bluuebunny/crossref_metadata_2025_split huggingface dataset:
A new method for two dimensional hyperbolic problems in semi‐unbounded irregular domains
Authors: Bratsos A. G. 
Published: March 2011

AbstractAnewmethod called the full rational differential quadrature method is presented to deal with two dimensional linear and nonlinear hyperbolic problems in semi‐unbounded irregular domains. The spacial and temporal discretizations are both implemented by the rational differential quadrature method (RDQM). The RDQM, proven to be A‐stable (Chen and Tanaka, Comput Mech 28 (2002) 331–338) in the temporal discretization, is much more efficient than the finite difference schemes widely used in earlier works. In addition, the irregular boundary conditions are treated by the direct expansion method(DEM). Numerical experiments show that the present method is of high efficiency and easy to implement. © 2011Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2011
Cutaneous hematologic disorders in children
Authors: Boccara Olivia , Blanche Stéphane , de Prost Yves , Brousse Nicole , Bodemer Christine , Fraitag Sylvie 
Published: March 2011

AbstractBackgroundTo determine and list the clinical and pathological features of cutaneous hematologic diseases in childhood.ProcedureWe retrospectively analyzed the data for 51 patients up to 15 years of age, who presented with primary cutaneous hematologic disorders according to the WHO‐EORTC classification, at Necker‐Enfants Malades Hospital, Paris, France, over a 17‐year period. The cases were classified into the following diagnostic categories: CD30+ T‐cell lymphoproliferative disorders (24) all consisting of lymphomatoid papulosis (LyP, 24), lymphoblastic lymphoma (LL, 7), acute leukemias (AL, 7), mycosis fungoides (MF, 5), Epstein–Barr virus‐related lymphoproliferative disorders (EBV‐related LPD, 5), T/NK‐cell lymphoma, nasal type (1), γ/δ T‐cell lymphoma (1), and panniculitis‐like T‐cell lymphoma (1).ResultsWe encountered a majority of LyP. No secondary lymphoma was found in LyP patients with a median follow‐up of 8 years. 29% and 80% of LyP and MF patients, respectively, presented with pityriasis lichenoides chronica (PLC) before onset of disease. Owing to a frequently misleading clinicopathological presentation, MF patients were first underdiagnosed. Clinicopathological features of LL and AL were highly stereotypical, leading to the diagnosis being suspected and confirmed more promptly. In the latter patients and in EBV‐related LPD patients, skin lesions usually led to the discovery of systemic disease.ConclusionDistribution of cutaneous hematologic diseases seems to be different in adults and in children aged <15‐year old. PLC was strongly correlated with MF and LyP. Physicians must be made aware of the stereotypical clinical presentations of LL and AL to allow prompt diagnosis and treatment. Pediatr Blood Cancer 2012; 58: 226–232. © 2011 Wiley Periodicals, Inc.
Model predicted Down syndrome detection rates for nuchal translucency screening in twin pregnancies
Authors: Maymon Ron , Rosen Hadar , Baruchin Ohad , Herman Arie , Cuckle Howard 
Published: March 2011

AbstractObjectiveTo estimate the Down syndrome detection rate for nuchal translucency (NT) screening in twins when fetus‐specific risk allows for between‐fetus NT correlation.MethodsThe between‐fetus correlation coefficient of log NT, in multiples of the median (MoM), was estimated from a series of 977 unaffected twins scanned at a single centre. Results were expressed in multiples of the normal median using a curve derived from 515 unaffected singleton pregnancies at the same centre. A screening result was classified as positive if the risk for at least one fetus exceeded the cut‐off. Detection rates were estimated for a fixed 1–5% false‐positive rate, at different gestational weeks, separately for risk calculation using an algorithm which takes account of between‐fetus NT correlation or not.ResultsThe correlation coefficient in unaffected pregnancies was 0.43 (P < 0.0001) and estimated to be 0.23 and 0.11 in discordant and concordant twins. At 12 weeks of gestation, the model predicted detection rate for a 3% false‐positive rate was 68% when between‐fetus correlation is not taken into account, increasing to 73% when it is applied. Similarly, for other false‐positive rates and gestational weeks there was a predicted 4–6% increase in detection.ConclusionUsing a fetus‐specific Down syndrome risk algorithm leads to a worthwhile increase in detection. Copyright © 2011 John Wiley & Sons, Ltd.
Monoamniotic twin pregnancy discordant for lethal open cranial defect: management dilemmas
Authors: Sepulveda Waldo , Wong Amy E. , Sandoval Rodrigo , Aiello Horacio , Otaño Lucas 
Published: March 2011

