bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design of a new multi‐turn ion optical system ‘IRIS’ for a time‐of‐flight mass spectrometer
Authors: Nishiguchi Masaru , Ueno Yoshihiro , Toyoda Michisato , Setou Mitsutoshi 
Published: November 2008

AbstractA new multi‐turn ion optical system ‘IRIS’ has been designed for use with a high‐performance time‐of‐flight (TOF) mass spectrometer, which satisfies the new design concepts of time focusing and phase space stability. It has an elliptical flight path composed of four toroidal electric sectors, with a flight path length for one lap of 0.974 m. Dimensions and voltages of sector electrodes have been optimized to satisfy theoretical requirements by simulations using surface charge method. Generally, multi‐turn instruments require an injection and ejection system to inject and eject ions. On the basis of this ion optical study, we have designed an injection and ejection ion optical system, which achieves time focusing for the total system. Furthermore, we have designed novel field‐adjusting electrodes (FAEs) for the perforated sectors in the injection and ejection systems, which accurately correct the electric potential around the perforated sector's hole. We have also used simulations to evaluate mass resolving power and ion transmissions for various lap numbers or flight path lengths. Through these we have confirmed that mass resolving powers of over 100 000 can be achieved with reasonable ion transmissions for a given set of initial conditions. Usually a multi‐turn TOF mass spectrometer with a closed optic axis has mass range limitations from overtaking ions. To solve this problem, a TOF segmentation method is proposed that identifies all peaks in a TOF spectrum, including those from overtaking ions. Copyright © 2008 John Wiley & Sons, Ltd.
Synoptically forced hydroclimatology of major Arctic watersheds in general circulation models; Part 2: Eurasian watersheds
Authors: Finnis Joel , Cassano John J. , Holland Marika , Serreze Mark C. , Uotila Petteri 
Published: November 2008

AbstractA synoptic climatology of daily sea level pressure patterns over Eurasia has been created and used to assess simulations of regional circulation and hydroclimatology from fourteen general circulation models (GCMs). The quality of simulated circulation varies considerably among both individual models and seasons, with summer and winter showing the best agreement with reanalysis data. Close examination of five select models reveals a tendency for GCMs to either over‐ or under‐emphasize the strength and persistence of the winter storm track over Eurasia, with an overemphasized track resulting in better agreement with reanalyses on annual time‐scales. Although pronounced, these biases have relatively little impact on the hydroclimatology of the Ob, Yenisey, and Lena watersheds. Instead, large‐scale precipitation biases appear to be primarily the result of systematic errors in simulated precipitation processes, perhaps related to relevant parameterization schemes. Finally, an effort was made to identify and characterize 20th century precipitation trends related to greenhouse gas induced climate change, by decomposing precipitation time series on the basis of variability in circulation and the mean intensity of precipitation events. Results suggest the influence of anthropogenic climate change over the past forty years is masked by natural variability. Copyright © 2008 Royal Meteorological Society
In situ Raman spectroscopic monitoring of hydroxyapatite as human mesenchymal stem cells differentiate into osteoblasts
Authors: Chiang Huihua Kenny , Peng Feng‐Ying , Hung Shih‐Chieh , Feng Ya‐Ching 
Published: November 2008

AbstractThe differentiation of stem cells into specific cell types is playing an essential role in the development of stem cell therapy, tissue engineering, and regenerative medicine. In this research, Raman microspectroscopy was applied to monitor the development of hydroxyapatite [HA, Ca5 (PO4)3 (OH)], which is associated with the differentiation of the human mesenchymal stem cells (hMSCs) into osteoblasts. Raman spectra exhibited dramatic changes in the HA region, 950–970 cm−1, over the period of 7–21 days after the start of differentiation. This work demonstrates the successful application of Raman spectroscopy for monitoring and quantitatively evaluating hMSC differentiation into osteoblasts. Copyright © 2008 John Wiley & Sons, Ltd.
Two‐ and three‐dimensional transition element families for adaptive refinement analysis of elasticity problems
Authors: Wu D. , Sze K. Y. , Lo S. H. 
Published: November 2008

