bluuebunny/crossref_metadata_2025_split huggingface dataset:
One‐ and two‐photon activity of cross‐conjugated photoinitiators with bathochromic shift
Authors: Heller Christian , Pucher Niklas , Seidl Bernhard , Kalinyaprak‐Icten Kadiriye , Ullrich Gerald , Kuna Ladislav , Satzinger Valentin , Schmidt Volker , Lichtenegger Helga C. , Stampfl Jürgen , Liska Robert 
Published: June 2007

AbstractIntrigued by the good performance of 1,5‐diphenylpenta‐1,4‐diyn‐3‐one (DPD) as photoinitiator for radical polymerization we prepared and investigated several donor substituted derivatives. UV‐Vis spectroscopy revealed a gradual red‐shift of λmax and higher extinction in the order of the donor capability. A methoxy‐substituted derivative (O‐DPD) exhibited significant photoinitiation activity in photo‐DSC experiments. Steady state photolysis experiments showed decreased decomposition rates with increasing donor capability. A dimethylamino derivative N‐DPD was even photostable under these conditions. Because of to the D‐π‐A‐π‐D system of these compounds two‐photon induced 3D photopolymerization experiments were performed and N‐DPD showed outstanding performance compared to often applied single photon initiators. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3280–3291, 2007
4‐methoxy‐substituted poly(triphenylamine): A p‐type polymer with highly photoluminescent and reversible oxidative electrochromic characteristics
Authors: Liou Guey‐Sheng , Yang Yi‐Lung , Chen Wen‐Chang , Su Yuhlong Oliver 
Published: June 2007

AbstractA 4‐methoxy‐substituted triphenylamine‐containing homopolymer, poly [N,N‐diphenyl‐4‐methoxyphenylamine‐4′,4′′‐diyl] (PMeOTPA), with blue light (435 nm) fluorescence quantum efficiency up to 79% was easily prepared by oxidative coupling polymerization of N,N‐diphenyl‐4‐methoxyphenylamine (MeOTPA) using FeCl3 as an oxidant. Its reversible oxidation redox couple was at 0.41 V versus Fc/Fc+ in acetonitrile solution. It exhibited good thermal stability with 10% weight‐loss temperatures above 500 °C under a nitrogen atmosphere and relatively high softening temperature (154 °C). The simply designed homopolymer revealed moderate stability of electrochromic characteristics, changing color from original pale yellowish to red, and then to black. The PMeOTPA based field effect transistor also showed p‐type characteristics with significant temperature dependence. The present study suggests that PMeOTPA is a multifunctional polymer for various optoelectronic device applications. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3292–3302, 2007
Chemical modification of polyamide‐6 by chain extension with 2,2′‐bis(2‐oxazoline)
Authors: Lu Chengxiang , Chen Tan , Zhao Xuzhong , Ren Xiancheng , Cai Xufu 
Published: June 2007

AbstractThe chain‐extension behavior of 2,2′‐bis(2‐oxazoline) (BOZ) was studied to evaluate the coupling effect on polyamide‐6 (PA6) in a Haake Rheocord mixer and an extruder. The relative torque of PA6 dramatically increased within 1–2 min, and the results were similar whether the added amount of BOZ in PA6 was the theoretical amount or twice as much at 240 °C; however, after 5 min, the coupling results showed an optimal dosage of the chain extender, a lack of which caused a deficiency of chain extension and an excess of which led to a greater blocking reaction. The final torque was 2.16 times as much as that of a control sample when the reaction temperature was 240 °C, and the added amount of BOZ in PA6 was 1.156%; at the same time, the initial carboxyl content of the chain‐extended products decreased to 40% for PA6, and this corresponded to the intrinsic viscosity of PA6 increasing to 1.636 dL/g, whereas that of the control sample was 1.384 dL/g. Furthermore, the effects of BOZ on the thermal and mechanical properties of chain‐extended PA6 were investigated. The degree of crystallinity decreased as the chain extender was added to PA6. The Izod impact strength, tensile strength, and elongation at break of the resultant products dramatically improved under wet conditions. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1976–1982, 2007
Crystallization kinetical and morphological peculiarities in binary crystalline/crystalline polymer blends
Authors: Liu Jieping , Jungnickel B.‐J. 
Published: June 2007