AbstractObjectiveTo report the sonographic findings, prenatal courses, and management options in four cases of monoamniotic twin pregnancy complicated by a discordant, lethal open cranial vault defect.MethodsCases were collected from two Latin American fetal medicine referral centers after the sonographic detection of a monoamniotic twin pregnancy in which one fetus was structurally normal and the other had a lethal open cranial vault defect. Three abnormal fetuses had acrania‐anencephaly sequence and one had a large occipital encephalocele. The diagnosis was confirmed at referral, at which time umbilical cord entanglement was also diagnosed with color Doppler ultrasound in all cases.ResultsTwo cases were managed with selective termination, one of which required referral to a fetal surgery center abroad because this option was illegal in Chile. The other case underwent radiofrequency ablation of the fetal intra‐abdominal umbilical vessels after the corresponding ethics and legal committees approved the procedure. In both cases, the non‐anomalous twin was born after 35 weeks and had no perinatal complications. Expectant management was performed in the other two cases, resulting in the death of the normal twin at 25 weeks.ConclusionsMonoamniotic twin pregnancy discordant for severe cranial vault defect is a serious condition with a high risk of fetal demise of the structurally normal fetus. Our experience, although limited, suggests that aggressive management with selective termination of the abnormal twin and transection of its umbilical cord in these cases may prevent the demise of the structurally normal co‐twin. Copyright © 2011 John Wiley & Sons, Ltd.
Effect of the nucleophilicity and solvent on the chemical modification of flexible poly(vinyl chloride) by substitution
Authors: Kameda Tomohito , Fukuda Yuuzou , Grause Guido , Yoshioka Toshiaki 
Published: March 2011

AbstractThe chemical modification might become an alternative to the thermal degradation of waste polyvinylchloride (PVC). Therefore, the nucleophile substitution of chlorine from flexible PVC by hydroxide (OH−), thiocyanate (SCN−), azide (N3−), and iodide (I−) was investigated in ethylene glycol (EG) at 190°C. With the exception of I−, all nucleophiles used resulted in substitution yields of about 20%. However, also high elimination yields were observed. When SCN was used as the nucleophile, the substitution/elimination ratio increased with decreasing temperature. The product at 150°C contained a mixed structure of thiocyanate and isothiocyanate groups, while at 190°C, only the structure of isothiocyanate was present the product, due to the isomerization of the SCN group under the formation of NCS at elevated temperatures. The substitution and dehydrochlorination yields increased with an increasing molar SCN/Cl ratio. When EG was replaced by diethylene glycol (DEG) or triethylene glycol (TEG), the dehydrochlorination was found to proceed more rapidly. The use of a solvent with a lower polarity improved the contact between the solvent and the polymer; however, solvents with a lower polarity favor the elimination over the substitution. Therefore, the substitution–elimination ratio increased in the order EG > DEG > TEG. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers.
Effects of carbon nanotubes and their state of dispersion on the anionic polymerization of ε‐caprolactam: II. Rheology
Authors: Penu Christian , Hu Guo‐Hua , Fonteix Christian , Marchal Philippe , Choplin Lionel , Feng Lian‐Fang 
Published: March 2011

AbstractA rheometer‐reactor was designed to study the effect of the presence of multiwalled‐carbon nanotubes (MWCNT) on the kinetics of the activated anionic polymerization of ε‐caprolactam (AAPCL). The presence of the MWCNT slowed down the kinetics of the AAPCL. Moreover, the higher the MWCNT content, the more important its adverse effect on the kinetics of the AAPCL. On the other hand, the presence of the MWCNT could also adversely affect the molar mass of the resulting polyamide 6 when its content was high enough (about 1.0 wt % or higher). Possible mechanisms are discussed. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers.
Electrospinning of polyacrylonitrile solutions containing diluted sodiumthiocyanate
Authors: Moon SungCheal , Choi JaeKon , Farris Richard J. 
Published: March 2011

