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Desired Properties (desired + property)
Selected AbstractsTailoring Materials Properties by Accumulative Roll Bonding,ADVANCED ENGINEERING MATERIALS, Issue 8 2010Tina Hausöl Accumulative roll bonding (ARB) as a method of severe plastic deformation (SPD) is an interesting established process to produce ultrafine-grained (UFG) sheet materials with high potential for light weight constructions. The ARB process offers a high flexibility for tailored material design. Al2O3 particles, carbon fibers and titanium foils are used as reinforcement of aluminum sheets introduced during accumulative roll bonding. Furthermore multicomponent materials are produced by cladding of different aluminum alloys. These sandwich-like structures allow to combine desired properties of the materials involved. Post-ARB heat treatment offers another possibility for tailoring materials properties of graded structures as shown by formation of TiAl3 in Al/Ti laminates. The tailored materials are investigated by means of SEM, EDX, nanoindentation experiments and tensile testing. [source] Sol,Gel Derived Nanocomposites for Optical ApplicationsADVANCED ENGINEERING MATERIALS, Issue 5 2010Peter W. de Oliveira This paper provides a selective description of the development of nanostructured materials and the fabrication of the devices for optical applications. Examples are interference coatings, refractive and diffractive lenses, and macro- and micro-GRIN (graded refractive index) optical elements. Hybrid materials containing nanoparticles are of particular interest for the production of optical elements because, by exploiting the intrinsic solid state properties of the nanoparticles, nanocomposites can be tailored to exhibit the desired properties. A particular advantage of wet chemical processing lies in its great flexibility for depositing functional coatings. [source] Colours and Metallic Sheen in Beetle Shells , A Biomimetic Search for Material Structuring Principles Causing Light Interference,ADVANCED ENGINEERING MATERIALS, Issue 4 2008T. Lenau Abstract Visual aesthetic has always played a vital role for the success of many products. This includes colours and glossiness and metal appearance which is often achieved using surface coatings. Present coating techniques do, however, have limitations. It is difficult to reach very bright and brilliant colours, colours tend to fade over time and many of the materials and coating technologies pollute and have other environmental problems. Beetles in nature have many of the desired properties: They have appealing brilliant colours and some even with metallic appearance. It is noticeable that the colours are long lasting as some of the beetles we have studied at the zoological museum are more than 200 years old and have colours and brightness as if they were still alive. Furthermore, the beetles in nature are part of sustainable ecosystems, which means that they are made from renewable materials that are broken down and recycled when the beetle dies. Beetles also possess another and very attractive property: Their metallic look originates from structures in organic materials which is both electrically and thermal insulating. The industrial perspective is to be able to manufacture products with attractive metallic surfaces that do not feel so cold to touch as their metallic counterparts and that do not represent an electrical shock hazard. [source] Characterisation and Modelling of Non-Isothermal Precipitation in Metallic Systems,ADVANCED ENGINEERING MATERIALS, Issue 12 2006A. Deschamps During the process of most age hardening metallic alloys, non-isothermal precipitation plays a key role. The non-isothermal nature of precipitation processes can be either imposed by constraints of the process route (e.g. precipitation during coiling of NbC in steels, or precipitation in weld heat affected zones), or it can be found as the optimal pathway to the desired properties (e.g. multi-step heat treatments of aluminium alloys). The presented work addresses both on an experimental and on a modelling point of view some of these effects, both in aluminium alloys (the Al-Zn-Mg and Al-Zr-Sc systems) and in a Fe-Cu alloy. [source] Development and Testing of Energetic Materials: The Concept of High Densities Based on the Trinitroethyl FunctionalityADVANCED FUNCTIONAL MATERIALS, Issue 3 2009Michael Göbel Abstract The development of new energetic materials is an emerging area of materials chemistry facilitated by a worldwide need to replace materials used at present, due to environmental considerations and safety requirements, while at the same time securing high performance. The development of such materials is complex, owing to the fact that several different and apparently mutually exclusive material