bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study on Nanocomposite Thermoplastic Elastomer Gels
Authors: Paglicawan Marissa A. , Balasubramanian Maridass , Kim Jin Kuk 
Published: March 2007

AbstractThe effect of several network‐forming nanoscale materials such as two different types of graphite and multiwalled carbon nanotube on the property development of thermoplastic elastomer (TPE) gels prepared from microphase‐ ordered poly(styrene‐b‐(ethylene‐co‐butylene)‐b‐styrene) (SEBS) triblock copolymer dissolved in paraffin oil was studied. Dynamic rheological measurements of the resultant nanocomposite TPE (NCTPE) gels showed that at temperature between 30 °C to 40 °C below the gel point, the NCTPE gels have dynamic storage modulus greater than loss modulus (G′ and G″), thereby indicating that at ambient temperature a physical network is still present despite the addition of nanoparticles. In general, the nanoparticles lower the gelation temperature. The X‐ray diffraction of NCTPE gels showed that EG2 system exhibited intercalation, those with CNTs exhibited exfoliation and EG1 did not change at all.
Fabrication of Ordered Porous SWNT‐Polymer Nanocomposites by Emulsion Templating
Authors: Lee Sun Hwa , Ham Hyeong Taek , Park Ji Sun , Chung In Jae , Kim Sang Ouk 
Published: March 2007

AbstractPorous polymer films were produced from water‐in‐oil emulsion. Aqueous droplets were dispersed in PMMA/benzene solution without any emulsifier. Simple dip‐coating of the emulsion on a substrate and air‐drying led to hexagonally ordered porous thin films. Porous single walled carbon nanotubes (SWNT)‐polymer composite films were prepared through the similar procedures also. The electrical conductivity of porous SWNT‐polymer composites increased with the content of SWNT.
Miscibility of TPU(PCL diol)/PCL Blend and Its Effect on PCL Crystallinity
Authors: Ajili Shadi Hassan , Ebrahimi Nadereh Golshan 
Published: March 2007

AbstractPoly(ε‐caprolactone) (PCL) was melt blended with thermoplastic polyurethane based on polycaprolactone diol (TPU(PCL diol)). The amount of PCL was varied from 20% to 50% by weight. A single composition dependent glass transition temperature (from DSC) shows the miscibility of system. Also the negative value of polymer‐polymer interaction density, obtained from the analysis of the equilibrium melting point depression, confirms the blends' miscibility. Tc and Tm of the PCL component in the blend decrease significantly with an increase in the TPU content, in comparison with that of pure PCL. The position of the diffraction peak related to (110) planes of PCL in the blends using WAXS has been shifted to lower value. This means the b‐axis of orthorhombic unit cell of PCL is spread out in the blends. On the whole, increase of TPU content in the blend decreases crystallization ability of PCL compared to pure PCL.
Effects of Process Conditions on Surface Replication and Higher‐Order Structure Formation in Micromolding
Authors: Ito Hiroshi , Kazama Kunihiko , Kikutani Takeshi 
Published: March 2007

AbstractInjection molding of thin‐wall parts with microscale surface grooves of polypropylene (PP) and cyclo‐olefin copolymer (COC) were performed for this study. Effects of cavity thickness and process conditions on processability, surface replication, and higher‐order structure of the molded products were evaluated. Surface replication and optical anisotropy of molded products were analyzed using a polariscope, a polarizing optical microscope, SEM, and a confocal laser scanning microscope. Optical anisotropy in the vicinity of the gate was higher than that at any other position; also, optical anisotropy increased with decreased cavity thickness. The replication property at the center area was more pronounced than those of the flow end and the gate vicinity. The distribution of the replication ratio inside the product decreased with increasing mold temperature. Results showed that the replication properties were correlated closely with skin‐shear layer thickness inside the products, and that the replication ratio was lower for greater thickness of the skin‐shear layer.
The Relationship between Rheological Properties and Spraying Behavior of Polymer Dispersions
Authors: Dijkstra Dirk J. , Kiyomoto Yasuhiro , Abe Katsuya , Tani Takaaki , Umemoto Satoshi 
Published: March 2007