AbstractThe effect of NaSCN salt on the spinnability of polyacrylonitrile (PAN) solutions, its resulting morphology, mechanical property, and the flame resistance of the resulting electrospun nanofibers were studied. The intent was to develop a method to produce nanosized carbon fiber precursors with good properties. Electrospun PAN nanofibers from 9.7–9.9 wt% PAN/sodiumthiocyanate (NaSCN) (aq)/Dimethylformamide (DMF) solutions with 1.0–2.9 wt% NaSCN (aq), and 10–15 wt% PAN/DMF solutions without salt exhibited good spinnability and morphology with no beading in the range of applied voltage (18–20 kV) and take‐up velocity (9.8–12.3 m/s). The relatively high take‐up velocity produced good yarn alignment. The diameter distributions of the PAN nanofibers containing the NaSCN salt were narrower than those of the PAN/DMF nanofibers without the salt. It was determined that the maximum content of salt for production of electrospun PAN nanofibers with good morphology was below 3.8 wt% (40 wt% based on PAN). The salt concentration can positively influence on the narrow diameter distributions of the resulting electrospun fibers. Also, it could be confirmed that the salt effect on mechanical property and flame resistance of electrospun PAN nanofibers. In particular, the elongation of the PAN nanofiber with 2.9 wt% NaSCN (aq) was significantly increased as much as 186% compared with that of 10 wt% PAN nanofiber without the salt. The flame resistance and mechanical properties of the stabilized PAN nanofibers with NaSCN (aq) increased after oxidization process. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers.
Effect of filler addition and strain rate on the compressive strength of silica styrene‐butadiene rubber‐filled epoxy composites
Authors: Gope Prakash Chandra , Singh Vinay Kumar 
Published: March 2011

AbstractThe compressive failure of nanoparticle silica and styrene‐butadiene rubber (SBR)‐filled epoxy composites has been investigated. Significant increase in compressive strength, compressive modulus, work of yielding, and work of fracture was noted for the cases of composites containing low weight fraction of silica and SBR. The compressive strength is about 4–10 times of the tensile strength for composite material containing different weight percent of SBR. Increase in compressive yield strength and decrease in compressive ultimate strength have been observed with crosshead speed 0.1–100 mm/s over all weight content of SBR and silica. The material shows increased elastic region with increasing crosshead speed. This indicates that the material is expected to behave more elastically and less plastically over all the crosshead speeds. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Effects of the addition of LiCl, LiClO4, and LiCF3SO3salts on the chemical structure, density, electrical, and mechanical properties of rigid polyurethane foam composite
Authors: Verdolotti L. , Colini S. , Porta G. , Iannace S. 
Published: March 2011

AbstractThe effect of the incorporation of several lithium salts on the electrical and mechanical properties of polyurethane rigid (PUR) foams was investigated. Different amounts of lithium chloride (LiCl), lithium perchlorate (LiClO4), and lithium trifluoromethanesulfonate (LiCF3SO3) were added to the polyuretanic precursor. The salts affected the cellular microstructures and consequently the mechanical properties of the composite. Composite foams containing an amount of LiCl greater than 2 wt% showed low‐surface resistivity (∼106Ω), whereas the LiClO4and LiCF3SO3composites showed, in all range of filler percentage analyzed, high‐surface resistivity values (∼1011Ω). This behavior was related to the different interactions between PUR and lithium salts, as confirmed by FTIR/Attenuated Total Reflectance analysis. Only the LiCl was able to create a motion of the ions Li+and Cl−along the polyurethanic chains, because LiCl was completely dissociated. On the contrary, LiClO4and LiCF3SO3that affected the macromolecular structure of the polymeric network did not permit the formation of polyurethanic channels, where the ions could move, thus creating a charge motion. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Visual observation and numerical studies of polymer foaming behavior of polypropylene/carbon dioxide system in a core‐back injection molding process
Authors: Ishikawa Takeshi , Ohshima Masahiro 
Published: March 2011