AbstractA survey is presented on the crystallization kinetics and the morphology of miscible crystalline/crystalline polymer blends. There are only few corresponding systems. In them, however, a number of strange kinetic and structural phenomena can be observed: (i) spherulitic crystallization of the components side‐by‐side, (ii) “interpenetrating crystallization,” (iii) “interlocking spherulitic crystallization,” and (iv) “interfilling crystallization.” Cocrystallization is forbidden for crystallographic reasons. The blend partners grow instead in their own lamellar stacks, and mixed lamellar stacks are a seldom and questionable exception. They crystallize also usually stepwise and not simultaneously. Upon step crystallization, the crystallization of the second component is determined by its redistribution with crystallization of the former. Those composition inhomogeneities are an independent issue that arises also with the development of the morphology in crystalline/amorphous blends, and a corresponding survey is yielded, too. The blend poly (vinylidene fluoride)/poly‐β‐hydroxybutyrate is a convenient model system as it can show all of these morphological and kinetic features after suitable thermal treatment. Some of them are demonstrated in the present publication. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1917–1931, 2007
Poly(propylene imine) dendrimers as plasticizers for polyvinyl chloride
Authors: Tande Brian M. , Wagner Norman J. , Kim Young H. 
Published: June 2007

AbstractFourth and fifth generation poly(propylene imine) dendrimers and methyl and benzyl functionalized copolymers of these dendrimers are solution blended with poly(vinyl chloride) (PVC). The methyl‐derivative copolymer is observed to be dispersed in PVC as judged by optical and dynamic scanning calorimetry measurements. This dispersion leads to a substantial reduction in the glass transition temperature and a commensurate plasticization effect, demonstrating that functionalized dendrimer copolymers can successfully plasticize semicrystalline polymers. This plasticization is thought to occur as a result of additional free volume from the highly branched structure of the dendrimer. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1970–1975, 2007
On the Permeability of Thermally Damaged PBX 9501
Authors: Zerkle David K. , Asay Blaine W. , Parker Gary R. , Dickson Peter M. , Smilowitz Laura B. , Henson Bryan F. 
Published: June 2007

AbstractTheoretical analysis, modeling, and simulation are used to provide insight into the development of permeability during thermal damage of the high explosive PBX 9501. In a recently published article, Terrones et al. [1] conclude that samples of PBX 9501 thermally damaged at 186 °C are not permeable to gas flow in a manner consistent with Darcy's Law. We disagree with their conclusion. We show that they have misreported data from the literature, and that their argument depends on a fluid flow model that is physically incorrect and is applied with inappropriate physical parameters.
Phase diagram of a thin Heisenberg antiferromagnetic film
Authors: Cabral Neto J. , Ricardo de Sousa J. 
Published: June 2007

AbstractWe investigate the thickness dependence of the Néel temperature of a thin quantum spin‐1/2 Heisenberg antiferromagnetic film as a function of the magnetic field on a simple cubic lattice. The Néel temperature TN(H, ℓ) is obtained by using the framework of the effective‐field theory for films consisting of ℓ = 2, 3, 5, 10 and ∞ (bulk) interacting layers. We present the phase diagram of T versus H in the whole range of the magnetic field for several values of ℓ. A continuous phase‐transition line separating the antiferromagnetic and ferromagnetic phases is observed. The critical temperature TN(H, ℓ) of the film is smaller than the corresponding bulk critical temperature $ T^{\rm b}_{\rm N} $(H) ≡ TN(H, ∞) of the infinite system, which has been analyzed recently by Bublitz Filho and de Sousa [Phys. Lett. A 323, 9 (2004)]; as ℓ is increased, TN(H, ℓ) also increases and approaches $ T^{\rm b}_{\rm N} $(H) for large values of ℓ. We have, also, studied the quantum phase transition where three critical fields were found: Hc(ℓ) = 6.224 for ℓ ≥ 3 (three‐dimensional regime), Hc(ℓ = 2) = 5.210 (intermediate regime) for ℓ = 2 and, finally, the two‐dimensional regime at ℓ = 1 with Hc(ℓ = 1) = 4.194. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Today's challenges in quantum dot materials research for tomorrow's quantum functional devices
Authors: Nötzel Richard , Anantathanasarn Sanguan , Zhou Dayong , Lippen Twan van 
Published: June 2007

