Geophysical studies have resulted in remarkable advances in characterization of critical zone. The geophysics applications uncover the relationships between structure and function in subsurface as they seek to define subsurface structural units with individual properties of retention and trans...

The aim of this thesis was to investigate the process-structure-property relationships of UV-curable hyperbranched polymer (HBP)/silica nanocomposites. Special attention was paid to the interplay between photo-conversion, rheological behavior, shrinkage, and stress dynamics. ...

The overall objective of this study was to elucidate the processing structure property relationship associated with the heat-affected zone (HAZ) produced in an HSLA microalloyed steel during arc welding. Single pass submerged arc welds on a Nb-V microallo...

Ir the hot-pressed samples that exhibited the lines the carbonaceous material is ... Structure-property relationships based on Raman spectroscopy will aid ... necessary to put the results on a firm quantitative foundation are currently underway.

The layers' structure, interlayer boundaries and magnetic properties of Co/CoO films sputtered on single-crystal MgO(100) and Al2O3(110) substrates have been investigated. The relationship between the structure and magnetic properties is analyzed. The NGR investigations of 57Co atomic probes on the Co film surface and Co/CoO interface have been carried out.

This work challenges the popular view that silk has exceptional intrinsic mechanical properties of strength and toughness. All polymer fibres are shown to follow one fracture mechanics relationship between failure strength and the ratio of elastic modulus to fibre diameter. Predictive structure-property relations are derived for strength and fracture toughness, and small diameter plays a large part in silk properties. PMID:23180482

Glycation, otherwise known as Maillard reaction, endows food proteins with improved functional properties, such as solubility, water retention capacity, gelling capacity, and emulsifying properties, and it occurs under mild and safe conditions and requires no extraneous chemicals. These make the glycation a promising method for protein modification in food industry. Recent years have seen an increasing interest in physicochemical properties and structure of glycoconjugates, for a better understanding of the relationship between the structure and functional properties. Thus exploring the systematic research methods and information of physicochemical properties and structure will be very helpful. The aim of the present review is to summarize the state-of-the-art about research methods and re...

Research on novel high-pressure superhard materials (those approaching diamond and cubic boron nitride in hardness) is driven by both scientific and practical objectives: the desire to understand their structure and bonding, which determine the unique properties of these materials, on one hand, and the demand of modern technologies for robust materials with superior properties, on the other. Structure-property relationships in newly synthesised superhard materials, as well as some methodological aspects of their characterisation are in focus of the present paper.

Adsorbent properties of modified coals were studied using frontal chromatography technique. The relationship between modifications of the associated structure of coals resulting from chemical treatments (alkylation, oxidation) and the adsorption properties was established. The adsorption and desorption isotherms of aqueous phenol solutions on coals shown that alkylated coals have interesting adsorbent properties. These properties are descreased by oxidation, due to the secondary cross linking reactions. (orig.)

Research on the structure and function relationships of lupin meal or lupin native protein is limited. The scope of this work is to study lupin's native proteins' thermal and rheological properties in whole meal. The effect of pH and heat treatment on the thermal properties of lupin meal was studi...

Magnetic thin films and nanostructure exhibit novel properties and have great technological potential. In particular, developing thin film structures with perpendicular anisotropy, understanding the underlying mechanisms and identifying meaningful microstructure-property relationships in such nanometer scale materials is an ongoing challenge. Here, two different approaches as well as details of the relevant microstructure are presented. 6 refs, 2 figs.

An investigation has been made to improve the impact properties of a dual phase Fe/1.5Mn/.06C steel for potential low temperature application. The research involved establishing the microstructure-property relationships, especially with regard to the morphology of the constituents. Dual phase processing was done in two ways, viz., controlled rolling and intercritical annealing of the as-hot-rolled structure.

Conducting polymers hold significant promise as electrode coatings; however, they are characterized by inherently poor mechanical properties. Blending or producing layered conducting polymers with other polymer forms, such as hydrogels, has been proposed as an approach to improving these properties. There are many challenges to producing hybrid polymers incorporating conducting polymers and hydrogels, including the fabrication of structures based on two such dissimilar materials and evaluation of the properties of the resulting structures. Although both fabrication and evaluation of structure-property relationships remain challenges, materials comprised of conducting polymers and hydrogels are promising for the next generation of bioactive electrode coatings. (topical review)

In silico methods characterizing molecular compounds with respect to pharmacologically relevant properties can accelerate the identification of new drugs and reduce their development costs. Quantitative structure???activity/-property relationship (QSAR/QSPR) correlate structure and physico-chemical properties of molecular compounds with a specific functional activity/property under study. Typically a large number of molecular features are generated for the compounds. In many cases the number of generated features exceeds the number of molecular compounds with known property values that are available for learning. Machine learning methods tend to overfit the training data in such situations, i.e. the method adjusts to very specific features of the training data, which are not characteristic...

Our explorations of rare-earth, transition metal intermetallics have resulted in the synthesis and characterization, and electronic structure investigation, as well as understanding the structure-bonding-property relationships. Our work has presented the following results: (1) Understanding the relationship between compositions and properties in LaFe{sub 13-x}Si{sub x} system: A detailed structural and theoretical investigation provided the understanding of the role of a third element on stabilizing the structure and controlling the transformation of cubic NaZn{sub 13}-type structures to the tetragonal derivative, as well as the relationship between the structures and properties. (2) Synthesis of new ternary rare-earth iron silicides RE{sub 2-x}Fe{sub 4}Si{sub 14-y} and proposed superstructure: This compound offers complex structural challenges such as fractional occupancies and their ordering in superstructure. (3) Electronic structure calculation of FeSi{sub 2}: This shows that the metal-semiconductor phase transition depends on the structure. The mechanism of band gap opening is described in terms of bonding and structural distortion. This result shows that the electronic structure calculations are an essential tool for understanding the relationship between structure and chemical bonding in these compounds. (4) Synthesis of new ternary rare-earth Zinc aluminides Tb{sub 3}Zn{sub 3.6}Al{sub 7.4}: Partially ordered structure of Tb{sub 3}Zn{sub 3.6}Al{sub 7.4} compound provides new insights into the formation, composition and structure of rare-earth transition-metal intermetallics. Electronic structure calculations attribute the observed composition to optimizing metal-metal bonding in the electronegative (Zn, Al) framework, while the specific ordering is strongly influenced by specific orbital interactions. (5) Synthesis of new structure type of Zn{sub 39}(Cr{sub x}Al{sub 1-x}){sub 81}: These layered structures are similar to icosahedral Mn-Al quasicrystalline compounds. Therefore, this compound may provide new insights into the formation, composition and structure of quasicrystalline materials.

The layers' structure, interlayer boundaries and magnetic properties of Co/CoO films sputtered on single-crystal MgO(1 0 0) and Al{sub 2}O{sub 3}(1 1 0) substrates have been investigated. The relationship between the structure and magnetic properties is analyzed. The NGR investigations of {sup 57}Co atomic probes on the Co film surface and Co/CoO interface have been carried out.

The composition and structure of an ablative polymer has a multifaceted influence on its thermal, mechanical and ablative properties. Understanding the molecular level information is critical to the optimization of material performance because it helps to establish correlations with the macroscopic properties of the material, the so-called structure-property relationship. Moreover, accurate information of molecular structures is also essential to predict the thermal decomposition pathways as well as to identify decomposition species that are fundamentally important to modeling work. In this presentation, I will describe the use of infrared transmission spectroscopy (FT-IR) as a convenient tool to aid the discovery and development of thermal protection system materials.

Growing evidence indicates that the individualized and highly reproducible N-glycan repertoires on each protein glycosylation site modulate function. Relationships between protein structures and the resulting N-glycoforms have previously been observed, but remain to be quantitatively confirmed and examined in detail to define the responsible mechanisms in the conserved mammalian glycosylation machinery. Here, we investigate this relationship by manually extracting and analyzing quantitative and qualitative site-specific glycoprofiling data from 117 research papers. Specifically, N-glycan structural motifs were correlated with the structure of the protein carriers, focusing on the solvent accessibility of the individual glycosylation sites and the physicochemical properties of the surroundi...

The quantitative structure-property relationship (QSPR) method was used to correlate and predict the infinite-dilution activity coefficients ?i? of organic solutes in three ionic liquids (ILs). The correlated and predicted results from QSPR models agreed well with the experimental ?i? values.   

This books presents current information on commercial development and uses of high temperature superconductors. The common theme is the chemistry of these materials. Topics covered include theory, materials preparation and characterization, structure-property relationships, surfaces and interfaces, processing and fabrication, applications, and research.

is the case one might suspect a relationship between the water-induced porosity and the ...... Ries H. E.. Jr. (1952) Structure and sintering properties of cracking catalysts and related materials. Ad- ... n g a h\\ v~crmis \\r hic h c\\ten(ls over I he ...

Four D-?-A sensitizers comprising a thienyl-diketopyrrolopyrrole (ThDPP) bridge were synthesized and tested in iodide/triiodide liquid electrolyte DSC devices. The dye series was strategically designed to develop a structure-property relationship. The best performing sensitizer utilized a phenyl-based anchor and triphenylamine donor (? = 5.03%). PMID:23019568

In the past three years, we have carried out a number of studies on the deformation and superplasticity of fine-structured materials. The goal was to develop an understanding on the deformation microstructure relationship in these advanced materials and to improve further their properties through microstructural control. In this report, we describe only some of the key results and observations from these studies.

The structure-mechanical properties relationship of dental enamel (made of apatite fibers and a small amount of organics and water) was studied. Enamel?s elastic moduli, elastic/inelastic transition were quantified and the toughening mechanisms were identified for different hierarchical levels. Duri...

Key types of natural and artificial light-harvesting antennas, i.e., supramolecular complexes that absorb light energy and transmit it to the receiver for electronic excitation, are considered. Attention is focused on the architecture of these complexes, the principles of the connection of individual units to a common system and structure-property relationships.The bibliography includes 122 references.

Linking durability of carbon blacks, expressed as their oxidation resistance, used in PEMFCs as catalyst supports, with their chemistry and morphology is an important task towards designing carbon blacks with desired properties. Structure-to-property relationship between surface chemistry determined by X-ray photoelectron spectroscopy (XPS), morphological structure determined by digital image processing of scanning electron microscopy (SEM) images, physical properties, and electrochemical corrosion behavior determined in an air-breathing gas-diffusion electrode is studied for several un-altered and several modified carbon blacks. We are showing that surface chemistry, graphitic content and certain physical characteristics such as Brunauer-Emmett-Teller (BET) surface area and pore volume, d...

Mining and civil engineering projects in the past have frequently required systems to manage the hydrological consequences of their construction, such as water leakage and inflow prevention. This paper addresses the basic relationships which define structure formation kinetics in stabilized clay sealants, and their dependence upon clay mineralogy. In addition, the integrity of stabilized clay sealant properties against chemical aggression and temperature are examined. Finally, the principal used in formulating stabilized clay sealant hydrological, geotechnical and chemical properties are presented. 6 figs.

The ring-opening polymerization of strained, ring-tilted metallocenophanes represents a new and versatile route to high molecular weight poly(ferrocenylsilanes). In this presentation the properties of poly(ferrocenylsilanes) will be described together with the relationships between the monomer structure, strain energy, and polymerization behavior. In addition, the extension of the ring opening route to the preparation of poly(ferrocenylgermanes) and poly(ferrocenylphosphines) will be outlined and the unusual properties of the polymers will be discussed.

Though it is widely appreciated that complex structural, functional and morphological relationships exist between distinct areas of the human cerebral cortex, the extent to which such relationships coincide remains insufficiently appreciated. Here we determine the extent to which correlations between brain regions are modulated by either structural, connectomic or network-theoretic properties using a structural neuroimaging data set of magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) volumes acquired from N=110 healthy human adults. To identify the linear relationships between all available pairs of regions, we use canonical correlation analysis to test whether a statistically significant correlation exists between each pair of cortical parcels as quantified via structural, connectomic or network-theoretic measures. In addition to this, we investigate (1) how each group of canonical variables (whether structural, connectomic or network-theoretic) contributes to the overall correlation and, additionally, (2) whether each individual variable makes a significant contribution to the test of the omnibus null hypothesis according to which no correlation between regions exists across subjects. We find that, although region-to-region correlations are extensively modulated by structural and connectomic measures, there are appreciable differences in how these two groups of measures drive inter-regional correlation patterns. Additionally, our results indicate that the network-theoretic properties of the cortex are strong modulators of region-to-region covariance. Our findings are useful for understanding the structural and connectomic relationship between various parts of the brain, and can inform theoretical and computational models of cortical information processing. PMID:23116816

The role of the crystalline polarity of zinc oxide (ZnO) in the interfacial properties was investigated with semiconductor–insulator–semiconductor structures prepared from ZnO single crystals and an oxide glass insulator. The insulator/ZnO(0001) interface showed highly nonlinear current–voltage (I–V) relationships, characteristic of ZnO varistors, with clear breakdown behavior at a bias voltage of 3 V. Whereas, the insulator/ZnO(000\\\\bar1) interface was characterized by a relatively large leakage current in the pre-breakdown region and very slow decay behavior in the I–V relationships. The dielectric properties of the insulator/ZnO interface also exhibited crystalline polarity dependence.   

The chemical reactivity of epoxides is an important determinant for their toxic effects. The issue of modeling the chemical reactivity toward the nucleophile 4-nitrobenzylpyridine (NBP) of a series of 15 epoxides is addressed. For this purpose a multivariate characterization of their chemical and structural properties is carried out using quantum chemical molecular orbital calculations. By means of partial least-squares projections to latent structures (PLS), a set of nine theoretical descriptors is found to be sufficiently informative form of design the reactivity with NBP. Two calculated quantitative structure-property relationships (QSPRs) are also shown to exhibit sound predictive capabilities.

