bluuebunny/crossref_metadata_2025_split huggingface dataset:
Formation of Polyolefin‐block‐polystyrene Block Copolymers on Phenoxyimine Catalysts
Authors: Weiser Marc‐Stephan , Mülhaupt Rolf 
Published: July 2006

AbstractSummary: PE‐block‐PS and P(E‐co‐P)‐block‐PS block copolymers were synthesised via sequential monomer addition during homogeneous polymerisation on various phenoxyimine catalysts. One phenoxyimine catalyst was tailored to produce high molecular weight block copolymers containing both, polyolefin and polystyrene segments. According to chromatographic analysis and TEM morphology studies, blends of block copolymers and PE homopolymers [or P(E‐co‐P), respectively] were formed. The direct olefin/styrene block copolymer synthesis on phenoxyimine catalysts represents an attractive, new one‐pot route to styrenic block copolymers which are commercially prepared by anionic styrene/diene block copolymerisation followed by hydrogenation.
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Comparison study of multi‐attribute decision analytic software
Authors: French Simon , Xu Dong‐Ling 
Published: July 2006

AbstractIn this paper, we discuss the functionality and interfaces of five MCDM software packages. We recognize that no single package is appropriate for all decision contexts and processes. Thus our emphasis is not so much to compare the functionality of the packages per se, but to consider their fit with different decision making processes. In doing so, we hope to provide potential users with guidance on selecting a package that is more compatible with their needs. Moreover, we reflect on the further functionality which we would believe should be developed and included in MCDM packages. Copyright © 2006 John Wiley & Sons, Ltd.
On interactive multiobjective optimization with NIMBUS® in chemical process design
Authors: Hakanen Jussi , Miettinen Kaisa , Mäkelä Marko M. , Manninen Jussi 
Published: July 2006

AbstractWe study multiobjective optimization problems arising from chemical process simulation. The interactive multiobjective optimization method NIMBUS®, developed at the University of Jyväskylä, is combined with the BALAS® process simulator, developed at the VTT Technical Research Center of Finland, in order to provide a new interactive tool for designing chemical processes. Continuous interaction between the method and the designer provides a new efficient approach to explore Pareto optimal solutions and helps the designer to learn about the behaviour of the process. As an example of how the new tool can be used, we report the results of applying it in a heat recovery system design problem related to the process water system of a paper mill. Copyright © 2006 John Wiley & Sons, Ltd.
Dispersion of compound muscle action potential in hereditary neuropathies and chronic inflammatory demyelinating polyneuropathy
Authors: Stanton Michael , Pannoni Valerie , Lewis Richard A. , Logigian Eric L. , Naguib Demian , Shy Michael E. , Cleland James , Herrmann David N. 
Published: July 2006

AbstractDistal compound muscle action potential (DCMAP) dispersion, defined as a DCMAP duration ≥9 ms, and proximal‐distal (P‐D) CMAP dispersion are considered useful in the electrodiagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP). Distal and P‐D CMAP dispersion have not been fully studied in hereditary neuropathies, and it is not known whether these measures distinguish hereditary from acquired demyelination. We compared DCMAP duration and P‐D CMAP dispersion in 91 genetically characterized hereditary neuropathies and 33 subjects with CIDP. DCMAP dispersion was more frequent in nerves affected by CIDP (41.5%) than in Charcot–Marie–Tooth disease (CMT)1A (24.4%), CMT1B (7.4%), hereditary neuropathy with liability to pressure palsies (HNPP) (10.5%), or CMTX (9.8%). P‐D CMAP dispersion was more frequent in CIDP (27.7% of nerves) than in hereditary neuropathies (16.3%) when applying American Academy of Neurology (AAN) criteria; however, its frequency was similar in CIDP and the hereditary neuropathies using the more restrictive criteria of the American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM). Although dispersion is more common in CIDP than in the hereditary neuropathies, DCMAP and P‐D dispersion occur in at least one motor nerve in a significant proportion of hereditary neuropathies, and cannot be used in isolation to distinguish acquired from hereditary demyelination. Muscle Nerve, 2006
Array CGH profiling of favourable histology Wilms tumours reveals novel gains and losses associated with relapse
Authors: Natrajan R , Williams RD , Hing SN , Mackay A , Reis‐Filho JS , Fenwick K , Iravani M , Valgeirsson H , Grigoriadis A , Langford CF , Dovey O , Gregory SG , Weber BL , Ashworth A , Grundy PE , Pritchard‐Jones K , Jones C 
Published: July 2006

