bluuebunny/crossref_metadata_2025 huggingface dataset:
Facile and Efficient One‐Pot Transformation of RAFT Polymer End Groups via a Mild Aminolysis/Michael Addition Sequence
Authors: Qiu Xing‐Ping , Winnik Françoise M.
Published: September 2006

Summary: The trithiocarbonate end groups of polymers prepared by RAFT polymerization are converted into colorless and stable thioethers in a one‐pot process that combines aminolysis of the trithiocarbonate functions and Michael addition of the resulting thiols to α, β‐unsaturated carbonyl derivatives. This post polymerization procedure, which is carried out under mild conditions to near quantitative conversion, is described in the case of a telechelic poly(N‐isopropylacrylamide) sample bearing isobutylsulfanylthiocarbonylsulfanyl end groups. The chemical composition, purity, and molar masses of the modified polymers are assessed by GPC, 1H NMR spectroscopy and UV‐vis spectroscopy, which together demonstrate the efficiency of the method and confirm that the molecular weight and polydispersity of the precursor RAFT polymer are not affected by the treatment.

The facile, one pot synthesis combines the reactions of trithiocarbonate aminolysis and Michael addition of a thiol to an α, β‐unsaturated ester to transform the labile, colored thiocarbonylthio moiety into a stable, colorless thioether.

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The facile, one pot synthesis combines the reactions of trithiocarbonate aminolysis and Michael addition of a thiol to an α, β‐unsaturated ester to transform the labile, colored thiocarbonylthio moiety into a stable, colorless thioether.
Chain Architecture Dependent 3‐Dimensional Supramolecular Assembly of Rod‐Coil Molecules with a Conjugated Hexa‐p‐phenylene Rod
Authors: Park Myoung‐Hwan , Ryu Ja‐Hyoung , Lee Eunji , Han Kyung‐Hee , Chung Yeon‐Wook , Cho Byoung‐Ki , Lee Myongsoo
Published: September 2006

Summary: We have prepared hexa‐p‐phenylene based rod‐coil molecules with identical coil volume fractions, but different poly(propylene oxide) (PPO) coil architectures (linear versus dibranched), and investigated their self‐assembling behavior in the solid state by small angle X‐ray scattering (SAXS) and transmission electron microscopy (TEM) techniques. Rod‐coil molecules with a linear PPO coil showed a honeycomb‐like lamellar assembly of rod segments with hexagonally arrayed PPO coil perforations. In contrast, the rod‐coil molecules with dibranched PPO coils self‐organized into rod bundles with a body centered tetragonal symmetry surrounded by a PPO coil matrix. These results demonstrate that the steric hindrance at the rod/coil interface arising from coil architectural variation is a dominant parameter governing supramolecular rod assembly in the rod‐coil system.

TEM images and schematic illustrations of the self‐assembled structures of rod‐coil molecules with linear (left) and dibranched (right) PPO coils, respectively.

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TEM images and schematic illustrations of the self‐assembled structures of rod‐coil molecules with linear (left) and dibranched (right) PPO coils, respectively.
Synthesis of Poly(tartar amides) as Bio‐Inspired Antifreeze Additives
Authors: Yagci Yavuz E. , Antonietti Markus , Börner Hans G.
Published: September 2006

Summary: Multifunctional poly(tartar amides) have been synthesized and used as bio‐inspired antifreeze additives. It is shown that these polymers strongly interfere with the crystallization process of water in comparison to commercially available commodity polymers. While the addition of the poly(tartar amides) results in minor freezing point depression, as is shown by differential scanning calorimetry, a strong change in the ice crystal morphology is evident. Wide‐angle X‐ray scattering and optical microscopy indicate that the hexagonal structure of undisturbed ice‐crystals is oriented and partly deformed.

Light microscopy image of ice crystals at 223 K after a freezing assay with poly(tartar amides) shown at a polymer concentration of 2 wt.‐%.

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Light microscopy image of ice crystals at 223 K after a freezing assay with poly(tartar amides) shown at a polymer concentration of 2 wt.‐%.
In‐depth study of the electromagnetics of ultrahigh‐field MRI
Authors: Ibrahim Tamer S. , Mitchell Chad , Abraham Roney , Schmalbrock Petra
Published: September 2006

In this work, numerical and experimental studies of the transverse electromagnetic (TEM) resonator modes at ultrahigh‐field (UHF) MRI are performed using an in‐house finite difference time domain package at 340 MHz and using an 8 T whole‐body MRI system. The simulations utilized anatomically detailed human head mesh and a spherical head‐sized phantom, while the experiments included an electromagnetically equivalent (to simulations) phantom and in vivo human head studies. An in‐depth look at the homogeneity of the transmit‐and‐receive fields and local and global polarization of the electromagnetic waves inside the cavity of the head coil, and also the current distribution obtained on the resonator elements, is provided for several coil modes when the coil is empty and loaded. Based on the numerical and experimental results, which are in excellent agreement, an electromagnetic characterization of loading radio‐frequency (RF) head coils during a UHF MRI experiment is provided. The possibility of using the aforementioned modes for specific types of imaging application is briefly reviewed. Copyright © 2006 John Wiley & Sons, Ltd.
Improved performance of sulfonated polyarylene ethers for proton exchange membrane fuel cells
Authors: Xing D. , Kerres J.
Published: September 2006