A survey was conducted of available long-term strength properties of fiberglass-reinforced plastic structures. Included are fluid containment vessels, marine structures, and aircraft components with up to 19 years of service. Correlations were obtained for the variation of static fatigue strength, cyclic fatigue strength, and residual burst strength for pressure vessels. In addition, data were presented for the effects of moisture on strength retention. Data variations were analyzed, and relationships and implications for testing were discussed. Change in strength properties for complete structures was examined for indications of the effects of environmental conditions such as moisture and outdoor exposure (ultraviolet radiation, weathering) on long-term durability.

Electrical and thermal transport properties of quasicrystals are reviewed on the examples of i-Ag-In-Yb and i-Al-Cu-Fe icosahedral phases and d-Al-Co-Ni decagonal phase. Using samples of single-grain morphology and high structural quality, and performing the measurements along well-defined crystallographic directions, the following basic questions in the context of physical properties of quasicrystals are addressed, both experimentally and theoretically: (1) are the unusual transport properties of quasicrystals introduced by the quasiperiodicity of the structure or are they a consequence of complex local atomic order with no direct relationship to the quasiperiodicity; (2) what is the role of the electronic structure of quasicrystals in their electronic transport properties, especially the pseudogap in the electronic density of states in the vicinity of the Fermi energy; (3) what is the anisotropy of the transport coefficients along different crystallographic directions for icosahedral and decagonal quasicrystals and (4) what are the true intrinsic properties of quasicrystalline phases? PMID:22576452

The relationship between the ice polycrystalline structure and the dielectric properties of a frozen gelatin gel were investigated. The Micro-Slicer Image Processing System (MSIPS) was applied to measure the diameter, the perimeter density and the number density of ice crystals. The dielectric property of frozen gelatin gel at various freezing rate was measured in the frequency range of 100Hz to 100kHz at -40°C. The characteristic value of dielectric property, ?0 and ?0-?? have good correlation with structural parameters of ice crystals, such as diameter, perimeter density and number density, while other characteristic value, the relaxation time, ? has no relation to the structure of ice polycrystalline. The resu1ts showed that the possibility of non-destructive measurement of ice structure by dielectric property.

In classical rough set theory, objects are partitioned into equivalence classes based on their attribute values, which essentially represent the functional information associated with the objects. Therefore, rough set theory can be viewed as a theory of functional granulation. In contrast, relational information systems (RISs) specify the relationships between objects, instead of their properties. This study presents a rough set analysis of relational structures, which are more general than functional information systems (FISs) and RISs. Unlike classical rough set theory, in which the attribute values of objects fully determine the indiscernibility relation, the rough set analysis of relational structures must account for the relationships between objects. This study considers three import...

The authors conduct a comprehensive review of nuclear reaction, tracer, radiochemical, and structural analytical techniques for assessing properties such as doping levels and effects, corrosion behavior and resistance, fuel-coolant and coolant-structure relationships, and physical radiation effects on a wide variety of candidate metals and alloys for nuclear and thermonuclear reactor materials. An extensive range of nuclear reactions for determining the diffusion and distribution of dopants and gas impurities is covered.

Aiming at understanding the structural and physical chemical basis of the biological activity of chemicals, the science of structure-activity relationships has seen dramatic progress in the last decades. Coarse-grain, qualitative approaches (e.g., the structural alerts), and fine-tuned quantitative structure-activity relationship models have been developed and used to predict the toxicological properties of untested chemicals. More recently, a number of approaches and concepts have been developed as support to, and corollary of, the structure-activity methods. These approaches (e.g., chemical relational databases, expert systems, software tools for manipulating the chemical information) have dramatically expanded the reach of the structure-activity work; at present, they are powerful and inescapable tools for computer chemists, toxicologists, and regulators. This chapter, after a general overview of traditional and well-known approaches, gives a detailed presentation of the latter more recent support tools freely available in the public domain. PMID:23086838

Civil and military structures, such as helicopters, aircrafts, naval ships, tanks or buildings are susceptible to blast loads as terroristic attacks increases, therefore there is the need to design blast resistant structures. During an explosion the peak pressure produced by shock wave is much greater than the static collapse pressure. Metallic structures usually undergo large plastic deformations absorbing blast energy before reaching equilibrium. Due to their high specific properties, fibre-reinforced polymers are being considered for energy absorption applications in blast resistant armours. A deep insight into the relationship between explosion loads, composite architecture and deformation/fracture behaviour will offer the possibility to design structures with significantly enhanced en...

This grant supported the exploratory synthesis of new actinide materials with all of the actinides from thorium to californium with the exceptions of protactinium and berkelium. We developed detailed structure-property relationships that allowed for the identification of novel materials with selective ion-exchange, selective oxidation, and long-range magnetic ordering. We found novel bonding motifs and identified periodic trends across the actinide series. We identified structural building units that would lead to desired structural features and novel topologies. We also characterized many different spectroscopic trends across the actinide series. The grant support the preparation of approximately 1200 new compounds all of which were structurally characterized.

The physical properties of superlattices are strongly affected by the chemical and physical properties of the individual layers and by the superlattice structure. In this paper the relationship between structure and properties will be illustrated by the giant magnetoresistance (GMR) effect, as well as the dimensional transitions and pinning mechanisms in respectively magnetic and superconducting superlattices. In the first example we will analyse the effect of the sample structure and interface quality on the GMR of polycrystalline and epitaxial Fe/Cr superlattices grown by molecular beam epitaxy. Secondly, the effect of thermal annealing and ion irradiation on the electrical and magnetic properties of Ag/Fe multilayers is discussed. In a third example, the influence of a very thin Fe interlayer on the coupling phenomena in Fe/Nb multilayers is analysed. Finally, it will be shown that an additional lateral modulation (lattice of submicron holes) in Pb/Ge multilayers substantially changes the critical superconducting parameters. (orig.)

The macroscopic properties of many materials are controlled by the structure and chemistry at grain boundaries. A basic understanding of the structure-property relationship requires a technique which probes both composition and chemical bonding on an atomic scale. The high-resolution Z-contrast imaging technique in the scanning transmission electron microscope (STEM) forms an incoherent image in which changes in atomic structure and composition can be interpreted intuitively. This direct image allows the electron probe to be positioned over individual atomic columns for parallel detection electron energy loss spectroscopy (EELS) at a spatial resolution approaching 0.22nm. In this paper we have combined the structural information available in the Z-contrast images with the bonding information obtained from the fine structure within the EELS edges to determine the grain boundary structure in a SrTiO{sub 3} bicrystal.

Polychlorinated azobenzenes (PCABs) can be found as contaminant by products in 3,4-dichloroaniline and its derivatives and in the herbicides Diuron, Linuron, Methazole, Neburon, Propanil and SWEP. Trans congeners of PCABs are physically and chemically more stable and so are environmentally relevant, when compared to unstable cis congeners. In this study, to fulfill gaps on environmentally relevant partitioning properties of PCABs, the values of n-octanol/water partition coefficients (log KOW) have been determined for 209 congeners of chloro-trans-azobenzene (Ct-AB) by means of quantitative structure-property relationship (QSPR) approach and artificial neural networks (ANN) predictive ability. The QSPR methods used based on geometry optimalization and quantum-chemical structural descriptors...

Poly(silylenemethylene)s with the repeating Si–C backbone units are well-examined carbosilane polymers. We synthesized two poly(silylenemethylene)s, poly(diphenyl-silylenemethylene) (PDPhSM) and poly(methyl phenyl-silylenemethylene) (PMPhSM). These two polymers have different physical, thermal and mechanical properties. This work discusses the structures and dynamics of the Si–C backbone and phenyl side groups of these two polymers by 13C and 29Si solid-state NMR and reveals relationships between the thermal and mechanical properties and between structures and dynamics of the Si–C backbone and the side chains.   

Optical spectra of multilayer structures of nanothin films with nanocrystals of defined size and undoped crystals with given content of the impurities were compared. Relationships among the content of impurities, colloids and properties of the initial crystals, and multilayer structures were examined. The influence of surface effects on size-dependent properties of nanothin layers with LiF, CaF2, CdS and CdSe nanocrystals were investigated. Microstructure testing, optical absorption, photoluminescence and nonlinear optical experiments indicate that the possible origins of nanothin layers peculiarities are their purification and the metal excess accumulation in their boundaries.

While several studies have evaluated how the degree of collagen alignment affects the response of soft tissues to tensile loading, the role of fibrillar organization in indentation is less understood. Collagen-based tissue-equivalents (TEs) provide a convenient model system to explore structure-function relationships since their microstructural properties can be easily controlled during fabrication. The purpose of this study was to evaluate the role of initial collagen alignment on the mechanical and structural behavior of soft tissues subjected to indentation using TEs as a model system. Cell-compacted TEs with either isotropic or highly anisotropic fiber alignment were subjected to four-step incremental stress-relaxation indentation tests. The mechanical properties, collagen reorganizati...

A series of novel aromatic diamines containing kinked m-chloro phenyl moiety was synthesized by the reaction of m-chloro benzaldehyde with 2,6-dimethyl aniline. The tetraimide diacid was synthesized by using the prepared diamine with benzophenone tetracarboxylic acid dianhydride (BPTDA) and p-amino benzoic acid. The polymers were prepared by treating the tetraimide diacid with different aromatic diamines. The structures of the monomers and polymers were identified by 1H-NMR, FTIR,13C-NMR and elemental analysis. The polymers showed excellent thermal stability, solubility and mechanical properties. Their structure?property relationship was studied by comparing these m-chloro polymers with polymers containing rigid Pyridine moiety.

Abstract Superporous materials based on two proteins, collagen and sericin were synthesized by freeze-drying considering various ratios between the two proteins. To evaluate the influence of sericin content on the structure/properties relationship, the obtained scaffolds were further characterized using spectroscopic analysis, thermal, and mechanical techniques. Scanning electron microscopy was used to investigate the morphological structure of the scaffolds and the swelling properties as well as the stability of the scaffolds were also assessed. 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

How atoms move in metallic glasses and liquids is an important question in discussing atomic transport, glass formation, structural relaxation and other properties of metallic glasses. While the concept of free-volume has long been used in describing atomic transport, computer simulations and isotope measurements have shown that atomic transport occurs by a much more collective process than assumed in the free-volume theory. We introduce a new approach to describe the atomic dynamics in metallic glasses, in terms of local energy landscapes related to fluctuations in the topology of atomic connectivity. This approach may form the basis for a new paradigm for discussing the structure-properties relationship in metallic glasses.   

This is a section of an online textbook ("Chem 1 Virtual Textbook") on General Chemistry at the first-year college or advanced high-school level. It provides an introduction to the structure and properties of the elements and their relationship to the periodic table of the elements. The six lessons cover quantum theory, the properties of light, the Bohr model of the atom, the quantum model of the atom, electron configurations, and the periodic properties of the elements. Each lesson is accompanied by a concept map.

Carbon nanotubes can be assembled into macroscopic thin film materials called buckypapers. To incorporate buckypaper actuators into engineering systems, it is of high importance to understand their material property-actuation performance relationships in order to model and predict the behavior of these actuators. The electromechanical actuation of macroscopic buckypaper structures and their actuators, including single and multi-walled carbon nanotube buckypapers and aligned single-walled nanotube buckypapers, were analyzed and compared. From the experimental evidence, this Letter discusses the effects of the fundamental material properties, including Young modulus and electrical double layer properties, on actuation performance of the resultant actuators.

HIP-consolidation (Hot Isostatic Pressing or HIPing) of cobalt-based Stellite alloys offers significant technological advantages for components operating in aggressive wear environments. The aim of this investigation was to ascertain the effect of re-HIPing on the HIPed alloy properties for Stellite 4, 6 and 20 alloys. Structure-property relationships are discussed on the basis of microstructural and tribo-mechanical evaluations. Re-HIPing results in coarsening of carbides and solid solution strengthening of the matrix. The average indentation modulus improved, as did the average hardness at micro- and nano-scales. Re-HIPing showed improvement in wear properties the extent of which was dependent on alloy composition.

In recent years, much progress has been made in the studies of nanostructured Al alloys for advanced structural and functional use associated both with the development of novel routes for the fabrication of bulk nanostructured materials using severe plastic deformation (SPD) techniques and with investigation of fundamental mechanisms leading to improved properties. This review paper discusses new concepts and principles in application of SPD processing to fabricate bulk nanostructured Al alloys with advanced properties. Special emphasis is placed on the relationship between microstructural features, mechanical, chemical, and physical properties, as well as the innovation potential of the SPD-produced nanostructured Al alloys.

The electronic and the structural properties of n-GaAs layers grown on rough surface of silicon substrate by molecular beam epitaxy (MBE) has been investigated by photoluminescence (PL), time resolved photoluminescence (TRPL) and high resolution X-ray diffraction (HRXRD). The relationship between electronic and structural properties of the n-GaAs layer was checked, showing that the defect density is a strong cause for trapping the minority carriers. The impact of introducing intermediate rough silicon layer between silicon substrate and n-GaAs layer on the electronic properties was observed, showing that the structure grown on rough Si involves higher lifetime than those developed on flat silicon substrate. Such structure could be used for economic solar cells fabrication.

We introduce graphical time series models for the analysis of dynamic relationships among variables in multivariate time series. The modelling approach is based on the notion of strong Granger causality and can be applied to time series with non-linear dependencies. The models are derived from ordinary time series models by imposing constraints that are encoded by mixed graphs. In these graphs each component series is represented by a single vertex and directed edges indicate possible Granger-causal relationships between variables while undirected edges are used to map the contemporaneous dependence structure. We introduce various notions of Granger-causal Markov properties and discuss the relationships among them and to other Markov properties that can be applied in this context.

