major part of national and international public and private attempts to provide affordable and stable energy supply have failed due to various economic, political, social and institutional obstacles. This situation is reflected in case of India where in comparison with other South Asian states the status of rural electrification and of energy supply are in a dismal state despite the promotion of renewable energy and rural electrification as early as from the 1960s. Embedded in the global context of the international climate change regime, the Clean Development Mechanism (CDM) of the Kyoto Protocol has now emerged as a new option to facilitate investment in climate change mitigating projects. In this respect, promoting the deployment of renewable energy through this project-based mechanism opens new avenues for rural electrification. The main objective of this paper is, hence, to examine the context conditions and factors determining the effective application of renewable energy options for rural electrification in a developing country context, namely India. Understanding contextual requirements for renewable energy investment has proved imminently important in order to appreciate the potentials provided by new market-based mechanisms such as the CDM for rural poverty alleviation. Comparative political science case study research methods are applied to the analysis of CDM biomass projects in the context of the four Indian states of Tamil Nadu, Maharashtra, Punjab and Andhra Pradesh. This allows for the conclusion that socio-political and historic framework conditions matter for the implementation of new renewable energy options. Copyright © 2008 John Wiley & Sons, Ltd. [source] Membership Matters: On the Value of Being Embedded in Customer NetworksJOURNAL OF MANAGEMENT STUDIES, Issue 6 2010Øystein D. Fjeldstad abstract Learning about customers and their contexts is vital to firm strategy. We examine how firms can learn by participating in their customers' networks. Specifically, we explain how a bank can increase the value that it creates for customers by being embedded in the networks in which the customers are embedded. We argue that knowledge pertinent to a particular customer is available in the network of affiliated, inter-related customers, and that being structurally embedded in this network can help banks overcome information asymmetries. We use hierarchical linear modelling to test the argument that a bank's structural embeddedness in its customers' network positively affects the bank's ability to offer favourable credit terms. We find that not only does such structural embeddedness affect credit terms, but it also moderates the effects of previously examined relational embeddedness on credit terms. [source] Synthesis of Nanotube Array Composed of an Amorphous Matrix Embedded with NaCl-Type SiC Crystallites by Chemical Vapor Infiltration TechniquesJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 6 2010Wen Yang Highly dense oriented arrays of nanotubes were synthesized via a chemical vapor infiltration process using anodic alumina membrane as a template. The nanotubes have a unique granular structure, which is composed of SiC nanocrystals embedded in an amorphous matrix. X-ray diffraction and high-resolution transmission electron microscopy examinations both indicate an NaCl-type crystalline structure of the SiC nanocrystals in the nanotubes. The process described here can be extended to the preparation of other nanomaterials that are suitable to be obtained via a vapor,solid approach. [source] Crystallographic Orientation of Y2Ba4CuMOx (M=Nb, Zr, Ag) Nanoparticles Embedded in Bulk, Melt-Textured YBCO Studied by EBSDJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 8 2007A. Koblischka-Veneva Crystallographic orientations of Y,Ba,Cu,O (YBCO) and embedded Y2Ba4CuMOx (M=Nb, Zr, Ag) nanoparticles in bulk, melt-textured YBCO samples are studied by electron backscatter diffraction. Y2BaCuO5 particles exhibit no preferred orientation but have a strong negative influence on the matrix orientation. In contrast, the nanoparticles do not disturb the texture of the YBCO matrix. Depending on the preparation route, a different particle orientation with respect to the matrix is obtained. Untextured nanoparticles are formed by solid-state reaction during the melt process by adding oxides (Nb2O5 or Y2O3) to the precursor powder. Preformed Y2Ba4CuMOx particles added to the precursor in the form of prereacted nanopowder exhibit a dominant single orientation related to the surrounding YBCO matrix. [source] The