bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polymer/Wood Composites
Authors: Renner Károly , Móczó János , Pukánszky Béla 
Published: July 2012

AbstractThe use of thermoplastic composites reinforced with natural fibers is a mature technology now with a considerable growth rate. The properties of all polymer/wood composites are determined by four factors: component properties, composition, structure, and interfacial interactions. Matrix stiffness determines the extent of reinforcement, while aspect ratio and particle size are the most important characteristics of the wood. Wood content is usually very large in order to achieve maximum effect and lowest possible price. At large fiber content, wood particles can touch each other purely from geometrical reasons resulting in a kind of aggregation which decreases composite strength. Alignment of the fibers, that is, orientation is the other structural factor that influences composite properties considerably. Interfacial interactions are inherently weak in most commodity thermoplastic/wood composites. External load initiates various micromechanical deformation processes in these materials: shear yielding of the matrix, debonding, fiber pullout, or fiber fraction may occur simultaneously or consecutively. Because of easy debonding, interactions must be modified usually by coupling in most composites. In the case of strong interfacial adhesion, the inherent strength of the wood particles may limit the maximum strength of the composites. A brief summary of processing technologies and main application areas are also presented at the end of the article.
Polysulfone Thermoplastic CompositesAdapted fromPolysulfone Thermoplastic Composites, First Edition.
Authors: Michno M. J. , Matzner M. , Kwiatkowski G. T. 
Published: July 2012

AbstractThermoset composite systems, such as those based on epoxy resins, have been known for a long time. These systems suffer from a series of drawbacks, which include a limited number of fabrication processes, the inability to reuse scrap or rework cured parts, and a general lack of toughness. These drawbacks are related to the need to perform chemical reactions on resin intermediates that lead to cross‐linked polymer networks. The continuous development of new thermoplastic resins has provided novel, tough materials that maintain attractive properties over a wide temperature range, and that can be used for prolonged periods at elevated temperatures. Concurrently, novel, rapid fabrication processes are being developed to provide lower cost options for production of composite structures. Examples of engineering high performance polymers useful in composite structures include the amorphous polysulfones and the closely related crystalline poly(aryl ketone)s.Polysulfone thermoplastic composites are presented in this article; in particular, polysulfone polymers and their properties such as mechanical and thermal properties are discussed. Finally, some exemples of polysulfone composites are reported.
Particulate Composites by Powder Injection Molding
Authors: German Randall M. 
Published: July 2012

Abstract
A few unique aspects of composite structures are attained using a powder injection molding (PIM) approach. First, since the materials are not melted, it is possible combine different materials into a single component. Significant flexibility is possible by adjusting the size, size ratio, amount, and particle shape. Thus, insoluble systems such as aluminum–silicon carbide or tungsten–copper are fabricated from mixed powders. An alternative is to injection‐mold the high temperature phase and infiltrate the porous skeleton using liquid metal. But the most important advantage of powder routes is in the ability to fabricate very complicated shapes. This is the key advantage in microelectronics, human implants, and wear applications. It is in this regard that the PIM process excels.
Recycling of Carbon Fiber Composites
Authors: Pisanova Elena 
Published: July 2012

Abstract
The recycling of carbon fiber composites involves significant technical and economic challenges. Current work is focused on the development of efficient and cost‐effective methods to break down the matrix and extract the fibers without damaging the fibers or degrading their mechanical properties. There are several drivers for this effort, including the desire for environmentally friendly waste recycling, governmental regulations, and economic advantages for post consumer applications in automotive and other industries.
Recycling Thermoset Composite Materials
Authors: Pickering Stephen J. 
Published: July 2012