AbstractIn this paper, new enhanced assumed strain (EAS) and hybrid stress transition element families are developed for 2D and 3D adaptive refinement analysis of elasticity problems. The EAS element families are based on some existing incompatible transition element families. By using the EAS method and the previous incompatible modes, the B‐matrix columns associated with the EAS modes can be directly designed such that their domain integrals vanish automatically and they can be computed more efficiently. For 2D hybrid stress transition element families, it is possible to derive different stress fields that lead to rank‐sufficient transition elements. However, the task becomes intractable for 3D hybrid stress transition elements in which many combinations of mid‐side and mid‐face nodes are possible. This paper proposes to use hybrid stress transition element families in which the assumed stress fields are linearly complete. The new 2D element family is more accurate than the 2D rank‐sufficient element family. The new 3D element family is more accurate than the one with additional bilinear stress modes. Numerical examples reveal that the most accurate transition element families are the newly developed hybrid stress families followed by the EAS families, the incompatible families and then the compatible families. Copyright © 2008 John Wiley & Sons, Ltd.
Parallel Galerkin domain decomposition procedures for parabolic equation on general domain
Authors: Ma Keying , Sun Tongjun , Yang Danping 
Published: November 2008

AbstractParallel Galerkin domain decomposition procedures for parabolic equation on general domain are given. These procedures use implicit Galerkin method in the subdomains and simple explicit flux calculation on the interdomain boundaries by integral mean method or extrapolation method to predict the inner‐boundary conditions. Thus, the parallelism can be achieved by these procedures. These procedures are conservative both in the subdomains and across interboundaries. The explicit nature of the flux prediction induces a time‐step limitation that is necessary to preserve stability, but this constraint is less severe than that for a fully explicit method. L2‐norm error estimates are derived for these procedures. Compared with the work of Dawson and Dupont [Math Comp 58 (1992), 21–35], these L2‐norm error estimates avoid the loss of H−1/2 factor. Experimental results are presented to confirm the theoretical results. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2009
Graded Galerkin methods for the high‐order convection‐diffusion problem
Authors: Liu Song‐Tao , Xu Yuesheng 
Published: November 2008

AbstractWe develop a Galerkin method using the Hermite spline on an admissible graded mesh for solving the high‐order singular perturbation problem of the convection‐diffusion type. We identify a special function class to which the solution of the convection‐diffusion problem belongs and characterize the approximation order of the Hermite spline for such a function class. The approximation order is then used to establish the optimal order of uniform convergence for the Galerkin method. Numerical results are presented to confirm the theoretical estimate.© 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2009
Down syndrome serum screening also identifies an increased risk for multicystic dysplastic kidney, two‐vessel cord, and hydrocele
Authors: Hoffman Jodi D. , Bianchi Diana W. , Sullivan Lisa M. , Mackinnon Brenda L. , Collins Jamie , Malone Fergal D. , Porter T. Flint , Nyberg David A. , Comstock Christine H. , Bukowski Radek , Berkowitz Richard L. , Gross Susan J. , Dugoff Lorraine , Craigo Sabrina D. , Timor‐Tritsch Ilan E. , Carr Stephen R. , Wolfe Honor M. , D'Alton Mary E. 
Published: November 2008

AbstractObjectiveThe FASTER trial compared first and second trimester screening methods for aneuploidy. We examined relationships between maternal serum markers and common congenital anomalies in the pediatric outcome data set of 36 837 subjects.MethodsWe used nested case–control studies, with cases defined by the most common anomalies in our follow‐up database, and up to four controls matched by enrollment site, maternal age and race, enrollment gestational age, and infant gender. Serum markers were dichotomized to ≥ 2 or < 0.5 multiples of the median (MoM). Odds ratios (ORs) and 95% confidence intervals (CI) were estimated.ResultsStatistically significant (p < 0.05) associations were found between inhibin A ≥ 2 MoM with fetal multicystic dysplastic kidney (MCDK) (OR = 27.5, 95% CI: 2.8–267.7) and two‐vessel cord (OR = 4.22, 95% CI:1.6–10.9); hCG of ≥ 2 MoM with MCDK (OR = 19.56, 95% CI: 1.9–196.2) and hydrocele (OR = 2.48, 95% CI: 1.3–4.6); and PAPP‐A ≥ 2.0 MoM with hydrocele (OR = 1.88, 95% CI:1.1–3.3).ConclusionIn this large prospective study, significant associations were found between several maternal serum markers and congenital anomalies. This suggests potential additional benefits to screening programs that are primarily designed to detect aneuploidy. Copyright © 2008 John Wiley & Sons, Ltd.
Simulation of chemical kinetics of elastomer crosslinking by organic peroxides
Authors: Likozar Blaž , Krajnc Matjaž 
Published: November 2008

