bluuebunny/crossref_metadata_2025_split huggingface dataset:
Single Radiation‐Induced Grafting Method for the Preparation of Two Proton‐ and Lithium Ion‐Conducting Membranes
Authors: Nasef Mohamed Mahmoud , Saidi Hamdani 
Published: August 2006

AbstractSummary: Two distinct types of polymer electrolyte membranes for conducting protons and lithium ions have been prepared by a radiation‐induced grafting method. The polymer electrolyte precursor (PVDF‐g‐PS) is obtained by the simultaneous grafting of styrene onto poly(vinylidene fluoride) (PVDF) followed by one of two specific treatments. This includes sulfonation with a chlorosulfonic acid/dichloromethane mixture to obtain proton (H+)‐conducting membranes, or activation with LiPF6/EC/DC liquid electrolyte to obtain lithium ion (Li+)‐conducting membranes. The chemical structure of the obtained electrolyte membranes is verified by FT‐IR spectroscopy. Differential scanning calorimetry is used to examine the changes in the crystallinity and the thermal properties of both electrolyte membranes during the preparation process. The thermal stability of both electrolyte membranes is also evaluated using thermal gravimetrical analysis. The obtained polymer electrolyte membranes achieve superior conductivity values: 1.61 × 10−3 S · cm−1 for Li+ and 5.95 × 10−2 S · cm−1 for H+ at room temperature at a polystyrene content of 50%. The results of this work suggest that high quality H+‐ and Li+‐conducting membranes can be obtained using a single radiation‐induced grafting method.Schematic representation of the single root for preparation of Li+‐ and H+‐conducting membranes started by radiation‐induced grafting of styrene onto a PVDF film followed by chemical treatment.magnified imageSchematic representation of the single root for preparation of Li+‐ and H+‐conducting membranes started by radiation‐induced grafting of styrene onto a PVDF film followed by chemical treatment.
Preparation and Characterization of Trialkoxysilane‐Containing Acrylic Resin/Alumina Hybrid Materials
Authors: Li Mingqi , Zhou Shuxue , You Bo , Wu Limin 
Published: August 2006

AbstractSummary: In the present study (3‐methacryloxypropyl)trimethoxysilane (MPMS) containing acrylic resin/alumina hybrid materials with various alumina contents were prepared. The effects of ethylacetoacetate (EAA) content, catalyst type, and water content during sol–gel process for alumina sols on the microstructure and properties of the hybrid materials were investigated by SAXS, AFM, DSC, TGA, and nano‐indentation tester, respectively. It was found that the hybrid materials exhibited a homogeneity and the alumina phase of the hybrids had mass fractal dimension and open structure. The thermal and mechanical properties of the hybrid materials were obviously improved when alumina was incorporated. The EAA contents, catalyst type, and water content during sol–gel process for alumina sols had obvious effects on the microstructure and properties of the hybrid materials.Typical load–displacement curves of the pure acrylic resin and hybrid materials with increasing alumina content.magnified imageTypical load–displacement curves of the pure acrylic resin and hybrid materials with increasing alumina content.
Slice‐selected LED and BPPLED: application of slice selection to DOSY
Authors: Park Ki D. , Lee Young J. 
Published: August 2006

AbstractHigh‐resolution DOSY (Diffusion‐ordered spectroscopy) is a series of 2‐dimensional and 3‐dimensional NMR techniques based on the differing diffusivity of constituent molecules in the solution state, with which the individual NMR spectrum of each component in a chemical mixture can be observed. All of the DOSY pulse sequences are derived from the spin‐echo or stimulated‐echo techniques under the effect of PFG (pulsed field gradient). One of the requirements for successful DOSY experiments and data fitting is that PFG must be uniform across the active sample volume. However, PFG, in general, is not uniform across the active sample volume in commercial high‐resolution NMR probes and this nonuniformity of PFG is known to produce systematic errors in DOSY experiments. In fact, a strong and uniform gradient field can be realized only in the central region of the gradient coil and the slice‐selection technique, widely used in Magnetic Resonance (MR) imaging, can be employed in resolving problems associated with the nonuniformity of PFG. We have developed a slice‐selection pulse block, which can be generally applied to any DOSY pulse sequence with proper care of the phase cycling and experimental parameters. We applied the slice‐selection technique to LED and BPPLED pulse sequences, which are among the most popular DOSY pulse sequences, and obtained good experimental results for a chemical mixture. Copyright © 2006 John Wiley & Sons, Ltd.
Algorithms to calculate the distribution of the longest path length of a stochastic activity network with continuous activity durations
Authors: Leemis Lawrence M. , Duggan Matthew J. , Drew John H. , Mallozzi Jeffrey A. , Connell Kerry W. 
Published: August 2006