AbstractDespite the excellent survival of Wilms tumour patients treated with multimodality therapy, approximately 15% will suffer from tumour relapse, where response rates are markedly reduced. We have carried out microarray‐based comparative genomic hybridisation on a series of 76 Wilms tumour samples, enriched for cases which recurred, to identify changes in DNA copy number associated with clinical outcome. Using 1Mb‐spaced genome‐wide BAC arrays, the most significantly different genomic changes between favourable histology tumours that did (n = 37), and did not (n = 39), subsequently relapse were gains on 1q, and novel deletions at 12q24 and 18q21. Further relapse‐associated loci included losses at 1q32.1, 2q36.3‐2q37.1, and gain at 13q31. 1q gains correlated strongly with loss of 1p and/or 16q. In 3 of 11 cases with concurrent 1p−/1q+, a breakpoint was identified at 1p13. Multiple low‐level sub‐megabase gains along the length of 1q were identified using chromosome 1 tiling‐path arrays. One such recurrent region at 1q22‐q23.1 included candidate genes RAB25, NES, CRABP2, HDGF and NTRK1, which were screened for mRNA expression using quantitative RT‐PCR. These data provide a high‐resolution catalogue of genomic copy number changes in relapsing favourable histology Wilms tumours. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Direct quantification of fetal cells in maternal blood by real‐time PCR
Authors: Zhong Xiao Yan , Holzgreve Wolfgang , Hahn Sinuhe 
Published: July 2006

AbstractBackgroundFetal cells in maternal blood still present an enticing alternative for the development of a safe and efficacious non‐invasive method for prenatal diagnosis. However, most enrichment methods are very tedious and have failed to realise this long sought after goal. We developed a simple, robust TaqMan real‐time PCR assay to directly quantify male fetal cells in maternal blood using the multi‐copy DYS14, without the need for any additional enrichment procedure.MethodsThe sensitivity of the DYS14 assay was evaluated by using female genomic DNA spiked with male DNA or male cells. The specificity of the DYS14 assay was evaluated by examining 40 adult blood samples and 44 maternal blood samples from pregnant women with known fetal gender. Direct quantification of fetal cells in maternal blood was performed in 14 of the maternal blood samples by the DYS14 assay. The results were compared to those by SRY assay.ResultsThe sensitivity of DYS14 PCR assay was found to be higher than that of SRY assay for the detection of fetal cells. The number of fetal cells in maternal blood did not exceed 2/mL blood. The presence of cell‐free fetal DNA in maternal blood could lead to erroneous quantification of fetal cell DNA. The number of fetal cells detected in blood cell pellets, which had been unwashed to remove the cell‐free fetal DNA, was indeed significantly higher than those in extensively washed samples.ConclusionsWe quantified the fetal cells in maternal blood without fetal cell enrichment procedures by TaqMan real‐time PCR for a multi‐copy DYS14 locus. Our assay is sensitive and also suitable for automation, and may be a useful tool for the determination of fetal‐maternal cell trafficking, such as microchimerism. Copyright © 2006 John Wiley & Sons, Ltd.
Extensional flow mixer for polymer nanocomposites
Authors: Tokihisa M. , Yakemoto K. , Sakai T. , Utracki L.A. , Sepehr M. , Li J. , Simard Y. 
Published: July 2006