properties have to be met in order for a new material to become widely accepted. In turn, understanding the basic principles of structure property relationships is highly desirable, as such an understanding would allow for a more rational design process to yield the desired properties. This article covers the trinitroethyl functionality and its potential for the design of next generation energetic materials, and describes relevant aspects of energetic materials chemistry including theoretical calculations capable of reliably predicting material properties. The synthesis, characterization, energetic properties, and structure property relationships of several new promising compounds displaying excellent material properties are reported with respect to different kinds of applications and compared to standard explosives currently used. Based on a review of trinitroethyl-containing compounds available in the literature, as well as this new contribution, it is observed that high density can generally be obtained in a more targeted manner in energetic materials taking advantage of noncovalent bonding interactions, a prerequisite for the design of next generation energetic materials. [source] Food process engineering and dairy technology at the Technical University of MunichINTERNATIONAL JOURNAL OF DAIRY TECHNOLOGY, Issue 4 2003Ulrich Kulozik The Chair for Food Process Engineering and Dairy Technology at the Technical University of Munich in Freising-Weihenstephan has been installed since 1992 in a new building hosting modern and well-equipped laboratories and pilot-plant facilities. Its objectives in terms of research are to participate in the development of the scientific understanding of complex food systems and their constitutive components, and the way they interact with the process during manufacturing. The aim is to allow the production of food products with desired properties, improved quality and optimal safety, while ensuring an efficient use of raw materials and of the energy required for industrial production. The methodology used involves the fractionation of complex systems and the systematic study of their constitutive components taken in isolation as well as in various combinations. Milk, as a naturally complex raw material, receives particular attention, but research activities increasingly extend to other functional food substrates such as eggs. The research activities are organized into three working groups that reflect the core competencies developed at the chair throughout the years: Bio-Processes and Aseptic Processing, Formation of Structures in Food Systems, and Protein Technology. Its key position within the ,Centre of Life and Food Science' of the Technical University of Munich fosters interdisciplinary interactions with many specialized scientists, and therefore provides a broad perspective regarding the comprehension of the complex implications of modern food and pharmaceutical product manufacturing. [source] The ordered weighted geometric averaging operatorsINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 7 2002Z. S. Xu The ordered weighted averaging (OWA) operator was introduced by Yager.1 The fundamental aspect of the OWA operator is a reordering step in which the input arguments are rearranged in descending order. In this article, we propose two new classes of aggregation operators called ordered weighted geometric averaging (OWGA) operators and study some desired properties of these operators. Some methods for obtaining the associated weighting parameters are discussed, and the relationship between the OWA and DOWGA operators is also investigated. © 2002 Wiley Periodicals, Inc. [source] Oxycellulose: Significant characteristics in relation to its pharmaceutical and medical applicationsADVANCES IN POLYMER TECHNOLOGY, Issue 3 2009Bajerová Martina Abstract As a biomaterial, cellulose can be converted into a wide range of derivatives with desired properties for a variety of medical, biomedical, and pharmaceutical applications. The oxidation of cellulose yields oxidized cellulose (OC, oxycellulose, 6-carboxycellulose). OC represents an important class of biocompatible and bioresorbable polymers. In vivo bioabsorption of OC occurs via chemical depolymerization and enzymatic hydrolysis. Despite the fact OC is well established as a hemostatic agent and is widely used in a clinical practice, it still attracts a great interest and its new applications, especially pharmaceutical, are investigated. The present review is focused on characterization of OC's physical and chemical properties. Its synthesis and mechanisms involved in its in vivo and in vitro biodegradation are discussed. Medical and biomedical applications of OC are summarized, and especially its hemostatic, enterosorbent, and wound-healing properties