AbstractWe develop algorithms to calculate the probability distribution of the longest path of an arbitrary stochastic activity network with continuous activity durations by three techniques: recursive Monte Carlo simulation, series‐parallel reduction, and conditioning. Examples illustrate the use of the three techniques. © 2006 Wiley Periodicals, Inc. NETWORKS, Vol. 48(3), 143–165 2006
Hyper hamiltonian laceability of Cayley graphs generated by transpositions
Authors: Araki Toru 
Published: August 2006

AbstractSuppose thatG(V0∪V1,E) is a bipartite graph with partite sets of equal size.Gis calledhyper hamiltonian laceableif (1) it has a hamiltonian path between any pair of vertices in different partite sets, and (2) for any vertexv∈Vi, there is a hamiltonian path inG−vbetween any two vertices inV1 −i. Star and bubble‐sort graphs have been considered as interconnection networks for parallel and distributed systems, and these graphs are known to be hyper hamiltonian laceable. Furthermore, it is well known that these graphs belong to the class of Cayley graphs on symmetric groups generated by a set of transpositions. In this article, we generalize those results by showing that any Cayley graph generated by transpositions is hyper hamiltonian laceable. © 2006 Wiley Periodicals, Inc. NETWORKS, Vol. 48(3), 121–124 2006
Solution methods for the p‐median problem: An annotated bibliography
Authors: Reese J. 
Published: August 2006

AbstractThe p‐median problem is a network problem that was originally designed for, and has been extensively applied to, facility location. In this bibliography, we summarize the literature on solution methods for the uncapacitated and capacitated p‐median problem on a network. © 2006 Wiley Periodicals, Inc. NETWORKS, Vol. 48(3), 125–142 2006
The marketing profession: evolution and future
Authors: Enright Michael 
Published: August 2006

Abstract
Marketing claims professional status and presents to the broader community as professional. The paper draws on previous contributions to the broader issue of professionalism and uses the examples from law, medicine and accounting to argue that the attempt has been neither completely successful nor easily demonstrable. Five criteria common to well‐known and accepted professions are developed. The paper concludes that marketing is yet to achieve professional status and asks whether such status is essential for marketers.

Copyright © 2006 John Wiley & Sons, Ltd.
Treatment for children with severe aplastic anemia and sickle cell disease in low income countries in Latin America: A report on the recent meetings of the Monza International School of Pediatric Hematology/Oncology (MISPHO): Part III
Authors: Howard Scott C. , Wilimas Judy A. , Flores Andronica , Pacheco C. , de Reyes Gladis , Machin Sergio , Svarch Eva , Navarrete Marta , Nieves Rosa , Rodriguez Hilze , Masera Giuseppe ,   The MISPHO Consortium Writing Committee
Published: August 2006

AbstractTreatment of hematologic disorders in low‐income countries (LIC) is difficult. This report summarizes treatment of sickle cell disease and aplastic anemia by pediatric hematologists from 15 LIC who participate in the Monza International School of Pediatric Hematology/Oncology (MISPHO). Patients with severe sickle cell disease were treated with low dose hydroxyurea, which safely reduced vaso‐occlusive crises. Patients with severe aplastic anemia fared poorly due to lack of availability and high cost of anti‐thymocyte globulin and cyclosporine and lack of access to stem cell transplantation. Appropriate therapy was most likely to occur in MISPHO centers with an active twinning program with a center in a high‐income country. Pediatr Blood Cancer 2007;48:598–599. © 2006 Wiley‐Liss, Inc.
Two‐dimensional Bose‐Einstein condensates in a CO2‐laser optical lattice
Authors: Cennini G. , Geckeler C. , Ritt G. , Salger T. , Weitz M. 
Published: August 2006

AbstractWe report on experiments with all‐optically produced Bose‐Einstein condensates in a mesoscopic optical lattice. By retroreflecting the radiation of a CO2‐laser operating near 10.6 μm, a lattice with spacing between sites of λ/2 ≃ 5.3 μm is realized, for which atom tunneling is negligible. Once cooled to quantum degeneracy by direct evaporative cooling in the lattice, the properties of the trapped microclouds can be studied with far field interference experiments. The microscopic atom clouds are shown to be in the two‐dimensional regime for small atom filling. The realized system has extremely long coherence times, and holds fascinating prospects for both quantum logic and the study of novel collective phenomena.
Implementation of generalized measurements with minimal disturbance on a quantum computer
Authors: Decker T. , Grassl M. 
Published: August 2006