AbstractThe chemistry of peroxide crosslinking was considered with the intention of the development of a fundamental kinetic model for the crosslinking process. The kinetics of the crosslinking of several elastomers by action of organic peroxides was studied, where dicumyl peroxide (DCP), t‐butyl peroxide (TBP), and di(2‐t‐butylperoxyisopropyl) benzene (DTBPIB) have been chosen as representative peroxides. The reaction mechanisms that have been proposed for the different steps in crosslinking chemistry were critically evaluated with the objective of developing a general description of the governing chemistry, where the mechanisms are consistent for all reaction steps in the crosslinking process. A fundamental kinetic model has been developed for the peroxide crosslinking, using population balance method that explicitly acknowledges the nature of the elastomer backbone and network, and thus reactants, intermediates and products with various reactivities. The kinetic model simulation was able to describe the complete crosslinking process including homolytic cleavage of the peroxide, beta cleavage of the oxy radical, hydrogen abstraction, addition reactions, radical coupling (crosslink formation), polymer scission and radical transfer for a wide range of compositions, and assortment of elastomers, using a single set of rate constants. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers
A novel two‐component physical gel based on interaction between poly(acrylic acid) and 6‐deoxy‐6‐amino‐β‐cyclodextrin
Authors: Sun Song , Chen Xi , Liu Jing , Yan Junlin , Fang Yu 
Published: November 2008

AbstractA two‐component physical organogel was produced by interactions of 6‐deoxy‐6‐amino‐β‐cyclodextrin (β‐CDNH2) and poly(acrylic acid). The microstructure and morphology of the gels were characterized by scanning electron microscopy, X‐ray diffraction, and Fourier transform infrared spectroscopy. It was revealed that the intermolecular hydrogen bonds between the molecules of β‐CDNH2 and the electrostatic interaction between the carboxyl groups of PAA and amino group of β‐CDNH2 were the main driving forces for the formation and maintenance of the network structures of the gel. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers
Effect of UV radiation and pro‐oxidant on PP biodegradability
Authors: Fechine G.J.M. , Rosa D.S. , Rezende M.E. , Demarquette N.R. 
Published: November 2008

AbstractThe effect of ultraviolet exposure on the biodegration of poly(propylene) without (PP) and with 0.3 (wt/wt) (PPOx) pro‐oxidant additives, produced by extrusion was studied. After UV exposure the samples were submitted to biodegradation (weight loss) in prepared soils. The samples before and after UV exposure were analyzed using differential scanning calorimetry, Fourier transform infrared spectroscopy, size exclusion chromatography, and optical microscopy. The exposure to UV radiation lead to more intense degradation of PPOx than of PP; the amount of carbonyl groups was larger for the PPOx samples than for PP, as well as the decrease in the Tm and in the molecular weight. The samples exposed to UV radiation showed some level of fragmentation after 56 days when placed in the prepared soil; the samples which were exposed to UV for 480 h presented just a small weight loss. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers
Wood‐thermoplastic composites manufactured using beetle‐killed spruce from Alaska
Authors: Yadama Vikram , Lowell Eini C. , Peterson Nels , Nicholls David 
Published: November 2008