AbstractThe influence of the rheological properties on the spraying behavior of an adhesive polyurethane dispersion modified with different thickeners was investigated. The differences in shear rheology for the three different kinds of thickeners were found not to be representative for the spraying behavior. The extended fan sheets and reduced overspray for the water‐soluble thickener correspond to a more pronounced elastic rheological behavior of the dispersion.
Polyurethane Modified Epoxy Adhesives for the Application to FCCL
Authors: Baek Jung‐ok , Park Sun‐joo , Gong Hui‐jin , Kim Wonho 
Published: March 2007

AbstractThe peel strength of blends of epoxy resin/curing agent (diamino diphenyl sulfone, DDS)/ polyurethane was measured using INSTRON 4485 under normal, chemical and thermal treated states. Glass transition temperature was measured by using differential scanning calorimetry (DSC, Pyris1) according to the contents of polyurethane. Adhesive strength was, approximately, 1.3N/mm and there was no significant effect on the peel strength by the chemical and heat cycle treatments. Glass transition temperature of the adhesive increased from 0 °C to 74.76 °C by increasing the contents of polyurethane. The dimensional stability of epoxy adhesives which contain 30wt% of polyurethane was improved about 98% compared to that of neat epoxy adhesives.
Co‐carcinogenic effect of cyclohexanol on the development of preneoplastic lesions in a rat hepatocarcinogenesis model
Authors: Márquez‐Rosado Lucrecia , Trejo‐Solís Cristina , del Pilar Cabrales‐Romero María , Arce‐Popoca Evelia , Sierra‐Santoyo Adolfo , Alemán‐Lazarini Leticia , Fatel‐Fazenda Samia , Carrasco‐Legleu Claudia E. , Villa‐Treviño Saúl 
Published: March 2007

AbstractCyclohexanol is a basic industrial chemical widely used because of its versatility as an industrial solvent. No studies have been conducted to evaluate the carcinogenic/co‐carcinogenic hazards associated with cyclohexanol exposure. In male Fisher 344 rats liver preneoplastic lesions were induced by N‐nitrosodiethylamine (150 mg/Kg) i.p., followed by the tumor promoter 2‐acetylaminofluorene (2‐AAF: 20 mg/kg) orally administered on three consecutive days before partial hepatectomy. The cyclohexanol administration in this hepatocarcinogenesis assay revealed that it has a strong tumor co‐promoter potential. There is clear evidence that oxidative stress and the CYP2E1 are components of carcinogenesis. Although no changes in the lipid peroxidation levels were observed between treated and untreated animals, a significant increase in CYP2E1 expression was observed when cyclohexanol was administered 24 h after the last 2‐AAF dose. On the other hand, levels of the proliferation markers PCNA and Ki‐67 were not increased after treatment with cyclohexanol, but a marked downregulation of the Bax proapoptotic protein was found exclusively in mitochondrial extracts of animals treated with cyclohexanol. This study represents the first report of the ability of cyclohexanol‐induced lesions, when administered simultaneously with 2‐AAF, to potentiate the development of preneoplastic liver. © 2007 Wiley‐Liss, Inc.
Gene transfer therapy for neurodegenerative disorders
Authors: Feigin Andrew , Eidelberg David 
Published: March 2007

AbstractRecent advances in gene transfer technology have led to promising new therapies for neurodegenerative disorders. This article will review methods of gene transfer therapy and applications of these techniques to both genetic and sporadic neurodegenerative illnesses. The article will focus on Parkinson's disease, Huntington's disease, and Alzheimer's disease. Several promising gene therapy approaches to these diseases are being pursued both in animal models and in early human trials. Initial safety–tolerability results from these trials appear promising. It is therefore likely that the number of human trials of gene therapy for neurodegenerative disorders will increase over the coming years. © 2007 Movement Disorder Society
Analysis of Generalised Galerkin methods in the numerical solution of elliptic equations
Authors: Anderssen R. S. , Mitchell A. R. 
Published: March 2007

AbstractThe Petrov‐Galerkin projection method is outlined for the solution of the linear elliptic equation Lu = f with homogeneous boundary conditions. By choosing appropriate finite dimensional trial and test spaces, the methods of weighted residuals, collocation, and H1 Galerkin can be interpreted within the Petrov‐Galerkin projection method framework.The important question of how best to choose the trial and test functions to suit a particular type of problem is then discussed. Objective criteria associated with the matrix which governs the Petrov‐Galerkin numerical process are proposed.
On the treatment of free boundary problems with the heat equation via optimal control
Authors: Baumeister J. 
Published: March 2007

