bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quality Concepts for the Improved Use of Recycled Polymeric Materials: A Review
Authors: Vilaplana Francisco , Karlsson Sigbritt 
Published: March 2008

AbstractPolymeric waste materials should be considered resources for the manufacture of new products through recycling processes, with a similar status to virgin fossil‐based plastics and biopolymers from renewable resources. Several efforts can be made to achieve this qualitative quantum leap in plastics recycling, and consequently introduce recycled products, with competitive performance, to the market. Scientific knowledge about the degradation processes during the life cycle and the development of fast and reliable analytical methods for the quality assessment of recycled plastics are fundamental to guarantee their performance in new applications. Different strategies—restabilisation, rebuilding, compatibilisation, and addition of elastomers and fillers—can be used to upgrade the structure and properties of polymeric waste streams. This review discusses recent developments in the mechanical recycling of plastics, focusing on how to produce quality materials from waste streams and, thus, contribute to a sustainable management of resources and energy.magnified image
Shaping Polymer Particles by Carbon Nanotubes
Authors: Zhang Shanju , Kumar Satish 
Published: March 2008

AbstractWe report the formation of poly(propylene) spherical and ellipsoidal particles templated by carbon nanotubes via solution crystallization. With an increase in nanotube loading, the particle shape changes from sphere to ellipsoid. In the intermediate concentration range, both spherical and ellipsoidal shapes coexist. The particle size decreases with an increase in nanotube loading.magnified image
Synthesis of Well‐Defined Rod‐Coil Diblock Copolymer of Aromatic Polyether and Polyacrylonitrile by Chain‐Growth Condensation Polymerization and Atom Transfer Radical Polymerization
Authors: Ajioka Naomi , Yokoyama Akihiro , Yokozawa Tsutomu 
Published: March 2008

AbstractThe synthesis of diblock copolymers of aromatic polyether and polyacrylonitrile (PAN) was conducted by chain‐growth condensation polymerization (CGCP) and atom transfer radical polymerization (ATRP) from an orthogonal initiator. When CGCP for aromatic polyether was carried out from a PAN macroinitiator obtained by ATRP with an orthogonal initiator, decomposition of the PAN backbone occurred. However, when ATRP of acrylonitrile was conducted from an aromatic polyether macroinitiator obtained by CGCP followed by introduction of an ATRP initiator unit, the polymerization proceeded in a well‐controlled manner to yield aromatic polyether‐block‐polyacrylonitrile (polyether‐b‐PAN) with low polydispersity. This block copolymer self‐assembled in N,N‐dimethylformamide to form bundle‐like or spherical aggregates, depending on the length of the PAN units in the block copolymer.magnified image
The factorial structure of the Suicide Intent Scale: a comparative study in clinical samples from 11 European regions
Authors: Antretter E. , Dunkel D. , Haring C. , Corcoran P. , De Leo D. , Fekete S. , Hawton K. , Kerkhof A.J.F.M. , Lönnqvist J. , Renberg E. Salander , Schmidtke A. , Van Heeringen K. , Wasserman D. 
Published: March 2008

AbstractAlthough the Suicide Intent Scale (SIS) is a widely used instrument in research on suicidal behavior, comparative research on the latent structure of the SIS has been neglected. To determine whether a general factor model of the SIS is supported, alternative factor models of the SIS were evaluated comparatively in 11 clinical samples. The SIS was applied as part of a structured clinical interview to patients after an episode of non‐fatal suicidal behavior. The samples were drawn from 11 study centers within the frame of the WHO/EURO multicenter study on suicidal behavior. Three different two‐factor and two three‐factor models of the SIS were examined in each sample using principal component analysis with orthogonal Procrustes rotation. The factorial structure of the ‘subjective part’ of the SIS (items 9–14) was strongly supported, whereas an acceptable model fit for the ‘objective part’ was not found. Possible future revisions of ‘objective’ SIS items may be worth consideration. As a limitation, the results of the study might not generalize to other samples that use different definitions of non‐fatal suicidal behavior. Copyright © 2008 John Wiley & Sons, Ltd.
An artificial compressibility algorithm for modelling natural convection in saturated packed pebble beds: A heterogeneous approach
Authors: Visser C. J. , Malan A. G. , Meyer J. P. 
Published: March 2008

AbstractThis work is concerned with the modelling of heat and fluid flow through saturated packed pebble beds. A volume‐averaged set of local thermal disequilibrium governing equations is employed to describe the latter as a heterogeneous porous medium with porosity varying from 0.39 to 0.99. The thermal disequilibrium approach, together with stated porosity upper limit, allows for the modelling of wall effects such as wall channeling and wall–bed radiative heat transfer. The resulting set of coupled non‐linear partial differential equations is solved via a locally preconditioned artificial compressibility method, where spatial discretization is effected with a compact finite volume edge‐based discretization scheme. The latter was done in the interest of accuracy. Stabilization is effected via JST scalar‐valued artificial dissipation. This is the first instance in which an artificial compressibility algorithm is applied to modelling heat and fluid flow through heterogeneous porous materials. For this reason, special attention was given to the calculation of acoustic velocities, stabilization scaling factors, as well as allowable time‐step sizes. The developed technology is validated by application to the modelling of a number of benchmark test cases. Copyright © 2008 John Wiley & Sons, Ltd.
Automatic adaptive FE analysis of thin‐walled structures using 3D solid elements
Authors: Lee C. K. , Xu Q. X. 
Published: March 2008

AbstractIn this study, a new automatic adaptive refinement procedure for thin‐walled structures using 3D solid elements is suggested. This procedure employs a specially designed superconvergent patch recovery (SPR) procedure for stress recovery, the Zienkiewicz and Zhu (Z–Z) error estimator for the a posteriori error estimation, a new refinement strategy for new element size prediction and a special mesh generator for adaptive mesh generation. The proposed procedure is different from other schemes in such a way that the problem domain is separated into two distinct parts: the shell part and the junction part. For stress recovery and error estimation in the shell part, special nodal coordinate systems are used and the stress field is separated into two components. For the refinement strategy, different procedures are employed for the estimation of new element sizes in the shell and the junction parts. Numerical examples are given to validate the effectiveness of the suggested procedure. It is found that by using the suggested refinement procedure, when comparing with uniform refinement, higher convergence rates were achieved and more accurate final solutions were obtained by using fewer degrees of freedoms and less amount of computational time. Copyright © 2008 John Wiley & Sons, Ltd.
Remarkable postbuckling paths analyzed by means of the consistently linearized eigenproblem
Authors: Steinboeck A. , Jia X. , Hoefinger G. , Rubin H. , Mang H. A. 
Published: March 2008

AbstractIn addition to the determination of load levels at critical points of stability problems, frequently the postbuckling behavior is of interest. For non‐linear problems, the so‐called consistently linearized eigenvalue problem is a suitable tangent linearization method, which facilitates determination of stability limits. The solution process of the eigenproblem is significantly simplified by appropriate coordinate transformations. Within this process, characteristic shapes of eigenvalue curves allow identification of bifurcation buckling modes, snap‐through modes, and hilltop buckling modes. Mathematical properties of the eigenvalue curves are addressed and conclusions regarding the shape of postbuckling paths are drawn. Considerations also touch upon the conversion from imperfection sensitivity into insensitivity. The theoretical findings are corroborated by examples dealing with a von Mises truss and a similar discrete system, showing a remarkable postbuckling behavior such as a zero‐stiffness equilibrium path. For both systems, the same approach of stiffness increase allows conversion from imperfection sensitivity into insensitivity. Copyright © 2008 John Wiley & Sons, Ltd.
An efficient discontinuous Galerkin method on triangular meshes for a pedestrian flow model
Authors: Xia Yinhua , Wong S. C. , Zhang Mengping , Shu Chi‐Wang , Lam William H. K. 
Published: March 2008

AbstractIn this paper, we develop a discontinuous Galerkin method on triangular meshes to solve the reactive dynamic user equilibrium model for pedestrian flows. The pedestrian density in this model is governed by the conservation law in which the flow flux is implicitly dependent on the density through the Eikonal equation. To solve the Eikonal equation efficiently at each time level, we use the fast sweeping method. Two numerical examples are then used to demonstrate the effectiveness of the algorithm. Copyright © 2008 John Wiley & Sons, Ltd.
On the long‐time stability of a backward Euler scheme for Burgers' equation with polynomial force
Authors: Djoko J.K. 
Published: March 2008

AbstractIn this work we examine the stability of a finite difference approximation for Burgers' equation. More precisely, we consider a Backward Euler discretization scheme in time and approximated the nonlinear term by a linear expression using techniques from 15. The boundedness of the solution sequence with respect to Δt for t ε [0,∞) is proved with the help of the discrete Gronwall lemmas. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2008
Loss of 9p leads to p16INK4A down‐regulation and enables RB/E2F1‐dependent cell cycle promotion in gastrointestinal stromal tumours (GISTs)
Authors: Haller F , Löbke C , Ruschhaupt M , Cameron S , Schulten H‐J , Schwager S , von Heydebreck A , Gunawan B , Langer C , Ramadori G , Sültmann H , Poustka A , Korf U , Füzesi L 
Published: March 2008

AbstractLoss of chromosome 9p is a reliable predictor of malignant behaviour in gastrointestinal stromal tumours (GISTs). p16INK4A located at 9p21 inhibits the CDK4/6/cyclin D complex from phosphorylating RB. Phosphorylation of RB through CDK4/6/cyclin D in early G1 phase frees the transcription factor E2F1 from RB and enables mRNA transcription of genes essential for G1/S phase transition. This study aims to determine the impact of 9p loss on mRNA and protein expression of p16INK4A and further key cell cycle regulators in the different phases of the cell cycle. Sixty primary GISTs previously characterized for 9p loss by comparative genomic hybridization were analysed for mRNA expression of p16INK4A, p15INK4B, CDK4, CDK6, cyclin D, p21CIP1p27KIP1, CDK2, cyclin E, cyclin B, RB and E2F1, using quantitative RT–PCR. The protein expression of CDK6, CDK2, p21CIP1, p27KIP1 and phosphorylated RB (S807/S811) was evaluated using protein arrays as a novel and highly sensitive platform for profiling of protein abundance and protein phosphorylation. In parallel, the nuclear percentages of immunohistochemical staining for p16INK4A, cyclin D, E2F1 and RB were quantified on a tissue microarray. GISTs with 9p loss had significantly higher proliferation rates, higher metastatic behaviour and shorter disease‐free survival. On the molecular level, GISTs with 9p loss had a significantly reduced mRNA as well as nuclear protein expression of p16INK4A. RB was significantly more phosphorylated in these tumours, together with increased mRNA expression and nuclear staining for E2F1. Furthermore, GISTs with 9p loss had up‐regulation of the late G1/S phase promoters CDK2 and cyclin E. We conclude that loss of 9p accompanied by early G1 phase inhibitor p16INK4A down‐regulation in GISTs facilitates phosphorylation of RB, enabling E2F1‐dependent transcription of genes essential for late G1/S phase transition. This study provides a possible basis for the accelerated proliferation and particularly malignant behaviour in GISTs with 9p loss. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Loss of heterozygosity at 9q32–33 (DBC1 locus) in primary non‐invasive papillary urothelial neoplasm of low malignant potential and low‐grade urothelial carcinoma of the bladder and their associated normal urothelium
Authors: Lopez‐Beltran A , Alvarez‐Kindelan J , Luque RJ , Blanca A , Quintero A , Montironi R , Cheng L , Gonzalez‐Campora R , Requena MJ 
Published: March 2008

AbstractTumour recurrence has a major impact on patients with non‐invasive papillary urothelial tumours of the bladder. To explore the role of DBC1 (deleted in bladder cancer 1 locus), a candidate tumour suppressor gene located at 9q32–33, as prognostic marker we have performed loss of heterozygosity (LOH) testing in 49 patients with primary papillary urothelial tumours and associated normal urothelium. Data from the 38 tumours and 11 specimens of normal urothelium that were informative in the LOH study (D9S195 marker) showed that LOH in urothelium (45.4%) but not in non‐invasive tumours (60.5%) was associated with tumour recurrence (p = 0.026) but not to grade or progression. Also, tumours whose normal urothelium had LOH were larger (p = 0.020) and showed cyclin D1 over‐expression (p = 0.032). Non‐significant increased expression of p53, p21Waf1, apoptotic index and tumour proliferation, and decreased expression of p27Kip1 or cyclin D3 also characterized tumours whose normal urothelium had LOH. The expression of these G1–S modulators, apoptotic index and tumour proliferation was more heterogeneous in papillary urothelial tumours, irrespective of having retained heterozygosity or LOH. Also, Bax expression decreased in papillary urothelial tumours having LOH (p = 0.0473), but Bcl‐2 was unrelated to LOH status. In addition, FGFR3 protein expression decreased in LOH tumours (p = 0.036) and in those having LOH in their normal urothelium (p = 0.022). FGFR3 immunohistochemical expression was validated by western blot in selected cases. The survival analysis selected LOH in normal urothelium as a marker of disease‐free survival (log‐rank 5.32, p = 0.021), progression‐free survival (log‐rank 3.97, p = 0.046) and overall survival (log‐rank 4.26, p = 0.038); LOH in tumours was significant in progression‐free survival (log‐rank 3.83, p = 0.042). It is concluded that LOH at the DBC1 locus in normal urothelium seems to be relevant in the prognosis of non‐invasive papillary tumours of the bladder via selecting cases with increased proliferation, frequent alterations of the G1–S phase modulators, and decreased FGFR3 protein expression. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Effect of glass fibers on rheology, thermal and mechanical properties of recycled PET
Authors: Kráčalík Milan , Pospíšil Ladislav , Šlouf Miroslav , Mikešová Jana , Sikora Antonín , Šimoník Josef , Fortelný Ivan 
Published: March 2008

AbstractPET‐glass fiber composites were prepared by melt mixing of recycled PET with chopped glass fibers (15, 20, and 30 wt%) and their degree of dispersion was assessed by scanning electron microscopy. Rotational rheometry was employed to analyze the interfacial shear strength between the fibers and polymer matrix in the molten state. The composite containing 30 wt% of glass fibers revealed a moderate G′ secondary plateau; hence strong fiber‐matrix interactions were confirmed. Results of mechanical testing were in a good accordance with structural and rheological measurements. The higher rate of mixing under production‐scale conditions resulted in lower fiber‐matrix adhesion and in a similar level of fiber dispersion as compared to the same mixture compounded on pilot‐plant scale. Thermal characterization of the composites was performed by differential scanning calorimetry and total crystalline fraction was analyzed. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
Polymerization of 2‐pentene with Ni(II) α‐diimine complex/M‐MAO catalyst and structure of the polymer
Authors: Endo Kiyoshi , Kondo Yosiyuki 
Published: March 2008

AbstractPolymerization of 2‐pentene with [ArNC(An)C(An)·NAr)NiBr2 (Ar2,6‐iPr2C6H3)] (1‐Ni)/M‐MAO catalyst was investigated. A reactivity between trans‐2‐pentene and cis‐2‐pentene on the polymerization was quite different, and trans‐2‐pentene polymerized with 1‐Ni/M‐MAO catalyst to give a high molecular weight polymer. On the other hand, the polymerization of cis‐2‐butene with 1‐Ni/M‐MAO catalyst did not give any polymeric products. In the polymerization of mixture of trans‐ and cis‐2‐pentene with 1‐Ni/M‐MAO catalyst, the Mn of the polymer increased with an increase of the polymer yields. However, the relationship between polymer yield and the Mn of the polymer did not give a strict straight line, and the Mw/Mn also increased with increasing polymer yield. This suggests that side reactions were induced during the polymerization. The structures of the polymer obtained from the polymerization of 2‐ pentene with 1‐Ni/M‐MAO catalyst consists of CH2CH2CH(CH2CH3), CH2 CH2CH2CH(CH3), CH2CH(CH2CH2CH3), and methylene sequence (CH2)n (n ≥ 5) units, which is related to the chain walking mechanism. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2858–2863, 2008
Global Rainbow Refractometry with a Selective Imaging Method
Authors: Wilms Jochen , Gréhan Gérard , Lavergne Gérard 
Published: March 2008