are described. In addition to these applications, OC could be used as a pharmaceutical excipient in solid (e.g., tablets, microparticles), semisolid (e.g., gels), as well as liquid (e.g., suspensions) dosage forms. © 2009 Wiley Periodicals, Inc. Adv Polym Techn 28:199,208, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20161 [source] Enhancing molecular discovery using descriptor-free rearrangement clustering techniques for sparse data setsAICHE JOURNAL, Issue 2 2010Peter A. DiMaggio Jr. Abstract This article presents a descriptor-free method for estimating library compounds with desired properties from synthesizing and assaying minimal library space. The method works by identifying the optimal substituent ordering (i.e., the optimal encoding integer assignment to each functional group on every substituent site of molecular scaffold) based on a global pairwise difference metric intended to capture smoothness of the compound library. The reordering can be accomplished via a (i) mixed-integer linear programming (MILP) model, (ii) genetic algorithm based approach, or (iii) heuristic approach. We present performance comparisons between these techniques as well as an independent analysis of characteristics of the MILP model. Two sparsely sampled data matrices provided by Pfizer are analyzed to validate the proposed approach and we show that the rearrangement of these matrices leads to regular property landscapes which enable reliable property estimation/interpolation over the full library space. An iterative strategy for compound synthesis is also introduced that utilizes the results of the reordered data to direct the synthesis toward desirable compounds. We demonstrate in a simulated experiment using held out subsets of the data that the proposed iterative technique is effective in identifying compounds with desired physical properties. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source] Exhaustive Structure Generation for Inverse-QSPR/QSARMOLECULAR INFORMATICS, Issue 1-2 2010Tomoyuki Miyao Abstract Chemical structure generation based on quantitative structure property relationship (QSPR) or quantitative structure activity relationship (QSAR) models is one of the central themes in the field of computer-aided molecular design. The objective of structure generation is to find promising molecules, which according to statistical models, are considered to have desired properties. In this paper, a new method is proposed for the exhaustive generation of chemical structures based on inverse-QSPR/QSAR. In this method, QSPR/QSAR models are constructed by multiple linear regression method, and then the conditional distribution of explanatory variables given the desired properties is estimated by inverse analysis of the models using the framework of a linear Gaussian model. Finally, chemical structures are exhaustively generated by a sophisticated algorithm that is based on a canonical construction path method. The usefulness of the proposed method is demonstrated using a dataset of the boiling points of acyclic hydrocarbons containing up to 12 carbon atoms. The QSPR model was constructed with 600 hydrocarbons and their boiling points. Using the proposed method, chemical structures which had boiling points of 100, 150, or 200,°C were exhaustively generated. [source] Current Status of Virtual Combinatorial Library DesignMOLECULAR INFORMATICS, Issue 7 2005Lutz Weber Abstract Combinatorial compound libraries have become an established research tool for finding molecules with desired properties. This review gives an overview on the current status of methods, techniques and design processes for combinatorial libraries. Recent developments include the sequential and parallel use of multiple sophisticated design criteria to select suitable molecules. Diversity measures, physico-chemical and pharmaco-kinetic properties, together with a variety of target and ligand based design methods are being integrated into a seamless process. The proper choice and the implementation of design and selection tools has become a combinatorial problem by itself. However, the application of virtual library design has already yielded an astonishing increase in research productivity and is expected to become a leading tool especially for the discovery of new small molecule drug candidates in the next years. [source] Some important aspects in designing high molecular weight poly(L -lactic acid),clay nanocomposites with desired propertiesPOLYMER INTERNATIONAL, Issue 12 2008Subhendu Ray Chowdhury Abstract BACKGROUND: The main aim of the work reported here was to investigate the effect of clay aspect ratio and functional edge group on the dispersion, degree of order of clays and interfacial strength of high molecular weight poly(L -lactic acid) (PLLA),clay amorphous