AbstractSize, shape, position control, and self‐organized lateral ordering of epitaxial semiconductor quantum dot (QD) arrays are demonstrated. This constitutes the prerequisite for the ultimate control of the electronic and optical properties of man‐made semiconductor heterostructures at the single and multiple charge, spin, and photon level, including their quantum mechanical and electromagnetic interactions in view of applications such as quantum information processing and computing. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical analysis of dislocation‐related physical processes in GaN‐based epilayers
Authors: Jiang De‐Sheng , Zhao De‐Gang , Yang Hui 
Published: June 2007

AbstractIn this paper, recent progresses in optical analysis of dislocation‐related physical properties in GaN‐based epilayers are surveyed with a brief review. The influence of dislocations on both near‐band edge emission and yellow luminescence (YL) is examined either in a statistical way as a function of dislocation density or focused on individual dislocation lines with a high spatial resolution. Threading dislocations may introduce non‐radiative recombination centers and enhance YL, but their effects are affected by the structural and chemical environment. The minority carrier diffusion length may be dependent on either dislocation density or impurity doping as confirmed by the result of photovoltaic spectra. The in situ optical monitoring of the strain evolution process is employed during GaN heteroepitaxy using an AlN interlayer. A typical transition of strain from compression to tension is observed and its correlation with the reduction and inclination of threading dislocation lines is revealed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of planar photonic crystals using a quantum well infrared photodetector
Authors: Schartner S. , Golka S. , Austerer M. , Andrews A. M. , Schrenk W. , Gornik E. , Strasser G. 
Published: June 2007

AbstractA GaAs/AlGaAs quantum well infrared photodetector was combined with a deeply etched three‐fold PhC structure. This makes the detector sensitive to mid‐infrared radiation incident via the sample surface. The geometrically tunable peak responsivity is polarization independent when operated at normal incidence. Changing the angle of incidence a structure of several peaks is observed. In contrast to normal incidence illumination where the single peak can be identified as one particular PhC mode at the Γ‐point near the second order Bragg condition, the multiple peaks apparent under an arbitrary angle refer to all PhC modes which lie within the spectral responsivity of the detector. The measurement therefore represents a direct characterization procedure for band structure mapping of photonic crystals. A study of the polarization dependence shows that TM polarized waves excite even modes while TE waves couple to modes with odd symmetry. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Determination and improvement of spontaneous emission quantum efficiency in GaAs/AlGaAs heterostructures grown by molecular beam epitaxy
Authors: Wang J.‐B. , Ding D. , Johnson S. R. , Yu S.‐Q. , Zhang Y.‐H. 
Published: June 2007

AbstractThe injection and temperature dependence of the spontaneous emission quantum efficiency of molecular beam epitaxy grown GaAs/AlGaAs heterostructures is determined using excitation dependent photoluminescence (PL) measurements. Two samples are compared; one grown with Sb as a surfactant and one grown without Sb. The PL measurements were performed at temperatures from 80 to 320 K using a HeNe pump laser with powers ranging from 0.6 to 35 mW. The quantum efficiency is inferred from the power law predicted by the rate equations that links pump power and integrated PL signal. The use of Sb as surfactant improved the extrapolated peak spontaneous emission quantum efficiency from 0.970 to 0.977 at 300 K and from 0.996 to 0.998 at 180 K. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Band bending of n‐InN epilayers and exact solution of the classical Thomas–Fermi equation
Authors: Klochikhin A. A. , Davydov V. Yu. , Strashkova I. Yu. , Brunkov P. N. , Gutkin A. A. , Rudinsky M. E. , Chen H.‐Y. , Gwo S. 
Published: June 2007

AbstractThe exact solution of the Thomas–Fermi equation for a planar accumulation layer of a degenerate semiconductor is presented. The obtained results are compared with theoretical literature data. The applicability of the solution is demonstrated by using results of electrochemical capacitance–voltage measurements and photoluminescence data for n‐InN epilayers. It has been found that the difference between the electron concentrations estimated from the Hall and photoluminescence measurements is a measure of the electron content in the accumulation layer with acceptable accuracy. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Physical properties of edible films based on cassava starch as affected by the plasticizer concentration
Authors: Bergo P. V. A. , Carvalho R. A. , Sobral P. J. A. , dos Santos R. M. C. , da Silva F. B. R. , Prison J. M. , Solorza‐Feria J. , Habitante A. M. Q. B. 
Published: June 2007