AbstractIn this article, the recycling of thermoset composites is described. Thermosetting polymers, once cured, cannot be remolded by melting and so the methods used for recycling thermoplastics cannot be used. Recycling is therefore carried out by one of two methods. The waste composite materials may be reduced in size to make powdered and fibrous materials that may be used as constituents in new composites. Alternatively, thermal and chemical techniques are used to remove the thermosetting polymer from the fiber reinforcement to produce a fiber recyclate, potentially of high value, that can be used as a reinforcement in new composites. The current state of development of these recycling routes is described and applications for the recycled material considered. Some areas for future research are identified.
Resin Infusion Under Flexible Tooling (RIFT)
Authors: Summerscales John 
Published: July 2012

AbstractThe traditional processes for the manufacture of high performance composite shell structures are (i) vacuum bagging (VB)/VB with autoclave cure VB(A), (ii) resin transfer molding (RTM), and (iii) compression molding. Over recent years, there have been a number of novel “infusion” processes introduced, which span the gap between VB(A) and RTM. The new processes are known by a confusing set of names or acronyms—each company uses a distinct name, yet often the processes are near identical. The infusion processes can be mapped onto four distinct generic processes:Resin infusion in the plane of the fabric (Type I),Resin infusion with a flow medium/transport or distribution mesh (Type II),Resin film infusion (Type III), andSemipreg techniques (Type IV).This article describes the attributes of each of the four variants above and considers their relative advantages and issues.
Space Environment Effects on Polymer Matrix Composites
Authors: Katz Sari , Grossman Eitan 
Published: July 2012

AbstractPolymer matrix composites (PMCs) that exhibit high specific strength, high stiffness, and low coefficient of thermal expansion are widely used in spacecraft as structural materials and other components. The composites are therefore exposed to the harsh space environment which varies with the spacecraft's orbit, the mission duration, and the solar activity. The effects of the space environment components, such as, atomic oxygen, ionizing radiation, thermal cycling, and more, on PMCs are described. These effects are studied via ground simulation andon‐orbitmaterials' exposure. The reaction to the individual and synergistic effects is described. Also included are future expectations for improvement of materials' durability to the space environment mainly by the use of nanotechnology.
Spacecraft Structures: Development
Authors: Marulo Francesco 
Published: July 2012

AbstractCurrent spacecraft designs include materials and structural systems engineered to satisfy a variety of requirements, including structural integrity, damage tolerance, radiation protection, debris/micrometeoroid shielding, and thermal insulation. To comply with these different design requirements, composite materials are tailored and designed for specific application and constraint. A survey of the present status of composite materials technology is made with emphasis on materials and applications useful in spacecraft structures. Information is obtained from the open literature, by attendance at meetings and symposia, and from the World Wide Web.Brief discussions of the theory of composite strengthening and reinforcement mechanics are included. Advantages, disadvantages, problem areas, and actual and potential applications are described. The status of testing, processing, forming, fabrication, and joining are noted, and the opportunities offered by employing composite materials for spacecraft applications are described. The advantages as well as the drawbacks behind the use of composites are also listed with specific reference to the space environment. The most critical aspects, which involve the design and the development of a spacecraft are presented with reference to composite materials specifications and guidelines for selection. Next, the characteristics of fiber‐reinforced composite materials are listed. It is shown that composites possess significant advantages over presently used spacecraft structural materials; these include superior strength‐to‐weight and stiffness‐to‐weight ratios, more design freedom and flexibility, improved resistance to crack propagation, and greater potential for improvement of properties. Major problems include lack of uniform test methods, difficulty of joining, high cost, difficulty of fabrication and processing, and lack of information on reliability and reproducibility, particularly for the more advanced composites.
Stainless Steel Polymer Composites
Authors: Akhtar Farid 
Published: July 2012