AbstractThe primary objectives of the study were to characterize the critical properties of wood flour produced using highly deteriorated beetle‐killed spruce for wood‐plastic composite (WPC) production and evaluate important mechanical and physical properties of WPC extruded using an industry standard formulation. Chemical composition analysis indicated no significant differences in wood constituents between highly deteriorated and sound wood. Preliminary investigation with Fourier transform infrared spectroscopy (FTIR), however, indicated partial degradation or depolymerization of carbohydrate components in highly deteriorated wood compared to sound wood from green trees; effects of these changes could be seen in cell collapse and poor interaction between thermoplastic matrix and deteriorated wood fiber. Physical and mechanical properties of extruded WPCs manufactured from highly deteriorated material were comparable to WPC properties produced using pine wood flour that served as a control material. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers
Impact of cooling method and incoming sheet quality on final part surface quality in thick sheet paint film thermoformed parts
Authors: Fernholz Kedzie D. , Wykoff Rick 
Published: November 2008

AbstractThick sheet, “dry paint” film parts were thermoformed using different cooling methods and sheet temperatures to determine whether these two parameters had a direct effect on the surface quality of the final part. Although some thermoformers have claimed that applying chilled air after forming “dry paint” film parts improves the gloss of the parts, the data from this study showed that application of chilled air did not have an effect on either the parts' initial gloss or their gloss after time‐dependent hazing. The critical factor in maintaining surface quality in these parts was the maximum temperature reached by the “dry paint” film during heating. In addition, analysis of the data taken on the sheet prior to forming versus that taken on the part after forming demonstrated the importance of validating the surface quality of the as‐received sheet prior to conducting process versus appearance experiments. On the basis of these findings, a recommendation is made for incoming sheet surface quality levels for both process development studies and production applications. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers
“Barbed nanowires” from polymers via electrospinning
Authors: Holzmeister Andreas , Greiner Andreas , Wendorff Joachim H. 
Published: November 2008

AbstractElectrospinning is a highly versatile technique that allows producing fibers with diameters down to a few nanometers not only from polymers but also from metals, metal oxides, or ceramics. Fiber formation in electrospinning differs strongly from other fiber producing methods such as extrusion in that it is basically governed by self‐assembly processes induced by specific electrostatic interactions following the Earnshaw theorem of electrostatics. This allows the production of nanofibers with very peculiar shapes. Here, we report the one step fabrication of barbed nanofibers due to a particular choice of the spinning conditions. Such barbed fibers allow, among others, to control the total porosity of nanofiber nonwovens and to reduce the tendency of linear nano‐objects towards aggregation. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers
Effects of castor oil, glycol semi‐ester, and polymer concentration on the properties of waterborne polyurethane dispersions
Authors: Gao Chuanhua , Xu Xiaoming , Ni Jiani , Lin Weiwei , Zheng Qiang 
Published: November 2008

AbstractA series of waterborne polyurethane dispersions (PUDs) were synthesized using castor oil, polypropylene glycol, toluene diisocyanate, and (2E)‐4‐(2,3‐dihydroxypropoxy)‐4‐oxobut‐2‐enoic acid [glycol semi‐ester (GSE)]. These PUDs can be crosslinked spontaneously upon drying, without extra additives or processing steps. Moreover, the rheological properties, particle size, and morphology of PUDs were examined with stress‐controlled rheometer, light scattering ultrafine particle analyzer, and transmission electron microscopy. Results reveal that the particle size of PUDs mainly depends on the concentrations of castor oil, GSE, and polymer. With the increase of GSE concentration and the decrease of castor oil and polymer concentration, the particle size decreases. This can be ascribed to the decrease of the particle size of the polymer dispersion, because of the decrease of the relative size of water layer to total particle size. Furthermore, increased amount of castor oil, GSE, and polymer concentrations results in an increased viscosity of PUDs because of the increase of effective volume for the dispersed phase. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers
Dynamic reaction involving surface modified waste ground rubber tire powder/polypropylene
Authors: Lee Sung Hyo , Zhang Zhen Xiu , Xu Deng , Chung David , Oh Gil Jong , Kim Jin Kuk 
Published: November 2008