unwary purchaser: Consumer psychology and the regulation of commerce in AmericaJOURNAL OF THE HISTORY OF THE BEHAVIORAL SCIENCES, Issue 4 2007Michael J. Pettit Starting in the 1870s, American jurists deciding cases of trademark infringement began advancing arguments that the ordinary purchaser was an unwary one, easily deceived by imitations. Embedded within their legal decisions was a vision of the typical consumers' habitual behavior and cognitive ability. In response to legal critics who argued that the presumed psychology of the consumer was unevenly deployed, applied psychologists developed laboratory-based experiments and scales for determining the likelihood that the "average" purchaser would be confused. Although these psychologists failed in their goal of securing regular legal patronage, this commercial context and the resulting experiments were constitutive of the delineation of "recognition" as a distinct mental process. Furthermore, this case study complicates the scholarly consensus about the role of standardization and personal responsibility in the liberal administration of mass society. © 2007 Wiley Periodicals, Inc. [source] Sweet nationalism in bitter days: a commercial representation of ZionismNATIONS AND NATIONALISM, Issue 3 2009ANAT FIRST ABSTRACT. This article identifies several theoretical approaches to the role of culture in the construction of national identity. Embedded in the presently emerging approach, which emphasises the relations between popular culture/consumerism and national identity, this study focuses on a specific consumer good manufactured in Israel in the early 2000s, the height of the second Palestinian Intifada (uprising): small sugar packets bearing portraits of the patriarchs of Zionism. The analysis of this product, employing semiotic analysis, interviews and focus groups, locates it in the five ,moments' of du Gay's ,circuit of culture' (i.e. identity, representation, production, consumption and regulation). Three main general arguments were stated, empirically examined and largely sustained: (1) Consumer goods are used not only for constructing national identity but also as a means for ,healing' it; (2) in their ,healing' capacity, representations of nationalism on consumer goods do not add new elements to representations offered by the ,high' official version of nationalism but replicate them in a simplified way; (3) while trivialising the insights and concepts that originated in ,high' culture, consumer goods expose the prejudices, stereotypes and rules of inclusion and exclusion that in ,high' culture are often hidden in a sophisticated manner. [source] Determination of Size Distributions of Concentrated Polymer Particles Embedded in a Solid Polymer MatrixPARTICLE & PARTICLE SYSTEMS CHARACTERIZATION, Issue 1 2008Ezequiel R. Soulé Abstract In this work we present the results obtained from the size characterization of polymer particles embedded in a solid polymer matrix using Static Light Scattering (SLS) and Scanning Electron Microscopy (SEM). The analyzed samples are the result of the solution polymerization of isobornyl methacrylate (IBoMA) in polyisobutylene (PIB) at complete conversion. Induced by polymerization, the system undergoes phase separation. As a result, spherical micron sized particles rich in PIB are formed. At the end of the polymerization, the particles become trapped in a solid polymer matrix rich in Poly-IBoMA. Size, concentration, and refractive index, make the resulting particle system scatter light under the Rayleigh-Debye-Gans (RDG) regime with interparticle interference. For Light Scattering (LS) characterization the samples are measured with a Flat Cell Static Light Scattering (FCSLS) apparatus, in which the reaction takes place. The resulting SLS spectra are analyzed using the Percus-Yevick approximation to model the interference effects. The local monodisperse approximation is used to consider polydispersity in the particle sizes. The estimated particle size distributions agree well with the measurements from SEM. In this work a concentrated particle system that naturally scatters light according to the RDG regime has been fully characterized in terms of its particle size distribution. This work, against the opinion of other authors, shows the feasibility of measuring still particles using a one dimensional array of light detectors. [source] Positioning the learning asset portfolio as a key component in an organization's enterprise risk management strategyPERFORMANCE IMPROVEMENT, Issue 6 2009Peter J. McAliney This article presents a