Abstract

In electronic, automotive, medical, and aerospace industries, electrostatic discharge (ESD) control and electromagnetic interference (EMI) shielding are important design considerations. Conductive polymer composites are well researched and commercially available materials for ESD control and EMI shielding. Several kinds of conductive fillers are incorporated in the form of particulates and fibers in polymer matrix. A comparison between various conductive fillers in polymer matrix is presented. Stainless steel fibers as conductive filler for polymer matrix offer several advantages. Polymer composites show resistivities in the range of 10
3
−10
6
Ω/sq at a volume fraction as low as 0.75 vol% of stainless steel fibers. The effect of filler size, shape of the filler, critical volume fraction, and effect of polymer matrix on the ESD control/EMI shielding properties of the stainless steel‐reinforced conductive polymer composite is discussed. Important parameters are described to obtain effective ESD control and EMI shielding using stainless fiber polymer matrix composites. Several reported stainless steel‐reinforced polymer composites are summarized and their effectiveness for ESD control and EMI shielding is compared.
Standards for Composite Materials: National, European, and International
Authors: Sims Graham D. 
Published: July 2012

Abstract
The advanced polymer matrix composites (PMCs) industry is an international business, with suppliers, producers, and users all operating globally. Hence, there is a great demand for international standards and specifications to further the use of advanced PMCs and the growth of the industry. In 2010, the many international standards describing test methods for the lower performance PMCs that have discontinuous mat, or fabric reinforcements, have been joined by equivalent methods for the “advanced” continuous fiber‐reinforced systems. This article reviews the development and validation of new standard test methods and documents the current initiatives related to the advanced PMC materials. In particular, the standards and methods being developed by the International Standards Organization (ISO) by the Comitée Européen de Normalisation (CEN) in support of the Single (European) Market and American Society for Testing and Materials (ASTM) are highlighted. These test methods underpin the standards for composite products and intermediate products that are increasingly, being developed, although product standards (e.g., lighting columns, gas cylinders, piping, pultrusions) are not currently covered in this article.
Statistical Fracture Theories
Authors: Zapperi Stefano , Nukala Phani K. V. V. , Alava Mikko J. 
Published: July 2012

AbstractIn this article, we review theories and models used to account for size effects in the fracture of disordered media. We discuss extreme value statistics, fiber bundle models (FBMs), and network models of fracture. We briefly discuss the application of these concepts to the failure of composites.
Structural Composite Design: Concepts and Considerations
Authors: Bruyneel Michael , Diaconu Cezar 
Published: July 2012

AbstractIn this article, the structural composite design process is presented. It is shown that it is an extremely complicated task conducted nowadays with computers and numerical tools. It involves several disciplines, including computer‐aided design (CAD), computer‐aided engineering (CAE), and computer‐aided manufacturing (CAM), in an iterative process where optimization plays a very important role. The CAE of composite structures is described, and several ways to parameterize the laminates are explained. These parameterizations form the basis for the introduction of formulations for the structural composite optimal design, which is the main topic addressed here. Several optimization approaches have been proposed over the past years, but a global solution is not yet available. The ultimate solution procedure should address the problem at the CAD‐CAE‐CAM levels simultaneously, in order to provide light and safe designs that are ready to manufacture. Since the aeronautics industry has driven the innovation in structural composite design, most of the concepts described here are based on the developments carried out for large composite aircrafts.
Structure and Fracture Mechanics of Injection‐Molded Composites
Authors: Karger‐Kocsis József 
Published: July 2012

Abstract
This article gives an overlook on the microstructural development and microstructure‐related fracture and fatigue behaviors of short and long discontinuous fiber‐reinforced injection‐molded composites. The fracture and fatigue crack propagation of the related composites were assessed by fracture mechanical concepts and interpreted as a function of molding‐induced microstructure. The failure caused by different test conditions was analyzed by fractography and discussed. Recommendations were given on how to design injection‐molded thermoplastic matrix composite parts by using the fracture mechanical data.
Superconducting Composites
Authors: Romanovskii Vladimir R. 
Published: July 2012