AbstractThe surface of waste ground rubber tire (WGRT) powder has been modified with by allylamine via an ultraviolet (UV) treatment. The degree of grafting of the modified‐WRGT are confirmed by the Fourier Transform Infrared spectroscopy (FTIR), scanning electron microscopy, energy dispersive X‐ray analysis, thermogravimetric analysis, and surface energy measurements. And then they incorporated into the polypropylene (PP) matrix. The effects of UV radiation time, WGRT loading, and allylamine concentration on the mechanical properties of the composites are measured. Mechanical properties are influenced as a function of UV radiation time, WGRT loading, and allylamine concentrations. The chemical interactions between grafted WGRT and PP matrix are investigated by X‐ray diffraction and FTIR. They show change of the crystallinity of the PP and the chemical reaction between WGRT and the PP. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers
Rheological study of aqueous dispersions of in situ gelable thermosensitive polymer nanogels
Authors: Wang Qin , Xu Huibi , Yang Xiangliang , Yang Yajiang 
Published: November 2008

AbstractThermosensitive poly(N‐isopropylacrylamide‐co‐acrylamide) nanogels with varied monomer compositions were prepared by precipitation polymerization. The aqueous dispersions of these thermosensitive nanogels (9 wt% of nanogel particles in phosphate‐buffered saline solution) exhibited in situ gelable characteristics. A steady‐state and dynamic rheological analysis demonstrated that the nanogel dispersions were typical pseudoplastic liquids at room temperature. The viscosity of the nanogel dispersions at a constant shear rate increased with an increase of the acrylamide content. When the temperature was increased to 37°C, the pseudoplastic liquid turned into an elastic solid, as the result of a sol–gel phase transition of the nanogel aqueous dispersion during the raise of the temperature. Dynamic temperature ramp circle curves suggest that the sol–gel transition was reversible but with a clear hysteresis. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers
Synthesis and properties of poly(sodium acrylate‐co‐2‐acryloylamino‐2‐methyl‐1‐propanesulfonic acid)/attapulgite as a salt‐resistant superabsorbent composite
Authors: Qi Xiaohua , Liu Mingzhu , Zhang Fen , Chen Zhenbin 
Published: November 2008

AbstractA novel salt‐resistant superabsorbent composite was prepared by copolymerization of partially neutralized acrylic acid, 2‐acryloylamino‐2‐methyl‐1‐propanesulfonic acid (AMPS) and attapulgite (APT). To enhance the swelling rate (SR) of the copolymer, sodium bicarbonate was used as a foaming agent in the course of copolymerization. Furthermore, for improving the properties of swollen hydrogel, such as strength, resilience and dispersion, the copolymer was surface‐crosslinked with glycerine and sodium silicate, and then the surface‐crosslinked copolymer was blended with aluminum sulfate and sodium carbonate in post treatment process. The influences of some reaction conditions, such as amount of AMPS, APT, and initiator, and neutralization degree of acrylic acid on water absorbency in 0.9 wt% NaCl aqueous solution both under atmospheric pressure (WA) and load (WAP, P ≈ 2 × 103 Pa) were investigated. In addition, the effect of them on SR was also studied. The WA and WAP of the superabsorbent composite prepared under optimal conditions in 0.9 wt% NaCl aqueous solution were 52 g·g−1 and 8 g·g−1, respectively. Besides, the SR was fast, and it could reach 0.393 mL·(g·s)−1. Moreover, the swollen hydrogel possessed excellent salt resistance, hydrogel resilience and dispersion. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers
Thermoforming triangular troughs
Authors: Lieg Katie Lynn , Giacomin A. Jeffrey 
Published: November 2008

AbstractThis analysis for thermoforming triangular troughs focuses on the manufacturing process speed and follows the method of Kershner and Giacomin for thermoforming cones. We distinguish between what happens before and after (free versus constrained forming) the melt touches the prismatic mold. Neither free nor constrained forming yields analytical solutions for the required forming time. Our analysis is restricted to the fabrication of triangular troughs from nearly Newtonian melts, the second simplest relevant problem in commercial thermoforming. The simplest relevant problem, thermoforming cones, yielded analytical solutions for the forming time. Whenever we thermoform straight edges into rigid packaging, the problem of a melt stretching into a triangular trough arises. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers