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Reddy's layerwise laminate plate theory is employed for the closed-form analysis of free-edge effects in layered plates of arbitrary non-orthotropic layups. The approach consists of the subdivision of the physical laminate layers ...
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Reddy's layerwise laminate plate theory is employed for the closed-form analysis of free-edge effects in layered plates of arbitrary non-orthotropic layups. The approach consists of the subdivision of the physical laminate layers into an arbitrary number of mathematical layers through the plate thickness. In each interface, a set of unknown displacement functions with respect to the inplane width coordinate is introduced while in the thickness direction layerwise linear Lagrangian interpolation polynomials are employed. The unknown inplane functions are determined from the governing Euler-Lagrange differential equations, derived from the principle of minimum potential energy. A solution approach in the form of decaying exponential functions leads to closed-form analytical representations for all free-edge state variables in a straightforward manner while in the inner laminate regions, the stress state corresponding to Classical Laminate Plate Theory is recovered exactly. The present approach is applicable on a standard personal computer, needs insignificant computational effort even in cases of thick laminates consisting of a high number of layers and is in excellent agreement with reference results from the literature.
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The magnetoelectric composites xNi_(0.4)Zn_(0.6)Fe_20_4—(1 — x)Pb_(0.95)Sr_(0.05)Zr_(0.53)Ti_(0.47)O_3(x = 0, 0.2, 0.4, 0.6, 0.8, 1.0) were prepared by ceramic technology. It is established that these composites have a two-phase...
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The magnetoelectric composites xNi_(0.4)Zn_(0.6)Fe_20_4—(1 — x)Pb_(0.95)Sr_(0.05)Zr_(0.53)Ti_(0.47)O_3(x = 0, 0.2, 0.4, 0.6, 0.8, 1.0) were prepared by ceramic technology. It is established that these composites have a two-phase structure. The magnetic and ferroelectric properties of the composites were studied by measuring the hysteresis loops and the temperature dependences of corresponding quantities on the composite composition. It is revealed that the phase content in the composite strongly affects the properties studied.
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Some trigonometric functions can be expressed by the infinite composition of polynomials. First we need to consider the convergence problem to study infinite compositions of functions. This article discusses the convergence of inf...
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Some trigonometric functions can be expressed by the infinite composition of polynomials. First we need to consider the convergence problem to study infinite compositions of functions. This article discusses the convergence of infinite compositions of entire functions whose constant terms are not necessarily zero.
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A friction and wear model of fiber composite material with abrasive particles on a contact surface has been proposed. The problem of a composite material friction in which fibers are perpendicular to a friction surface and a rigid...
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A friction and wear model of fiber composite material with abrasive particles on a contact surface has been proposed. The problem of a composite material friction in which fibers are perpendicular to a friction surface and a rigid counterbody separated by a layer of spherical rigid particles has been considered. The effect of the material and abrasive particles’ properties on the wear rate and surface degradation has been determined. A comparison of the obtained results with the experimental data has been performed.
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A two-phase laminated composite was prepared by stacking one layer of thickness-polarized 1-3 piezoelectric composite (PECP) plate between two layers of length-magnetized 1-3 magnetostrictive composite (MSCP) plates in the thickne...
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A two-phase laminated composite was prepared by stacking one layer of thickness-polarized 1-3 piezoelectric composite (PECP) plate between two layers of length-magnetized 1-3 magnetostrictive composite (MSCP) plates in the thickness direction. The PECP plate consisted of 0.68 volume-fraction PZT bars embedded in Spurr epoxy matrix, while the MSCP plates comprised 0.51 volume-fraction Terfenol-D particles embedded and magnetically aligned in Spurr epoxy matrix. The dielectric, magnetic and magnetoelectric properties of the laminate were measured as a function of both frequency and magnetic bias field. A giant magnetoelectric voltage coefficient (OCE) of 15.4 V/cm-Oe was observed at the resonance frequency of-59 kHz under a relatively low bias field of 0.75 kOe. This resonance as was -30 times larger than its non-resonance values, showing promising application of the proposed laminate in magnetoelectric conversion devices.
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In the Affordable Composites from Renewable Resources (ACRES) program at the University of Delaware, soybean oil and other plant triglycerides have been made amenable to polymerization using a broad range of chemical routes. The r...
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In the Affordable Composites from Renewable Resources (ACRES) program at the University of Delaware, soybean oil and other plant triglycerides have been made amenable to polymerization using a broad range of chemical routes. The resultant polymers range in properties from soft rubbers to hard thermosets for composite applications. In this paper we present an investigation of the mechanical properties of glass/flax hybrid composites based on these thermoset matrix materials. Composites with different glass/flax ratios and different fiber arrangements were made using a modified soybean oil matrix material. The fiber arrangement was varied to make symmetric and unsymmetric composites. The latter were tested in different modes in flexural tests and drop weight impact tests. The mechanical properties of the composites were found to depend upon the glass/flax ratio and the arrangement of fibers in the composite. On proper selection of the arrangement of fibers in the composite, the glass fibers and flax fibers were found to act synergistically resulting in an improved flexural and impact performance.