AbstractThe aim of this work was to investigate the effect of glycerol contents on physical properties of cassava starch films. The films were prepared from film‐forming solutions (FFS) with 2g cassava starch/100g water and 0, 15, 30 and 45g glycerol/100g starch, and were analysed to determine its mechanical properties by tensile tests, the glass‐transition temperature (Tg) by differential scanning calorimetry (DSC) and the crystallinity by X‐ray diffraction (XRD). The infrared spectra of the films were also recorded. The resistance values of the films decreased, while those of the elasticity increased with an increase in glycerol concentration due to the plasticizer effect of glycerol, which was also observed in DSC curves. The Tg of the films prepared decreased with the glycerol content. However, for samples with 30 and 45g glycerol/100g starch, two Tg curves were observed, probably due to a phase separation phenomenon. According to the XRD diffractograms, the films with 0 and 15gglycerol/100g starch presented an amorphous character, but some tendency to show crystalline peaks were observed for films with 30 and 45g glycerol/100g starch. The results obtained with Fourier transform infrared (FTIR) corroborated these observations. Copyright © 2007 John Wiley & Sons, Ltd.
Estimation of missing observations in two‐level split‐plot designs
Authors: Almimi Ashraf A. , Kulahci Murat , Montgomery Douglas C. 
Published: June 2007

AbstractInserting estimates for the missing observations from split‐plot designs restores their balanced or orthogonal structure and alleviates the difficulties in the statistical analysis. In this article, we extend a method due to Draper and Stoneman to estimate the missing observations from unreplicated two‐level factorial and fractional factorial split‐plot (FSP and FFSP) designs. The missing observations, which can either be from the same whole plot, from different whole plots, or comprise entire whole plots, are estimated by equating to zero a number of specific contrast columns equal to the number of the missing observations. These estimates are inserted into the design table and the estimates for the remaining effects (or alias chains of effects as the case with FFSP designs) are plotted on two half‐normal plots: one for the whole‐plot effects and the other for the subplot effects. If the smaller effects do not point at the origin, then different contrast columns to some or all of the initial ones should be discarded and the plots re‐examined for bias. Using examples, we show how the method provides estimates for the missing observations that are very close to their actual values. Copyright © 2007 John Wiley & Sons, Ltd.
State‐space models for optical imaging
Authors: Myers Kary L. , Brockwell Anthony E. , Eddy William F. 
Published: June 2007

AbstractMeasurement of stimulus‐induced changes in activity in the brain is critical to the advancement of neuroscience. Scientists use a range of methods, including electrode implantation, surface (scalp) electrode placement, and optical imaging of intrinsic signals, to gather data capturing underlying signals of interest in the brain. These data are usually corrupted by artifacts, complicating interpretation of the signal; in the context of optical imaging, two primary sources of corruption are the heartbeat and respiration cycles. We introduce a new linear state‐space framework that uses the Kalman filter to remove these artifacts from optical imaging data. The method relies on a likelihood‐based analysis under the specification of a formal statistical model, and allows for corrections to the signal based on auxiliary measurements of quantities closely related to the sources of contamination, such as physiological processes. Furthermore, the likelihood‐based modeling framework allows us to perform both goodness‐of‐fit testing and formal hypothesis testing on parameters of interest. Working with data collected by our collaborators, we demonstrate the method of data collection in an optical imaging study of a cat's brain. Copyright © 2007 John Wiley & Sons, Ltd.
Retracted and replaced: Software component composition: a subdomain‐based testing foundation
Authors: Hamlet Dick 
Published: June 2007

AbstractThe following article from Software Testing, Verification and Reliability, Software component composition: a subdomain‐based testing foundation by Dick Hamlet published online on 14 June 2007 in Wiley InterScience (www.interscience.wiley.com), has been retracted by agreement between the author, the journal Editor‐in‐Chief Jeff Offutt and John Wiley & Sons, Ltd. The retraction has been agreed because the article was not ready for publication and an early version without revisions was published in error. Replacement article DOI: 10.1002/stvr.376. Copyright © 2007 John Wiley & Sons, Ltd.
[18F]FPhEP and [18F]F2PhEP, two new epibatidine‐based radioligands: Evaluation for imaging nicotinic acetylcholine receptors in baboon brain
Authors: Valette Héric , Dollé Frédéric , Saba Wadad , Roger Gaelle , Hinnen Françoise , Coulon Christine , Ottaviani Michele , Syrota André , Bottlaender Michel 
Published: June 2007