AbstractThe extensional flow mixer (EFM) has been used in industry, for e.g., homogenization of reactor products, polymer blending, incorporation of plasticizer, etc. Recently, several laboratories attempted to use EFM for dispersing organoclay in a molten polymer. Thus, usually EFM was mounted on a twin‐screw extruder equipped with a gear pump. The use of EFM resulted in improved dispersion and performance—more significant in polyamide or thermoplastic polyester—and marginal in a polyolefin or polystyrene. Recently, to improve EFM efficiency, the commercial EFM‐3 was modified by redesigning the convergent–divergent plates that engender the extensional flow. The two mixers, EFM‐3 and the new EFM‐N, were evaluated using a single‐screw extruder. Two systems were examined: (1) polyamide‐6 (PA‐6) with Cloisite®‐15A (C15A) and (2) polypropylene with maleated‐PP and C15A. The compounded samples were injection‐molded, and then tested for the degree of dispersion and mechanical performance. The results showed superiority of EFM‐N. Compounding PA‐6 with C15A in a single‐screw extruder with EFM‐N exfoliated the organoclay, producing polymeric nanocomposites with high performance, comparable or better than that of a commercial nanocomposite produced by polycondensation of ϵ‐caprolactam in the presence of clay, preintercalated with reactive cations. POLYM. ENG. SCI. 46:1040–1050, 2006. © 2006 Society of Plastics Engineers
Single‐crystal growth of 4‐hydroxy‐3‐methoxy benzaldehyde by the Bridgman technique and its characterization
Authors: Kannan V. , Jayaprakasan M. , Bairava Ganesh R. , Ramasamy P. 
Published: July 2006

AbstractSingle‐crystal growth of 4‐hydroxy‐3‐methoxy benzaldehyde (vanillin), an excellent molecular nonlinear optical (NLO) material, from the melt using the Bridgman technique is reported for the first time. Differential thermal analysis experiments indicated that the substance melts congruently at 81 °C. A precise temperature profile plot of the resistive furnace used was measured using a simple PC‐based time–temperature data logging system. Powder X‐ray diffraction analysis of the grown crystal revealed the crystal belongs to the monoclinic system. Fourier transform infrared spectra were used to assign various modes and identify the functional groups. The crystal exhibited a wide window of transmission unlike other organic NLO crystals. The optical second harmonic generation conversion efficiency of vanillin was determined using the Kurtz powder technique. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Measurement of external stress on bulk GaN
Authors: Kim J. , Baik K. , Park C. , Cho S. , Pearton S. J. , Ren F. 
Published: July 2006

AbstractWe report on the measurement of stress in bulk, free‐standing GaN templates under external bending using micro‐Raman scattering. A 488 nm Ar‐ion laser beam was scanned in a cross‐sectional geometry across the GaN template held under external stress conditions. Our experiment showed that the top half of the bulk GaN was under ∼73 MPa of tensile stress while the bottom half of the GaN template was under 40 MPa of compressive stress when bent by a press screw. This data is very helpful to understand both the optical and mechanical properties of bulk GaN and for calibrating and optimizing GaN‐based pressure sensors. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Uniaxial stress study of the Cu–H complex in ZnO
Authors: Lavrov E. V. , Weber J. 
Published: July 2006

AbstractThe influence of uniaxial stress on the vibrational mode of the Cu–H complex at 3192 cm–1 in ZnO is studied. It is shown that the split patterns are consistent with the stretching mode of a bond‐centered hydrogen located in the basal plane between substitutional Cu and O. Quantitative analysis of the stress effects reveals two low energy modes with frequencies of 25 and 49 cm–1. Upon substituting deuterium for hydrogen they shift to 22 and 36 cm–1, respectively. The origin of the low energy modes is discussed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Extrinsic defect structure of RE3Al5O12 garnets
Authors: Stanek C. R. , McClellan K. J. , Levy M. R. , Grimes R. W. 
Published: July 2006

AbstractRE3Al5O12 garnets (where RE represents rare earth atoms Lu–Gd and Y) are technologically important, particularly for optical applications. However, the performance of these materials suffers from the existence of point defects, which are responsible for both delayed and reduced light output in Ce:Y3Al5O12 (Ce:YAG) scintillators. The complex garnet crystal structure prevents a straightforward description of the defects responsible for decreased performance. In this paper, we employ atomistic simulation techniques to reveal nonintuitive features of the extrinsic defect structure. Specifically: Me2+ dopants (ranging in ionic size from Mg2+–Ba2+) are predicted to reside on RE sites with oxygen vacancies as charge compensating defects and Me4+ dopants (from Ti4+–Pb4+) reside on both RE and Al sites and are predicted to be charge compensated by RE vacancies. These results predict the defects resulting from common Me2+ impurities, as well as explain why Me4+ doping is not effective in improving RE3Al5O12 scintillator performance.magnified imageThe predicted extrinsic defects in RE3Al5O12 associated with Me2+ (bottom left) and Me4+ (upper right) doping. Small and large grey atoms represent Al and RE lattice atoms respectively. Oxygen atoms are not shown. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Band structure of functional oxides by screened exchange and the weighted density approximation
Authors: Robertson J. , Xiong K. , Clark S. J. 
Published: July 2006