AbstractIn this paper we consider a free boundary problem of general type for the heat equation in one space dimension. We formulate this problem as an optimal control problem and derive necessary conditions for a solution of it. In order to compute a solution of the control problem, we apply the projection‐gradient‐method. Simple numerical examples illustrate the results.
Proteins interacting with the ascidian vitelline‐coat sperm receptor HrVC70 as revealed by yeast two‐hybrid screening
Authors: Harada Yoshito , Sawada Hitoshi 
Published: March 2007

AbstractAscidians are hermaphrodites releasing sperm and eggs nearly simultaneously, but many species are self sterile. We have previously reported that HrVC70 consisting of 12 EGF‐like repeats is a major component of the vitelline coat, functioning as a self/nonself‐recognizable sperm receptor during fertilization of the ascidian Halocynthia roretzi. Here, in order to identify the binding partner of HrVC70, we explored HrVC70‐interacting proteins by yeast two‐hybrid screening. HrVC70 is capable of interacting with HrVC70 precursor HrVC120 itself and also with three additional extracellular and/or transmembrane proteins, HrVLP‐1, ‐2, and HrTTSP‐1. Specific interaction of HrVC120, HrVLP‐1, ‐2, and HrTTSP‐1 with HrVC70 was confirmed by exchanging prey and bait, and also by a pulldown assay using the GST‐fusion proteins. HrVLP‐1 and ‐2 are proteins structurally related to HrVC120; both are expressed in the oocytes and may be novel components of the ascidian vitelline coat. HrTTSP‐1 appears to be a member of the serine protease family with type II transmembrane topology. HrTTSP‐1 is expressed in the testis and its gene product contains multiple conserved motifs known to be involved in protein–protein or protein–carbohydrate interactions. Close inspection revealed that the protease domain of HrTTSP‐1 is considerably divergent, in particular around the region of the catalytic center Ser residue. Possible roles of these proteins in ascidian fertilization are also discussed. Mol. Reprod. Dev. 74: 1178–1187, 2007. © 2007 Wiley‐Liss, Inc.
Active caspase‐3 and ultrastructural evidence of apoptosis in spontaneous and induced cell death in bovine in vitro produced pre‐implantation embryos
Authors: Gjørret Jakob O. , Fabian Dušan , Avery Birthe , Maddox‐Hyttel Poul 
Published: March 2007

AbstractIn this study we investigated chronological onset and involvement of active caspase‐3, apoptotic nuclear morphology, and TUNEL‐labeling, as well as ultrastructural evidence of apoptosis, in both spontaneous and induced cell death during pre‐implantation development of bovine in vitro produced embryos. Pre‐implantation embryos (2‐cell to Day 8 blastocysts) were cultured with either no supplementation (untreated) or with 10 µM staurosporine for 24 hr (treated). Embryos were subjected to immunohistochemical staining of active caspase‐3, TUNEL‐reaction for detection of DNA degradation and DAPI staining for detection of apoptotic nuclear morphology, and subjected to fluorescence microscopy. Additionally, treated and untreated blastocysts were fixed and processed for ultrastructural identification of apoptosis. Untreated embryos revealed no apoptotic features at 2‐ and 4‐cell stages. However, active caspase‐3 and apoptotic nuclear morphology were observed in an untreated 8‐cell stage, and TUNEL‐labeling was observed from the 16‐cell stage. Blastomeres concurrently displaying all apoptotic features were present in a few embryos at 16‐cell and morula stages and in all blastocysts. All three features were observed from the 8‐cell stage in treated embryos, and blastomeres with apoptotic features appeared more numerous in treated than in untreated embryos. Ultrastructural evidence of apoptosis occurred with a comparable distribution pattern as apoptotic features detected by fluorescence microscopy in both treated and untreated blastocysts. Activation of caspase‐3 is likely involved in both spontaneous and induced apoptosis in bovine pre‐implantation embryos, and immunohistochemical staining of active caspase‐3 may be used in combination with other markers to identify apoptosis in pre‐implantation embryos. Mol. Reprod. Dev. 74: 961–971, 2007. © 2007 Wiley‐Liss, Inc.
Mice lacking cyclin‐dependent kinase inhibitor p19Ink4d show strain‐specific effects on male reproduction
Authors: Buchold Gregory M. , Magyar Patricia L. , O'Brien Deborah A. 
Published: March 2007

Abstractp19Ink4d is a member of the INK4 family of cyclin‐dependent kinase inhibitors, which are important negative regulators of the G1‐phase cyclin‐dependent kinases CDK4 and CDK6. On a mixed C57BL/6 × 129P2/OlaHsd background, mice deficient for p19Ink4d exhibited defects in male reproductive function including testicular atrophy, alteration in serum follicle stimulating hormone, qualitative increase in germ cell apoptosis, and delayed kinetics of meiotic prophase markers (Zindy et al., 2001. Mol Cell Biol 21:3244–3255; Zindy et al., 2000. Mol Cell Biol 20:372–378). In this study, a quantitative assessment of these aspects of reproductive capacity demonstrated relatively mild deficits in p19Ink4d−/− males compared to controls. These effects did not dramatically worsen in older males although some seminiferous tubule defects were observed. Following marker‐assisted backcrossing into the C57BL/6 background, p19Ink4d−/− males did not display defects in testis weights, sperm numbers, serum FSH, germ cell apoptosis, or kinetics of selected meiotic prophase markers. These studies indicate that a reduction in Ink4 family function by the loss of p19Ink4d is sufficient to induce mild reproductive defects in male mice with a mixed genetic background, but not in the C57BL/6 genetic background. Mol. Reprod. Dev. 74: 1008–1020, 2007. © 2007 Wiley‐Liss, Inc.
Constrained minimax optimization of continuous search efforts for the detection of a stationary target
Authors: Dambreville Frédéric , Le Cadre Jean‐Pierre 
Published: March 2007

AbstractAnalytical resolution of search theory problems, as formalized by B.O. Koopman, may be applied with some model extension to various resource management issues. However, a fundamental prerequisite is the knowledge of the prior target density. Though this assumption has the definite advantage of simplicity, its drawback is clearly that target reactivity is not taken into account. As a preliminary step towards reactive target study stands the problem of resource planning under a min–max game context. This paper is related to Nakai's work about the game planning of resources for the detection of a stationary target. However, this initial problem is extended by adding new and more general constraints, allowing a more realistic modeling of the target and searcher behaviors. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007
Buckling of simply‐supported skew plates
Authors: Edwardes R. J. , Kabaila A. P. 
Published: March 2007

AbstractThe difficulties associated with the solution of the skew plate buckling problem are described, and the work of other writers is summarized.By solving a numerical example, the relative advantages of two proposed refinements to the finite element displacement method are demonstrated: A technique of boundary condition relaxation appears justified and gives favourable results compared with conventional boundary condition specification. A mesh grading technique, which is simple to apply, results in a marked improvement in convergence to a solution.
On suitable formulations of the method of modal analysis for numerical calculations
Authors: Gobmann E. , Krings W. , Waller H. 
Published: March 2007

AbstractThe method of modal analysis is a method widely used in structural analysis of linear systems. After a short introduction two step by step formulations for modal calculations are discussed. One of them is of more theoretical interest, the other is recommended for practical calculations for multi‐degree‐of‐freedom systems because it is efficient in computing time. The first is formulated for the whole system the latter for each mode. Likewise a combination of the method of modal analysis and the LAPLACE transformation is established. The numerical calculation of the LAPLACE transformation is done by using the algorithm of the Fast FOURIER transformation. The advantages of the different formulations for numerical calculations are discussed.
Solution of fixed cost trans‐shipment problems by a branch and bound method
Authors: Hindi K. S. , Brameller A. , Hamam K. M. 
Published: March 2007

AbstractVaried problems in the fields of operation, scheduling, allocation and design in power systems analysis can be formulated as fixed cost trans‐shipment problems. This paper indicates possible areas of application of such formulations, and by exploiting specific characteristics of certain power systems problems presents an efficient branch and bound method for solving them.
Finite element method for spectral modelling of tides
Authors: le Provost Christian , Poncet Alain 
Published: March 2007

