bluuebunny/crossref_metadata_2025_split huggingface dataset:
Composite Materials for Aeronautic Application
Authors: Iannone Michele 
Published: September 2011

Abstract
The most important aspects of composite usage in aircraft structures are discussed.
Different kinds of fiber reinforcement and matrix are compared. A large part of the article is focused on carbon epoxy prepregs, that is, preimpregnated materials having a continuous fiber reinforcement and an epoxy resin matrix.
The major issues of prepreg processing are outlined, with a description of the different phases of the process. Most of the discussion is focused on the lay‐up plus autoclave processing, which is the most frequent processing approach.
A short comparison between laminate and sandwich structures is also reported.
“No prepreg” techniques are also listed, such as resin transfer molding and resin infusion molding.
Elements are reported of composite structural properties, including the effect of temperature, aging, and damage tolerance. Some additional information on aging and accelerated aging techniques is also included. The behavior of composites exposed to fire, as well as functional properties (conductivity, acoustic damping, etc.) are also shortly listed.
The advantages of lighter structures are considered taking in account also the cost issues, and some specific applications of composites in the aircraft structures are described, stressing the very fast increase of these materials in the aeronautic structural applications.
Finally, the future trends in the technological improvement of composite material, processes, and structures for aeronautical application are shortly outlined.
Compression Properties of Fibers and Polymer Composites
Authors: Piggott Michael R. 
Published: September 2011

Abstract
The factors controlling the compressive strength and modulus are reviewed. These are the initial straightness of the fibers in the laminate, the compressive strength of the fibers, and the matrix compression properties (yield strength, modulus, etc.). The most recent and reliable compression testing methods are described and the sources of compressive strength and stiffness are discussed. The compressive strengths and stiffnesses of carbon, glass, and aramid laminates are then summarized.
Furan Composites
Authors: Uygun Gok Aysegul 
Published: September 2011

AbstractThis article outlines the major studies on the polyfuran composites published over the past decade. The properties of the polyfuran composites synthesized chemically were modified in the presence of different materials such as conducting polymers, metal oxide, acetylene black, and zeolites. The results were listed, discussed, and compared. It was hoped that this article including relevant data might enhance knowledge about polyfuran composites and lead to new works.
Graphene Composites
Authors: Young Robert J. , Kinloch Ian A. 
Published: September 2011

AbstractThe preparation and structure of different forms of graphene are first of all reviewed. Methods of preparation of graphene such as by exfoliation and chemical vapor deposition are described, and the material produced is shown to be quite different from the graphene oxide formed during the chemical oxidation of graphite. The basic structure and mechanical properties of both graphene and graphene oxide are described, and it is shown that they can both have high levels of stiffness and strength. It is demonstrated how Raman spectroscopy can be used to characterize the different forms of graphene and also follow the deformation of a graphene monolayer in a model composite. It is shown that continuum mechanics can be employed to follow the stress transfer to the graphene monolayer even though it is only one atom thick. Finally, the preparation of bulk nanocomposites based on graphene and graphene oxide is described and the properties of these materials are discussed. It is shown that good reinforcement is only found at relatively low levels of loading of the reinforcement and that, due probably to difficulties with dispersion, challenges still remain in obtaining good mechanical properties for high volume fractions of reinforcement.
Laminated Glass
Authors: Zang M. Y. , Chen S. H. 
Published: September 2011

AbstractLaminated glass has been developing with a history of over 100 years. Then various kinds of glass such as annealed glass, float glass, tempered glass, absorbing glass and films such as PVB, SGP, EVA are described. With the new trend of environmental protection and energy saving, large amounts of new types of laminated glass are emerging when different kinds of glass and films are put together. There are two main methods of producing laminated glass, namely, the dry method and the wet method. And then, three impact tests and two main simulation analysis of laminated glass are introduced. The three impact tests are the drop weight test, Charpy impact test, and Izod impact test respectively. While the two main simulation analysis are finite element method and discrete element method.
Manufacturing of Thermoplastic Fiber‐Reinforced Polymer Composites
Authors: Mitschang Peter 
Published: September 2011