AbstractMost ab‐initio calculations of the electronic structure use the local density approximation, which gives good structural data but severely under‐estimates the band gaps of semiconductors and insulators. This paper presents calculations of the band structures of some important oxide semiconductors and insulators, using the screened exchange method and the weighted density approximation, which give improved band gaps. The methods are tested on diamond, Si, Ge, MgO, Al2O3, and SiO2 and the main interest is for HfO2, ZrO2, SrTiO3, PbTiO3, LaAlO3, La2O3, ZrSiO4, SnO2, CuAlO2, and SrCu2O2. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Resistance switching in perovskite thin films
Authors: Ignatiev A. , Wu N. J. , Chen X. , Liu S. Q. , Papagianni C. , Strozier J. 
Published: July 2006

AbstractRecent research on the resistance switching effect in manganite oxide based electric‐pulse‐induced resistance (EPIR) devices is being reviewed. The EPIR effect encompasses the reversible change of resistance of a thin oxide film such as Pr1–x Cax MnO3 (PCMO) under the application of short, low voltage pulses. Two groups of EPIR devices have been investigated: one with the PCMO layer sandwiched between a top and a bottom electrode; the other with both electrodes on top of the PCMO thin films, which were grown on insulating substrates. I –V switching characteristics, electric pulse switching hysteresis, as well as the dynamic resistance during nano second switching pulses of the EPIR devices were measured. Temperature studies showed similar activation energies for both high and low resistance states. Resistance profile microanalysis showed resistance switching both in the interface regions of the oxide film near the electrode, as well as in the bulk of PCMO film with the major resistance change from the interface regions. The resistance switching mechanism is discussed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Carrier‐mediated stabilization of ferromagnetism in semiconductors: holes and electrons
Authors: Dalpian G. M. , Wei Su‐Huai 
Published: July 2006

AbstractBand structure models are proposed to help understand carrier‐induced ferromagnetism in diluted magnetic semiconductors. We describe both hole‐ and electron‐mediated ferromagnetism. For hole‐mediated ferromagnetism, we show that there are two distinct mechanisms related to the stabilization of ferromagnetism. The difference between them is related to the position of the impurity d levels with respect to the valence band edge. If the impurity states are in the band gap, ferromagnetism can be explained by double exchange, which is related to the direct coupling between the impurity levels, whereas if the filled impurity states are below the VBM, ferromagnetism can be explained by the Zener model, which is related to the coupling between the impurity d levels and the host valence p states. In both cases, it is necessary to have holes, either free or localized, to stabilize the ferromagnetism. Our model successfully explains the ground state magnetic configuration of CdMnTe, GaMnAs, ZnMnO, and GaMnN. An extension of our model can also successfully explain the intriguing behavior of GaMnN. We show that at low Mn concentration, its ground state is FM, although AFM can be stabilized by increasing the Mn concentration, applying pressure, or by compensating the holes. For electron‐mediated ferromagnetism, we point out that it is necessary first to increase the exchange splitting of the conduction band. This can be done by reducing the symmetry of the system, by quantum confinement, or by changing the magnetic impurities from transition metals to rare earths. Our results also clarify some issues related to experimental works, such as the negative exchange splitting of the conduction band in GaMnAs quantum wells and the stabilization of ferromagnetism in GaGdN. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electronic structure of Pd‐covered (10,0) carbon nanotube
Authors: Zhu Wenguang , Kaxiras Efthimios 
Published: July 2006

AbstractWe report a first‐principles study on the electronic structure of a semiconducting (10,0) single‐wall carbon nanotube fully covered by Pd electrode, which closely resembles experimental setups. The equilibrium structure, charge transfer effects, electrostatic potentials, and the density of states are studied in detail, in order to establish whether a barrier exists or not between the natotube and the metal contact. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparison between color Doppler cineloop‐ and conventional spectral Doppler‐derived maximum velocity and flow in the umbilical vein
Authors: Gerada M. , Struijk P. C. , Stewart P. A. , Guerriero S. , Melis G. B. , Wladimiroff J. W. 
Published: July 2006