nanocomposites and consequently their properties. Three kinds of clays (two montmorillonites (SMMTC18 and NMMTC18) and one fluoro-mica (MC18) with the same surfactant) were used to synthesize three amorphous nanocomposites. Thermomechanical properties, permeability, etc., were compared among composites and with pure PLLA. RESULTS: From X-ray diffraction and transmission electron microscopy, both MMTs with lower aspect ratio showed better dispersion and greater degree of disorder, which led to stronger interfacial strength and consequently higher storage modulus than MC18-based composites. All composites showed better properties than pure PLLA. The oxygen barrier efficiencies of SMMTC18- and NMMTC18-based composites were higher than that of the MC18-based composites. Due to the highest exposed area and probably stronger interactions, SMMTC18 had the highest nucleating efficiency. CONCLUSIONS: Along with aspect ratio, dispersion and degree of intercalation, the interfacial strength of composites and degree of order of clays are also important issues for property development. Compared to reported results in the literature, our amorphous composites showed less of an improvement of thermomechanical properties as real reinforcement was solely from clays. Copyright © 2008 Society of Chemical Industry [source] FT-IR Investigation into the miscible interactions in new materials for optical devicesPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 6 2003Lakshmi Sharma Abstract In this article we determine the miscibility of azobenzene derivative (poly(4-(N-(2-methacryloyloxyethyl)-N-ethylamino)-4,-nitroazobenzene)90 -co-(methyl methacrylate)10)/poly(vinyl acetate) (PVAc) and azobenzene derivative/poly(vinyl chloride) (PVC) blends using Fourier Transform infrared (FT-IR) spectroscopy. With this method we can clearly identify the exact interactions responsible for miscibility. In the azobenzene derivative 50:50PVAc blend new peaks were evident at 2960, 2890, 1237 and 959,cm,1, these peaks depict miscible interactions. These wavenumbers indicate that the miscible interactions occurring are from the CH stretching band, the vinyl acetate CO, conjugated to the ester carbonyl, the cis-transformation NN stretch frequency and the acetate ester weak doublet. The azobenzene derivative 80:20PVC blend display peaks identical in profile to the blend homopolymers, indicating no miscible interactions. However, this could be due to overlapping of peaks within the same wavenumber region, making resolution difficult. This research demonstrates FT-IR can deduce favorable interactions for miscibility and therefore numerous miscible blends can successfully be calculated if possessing the same groups responsible for miscibility. This paves the way for a new generation of designer optical materials with the desired properties. Copyright © 2003 John Wiley & Sons, Ltd. [source] Foldon-guided self-assembly of ultra-stable protein fibersPROTEIN SCIENCE, Issue 9 2008Anshul Bhardwaj Abstract A common objective in protein engineering is the enhancement of the thermodynamic properties of recombinant proteins for possible applications in nanobiotechnology. The performance of proteins can be improved by the rational design of chimeras that contain structural elements with the desired properties, thus resulting in a more effective exploitation of protein folds designed by nature. In this paper, we report the design and characterization of an ultra-stable self-refolding protein fiber, which rapidly reassembles in solution after denaturation induced by harsh chemical treatment or high temperature. This engineered protein fiber was constructed on the molecular framework of bacteriophage P22 tail needle gp26, by fusing its helical core to the foldon domain of phage T4 fibritin. Using protein engineering, we rationally permuted the foldon upstream and downstream from the gp26 helical core and characterized gp26-foldon chimeras by biophysical analysis. Our data demonstrate that one specific protein chimera containing the foldon immediately downstream from the gp26 helical core, gp26(1-140)-F, displays the highest thermodynamic and structural stability and refolds spontaneously in solution following denaturation. The gp26-foldon chimeric fiber remains stable in 6.0 M guanidine hydrochloride, or at 80°C, rapidly refolds after denaturation, and has both N and C termini accessible for chemical/biological modification, thereby representing an ideal platform for the design of self-assembling nanoblocks. [source] Ridge regression in two-parameter solutionAPPLIED STOCHASTIC MODELS IN BUSINESS AND INDUSTRY, Issue 6 2005Stan Lipovetsky Abstract We consider simultaneous minimization of the model errors, deviations from orthogonality between regressors and errors, and deviations from other desired