process for valuing a portfolio of learning assets used by line executives across industries to value traditional business assets. Embedded within the context of enterprise risk management, this strategic asset allocation process is presented step by step, providing readers the operational considerations to implement this program within their organization to enhance performance improvement. At the individual initiative level, readers will recognize elements used in developing retrospective return on investments (ROIs) for learning programs. [source] Mechanism of Motivated Reasoning?AMERICAN JOURNAL OF POLITICAL SCIENCE, Issue 4 2007Analogical Perception in Discrimination Disputes This article examines the boundaries of motivated reasoning in legal decision making. We propose a model of attitudinal influence involving analogical perception. Attitudes influence judgments by affecting the perceived similarity between a target case and cases cited as precedent. Bias should be most apparent in judging similarity when cases are moderately similar on objective dimensions. We conducted two experiments: the first with undergraduates, the second with undergraduates and law students. Participants in each experiment read a mock newspaper article that described a "target case" involving unlawful discrimination. Embedded in the article was a description of a "source case" cited as legal precedent. Participants in both studies were more likely to find source cases with outcomes that supported their policy views in the target dispute as analogous to that litigation. Commensurate with our theory, there was evidence in both experiments that motivated perceptions were most apparent where cases were moderately similar on objective dimensions. Although there were differences in the way lay and law student participants viewed cases, legal training did not appear to attenuate motivated perceptions. [source] Freud's prehistoric matrix-Owing ,nature' a deathTHE INTERNATIONAL JOURNAL OF PSYCHOANALYSIS, Issue 6 2007Joan Raphael-Leff This paper is informed by contemporary literature in two fields-neonatal research, on the one hand, and the burgeoning interdisciplinary interest in Moses and monotheism, on the other. The author postulates that a cluster of traumatic events during the first two years of Freud's life compelled him to repeat what could not be remembered. Embedded in charged implicit schema, these affects remained unprocessed in Freud, who alone of all psychoanalysts did not have an analysis, manifesting in an uncanny dread/allure of the ,prehistoric' as a dark and dangerous era relating to the archaic feminine/maternal matrix and fratricidal murderousness. Furthermore, she cites evidence to suggest that for Freud this unconsciously excluded subtext of the preoedipal era became associated with ancient Egyptian and Minoan-Mycenaean cultures, a passionate fascination actualized in his collection of antiquities yet incongruously absent in his theoretical work, with three exceptions-Egyptian allusions in Leonardo's unconscious attachment to his archaic mother; the ,Minoan-Mycenaean' analogy on discovering the pre-oedipal mother shortly after the death of Freud's own mother; and Egypt as cradle of humanity in his uncharacteristically rambling, troubled text of Moses and monotheism. The author sees Freud's conceptual avoidance yet compulsive reworking of the prehistoric matrix as a symptomatic attempt to expose early unformulated representations that ,return to exert a powerful effect.' [source] Managing platform architectures and manufacturing processes for nonassembled productsTHE JOURNAL OF PRODUCT INNOVATION MANAGEMENT, Issue 4 2002Marc H. Meyer The article presents methods for defining product platforms and measuring business performance in process intensive industries. We first show how process intensive product platforms can be defined using the products and processes of a film manufacturer. We then present an empirical method for understanding the dynamics of process intensive platform innovation, allocating engineering and sales data to specific platform and product development efforts within a product family. We applied this method to a major product line of a materials manufacturer. We gathered ten years of engineering and manufacturing cost data and allocated these to successive platforms and products, and then generated R&D performance measures. These data show the dynamic of heavy capital spending relative to product engineering as one might expect in a process intensive industries. The data also show how derivative products