The performances of polyarylene ethers and sulfonated polyarylene ethers having different backbone structures and sulfonated position were comparatively investigated focusing on the determination of the proton conductivity, thermal and chemical stability. The results indicated that the sulfone groups in polymer backbones are highly thermal stable. The sulfonic acid group at the meta‐sulfone position had better thermal, chemical stability and higher proton conductivity than those at the ortho‐ether and ortho‐sulfone position. The series of stability is meta‐sulfone sulfonated polyphenyl sulfone (SPSU) > ortho‐sulfone SPSU ≫ ortho‐ether SPSU. The knowledge of these parameters will lead to the synthesis of sulfonated arylene main‐chain ionomers that are optimized for application in fuel cells. Also different sulfonated polyphenyl sulfone‐4,4′‐biphenol/polybenzimidazole (SPSU‐BP/PBI) acid‐base crosslinked blend membranes have been studied. The SPSU/PBI crosslinked blend membranes had better mechanical stability than their parent membrane while maintaining good thermal stability and having suitable proton conductivity. Copyright © 2006 John Wiley & Sons, Ltd.
Gel polymer electrolyte prepared by in situ polymerization of MMA monomers in room temperature ionic liquid
Authors: Li Zhaohui , Jiang Jing , Lei Gangtie , Gao Deshu
Published: September 2006

A kind of gel polymer electrolyte was prepared by in situ polymerization of methyl methacrylate (MMA) monomers in room temperature ionic liquid (RTIL), N‐butyl‐N′‐methylimidazolium hexafluorophosphate (BMIPF6). In comparison with other gel polymer electrolytes, it reveals excellent thermal stability over 260°C. The results of differential scanning calorimetry (DSC) measurements show that its glass transition temperature decreases with an increase in the ratio of RTIL to polymer matrix. At 25°C, the gel polymer electrolyte has 0.15 × 10−3 S cm−1 of ionic conductivity when the mass ratio of BMIPF6 to MMA monomers equals 1. Analysis of FT‐IR spectra suggests that there exists a hydrogen‐bonded interaction between BMIPF6 and poly(methyl methacrylate) (PMMA) polymer matrix in the polymer electrolyte. Copyright © 2006 John Wiley & Sons, Ltd.
On the calculation of energy produced by a PV grid‐connected system
Authors: Perpiñan O. , Lorenzo E. , Castro M. A.
Published: September 2006

This study develops a proposal of method of calculation useful to estimate the energy produced by a PV grid‐connected system making use of irradiance‐domain integrals and definition of statistical moment. Validation against database of real PV plants performance data shows that acceptable energy estimation can be obtained with first to fourth statistical moments and some basic system parameters. This way, only simple calculations at the reach of pocket calculators, are enough to estimate AC energy. Copyright © 2006 John Wiley & Sons, Ltd.
Influence of temperature during phosphorus emitter diffusion from a spray‐on source in multicrystalline silicon solar cell processing
Authors: Bentzen A. , Schubert G. , Christensen J. S. , Svensson B. G. , Holt A.
Published: September 2006

We have investigated the influence of diffusion temperature during phosphorus emitter diffusion from a spray‐on source on the performance of screen‐printed multicrystalline silicon solar cells. Because of the dual diffusion mechanism present at high concentration in‐diffusion of phosphorus in silicon, applying lower diffusion temperatures for a longer duration results in significantly enhanced penetration of the low concentration tail relative to the high concentration region. Moreover, we show that the sheet resistance of in‐diffused emitters from a high concentration source depends primarily on the extension of the high concentration region, thus significantly different emitter profiles can be manufactured without altering the sheet resistance considerably. Because of the enhanced tail penetration, emitters of a specified sheet resistance diffused at reduced temperatures can result in higher fill factors of screen‐printed solar cells due to diminution of Schottky type shunts. Furthermore, emitters diffused at lower temperatures for longer durations can yield a higher gettering efficiency, resulting in increased bulk recombination lifetime, and thus a higher internal quantum efficiency at long wavelengths. The deeper tail extension of low temperature emitters, however, causes increased absorption within the highly recombinative emitter, resulting in current losses due to a lower internal quantum efficiency at short wavelengths. Copyright © 2006 John Wiley & Sons, Ltd.
Kinetics and electron spin resonance study of the radical polymerization of n‐butyl acrylate mediated by a nitroxide precursor: C‐phenyl‐N‐tert‐butylnitrone
Authors: Sciannamea Valérie , Bernard Maxime , Catala Jean‐Marie , Jérôme Robert , Detrembleur Christophe
Published: September 2006