AbstractObjectiveTo compare the umbilical venous flow velocity derived from color Doppler cineloop recordings with that derived from conventional spectral Doppler in normal pregnancies.MethodIn 18 uncomplicated pregnancies between 19 and 39 weeks' gestation, color Doppler was used to find the maximum velocity in the cross‐sectional vessel area of a free‐floating loop of the umbilical vein. The maximum velocity was determined using the software tool HDI_Lab (Philips Medical Systems) after tracing the vessel area of interest. Conventional spectral Doppler was then used to determine the maximum velocity with the High‐Q machine option. The cross‐sectional area of the umbilical vein was determined using B‐mode imaging and was subsequently used to determine the umbilical volume flow from both Doppler methods. Assuming a parabolic flow profile in the umbilical vein, the mean velocity is equal to half the maximum velocity. The fetal weight was estimated from fetal biometry using the four‐parameter Hadlock formula.ResultsMaximum velocity was significantly (P = 0.003) higher with color Doppler cineloop (14.3 ± 2.5 cm/s) compared with spectral Doppler (12.7 ± 3.2 cm/s). Therefore, using the same cross‐sectional area for both methods, the umbilical blood flow was significantly higher (P = 0.001) with color Doppler cineloop (127.9 ± 59.0 mL/min) than it was with spectral Doppler (112.8 ± 54.1 mL/min). The umbilical blood flow expressed as volume flow per kg fetal weight was significantly (P = 0.01) higher with color Doppler cineloop (126.0 ± 57.0 mL/min/kg) than it was with spectral Doppler (115.0 ± 53.0 mL/min/kg).ConclusionsUmbilical venous flow velocity derived from color Doppler cineloops is approximately 10% higher than that derived from spectral Doppler‐derived velocity. The reduced angle dependence of the color Doppler cineloop technique and the large sampling area of the cross‐sectional vessel should allow better determination of the correct maximum velocity in the umbilical vein. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Performance analysis of the forward link cdma2000 1xEV‐DO evolution for multirate services in cellular wireless system
Authors: Matalgah Mustafa M. , Radaydeh Redha M. , Ismail Mahmoud H. 
Published: July 2006

AbstractIn this paper, we propose a combined analytical and simulation framework for performance evaluation of the forward link in the cdma2000 evolution for data only (1xEV‐DO) cellular systems with throughput and spectral efficiency being used as performance metrics. A closed form expression for the aggregate average throughput is derived in terms of system‐dependent parameters and a discrete random process that reflects the stochastic behavior of the transmission channel. The random process is expressed in terms of the cumulative distribution function (CDF) of the users signal‐to‐interference‐plus‐noise ratio (SINR). Quantitative results for throughput and spectral efficiency are presented for a variety of users distribution models, base station antenna types and frequency reuse factors for the cases of sectorized and non‐sectorized cells. Furthermore, we study the impact of the cell radius on the system performance. Copyright © 2006 John Wiley & Sons, Ltd.
Performance of coded DS‐CDMA system using reduced rank MMSE receiver in Rayleigh fading channels
Authors: Almutairi Ali F. , GabAllah Mohammed M. 
Published: July 2006

AbstractThis paper examines the performance of a reduced rank minimum mean square error (MMSE) receiver‐based direct sequence code division multiple access (DS‐CDMA) system. For such system, when a large processing gain is employed, substantial time is consumed in computing the filter tap weights. Many schemes for reducing the complexity of the MMSE have been proposed in recent years. In this paper, computational complexity reduction of the MMSE receiver is achieved by using the K‐mean classification algorithm. The performance of the uncoded and coded systems are investigated for the full rank MMSE receiver and reduced rank MMSE receiver and results are compared in terms of bit error rate at different loading levels in both AWGN and fading channels. A system with the matched filter (MF) receiver is also presented for the purpose of comparison and an analytical pair‐wise error bound for the coded system is derived. In the adaptive implementation of the receivers, results show that good performance is achieved for the reduced rank receiver when compared to the full rank receiver in both coded and uncoded systems, while in the optimum implementation of the tap weights, the reduced dimension receiver performance experiences degradation when compared to the full rank scheme. Over the band‐limited channels considered, results for the reduced rank receiver also reiterate the fact that higher code rates tend to yield lower BER than that of low rate codes. Copyright © 2006 John Wiley & Sons, Ltd.