Many organic molecules with a high nonlinear polarizability have a "Brooker dye" structure, featuring electron accepting or donating groups separated by an unsaturated (methine or polyene) hydrocarbon bridge. These systems have been the topic of much discussion with regard to their structure-property relationships - particularly relationships linking nonlinear response to bond-length alternation. Here, we show that these relationships can be subsumed within the conceptual framework of a Brooker dye color proposed by Platt [J.R. Platt, J. Chem. Phys. 25 80 (1956)]. The key quantities of Platt's model are the Brooker basicity difference and the isoexcitation energy. These concepts provide a spectroscopic definition of the resonant (cyanine) limit, which is independent of other descriptors commonly used (e.g. bond length alternation). We establish a relation ship between the bond length and the Brooker basicity difference, with which we establish a natural origin for bond length alternation coordinates in asymme...

The thermodynamic stabilities of methanol-bound phenylacetylides and benzyl alkoxides were determined using a FT-ICR mass spectrometer. The complexation energies between anions and methanol were evaluated from the thermochemical cycle. The complexation energy decreases linearly with increasing acidity of the conjugate acid of an anion, giving slopes of 0.54 and 0.61 for phenylacetylide– and benzyl alkoxide–methanol complexes, respectively. These results show that the linear relationship between the complexation energy and acid–base energetics appears to be a general property in the anion–neutral molecule complexes, but the magnitude of the slope of the linear relationships is not simply related to the structure of the hydrogen-bonded complexes.   

Nonlinear 3-D finite element models have been developed to investigate the structural behaviour of unprotected simply supported composite carbon steel and composite stainless steel beam constructions under fire conditions. The nonlinear material properties of carbon steel, stainless steel, composite slim concrete floor and reinforcement bars were incorporated in the models. The interfaces between the composite beam components were also considered allowing the different components to retain its profile during the deformation of the composite beam. The finite element models have been validated against published fire tests. The time-temperature relationships, deformed shapes at failure, time-vertical displacement relationships, failure modes and fire resistances of the composite carbon steel ...

Abstract BACKGROUND: Monoterpenoids are a large group of plant secondary metabolites. Many of these naturally occurring compounds have shown good insecticidal potency on pest insects. Previous studies in this laboratory have indicated that some monoterpenoids have positive modulatory effects on insect GABA receptors. In this study, the key properties of monoterpenoids involved in monoterpenoid binding activity at the housefly GABA receptor were determined by developing quantitative structure-activity relationship (QSAR) models, and the relationship between the toxicities of these monoterpenoids and their GABA receptor binding activities was evaluated. RESULTS: Two QSAR models were determined for nine monoterpenoids showing significant effects on [3H]-TBOB binding and for nine p-menthane an...

Activities in a three year effort in the study of the synthesis of rare earth compounds and an investigation of their magnetic, optical, and semiconducting properties are summarized. The development of the growth of single crystals from the simple face centered cubic magnetic insulating rare earth chalcogenides, to the more complex Th3P4 type structures and lower symmetry layer compounds, is described. Objectives include the synthesis of higher purity materials, the improvement of crystal perfection, and measurement of deviations from stoichiometry. Techniques for growing single crystals of varying compositions of solid solutions between di and trivalent rare earth chalcogenides and methods used for their characterization are developed. The reasoning which led to the variety of experiments referred to in the report is discussed with emphasis on the relationship between magnetic and electronic properties of these systems. The direct relationship of magnetism to the band structure is discussed, as reflected in transport, tunneling and optical measurements. (GRA)

The passive elastic properties of a muscle–tendon complex are usually estimated from the relationship between the joint angle and the passive resistive torque, although the properties of the different structures crossing the joint cannot be easily assessed. This study aimed to determine the passive mechanical properties of the gastrocnemius medialis muscle (GM) using supersonic shear imaging (SSI) that allows the measurement of localized muscle shear modulus (?). The SSI of the GM was taken for 7 subjects during passive ankle dorsiflexion at a range of knee positions performed on an isokinetic dynamometer. The relationship between normalized ? and the length of the gastrocnemius muscle–tendon units (GMTU) was very well fitted to an exponential model (0.944&#...

The representation of the molecular structure by a system (sequence) of amino acids has been used to establish quantitative structure?property/activity relationships (QSPR/QSAR) which can be used for (i) bioactivities of epitope-peptides, (ii) antibacterial potencies of polypeptides, and (iii) the binding affinity of peptides that bind to the class I major histocompatibility complex molecule HLA-A*0201. The representation of the peptide structure has been done via 1-letter abbreviations of amino acids, i.e., A (alanine), C (cysteine), D (aspartic), etc. This approach allows classifying amino acids according to their function in a biochemical process (promoters of increase or decrease of an endpoint).

A relationship between the chemical composition, structure and luminescent properties of light-emitting SiOxNy(Si) composite layers with Si nanocrystals is demonstrated. Photoluminescence (PL) with a maximum of intensity at 500-600 nm is observed in a narrow region of chemical compositions with relatively small Si excess (about 10 at. %). Composite layers structure is studied by means of HRTEM. Appearance of nanocrystals due to annealing is accompanied by substantial growth (30-40 times) of PL intensity but do not change PL spectra shape. Chemical composition of structural luminescent-active complexes with excess Si atomes is determined by XPS technique.

The use of maritime pine sawn timber in structural applications requires knowledge of its mechanical properties. Standards have changed, however, since the last research on this timber was performed. In the present study, 491 beams of maritime pine from Gaelic, of structural-use size but different cross-section, were tested according to these modified standards. Each beam was visually graded according to standard UNE 56.544 and subjected to a four point bending test. The strength classes assigned by the visual grades awarded suggest this material to have greater structural capacity than that currently assumed. The relationships between the modulus of elasticity, strength and density were also examined. (Author) 25 refs.

In this paper we present constructive algorithms for generating realistic synthetic ego networks (one of the most important representations of human social networks). These algorithms are based on ego network models derived in the anthropology literature, which describe the key structural properties of ego networks, and the properties of the social relationships between individuals. The main area we consider for applying these algorithms is the study of social networking environments currently under discussion in the research community. In particular, we focus on two relevant examples, i.e. Mobile Social Networks, and Social Pervasive Networks. In both cases, together with the ego network structural properties, it is fundamental to also describe the statistical properties of the contact pr...

We demonstrate applications of quantitative structure?property relationship (QSPR) modeling to supplement first-principles computations in materials design. We have here focused on the design of polymers with specific electronic properties. We first show that common materials properties such as the glass transition temperature (T g) can be effectively modeled by QSPR to generate highly predictive models that relate polymer repeat unit structure to T g. Next, QSPR modeling is shown to supplement and guide first-principles density functional theory (DFT) computations in the design of polymers with specific dielectric properties, thereby leveraging the power of first-principles computations by providing high-throughput capability. Our approach consists of multiple rounds of validated MQSPR mo...

The dynamic micromechanical and structural properties of single human red blood cells are studied using a combination of dual trap optical tweezers and confocal Raman spectroscopy. Such a combination permits us to show a direct relationship between the rheological properties and chemical structure conformation. The frequency dependence of the complex stiffness of the cells was measured using both one and two probe response functions under identical experimental conditions. Both the microrheology and Raman measurements were performed at different stretching forces applied to the cell. A detailed analysis of the auto- and cross-correlated probe motions allows exploring the local and overall viscoelastic properties of the cells over a controlled range of the deformations. The observed growth of the cell viscoelasticity with stretching was associated with structural changes in the cell membrane monitored via the Raman spectroscopy. PMID:23080020

This paper is to assess effect of the dispersion U3Si2-Al fuel plate with sandwich structure on its mechanical properties and to assess the quality of this fuel plate by the suitable processing because the optimum performance of fuel plate affects directly the safety and reliability of a power reactor. For this purpose, the mechanical properties of the fuel plate with sandwich structure were described that the relationship between the strength and the sandwich microstructure of dispersion U3Si2-Al fuel plate based on the experimental investigations and the fracture analysis of SEM images. These results shown that it can be improved that the mechanical properties of dispersion U3Si2-Al fuel plate with sandwich structure by the optimizing clad material, U3Si2-Al powder composite contents and process of rolling as well as the optimizing the heat treatment methods.

We describe the surface properties of a simple lattice model of a sandpile that includes evolving structural disorder. We present a dynamical scaling hypothesis for generic sandpile automata, and additionally explore the kinetic roughening of the sandpile surface, indicating its relationship with the sandpile evolution. Finally, we comment on the surprisingly good agreement found between this model, and a previous continuum model of sandpile dynamics, from the viewpoint of critical phenomena.

Separator membranes are often the technologically limiting factor in the performance of flowing electrolyte batteries. The increased resistance of an anionic membrane when placed in a FeCl3 solution was related to a decrease in the water content of the membrane. The structure property relationships of anionic permselective membranes was examined. A conductivity model successfully relates the resistance of a membrane to its ion exchange capacity and water content.

Deep-inelastic diffractive scaling provides fundamental insight into the QCD pomeron. It is argued that single gluon domination of the structure function, together with the well-known Regge pole property, determines that the pomeron carries color-change parity C{sub c} = {minus}1 and, at short distances, is in a super-critical phase of Reggeon Field Theory. The main purpose of the talk is to describe the relationship of the super-critical pomeron to QCD.

A novel series of macrocyclic ortho-aminobenzamide Hsp90 inhibitors is reported. A basic nitrogen within the tether linking the aniline nitrogen atom to a tetrahydroindolone moiety allowed access to compounds with good physical properties. Important structure-activity relationship information was obtained from this series which led to the discovery of a soluble and stable compound which is potent in an Hsp90 binding and cell-proliferation assay.

Plasmas exhibiting the ``fishbone`` instability studied on the PBX-M tokamak show a distinct relationship between the plasma shape, the internal magnetic structure, and the presence or absence of fast ion losses associated with the fishbone mode. We have, for the first time, carried out measurements of the magnetic safety factor profile in fishbone-unstable plasmas, and used the knowledge of the associated experimental equilibria to compare the stability and fast ion loss properties of these plasmas with experimental observations.

As mentioned above, the overall goal of this research project was to collect the scientific information essential to develop iron phosphate glass based nuclear wasteforms. The specific objectives of the project were: (1) Investigate the structure of binary iron phosphate glasses and it's dependence on the composition and melting atmosphere: Understand atomic arrangements and nature of the bonding. Establish structure-property relationships. Determine the compositions and melting conditions which optimize the critical properties of the base glass. (2) Understand the structure of iron phosphate wasteforms and it's dependence on the composition and melting atmosphere: Investigate how the waste elements are bonded and coordinated within the glass structure. Establish structure-property relationships for the waste glasses. Determine the compositions and melting atmosphere for which the critical properties of the waste forms would be optimum. (3) Determine the role(s) played by the valence states of iron ions and it's dependence on the composition and melting atmosphere: Understand the different roles of iron(II) and iron(III) ions in determining the critical properties of the base glass and the waste forms. Investigate how the iron valence and its significance depend on the composition and melting atmosphere. (4) Investigate glass forming and crystallization processes of the iron phosphate glasses and their waste forms: Understand the dependence of the glass forming and crystallization characteristics on overall glass composition and valence states of iron ions. Identify the products of devitrification and investigate the critical properties of these crystalline compounds which may adversely affect the chemical and physical properties of the waste forms.

The exceptionally high specific stiffness and strengths reported for carbon nanotubes, combined with their fiber-like structure, has stimulated research in the development of polymer nanocomposites reinforced with carbon nanotubes. Before these extraordinary properties observed at the nano-scale are realized in a macroscopic composite, considerable basic research is necessary. This research work seeks to obtain a fundamental understanding of the processing/structure/property relations in carbon nanotube-reinforced composites through integrated research on processing and characterization of model nanocomposite systems as well as development of predictive models for the nanocomposite elastic properties. Ultimately, establishment of these basic relationships will enable the nanoscale design of nanotube-reinforced materials. In this work, a novel technique to produce continuous nanocomposite ribbons of aligned multi-walled carbon nanotubes embedded in a polystyrene thermoplastic matrix was developed. This model nanocomposite system serves as a basis for the investigation of structure/property relationships through characterization of their elastic and fracture behavior. Based on characterization results and numerical simulations, a micromechanics-based modeling technique is developed to describe the structure/size influence of the nanotube reinforcement on the elastic modulus of these nanocomposites. To reveal the hierarchy of nanotube reinforcement, multi-scale hybrid composites, where a nanotube composite sheath surrounds traditional carbon fibers, were produced and the influence of selective reinforcement on load transfer at the fiber/matrix interface was examined.

Recently, rubber nanocomposites reinforced with a low volume fraction of nanofillers have attracted great interest due to their fascinating properties. Incorporation of nanofillers such as layered and fibrillated silicate clays, carbon nanotubes and nanofibers, calcium carbonate, metal oxides, or silica nanoparticles into elastomers can significantly improve their mechanical, thermal, dynamic mechanical, electrical, aging, barrier, adhesion, and flame retardancy properties. These also significantly alter the rheological behavior of polymers, even at low filler loading. The properties of nanocomposites depend greatly on the structure of the polymer matrices, the nature of nanofillers, and the method by which they are prepared. It has been established that uniform dispersion of nanofillers in rubber matrices is a general prerequisite for achieving desired mechanical, rheological, and physical characteristics. This review paper addresses some recent developments on the morphology-property relationship of rubber-based nanocomposites reinforced with various nanoparticles. New insights into understanding the properties of these nanocomposites and morphology development will be discussed.

In the electroceramic SrTiO{sub 3} the grain boundary atomic structure governs a variety of electrical properties such as non-linear I-V characteristics. An understanding of this atomic structure-property relationship for individual grain boundaries requires a technique which probes both composition and chemical bonding on an atomic scale. Atomic structure models for tilt boundaries in SrTiO{sub 3} bicrystals have been determined directly from experimental data, by combining high-resolution Z-contrast imagine to locate the cation columns at the boundary, with simultaneous electron energy loss spectroscopy to examine light element coordination at atomic resolution. In this paper we compare and contrast the grain boundary structure models of symmetric and asymmetric boundaries in SrTiO{sub 3}.