The C‐phenyl‐N‐tert‐butylnitrone/azobisisobutyronitrile pair is able to impart control to the radical polymerization of n‐butyl acrylate as long as a two‐step process is implemented, that is, the prereaction of the nitrone and the initiator in toluene at 85 °C for 4 h followed by the addition and polymerization of n‐butyl acrylate at 110 °C. The structure of the in situ formed nitroxide has been established from kinetic and electron spin resonance data. The key parameters (the dissociation rate constant, combination rate constant, and equilibrium constant) that govern the process have been evaluated. The equilibrium constant between the dormant and active species is close to 1.6 × 10−12 mol L−1 at 110 °C. The dissociation rate constant and the activation energy for the CON bond homolysis are 1.9 × 10−3 s−1 and 122 ± 15 kJ mol−1, respectively. The rate constant of recombination between the propagating radical and the nitroxide is as high as 1.2 × 109 L mol−1 s−1. Finally, well‐defined poly(n‐butyl acrylate)‐b‐polystyrene block copolymers have been successfully prepared. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6299–6311, 2006
Polyrotaxane derivatives. I. Preparation of modified polyrotaxanes with nonionic functional groups and their solubility in organic solvents
Authors: Araki Jun , Ito Kohzo
Published: September 2006

Various polyrotaxane modification reactions, such as methylation, hydroxy propylation, tritylation, acetylation, trimethylsilylation, phenylcarbamation, dansylation, and nitration, were examined to obtain polyrotaxane derivatives, in which various functional groups were attached to cyclodextrin moieties. Although the nitrate could not be obtained because of significant degradation of the polyrotaxane under the conditions examined, other derivatives were successfully prepared under moderate conditions. The introduction of these functional groups and their degree of substitution were assessed with Fourier transform infrared and NMR spectroscopy. The polyrotaxane derivatives thus obtained were soluble in various organic solvents other than the conventional solvents (dimethyl sulfoxide and aqueous NaOH) used for the unmodified polyrotaxane. That is, the solubility of the polyrotaxane was drastically changed by the examined modification reactions. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6312–6323, 2006
Polymer having a trithiocarbonate moiety in the main chain: Application to reversible addition–fragmentation chain transfer controlled thermal and photoinduced monomer insertion polymerizations
Authors: Motokucho Suguru , Sudo Atsushi , Endo Takeshi
Published: September 2006

A polymer having a trithiocarbonate moiety in its main chain was synthesized with a cyclic, five‐membered dithiocarbonate as a building block. The trithiocarbonate in the polymer acted as a reversible addition–fragmentation chain transfer reagent to mediate a controlled insertion polymerization of styrene into the polymer main chain, giving the corresponding sequence‐ordered polymer having a well‐defined polystyrene segment in the main chain. During the polymerization, the polystyrene segment in the main chain gained its molecular weight, which maintained a linear relationship with the conversion of styrene. The insertion polymerization of styrene was induced not only thermally but also by ultraviolet irradiation. This photoinduced polymerization was well controlled by the trithiocarbonate moiety to give the corresponding polymer, whose structure was virtually the same as that obtained by the thermal polymerization. © 2006 Wiley Periodicals, Inc. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6324–6331, 2006
New heterobicationic hemicyanine dyes: Synthesis, spectroscopic properties, and photoinitiating ability
Authors: Kabatc Janina , Jędrzejewska Beata , Pączkowski Jerzy
Published: September 2006

This article describes the synthesis, spectroscopic properties, and free‐radical photoinitiation ability of new heterobicationic hemicyanine dyes. A new synthetic strategy for the preparation of unsymmetrical cyanine dyes has been developed, based on 2‐methylbenzothiazole derivative quaternization by 3‐pyridinium‐1‐bromopropane bromide and subsequent condensation of the resulting product with p‐(N,N‐dimethylamino)benzaldehyde. The tested dyes possess in one molecule two quaternary nitrogen atoms; that is, they are heterobicationic in nature. Novel hemicyanine dyes have been tested as visible‐light photoinitiators of vinyl monomer polymerization. Heterobicationic hemicyanine dyes paired with n‐butyltriphenylborate anions are very efficient photoinitiators of the free‐radical polymerization of trimethylolpropane triacrylate when irradiated with the visible emission of an argon‐ion laser. The photoinitiating abilities of the novel photoredox pairs are compared with the photoinitiation properties of their monocationic equivalent {3‐methyl‐2‐[4‐(N,N‐dimethylamino)styryl]benzothiazolium n‐butyltriphenylborate} as well as a Rose Bengal derivative (a typical triplet‐state photoinitiator). © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6345–6359, 2006
Novel polymers with a high carboxylic acid loading
Authors: Thomsen Anders D. , Malmström Eva , Hvilsted Søren
Published: September 2006

Click chemistry has been used to prepare a range of novel polymers with pendant carboxylic acid side groups. Four azido carboxylic acids, either mono‐ or difunctional and aliphatic or aromatic, have been prepared and thoroughly characterized. Extensive model reactions with 1‐ethyl‐4‐hydroxybenzene, the simplest model for poly(4‐hydroxystyrene), and the four azido carboxylic acids have been conducted to establish the proper reaction conditions and provide an analytical frame for the corresponding polymers. Poly(4‐hydroxystyrene) moieties in three different polymers—poly(4‐hydroxystyrene), poly(4‐hydroxystyrene‐co‐methyl methacrylate), and poly(4‐hydroxystyrene‐b‐styrene)—have been quantitatively transformed into oxypropynes by the use of either Williamson or Mitsunobu strategies and subsequently reacted with the azido carboxylic acids. Detailed differential scanning calorimetry investigations of all the polymers in general exhibit [when poly(4‐hydroxystyrene) is a substantial part] significant changes in the glass‐transition temperature from the polar poly(4‐hydroxystyrene) (120–130 °C) to the much less polar alkyne polymers (46–60 °C). A direct correlation between the nature of the pendant groups in the derivatized polymers and the glass‐transition temperature has emerged: the aromatic carboxylic acids give high glass‐transition temperatures (90–120 °C), and the aliphatic carboxylic acids give lower glass‐transition temperatures (50–65 °C). © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44:6360–6377, 2006
Triblock copolymer synthesis via controlled radical polymerization in solution using S‐tert‐alkyl‐N,N‐alkoxycarbonylalkyldithiocarbamate RAFT agents
Authors: Bussels Raf , Bergman‐Göttgens Christianne , Klumperman Bert , Meuldijk Jan , Koning Cor
Published: September 2006

This paper presents the solution homopolymerization, random and block copolymerization of acrylic monomers, mediated using an S‐(1,4‐phenylenebis(propane‐2,2‐diyl)) bis(N,N‐butoxycarbonylmethyldithiocarbamate) RAFT agent. Fair to good control was obtained over the solution homopolymerization of various acrylic monomers. Although inhibition periods were observed, nearly no retardation was found to occur. Satisfactory control was also obtained over the solution copolymerization of n‐butyl acrylate with methacrylic acid, mediated using this RAFT agent. Finally, triblock copolymer synthesis, starting from the macromolecular intermediates produced in the homo‐ and copolymerization experiments, was studied, and was shown to be successful. The observed relatively broad molar mass distributions could be explained by a partial decomposition of the dithiocarbamate‐based RAFT agent during synthesis and/or polymerization, for which strong indications were obtained by performing a careful MALDI‐ToF MS analysis. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6419–6434, 2006
Nitroxide‐mediated controlled statistical copolymerizations of N‐isopropylacrylamide with N‐tert‐butylacrylamide
Authors: Gibbons Orla , Carroll William M. , Aldabbagh Fawaz , Yamada Bunichiro
Published: September 2006

The copolymerization of N‐isopropylacrylamide (NIPAM) and N‐tert‐butylacrylamide (TBAM) via conventional radical polymerization and nitroxide‐mediated polymerization (NMP) with N‐tert‐butyl‐N‐[1‐diethylphosphono‐(2,2‐dimethylpropyl)]nitroxide (SG1) was investigated. The monomer reactivity ratios were determined to be 0.58 and 1.00 for NIPAM and TBAM, respectively. The reactivities were approximately the same at 120 and 60 °C in N,N‐dimethylformamide (DMF) and toluene, respectively, for the conventional copolymerizations and in DMF at 120 °C for NMP. Controlled/living characteristics for NMP were achieved with a 2,2′‐azobisisobutyronitrile/SG1 bimolecular system and a unimolecular polystyrene [poly(STY)]–SG1 macroinitiator in the presence of excess free SG1. Block copolymers of poly(N‐isopropylacrylamide‐stat‐N‐tert‐butylacrylamide) [poly(NIPAM‐stat‐TBAM)] with styrene {poly(N‐isopropylacrylamide‐stat‐N‐tert‐butylacrylamide)‐block‐polystyrene [poly(NIPAM‐stat‐TBAM)‐block‐poly(STY)]} were obtained by chain extension of either poly(NIPAM‐stat‐TBAM)–SG1 with styrene or poly(STY)–SG1 with NIPAM/TBAM. A comparison of the number‐average molecular weight calculated from the end‐group content with the number‐average molecular weight measured by gel permeation chromatography for poly(NIPAM‐stat‐TBAM)‐block‐poly(STY)–SG1 indicated that nearly all poly(NIPAM‐stat‐TBAM) chains were capped by SG1 and were thus living. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6410–6418, 2006
Design and synthesis of multifunctional glycidyl ethers that undergo frontal polymerization
Authors: Crivello James V.
Published: September 2006

An investigation of the photoactivated cationic ring‐opening frontal polymerizations of a series of alkyl glycidyl ethers has been carried out with the aid of a novel technique, optical pyrometry. With this technique, the effects of the monomer structure on the frontal behavior of these monomers have been examined. Upon irradiation with UV light, the photopolymerizations of many alkyl glycidyl ethers display a prolonged induction period at room temperature as the result of the formation of long‐lived, relatively stable secondary oxonium ions. The input of only a small amount of thermal activation energy is required to induce the further reaction of these species with a consequent autoaccelerated exothermic ring‐opening polymerization. Photoactivated frontal polymerizations have been observed for both mono‐ and polyfunctional alkyl glycidyl ether monomers. The ability of monomers to exhibit frontal behavior has been found to be related to their ability to stabilize the secondary oxonium ion intermediates through multiple hydrogen‐bonding effects to the ether groups present in the molecule. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6435–6448, 2006
Dielectric and conductivity processes in poly(ethylene terephthalate) and poly(ethylene naphthalate) homopolymers and copolymers
Authors: Psarras G. C. , Beobide A. Soto , Voyiatzis G. A. , Karahaliou P. K. , Georga S. N. , Krontiras C. A. , Sotiropoulos J.
Published: September 2006

Electrical relaxation and conductivity processes in amorphous and semicrystalline poly(ethylene terephthalate) (PET) and poly(ethylene naphthalate) (PEN) homopolymers and certain PET/PEN copolymers have been studied by means of dielectric spectroscopy. Homopolymers and copolymers able to crystallize were subjected to successive thermal runs to investigate the influence of the thermal history upon the morphology and the electrical behavior of the polymeric systems. The morphology of the untreated as well as the heat‐treated specimens was determined by means of Differential Scanning Calorimetry (DSC). All samples exhibit β‐relaxation process, due to local motions of the CO polar side groups, and α‐relaxation process associated to the glass/rubber transition. In the PEN spectrum an additional, subglass, mode was recorded, most probably attributed to cooperative motions of the naphthalene groups. Finally, the dynamic nature of the crystallization process is expressed via the over glass transition mode and the temperature dependence of dc conductivity recorded in amorphous PET, PEN, and PET/PEN (85/15) (wt/wt) samples. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3078–3092, 2006
Extended‐chain crystals in high‐pressure crystallized poly(ethylene terephthalate)/bisphenol a polycarbonate blends
Authors: Lu Jun , Huang Rui , Chen Yong , Li Liangbin
Published: September 2006

Morphologies of extended‐chain crystals with different characteristics were observed with scanning electron microscopy (SEM) in the high‐pressure crystallized polyethylene terephthalate/polycarbonate (PET/PC) blends. The crystals memorize their nucleation and growth process, which reveal an involvement of different mechanisms simultaneously. The presence of sliding diffusion during crystal thickening is indicated by a wedge shape of some crystals, while bent crystals suggest the occurrence of transesterification in the formation of the large extended‐chain crystals. The observation of two morphological features on one group of crystals shows that two mechanisms may work simultaneously. The connection between folded‐chain and extended‐chain crystals is demonstrated by the S‐shaped extended‐chain crystals as well as their direct morphological connection observed with SEM. Though transesterification plays the essential role in the formation of the large crystals, which acts in different aspects during the process, the thermodynamic driving force is the enthalpy gain associated with large crystals. This is a high‐pressure self‐assembly with a coupling between crystallization and transesterification, which may be instructive to grow such large crystals in similar polymer systems. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3148–3156, 2006
Tb(III)‐modified properties of thermosensitive core–shell microspheres
Authors: Yin Weiqing , Jiang Ling , Wang Yanjia , Huang Xiaohua
Published: September 2006

A novel functional complex with the thermosensitive, magnetic, and fluorescent properties of poly(N‐isopropylacrylamide)‐grafted poly(N‐isopropylacrylamide‐co‐styrene) (PNNS) microspheres and Tb(III), PNNS–Tb(III), has been synthesized and characterized with different techniques. When PNNS with a core–shell structure interacts with Tb(III), Tb(III) mainly bonds to oxygen of the carbonyl groups of PNNS, forming the novel PNNS–Tb(III) complex. PNNS shows antiferromagnetic behavior, whereas the PNNS–Tb(III) complex exhibits paramagnetic behavior. The saturation magnetization is approximately 50 times higher than that of PNNS. The fluorescence intensity of the PNNS–Tb(III)complex at 545 nm is enhanced as much as 223 times in comparison with that of pure Tb(III). The novel magnetic and fluorescent properties of the PNNS–Tb(III) complex may be useful in biomedicine and fluorescence systems. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3121–3127, 2006
Diagnosis of congenital CMV infection via dried blood spots
Authors: Barbi Maria , Binda Sandro , Caroppo Simona
Published: September 2006

Cytomegalovirus (CMV) infection is the most frequent congenital infection in humans and can cause permanent damage—particularly neurological—in about 20% of those infected, with or without symptoms at birth. Laboratory diagnosis is essential on account of the relatively non‐specific clinical manifestations in symptomatic newborns but also because of the high frequency of asymptomatic cases that are nevertheless at risk of lesions later in life. However, these tests need samples taken within 3 weeks of birth to distinguish congenital infection from the more common, but clinically benign, perinatal infection.

Tests for viral DNA have proved a valid means of diagnosing congenital CMV infection in neonatal blood dried on paper (DBS) widely used in screening for metabolic and genetic diseases, as an alternative to the conventional urine culture method. The DBS test is simpler, faster and less costly than viral isolation; in addition the samples can be safely stored for long periods, so diagnosis can be made even after several years. The sensitivity and specificity of the DBS test, compared to the reference method, have been reported to range between 71 and 100% and 99 and 100%, respectively, depending on the different studies and diagnostic criteria applied.

The most interesting applications reported so far involve retrospective determination of the impact of congenital CMV in sensorineural deafness, abnormalities of cortical development, neonatal cholestasis and surveys of the prevalence of this infection in various populations. The test might be useful in the future for neonatal screening with a view to treating neonates and so avoiding the damage this disease can cause. Copyright © 2006 John Wiley & Sons, Ltd.
Defining business process flexibility with the help of invariants
Authors: Regev Gil , Bider Ilia , Wegmann Alain
Published: September 2006

Enterprise survival is about maintaining an identity that is separate from other enterprises. We define flexibility as the ability to change without losing identity. The identity of an enterprise can be analyzed as a set of norms and beliefs about these norms held by its stakeholders, such as customers, employees, suppliers, and investors. Business processes and their support systems maintain invariants that are the result of compromises between the often conflicting norms and beliefs of these stakeholders. We formalize these invariants as values in a state space. Identifying a minimum set of invariants provides a basis for defining flexible processes and support systems. We illustrate the use of this framework with production business process support (BPS) systems. Copyright © 2006 John Wiley & Sons, Ltd.
A method for pricing VAR providers in the electricity markets considering voltage security
Authors: El‐Araby E. E. , Yorino Naoto , Zoka Yoshifumi
Published: September 2006

This paper presents a novel approach for procuring VAR service in a competitive market‐based environment, in which the transmission operator (TO) is supposed to run the market and enter into long‐term contracts with the successful candidates for providing the required VAR whenever called upon. The proposed method is new in that the VAR procurement problem and control problem, including load shedding, are uniformly formulated so that N‐1 security is guaranteed. Voltage stability is newly introduced into the VAR market problem in an explicit manner for normal and emergency states. The objective function is the total cost for TO, which includes the payment to VAR providers, power loss cost for normal states, and control costs for emergency states. The explicit inclusion of voltage security margin enables the TO to easily identify the critical VAR providers who should be contracted to maintain the required security level. This implies that the VAR providers in this market will be fairly remunerated on the basis of their contributions to the system security that measures the relative worth of each VAR provider. The proposed method has been applied to the IEEE 57 bus‐system to demonstrate its usefulness. © 2006 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
A heuristic‐based design of robust SMES controller taking system uncertainties into consideration
Authors: Dechanupaprittha Sanchai , Hongesombut Komsan , Watanabe Masayuki , Mitani Yasunori , Ngamroo Issarachai
Published: September 2006

In this paper, a heuristic‐based design of robust superconducting magnetic energy storage (SMES) controller is proposed taking system uncertainties into consideration. The SMES model with active and reactive power controllers is used. In addition, the effect of SMES coil current is also included in the model. The power system and the SMES unit with the designed controller are formulated as an optimization problem. The proposed objective function considers both the damping performance index and the robust stability index. In particular, the robust SMES controller is designed to enhance the system damping performance and robustness against system uncertainties such as various load and system parameter changes. The robust stability margin is guaranteed in terms of the multiplicative stability margin (MSM). In the proposed method, the robust SMES active and reactive power controllers are designed systematically by using hybrid tabu search and evolutionary programming, so that the desired damping performance and the best obtainable MSM are acquired. Finally, the designed SMES controller is examined under different situations to evaluate and confirm the effectiveness and robustness via eigenvalue analysis and nonlinear simulations. © 2006 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Thermodynamic, transport and radiation properties of high‐temperature CF3I and transient conductance of residual arc sustained in axial CF3I flow
Authors: Yokomizu Yasunobu , Suzuki Masato , Matsumura Toshiro
Published: September 2006

The present paper reports fundamental properties of CF3I under high‐temperature conditions to find out the usefulness of CF3I as an arc‐quenching gas. Firstly, particle compositions of CF3I were theoretically calculated in a temperature range from 300 to 30 000 K. Secondly, thermodynamic, transport and radiation properties of the CF3I were also obtained for pressures 0.1–1.0 MPa. Finally, the transient process of a conductance of a residual arc in CF3I was derived to compare with those in other arc‐quenching gases. In addition, an arc extinguishing capability of CF3I in a thermal re‐ignition region was derived to find out whether CF3I shows a higher capability than CO2, N2 and air. © 2006 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Quadratic function expressions and static structure characteristics in power systems
Authors: Zhou Jun , Ohsawa Yasuharu
Published: September 2006

In this study we formulate the power equations of power systems that are operating in their steady states into what we call the dtic and Hermitian power equations in terms of nodal active/reactive powers. These quadratic and Hermitian power equations are then generalized in terms of active/reactive power indices, based on which we complete three tasks: (i) deriving possible eigenvalue/singular‐value inequalities for nodal voltage stability evaluation with or without power flow computations; (ii) examining possible positive/negative definiteness, semi‐definiteness and indefiniteness of power systems that are useful in nodal voltage stability evaluation and convex/concave analysis; and (iii) scrutinizing possible convexity/concavity properties of power systems and their application. The static structure characteristics of power systems are reported here for the first time and theoretical results related to these static structural characteristics are significant in evaluating nodal voltage stability of the power systems quantitatively and qualitatively. © 2006 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
A study on the multiswing instability region using Hopf bifurcation theory considering energy threshold
Authors: Tsuji Takao , Hara Ryoichi , Oyama Tsutomu
Published: September 2006

Transient stability is treated as one of the important constraints for calculating available transfer capability (ATC), especially in Japan. Therefore, to improve the time required for ATC calculation, development of high‐speed transient stability analysis is required. For this analysis, a screening method that can recognize the serious case of fault will be greatly effective to solve the problem. Many screening methods on the first swing instability are proposed these days. However, a method based on multiswing instability has not been developed and its characteristic is not understood clearly. In this paper, the relationship between the nonlinear limit cycle and the energy function of a power system is examined using the Hopf bifurcation theory. A calculation method, which gives the critical transfer capability considering multiswing instability, is proposed. © 2006 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Electricity peak load forecasting with self‐organizing map and support vector regression
Authors: Fan Shu , Mao Chengxiong , Chen Luonan
Published: September 2006

This paper aims to study the short‐term peak load forecasting (PLF) by using Kohonen self‐organizing maps (SOM) and support vector regression (SVR). We first adopt a SOM network to cluster the input data set into several subsets in an unsupervised learning strategy. Then, several SVRs for the next day's peak load are used to fit the training data of each subset in the second stage. In the numerical experiments, data of electricity demand from the New York Independent System Operator (ISO) are used to verify the effectiveness of the prediction for the proposed method. The simulation results show that the proposed model can predict the next day's peak load with a considerably high accuracy compared with the ISO forecasts. © 2006 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
A design method of generalized minimum variance control in a multi‐rate system
Authors: Sato Takao , Inoue Akira
Published: September 2006

Generalized minimum variance control is designed in a multi‐rate system where the sampling interval of a plant output is longer than the holding interval of a control input. Because new design parameters are introduced, intersample ripples in the multi‐rate system are suppressed by weighting the variation in the control input. Furthermore, the proposed method is an extension of a conventional design method. Finally, simulation results are illustrated in order to show the effectiveness of the proposed method. © 2006 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Application of information system technologies to power control centers in a liberalized environment
Authors: Fukui Shinta , Asano Toshiaki
Published: September 2006

This paper describes the new control centers that are incorporated with information system technologies to handle precise security margins on a wide level and secure information exchange between system operators and other actors emerging in the liberalized electric power supply environment in progress. To further realize the system stress analysis by high‐speed processing, symmetric multi processor (SMP) servers are adopted through cost‐effective performance from the standpoint of investment protection. The performance improvements and observations are shown with processing time measurements according to the peculiarity of the power system analysis software packages embedded in the client‐server‐based energy management system (EMS). To cope with malicious intrusions into the cyber space through data links with outside information systems, an information exchange method using tough Internet protocol (IP) separation between information system and control system portions is also presented using a practical example, with cyber security strictly maintained among the other internal information systems in an electric power utility. © 2006 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Nonstationary optimal servo control realizing smooth switching from velocity servo to position servo—experimental study
Authors: Hara Susumu
Published: September 2006

In mechanical structures such as information precision machinery, the switching from a Velocity Servo controller to a Position Servo controller is often utilized. The author has already proposed a unified design method for both the servo controllers on the basis of a single time‐varying criterion function. Its effectiveness has been verified by numerical calculations. This letter demonstrates the effectiveness of the method experimentally. © 2006 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
How to stop time stopping
Authors: Bowman Howard , Gómez Rodolfo
Published: September 2006

Zeno-timelocks constitute a challenge for the formal verification of timed automata: they are difficult to detect, and the verification of most properties (e.g., safety) is only correct for timelock-free models. Some time ago, Tripakis proposed a syntactic check on the structure of timed automata: if a certain condition (called strong non-zenoness’ SNZ) is met by all the loops in a given automaton, then zeno-timelocks are guaranteed not to occur. Checking for SNZ is efficient, and compositional (if all components in a network of automata are strongly non-zeno, then the network is free from zeno-timelocks). Strong non-zenoness, however, is sufficient-only: There exist non-zeno specifications which are not strongly non-zeno. A TCTL formula is known that represents a sufficient-and-necessary condition for non-zenoness; unfortunately, this formula requires a demanding model-checking algorithm, and not all model-checkers are able to express it. In addition, this algorithm provides only limited diagnostic information. Here we propose a number of alternative solutions. First, we show that the compositional application of SNZ can be weakened: some networks can be guaranteed to be free from Zeno-timelocks, even if not every component is strongly non-zeno. Secondly, we present new syntactic, sufficient-only conditions that complement SNZ. Finally, we describe a sufficient-and-necessary condition that only requires a simple form of reachability analysis. Furthermore, our conditions identify the cause of zeno-timelocks directly on the model, in the form of unsafe loops. We also comment on a tool that we have developed, which implements the syntactic checks on Uppaal models. The tool is also able to derive, from those unsafe loops in a given automaton (in general, an Uppaal model representing a product automaton of a given network), the reachability formulas that characterise the occurrence of zeno-timelocks. A modified version of the carrier sense multiple access with collision detection protocol is used as a case-study.
Survival After Neoadjuvant Therapy Compared with Surgery Alone for Resectable Esophageal Cancer in a Population‐based Study
Authors: Rouvelas Ioannis , Zeng Wenyi , Lindblad Mats , Viklund Pernilla , Ye Weimin , Lagergren Jesper
Published: September 2006

Background

Esophagectomy remains the standard treatment for resectable esophageal cancer, but the cure rate is low. Neoadjuvant therapy has been tried in attempts to prolong survival and reduce tumor recurrence. The aim of this study was to assess the surgical outcomes with and without neoadjuvant treatment for resectable esophageal cancer in a population‐based setting.

Methods

All 1,155 patients treated with esophagectomy for esophageal cancer in Sweden in 1987 through 2000 with or without neoadjuvant therapy were identified and followed up in nationwide registers up to 18 October 2004. Tumor characteristics and response to neoadjuvant treatment were obtained from histopathological reports. Hazard ratios (HRs) with 95% confidence intervals (CIs) adjusted for potential confounding factors were calculated by a Cox proportional hazards regression model.

Results

Overall survival was similar in the groups with and without neoadjuvant therapy (adjusted HR 0.99, 95% CI 0.86–1.16). The 3‐year survival rates were 34.6% and 32.0%, respectively. Survival was better among the 27.6% of the neoadjuvant group with a complete histopathological response (HR 0.71, 95% CI 0.53–0.94) compared with the surgery only group. Patients without complete response to neoadjuvant therapy had seemingly poorer survival (HR 1.10, 95% CI 0.94–1.29).

Conclusions

Surgical outcomes with and without neoadjuvant therapy were equivalent. Only patients with a complete histopathological response after neoadjuvant treatment had better survival.
Treatment of Peritoneal Carcinomatosis by Cytoreductive Surgery and Intraperitoneal Hyperthermic Chemoperfusion (IHCP): Postoperative Outcome and Risk Factors for Morbidity
Authors: Roviello Franco , Marrelli Daniele , Neri Alessandro , Cerretani Daniela , de Manzoni Giovanni , Pedrazzani Corrado , Cioppa Tommaso , Nastri Giacomo , Giorgi Giorgio , Pinto Enrico
Published: September 2006

Background

Cytoreductive surgery with limited or extended peritonectomy associated with intraperitoneal hyperthermic chemoperfusion (IHCP) has been proposed for treatment of peritoneal carcinomatosis (PC) from abdominal neoplasms.

Methods

Fifty‐nine patients with PC from abdominal neoplasms underwent 61 treatments using this technique from January 2000 to August 2005. Surgical debulking, completed by partial or total peritonectomy, was performed in most cases. In 16 patients with positive peritoneal cytology without macroscopic peritoneal disease, IHCP was performed in order to prevent peritoneal recurrence. IHCP was carried out throughout the abdominopelvic cavity for 60 minutes using a closed abdomen technique. Intra‐abdominal temperature ranged between 41°C and 43°C; mitomycin C (25 mg/mq) and cisplatin (100 mg/mq) were the anticancer drugs generally used, and they were administered with a flow rate of 700–800 ml/minute.

Results

Mean hospital stay was 13 ± 7 (range 7–49) days. Postoperative complications occurred in 27 patients (44.3%); of these, major morbidity was observed in 17 (27.9%). The most frequent complications were wound infection (9 cases), grade 2 or greater hematological toxicity (5 cases), intestinal fistula (5 cases), and pleural effusion requiring drainage (5 cases). Reoperation was necessary in 5 patients (8.2%). One patient with multiorgan failure died in the postoperative period (mortality rate: 1.6%). Multivariate analysis of several variables identified completeness of cancer resection (CCR‐2/3 vs. CCR‐0/1, relative risk: 9.27) and age (relative risk: 1.06 per year) as independent predictors of postoperative morbidity. Preliminary follow‐up data indicate that survival probability may be high in patients with ovarian or colorectal cancer and low in patients with gastric cancer.

Conclusions

IHCP combined with cytoreductive surgery involves a high risk of morbidity, but postoperative complications could be resolved favorably in most cases with correct patient selection and adequate postoperative care. Tumor residual and advanced age significantly increase the risk of morbidity after this procedure.
Organizational Cultural Competency: Shifting Programs for Latino Immigrants from a Client‐Centered to a Community‐Based Orientation
Authors: Uttal Lynet
Published: September 2006

This paper discusses how the organizational cultural competency of social service agencies may be improved by shifting the philosophy of service delivery from a client‐centered to a community‐based orientation. This analysis is based on two years of fieldwork and interviews that were conducted as part of an action research project initially developed to increase the number of certified Spanish speaking Latino family childcare providers and knowledge about Latino immigrant families in the Midwest. In developing a culturally‐specific certification program in Spanish, both the Latino participants and the bilingual program director challenged the agency to consider how the social context and social location of its participants required a more holistic community approach.
Mobilizing Residents for Action: The Role of Small Wins and Strategic Supports
Authors: Foster-Fishman Pennie G. , Fitzgerald Katie , Brandell Cherise , Nowell Branda , Chavis David , Van Egeren Laurie A.
Published: September 2006

Yes we can! is a community‐building initiative funded by the W. K. Kellogg Foundation that aims to improve educational and economic outcomes in Battle Creek, Michigan by mobilizing low‐income communities and resident leaders and building their capacity to influence the decisions and policies that impact their lives. This paper describes the strategies pursued during the first phase of this initiative to foster resident mobilization by building small wins within the neighborhood. Primarily through a neighborhood‐based mini‐grant program and staff supports to encourage collective action, Yes we can! has started to increase levels of resident mobilization within the seven economically distressed neighborhoods that initially partnered with the W. K. Kellogg Foundation on this effort. The specific programming components and how they were implemented as well as the initial successes experienced are described. Lessons learned are discussed.