AbstractThe radioligand 2‐[18F]fluoro‐A‐85380 has been developed for imaging α4β2 nAChRs with PET. However, it has slow kinetics and a large fraction of bound activity is nondisplaceable. In an attempt to address these problems, two epibatidine‐based α4β2 nicotinic antagonists, coded FPhEP and F2PhEP, were evaluated in vivo in baboons. They were radiolabeled with fluorine‐18 from the corresponding N‐Boc‐protected bromo‐derivatives and the no‐carrier‐added K[18F]F‐Kryptofix®222 complex. Radiochemically pure [18F]FPhEP or [18F]F2PhEP was obtained in 80 min in amounts of 1.11–2.22 GBq (111–185 GBq/μmol). After injection of 215 MBq of [18F]FPhEP or [18F]F2PhEP, dynamic PET data were acquired. Thalamic radioactivity peaked at 20 min (4.9% ± 0.2% ID/100 mL tissue) for [18F]FPhEP. For [18F]F2PhEP, the peak was at 45 min (3.3% ± 0.1% ID/100 mL tissue). Regional distribution of both radiotracers was in accordance with the known distribution of nAChRs. In presaturation experiments, nicotine, cytosine, or FPhEP reduced brain radioactivity of [18F]FPhEP. In a displacement experiment with nicotine only a small amount of [18F]F2PhEP was dislodged. In spite of a moderate to high in vitro affinity, both ligands do not fulfill the widely adopted criteria for a PET radioligand. Synapse 61:764–770, 2007. © 2007 Wiley‐Liss, Inc.
Female social dominance in two Eulemur species with different social organizations
Authors: Marolf Brigitte , McElligott Alan G. , Müller Alexandra E. 
Published: June 2007

AbstractFemale social dominance is rare in mammals, but common in lemurs. We investigated social dominance in two Eulemur species; the polygynous crowned lemur (E. coronatus) and the monogamous red‐bellied lemur (E. rubriventer), using four and two social groups, respectively. We collected data on agonistic interactions and two types of affiliative behavior (grooming and maintaining spatial proximity). We used a combination of focal watches of individuals, instantaneous scan‐sampling of groups, and all‐occurrence of some behaviors in groups. We found that overall rates of agonistic interactions were higher in E. coronatus, and they also had more decided intersexual agonistic interactions than E. rubriventer. However, in both species the females won the vast majority of these agonistic interactions. E. coronatus females were groomed more often by males than vice versa, whereas no sex differences in grooming were observed in E. rubriventer. We found that males were responsible for maintaining spatial proximity in E. coronatus whereas in E. rubriventer, females were responsible. In one group of E. coronatus, the male was overweight and dominant to the female and this is the first observation of male dominance in a lemur species typically described as female dominant. We suggest that body weights in captivity be monitored for maintaining normal dominance relationships. Overall, agonistic behaviors were consistent with clear female social dominance in both E. coronatus and E. rubriventer. The affiliative behaviors also provided clear evidence for female dominance E. coronatus, but not for E. rubriventer. Zoo Biol 0: 1–14, 2007. © 2007 Wiley‐Liss, Inc.
Quantitative determination of medium chain triglycerides in infant formula by reverse phase HPLC
Authors: Lee Theresa W. 
Published: June 2007

AbstractTwo methods were developed for the separation of medium chain triglycerides (MCT) using reverse phase HPLC. Both methods employed a C18 microbond HPLC column as the stationary phase and an isocratic solvent system. The first method described consists of acetonitrile/acetone as the mobile phase with a differential refractometer as the detector. In the second method, acetonitrile/water was used as the mobile phase and a UV detector at 210 nm. Trinonanoin was used as the internal standard for quantitative determination. This method is suitable for milk‐, whey‐ and soy protein‐based matrices. With minor modification, it is applicable to MCT levels ranging from 10 to 50% of total fat.
Tocopherol content in oil palm leaflet
Authors: Gapor Ab. , Kato A. , Ong A. S. H. 
Published: June 2007

AbstractMature oil palm leaflets are readily available as byproducts from oil palm plantations.α‐Tocopherol and chlorophyll contents of palm leaflets obtained from oil palm trees of different ages and varieties were determined.α‐Tocopherol and chlorophyll contents were in the range of 0.14–0.28% and 0.23–0.31%, respectively, in palm leaflets on wet bases. The molar ratios ofα‐tocopherol to chlorophyll were 0.78–2.37.