AbstractThermoplastic foaming within a mold cavity was visualized as it was conducted in an 85‐ton core‐back injection‐molding machine. The core‐back molding process moved a section of the mold just after injecting a molten polymer into the cavity, quickly reducing the pressure to enhance the bubble nucleation. The foaming behavior during core‐back was observed directly through the glass windows of the mold. In the experiments, impact copolymer polypropylene was foamed with carbon dioxide. The effects of the gas concentration and the core‐back rate on bubble nucleation and growth were investigated. It was experimentally confirmed that the bubbles disappeared when the cavity was fully packed and that bubble nucleation occurred when the mold plate was moved and the cavity pressure dropped. Faster core‐back rates and higher gas concentrations increased the number of bubbles while decreasing their size. To analyze the experimental results, a bubble nucleation and growth model was employed that was based on batch foaming. The numerical results were a reasonable representation of the experiments, and this study demonstrated the applicability of the conventional free foaming model to the industrial core‐back molding process. Many aspects of the foaming in the core‐back molding aresimilar to the behaviors observed by batch foaming. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Novel Ag/C nanocable/epoxy resin composite
Authors: Liang Honglu , Yu Demei 
Published: March 2011

AbstractSilver/carbon (Ag/C) nanocables were obtained in the presence of cetyltrimethylammonium bromide (CTAB) under hydrothermal conditions in order to modify epoxy resin. Nanocable is a nanocomposite of nanowire (core) wrapped with one or more outer layers (shell). Scanning electron microscopy and energy‐dispersive X‐ray spectroscopy proved that nanocables consist of a silver nanowire core and a carbon outer shell. The (Ag/C)/epoxy composites were prepared by compounding Ag/C nanocables and epoxy resin. An investigation of the thermal, mechanical, and dielectric properties of these composites showed that the thermal stability and dielectric constant of the composites were enhanced. Interestingly, the breakdown strength of the composites at room temperature increased. Normally, breakdown strength decreases when conducting fillers are added. Fracture morphology of the (Ag/C)/epoxy composite also showed increased toughness. The relationship between the properties and microstructure of the composite was discussed in detail to explain the mechanism behind the change in material properties. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Impact of hydroquinone on thermal and electrical properties of plasticized [poly(vinyl alcohol)]0.7(LiBr)0.3(H2SO4) solid acid membrane
Authors: Badr Samy , Sheha Eslam 
Published: March 2011

AbstractA novel multi‐component system containing poly(vinyl alcohol), lithium bromide, sulfuric acid, ethylene carbonate and hydroquinone was prepared using a solution‐casting technique. The presence of hydroquinone as a reducing agent in the inorganic–organic membrane structure thus produced was thought to lead to enhanced thermal stability of the membrane. The activation energy for the thermal decomposition of the product samples increased with increasing hydroquinone doping. The ionic conductivities of the films were determined from AC impedance measurements in the temperature range 300–373 K. The maximum conductivity was found to be 1.75 × 10−3 S cm−1 for a film doped with 4 wt% hydroquinone. The results give some insight into the potential utility of the membrane as a proton‐conducting solid polymer electrolyte. Copyright © 2011 Society of Chemical Industry
Characterization of quaternized chitosan‐stabilized iron oxide nanoparticles as a novel potential magnetic resonance imaging contrast agent for cell tracking
Authors: Shen Chia‐Rui , Wu Shu‐Ting , Tsai Zei‐Tsan , Wang Jiun‐Jie , Yen Tzu‐Chen , Tsai Jin‐Sheng , Shih Mei‐Fen , Liu Chao‐Lin 
Published: March 2011

AbstractPolymer‐stabilized iron oxide nanoparticles could be used as contrast agents in magnetic resonance imaging (MRI) due to their unique superparamagnetism. Here we demonstrate a quaternized chitosan, i.e. N‐[(2‐hydroxy‐3‐trimethylammonium)propyl] chitosan chloride (HTCC), encapsulating superparamagnetic iron oxide (SPIO), with very low toxicity and less effect on cell growth. HTCC has quaternary amino groups introduced into the chitosan chain, and such modification of chitosan should render it soluble in water. Most importantly, the HTCC–SPIO thus prepared has the ability to accelerate the MRI relaxation processes of surrounding water protons, resulting in enhanced MRI contrast (R2: y = 0.1076x − 0.0092; R1: y = 0.008x − 0.0005). The iron content quantified by Prussian blue staining and MRI revealed a positive correlation between Prussian blue positive cells and the change of MRI signal intensity. Also, transmission electron microscopy and element mapping confirmed intracellular metal‐like spots as internalized iron oxide. Such findings support the use of these quaternized chitosan‐stabilized iron oxide nanoparticles as a potential MRI contrast agent for cell tracking. Copyright © 2011 Society of Chemical Industry
Characterization of high‐efficiency c‐Si CPV cells
Authors: Pravettoni Mauro , Galleano Roberto , Fucci Raffaele , Kenny Robert P. , Romano Antonio , Pellegrino Michele , Aitasalo Tuomas , Flaminio Giovanni , Privato Carlo , Zaaiman Willem , Dunlop Ewan D. 
Published: March 2011