AbstractA spectral method for modelling of tides is proposed and applied to the calculation of the M2 component of the tide in the English Channel. The classical non‐linear hyperbolic problem of long wave propagation in shallow waters is transformed into a sequence of elliptic problems by looking at a multiperiodic solution the frequencies of which are previously known. The method is based upon a perturbation technique, but the principal difficulties arise from the non‐analytical form of the quadratic friction term: the main conclusions of the corresponding study only are given here, because the purpose of this paper is to present a practical application of the method to the calculation of a tidal component by the finite element method. The variational formulation of the problem is presented, and the finite element package used is described. Some results are given for the M2 tide in the English Channel: cotidal maps and current fields.
A displacement scheme with drilling degrees of freedom for plane elements
Authors: Cannarozzi Agostino A. , Cannarozzi Mario 
Published: March 2007

AbstractA scheme of boundary displacements with drilling degrees of freedom for plane elements is presented. The scheme is free from zero displacement modes and allows the development of hybrid finite elements with vertex and mid‐side nodes, each node including a drilling degree of freedom besides the translational ones. Four quadrilateral isoparametric hybrid stress elements are implemented, and numerical results for some current test problems are given.
A pseudo‐fully stressed design approach for optimum design of steel frames
Authors: Al‐Salloum Yousef A. 
Published: March 2007

AbstractAn iterative approach based on the fully‐stressed design concept employing scaling to find an efficient search path to the optimum design is developed for statically indeterminate elastic frames subjected to behavioural constraints on member stresses and nodal displacements, and side constraints on member sizes. In this approach the fully stressed solution, which recognizes only the stress constraints, is scaled to the boundary of the feasible design region by employing the other constraints on the structure. The inactive constraints in an iteration are identified by the Kuhn‐Tucker conditions. The computed stresses of the inactive constraints, for the time being, are considered to be the allowable values in order to develop a pseudo‐fully stressed solution with a new set of allowable stresses. Convergence takes places when the normalized change in the value of the objective function between the scaled and unsealed pseudo‐fully stressed designs is less than a specified tolerance. The method employs the established relationships between sectional area, section modulus and moment of inertia of W‐shapes to express the objective and constraint functions in terms of one design variable for each member. The efficiency and accuracy of the method in optimization of structural steel frames is demonstrated by sample problems designed for stress, displacement and minimum size constraints. The algorithm is verified against published results.
An incremental formulation for the prediction of two‐dimensional fatigue crack growth with curved paths
Authors: Kim Ki‐Seok , Lee Hae Sung 
Published: March 2007

AbstractThis paper presents a new incremental formulation for predicting the curved growth paths of two‐dimensional fatigue cracks. The displacement and traction boundary integral equations (BIEs) are employed to calculate responses of a linear elastic cracked body. The Paris law and the principle of local symmetry are adopted for defining the growth rate and direction of a fatigue crack, respectively. The three governing equations, i.e. the BIEs, the Paris law and the local symmetry condition, are non‐linear with respect to the crack growth path and unknowns on the boundary. Iterative forms of three governing equations are derived to solve problems of the fatigue crack growth by the Newton–Raphson method. The incremental crack path is modelled as a parabola defined by the crack‐tip position, and the trapezoidal rule is employed to integrate the Paris law. The validity of the proposed method is demonstrated by two numerical examples of plates with an edge crack. Copyright © 2007 John Wiley & Sons, Ltd.
Numerical comparison of some Hessian recovery techniques
Authors: Vallet M.‐G. , Manole C.‐M. , Dompierre J. , Dufour S. , Guibault F. 
Published: March 2007

AbstractDerivative recovery techniques are used in a posteriori error indicators to drive mesh adaptation. Their behaviour in the core of the computational domain and on boundaries constitutes an important efficiency factor for a subsequent mesh adaptation process. A methodology to compare recovery techniques for second‐order derivatives from a piecewise linear approximation is presented in this paper. A systematic approach to measuring the performance of recovery techniques using analytical functions interpolated on a series of meshes is proposed. The asymptotic behaviour of some recently published recovery techniques, as well as new ones, is numerically assessed on various type of meshes. Recommendations are done on the choice of a recovery technique. Copyright © 2007 John Wiley & Sons, Ltd.