properties of the solution. This approach corresponds to a regularized objective that produces a consistent solution not prone to multicollinearity. We obtain a generalization of the ridge regression to two-parameter model that always outperforms a regular one-parameter ridge by better approximation, and has good properties of orthogonality between residuals and predicted values of the dependent variable. The results are very convenient for the analysis and interpretation of the regression. Numerical runs prove that this technique works very well. The examples are considered for marketing research problems. Copyright © 2005 John Wiley & Sons, Ltd. [source] Highly avid magnetic bead capture: An efficient selection method for de novo protein engineering utilizing yeast surface displayBIOTECHNOLOGY PROGRESS, Issue 3 2009Margaret Ackerman Abstract Protein engineering relies on the selective capture of members of a protein library with desired properties. Yeast surface display technology routinely enables as much as million-fold improvements in binding affinity by alternating rounds of diversification and flow cytometry-based selection. However, flow cytometry is not well suited for isolating de novo binding clones from naïve libraries due to limitations in the size of the population that can be analyzed, the minimum binding affinity of clones that can be reliably captured, the amount of target antigen required, and the likelihood of capturing artifactual binders to the reagents. Here, we demonstrate a method for capturing rare clones that maintains the advantages of yeast as the expression host, while avoiding the disadvantages of FACS in isolating de novo binders from naïve libraries. The multivalency of yeast surface display is intentionally coupled with multivalent target presentation on magnetic beads,allowing isolation of extremely weak binders from billions of non-binding clones, and requiring far less target antigen for each selection, while minimizing the likelihood of isolating undesirable alternative solutions to the selective pressure. Multivalent surface selection allows 30,000-fold enrichment and almost quantitative capture of micromolar binders in a single pass using less than one microgram of target antigen. We further validate the robust nature of this selection method by isolation of de novo binders against lysozyme as well as its utility in negative selections by isolating binders to streptavidin-biotin that do not cross-react to streptavidin alone. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source] Produktdesign , Möglichkeiten der ProduktgestaltungCHEMIE-INGENIEUR-TECHNIK (CIT), Issue 8 2004W. Rähse Dr.-Ing.Article first published online: 29 JUL 200 Abstract Die Entwicklung leistungsstarker, auf den Anwendungsfall zugeschnittener Chemieprodukte erfolgt einerseits über gezielte Veränderungen am Molekül (Product Engineering) und andererseits über zugesetzte Hilfsstoffe, Formulierungen oder Mischungen (Product Design). Das Produktdesign umfasst zusätzlich die optimierte Produkthandhabung und Gestaltung. Es wird für Feststoffe an den Beispielen der Granulierung und des Coatings erläutert sowie konkret für die Qualitätseinstellung in der Papierindustrie und für die Gestaltung von Teigwaren diskutiert. Aus Schmelzen lassen sich über die Extrusionstechnologie beliebige Formen realisieren, z.,B. Folien, Stränge, Fasern, Hohl- bzw. Vollkörper (Flaschen, Rohre, Profile), oder über das Vertropfen/Versprühen entstehen Pulver, Granulate, Schuppen, Kügelchen und Pastillen. Für Flüssigkeiten erfolgt die Beschreibung der Einstellung gewünschter Produktleistungen am Beispiel der Niotenside, das Produktdesign am Beispiel der Milch und eines Öls. Die Kombination beider Produktdimensionen ist für die Lackindustrie dargestellt. Einige Gestaltungsmöglichkeiten von Suspensionen, Pasten und Lösungen werden an der Trocknung matrixverkapselter Enzyme, an der Zeolithherstellung sowie an der Verarbeitung keramischer Massen aufgezeigt. Product Design , Possibilities of Product Design The development of high-performance chemical products tailored to a concrete application is done either by making deliberate changes to a particular molecular structure (product engineering) or by adding auxiliary agents, formulations or mixtures (product design). Product design, besides the design proper, also includes the optimized application of the product. For solids it is exemplified by granulation and coating and discussed in concrete terms for the quality adjustment in the paper industry, and for the design of pasta products. Melts can take any desired shape when extruded, such as films, strands, fibers, hollow or solid bodies (bottles, tubes, sections) or they can be processed by dropping/spraying to produce powders, granulates, flakes, pearls or lozenges. The