AbstractConcentrating photovoltaics (CPV) represent an emerging market at its early stage for terrestrial application with large growth expectation and considerable research activity on new cell production has been conducting recently. In response to a fast growing demand for traceable and independent measurements on CPV cells and systems the European Solar Test Installation (ESTI) has started a research program on indoor/outdoor devices characterization. This paper focuses on two essential components of device calibration. Calibration requires traceable calibrated reference devices: for this purpose reference c‐Si cells equipped with neutral density filters of various optical densities have been used at ESTI for checking device linearity at different concentration ratios. Also essential is the implementation of common procedures and intercomparison of test results at different test laboratories. Procedures and experimental setups for concentrating c‐Si cell characterization at both ESTI and at the UTTP FOTO Laboratory of ENEA are described and results of an intercomparison are presented and discussed. Electrical performance measurements have been performed at high intensities on three different setups: a recently developed 1500× pulsed solar simulator at ESTI and two modified solar simulators capable of achieving up to 250× concentration at ENEA. Reported results show agreement within measurement uncertainties of the electrical parameters. Copyright © 2011 John Wiley & Sons, Ltd.
Inkjet printed metallizations for Cu(In1−xGax)Se2 photovoltaic cells
Authors: Hersh Peter A. , Curtis Calvin J. , van Hest Maikel F.A.M. , Kreuder John J. , Pasquarelli Robert , Miedaner Alex , Ginley David S. 
Published: March 2011

ABSTRACTThis study reports the inkjet printing of Ag front contacts on Aluminum doped Zinc Oxide (AZO)/intrinsic Zinc Oxide (i‐ZnO)/CdS/Cu(In1−xGax)Se2 (CIGS)/Mo thin film photovoltaic cells. The printed Ag contacts are being developed to replace the currently employed evaporated Ni/Al bi‐layer contacts. Inkjet deposition conditions were optimized to reduce line resistivity and reduce contact resistance to the Al:ZnO layer. Ag lines printed at a substrate temperature of 200°C showed a line resistivity of 2.06 µΩ · cm and a contact resistance to Al:ZnO of 8.2 ± 0.2 mΩ · cm2 compared to 6.93 ± 0.3 mΩ · cm2 for thermally evaporated contacts. These deposition conditions were used to deposit front contacts onto high quality CIGS thin film photovoltaic cells. The heating required to print the Ag contacts caused the performance to degrade compared to similar devices with evaporated Ni/Al contacts that were not heated. Devices with inkjet printed contacts showed 11.4% conversion efficiency compared to 14.8% with evaporated contacts. Strategies to minimize heating, which is detrimental for efficiency, during inkjet printing are proposed. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis and properties of biobased epoxy resins. part 1. Glycidylation of flavonoids by epichlorohydrin
Authors: Nouailhas Hélène , Aouf Chahinez , Le Guerneve Christine , Caillol Sylvain , Boutevin Bernard , Fulcrand Hélène 
Published: March 2011

AbstractBiobased epoxy resins were synthesized from a catechin molecule, one of the repetitive units in natural flavonoid biopolymers also named condensed tannins. The reactivity of catechin toward epichlorohydrin to form glycidyl ether derivatives was studied using two model compounds, resorcinol and 4‐methylcatechol, which represent the A and B rings of catechin, respectively. These model molecules clearly showed differences in reactivity upon glycidylation, explaining the results found with catechin monomer. The reaction products were characterized by both FTIR and NMR spectroscopy and chemical assay. The glycidyl ether of catechin (GEC) was successfully cured in various epoxy resin formulations. The GECs thermal properties showed that these new synthesized epoxy resins displayed interesting properties compared to the commercial diglycidyl ether of bisphenol A (DGEBA). For instance, when incorporated up to 50% into the DGEBA resin, GEC did not modify the glass‐transition temperature. Epoxy resins formulated with GEC had slightly lower storage moduli but induced a decrease of the swelling percentage, suggesting that GEC‐enhanced crosslinking in the epoxy resin networks. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011