AbstractThis article presents a comprehensive introductory overview of thermoplastic composites manufacturing. From classical to reactive thermoplastics; fibers and textile structures to semifinished products; modern‐day manufacturing processes and post‐processing techniques to the manufacturing process chain associated with these types of materials. The most important topics in the field of thermoplastic fiber‐reinforced polymer composites manufacturing have been collated and covered in a clear and concise manner providing the most important references to the main authorities in each subtopic giving the reader the most important sources for further information.
Mechanical Properties of Molecular Composites
Authors: Hara Masanori 
Published: September 2011

AbstractVarious methods have been developed to make molecular composites, including coagulation,in situpolymerization of a matrix polymer, and the addition of a rigid chain to a flexible chain in block copolymers. However, many systems eventually phase separate due to inherent immiscibility of component polymers on heating; thus, they are not appropriate for melt processing, usually necessary for large‐scale production. In addition, most of the mechanical properties reported are tensile properties of fiber and film specimens. Bulk sample data are rare. This is again due to a lack of thermal consolidation without causing phase separation in many molecular composites. One promising approach to circumventing this problem is introduction of strong intermolecular interactions, such as ion–ion and ion–dipole interactions. In this article, after citing some results on mechanical properties of molecular composites based on nonionic rod‐like molecules, mechanical properties of molecular composites made via ionic interactions (ion–dipole interactions) are described.
Polyurethane Precursors
Authors: Tanzi Maria Cristina 
Published: September 2011

Abstract
This article intends to provide a basic knowledge of polyurethanes (PUs) and their typologies, with particular reference to starting materials, both from a scientific and a commercial point of view. The possible types of PUs are described in short, together with their methods of production. Safety, ecological items, and recycling are considered as well. As a final point, the advantages of the use of PUs in composites production are highlighted, with an indication of the reinforced PU production processes.
Printed Circuit Board Laminates
Authors: Sood Bhanu , Pecht Michael 
Published: September 2011

Abstract
Printed circuit boards (PCBs) are the interconnection medium on which electronic components are assembled to create electronic systems. The primary functions of PCBs are to contain the wiring required to interconnect components electrically, to act as the primary structure to support all components in a circuit, and, in many instances, to conduct away heat generated by the components. With the constant drive for miniaturization, increased functionality, and higher speeds, an increasing number of functions must be accommodated on a PCB within the same size or even in an overall smaller size. The purpose of this article is to describe the typical material makeup, techniques, and manufacturing processes used in PCB fabrication. The article then discusses the common PCB failure modes and associated causes with a focus on process control and inspection techniques that can be used during fabrication. An overview of cost structure and overall impact of introduction of newer processing conditions is also discussed.
Strategien und Taktiken für die metallgesteuerte Synthese von Rotaxanen, Knoten, Catenanen und Verschlingungen höherer Ordnung
Authors: Beves Jonathon E. , Blight Barry A. , Campbell Christopher J. , Leigh David A. , McBurney Roy T. 
Published: September 2011

AbstractMehr als ein Vierteljahrhundert nach der ersten Metalltemplatsynthese eines [2]Catenans in Straßburg existiert nun eine Fülle an Strategien zum Aufbau mechanisch verbundener und verflochtener Strukturen auf molekularer Ebene. Catenane, Rotaxane, Knoten und Borromäische Ringe sind alle erfolgreich über Methoden zugänglich, in denen Metallionen eine Schlüsselrolle spielen. Ursprünglich wurden Metallionen ausschließlich aufgrund ihrer Koordinationschemie verwendet, indem sie entweder die einzelnen Bausteine auf eine Weise anordneten, die durch anschließende Reaktionen die Erzeugung der verschlungenen Produkte ermöglichte, oder indem sie selbst als wesentlicher Bestandteil der Ringe oder als “Stopper” dienten. Vor kurzem wurde die Rolle des Metalls auch auf die Katalyse ausgedehnt: Die Metallionen ordnen die Bausteine nicht nur zu einer verflochtenen oder eingefädelten Struktur an, sondern fördern auch aktiv die Strukturbildung durch kovalenten Einfangen. Dieser Aufsatz fasst die Strategien zur Bildung mechanisch verbundener Molekülstrukturen mit Metallionen zusammen und diskutiert die Taktiken, die zum Aufbau von Überkreuzungen, zur Maximierung der Ausbeuten verschlungener und nichtverschlungener Produkte und zur Bildung eingefädelter oder verflochtener Intermediate durch kovalenten Einfang zur Verfügung stehen.
Funktionelle Gemischtmetall‐organische Gerüste mit Metalloliganden
Authors: Das Madhab C. , Xiang Shengchang , Zhang Zhangjing , Chen Banglin 
Published: September 2011

AbstractDie Immobilisierung funktioneller Zentren innerhalb von Metall‐organischen Gerüsten (MOFs) ist für ihre Fähigkeit zur Erkennung kleiner Moleküle und somit für ihre funktionellen Eigenschaften von großer Bedeutung. Das Metalloligandverfahren ermöglicht es uns, eine Vielzahl unterschiedlicher funktioneller Zentren wie offene, katalytisch aktive und photoaktive Metallzentren, chirale Porenumgebungen und Poren abstimmbarer Größe/Krümmung in Gemischtmetall‐organischen Gerüsten (M′MOFs) zielgerichtet zu immobilisieren. In diesem Kurzaufsatz richten wir die Aufmerksamkeit auf einige wichtige funktionelle M′MOFs mit Metalloliganden für die Gasspeicherung und ‐trennung, die enantioselektive Trennung, die heterogene asymmetrische Katalyse und die Sensorik sowie als photoaktive, nanoskalige Materialien für die Wirkstoff‐Freisetzung und biomedizinische Bildgebung.
Porosity formation by biaxial stretching in polyolefin films filled with calcium carbonate particles
Authors: Qaiss A. , Saidi H. , Fassi‐Fehri O. , Bousmina M. 
Published: September 2011

AbstractPorous polymer films were generated by biaxial stretching of polypropylene (PP) and high‐density polyethylene (HDPE) filled with various amounts of calcium carbonate particles. The porosity of the films was measured by mercury porosimetry, and the obtained results were related to the processing conditions and to the morphology development during the biaxial stretching. The results showed that increasing the calcium carbonate (CaCO3) concentration and the draw ratio resulted in porosity increase for PP‐based composite films and in a decreased porosity in HDPE‐based composite films. Such peculiar behavior was connected to interfacial specific interactions between the matrix and the dispersed particles as well as to the crystallinity of the films. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Characterization of a chelating resin functionalized via azo spacer and its analytical applicability for the determination of trace metal ions in real matrices
Authors: Islam Aminul , Ahmad Akil , Laskar Mohammad Asaduddin 
Published: September 2011

AbstractA selective flame atomic absorption spectrometric method has been developed for the determination of trace amount of metal ions after preconcentration on salicylic acid (SA) loaded Amberlite XAD‐4 resin (AXAD‐4) at suitable pH. The chelating resin AXAD‐4‐SA was characterized based on FTIR, thermal and chemical stability, and hydrogen ion capacity. The sorption capacity was found to be 245.0, 156.2, 155.0, 145.0, 125.0, 122.5, and 70 μmol g−1 for Cu(II), Cr(III), Zn(II), Cd(II), Mn(II), Ni(II), and Co(II), respectively with t1/2 <15 min. All the metals could be eluted by 5 mL of 4 mol L−1 HCl/HNO3 resulting in high preconcentration factor of 200–360 up to a low preconcentration limit of 5.5–10 μg L−1. The accuracy and precision of the developed method was checked by analyzing standard reference materials. The experimental values were not statistically significant from the certified values with <5% RSD. The detection limits were found to be 0.42, 0.57, 0.63, 0.77, 0.94, 0.96, and 1.41 μg L−1, respectively. The analytical utility of the AXAD‐4‐SA for preconcentration and determination of metal ions was explored by analyzing river, canal, sewage, and tap water by direct as well as standard addition method. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Systematic review of exercise training or percutaneous transluminal angioplasty for intermittent claudication
Authors: Frans F A , Bipat S , Reekers J A , Legemate D A , Koelemay M J W 
Published: September 2011

Abstract

Background
The aim was to summarize the results of all randomized clinical trials (RCTs) comparing percutaneous transluminal angioplasty (PTA) with (supervised) exercise therapy ((S)ET) in patients with intermittent claudication (IC) to obtain the best estimates of their relative effectiveness.

Methods
A systematic review was performed of relevant RCTs identified from the MEDLINE, Embase and Cochrane Library databases. Eligible RCTs compared PTA with (S)ET, included patients with IC due to suspected or known aortoiliac and/or femoropopliteal artery disease, and compared their effectiveness in terms of functional outcome and/or quality of life (QoL).

Results
Eleven of 258 articles identified (reporting data on eight randomized clinical trials) met the inclusion criteria. One trial included patients with isolated aortoiliac artery obstruction, three trials studied those with femoropopliteal artery obstruction and five included those with combined lesions. Two trials compared PTA with advice on ET, four PTA with SET, two PTA plus SET with SET and two PTA plus SET with PTA. Although the endpoints in most trials comprised walking distances and QoL, pooling of data was impossible owing to heterogeneity. Generally, the effectiveness of PTA and (S)ET was equivalent, although PTA plus (S)ET improved walking distance and some domains of QoL scales compared with (S)ET or PTA alone.

Conclusion
As IC is a common healthcare problem, defining the optimal treatment strategy is important. A combination of PTA and exercise (SET or ET advice) may be superior to exercise or PTA alone, but this needs to be confirmed. Copyright © 2011 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.
Neuroprotective effects of Tacrolimus (FK‐506) and Cyclosporin (CsA) in oxidative injury
Authors: Yousuf Seema , Atif Fahim , Kesherwani Varun , Agrawal Sandeep Kumar 
Published: September 2011

AbstractThe detrimental effects of hypoxic damage to central nervous system lead to energy depletion, free radical formation, lipid peroxidation (LPO), and increased calcium. We hypothesized that in vitro tacrolimus (FK‐506) and cyclosporine A (CsA) could be protective against hypoxic damage in spinal cord. Dorsal columns were isolated from the spinal cord of adult rats and injured by exposure to hypoxic condition for 1 h, and treated with FK‐506 (0.1 μM) and CsA (0.1 μM). After injury, reperfusion was carried out for 2 h. Tissues were collected, processed for biochemical assays, and 2,3,5‐triphenyltetrazolium chloride (TTC) staining. Spinal cord hypoxia caused a significant decrease (P < 0.001) in mitochondrial ATP (30.64%) and tissue reduced glutathione (GSH) (60.14%) content. Conversely, a significant increase (P < 0.001) in tissue LPO level (57.77%) and myeloperoxidase (MPO) activity (461.24%) was observed in hypoxic group. Mitochondrial swelling was also significantly increased in hypoxic group (90.0%). Treatment with either FK‐506 or CsA showed that significant neuroprotective effects (P < 0.05–0.01) were measured in various parameters in hypoxic groups. FK‐506 and CsA treatment showed increase in ATP by 11.19% and 16.14% while GSH content increased by 66.46% and 77.32%, respectively. Conversely, LPO content decreased by 18.97% and 24.06% and MPO level by 42.86% and 18.66% after FK‐506 and CsA treatment. Calcium uptake was also decreased in mitochondria as exhibited by the increase in absorbance by 11.19% after FK‐506 treatment. TTC staining also showed increased viability after FK‐506 and CsA treatment. In conclusion, present study demonstrates the neuroprotective effect of FK‐506 and CsA treatment against spinal cord hypoxia induced damage is mediated via their antioxidant actions.
Metabolically Stable Cellular Adhesion to Inert Surfaces
Authors: Meldal Morten , Wu Boqian , Diness Frederik , Michael Roice , Hagel Grith 
Published: September 2011

AbstractThe structure of D‐amino acid hexapeptides that promote cellular adhesion was determined by screening D‐amino acid hexapeptide libraries synthesized on otherwise inert beaded PEGA resin. These new adhesion molecules provide a completely stable cellular environment and facilitate the maintenance of a monolayer of cells on beads for extended periods. The presence of the peptides promotes spreading of the cells on the bead surface. Not surprisingly, the molecules contained a significant number of arginines and/or lysines. However, the exact structure of each peptide is quite important for the degree of adhesion observed, and a motif with three or four basic amino acids spaced within amino acids of intermediate polarity clearly prevailed, for example, k‐l/r‐h‐r‐i/v‐r‐a; this maintains a polar/hydrophobic balance.
A Rational Design for the Directed Helicity Change of Polyacetylene Using Dynamic Rotaxane Mobility by Means of Through‐Space Chirality Transfer
Authors: Ishiwari Fumitaka , Fukasawa Kei‐ichiro , Sato Takashi , Nakazono Kazuko , Koyama Yasuhito , Takata Toshikazu 
Published: September 2011

AbstractDirected helicity control of a polyacetylene dynamic helix was achieved by hybridization with a rotaxane skeleton placed on the side chain. Rotaxane‐tethering phenylacetylene monomers were synthesized in good yields by the ester end‐capping of pseudorotaxanes that consisted of optically active crown ethers and sec‐ammonium salts with an ethynyl benzoic acid. The monomers were polymerized with [{RhCl(nbd)}2] (nbd=norbornadiene) to give the corresponding polyacetylenes in high yields. Polymers with optically active wheel components that are far from the main chain show no Cotton effect, thereby indicating the formation of racemic helices. Our proposal that N‐acylative neutralization of the sec‐ammonium moieties of the side‐chain rotaxane moieties enables asymmetric induction of a one‐handed helix as the wheel components approach the main chain is strongly supported by observation of the Cotton effect around the main‐chain absorption region. A polyacetylene with a side‐chain rotaxane that has a shorter axle component shows a Cotton effect despite the ammonium structure of the side‐chain rotaxane moiety, thereby suggesting the importance of proximity between the wheel and the main chain for the formation of a one‐handed helix. Through‐space chirality induction in the present systems proved to be as powerful as through‐bond chirality induction for formation of a one‐handed helix, as demonstrated in an experiment using non‐rotaxane‐based polyacetylene that had an optically active binaphthyl group. The present protocol for controlling the helical structure of polyacetylene therefore provides the basis for the rational design of one‐handed helical polyacetylenes.
4‐Substituted Thioquinolines and Thiazoloquinolines: Potent, Selective, and Tween‐80 in vitro Dependent Families of Antitubercular Agents with Moderate in vivo Activity
Authors: Escribano Jaime , Rivero‐Hernández Cristina , Rivera Hilda , Barros David , Castro‐Pichel Julia , Pérez‐Herrán Esther , Mendoza‐Losana Alfonso , Angulo‐Barturen Íñigo , Ferrer‐Bazaga Santiago , Jiménez‐Navarro Elena , Ballell Lluís 
Published: September 2011

AbstractTwo new families of closely related selective, non‐cytotoxic, and potent antitubercular agents were discovered: thioquinolines and thiazoloquinolines. The compounds were found to possess potent antitubercular properties in vitro, an activity that is dependent on experimental conditions of MIC determination (resazurin test and the presence or absence of Tween‐80). To clarify the therapeutic potential of these compound families, a medicinal chemistry effort was undertaken to generate a lead‐like structure that would enable murine efficacy studies and help elucidate the in vivo implications of the in vitro observations. Although the final compounds showed only limited levels of systemic exposure in mice, modest levels of efficacy in vivo at nontoxic doses were observed.
Tightness of the recentered maximum of the two‐dimensional discrete Gaussian free field
Authors: Bramson Maury , Zeitouni Ofer 
Published: September 2011

AbstractWe consider the maximum of the discrete two‐dimensional Gaussian free field (GFF) in a box and prove that its maximum, centered at its mean, is tight, settling a longstanding conjecture. The proof combines a recent observation by Bolthausen, Deuschel, and Zeitouni with elements from Bramson's results on branching Brownian motion and comparison theorems for Gaussian fields. An essential part of the argument is the precise evaluation, up to an error of order 1, of the expected value of the maximum of the GFF in a box. Related Gaussian fields, such as the GFF on a two‐dimensional torus, are also discussed. © 2011 Wiley Periodicals, Inc.
The Effect of Backbone Constraints: The Case of Water Oxidation by the Oxygen‐Evolving Complex in PSII
Authors: Siegbahn Per E. M. 
Published: September 2011

AbstractThe procedure for fixing atoms of amino acid residues in cluster model calculations on enzymes is reviewed. Examples from recent calculations on photosystem II (PSII) and Mo,Cu‐dependent CO dehydrogenase are given. In this context, the cluster model work on finding a mechanism for OO bond formation and a structure of the oxygen‐evolving complex in PSII is also reviewed. In that work, fixing certain atoms played an important role. The main part of the present study concerns the mechanism in PSII using models based on the new high‐resolution (1.9 Å) X‐ray structure, which is compared to that using the old, theoretically suggested, structure. It is concluded that the mechanism remains the same, with a similar barrier height. Finally, a connection between the OEC structure and Mn,Ca‐containing minerals is also briefly discussed.