AbstractThe analysis of the properties and the fields of the applications of multifilamentary superconducting composites is made. Such materials are used to create high field superconducting magnets because they can reach the high value of the critical current density without the loss of the superconductivity. The presented issue contains a review of the important factors governing the choice of superconductors for practical applications. Therefore, the basic theoretical concepts and the formulae required for the laboratory investigation and technical application of these materials are given. The fields of the superconductor's applications are discussed in detail.
Thermal and Mechanical Properties of Copper–Carbon Composites in Electronic Packaging
Authors: Chandra Namas , Silvain Jean‐François , Veillere Amelie , Heintz Jean‐Marc 
Published: July 2012

Abstract
In the field of power electronics, thermal management of silicon chips plays a key role in our ability to increase their performance. It is necessary to dissipate the excess heat in order to prevent heating and consequent deterioration of silicon chips. In this article, we mainly focus on understanding the thermal management requirements of electronic packaging, the key scientific and technological issues, advances in terms of materials, design and processing, and future prospects of the field. In specific, we address how the competing physical, mechanical, and thermal requirements are optimized in heat sinks. Many of the issues addressed can be equally applicable to the design of any component with similar thermal and mechanical requirements including that of heat exchanger tubes. Although, in this article, we focus our attention on copper–carbon system, concepts presented here can be easily extended to other material systems.
3
D
Textile Composites: Mechanical Properties
Authors: Pankow Mark R. , Waas Anthony M. 
Published: July 2012

Abstract
This article discusses many different aspects of 3D woven textile composites. The basics of 3D weaving are introduced along with the fabrication techniques and a discussion of the general types of architectures. Mechanical properties are then examined showing the benefits and drawbacks of the architecture systems. Various different modeling techniques are evaluated including computational techniques that capture architecture‐dependent mechanisms. Finally, the response of 3D woven material is examined under high rates of loading, and its blast and ballistic resistance is discussed.
Temperature and Texture Development during High Speed Friction Stir Processing of Magnesium AZ31
Authors: Hütsch Leon Leander , Hilgert Jakob , Herzberg Klaas , dosSantos Jorge , Huber Norbert 
Published: July 2012

AbstractThe increasing demand for low weight structural materials yields a growing interest in Mg alloys processed at industrially interesting speeds. One aim of this study is to develop defect free welds in the velocity range of 1–10 m · min−1. The resulting welds are subjected to temperature, microstructure and texture investigations. Energy input as well as temperature development under the tool are predicted using numerical models. Image correlation is used to evaluate distortion. The results show that while ensuring constant weld quality, the energy input, sample distortion and grain size can be decreased reaching a threshold at 5 m · min−1. Thermal analysis reveal an asymmetry between AS and RS. The basal planes exhibits a shift from 0 to 45° into processing direction.
A Phosphorescent Nanoparticle‐Based Probe for Sensing and Imaging of (Intra)Cellular Oxygen in Multiple Detection Modalities
Authors: Kondrashina Alina V. , Dmitriev Ruslan I. , Borisov Sergey M. , Klimant Ingo , O'Brien Ian , Nolan Yvonne M. , Zhdanov Alexander V. , Papkovsky Dmitri B. 
Published: July 2012