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Service-oriented computing (SOC) represents a paradigm for building distributed computing applications over the Internet. In the past decade, Web services composition has been an active area of research and development endeavors f...
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Service-oriented computing (SOC) represents a paradigm for building distributed computing applications over the Internet. In the past decade, Web services composition has been an active area of research and development endeavors for application integration and interoperation. Although Web services composition has been heavily investigated, several issues related to dependability, ubiquity, personalization, among others, still need to be addressed, especially giving the recent rise of several new computing paradigms such as Cloud computing, social computing, and Web of Things. This article overviews the life cycle of Web services composition and surveys the main standards, research prototypes, and platforms. These standards, research prototypes, and platforms are assessed using a set of assessment criteria identified in the article. The paper also outlines several research opportunities and challenges for Web services composition.
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This study aims at developing the screen-printed sensors as a viable means of depositing sensing tracks on composites for their on-line structural health monitoring. Conventional silk screen was employed in order to deposit a nano...
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This study aims at developing the screen-printed sensors as a viable means of depositing sensing tracks on composites for their on-line structural health monitoring. Conventional silk screen was employed in order to deposit a nano-composite solution comprising of a conductive nano-filler (carbon nano-particles) dispersed in a thermoplastic matrix (high density polystyrene) on laminated composite specimens. The solution was deposited using a squeegee and was allowed to dry. Commercially available metal foil strain gauges were also bonded alongside screen-printed sensor in order to compare the response of the screen-printed sensors with the commercially available strain gauges. The sensing ability of these screen-printed sensors was tested on a universal testing machine (MTS 810) in four-point bending configuration using a load cell of 100 kN. The sensor deposited using screen-printing technique underwent tensile loading at the lower side of the laminate. A data linearization and amplification module comprising of commercially available instrumentation amplifier (INA 118) was used in conjunction with data acquisition module (Keithley KUSB 3100). The results obtained show that the screen-printed sensors have higher gauge factors in tensile loading scenario with reasonably linear response as compared to traditional metal foil strain gauges. The ease of the deposition of a nano-composite solution via screen printing also makes the technique a viable alternative to the traditional resin bonded metal foil strain gauges which have to be bonded on the surface. Moreover, screen printing offers unlimited options for the development of smart composites in various configurations for a multitude of structural applications.
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We report the molecular and stable isotopic (δD and δ~(13)C) compositions of long-chain n-alkanes in common insects including the cabbage butterfly, swallowtail, wasp, hornet, grasshopper, and ladybug. Insect n-alkanes are poten...
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We report the molecular and stable isotopic (δD and δ~(13)C) compositions of long-chain n-alkanes in common insects including the cabbage butterfly, swallowtail, wasp, hornet, grasshopper, and ladybug. Insect n-alkanes are potential candidates of the contamination of soil and sedimentary n-alkanes that are believed to be derived from vascular plant waxes. Long-chain n-alkanes (range C_(21-33); maximum C_(23)-C_(29)) are found to be abundant in the insects (31-781μg/dry g), with a carbon preference index (CPI) of 5.1-31.5 and an average chain length (ACL) of 24.9-29.3. The isotopic compositions (mean±1σ, n=33) of the n-alkanes are -195±16‰ for hydrogen and -30.6±2.4‰ for carbon. The insect n-alkanes are depleted in D by approximately 30-40‰ compared with wax n-alkanes from C3 (-155±25‰) and C4 vascular plants (-167±13‰), whereas their δ~(13)C values fall between those of C3 (-36.2±2.4‰) and C4 plants (-20.3±2.4‰). Thus, the contribution of insect-derived n-alkanes to soil and sediment could potentially shift δD records of n-alkanes toward more negative values and potentially muddle the assumed original C3/C4 balance in the δ~(13)C records of the soil and sedimentary n-alkanes. n-Alkenes are also found in three insects (swallowtail, wasp and hornet). They are more depleted in D relative to the same carbon numbered n-alkanes (δD_(n-alkene)-δD_(n-alkane)=-17±16‰), but the δ~(13)C values are almost identical to those of the n-alkanes (δ~(13)C_(n-alkene)-δ~(13)C_(n-alkane)=0.1±0.2‰). These results suggest that these n-alkenes are desaturated products of the same carbon numbered n-alkanes.
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In this paper,amino acid compositions arecombined with some protein sequence properties(physio-chemical properties)to predict protein structural classes.Weare able to predict protein structural classes using a mathe-matical model ...
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In this paper,amino acid compositions arecombined with some protein sequence properties(physio-chemical properties)to predict protein structural classes.Weare able to predict protein structural classes using a mathe-matical model that combines the nearest neighbor algorithm(NNA),mRMR(minimum redundancy,maximum rele-vance),and feature forward searching strategy.Jackknifecross-validation is used to evaluate the prediction accuracy.As a result,the prediction success rate improves to 68.8%,which is better than the 62.2% obtained when using onlyamino acid compositions. Therefore,we conclude that thephysiochemical properties are factors that contribute to theprotein folding phenomena and the most contributing fea-tures are found to be the amino acid composition. We expectthat prediction accuracy will improve further as moresequence information comes to light.A web server for pre-dicting the protein structural classes is available at http://app3.biosino.org:8080/liwenjin/index.jsp
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