adjustment the desired properties for liquid products is described for the example of non-ionic surfactants and product design is shown for milk and for an oil. The combination of the two product dimensions is presented for the paint industry. Some design possibilities for suspensions, pastes and solutions are demonstrated by the drying of matrix-encapsulated enzymes, the production of zeolite and the processing of ceramic compounds. [source] Synthesis and Properties of (Triptycenedicarboxylatio)zinc Coordination NetworksCHEMISTRY - A EUROPEAN JOURNAL, Issue 23 2009Sergei Abstract Paddle wheels and pillars: Layered 3D metal,organic frameworks comprised of paddle-wheel coordination units are constructed under a variety of conditions to incorporate bridging ligands (as illustrated) that impart desired properties, such as guest-exchange behavior, luminescence, microporosity, and stability, to the material. (Triptycenedicarboxylato)zinc metal,organic frameworks (MOFs) based on paddle wheel secondary building units (SBUs) with different axial ligands have been prepared. The reproducible formation of the layered paddle-wheel structures from triptycenedicarboxylic acid (H2TDC) and zinc nitrate under various conditions seems to be characteristic of this acid and is utilized for the construction of 3D frameworks by a pillaring approach. We attempted to bring additional functionalities into MOFs by employing the appropriate pillaring ligands, for example, bis(4-pyridyl)- s -tetrazine and bis(4-pyridyl)-dimethoxy- p -phenylenedivinylene, and investigated certain properties of some MOF materials, such as guest-exchange behavior, luminescence, microporosity, and stability. [source] Acoustical Properties of Binary Mixtures of Heptane with Ethyl Acetate or Butyl AcetateCHINESE JOURNAL OF CHEMISTRY, Issue 3 2010Divya Shukla Abstract Mixed solvents rather than single pure liquids are of utmost practical importance in chemical and industrial processes as they provide an ample opportunity for the continuous adjustment of desired properties of the medium. Therefore, ultrasonic velocity (u) and density (,) were measured for the binary mixtures formed by heptane with ethyl acetate or butyl acetate at temperatures 293, 298 and 303 K over the entire composition range. Deviation in ultrasonic velocity (,u), deviation in isentropic compressibility (,,s), and excess intermolecular free length (LEf) have been evaluated using the ultrasonic velocity data and the computed results were fitted to the Redlich-Kister polynomial equation. The values of ,u, ,,s and LEf were plotted against the molar fraction of heptane. The observed positive and negative values of excess parameters were discussed in terms of molecular interaction between the components of the mixtures. Experimental values of ultrasonic velocity and density were compared with the results obtained by theoretical estimation procedures. The results were discussed in terms of average absolute deviation (AAD). [source] Brouwer's fan theorem and unique existence in constructive analysisMLQ- MATHEMATICAL LOGIC QUARTERLY, Issue 4 2005Josef Berger Abstract Many existence propositions in constructive analysis are implied by the lesser limited principle of omniscience LLPO; sometimes one can even show equivalence. It was discovered recently that some existence propositions are equivalent to Bouwer's fan theorem FAN if one additionally assumes that there exists at most one object with the desired property. We are providing a list of conditions being equivalent to FAN, such as a unique version of weak König's lemma. This illuminates the relation between FAN and LLPO. Furthermore, we give a short and elementary proof of the fact that FAN is equivalent to each positive valued function with compact domain having positive infimum. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Better library design: data-driven protein engineeringBIOTECHNOLOGY JOURNAL, Issue 2 2007Javier F. Chaparro-Riggers Abstract Data-driven protein engineering is increasingly used as an alternative to rational design and combinatorial engineering because it uses available knowledge to limit library size, while still allowing for the identification of unpredictable substitutions that lead to large effects. Recent advances in computational modeling and bioinformatics, as well as an increasing databank of experiments on functional variants, have led to new strategies to choose particular amino acid residues to vary in order to increase the chances of obtaining a variant protein with the desired property. Strategies for limiting diversity at each position, design of small sub-libraries, and the performance of scouting experiments, have also been developed or even automated, further reducing the library size. [source] | ||||||||||||||||||||||||||||