can be leveraged from underlying product platforms and processes for nonassembled products. Embedded within these data are strategies for creating reusable subsystems (comprising components, materials, etc.) and common production processes. Hard data on the degree to which subsystems and processes are shared across different products frequently are typically not maintained by corporations for the duration needed to understand the dynamics of evolving product families. For this reason, we developed and applied a second method to assess the degree of reuse of subsystems and processes. This method asks engineering managers to provide subjective ratings on an ordinal scale regarding the use of technology and processes from one product to the next in a cumulative manner. We find that high levels of reuse generally indicate that a product family was developed with a platform discipline. We applied this measure of platform intensity to two product lines of integrated circuits from another large manufacturer. We used this method to gather approximately ten years of information for each product family. Upon analysis, one product family showed substantial platform discipline, emphasizing a common architecture and processes across specific products within the product line. The other product family was developed with significantly less sharing and reuse of architecture, components, and processes. We then found that the platform centric product family outperformed the latter along a number of performance dimensions over the course of the decade under examination. [source] Gold Nanoparticles Embedded in a Mesoporous Carbon Nitride Stabilizer for Highly Efficient Three-Component Coupling Reaction,ANGEWANDTE CHEMIE, Issue 34 2010Träger mit Dreifachfunktion: Au-Nanopartikel mit Größen unter 7,nm wurden in den Kanälen eines mesoporösen Kohlenstoffnitrid(MCN)-Trägers hergestellt, der als Stabilisator, zur Größenkontrolle und als Reduktionsmittel fungiert (siehe Bild; Au-NPs grün). Die eingebetteten, gut dispergierten Au-Nanopartikel sind hoch aktive, selektive und wiederverwendbare Katalysatoren in der Dreikomponentenkupplung von Benzaldehyd, Piperidin und Phenylacetylen zur Synthese von Propargylamin. [source] A Porphyrin-Related Macrocycle with an Embedded 1,10-Phenanthroline Moiety: Fluorescent Magnesium(II) Ion Sensor,ANGEWANDTE CHEMIE, Issue 1 2010Masatoshi Ishida Exklusiver Gast: Ein neuartiger, porphyrinähnlicher Makrocyclus konnte durch den Austausch der Dipyrromethen- gegen eine 1,10-Phenanthrolin-Einheit erhalten werden. Dieser Makrocyclus ermöglicht die hochselektive Komplexierung und Fluoreszenzdetektion von Mg2+ in Gegenwart anderer physiologisch relevanter Metallionen wie Na+, K+ und Ca2+ und eignet sich gut als Fluoreszenzsensor für Mg2+, selbst in HEPES-gepufferter H2O/DMSO-Lösung (pH,7.4). [source] Nanoscience for Art Conservation: Oil-in-Water Microemulsions Embedded in a Polymeric Network for the Cleaning of Works of Art,ANGEWANDTE CHEMIE, Issue 47 2009Emiliano Carretti Dr. So gut wie neu: Öl-in-Wasser-Nanobehälter in einem wässrigen Polymernetzwerk ermöglichten ein effektives, weitgehend zerstörungsfreies und selektives Reinigen von bemalten und vergoldeten Oberflächen. Wechselwirkungen mit dem Polymer (im Bild schwarz) veränderten die Struktur der Mikroemulsions-Nanotröpfchen (hellblau und rot) kaum. Ein Foto einer Gleichgewichtsmischung aus Mikroemulsion und Polymer ist ebenfalls gezeigt. [source] Titanosilsesquioxanes Embedded in Synthetic Clay as a Hybrid Material for Polymer Science,ANGEWANDTE CHEMIE, Issue 33 2009Fabio Carniato Dr. Zwischen den Schichten: Ein neuartiges Hybridmaterial (siehe Bild) wurde durch die Interkalation eines difunktionellen Titanosilsesquioxans in synthetisches Natriumsaponit erhalten. Ein Nanokomposit aus einer Polystyrolmatrix und dem Hybrid als Additiv weist verbesserte thermooxidative Eigenschaften auf. [source] Managing precipitation use in sustainable dryland agroecosystemsANNALS OF APPLIED BIOLOGY, Issue 2 2004GARY A PETERSON Summary In the Great Plains of North America potential evaporation exceeds precipitation during most months of the year. About 75% of the annual precipitation is received from April through September, and is accompanied by high temperatures and low relative humidity. Dryland agriculture in the Great Plains has depended on wheat production in a wheat-fallow agroecosystem (one crop year followed by a fallow year). Historically this system has used mechanical weed control practices during the fallow period, which leaves essentially no crop residue