AbstractMonitoring cell and tissue oxygenation is important for the analysis of cell development and differentiation, mitochondrial function, and common (patho)physiological conditions such as ischemia, cancer, neurodegenerative disorders. A number of materials for sensing cellular oxygen (O2) by optical means have been described in recent years, but the diverse range of biological models and measurement tasks demands more versatile, flexible, and simple O2 sensors. A new cell‐penetrating phosphorescent nanosensor material called MM2 probe is presented. In it, the highly photostable phosphorescent reporter dye Pt(II)‐5,10,15,20‐tetrakis‐(2,3,4,5,6‐pentafluorophenyl)‐porphyrin (PtTFPP; emission at 650 nm) and poly(9,9‐dioctylfluorene) (PFO) fluorophore act as Förster resonance energy transfer (FRET) donor and two‐photon antennae are embedded in cationic hydrogel nanoparticles. Such probe formulation provides efficient delivery into the cell and subsequent sensing and high‐resolution imaging of cellular O2 in different detection modalities, including ratiometric intensity and phosphorescence lifetime‐based sensing under one‐photon and two photon excitation. MM2 probe combines high brightness, photo‐ and chemical stability, low toxicity, and ease of fabrication and use. Its versatility and analytical performance are demonstrated in physiological experiments with adherent cells and neurospheres representing 2D and 3D respiring objects and detection on time‐resolved fluorescent readers, confocal and multiphoton microscopes, and customized microsecond fluorescence/phosphorescence lifetime imaging microscopy (FLIM) systems.
Surface Chemistry Routes to Modulate the Photoluminescence of Graphene Quantum Dots: From Fluorescence Mechanism to Up‐Conversion Bioimaging Applications
Authors: Zhu Shoujun , Zhang Junhu , Tang Shijia , Qiao Chunyan , Wang Lei , Wang Haiyu , Liu Xue , Li Bo , Li Yunfeng , Yu Weili , Wang Xingfeng , Sun Hongchen , Yang Bai 
Published: July 2012

AbstractThe bandgap in graphene‐based materials can be tuned from 0 eV to that of benzene by changing size and/or surface chemistry, making it a rising carbon‐based fluorescent material. Here, the surface chemistry of small size graphene (graphene quantum dots, GQDs) is tuned programmably through modification or reduction and green luminescent GQDs are changed to blue luminescent GQDs. Several tools are employed to characterize the composition and morphology of resultants. More importantly, using this system, the luminescence mechanism (the competition between both the defect state emission and intrinsic state emission) is explored in detail. Experiments demonstrate that the chemical structure changes during modification or reduction suppresses non‐radiative recombination of localized electron‐hole pairs and/or enhances the integrity of surface π electron network. Therefore the intrinsic state emission plays a leading role, as opposed to defect state emission in GQDs. The results of time‐resolved measurements are consistent with the suggested PL mechanism. Up‐conversion PL of GQDs is successfully applied in near‐IR excitation for bioimaging.
A novel HRAS substitution (c.266C>G; p.S89C) resulting in decreased downstream signaling suggests a new dimension of RAS pathway dysregulation in human development
Authors: Gripp Karen W. , Bifeld Eugenia , Stabley Deborah L. , Hopkins Elizabeth , Meien Stefanie , Vinette Kathy , Sol‐Church Katia , Rosenberger Georg 
Published: July 2012

AbstractCostello syndrome is caused by HRAS germline mutations affecting Gly12 or Gly13 in >90% of cases and these are associated with a relatively homogeneous phenotype. Rarer mutations in other HRAS codons were reported in patients with an attenuated or mild phenotype. Disease‐associated HRAS missense mutations result in constitutive HRAS activation and increased RAF‐MEK‐ERK and PI3K‐AKT signal flow. Here we report on a novel heterozygous HRAS germline alteration, c.266C>G (p.S89C), in a girl presenting with severe fetal hydrops and pleural effusion, followed by a more benign postnatal course. A sibling with the same mutation and fetal polyhydramnios showed a Dandy–Walker malformation; his postnatal course was complicated by severe feeding difficulties. Their apparently asymptomatic father is heterozygous for the c.266C>G change. By functional analyses we identified reduced levels of active HRASS89C and diminished MEK, ERK and AKT phosphorylation in cells overexpressing HRASS89C, which represent novel consequences of disease‐associated HRAS mutations. Given our patients' difficult neonatal course and presence of this change in their asymptomatic father, we hypothesize that its harmful consequences may be time limited, with the late fetal stage being most sensitive. Alternatively, the phenotype may develop only in the presence of an additional as‐yet‐unknown genetic modifier. While the pathogenicity of the HRAS c.266C>G change remains unproven, our data may illustrate wide functional and phenotypic variability of germline HRAS mutations. © 2012 Wiley Periodicals, Inc.