New Functionality (new + functionality)

Distribution by Scientific Domains

Selected Abstracts

Medical Potentialities of Biomimetic Apatites through Adsorption, Ionic Substitution, and Mineral/Organic Associations: Three Illustrative Examples,

Ahmed Al-Kattan
Biomimetic calcium phosphate apatites are particularly adapted to bio-medical applications due to their biocompatibility and high surface reactivity. In this contribution we report three selected examples dealing with mineral/organic interactions devoted to convey new functionalities to apatite materials, either in the form of dry bioceramics or of aqueous colloids. We first studied the adsorption of risedronate (bisphosphonate) molecules, which present potential therapeutic properties for the treatment of osteoporosis. We then addressed the preparation of luminescent Eu-doped apatites for exploring apatite/collagen interfaces through the FRET technique, in view of preparing "advanced" biocomposites exhibiting close spatial interaction between apatite crystals and collagen fibers. Finally, we showed the possibility to obtain nanometer-scaled apatite-based colloids, with particle size tailorable in the range 30,100,nm by controlling the agglomeration state of apatite nanocrystals by way of surface functionalization with a phospholipid moiety. This paper is aimed at illustrating some of the numerous potentialities of calcium phosphate apatites in the bio-medical field, allowing one to foresee perspectives lying well beyond bone-related applications. [source]

How Far Are We from Making Metamaterials by Self-Organization?

The Microstructure of Highly Anisotropic Particles with an SRR-Like Geometry
Abstract Metamaterials offer new unusual electromagnetic properties, which have already been demonstrated, and many postulated new functionalities are yet to be realized. Currently, however, metamaterials are mostly limited by narrow band behavior, high losses, and limitation in making genuinely 3D materials. In order to overcome these problems an overlap between metamaterial concepts and materials science is necessary. Engineered self-organization is presented as a future approach to metamaterial manufacturing. Using directional solidification of eutectics, the first experimental realization of self-organized particles with a split-ring resonator-like cross section is demonstrated. This unusual morphology/microstructure of the eutectic composite has a fractal character. With the use of TEM and XRD the clear influence of the atomic crystal arrangement on the microstructure geometry is presented. The materials obtained present very high anisotropy and can be obtained in large pieces. Metallodielectric structures can be created by etching and filling the space with metal. The next steps in the development of self-organized materials exhibiting unusual properties are discussed. [source]

General Synthesis and Aggregation Behaviour of New Single-Chain Bolaphospholipids: Variations in Chain and Headgroup Structures

Simon Drescher
Abstract The chemical structures of polymethylene-1,,-bis(phosphocholines) that self-assemble into nanofibres was modified on the one hand in the hydrophobic chain region, by introduction of sulfur and oxygen atoms, and on the other hand by variation of the polar headgroup structure with functionalised tertiary amines. The temperature-dependent self-assembly of these novel bolaphospholipids into nanofibres and spherical micelles was investigated by differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). The thermal stabilities of the nanofibres strongly depend on the chemical compositions of the headgroups and of the hydrophobic chains. The insertion of new functionalities in the headgroup region by click chemistry makes these substances interesting for potential applications in bioscience and materials science. [source]

Magnonics: Spin Waves on the Nanoscale

Sebastian Neusser
Abstract Magnetic nanostructures have long been in the focus of intense research in the magnetic storage industry. For data storage the nonvolatility of magnetic states is of utmost relevance. As information technology generates the need for higher and higher data-transfer rates, research efforts have moved to understand magnetization dynamics. Here, spin waves and their particle-like analog, magnons, are increasingly attracting interest. High-quality nanopatterned magnetic media now offer new ways to transmit and process information without moving electrical charges. This new functionality is enabled by spin waves. They are confined by novel functioning principles, which render them especially suitable to operate at the nanoscale. Magnonic crystals are expected to provide full control of spin waves, similarly to what photonic crystals already do for light. Combined with nonvolatility, multifunctional metamaterials might be formed. We report recent advances in this rapidly increasing research field called magnonics. [source]

Adaptive repetitive control for resonance cancellation of a distributed solar collector field

J. D. lvarez
Abstract This paper deals with modelling and control of the outlet temperature in a distributed solar collector field. The resonance dynamics characteristics of this kind of system are similar to those of tubular heat exchangers in the closed-loop system bandwidth when fast responses are required. Simple low-order rational models are unable to capture the resonance dynamics, which can be excited by changes in both the heat transfer fluid flow and solar irradiation. This paper proposes a new model derived from a similar model for a tubular heat exchanger. This model allows the use of low-order controllers, which can be extended to an adaptive control scheme to account for varying resonance frequencies, as a new functionality achieving fast, well-damped responses. Copyright 2008 John Wiley & Sons, Ltd. [source]

Generic representation and evaluation of properties as a function of position in reciprocal space

Kevin Cowtan
A generalized approach is described for evaluating arbitrary functions of position in reciprocal space. This is a generalization which subsumes a whole range of calculations that form a part of almost every crystallographic software application. Examples include scaling of structure factors, the calculation of structure-factor statistics, and some simple likelihood calculations for a single parameter. The generalized approach has a number of advantages: all these calculations may now be performed by a single software routine which need only be debugged and optimized once; the existing approach of dividing reciprocal space into resolution shells with discontinuities at the boundaries is no longer necessary; the implementation provided makes employing the new functionality extremely simple and concise. The calculation is split into three standard components, for which a number of implementations are provided for different tasks. A `basis function' describes some function of position in reciprocal space, the shape of which is determined by a small number of parameters. A `target function' describes the property for which a functional representation is required, for example . An `evaluator' takes a basis and target function and optimizes the parameters of the basis function to fit the target function. Ideally the components should be usable in any combination. [source]

Covalent immobilization of ,-galactosidase on carrageenan coated with chitosan

Magdy M.M. Elnashar
Abstract ,-Galactosidase was covalently immobilized to carrageenan coated with chitosan for the hydrolysis of lactose. The chitosan-carrageenan polyelectrolyte interaction was found to be dependent on the chitosan pH. At pH 4, the chitosan reached its maximum binding of 28.5% (w/w) where the chitosan surface density was 4.8 mg chitosan/cm2 g of carrageenan gel disks, using Muzzarelli method. Glutaraldehyde was used as a mediator to incorporate new functionality, aldehydic carbonyl group, to the bio-polymers for covalent attachment of ,-galactosidase. The enzyme was covalently immobilized to the biopolymer at a concentration of 2.73 mg protein per g of wet gel. FTIR proved the incorporation of the aldehydic carbonyl group to the carrageenan coated with chitosan at 1720 cm,1. The optimum time for enzyme immobilization was found to be 16 h, after which a plateau was reached. The enzyme loading increased from 2.65 U/g (control gel) to 10.92 U/g gel using the covalent technique. The gel's modification has shown to improve the carrageenan gel thermal stability as well as the immobilized enzyme. For example, the carrageenan gel treated with chitosan showed an outstanding thermal stability at 95C compared with 35C for the untreated carrageenan gel. Similarly, the immobilization process shifted the enzyme's optimum temperature from 50C for the free enzyme towards a wider temperature range 45,55 C indicating that the enzyme structure is strengthened by immobilization. In brief, the newly developed immobilization method is simple; the carrier is cheap, yet effective and can be used for the immobilization of other enzymes. 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source]

Novel thermally and mechanically stable hydrogel for enzyme immobilization of penicillin G acylase via covalent technique

Magdy M. M. Elnashar
Abstract ,-Carrageenan hydrogel crosslinked with protonated polyethyleneimine (PEI+) and glutaraldehyde (GA) was prepared and evaluated as a novel biocatalytic support for covalent immobilization of penicillin G acylase (PGA). The method of modification of the carrageenan biopolymer is clearly illustrated using a schematic diagram and was verified by FTIR, elemental analysis, DSC, and INSTRON using the compression mode. Results showed that the gels' mechanical strength was greatly enhanced from 3.9 kg/cm2 to 16.8 kg/cm2 with an outstanding improvement in the gels thermal stability. It was proven that, the control gels were completely dissolved at 35C, whereas the modified gels remained intact at 90C. The DSC thermogram revealed a shift in the endothermic band of water from 62 to 93C showing more gel-crosslinking. FTIR revealed the presence of the new functionality, aldehydic carbonyl group, at 1710 cm,1 for covalent PGA immobilization. PGA was successfully immobilized as a model industrial enzyme retaining 71% of its activity. The enzyme loading increased from 2.2 U/g (control gel) to 10 U/g using the covalent technique. The operational stability showed no loss of activity after 20 cycles. The present support could be a good candidate for the immobilization of industrial enzymes rich in amino groups, especially the thermophilic ones. 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]

ForceFit: A code to fit classical force fields to quantum mechanical potential energy surfaces

Benjamin Waldher
Abstract The ForceFit program package has been developed for fitting classical force field parameters based upon a force matching algorithm to quantum mechanical gradients of configurations that span the potential energy surface of the system. The program, which runs under UNIX and is written in C++, is an easy-to-use, nonproprietary platform that enables gradient fitting of a wide variety of functional force field forms to quantum mechanical information obtained from an array of common electronic structure codes. All aspects of the fitting process are run from a graphical user interface, from the parsing of quantum mechanical data, assembling of a potential energy surface database, setting the force field, and variables to be optimized, choosing a molecular mechanics code for comparison to the reference data, and finally, the initiation of a least squares minimization algorithm. Furthermore, the code is based on a modular templated code design that enables the facile addition of new functionality to the program. 2010 Wiley Periodicals, Inc. J Comput Chem, 2010 [source]

Modelling fault-proneness statistically over a sequence of releases: a case study

Magnus C. Ohlsson
Abstract Many of today's software systems evolve through a series of releases that add new functionality and features, in addition to the results of corrective maintenance. As the systems evolve over time it is necessary to keep track of and manage their problematic components. Our focus is to track system evolution and to react before the systems become difficult to maintain. To do the tracking, we use a method based on a selection of statistical techniques. In the case study we report here that had historical data available primarily on corrective maintenance, we apply the method to four releases of a system consisting of 130 components. In each release, components are classified as fault-prone if the number of defect reports written against them are above a certain threshold. The outcome from the case study shows stabilizing principal components over the releases, and classification trees with lower thresholds in their decision nodes. Also, the variables used in the classification trees' decision nodes are related to changes in the same files. The discriminant functions use more variables than the classification trees and are more difficult to interpret. Box plots highlight the findings from the other analyses. The results show that for a context of corrective maintenance, principal components analysis together with classification trees are good descriptors for tracking software evolution. Copyright 2001 John Wiley & Sons, Ltd. [source]

Biodoped Ceramics: Synthesis, Properties, and Applications

Smita Y. Gadre
This feature article focuses on biodoped ceramics. These are inorganic materials in which biological materials are incorporated, thus adding new functionality to them. A brief overview of the prominent synthesis techniques for biodoped ceramics, with emphasis on modified sol,gel processes for metal oxide matrices, is given first. Theoretical treatments of the encapsulation of biologicals within a porous ceramic matrix are reviewed. Experimental studies of the stability and dynamics of protein entrapment in silica and other ceramic matrices are also discussed. Finally, key applications of biodoped ceramics in biochemical species detection, bio-catalysis, and drug delivery are presented. [source]

Proteomics FASTA Archive and Reference Resource

Jayson A. Falkner
Abstract A FASTA file archive and reference resource has been added to Motivation for this new functionality derives from two primary sources. The first is the recent FASTA standardization work done by the Human Proteome Organization's Proteomics Standards Initiative (HUPO-PSI). Second is the general lack of a uniform mechanism to properly cite FASTA files used in a study, and to publicly access such FASTA files post-publication. An extension to the Tranche data sharing network has been developed that includes web-pages, documentation, and tools for facilitating the use of FASTA files. These include conversion to the new HUPO-PSI format, and provisions for both citing and publicly archiving FASTA files. This new resource is available immediately, free of charge, and can be accessed at Source-code for related tools is also freely available under the BSD license. [source]

Commercializing new technologies: consumers' response to a new interface

Paschalina (Lilia) Ziamou
Successful commercialization of new technologies is the riskiest and most rewarding form of new product development activity. New technologies are often commercialized using innovative interfaces that determine how consumers interact with a new product to obtain its functionality. Consumers' perception of uncertainty about the performance of a novel interface is a key issue in the acceptance of new products involving new interfaces. Specifically, when firms commercialize a new interface, they face two major challenges: First to identify the optimal functionality for the new interface, and second, to effectively communicate with consumers in order to reduce uncertainty about the performance of the new interface and increase adoption intentions. Despite the theoretical and managerial importance of research on consumers' response to a novel interface, very little empirical research has been conducted in this area. Building on prior research on new product development, human-computer interaction, and consumer decision-making, this article examines the factors that influence consumers' judgments of uncertainty about the performance of a new interface and consumers' adoption intentions. Specifically, we conducted an experiment to investigate the effect of the newness of the functionality of a new product and the effect of imagery on consumers' uncertainty about the performance of a novel interface and consumers' adoption intentions. Our results show that consumers perceive lower uncertainty about the performance of a new interface and higher intentions to adopt a new product when the new interface is introduced with a new (vs. pre-existing) functionality. Furthermore, our results suggest that when a new interface is introduced with a new functionality, imagining the product in use increases consumers' uncertainty about the performance of the new interface and decreases their intention to adopt the new product. In contrast, when a new interface is introduced with a pre-existing functionality, imagining the product in use decreases consumers' uncertainty about the performance of the new interface and increases their intention to adopt the new product. Our findings provide valuable guidelines for marketers in formulating new product development and communication strategies for new products involving a new interface. 2002 Elsevier Science Inc. All rights reserved. [source]