In-situ neutron diffraction combined with AC impedance spectroscopy was applied successfully to investigate the correlation between crystal structure and electrical properties of the La{sub 2}Mo{sub 2}O{sub 9} oxide ion conducting electrolyte material. Neutron diffraction patterns were collected as a function of temperature while the AC impedance spectra were recorded simultaneously using a modified sample environment to monitor the conductivity change of the sample. A close relationship between unit cell parameters and the bulk conductivity was observed, confirming that the oxygen transport is dependent on the lattice structure. With the transition from the low temperature alpha to the high temperature beta phase, expansion of the crystal structure makes more space available for oxygen transport, leading to a dramatic increase of the ionic conductivity. The successful application of this technique provides a new method to simultaneously investigate crystal structure and electrical properties in electro-ceramics in the future.

Living organisms produce metabolites of many types via their metabolisms. Especially, flavonoids, a kind of secondary metabolites, of plant species are interesting examples. Since plant species are believed to have specific flavonoids with respect to diverse environment, elucidation of design principles of metabolite distributions across plant species is important to understand metabolite diversity and plant evolution. In the previous work, we found heterogeneous connectivity in metabolite distributions, and proposed a simple model to explain a possible origin of heterogeneous connectivity. In this paper, we show further structural properties in the metabolite distribution among families inspired by analogy with plant-animal mutualistic networks: nested structure and modular structure. An earlier model represents that these structural properties in bipartite relationships are determined based on traits of elements and external factors. However, we find that the architecture of metabolite distributions is desc...

The objectives of the proposed research program are to study graft copolymerization of vinyl monomers onto cellulose or cellulose derivatives. Grafting will be carried out by redox initiation such as Ce/sup 4 +/, by thermal decomposition (cellulose xanthates), or by nucleophilic displacement of cellulose derivatives by ''living'' polymers. The structure of the resulting water-soluble graft copolymer will be determined as well as the grafting efficiency of the initiation systems. Cellulose derivatives containing side chains capable of micellization will also be synthesized. In support of these objectives, water-soluble, block-, star- and cyclic polymers will be synthesized in order to aid in establishing property-structure relationships. Characterization of the polymers will be carried out by IR and by proton or carbon-13 NMR as well as size exclusion chromatography, viscometry, osmometry and other physico chemical techniques. Rheological studies designed to clarify structure-rheology relationships are also planned. 54 refs.

A new actin cytoskeleton microstructural model based on the semiflexible polymer nature of the actin filament is proposed. The relationship between the stretching force and the mechanical properties of cells was examined. Experiments on deforming hematopoietic cells with distinct primitiveness from normal and leukemic sources were conducted via optical tweezer manipulation at single-cell level. The modeling results were demonstrated to be in good agreement with the experimental data. We characterized how the structural properties of the actin cytoskeleton, such as prestress, density of cross-links, and actin concentration, affect the mechanical behavior of cells based on the proposed model. Increasing prestress, actin concentration, and density of cross-links reduced cell deformation, and ...

In this overview paper, novel rare-earth doped silicon nitride based phosphors for white LEDs applications have been demonstrated. The luminescence properties of orange-red-emitting phosphors (M2Si5N8:Eu2+) and green-to-yellow emitting phosphors (MSi2N2O2:Eu2+, M = Ca, Sr, Ba) are discussed in detail with a focus on the relationship between the properties and structures. With high conversion efficiency in the near UV/blue region, along with high chemical/physical stability, Eu2+ - and Ce3+ - activated alkaline-earth silicon nitride and oxynitride materials are excellent wavelength-conversion phosphors for white LEDs.

Scand J Caring Sci; 2012; 26; 607-614 Psychometric properties of three instruments to measure recovery Background:- The process of recovery is gaining more and more attention within health care for patients with severe mental illness. Therefore, instruments to measure recovery can be useful for clinical and research purposes. Aims:- This study evaluates the psychometric properties of three instruments pertaining to recovery for possible application in the Netherlands. The Recovery Attitude Questionnaire and the Recovery Knowledge Inventory were investigated among 210 mental health professionals, and the Recovery Promoting Relationship Scale was administered to 142 mental health consumers. Methods:- The factor structure, reliability and internal consistency were examined using the same anal...

In many materials, mechanistic understanding of material microstructure/property relationships requires knowledge of alloy structures at the atomic scale. This remains one of the main challenges of materials science. Historically, because of insufficient spatial resolution of available microstructural techniques, theories relating the role of alloying elements to materials properties were inferred from phenomenological studies. More recently, with the advent of techniques such as atom-probe tomography the spatial resolution limits have been dramatically improved. For instance, since the speculation by Cottrell and Bilby in 1949, it was generally believed that solute segregation at dislocations leads to strain hardening, but the direct proof came only recently when Blavette et al. (Nature, ...

The synthesis of 2,6-dinitro-4-pentafluorosulfanyl-N,N-dipropylaniline, 2, was achieved in a straightforward manner from commercially available 1-nitro-4-pentafluorosulfanylbenzene. In post-emergence screening 2 was found to be approximately twice as potent as trifluralin with the same general spectrum of activity. In contrast, in pre-emergence tests, 2 was nearly 5 fold more potent against quackgrass and crabgrass. Given the existing structure–activity-relationship for adverse properties of the dinitroaniline herbicides, 2 is proposed to have properties quite comparable to the commercial agent trifluralin.   

Abstract Perylene monoimide (PMI) was brominated to give tetra- and tribrominated molecules, which underwent a Suzuki coupling reaction with 4-(diphenylamino)phenylboronic acid to give PMI derivatives. The photophysical and electrochemical properties of the synthesized compounds were investigated, and theoretical calculations were performed. Single crystals of tetrasubstituted PMI were grown and studied in detail. The structure-property relationships were examined to reveal the effect of the position and number of substituents on the perylene core unit. All molecules showed a broad absorption up to 750-nm. Corresponding anhydrides of PMIs were used for fabrication of dye-sensitized solar cells. The molecule with four triphenylamine units on perylene monoanhydride showed the highest power c...

A novel piezochromic fluorescent (PCF) compound with aggregation-induced emission (AIE) effect and morphology-alterable emission property was developed. The amorphous and crystalline aggregates were obtained, and their spectroscopic properties and morphological structures were reversibly and repeatedly exhibited upon pressing (fuming) or annealing. The piezochromic fluorescent nature was generated through crystalline-amorphous phase transformation. It was proposed that AIE compounds existing a twisted propeller-shaped conformation will exhibit PCF activity. The common relationship betweeen AIE and PCF established will guide researchers in identifying and synthesizing more piezochromic fluorescent materials.

Abstract A nanocomposite of Poly(vinylidene fluoride) (PVDF) was prepared with graphene sheets (GSs), which are a novel filler by a solution method. The structure-properties relationships of PVDF/GSs nanocomposites were studied. The results of differential scanning calorimetry and X-ray diffraction show that addition of GSs to the PVDF matrix promotes an phase to phase transformation of the polymer crystal. The nanocomposites exhibit significant increases in dynamic mechanical properties and thermal stability compared to the neat PVDF. In addition, the incorporation of GSs in PVDF indicated excellent optical transparency at the lowest weight fractions of GSs and modified wettability of PVDF. POLYM. COMPOS., 2011. 2011 Society of Plastics Engineers

Asphalt cements (AC) are highly complex mixtures, and many research projects have been devoted to elucidating the relationships between asphalt structure and properties. In this work the authors present how Differential Scanning Calorimetry can be used to determine quantitatively the thermal behavior of AC. The purpose is to develop a thermoanalytical method that is able to determine the glass transition temperature of AC; to quantify the microcrystallization of aliphatic molecules; and to correlate the results with other physical and rheological properties of the asphalts.

Recent investigations have demonstrated that materials with ultrafine grain (UFG) structure (nano- and submicron crystalline) can be processed by severe plastic deformation. One advantage of this method is that it can be applied to both pure metals and alloys. Moreover, it produces samples that have no residual porosity so that meaningful measurements of the physical and mechanical properties are possible. Investigations of ultrafine grain copper and aluminum alloys have revealed a number of specific features of their mechanical behavior, namely extremely high hardness and strength, the absence of strain hardening, and deviation form the Hall-Petch relationship. In this work the authors investigate the mechanical properties and thermal stability of UFG titanium.

Dielectric properties and charge compensation of Li and Co co-doped NiO (LCNO) ceramics prepared by a simple sol-gel route have been investigated. The concentration of Co makes a great influence on microstructure, dielectric properties and charge compensation mechanism of the LCNO ceramics. Grain size of the ceramics increases from 5.6mm to 7.2mm with dependence on Co concentration. By using a complex impedance analysis at different temperatures, the samples exhibit an electrically heterogeneous structure, which is responsible for a giant dielectric permittivity. The relationship between the activation energies of dielectric relaxation and conduction and charge compensation mechanism in this system were discussed.

We have developed LiIO3/laponite nanocomposite thin films to form waveguides with quadratic nonlinear optical properties. The films are dip-coated and annealed to induce LiIO3 crystallisation within the laponite matrix. LiIO3 nanocrystal orientation can be controlled using an electric field during the annealing process. In this article we perform the characterisations of the nanocomposite films through m-line spectroscopy and second harmonic generation microscopy (SHGM). Both refractive indexes deduced from m-line spectra and the SHG signal are shown to depend on the nanocrystal orientation distribution, and a relationship between the optical properties and microscopic structure of the films is developed.   

Abstract We present a joint experimental-theoretical study of the reflectance anisotropy of clean and gold-covered Si(557), a vicinal surface of Si(111) upon which gold forms quasi-one-dimensional (1D) chains parallel to the steps. By means of first-principles calculations, we analyse the close relationship between the various surface structural motifs and the optical properties. Good agreement is found between experimental and computed spectra of single-step models of both clean and Au-adsorbed surfaces. Spectral fingerprints of monoatomic gold chains and silicon step edges are identified. The role of spin-orbit coupling (SOC) on the surface optical properties is examined, and found to have little effect.

This paper deals recent studies on molecular design and utilization of boron compounds in polymer electrolytes. Well designed boron compounds have been used as dissociative lithium salts or anion receptors for enhancement of ionic conductivity and lithium ion transference number. Boron-containing polymers have not only anion trapping ability but also improving effects on properties of interface between electrolytes and electrodes. Special ion conduction phenomena in polymer electrolytes have been found using insoluble lithium orthoborates or a boric ester with crown ether substituents. Relationships between structures of boron compounds and properties of polymer electrolytes are discussed, and future directions of investigation on boron compounds for high-performance polymer electrolytes are outlined.

Progress is reported for an investigation of the influence of conditions of hot working on the properties of alloys at high temperatures. Conditions of working can be used to control microstructural variations in a manner which cannot be obtained in any other procedure and is capable of developing structures superior in properties to any other treatment. The major objective is to define the basic principles involved so that they can be applied to the general problem of developing optimum properties in any alloy. The relatively simple structure of "A" Nickel is being used as an experimental material for study of the role of working for properties in the as-worked condition. A-286 alloy is being used as an example of a matertal whose properties are influenced after solution and aging treatments by the conditions of prior working. The results reported cover the initial surveys of the relationships of working conditions to creep and rupture properties. Structural analyses to define the basic principles involved were confined to preliminary partial studies. The investigation is being continued with emphasis on the structural studies. (auth)

Summary Bent-core mesogens have gained considerable importance due to their ability to form new mesophases with unusual properties. Relationships between the chemical structure of bent-core molecules and the type and physical properties of the formed mesophases are relatively unknown in detail and differ strongly from those known for calamitic liquid crystals. In this paper symmetric and nonsymmetric five-ring salicylideneaniline-based bent-core mesogens are presented, and the effect of lateral substituents attached at the outer phenyl rings (F, Cl, Br) or the central phenyl ring (CH3) on the liquid-crystalline behaviour and on the physical properties is studied. Corresponding benzylideneaniline-based compounds were additionally prepared in order to study the influence of the intramolecular hydrogen bond. The occurring mesophases were investigated by differential scanning calorimetry, polarising microscopy, X-ray diffraction and dielectric and electro-optical measurements. The paper reports on new findings with respect to the structure–property relationships of bent-core mesogens. On one hand, the disruptive effect of laterally substituted halogen atoms, F, Cl and Br, on the mesophase behaviour of three isomeric series was much lower than expected. On the other hand, an increase of the clearing temperature by 34 K was observed, caused by small lateral substituents. The electro-optical behaviour, especially the type of polar switching and corresponding molecular movements, is sensitive to variations in the molecular structure.

Systematic shock recovery experiments, in which microstructural and mechanical property effects are characterized quantitatively, constitute an important means of increasing our understanding of shock processes. Through studies of the effects of variations in metallurgical and shock loading parameters on structure/property relationships, the micromechanisms of shock deformation, and how they differ from conventional strain rate processes, are beginning to emerge. This paper will highlight the state-of-the-art in shock recovery of metallic and ceramic materials. Techniques will be described which are utilized to ''soft'' recover shock-loaded metallic samples possessing low residual strain; crucial to accurate ''post-mortem'' metallurgical investigations of the influence of shock loading on material behavior. Illustrations of the influence of shock assembly design on the structure/property relationships in shock-recovered copper samples including such issues as residual strain and contact stresses, and their consequences are discussed. Shock recovery techniques used on brittle materials will be reviewed and discussed in light of recent experimental results. Finally, shock recovery structure/property results and VISAR data on the /alpha/--/omega/ shock-induced phase transition in titanium will be used to illustrate the beneficial link between shock recovery and ''real-time'' shock data. 26 refs., 3 figs.