cover for protection against soil erosion and greatly accelerates soil organic carbon oxidation. This paper reviews the progress made in precipitation management in the North American Great Plains and synthesises data from an existing long-term experiment to demonstrate the management principles involved. The long-term experiment was established in 1985 to identify dryland crop and soil management systems that would maximize precipitation use efficiency (maximization of biomass production per unit of precipitation received), improve soil productivity, and increase economic return to the farmers in the West Central portion of the Great Plains. Embedded within the primary objective are sub-objectives that focus on reducing the amount of summer fallow time and reversing the soil degradation that has occurred in the wheat-fallow cropping system. The experiment consists of four variables: 1) Climate regime; 2) Soils; 3) Management systems; and 4) Time. The climate variable is based on three levels of potential evapotranspiration (ET), which are represented by three sites in eastern Colorado. All sites have annual long-term precipitation averages of approximately 400,450 mm, but vary in growing season open pan evaporation from 1600 mm in the north to 1975 mm in the south. The soil variable is represented by a catenary sequence of soils at each site. Management systems, the third variable, differ in the amount of summer fallow time and emphasize increased crop diversity. All systems are managed with no-till techniques. The fourth variable is time, and the results presented in this paper are for the first 12 yr (3 cycles of the 4-yr system). Comparing yields of cropping systems that differ in cycle length and systems that contain fallow periods, when no crop is produced, is done with a technique called "annualisation". Yields are "annualised" by summing yields for all crops in the system and dividing by the total number of years in the system cycle. For example in a wheat-fallow system the wheat yield is divided by two because it takes 2 yr to produce one crop. Cropping system intensification increased annualised grain and crop residue yields by 75 to 100% compared to wheat-fallow. Net return to farmers increased by 25% to 45% compared to wheat-fallow. Intensified cropping systems increased soil organic C content by 875 and 1400 kg ha,1, respectively, after 12 yr compared to the wheat-fallow system. All cropping system effects were independent of climate and soil gradients, meaning that the potential for C sequestration exists in all combinations of climates and soils. Soil C gains were directly correlated to the amount of crop residue C returned to the soil. Improved macroaggregation was also associated with increases in the C content of the aggregates. Soil bulk density was reduced by 0.01g cm,3 for each 1000 kg ha,1 of residue addition over the 12-yr period, and each 1000 kg ha,1 of residue addition increased effective porosity by 0.3%. No-till practices have made it possible to increase cropping intensification beyond the traditional wheat-fallow system and in turn water-use efficiency has increased by 30% in West Central Great Plains agroecosystems. Cropping intensification has also provided positive feedbacks to soil productivity via the increased amounts of crop residue being returned to the soil. [source] Platinum Nanoelectrodes Embedded in an Insulating Alumina Matrix: An Innovative Approach,CHEMICAL VAPOR DEPOSITION, Issue 4 2005A. Battiston A novel strategy, based on MOCVD, has been employed for preparation of ensembles of platinum nanoelectrodes. Pt/Al2O3 films with different Pt loading were deposited in just one step on glass capillaries. Nanocomposite films with varying Pt/Al atomic ratios were investigated by both cyclic voltammetry and TEM. Ensembles of nanoelectrodes with either overlap or no overlap of the diffusion layers of each nanoelectrode are obtained, depending on the Pt loading. From TEM measurements average Pt particle size of 3 , 7 nm was determined (Figure). [source] ChemInform Abstract: A One-Dimensional Metal Embedded in Salt Matrices: Synthesis, Modulated Crystal Structures, Electrical Conductivity, and Chemical Bonding of ,1[PdBi6] [(Bi,Sn)1-,Br5- ,,].CHEMINFORM, Issue 52 2009Bernhard Wahl 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] ChemInform Abstract: Magnetic Excitations in Cu6 and Mn6 Hexagons Embedded in D3d -Symmetric Polyoxotungstates.CHEMINFORM, Issue 1 2008Noa Zamstein 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] | |||||||||||||||||||||||||||||||||||||||||||