AbstractWe consider the problem of efficiently implementing a generalized measurement on a quantum computer. Using methods from representation theory, we exploit symmetries of the states we want to identify respectively symmetries of the measurement operators. In order to allow the information to be extracted sequentially, the disturbance of the quantum state due to the measurement should be minimal.
Continuous variable entanglement between frequency modes
Authors: Glöckl O. , Andersen U.L. , Leuchs G. 
Published: August 2006

AbstractThe pairwise production of photons in nonlinear optical processes ensures entanglement to occur between two photons. E.g. when the Kerr effect is exploited, the photons are produced in different frequency modes, which are symmetric with respect to the pump frequency. Since these photons are produced into the same spatial mode, the quadrature entanglement can be witnessed only by the use of a frequency selective device which transforms the adjacent frequency modes into two different spatial modes. We use a Mach‐Zehnder interferometer with a large path length difference to separate symmetric frequency modes located 10.25 MHz from the carrier. We measure correlations of the quadrature components of 1.6 ± 0.1dB below the shot noise in the amplitude and 1.4 ± 0.1dB in the phase.
Implementation complexity of physical processes as a natural extension of computational complexity
Authors: Janzing D. 
Published: August 2006

AbstractThe theory of computational complexity in computer science investigates the time and space resources required to solve a computational problem. We show that an analogous complexity theory can be developed for quantum control problems which do not stem from computational problems. First we use the same mathematical concept to show similar lower bounds on the complexity of the following tasks: (1) Computing the boolean function “Majority”,(1) Optimal algorithmic cooling on n> two‐level systems,(2) Optimal work extraction by a heat engine acting on 2n> hot and 1 cold two‐level system,(3) Preparing appropriate n‐qubit entanglement for improving frequency standards in Ramsey spectroscopy,(4) Implementing a von‐Neumann measurement that is strongly incompatible with macroscopic observables.We describe furthermore instances of the problems “optimal heat engines” and “precise measurements” which are likely to be complex since NP‐ or even PSPACE‐complete computational problems can be reduced to them.In order to define implementation complexity also for other systems than n qubit registers we rephrase some approaches to define complexity measures using a set of available interactions and explore the complexity of analogue to digital conversion using a Jaynes Cumming interaction as an example.Furthermore we argue that, from a physical perspective of complexity, operations should only considered to be simple if there is a physically reasonable Hamiltonian that can implement them by its autonomous time evolution within a short time interval. Therefore we discuss a Hamiltonian whose natural time evolution can implement computation processes.
How to distill entanglement from a finite amount of qubits?
Authors: Probst‐Schendzielorz S. , Bschorr T. , Freyberger M. 
Published: August 2006

AbstractWe discuss a specific entanglement distillation scheme [D. Deutsch et al., Phys. Rev. Lett. 77, 2818 (1996)] under the constraint of finite samples of entangled qubit pairs. It is shown that an iterative process based on this method can be explicitly formulated. The average fidelity of this process can be strongly enhanced by introducing a conditional storing of entangled qubit pairs in each step of the iteration. We investigate the corresponding limitations on the size and the initial fidelity of the sample.
Transport dynamics of single ions in segmented microstructured Paul trap arrays
Authors: Reichle R. , Leibfried D. , Blakestad R.B. , Britton J. , Jost J.D. , Knill E. , Langer C. , Ozeri R. , Seidelin S. , Wineland D.J. 
Published: August 2006

AbstractIt was recently proposed to use small groups of trapped ions as qubit carriers in miniaturized electrode arrays that comprise a large number of individual trapping zones, between which ions could be moved [1,2] This approach might be scalable for quantum information processing with a large numbers of qubits. Processing of quantum information is achieved by transporting ions to and from separate memory and qubit manipulation zones in between quantum logic operations. The transport of ion groups in this scheme plays a major role and requires precise experimental control and fast transport times. In this paper we introduce a theoretical framework to study ion transport in external potentials that might be created by typical miniaturized Paul trap electrode arrays. In particular we discuss the relationship between classical and quantum descriptions of the transport and study the energy transfer to the oscillatory motion during near‐adiabatic transport. Based on our findings we suggest a numerical method to find electrode potentials as a function of time to optimize the local potential an ion experiences during transport. We demonstrate this method for one specific electrode geometry that should closely represent the situation encountered in realistic trap arrays.
Polymer electrolyte with ionic liquid for DSSC application
Authors: Singh Pramod K. , Kim Ki‐Il , Lee Jae‐Wook , Rhee Hee‐Woo 
Published: August 2006

AbstractWe have investigated the structural and ionic conductivity properties of the polymer electrolyte PEO:KI/I2 doped with an ionic liquid 1‐ethyl 3‐methylimidazolium thio‐cyanate (EMImSCN). Incorporation of the ionic liquid (IL) reduced the crystallinity, and enhanced the ionic conductivity. Optimized conductivity was found at 80 wt% of ionic liquid composition. This high electrical conductivity was suitable for dye sensitized solar cell (DSSC) application. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Encoding Type and Position in Peptide QSAR: Application to Peptides Binding to Class I MHC Molecule HLA‐A*0201
Authors: Pissurlenkar Raghuvir R. S. , Malde Alpeshkumar K. , Khedkar Santosh A. , Coutinho Evans C. 
Published: August 2006

AbstractVarious QSAR approaches have evolved over time to find a relationship between chemical structure and biological response by translating the information in the chemical structure into a quantitative (Hansch approach) or qualitative (Free–Wilson approach) description followed by a statistical modeling. The nature and position of every amino acid in the peptide sequence dictate its binding to the receptor. We have investigated an approach to peptide QSAR where the position and type of every amino acid in the sequence are encoded in the QSAR paradigm, and along with the principles of the Hansch (descriptor QSAR) and the Free–Wilson (binary QSAR) methodologies we were able to arrive at the optimal sequence of amino acids in the peptide. As an example, we illustrate the procedure on two datasets of nonamer peptides that bind to the class I major histocompatibility complex molecule HLA‐A*0201. The models generated have statistically significant co‐relation coefficient (r2) and predictive r2 (r2pred). The cross‐validated r2 (q2) for “descriptor QSAR” approach and the “binary QSAR” approach are in an acceptable range. The QSAR analysis is able to identify the preferential and detrimental amino acids at every position of the nonamer peptide. This QSAR formalism as applied to peptides is a simple and effective way to explain structure–activity relationships as well as to optimize the binding affinity.
Quantitative Structure–Activity Relationship Study of Some Aspartic Acid Analogues to Correlate and Predict their Sweetness Potency
Authors: Vepuri Suresh B. , Tawari Nilesh R. , Degani Mariam S. 
Published: August 2006

AbstractA series of aspartame analogues and chemically modified derivatives was evaluated for their structure–activity relationship, as artificial sweeteners using Three Dimensional Quantitative Structure–Activity Relationship (3D‐QSAR) with Genetic Functional Algorithm (GFA). A four‐term equation was developed with conventional and cross‐validated coefficients of 0.753 and 0.660, respectively. 3D‐QSAR studies of the same series were also performed by Comparative Molecular Field Analysis (CoMFA) and Comparative Molecular Similarity Indices Analysis (CoMSIA). The CoMFA model produced modest statistical significance with conventional and cross‐validated correlation coefficients of 0.768 and 0.390, respectively. The combination of steric, electrostatic, hydrophobic, and H‐bond acceptor fields in CoMSIA gave better results with conventional and cross‐validated correlation coefficients of 0.927 and 0.585, respectively. The predictive ability of 3D‐QSAR with GFA, CoMFA, and CoMSIA were determined using a test set of ten molecules giving predictive correlation coefficients of 0.375, 0.535, and 0.596, respectively, indicating better predictivity of CoMSIA compared to the other methods. Based on this information, some key features that may be used to design new sweeteners and predict their sweetness value have been identified.
QSAR Analysis of the Anticancer Activity of 2,5‐Disubstituted 9‐Aza‐Anthrapyrazoles
Authors: Slavov Svetoslav , Atanassova Mariyana , Galabov Boris 
Published: August 2006