Although the structures of the wild type (WT) and mutants (A53T, A30P, E46K) of ?-synuclein (?-syn) proteins related to Parkinson's disease have been studied extensively using both experimental and theoretical tools, the relationships between the structural properties and thermodynamic preferences at a molecular level with dynamics are unknown. Such an understanding is required for accessing detailed knowledge regarding to the ``early aggregation and monomer'' hypothesis in Parkinson's disease. We investigated the impact of these single point mutations on the structures and conformational preferences of ?-syn monomers in aqueous solution as well as the impact of the aqueous solution environment on the proteins. Obtained qualitative and quantitative results provide new insights into the structure-function relationships of these proteins and help us to understand the molecular mechanism hidden behind the ``early aggregation and monomer'' hypothesis. Our results show that the tertiary structure of the ?-syn proteins varies significantly with dynamics, however, this variability is not easily reflected in the changes of the relative amounts of the secondary structural components. The obtained structures also demonstrate that a single point mutation can have a significant effect on protein folding. The structures of each of the WT, A53T, A30P, and E46K ?-syn monomers differ from each other throughout and the presence of aqueous solution significantly impacts the ?-syn protein structures.

The values of the soil sorption coefficient (KOC) have been computed for 209 environmentally relevant trans polychlorinated azobenzenes (PCABs) lacking experimental partitioning data. The quantitative structure-property relationship (QSPR) approach and artificial neural networks (ANN) predictive ability used in models based on geometry optimalization and quantum-chemical structural descriptors, which were computed on the level of density functional theory (DFT) using B3LYP functional and 6-311++G** basis set and of the semi-empirical quantum chemistry method for property parameterization (PM6) of the molecular orbital package (MOPAC). An experimentally available data on physical and chemical properties of PCDD/Fs and PCBs were used as reference data for the QSPR models and ANNs predictions...

Abstract This research work has concerned a study on relationship between structure and properties of maleated thermoplastic starch (MTPS)/plasticized poly(lactic acid) (PLA) blend. The aim of this work is to investigate the effects of blending time, temperature, and blend ratio on mechanical, rheological, and thermal properties of the blend. The MTPS was prepared by mixing the cassava starch with glycerol and maleic anhydride (MA). Chemical structure of the modified starch was characterized by using a FTIR technique, whereas the degree of substitution was determined by using a titration technique. After that, the MTPS prepared by 2.5 pph of MA was further used for blending with triacetin-plasticized PLA under various conditions. Mechanical, thermal, and rheological properties of the blend...

Interfaces, such as grain boundaries, phase boundaries, and surfaces, are important in materials of any microstructural size scale, whether the microstructure is coarse-grained, ultrafine-grained, or nano-grained. In nanostructured materials, however, they dominate material response and as we have seen many times over, can lead to extraordinary and unusual properties that far exceed those of their coarse-grained counterparts. In this article, we focus on bimetal interfaces. To best elucidate interface structure-property-functionality relationships, we focus our studies on simple layered composites composed of an alternating stack of two metals with bimetal interfaces spaced less than 100 nm. We fabricate these nanocomposites by either a bottom-up method (physical vapor deposition) or a top-down method (accumulative roll bonding) to produce two distinct interface types. Atomic-scale differences in interface structure are shown to result in profound effects on bulk-scale properties.

Abstract This work establishes a Quantitative Structure-Property Relationships (QSPR) based analysis with the aim of interpreting both the structural and electronic properties of the polar region of valproic acid and its derivatives, in terms of stabilizing intramolecular interactions related to the involved substituents. We consider ten different calculated properties as dependent variables for the QSPR models: the bond lengths C8O9, C8X10, and the percentage of s-character of the natural hybrids forming the bonding orbitals of the O9C8X10 region. The representative descriptors are the charges transferred during donor/acceptor interactions around this function calculated at the B3LYP/6-311++G**(6d,10f) level of theory, and/or hybrid descriptors derived therefrom. The models so established...

Polystyrene (PS) and poly(methyl methacrylate) (PMMA) blends filled with octadecylamine-functionalized graphene (GE-ODA) have been fabricated to obtain conductive composites with a lower electrical percolation threshold according to the concept of double percolation. The dependence of the electrical properties of the composites on the morphology is examined by changing the proportion of PS and PMMA. Our results reveal that the electrical conductivity of the composites can be optimal when PS and PMMA phases form a cocontinuous structure and GE-ODA nanosheets are selectively located and percolated in the PS phase. For the PS/PMMA blend (50w/50w), the composites exhibit an extremely low electrical percolation threshold (0.5 wt %) because of the formation of a perfect double percolated structure. Moreover, the rheological properties of the composites are also measured to gain a fundamental understanding of the relationship between microstructure and electrical properties. PMID:22950786

Particulate materials with unique functional properties have been the focus of much attention in recent years. Of particular interest, due to their considerable scientific and technological importance, are particles coated with nanoparticles. These have greatly stimulated interest for their novel structure and properties. In these kinds of particulate materials, the interface structures between the support particle and the nanoparticle play a crucial role in controlling their properties. Consequently, imaging of the atomic structures at the interfaces can provide deep understanding of the relationship between the particulate and the corresponding properties. Z-contrast scanning transmission electron microscope (STEM) provides a new view of materials on the atomic scale, a direct image of atomic structure composition which can be interpreted without the need for any preconceived model structure. Therefore it is a powerful tool in the study of particulate materials. In this report, the authors present the structures of 18 micron diameter alumina particles coated with Ag nanoparticles. Particulates were prepared by a laser ablation technique, which involves laser ablation of the target material (Ag) onto a fluidized bed of core particles (alumina). The core alumina particles were fluidized inside the deposition system using a mechanical vibration method. For the STEM analysis, the particulates were lightly crushed in water using a pestle and mortar, then diluted in ethanol and deposited on a TEM grid coated with an amorphous carbon thin film.

The potential (eco)toxicological hazard posed by engineered nanoparticles is a major scientific and societal concern since several industrial sectors (e.g. electronics, biomedicine, cosmetics) are exploiting the innovative properties of nanostructures resulting in their large-scale production. Many consumer products contain nanomaterials and, given their complex life-cycle, it is essential to anticipate their (eco)toxicological properties in a fast and inexpensive way in order to mitigate adverse effects on human health and the environment. In this context, the application of the structure-toxicity paradigm to nanomaterials represents a promising approach. Indeed, according to this paradigm, it is possible to predict toxicological effects induced by chemicals on the basis of their structural similarity with chemicals for which toxicological endpoints have been previously measured. These structure-toxicity relationships can be quantitative or qualitative in nature and they can predict toxicological effects directly from the physicochemical properties of the entities (e.g. nanoparticles) of interest. Therefore, this approach can aid in prioritizing resources in toxicological investigations while reducing the ethical and monetary costs that are related to animal testing. The purpose of this review is to provide a summary of recent key advances in the field of QSAR modelling of nanomaterial toxicity, to identify the major gaps in research required to accelerate the use of Quantitative Structure-Activity Relationship (QSAR) methods, and to provide a roadmap for future research needed to achieve QSAR models useful for regulatory purposes. PMID:23165187

The geometric structures for ferromagnetic Zn1-xCrxTe films grown by molecular beam epitaxy were investigated by fluorescence XAFS measurements in order to elucidate the relationship between the geometric structure and the magnetic properties. XAFS analysis suggested that the majority of Cr atoms doped in CrTe substituted the Zn-site in the ZnTe lattice below the Cr content x = 0.048, and formed Cr-Te compounds such as Cr2Te3 and CrTe above x = 0.090. It is suggested that ferromagnetism of the Zn1-xCrxTe films above x = 0.090 is due to the formation of Cr-Te compounds.

Curcumin (a major constituent of widely-used spice and colouring agent, turmeric) was found to be very effective in antagonising the S9-mediated mutagenicity of several food-derived heterocyclic amines. In order to understand the chemical basis of antimutagenic properties of curcumin against these mutagens, we have studied the structure-activity relationship between curcumin and its naturally-occurring derivatives, namely demethoxycurcumin and bisdemethoxycurcumin, and other structurally-related natural and synthetic analogues of curcumin, namely tetrahydrocurcumin, dibenzoylmethane, dibenzoylpropane, vanillin, ferulic acid, isoferulic acid and caffeic acid, using Ames Salmonella/reversion assay, against different classes of cooked food mutagens. We conclude that unsaturation in the side c...

A set of thermoviscoplastic nonlinear constitutive relationships (1VP-NCR) is presented. The set was developed for application to high temperature metal matrix composites (HT-MMC) and is applicable to thermal and mechanical properties. Formulation of the TVP-NCR is based at the micromechanics level. The TVP-NCR are of simple form and readily integrated into nonlinear composite structural analysis. It is shown that the set of TVP-NCR is computationally effective. The set directly predicts complex materials behavior at all levels of the composite simulation, from the constituent materials, through the several levels of composite mechanics, and up to the global response of complex HT-MMC structural components.

Using semiempirical quantum chemical descriptors, by partial least squares (PLS) regression, quantitative structure-property relationships (QSPRs) were established for direct photolysis quantum yields () and rate constants (k) of polybrominated diphenyl ether congeners dissolved in water/methanol and methanol solutions, respectively, and irradiated by artificial ultraviolet A light. Formula Not Shown , a parameter indicating robustness and predictive abilities of PLS models, for the significant QSPR models is larger than 0.702. The gap of frontier molecular orbital energies (ELUMO-EHOMO) and the most positive Mulliken atomic charges on a hydrogen atom ( Formula Not Shown ) are two main molecular structural factors governing the log values. log increases with increasing ELUMO-EHOMO and Form...

Although few studies have systematically investigated the relationship between visual mental imagery and visual working memory, work on the effects of passive visual interference has generally demonstrated a dissociation between the two functions. In four experiments, we investigated a possible commonality between the two functions: We asked whether both rely on depictive representations. Participants judged the visual properties of letters using visual mental images or pictures of unfamiliar letters stored in short-term memory. Participants performed both tasks with two different types of interference: sequences of unstructured visual masks (consisting of randomly changing white and black dots) or sequences of structured visual masks (consisting of fragments of letters). The structured vi...

We propose a model of irregular shaped ice particles for satellite and ground-based cloud remote sensing applications. Microphysical observations have shown that ice particles generated in convective clouds tend to have highly irregular structures as a result of aggregation process. To simulate such complex structures, we used spatial Poisson-Voronoi tessellations. Furthermore, we adopted fractal-like shapes that were consistent with the proposed mass-dimension and area ratio-dimension relationships of measured cirrus particles. Single-scattering properties of the modeled ''Voronoi aggregates'' at visible wavelengths with size parameters up to 2246 were estimated from numerical calculations using the finite-difference time-domain method and the geometrical-optics integral-equation method. ...

This study aims to develop new environmentally friendly construction materials that compete with modern materials in civil engineering. The paper deals in particular with tropical clays in order to develop new processing of clay based construction materials such as bricks, roof and floor tiles, for building needs in developing countries. Physical and thermo-mechanical characterisations are carried out on six tropical clay varieties from Togo (West Africa). The mechanical resistance is carried out on clay structures fired at 500^oC, 850^oC and 1060^oC. Relationships between the physical properties and the mechanical characteristics of clay structures have been established.

In order to explore the structural determinants for the TRPV1 and TRPA1 agonist properties of gingerols, a series of nineteen analogues (1b-5) of racemic [6]-gingerol (1a) was synthesized and tested on TRPV1 and TRPA1 channels. The exploration of the structure-activity relationships, by modulating the three pharmacophoric regions of [6]-gingerol, led to the identification of some selective TRPV1 agonists/desensitizers of TRPV1 channels (3a, 3f, and 4) and of some full TRPA1 antagonists (2c, 2d, 3b, and 3d). PMID:22257892

In this article, we study finite dynamical systems defined over graphs, where the functions are applied asynchronously. Our goal is to quantify and understand stability of the dynamics with respect to the update sequence, and to relate this to structural properties of the graph. We introduce and analyze three different notions of update sequence stability, each capturing different aspects of the dynamics. When compared to each other, these stability concepts yield vastly different conclusions regarding the relationship between stability and graph structure, painting a more complete picture of update sequence stability.

The method of process averaging in periodic media is applied to the dynamic coupled elasticity problem for composites with a regular structure. Relationships for the effective thermoelastic and thermophysical characteristics of an equivalent homogeneous medium are obtained from solutions to auxiliary local problems for a periodicity cell. Numerical calculations of effective thermoelastic characteristics are presented for unidirectional fiber composites. The dependence of effective composite properties on the volume fraction of the components and the geometrical structure of the periodicity cell is analyzed. 9 references.

This study investigates the rheological properties, elastohydrodynamic film thickness, and friction coefficients of several commercially available polyalphaolefin (PAO) and polydimethylsiloxane (PDMS)-based lubricants to assess relationships between molecular structure and lubricant performance. Molecular structures and masses were determined by nuclear magnetic resonance spectroscopy and gel permeation chromatography, respectively. Density and viscosity are measured from 303 to 398 K, while elastohydrodynamic lubricant film thickness and friction measurements were made at temperatures, loads, and speeds that are representative of boundary, mixed, and full-film lubrication regimes. The results show that PDMS-based lubricants are thermally and oxidatively more stable than PAOs, while the vi...

Computer-assisted screening for Kohonen self-organizing maps in terms of the quantitative structure?activity relationship (QSAR) model revealed the high potential activity of cinnamoyl derivatives of coumarin and dehydroacetic acid and their boron difluoride complexes against a number of biological targets, including HIV-1 integrase. The pronounced inhibitory properties of dehydroacetic acid derivatives and their boron difluoride complexes against HIV-1 integrase were experimentally confirmed by in vitro testing of their antiviral activity with respect to HIV-infected cells. The data obtained suggests a correlation between the structure of the compounds studied and their biological activity.

We derive structure-property relationships for methine ("Brooker") dyes relating the color of the dye and its symmetric parents to its bond alternation in the ground state and also to the dipole properties associated with its low-lying charge-resonance (or charge-transfer) transition. We calibrate and test these relationships on an array of different protonation states of the green fluorescent protein chromophore motif (an asymmetric halochromic methine dye) and its symmetric parent dyes. The relationships rely on the assumption that the diabatic states that define the Platt model for methine dye color [J. R. Platt, J. Chem. Phys. 25, 80 (1956)] can also be distinguished by their single-double bond alternation and by their charge localization character. These assumptions are independent of the primary constraint that defines the diabatic states in the Platt model--specifically, the Brooker deviation rule for methine dyes [L. G. S. Brooker, Rev. Mod. Phys. 14, 275 (1942)]. Taking these assumptions, we show that the Platt model offers an alternate route to known structure-property relationships between the bond length alternation and the quadratic nonlinear polarizability ?. We show also that the Platt model can be parameterized without the need for synthesis of the symmetric parents of a given dye, using the dipole data obtained through spectroscopic measurements. This suggests that the Platt model parameters may be used as independent variables in free-energy relationships for chromophores whose symmetric parents cannot be synthesized or chromophores strongly bound to biomolecular environments. The latter category includes several recently characterized biomolecular probe constructs. We illustrate these concepts by an analysis of previously reported electroabsorption and second-harmonic generation experiments on green fluorescent proteins. PMID:21428645

A macroscopic-modeling methodology to account for the chemical and structural properties of fuel-cell diffusion media is developed. A previous model is updated to include for the first time the use of experimentally measured capillary pressure -- saturation relationships through the introduction of a Gaussian contact-angle distribution into the property equations. The updated model is used to simulate various limiting-case scenarios of water and gas transport in fuel-cell diffusion media. Analysis of these results demonstrate that interfacial conditions are more important than bulk transport in these layers, where the associated mass-transfer resistance is the result of higher capillary pressures at the boundaries and the steepness of the capillary pressure -- saturation relationship. The model is also used to examine the impact of a microporous layer, showing that it dominates the response of the overall diffusion medium. In addition, its primary mass-transfer-related effect is suggested to be limiting the water-injection sites into the more porous gas-diffusion layer.

The structural and thermodynamic properties of the non-oxide superconductor ZnNNi3 are investigated by using ab initio plane-wave pseudo potential density functional theory method within the generalized gradient approximation (GGA). The calculated lattice constants, the bulk modulus and its pressure derivative, and elastic constants of ZnNNi3 at zero temperature and pressure are in good agreement with the available theoretical and experimental data. The thermodynamic properties of ZnNNi3 are predicted by using the quasi-harmonic Debye model. The pressure-volume-temperature (P-V-T) relationship, the bulk modulus B0 and bulk modulus B, the variations of the thermal expansion coefficient ? and the heat capacity CV, CP with pressure P and temperature T, as well as the Grüneisen parameter-pressure-temperature ? (?-P-T) relationships are obtained systematically in the ranges of 0–70 GPa and 0–1000 K.   

Bridged polysilsesquioxanes are a class of hybrid organic-inorganic materials that permit molecular engineering of bulk properties including porosity. Prepared by sol-gel polymerization of monomers with two or more trialkoxysilyl groups, the materials are highly cross-linked amorphous polymers that are readily obtained as gels. The bridging configuration of the hydrocarbon group insures that network polymers are readily formed and that the organic functionality is homogeneously distributed throughout the polymeric scaffolding at the molecular level. This permits the bulk properties, including surface area, pore size, and dielectric constant to be engineered through the selection of the bridging organic group. Numerous bridging groups have been incorporated. This presentation will focus on the effects that the length, flexibility, and substitution geometry of the hydrocarbon bridging groups have on the properties of the resulting bridged polysilsesquioxanes. Details of the preparation, characterization, and some structure property relationships of these bridged polysilsesquioxanes will be given.

The microstructure and properties of a hot rolled-quenched Cu-Cr-Zr-Mg-Si alloy were investigated by transmission electron microscopy observations, micro-hardness and tensile strength testing, and electrical conductivity measurement. The results show that the hot rolling-quenching (HR-Q) process and subsequent thermomechanical treatments are successfully developed to manufacture Cu-Cr-Zr-Mg-Si alloy strips. Solution treatment can be finished during the HR-Q process, and good combinations of strength, conductivity, and softening resistance are obtained for the thermomechanically treated strips. Ordered fcc structure precipitates which exhibit a cube-on-cube orientation relationship with the matrix are responsible for the improvements of properties. The properties of hot rolled-quenched Cu-Cr-Zr-Mg-Si alloy strips can be further improved by two-step rolling and aging process. The improvements of properties are attributed to the interactions of precipitation strengthening and strain hardening.

We have conducted Stokesian dynamics simulations to investigate the dynamic properties of ferromagnetic colloidal dispersions subjected to a sinusoidal shear flow. Thick chainlike cluster formation is significantly influenced by an oscillatory shear flow even if the amplitude is relatively small, since the internal structures of thick chainlike clusters are highly sensitive to the change in the direction of the shear flow. The motions of thick chainlike clusters are out of phase to a sinusoidal shear rate, and this phase difference is strongly correlated with that of the viscosity and normal stress coefficients. The viscoelastic properties become more apparent with decreasing frequency of the oscillatory shear flow, since such properties have a strong relationship with thick chainlike cluster formation. In other words, since thick chainlike clusters are more stable for the case of a smaller frequency shear flow, such stable clusters induce significant viscoelastic properties of ferromagnetic colloidal dispersions in a strong applied magnetic field. (author)

Zosterin, an apiose-rich pectic polysaccharide, was extracted and purified from the sea grass Zostera marina. Structural studies conducted by gas chromatography and NMR spectroscopy on a purified zosterin fraction (AGU) revealed a typical apiogalacturonan structure comprising an alpha-1,4-d-galactopyranosyluronan backbone substituted by 1,2-linked apiofuranose oligosaccharides and single apiose residues. The average molecular mass of AGU was estimated to be about 4100 Da with a low polydispersity. AGU inhibited proliferation of A431 human epidermoid carcinoma cells with an approximate IC(50) value of 3 microg/mL (0.7 microM). In addition, AGU inhibited A431 cell migration and invasion. Preliminary experiments showed that inhibition of metalloproteases expression could play a role in these antimigration and anti-invasive properties. Autohydrolysis of AGU, which eliminated apiose and oligo-apiose substituents, led to a virtual disappearance of cytotoxic properties, thus suggesting a direct structure-function relationship with the apiose-rich hairy region of AGU. PMID:20465284

NaChBac from Bacillus halodurans is a bacterial homologue of mammalian voltage-gated sodium channels. It has been proposed that a NaChBac monomer corresponds to a single domain of the mammalian sodium channel and that, like potassium channels, four monomers form a tetrameric channel. However, to date, although NaChBac has been well-characterized for functional properties by electrophysiological measurements on protein expressed in tissue culture, little information about its structural properties exists because of the difficulties in expressing the protein in large quantities. In this study, we present studies on the overexpression of NaChBac in Escherichia coli, purification of the functional detergent-solubilized channel, its identification as a tetramer, and characterization of its secondary structure, drug binding, and thermal stability. These studies are correlated with a model produced for the protein and provide new insights into the structure-function relationships of this sodium channel. PMID:18620425

A detailed understanding of the relationship between the underlying molecular structure, the thermodynamics of silicate melts and their phase solubilities is essential in predicting chemical durability and physical properties of glasses. In this work, we present an integrated theory of silicate melts that combines oxide chemistry, silicate speciation, solution thermodynamics and network structure into a statistical thermodynamics approach which describes high temperature phase behavior in terms of silicate speciation. This speciation, in turn, provides both a short and long range description of silicate glass and melt structure which can explain such diverse properties as the chemical durability of a glass and the limits of glass formation in a system. The theory predicts multiple phase behavior that includes the presence of a pair of two-phase equilibrium curves in a single binary system, three phase equilibrium, and a nonsymmetric tricritical point.

The ternary chalcogenide of Cu{sub 3}SbSe{sub 4} is demonstrated to be a novel p-type thermoelectric material, by doping Sn in the Sb site. The figure of merit (ZT) in Cu{sub 3}Sb{sub 0.975}Sn{sub 0.025}Se{sub 4} reaches 0.75 at 673 K. Such excellent thermoelectric properties are attributed to the crystal structure of Cu{sub 3}SbSe{sub 4}, consisting of the three-dimensional Cu/Se framework ({sup 3}{sub {infinity}}[Cu{sub 3}Se{sub 4}]) acting as the hole conduction pathway and the [SbSe{sub 4}] tetrahedra. The Cu/Se framework is suitable to tune the electrical conductivity by doping. The insertion of tetrahedral [SbSe{sub 4}] causes a more distorted diamond-like structure, providing a relatively lower lattice thermal conductivity and a relatively large Seebeck coefficient. The origin of the structure-electrical property relationship and ZT enhancement by Sn doping is elucidated.

This study describes the viscoelastic properties of a refined cellular-tensegrity model composed of six rigid bars connected to a continuous network of 24 viscoelastic pre-stretched cables (Voigt bodies) in order to analyse the role of the cytoskeleton spatial rearrangement on the viscoelastic response of living adherent cells. This structural contribution was determined from the relationships between the global viscoelastic properties of the tensegrity model, i.e., normalized viscosity modulus (eta(*)), normalized elasticity modulus (E(*)), and the physical properties of the constitutive elements, i.e., their normalized length (L(*)) and normalized initial internal tension (T(*)). We used a numerical method to simulate the deformation of the structure in response to different types of loading, while varying by several orders of magnitude L(*) and T(*). The numerical results obtained reveal that eta(*) remains almost independent of changes in T(*) (eta(*) proportional, variant T(*+0.1)), whereas E(*) increases with approximately the square root of the internal tension T(*) (from E(*) proportional, variant T(*+0.3) to E(*) proportional, variant T(*+0.7)). Moreover, structural viscosity eta(*) and elasticity E(*) are both inversely proportional to the square of the size of the structure (eta(*) proportional, variant L(*-2) and E(*) proportional, variant L(*-2)). These structural properties appear consistent with cytoskeleton (CSK) mechanical properties measured experimentally by various methods which are specific to the CSK micromanipulation in living adherent cells. Present results suggest, for the first time, that the effect of structural rearrangement of CSK elements on global CSK behavior is characterized by a faster cellular mechanical response relatively to the CSK element response, which thus contributes to the solidification process observed in adherent cells. In extending to the viscoelastic properties the analysis of the mechanical response of the cellular 30-element tensegrity model, the present study contributes to the understanding of recent results on the cellular-dynamic response and allows to reunify the scattered data reported for the viscoelastic properties of living adherent cells. PMID:12381289

In this paper we investigate the relationship between molecular structure of alkali metal vanillate molecules and their antimicrobial activity. To this end FT-IR, FT-Raman, UV absorption and (1)H, (13)C NMR spectra for lithium, sodium, potassium, rubidium and caesium vanillates in solid state were registered, assigned and analyzed. Microbial activity of studied compounds was tested against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Proteus vulgaris, Bacillus subtilis and Candida albicans. In order to evaluate the dependence between chemical structure and biological activity of alkali metal vanillates the statistical analysis was performed for selected wavenumbers from FT-IR spectra and parameters describing microbial activity of vanillates. The geometrical structures of the compounds studied were optimized and the structural characteristics were determined by density functional theory (DFT) using at B3LYP method with 6-311++G** as basis set. The obtained statistical equations show the existence of correlation between molecular structure of vanillates and their biological properties. PMID:22341494

We report a structure-property relationship in gold nanoparticles (NPs), grain-size effects, which not only allow material properties observed on different characteristic length scales to be engineered in a single NP but further enhance those properties due to the coupling among different-size grains. The grain size effects were achieved by creating polycrystalline gold NPs (pAuNPs) with two distinct grain-size populations (5 and 1 nm) comparable to electron mean free path and electron Fermi wavelength (EFW), respectively. Successful integration of molecular and plasmonic properties into a single nanostructure without additional fluorophores enables these highly polycrystalline AuNPs to serve as multimodal probes in a variety of optical microscopic imaging techniques.We report a structure-property relationship in gold nanoparticles (NPs), grain-size effects, which not only allow material properties observed on different characteristic length scales to be engineered in a single NP but further enhance those properties due to the coupling among different-size grains. The grain size effects were achieved by creating polycrystalline gold NPs (pAuNPs) with two distinct grain-size populations (5 and 1 nm) comparable to electron mean free path and electron Fermi wavelength (EFW), respectively. Successful integration of molecular and plasmonic properties into a single nanostructure without additional fluorophores enables these highly polycrystalline AuNPs to serve as multimodal probes in a variety of optical microscopic imaging techniques. Electronic supplementary information (ESI) available: Figures of DLS, SAED, dark field image, fluorescence image, Raman image, SERS spectra, control cell experiments etc. See DOI: 10.1039/c2nr30212h

The interactions between polyphenols, especially flavonoids and plasma proteins, have attracted great interest among researchers. Few papers, however, have focused on the structure-affinity relationship of polyphenols on their affinities for plasma proteins. The aim of this review is to give an overview of the research reports on the characterization, influence on the bioactivity, and the structure-affinity relationship for studying the affinities between polyphenols and plasma proteins. The molecular properties that influence the affinities of polyphenols for plasma proteins are the following: 1) One or more hydroxyl groups in the B-ring (e.g., 3',4' dihydroxylated B ring catechol group) of flavonoids enhanced the binding affinities to proteins. However, the hydroxyl group in the C-ring w...

Quantitative Structure-Activity Relationship (QSAR) paradigm has proved to be useful in understanding the requirements of physicochemical properties of the molecular substituents in many key locations as well as molecules as a whole. The knowledge of Structure-Activity Relationship (SAR), together with the generation of QSAR, constitutes a large body of evidence that may assist in the development of new molecules with excellent biological activity and low toxicity. The camptothecin (CPT) analogues are emerging as a promising group of chemotherapeutic agents. The SAR of these molecules provide insight into the mechanism of topoisomerase I inhibition and help in the synthesis of various CPT analogues by modifying the different rings of the original CPT molecule, giving each analogue a unique...