AbstractOriginally developed to measure the refractive index, global rainbow refractometry also permits the extraction of a size distribution. When this technique is applied to a spray with a large number of non‐spherical particles, the number of small particles tends to be overestimated. A new approach in data acquisition is presented to solve this problem at least partially, resulting in a global rainbow of mainly spherical particles. Thus, measurement errors due to non‐sphericity can be minimized. The global rainbow is constructed from an image series of rainbows of individual droplets, where images of the most spherical droplets are selected by use of certain criteria derived from computations of rainbows of single spheres using the Lorenz‐Mie theory.The method is tested with measurements in a spray. The mean droplet temperature and the size distribution, obtained from the inversion of the global rainbow, are compared to results obtained without using the selective imaging method and to results from other measurement techniques. The comparison of the results shows a better agreement when the selective imaging method is applied, especially for size distribution measurements close to the atomizer where a high amount of non‐spherical droplets can be expected.
Dark proteins: Effect of inclusion body formation on quantification of protein expression
Authors: Iafolla Marco A. J. , Mazumder Mostafizur , Sardana Vandit , Velauthapillai Tharsan , Pannu Karanbir , McMillen David R. 
Published: March 2008

AbstractPlasmid‐borne gene expression systems have found wide application in the emerging fields of systems biology and synthetic biology, where plasmids are used to implement simple network architectures, either to test systems biology hypotheses about issues such as gene expression noise or as a means of exerting artificial control over a cell's dynamics. In both these cases, fluorescent proteins are commonly applied as a means of monitoring the expression of genes in the living cell, and efforts have been made to quantify protein expression levels through fluorescence intensity calibration and by monitoring the partitioning of proteins among the two daughter cells after division; such quantification is important in formulating the predictive models desired in systems and synthetic biology research. A potential pitfall of using plasmid‐based gene expression systems is that the high protein levels associated with expression from plasmids can lead to the formation of inclusion bodies, insoluble aggregates of misfolded, nonfunctional proteins that will not generate fluorescence output; proteins caught in these inclusion bodies are thus “dark” to fluorescence‐based detection methods. If significant numbers of proteins are incorporated into inclusion bodies rather than becoming biologically active, quantitative results obtained by fluorescent measurements will be skewed; we investigate this phenomenon here. We have created two plasmid constructs with differing average copy numbers, both incorporating an unregulated promoter (PLtetO‐1in the absence of TetR) expressing the GFP derivative enhanced green fluorescent protein (EGFP), and inserted them intoEscherichia colibacterial cells (a common model organism for work on the dynamics of prokaryotic gene expression). We extracted the inclusion bodies, denatured them, and refolded them to render them active, obtaining a measurement of the average number of EGFP per cell locked into these aggregates; at the same time, we used calibrated fluorescent intensity measurements to determine the average number of active EGFP present per cell. Both measurements were carried out as a function of cellular doubling time, over a range of 45–75 min. We found that the ratio of inclusion body EGFP to active EGFP varied strongly as a function of the cellular growth rate, and that the number of “dark” proteins in the aggregates could in fact be substantial, reaching ratios as high as approximately five proteins locked into inclusion bodies for every active protein (at the fastest growth rate), and dropping to ratios well below 1 (for the slowest growth rate). Our results suggest that efforts to compare computational models to protein numbers derived from fluorescence measurements should take inclusion body loss into account, especially when working with rapidly growing cells. Proteins 2008. © 2008 Wiley‐Liss, Inc.
Humidity‐sensitive characteristic of Ba0.99La0.01SnO3
Authors: Upadhyay Shail 
Published: March 2008

AbstractSamples of Ba0.99La0.01SnO3 (abbreviated name BSL01) have been synthesized by a solid‐state ceramic route at 1200 °C for 4 h. Synthesized powders have been characterized using techniques such as X‐ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X‐ray analysis (EDXA). From XRD data, single‐phase solid‐solution formation has been confirmed. SEM of the sample exhibited a porous nature with small grain size in the range 0.2–0.4 μm. EDXA showed that the surface of the sample is barium deficient and oxygen rich. The distribution in pore size, average pore diameter and% porosity were obtained from the mercury‐intrusion method. The average pore diameter and% porosity are 0.34 μm and 26, respectively. At room temperature the effect of humidity on conductance and capacitance in the frequency range 20 Hz – 1 MHz and relative humidity (RH) range 10–95% have been measured. It is observed that frequency has more influence on capacitance as compared to resistance. The variation of conductivity with RH is linear whereas of the capacitance is nonlinear. The response and recovery times are 44 s and 56 s, respectively. The hygroscopic nature of the sample has been supported by Fourier transforms infrared (FTIR) and thermogravimetric analysis (TGA) data. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)