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High Flexibility (high + flexibility)
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] 2-Dimensional code design for an optical CDMA system with a parallel interference cancellation receiverEUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 7 2007Mikaël Morelle The objective of this paper is to design a two-Dimensional Optical Code Division Multiple Access system (2D-OCDMA) for application in access networks, with coding and decoding functions performed by electronic devices. We present a new construction method of Multi-Wavelength Optical Orthogonal Codes (MWOOC), which permits a high flexibility in the code parameters choice. This work evaluates in the noiseless case, the MWOOC potentialities for two receiver structures: a Conventional Correlation Receiver (CCR) and a Parallel Interference Cancellation receiver (PIC). We show that with a PIC receiver, it is possible to design two-Dimensional codes that respect the access specifications. Copyright © 2007 John Wiley & Sons, Ltd. [source] Tuning the Refractive Index of Polymers for Polymer Waveguides Using Nanoscaled Ceramics or Organic Dyes,ADVANCED ENGINEERING MATERIALS, Issue 1-2 2004J. Böhm Plastic Optical Fibers (POF) show advantageous properties like high flexibility and their cost advantage in comparison to glass fibers. The refractive indices of core and cladding have to be modified in order to get total reflectance. Thus, there is a strong demand for refractive index adjustable polymers with improved transmission properties in the visible and the NIR range. Inorganic nanosized particles or organic dyes homogeniously dispersed or solved in the polymer matrix allow a tailored increase or decrease of the refractive index of various polymers. [source] The crystal structure of pyruvate decarboxylase from Kluyveromyces lactisFEBS JOURNAL, Issue 18 2006Implications for the substrate activation mechanism of this enzyme The crystal structure of pyruvate decarboxylase from Kluyveromyces lactis has been determined to 2.26 Å resolution. Like other yeast enzymes, Kluyveromyces lactis pyruvate decarboxylase is subject to allosteric substrate activation. Binding of substrate at a regulatory site induces catalytic activity. This process is accompanied by conformational changes and subunit rearrangements. In the nonactivated form of the corresponding enzyme from Saccharomyces cerevisiae, all active sites are solvent accessible due to the high flexibility of loop regions 106,113 and 292,301. The binding of the activator pyruvamide arrests these loops. Consequently, two of four active sites become closed. In Kluyveromyces lactis pyruvate decarboxylase, this half-side closed tetramer is present even without any activator. However, one of the loops (residues 105,113), which are flexible in nonactivated Saccharomyces cerevisiae pyruvate decarboxylase, remains flexible. Even though the tetramer assemblies of both enzyme species are different in the absence of activating agents, their substrate activation kinetics are similar. This implies an equilibrium between the open and the half-side closed state of yeast pyruvate decarboxylase tetramers. The completely open enzyme state is favoured for Saccharomyces cerevisiae pyruvate decarboxylase, whereas the half-side closed form is predominant for Kluyveromyces lactis pyruvate decarboxylase. Consequently, the structuring of the flexible loop region 105,113 seems to be the crucial step during the substrate activation process of Kluyveromyces lactis pyruvate decarboxylase. [source] A Controllable Self-Assembly Method for Large-Scale Synthesis of Graphene Sponges and Free-Standing Graphene FilmsADVANCED FUNCTIONAL MATERIALS, Issue 12 2010Fei Liu Abstract A simple method to prepare large-scale graphene sponges and free-standing graphene films using a speed vacuum concentrator is presented. During the centrifugal evaporation process, the graphene oxide (GO) sheets in the aqueous suspension are assembled to generate network-linked GO sponges or a series of multilayer GO films, depending on the temperature of a centrifugal vacuum chamber. While sponge-like bulk GO materials (GO sponges) are produced at 40,°C, uniform free-standing GO films of size up to 9,cm2 are generated at 80,°C. The thickness of GO films can be controlled from 200,nm to 1,µm based on the concentration of the GO colloidal suspension and evaporation temperature. The synthesized GO films exhibit excellent transparency, typical fluorescent emission signal, and high flexibility with a smooth surface and condensed density. Reduced GO sponges and films with less than 5,wt% oxygen are produced through a thermal annealing process at 800,°C with H2/Ar flow. The structural flexibility of the reduced GO sponges, which have a highly porous, interconnected, 3D network, as well as excellent electrochemical properties of the reduced GO film with respect to electrode kinetics for the [Fe(CN)6]3,/4, redox system, are demonstrated. [source] Adhesive, Flexible, and Robust Polysaccharide Nanosheets Integrated for Tissue-Defect RepairADVANCED FUNCTIONAL MATERIALS, Issue 16 2009Toshinori Fujie Abstract Recent developments in nanotechnology have led to a method for producing free-standing polymer nanosheets as a macromolecular organization. Compared with bulk films, the large aspect ratio of such nanosheets leads to unique physical properties, such as transparency, noncovalent adhesion, and high flexibility. Here, a biomedical application of polymer nanosheets consisting of biocompatible and biodegradable polysaccharides is reported. Micro-scratch and bulge tests indicate that the nanosheets with a thickness of tens of nanometers have sufficient physical adhesiveness and mechanical strength for clinical use. A nanosheet of 75,nm thickness, a critical load of 9.1,×,104,N m,1, and an elastic modulus of 9.6,GPa is used for the minimally invasive repair of a visceral pleural defect in beagle dogs without any pleural adhesion caused by wound repair. For the first time, clinical benefits of sheet-type nano-biomaterials based on molecular organization are demonstrated, suggesting that novel therapeutic tools for overlapping tissue wounds will be possible without the need for conventional surgical interventions. [source] Graduates' career aspirations and individual characteristicsHUMAN RESOURCE MANAGEMENT JOURNAL, Issue 1 2005Wolfgang Mayrhofer Using the basic distinction between organisational and post-organisational career orientation, this article examines preferences of business school graduates for different types of career fields and systematic differences between people with different career orientations in terms of behavioural characteristics as well as personality traits. The results show that business school graduates clearly distinguish between organisational and post-organisational career fields. Graduates with post-organisational career aspirations display attributes of high flexibility, leadership motivation, selfpromotion/self-assertion, self-monitoring, networking and less self-consciousness. For individuals preferring an organisational career pattern, inverse relationships apply. Some implications of the findings for HR practice are discussed. [source] Mechanical properties and microstructure of acrylonitrile,butadiene rubber vulcanizates reinforced by in situ polymerized phenolic resinJOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2007Linzhong Ye Abstract The phenolic resin (PF) was incorporated into acrylonitrile,butadiene rubber (NBR) vulcanizates by in situ polymerization during the vulcanization process. It was found that the tensile strength, tearing strength, and tensile strength (300% elongation) could be considerably enhanced 59.4, 80.2, and 126.4%, respectively, at an optimum PF content of only 15 phr, but the elongation at break and shore A hardness were only slightly affected on the basis of silica-reinforced NBR vulcanizates. A systematic study of the PF structure formed within the NBR matrix using various experimental schemes and procedures has revealed that the PF resin would form the localized discontinuous three-dimensional interconnected network structures in the NBR matrix. The substantial reinforcement of PF on the mechanical properties of vulcanized NBR were attributed to the morphology, high flexibility, and moderate stiffness of the PF phases and their excellent bonding with rubbers through "rubber to rubber" and interface layer. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007 [source] Context-dependent sexual advertisement: plasticity in development of sexual ornamentation throughout the lifetime of a passerine birdJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 6 2003A. V. Badyaev Abstract Male investment into sexual ornamentation is a reproductive decision that depends on the context of breeding and life history state. In turn, selection for state- and context-specific expression of sexual ornamentation should favour the evolution of developmental pathways that enable the flexible allocation of resources into sexual ornamentation. We studied lifelong variation in the expression and condition-dependence of a sexual ornament in relation to age and the context of breeding in male house finches (Carpodacus mexicanus) , a species that develops a new sexual ornament once a year after breeding. Throughout males' lifetime, the elaboration of ornamentation and the allocation of resources to the development of sexual ornamentation depended strongly on pairing status in the preceding breeding season , males that were single invested more resources into sexual ornamentation and changed ornamentation more than males that were paired. During the initial (post-juvenile) moult, the expression of ornamentation was closely dependent on individual condition, however the condition-dependence of ornamentation sharply decreased throughout a male's lifetime and in older males expression of sexual ornamentation was largely independent of condition during moult. Selection for early breeding favoured greater ornamentation in males that were single in the preceding seasons and the strength of this selection increased with age. On the contrary, the strength of selection on sexual ornamentation decreased with age in males that were paired in the preceding breeding season. Our results reveal strong context-dependency in investment into sexual ornamentation as well as a high flexibility in the development of sexual ornamentation throughout a male's life. [source] Molecular dynamic simulations of nanomechanic chaperone peptide and effects of in silico His mutations on nanostructured functionJOURNAL OF PEPTIDE SCIENCE, Issue 11 2008Abolfazl Barzegar Abstract The nanoscale peptide YSGVCHTDLHAWHGDWPLPVK exhibits molecular chaperone activity and prevents protein aggregation under chemical and/or thermal stress. Here, His mutations of this peptide and their impact on chaperone activity were evaluated using theoretical techniques. Molecular dynamic (MD) simulations with simulated annealing (SA) of different mutant nanopeptides were employed to determine the contribution of the scaffolding His residues (H45, H49, H52), when mutated to Pro, on chaperone action in vitro. The in silico mutations of His residues to Pro (H45P, H49P, H52P) revealed loss of secondary ordered strand structure. However, a small part of the strand conformation was formed in the middle region of the native chaperone peptide. The His-to-Pro mutations resulted in decreased gyration radius (Rg) values and surface accessibility of the mutant peptides under the simulation times. The invariant dihedral angle (,) values and the disrupting effects of the Pro residues indicated the coil conformation of mutant peptides. The failure of the chaperone-like action in the Pro mutant peptides was consistent with their decreased effective accessible surfaces. The high variation of , value for His residues in native chaperone peptide leads to high flexibility, such as a minichaperone acting as a nanomachine at the molecular level. Our findings demonstrate that the peptide strand conformation motif with high flexibility at nanoscale is critical for chaperone activity. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd. [source] Solution structure of nociceptin peptidesJOURNAL OF PEPTIDE SCIENCE, Issue 9 2002Pietro Amodeo Abstract Peptides embedded in the sequence of pre-pro-nociceptin, i.e. nociceptin, nocistatin and orphanin FQ2, have shed light on the complexity of the mechanisms involving the peptide hormones related to pain and have opened up new perspectives for the clinical treatment of pain. The design of new ligands with high selectivity and bioavailability, in particular for ORL1, is important both for the elucidation and control of the physiological role of the receptor and for their therapeutic importance. The failure to obtain agonists and antagonists when using, for nociceptin, the same substitutions that are successful for opioids, and the conformational flexibility of them all, justify systematic efforts to study the solution conformation under conditions as close as possible to their natural environment. Structural studies of linear peptides in solution are hampered by their high flexibility. A direct structural study of the complex between a peptide and its receptor would overcome this difficulty, but such a study is not easy since opioid receptors are membrane proteins. Thus, conformational studies of lead peptides in solution are still important for drug design. This review deals with conformational studies of natural pre-nociceptin peptides in several solvents that mimic in part the different environments in which the peptides exert their action. None of the structural investigations yielded a completely reliable bioactive conformation, but the global conformation of the peptides in biomimetic environments can shed light on their interaction with receptors. Copyright © 2002 European Peptide Society and John Wiley & Sons, Ltd. [source] Benzoxazine containing polyester thermosets with improved adhesion and flexibilityJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 19 2010Alev Tuzun Abstract High molecular weight polyesters containing thermally curable benzoxazine units in the main chain have been synthesized. For this purpose, first the diol functional monomer is synthesized through the Mannich and subsequent ring closure reactions of bisphenol-A, paraformaldehyde, and 5-amino-1-pentanol. Polycondensation of the resulting benzoxazine and pyromellitic dianhydride or 4-4,-(hexafluoroisopropylidene) diphatalic anhydride with or without dibutyltin laurate yielded the corresponding polyesters with the molecular weights between 5800 and 7000 Da. The structures of the precursor diol monomer and the resulting polyesters are confirmed by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy analysis. Curing behavior of both the monomer and polymers has also been studied by differential scanning calorimetry. Flexible films of the polyesters were obtained by solvent casting on tin plates and crosslinked by heating in the absence of any catalyst. The cured films exhibited high flexibility and adhesion on the tin plates as determined by ASTM and DIN tests. Thermal properties of the cured polymers were also investigated by thermogravimetric analysis (TGA). © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4279,4284, 2010 [source] Gel-free sample preparation for the nanoscale LC-MS/MS analysis and identification of low-nanogram protein samplesJOURNAL OF SEPARATION SCIENCE, JSS, Issue 14 2007Marco Gaspari Abstract Protein identification at the low nanogram level could in principle be obtained by most nanoscale LC-MS/MS systems. Nevertheless, the complex sample preparation procedures generally required in biological applications, and the consequent high risk of sample losses, very often hamper practical achievement of such low levels. In fact, the minimal amount of protein required for the identification from a gel band or spot, in general, largely exceeds the theoretical limit of identification reachable by nanoscale LC-MS/MS systems. A method for the identification of low levels of purified proteins, allowing limits of identification down to 1 ng when using standard bore, 75 ,m id nanoscale LC-MS/MS systems is here reported. The method comprises an offline two-step sample cleanup, subsequent to protein digestion, which is designed to minimize sample losses, allows high flexibility in the choice of digestion conditions and delivers a highly purified peptide mixture even from "real world" digestion conditions, thus allowing the subsequent nanoscale LC-MS/MS analysis to be performed in automated, unattended operation for long series. The method can be applied to the characterization of low levels of affinity purified proteins. [source] A flexible RF transmitter module based on flexible printed circuit board by using micro-machining fabrication processMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2010Seong-Sik Myoung Abstract This article presents a flexible RF transmitter module based on flexible printed circuit board (FPCB). The polyimide with micro-machining fabrication technique is employed for realization of FPCB to achieve the high flexibility as well as low loss at microwave frequency band. The active devices in the proposed flexible RF transmitter are design with InGaP/GaAs hetero-junction bipolar transistor monolithic microwave integrated circuit process, and the passive devices such as the filter and interconnection lines are fully integrated on the FPCB board to avoid use of external off-chip components for maximized flexibility. The FPCB transmitter module is designed for a short-distance sensor network based on OFDM communication system, and the measured conversion gain and error vector magnitude of the fabricated flexible transmitter are 27 dB and ,32 dB, respectively. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2636,2639, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25572 [source] SMILIB: Rapid Assembly of Combinatorial Libraries in SMILES NotationMOLECULAR INFORMATICS, Issue 7 2003Andreas Schüller Abstract A software tool was developed for fast combinatorial library enumeration (SMILIB). Its particular features are its simplicity to use, high flexibility in constructing combinatorial libraries and high speed of library construction. SMILIB offers the possibility to construct very large combinatorial libraries using the flexible and portable SMILES format. Libraries are generated at rates of approximately 30,000 molecules per minute. Combinatorial building blocks are attached to scaffolds by means of linkers rather than to concatenate them directly. This allows for creation of easily customized libraries using linkers of different size and chemical nature. A web interface for a limited web-based version of the software is available at URL: www.modlab.de. An unlimited binary version of SMILIB for command line execution on Linux systems is available from this URL. [source] Effect of resin compositions on microwave processing and thermophysical properties of benzoxazine-epoxy-phenolic ternary systems filled with silicon carbide (SiC) whiskerPOLYMER ENGINEERING & SCIENCE, Issue 5 2009Chanchira Jubsilp Microwave processing of silicon carbide (SiC) whisker filled ternary systems based on benzoxazine, epoxy, and phenolic resins has been investigated using an industrial microwave apparatus at a fixed frequency of 2.45 GHz. The low viscosity molding compound and void-free cured specimens can easily be obtained from the resin mixtures. Increasing of epoxy mass fraction in the ternary systems provided a better microwave coupling, therefore, a faster curing time and higher conversion under microwave irradiation. However, the greater amount of epoxy resin in the mixture was observed to retard the traditional thermal cure process as seen in the shifting of the exothermic curing peaks to higher temperature. The higher dielectric constant of epoxy resin comparing with the benzoxazine resin can be attributed to the observed phenomenon. Additionally, benzoxazine fraction was found to render a reduction in linear thermal expansion coefficient of the ternary systems. The development of ternary systems yields the polymer systems with high flexibility in resin-curing agent mixing ratios with relatively high Tg in the broader range of mixing ratios i.e., BEP451-BEP811. Synergism in glass transition temperature of the ternary systems is also observed with the maximum Tg up to 160°C in BEP721. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers [source] Galerkin-type space-time finite elements for volumetrically coupled problemsPROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2003Holger Steeb Dipl.-Ing. The study focuses on error estimation techniques for a coupled problem with two constituents based on the Theory of Porous Media. After developing space-time finite elements for this mixed problem, we extend the numerical scheme to a coupled space-time adaptive strategy. Therefore, an adjoint or dual problem is formulated and discussed, which is solved lateron numerically. One advantage of the presented technique is the high flexibility of the error indicator with respect to the error measure. [source] Option pricing under Markov-switching GARCH processesTHE JOURNAL OF FUTURES MARKETS, Issue 5 2010Chao-Chun Chen This study proposes an N -state Markov-switching general autoregressive conditionally heteroskedastic (MS-GARCH) option model and develops a new lattice algorithm to price derivatives under this framework. The MS-GARCH option model allows volatility dynamics switching between different GARCH processes with a hidden Markov chain, thus exhibiting high flexibility in capturing the dynamics of financial variables. To measure the pricing performance of the MS-GARCH lattice algorithm, we investigate the convergence of European option prices produced on the new lattice to their true values as conducted by the simulation. These results are very satisfactory. The empirical evidence also suggests that the MS-GARCH model performs well in fitting the data in-sample and one-week-ahead out-of-sample prediction. © 2009 Wiley Periodicals, Inc. Jrl Fut Mark 30:444,464, 2010 [source] 2,12-Dichloro-10,20-diphenyl-5,7,15,17-tetrahydro-6H,16H -dibenzo[d,l][1,9,2,6,10,14]dioxotetraazacyclohexadecine-6,16-dione dioxane solvate as a potential macrocyclic hexadentate ligandACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2007Victor N. Khrustalev The macrocyclic title compound crystallizes as a dioxane solvate, C30H22Cl2N4O4·C4H8O2, with two independent formula units in the unit cell. The observed syn conformation is controlled by both intramolecular N,H...O hydrogen bonds and intermolecular C,H..., interactions. The relative macrocyclic inner bore is estimated to be 4.19,Å. In the crystal structure, molecules form dimers via intermolecular C,H..., interactions, and these dimers are, in turn, linked to form columns along the a axis by intermolecular C,H...O hydrogen bonds. Both X-ray diffraction analysis and density functional theory (DFT) calculations reveal that the macrocycle possesses very high flexibility. This property, as well as the presence of six donor atoms accessible for coordination, makes the title macrocycle a very promising ligand for complexation with the majority of transition metals. [source] A new crystal form of human tear lipocalin reveals high flexibility in the loop region and induced fit in the ligand cavityACTA CRYSTALLOGRAPHICA SECTION D, Issue 10 2009Daniel A. Breustedt Tear lipocalin (TLC) with the bound artificial ligand 1,4-butanediol has been crystallized in space group P21 with four protein molecules in the asymmetric unit and its X-ray structure has been solved at 2.6,Å resolution. TLC is a member of the lipocalin family that binds ligands with diverse chemical structures, such as fatty acids, phospholipids and cholesterol as well as microbial siderophores and the antibiotic rifampin. Previous X-ray structural analysis of apo TLC crystallized in space group C2 revealed a rather large bifurcated ligand pocket and a partially disordered loop region at the entrace to the cavity. Analysis of the P21 crystal form uncovered major conformational changes (i) in ,-strands B, C and D, (ii) in loops 1, 2 and 4 at the open end of the ,-barrel and (iii) in the extended C-terminal segment, which is attached to the ,-barrel via a disulfide bridge. The structural comparison indicates high conformational plasticity of the loop region as well as of deeper parts of the ligand pocket, thus allowing adaptation to ligands that differ vastly in size and shape. This illustrates a mechanism for promiscuity in ligand recognition which may also be relevant for some other physiologically important members of the lipocalin protein family. [source] Solvent and Protein Effects on the Structure and Dynamics of the Rhodopsin ChromophoreCHEMPHYSCHEM, Issue 9 2005Ute F. Röhrig Dr. Abstract The structure and dynamics of the retinal chromophore of rhodopsin are investigated systematically in different environments (vacuum, methanol solution, and protein binding pocket) and with different computational approaches (classical, quantum, and hybrid quantum mechanics/molecular mechanics (QM/MM) descriptions). Finite temperature effects are taken into account by molecular dynamics simulations. The different components that determine the structure and dynamics of the chromophore in the protein are dissected, both in the dark state and in the early photointermediates. In vacuum and in solution the chromophore displays a very high flexibility, which is significantly reduced by the protein environment. In the 11- cis chromophore, the bond-length alternation, which is correlated with the dipole moment, is found to be similar in solution and in the protein, while it differs greatly with respect to minimum-energy vacuum structures. In the model of the earliest protein photointermediate, the highly twisted chromophore shows a very reduced bond-length alternation. [source] | |||||||||||||||||||