An approach to the interpretation of backpropagation neural network models for quantitative structure-activity and structure-property relationships (QSAR/QSPR) studies is proposed. The method is based on analyzing the first and second moments of distribution of the values of the first and the second partial derivatives of neural network outputs with respect to inputs calculated at data points. The use of such statistics makes it possible not only to obtain actually the same characteristics as for the case of traditional "interpretable" statistical methods, such as the linear regression analysis, but also to reveal important additional information regarding the non-linear character of QSAR/QSPR relationships. The approach is illustrated by an example of interpreting a backpropagation neural network model for predicting position of the long-wave absorption band of cyane dyes. PMID:12074390

The well-known Unified Modeling Language (UML) describes software entities, such as interfaces, classes, operations and attributes, as well as relationships among them, e.g. inheritance, containment and dependency. The power of UML lies in Computer Aided Software Engineering (CASE) tools such as Rational Rose, which are also capable of generating software structures from visual object definitions and relations. UML also allows add-ons that define specific structures and patterns in order to steer and automate the design process. We have developed an add-on called Control System Modeling Language (CSML). It introduces entities and relationships that we know from control systems, such as "property" representing a single controllable point/channel, or an "event" specifying that a device is capable of notifying its clients through events. Entities can also possess CSML-specific characteristics, such as physical units and valid ranges for input parameters. CSML is independent of any specific language or technology...

The review discusses recent attempts to elucidate the phycobilisome and phycobiliprotein structures, chromatic adaptation, phycobiliprotein synthesis, chromophore structure and evolutionary relationships of red algae and cyanobacteria. (JMT)

Structure property relationships of noble metal nanoparticles (NPs) can be drastically different than bulk properties of the same metals. This research study used state-of-the-art analytical electron microscopy and scanned probe microscopy to determine material properties on the nanoscale of bio-related Au and Pd NPs. Recently, it has been demonstrated the self-assembly of Au NPs on functionalized silica surfaces creates a conductive surface. Determination of the aggregate morphology responsible for electron conduction was studied by atomic force microscopy (AFM) and scanning electron microscopy (SEM). In addition, changes in the electrical properties of the substrates after low temperature (EELS) spectrum imaging determined optoelectronic properties and chemical composition of the silica shell used to encapsulate Au NPs. Results indicated the sol-gel deposited SiO2 had a band gap energy of ˜8.9eV, bulk plasmon-peak energy of ˜25.5eV and chemical composition of stoichiometric SiO2. Lastly, an attempt to elicit structure property relationships of novel RNA mediated Pd hexagon NPs was performed. Selected area electron diffraction (SAD), low voltage scanning transmission electron microscopy (LV-STEM), electron energy loss spectroscopy (EELS) and energy dispersive spectroscopy (EDS) were chosen for characterization of atomic ordering, chemical composition and optoelectronic properties of the novel nanostructures. Data from control experiments found the hexagons could be made without RNA and confirmed the presence of nanocrystalline Pd metal NPs in unpurified Pd2(DBA)3 reagent powder. Furthermore, the study determined the hexagon platelets to have a chemical composition of ˜90at% carbon and ˜10at% Pd and a lattice parameter corresponding to molecular crystals of Pd2(DBA)3 precursor, not Pd metal.* *This dissertation is a compound document (contains both a paper copy and a CD as part of the dissertation). The CD requires the following system requirements: Windows MediaPlayer or RealPlayer.

Fatigue damage causes continuous, cumulative microstructural changes in materials and the magnetic properties of steels are sensitive to these microstructural changes. The work therefore focused on the relationship between fatigue damage and the measured magnetic properties of different steels under a variety of fatigue conditions. The project also investigated the feasibility and applicability of magnetic inspection techniques for non-destructive evaluation of fatigue damage. From the results of a series of fatigue tests, conducted on different steels under both low-cycle and high-cycle fatigue conditions, the magnetic properties, such as coercivity, remanence and Barkhausen effect, were found to change systematically with fatigue damage. The magnetic properties showed significant changes, especially during early stage of the fatigue and also at the end of the fatigue lifetime. An approximately linear relationship between the mechanical modulus and magnetic remanence was observed and was explained by a model developed in this study to describe the dynamic changes in magnetic and mechanical properties. The results of this research demonstrated that magnetic measurements are suitable for non-destructive evaluation of fatigue damage in steels such as A533B steel and Cr-Mo steels. The magnetic measurement techniques have been incorporated into instrumentation for in-situ evaluation of steel structures and components.

The present study reports (a) the determination of both the kinetic rate constants and equilibrium constants for the reaction of CO2(aq) with sterically-hindered amines and (b) an attempt to elucidate a fundamental chemical understanding of the relationship between the amine structure and chemical properties of the amine that are relevant for post-combustion capture of CO2 (PCC) applications. The reactions of CO2(aq) with a series of linear and methylated primary amines and alkanolamines has been investigated using stopped-flow spectrophotometry and 1H-NMR measurements at 25.0 oC. The specific mechanism of absorption for each of the amines, that is CO2 hydration and/or carbamate formation, is examined and, based on the mechanism, the kinetic and equilibrium constants for the formation of carbamic acid/carbamates, including protonation constants of the carbamate, are reported for amines that follow this pathway. A Brønsted correlation relating the kinetic rate constants and equilibrium constants for the formation of carbamic acid/carbamates with the protonation constant of the amine is reported. Such a relationship facilites an understanding of the effects of steric and electronic properties of the amine towards its reactivity with CO2. Further, such relationships can be used to guide the design of new amines with improved properties relevant to PCC applications. PMID:23190202

The relationships between functional activation patterns and the structural properties of brain pathways have not been widely studied. The recently developed magnetic resonance imaging technique of diffusion tensor imaging (DTI) allows a full characterization of water molecule mobility in three dimensions, providing new structural information that is not available from other in vivo imaging techniques. The directional bias of diffusion (anisotropy) may be derived from the diffusion tensor, and is related to fiber tract integrity and orientation. Since DTI and functional magnetic resonance imaging (fMRI) both require rapid (generally echoplanar) imaging it is possible to obtain geometrically matched images from the two modalities. fMRI and DTI were combined in a visual system study using photic stimulation to demonstrate the feasibility of combining the two methods and to investigate the structural properties of activated regions compared to the white matter tracts. Blood oxygenation level-dependent (BOLD) fMRI activation maps were directly overlayed upon fractional anisotropy (FA) maps, avoiding registration and spatial transformation by carefully matching acquisition parameters. Activated regions had lower FA than optic radiation white matter, supporting the hypothesis that most BOLD signal change occurs within the relatively isotropic cortical grey matter. The combination of these modalities in future studies may provide further insights into relationships between brain structure and function in both health and disease. PMID:10075905

CdSe nanoclusters are created in MgO by means of co-implantation of 280 keV, 1×1016 Cd ions cm-2 and 210 keV, 1×1016 Se ions cm-2 in single crystals of MgO(001) and subsequent thermal annealing at a temperature of 1300 K. The structural properties and the orientation relationship between the CdSe and the MgO are investigated using cross-sectional transmission electron microscopy (XTEM). The crystal structure of the nanoclusters depends on their size. The smallest nanoclusters with a size below 5 nm have the cubic rocksalt crystal structure. The larger nanoclusters have a different (most likely the cubic sphalerite) crystal structure. The defect evolution in the sample after ion implantation and during thermal annealing is investigated using Doppler broadening positron beam analysis (PBA). The defect evolution in samples co-implanted with Cd and Se is compared to the defect evolution in samples implanted with only Cd or only Se ions.

Parents and caregivers faced with the challenges of transferring children with disability are at risk of musculoskeletal injuries and/or emotional stress. The Caregiver Self-Efficacy Scale for Transfers (CSEST) is a 14-item questionnaire that measures self-efficacy for transferring under common conditions. The CSEST yields reliable data and valid inferences; however, its rating scale structure has not been evaluated for utility. The aims of this study were to evaluate the category response structure of the CSEST, test the utility of a revised rating scale structure, and confirm its psychometric properties. The Rasch Measurement Model was used for all analyses. Subjects included 175 adult caregivers recruited from multiple communities. Results confirm that a revised five-category rating scale structure yields reliable data and valid inferences. Given the relationship between self-efficacy and risk of physical and/or emotional stress, measuring parental self-efficacy for transfers is a proactive process in rehabilitation. (Contains 5 tables and 1 figure.)

Physics of layered systems is studied from the crystal structure point of view. The relationships between structural and superconducting properties are discussed, and particular attention is paid to the layered structure. We discuss the possible role of inequivalent layers and charge transfer interlayer redistribution. By taking into account the modified charge transfer approach a workable model that provides a possibility for comparison of the structural, electronic, chemical factors etc., for the occurrence of superconductivity of layered systems is considered. The present paper analyzes the possible applications of the inequivalent layer model to the mercurocuprate family and provides rationalization to the experimentally observed nonmonotonic 'bell'-shaped dependence of critical temperature of a number of layers in the elementary cell.

Further improvement of electrical properties and thermal stability of reactively sputtered refractory metal nitride contacts on GaAs and In-based ohmic contacts to GaAs require a systematic study of the relationships between structural and electrical characteristics at the interface. In this study, the interface morphologies and structures of Nb/GaAs, NbN/GaAs, TiN/GaAs, WN/GaAs and In/GaAs contacts have been investigated before and after annealing at temperatures up to 950{degrees}C by transmission electron microscopy and diffraction, energy dispersive spectrometry of x-rays, x-ray diffractometry and cross-sectional high resolution transmission electron microscopy. The results from these techniques were combined to provide detailed descriptions of the structural evolution of the interface region in refractory metal nitride/GaAs and In/GaAs heterojunctions. Structural details were related to the corresponding electrical characteristics. 145 refs., 44 figs.

In recent years considerable attention has been given to methods for modifying and controlling the electronic and quantum mechanical properties of graphene quantum dots. However, as these types of properties are indirect consequences of the wavefunction of the material, a more efficient way of determining properties may be to engineer the wavefunction directly. One way of doing this may be via deliberate structural modifications, such as producing graphene nanostructures with specific sizes and shapes. In this paper we use quantum mechanical simulations to determine whether the wavefunction, quantified via the distribution of the highest occupied molecular orbital, has a direct and reliable relationship to the physical structure, and whether structural modifications can be useful for wavefunction engineering. We find that the wavefunction of small molecular graphene structures can be different from those of larger nanoscale counterparts, and the distribution of the highest occupied molecular orbital is strongly affected by the geometric shape (but only weakly by edge and corner terminations). This indicates that both size and shape may be more useful parameters in determining quantum mechanical and electronic properties, which should then be reasonably robust against variations in the chemical passivation or functionalisation around the circumference. PMID:22903345

In order to gain an insight into the relationship between the molecular structure and the semiconductor characteristics of highly ?-extended heteroarene-based organic semiconductors, three structural isomers of dinaphthothieno[3,2-b]thiophenes with C2h symmetry were investigated. Of these, two isomers, dinaphtho[2,1-b:2?,1?-f ]thieno[3,2-b]thiophene (2) and dinaphtho[1,2-b:1?,2?-f ]thieno[3,2-b]thiophene (3), were newly synthesized, characterized, and utilized as active semiconducting layers in organic field-effect transistors (FETs). Detailed investigation of the physicochemical properties of 2 and 3, together with another isomer, dinaphtho[2,3-b:2?,3?-f ]thieno[3,2-b]thiophene (1), indicated that the electronic structures of the three isomers are fairly different from each other despite having the same molecular formula and the same aromatic constituents. Comparison of the molecular arrangements in the crystals elucidated by X-ray structural analysis implied that the molecular shape and the thus-induced favorable intermolecular interactions play important roles in determining the entire molecular arrangement. The characteristics of 2- and 3-based FETs with maximum field-effect mobilities (?FET s) of 10?3–10?2 cm2 V?1 s?1 were inferior to those of 1-based FETs with ?FET s up to 3.0 cm2 V?1 s?1. The inferior characteristics of 2- and 3-based devices were due to film morphology as elucidated by atomic force microscopy (AFM) and supported by theoretical calculations of electronic structure in the solid state. Together, the results indicate that the molecular structure and shape, even for similar heteroarenes with the same molecular formula and symmetry, are important parameters to determine the solid-state properties of organic semiconductors. Three structural isomers of dinaphthothieno[3,2-b]thiophenes with C2h symmetry were investigated to gain an insight into the relationship between the molecular structure and the semiconductor characteristics of highly ?-extended heteroarene-based organic semiconductors.   Fullsize Image

A variety of consumable plant-derived phytochemicals exhibit nutraceutical properties because they produce physiological benefits and combat disease processes. Emerging evidence suggests that widely accessible and safe organic polyphenolic phytochemicals, in particular, treat depression at much lower concentrations than clinical doses of classical drugs. Structurally similar polyphenolics such as curcumin, resveratrol, and proanthocyanidins exhibit antioxidant and immunomodulatory properties and recent research suggests that they also modulate hypothalamic-pituitary-adrenal (HPA) axis activity, serotonergic transmission and hippocampal neurogenesis (perhaps via their effects on serotonin and HPA activity). These data tempt speculation that polyphenolic compounds could also combat age-related cognitive decline, which is often accompanied by depression and potentially by reduced levels of hippocampal neurogenesis. Here we review the relationships between dysregulation of these systems and age-related cognitive decline. We then suggest that this group of structurally similar polyphenolic compounds may be particularly promising therapeutic leads for age-related cognitive decline and depression because they modulate these processes. PMID:22947921

In order to understand the relationship between chemical structure and physical properties of cereal @b-glucans, the @b-glucans with identical M"w (98.4-99.2kDa) and R"g (21.1-22.0nm) were isolated from chal and gwangan barley, and ohl oat, and their linkage structure, flow behavior, and thermal properties were investigated. Previously, we established a purification method of 3-O-cellobiosyl-glucose (DP3) and 3-O-cellotriosyl-glucose (DP4) (Yoo, Lee, Chang, Lee, & Yoo, 2007) and applied these authentic standards to quantify the ratio of @b-(1,4)/(1,3) linkages in cereal @b-glucans. @b-Glucans isolated from two barley cultivars had greater proportion of DP3 than did the oat, and within barley cultivars chal barley @b-glucan had significantly larger amount of DP3 over gwangan cultivar. Thus,...

Many transport processes on networks depend crucially on the underlying network geometry, although the exact relationship between the structure of the network and the properties of transport processes remain elusive. In this paper we address this question by using numerical models in which both structure and dynamics are controlled systematically. We consider the traffic of information packets that include driving, searching and queuing. We present the results of extensive simulations on two classes of networks; a correlated cyclic scale-free network and an uncorrelated homogeneous weakly clustered network. By measuring different dynamical variables in the free flow regime we show how the global statistical properties of the transport are related to the temporal fluctuations at individual nodes (the traffic noise) and the links (the traffic flow). We then demonstrate that these two network classes appear as representative topologies for optimal traffic flow in the regimes of low density and high density traff...

Spider dragline silk possesses impressive mechanical and biochemical properties. It is synthesized by a couple of major ampullate glands in spiders and comprises of two major structural proteins?spidroins 1 and 2. The relationship between structure and mechanical properties of spider silk is not well understood. Here, we modeled the complete process of the spider silk assembly using two new recombinant analogs of spidroins 1 and 2. The artificial genes sequence of the hydrophobic core regions of spidroin 1 and 2 have been designed using computer analysis of existing databases and mathematical modeling. Both proteins were expressed in Pichia pastoris and purified using a cation exchange chromatography. Despite the absence of hydrophilic N- and C-termini, both purified proteins spontaneously...

Fabrication and development of TiB2-based nanostructured coatings was investigated in the present work. By varying the sputter-target power density, substrate temperature, deposition time, substrate-to-target distance, substrate biasing and substrate sputter cleaning, the relationship between the sputtered structure, properties and sputtering conditions were established. The experimental results showed that the target-to-substrate distance played a major role in the coating structure and properties. Sputter cleaning of substrate helped to improve TiB2 coating hardness and adhesion. The deposition process could be controlled to produce a TiB2 coating with both high hardness and good adhesion strength. This was achieved by introducing substrate sputter-cleaning and then biasing for the early stage of deposition, followed by deposition without biasing.   

A new synthesis route to prepare magnetite nanoparticles in only one step is described. The precipitation of magnetite is performed in the presence of aminoacid solution. The experimental protocol is original and the nanomagnetites are characterized by XRD, FTIR, TEM and SQUID magnetometry. A theoretical study of the consistent experimental results was performed using QSPR (Quantitative Structure Property Relationsheep). According with these studies the synthesized nanoparticles seem to be organized into a core-shell system, where the inner-core is formed from unit cells of magnetite. A way to control the self-assembly and the physical properties of the synthesized nanoparticles consists in their correlation with descriptors representing the aminoacid chemical structures. Using quantum chemical as well as the other simplest original descriptors it was found a relationship between the used aminoacids and the magnetization, nanoparticles diameter, magnetite core diameter and the (Fe{sub 3}O{sub 4}){sub 8} cells in each nanoparticle core.

The relationship between Lexical-Functional Grammar (LFG) functional structures (f-structures) for sentences and their semantic interpretations can be expressed directly in a fragment of linear logic in a way that explains correctly the constrained interactions between quantifier scope ambiguity and bound anaphora. The use of a deductive framework to account for the compositional properties of quantifying expressions in natural language obviates the need for additional mechanisms, such as Cooper storage, to represent the different scopes that a quantifier might take. Instead, the semantic contribution of a quantifier is recorded as an ordinary logical formula, one whose use in a proof will establish the scope of the quantifier. The properties of linear logic ensure that each quantifier is scoped exactly once. Our analysis of quantifier scope can be seen as a recasting of Pereira's analysis (Pereira, 1991), which was expressed in higher-order intuitionistic logic. But our use of LFG and linear logic provides a...

According to the coupling relationship of electromagnetic field, thermal field and acoustic field during the time that microwave irradiates the biological tissues, we conducted a study on the microwave-induced thermoacoustic tomography forward problem. In the study, we started from the thermoacoustic wave propagation that incorporated the spatial inhomogeneities of thermal and acoustic properties, and we used a method based on the finite element to solve the thermoacoustic equation. As the penetration depth and the specific absorption rate changed with the microwave frequency in biological tissue, the hotspot position and value altered, so the pressure wave propagation and the detecting value would be influenced. By analyzing the simulation results, we found that different detection point has different information content. Because the microwave-induced acoustic waves contain abundant information about the structural, electromagnetic and acoustic properties of phantom, they can reflect information on the tissue composition and structure of the phantom effectively. PMID:18435254

The morphology, crystalline structure of epitaxial heterostructures of Pb(Zr0.52Ti0.48)O3/La0.7Sr0.3MnO3 (PZT/LSMO) grown on single crystalline SrTiO3 substrates by pulse laser deposition (PLD), have been investigated. The morphology results show that the LSMO layers and PZT layers are smooth and homogenous. The crystalline structure measurements indicate that good epitaxial relationships between LSMO and PZT and STO were obtained. The effects of applied electric and magnetic fields on the physical properties of epitaxial perovskite ferroelectric/ferromagnetic heterostructures were investigated. The results show that the polarized electric field has a very significant influence on the transport properties of LSMO layers while has little influence on the magnetization, and the magnetic field has an obvious influence on the ferroelectric behavior of the PZT layer.

For the first time, thin-film libraries of zinc(II) bis-2,2':6',2"-terpyridine metallopolymers are prepared by inkjet printing to study structure-property relationships and their possible usage for organic photovoltaic (OPV) or polymer light-emitting diode (PLED) applications. By using a combinatorial approach, various important parameters, including solvent system, dot spacing, and substrate temperature, as well as UV-vis absorption and emission properties, are screened in a materials efficient and reproducible manner. Homogeneous films with a thickness of 150 -200 nm were obtained when printed at 40 -50 °C and from a solvent mixture of N,N-dimethylformamide and acetophenone in a ratio of 90/10. In applications such as OPV and PLEDs the control over film thickness and homogeneity are central to obtain good device properties. PMID:22290829

White and fluffy Al-doped zinc oxide powders were fabricated using ZnO and Al(C3H7O)3 powders by a solid state method. The effects of Al doping on microstructure, electrical and optical properties were systematically studied. XRD and Raman results show that the Al-doped powders have a pure hexagonal wurtzite structure. The resistivity of ZnO could be decreased from 108 to 102 ? cm with the Al doped concentration of 3 at.%. Meanwhile, the obtained powders exhibited high diffuse reflectance in visible region, intense UV emission without deep level emission and good environmental stability. Results reveal that the optical property of the powders has an intimate relationship with the electrical property. The decline of the diffuse reflectance at visible wavelengths and the strong IR absorption...

Motivated by an improved understanding of skeletal fragility, the objective of this study was to investigate the relationships between morphological and mechanical properties of bone structural units (BSU). The average orientation of collagen fibers was classified using polarized light microscopy (PLM) and the mean degree of mineralization (MDMB) was quantified by microradiography for a collection of BSU from two donors. The mechanical properties of the same BSU were then measured by nanoindentation and scanning acoustic microscopy (SAM). Surprisingly, the indentation modulus and hardness quantified by nanoindentation were only weakly correlated to MDMB. The longitudinal wave modulus measured by SAM was better related to MDMB but did not correlate with the indentation modulus. There is increasing evidence that the collagenous phase and its bonding to the mineral phase play a significant role in the mechanical properties of bone tissue and deserve more attention in our understanding of bone fragility.

Zirconium oxide is one of the most extensively studied transition-metal oxides for its several attractive properties and the variety of its technological applications. Research was especially stimulated in understanding the factors controlling the structure of ZrO2 and in identifying the relationship between bulk and surface properties of ZrO2 thin films. In the present work, ZrO2 thin films were deposited on Si, without external heating, by RF reactive sputtering from a pure ZrO2 target in Ar/O2 plasma with different O2 concentrations (0?20%). Aim of the study was the identification of the effects of the processing parameters ? mainly the O2/Ar ratio in the gas phase ? on the film growth and properties. The addition of O2 was crucial to establish a good stoichiometry, as revealed by Auger...

In Europe, ethyl tert-butyl ether (ETBE) is currently considered as one of the most promising bio-fuels when it is obtained from bio-ethanol. Nevertheless, its industrial synthesis process leads to an azeotropic mixture containing 20wt% of ethanol which has to be removed for fuel applications. In this work, new graft copolymers cellulose acetate-g-poly(methyl diethylene glycol methacrylate) are considered for the purification of ETBE by pervaporation. Two families of graft copolymers were investigated with almost the same copolymer graft contents but short or long highly permeable grafts. Their properties are discussed in terms of structure-property relationships for the sorption and pervaporation of the targeted azeotropic mixture. It is shown that the sorption properties are mainly gover...

This research is focused on the synthesis of new iron-rare-earth magnetic phases which may have significant technological properties. An important aim is to investigate new methods for producing these materials such as melt spinning and sputtering plus specific heat treatments. Studies are made of the relationship between microstructure and properties such as coercivity, spontaneous magnetization, and anisotropy (magnitude and direction) in bulk and thin film samples. Our goal is to understand these relatively complex materials on the basis of fundamental electronic structure, theory is of itinerant magnetism and localized 4f electronic states, and the microstructural effects which control the extrinsic properties. To achieve this a broad range of experiments and calculations are performed. In the following we describe briefly some of our recent accomplishments, with emphasis on work performed in the last six months.

Abstract in english Carbon Fibre Reinforced Carbon (CFRC) Composites are increasing their applications due to their high strength and Young?s Modulus at high temperatures in inert atmosphere. Although much work has been done on processing and structure and properties relationship, few studies have addressed the modelling of mechanical properties. This work is divided in two parts. In the first part, a modelling of mechanical properties was carried out for two bi-directional composites using (more) a model based on the Bernoulli-Euler theory for symmetric laminated beams. In the second part, acoustic emission (AE) was used as an auxiliary technique for monitoring the failure process of the composites. Differences in fracture behaviour are reflected in patterns of AE.

The relationship between the structures and photoelectrochemical properties of two dyes, cis-dithiocyanato-N,N'-bis(4,4'-dicarboxyl-2,2'-bipyridyl) Ru(II) and cis-dithiocyanato-(4,4'-dicarboxyl-2,2'-bipyridyl)-(4,4'-di((N,N'-methylphenyl= amino)methylene)-2,2'-bipyridyl) Ru(II), was examined and compared under the same conditions. Data show that the photophysical properties (including molar extinction coefficients {epsilon} and excited-state lifetimes) and photoelectrochemical properties (including short-circuit photocurrent, open-circuit photovoltage, incident monochromatic photon to current conversion efficiency, overall energy conversion yield ({eta}) and transient photocurrent) were changed greatly only due to an acceptor replaced by a donor in one of polypyridyl of the Ru(II) complex, suggesting that the molecular design in energy conversion is very sensitive.

We develop novel calculation and analysis methods for the dynamic first hyperpolarizabilities ? [the second-order nonlinear optical (NLO) properties at the molecular level] in the second-harmonic generation based on the quantum master equation method combined with the ab initio molecular orbital (MO) configuration interaction method. As examples, we have evaluated off-resonant dynamic ? values of donor (NH(2))- and/or acceptor (NO(2))-substituted benzenes using these methods, which are shown to reproduce those by the conventional summation-over-states method well. The spatial contributions of electrons to the dynamic ? of these systems are also analyzed using the dynamic ? density and its partition into the MO contributions. The present results demonstrate the advantage of these methods in unraveling the mechanism of dynamic NLO properties and in building the structure-dynamic NLO property relationships of real molecules. PMID:22468934

Due to recent significant enhancement of computer performance as well as computational techniques, molecular modeling and molecular simulations using computational chemistry can be achieved at the level of practical applications. Even in solvent extraction, the application of computational chemistry to simulations of extraction processes and the molecular design of high-performance extracting agents have gradually been increasing during the last decade. With combining the quantitative structure-property relationship between the molecule properties calculated by the computational chemistry methods and the thermodynamic properties obtained from experiments, researchers can precisely predict the next-generation of extracting agents and novel extraction processes. In this review, the concept of computational chemistry, such as molecular mechanics, molecular orbitals and molecular dynamics calculations, frequently used in the filed of solvent extraction, are outlined. Our systematic research on the solvent-extraction process utilizing MM, MO and MD calculations is also presented.   

The macroscopic properties of many materials are controlled by the structure and chemistry at grain boundaries. A basic understanding of the structure-property relationship requires a technique which probes both composition and chemical bonding on an atomic scale. High-resolution Z-contrast imaging in the scanning transmission electron microscope (STEM) forms an incoherent image in which changes in atomic structure and composition across an interface can be interpreted directly without the need for preconceived atomic structure models. Since the Z-contrast image is formed by electrons scattered through high angles, parallel detection electron energy loss spectroscopy (PEELS) can be used simultaneously to provide complementary chemical information on an atomic scale. The fine structure in the PEEL spectra can be used to investigate the local electronic structure and the nature of the bonding across the interface. In this paper we use the complimentary techniques of high resolution Z-contrast imaging and PEELS to investigate the atomic structure and chemistry of a 25{degree} symmetric tilt boundary in a bicrystal of the electroceramic SrTiO{sub 3}.

Words expressing the idea of ?yes? and ?no? behave differently from language to language. The examples analyzed in this paper show that the Russian net has additional meanings as compared to the German nein (as well as to the English no) because the Russian net is connected with both dictum and modus, i.e. not only with the propositional part of the utterance. Many of the cross-linguistic differences discussed here relate to the specific properties of the discourse structure. Thus, the Russian discourse is characterized by a hypertrophied coherence, addressing various levels of content, and focusing on interpersonal relationships between interlocutors, which they steadily profile in the course of conversation.