AbstractThe anticancer activity of 35 2,5‐disubstituted 9‐Aza‐Anthrapyrazoles (9‐aza‐APs) was analyzed employing the Best Multiple Linear Regression (BMLR) as well as a heuristic method for selection of the best descriptors implemented in the CODESSA software to provide a reliable 2D‐QSAR model from a set of nearly 500 descriptors. The Chem‐X (version 2000) software was used to develop a corresponding 3D‐QSAR model. The steric and electrostatic interactions between a probe atom (H+) and a set of aligned molecules were assessed using the comparative molecular field analysis method. The results from 2D‐ and 3D‐QSAR analyses show that the anticancer activity of the studied series of 9‐aza‐APs is strongly dependent on electrostatic interactions. A binding of these derivatives to DNA has been discussed as a key factor determining the cytotoxic activity against tumor cell. The value of the maximum sum partial negative charge at the nitrogen atoms in 9‐aza‐APs influences strongly the activity of the compounds. The magnitude of these charges define the hydrogen‐bond acceptor properties of the 9‐aza‐APs. The hydrogen‐bond donor properties of the NH and OH groups in the studied series of compounds also play a key role in the binding process. The stable ring structure of the 9‐aza‐APs also appears to be an important factor for the antitumor activity of the compounds.
Fluorous TEMPO: An Efficient Mediator for the Aerobic Oxidation of Alcohols to Carbonyl Compounds
Authors: Holczknecht Orsolya , Pozzi Gianluca , Quici Silvio 
Published: August 2006

AbstractThe aerobic oxidation of alcohols to aldehydes and ketones mediated by a fluorous derivative of the stable nitroxyl radical 2,2,6,6‐Tetramethylpiperidine‐1‐oxyl (TEMPO) has been investigated. The applicability of literature protocols originally developed for TEMPO‐mediated reactions was assessed. Best results were obtained using molecular oxygen and a catalytic system combining the fluorous nitroxyl radical with Co(NO3)2/Mn(NO3)2 (Minisci's conditions). Primary and benzylic alcohols were smoothly oxidized to the corresponding aldehydes under both homogeneous and fluorous biphasic conditions, whereas the oxidation of secondary aliphatic alcohols to ketones proved more challenging, in line with the behavior of similar catalytic systems based on polymer‐supported TEMPO derivatives. The fluorous radical and related byproducts were easily removed from the reaction mixture by simple phase separation or fluorous liquid–liquid extraction, thus greatly simplifying the purification of the products. Recycling of the fluorous radical was also attempted with good results in the case of oxidation reactions requiring mild conditions.
Theoretical study of thermal rearrangements of α‐silylalcohols: Effects of substituents attached to the silicon atom on the reactions
Authors: Yu Yongming , Feng Shengyu 
Published: August 2006

AbstractTo investigate the effects of substituents attached to the silicon atom on the thermal rearrangement reactions of α‐silyl alcohols, the thermal rearrangement reactions of dimethylsilyl methanol (CH3)2SiHCH2OH and vinylsilyl methanol CH2CHSiH2CH2OH were studied by ab initio calculations at the G3 level. Geometries of various stationary points were fully optimized at the MP2(full)/6‐31G(d) and MP2(full)/6‐311G(d,p) levels, and harmonic vibrational frequencies were calculated at the same levels. The reaction paths were investigated and confirmed by intrinsic reaction coordinate (IRC) calculations at the MP2(full)/6‐31G(d) level. The results show that two dyotropic reactions could occur when (CH3)2SiHCH2OH or CH2CHSiH2CH2OH is heated. One is Brook rearrangement reaction (reaction A), and the dimethylsilyl or vinylsilyl groups migrates from carbon atom to oxygen atom coupled with a simultaneous migration of a hydrogen atom from oxygen atom to carbon atom passing through a double three‐membered ring transition state, forming dimethylmethoxylsilane (CH3)2SiHOCH3 or methoxylvinylsilane CH2CHSiH2OCH3; the other is a hydroxyl group migration (reaction B) from carbon atom to silicon atom, coupled with a simultaneous migration of a hydrogen atom from silicon atom to carbon atom, via a double three‐membered ring transition state, forming trimethylsilanol (CH3)3SiOH or methylvinylsilanol CH3SiH(OH)CHCH2. The G3 barriers of the reactions A and B were computed to be 312.8 and 241.4 kJ/mol for (CH3)2SiHCH2OH, and 317.6 and 233.7 kJ/mol for CH2CHSiH2CH2OH, respectively. On the basis of the MP2(full)/6‐31G(d) optimized parameters, vibrational frequencies, and G3 energies, the reaction rate constants k(T) and equilibrium constants K(T) were calculated using canonical variational transition state theory (CVT) with centrifugal‐dominant small‐curvature tunneling (SCT) approximation over a temperature range of 400–1800 K. The influences of methyl and vinyl groups attached to the silicon atom on reactions are discussed. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007