bluuebunny/crossref_metadata_2025_split huggingface dataset:
An efficient architecture for Bandwidth Brokers in DiffServ networks
Authors: Bouras Ch. , Stamos K. 
Published: February 2007

AbstractIn this article we examine the architecture of an entity used for automatic management and provisioning of resources for DiffServ networks. We examine the existing literature and implementations in this area, focusing on the design choices made, and we propose an architecture for the design of Bandwidth Brokers that combines an adaptive admission control algorithm for increased utilization of network resources and a mechanism for reducing the complexity overhead that intends to be both simple and effective. Specifically, we present a novel architecture for the admission control module that aims at achieving a satisfactory balance between maximizing the resource utilization for the network provider and minimizing the overhead of the module. We complement our theoretical discussion with extensive experimental simulations for the proposed Bandwidth Broker components and analysis of the results. The simulations study the possible configurations of the proposed algorithm and also compare it with alternative admission control policies. Copyright © 2007 John Wiley & Sons, Ltd.
On fusion of PCA and a physical model‐based predictive control strategy for efficient load‐cycling operation of a thermal power plant
Authors: Prasad Girijesh 
Published: February 2007

AbstractControlling a thermal power plant optimally during load‐cycling operation is a very challenging control problem. The control complexity is enhanced further by the possibility of simultaneous occurrence of sensor malfunctions and a plethora of system disturbances. This paper proposes and evaluates the effectiveness of a sensor validation and reconstruction approach using principal component analysis (PCA) in conjunction with a physical plant model. For optimal control under severe operating conditions in the presence of possible sensor malfunctions, a predictive control strategy is devised by appropriate fusion of the PCA‐based sensor validation and reconstruction approach and a constrained model predictive control (MPC) technique. As a case study, the control strategy is applied for thermal power plant control in the presence of a single sensor malfunction. In particular, it is applied to investigate the effectiveness and relative advantage of applying rate constraints on main steam temperature and heat‐exchanger tube‐wall temperature, so that faster load cycling operation is achieved without causing excessive thermal stresses in heat‐exchanger tubes. In order to account for unstable and non‐minimum phase boiler–turbine dynamics, the MPC technique applied is an infinite horizon non‐linear physical model‐based state‐space MPC strategy, which guarantees asymptotic stability and feasibility in the presence of output and state constraints. Copyright © 2007 John Wiley & Sons, Ltd.
Radiation‐induced graft modification of knitted poly(ethylene terephthalate) fabric for collagen immobilization
Authors: Gupta Bhuvanesh , Revagade Nilesh , Atthoff Björn , Hilborn Jöns 
Published: February 2007

AbstractRadiation‐induced graft co‐polymerization of methacrylic acid and N‐vinyl‐2‐pyrrolidone mixture from poly(ethylene terephthalate) knitted fabrics were conducted using a preirradiation method. The influence of the graft conditions, such as irradiation dose, reaction time, monomer concentration and temperature on the degree of grafting was determined. It was found that there is a limiting irradiation dose of 40 kGy above which the degree of grafting does not increase. An increase in the monomer concentration from 20 to 40% and an increase in temperature from 60 to 80°C gave a higher initial rate of grafting as well as higher equilibrium graft levels. The characterization of the fabric was carried out by attenuated total reflectance infrared spectroscopy (ATR‐IR), X‐ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The grafted fabric surface, carrying negatively charged carboxylate ions, was shown to attract collagen, being positively charged to provide bioreceptive surfaces. Copyright © 2007 John Wiley & Sons, Ltd.
Effect of comonomer on thermal/mechanical and shape memory property of L‐lactide‐based shape‐memory copolymers
Authors: Min Changchun , Cui Wenjin , Bei Jianzhong , Wang Shenguo 
Published: February 2007

AbstractIn this study, three kinds of L‐lactide‐based copolymers, poly(lactide‐co‐glycolide) (PLGA), poly(lactide‐co‐p‐dioxanone) (PLDON) and poly(lactide‐co‐caprolactone) (PLC), were synthesized by the copolymerization of L‐lactide (L) with glycolide (G), or p‐dioxanone (DON) or ε‐caprolactone (CL), respectively. The copolymers were easily soluble in common organic solvents. The compositions of the copolymers were determined by 1H‐NMR. Thermal/mechanical and shape‐memory properties of the copolymers with different comonomers were compared. Moreover, the effect of the chain flexibility of the comonomers on thermal/mechanical and shape‐memory properties of the copolymers were investigated. The copolymers with appropriate lactyl content showed good shape‐memory properties where both the shape fixity rate (Rf)and the shape recovery rate (Rr) could exceed 95%. It was found that the comonomers with different flexible molecular chain have different effects on their thermal/mechanical and shape‐memory properties. Among them, PLGA has the highest mechanical strength and recovery rate while PLC copolymer has high recovery rate when the lactyl content exceeded 85% and the lowest transition temperature (Ttrans). Copyright © 2007 John Wiley & Sons, Ltd.
Carboxymethyl poly(L‐histidine) as a new pH‐sensitive polypeptide at endosomal/lysosomal pH
Authors: Asayama Shoichiro , Kato Hiroyuki , Kawakami Hiroyoshi , Nagaoka Shoji 
Published: February 2007

AbstractA carboxymethyl poly(L‐histidine) has been synthesized as a new pH‐sensitive polypeptide at endosomal/lysosomal pH. Because of its poor water solubility at physiological pH, an application of poly(L‐histidine) with a pKa around 6.0 has been limited in spite of the native possession of the pH‐dependent property change at endosomal pH. Although the unmodified poly(L‐histidine) suddenly precipitates out of the aqueous medium above pH 6.0 as the result of the deprotonation of the imidazole groups, the water solubility of the resulting carboxymethyl poly(L‐histidine) has been improved at physiological pH. A solution turbidity measurement proved that no significant effect on a rapid aggregate formation or phase separation of serum proteins is induced by carboxymethyl poly(L‐histidine). Hemolysis assay showed that the carboxymethyl poly(L‐histidine) enhances membrane disruptive ability at endosomal/lysosomal pH. The cellular uptake of luciferase in the presence of the carboxymethyl poly(L‐histidine) increases intracellular luciferase activity, which suggests that the carboxymethyl poly(L‐histidine) makes the luciferase escape from lysosomal degradation. The carboxymethyl poly(L‐histidine) would be the fundamental compound for designing various drug carriers with the pH sensitivity at endosomal/lysosomal pH. Copyright © 2007 John Wiley & Sons, Ltd.
The effects of the potential and polarization time on the performance of ionic polymer metal composite actuators: a control of forward and reverse displacements
Authors: Shoji Eiichi , Hirayama Daisuke 
Published: February 2007

AbstractThis paper focuses on the dependence of various waveforms of the potential on the displacement of Nafion‐platinum based IPMC actuators at 40 and 90% relative humidity (RH). In comparison with simpler square waveforms, a waveform that is being composed by inclusion of a rest potential of 0 V has given a longer displacement. This benefit was effective at lower humidity conditions. By a polarization, the actuators show three major displacement processes of maximum forward displacement, steady forward displacement, and maximum reverse displacement. Here, the dependence of the potential and polarization time on these displacements has been carefully examined. An increase in the forward displacement by the potential does not strongly affect a slower reverse relaxation. To give a suitable relaxation period before a polarity switching of the potential seems effective to release the internal stress of the actuator. An elevated drive potential has decreased in the bending speed apparently. Finally, it has been noted that the ‘recovery’ of the maximum displacement is possible if a suitable waveform is applied to the actuator. This recovery effect is more remarkable at higher dive potential. Copyright © 2007 John Wiley & Sons, Ltd.
Control of orientation for carbazole group in comb copolymers arranged by method of organized molecular films
Authors: Hoshizawa Hiroko , Masuya Ryosuke , Masuko Toru , Fujimori Atsuhiro 
Published: February 2007

AbstractWe investigated the molecular orientation of organized molecular films with regard to solid‐state structures for newly synthesized comb copolymers with N‐vinylcarbazole (NVCz) by in‐plane and out‐of plane X‐ray diffraction (XRD), differential scanning calorimetry (DSC), and atomic force microscopy (AFM). In the bulk state, hydrogenated and fluorinated comb copolymers form side‐chain crystals for a two‐dimensional lattice spacing of 4.2 and 5.0 Å, respectively. The findings suggest that the carbazole rings in the main‐chain are arranged in opposition to each other. From the results of the DSC measurement, sharp‐shaped melting peaks appear on the relatively lower temperature side of the thermograms. This result supports the formation of side‐chain crystals in the synthesized comb copolymers. These monolayers of the copolymers on the water surface were extremely condensed, except for the fluorocarbon:NVCz = 1:1 copolymer. From the in‐plane XRD measurement of multilayers on solids, the changes in the two‐dimensional lattice structure of fluorinated comb copolymer films containing NVCz units, as opposed to their bulk state, were confirmed. It seems that these structural changes are caused by the stronger π–π interaction between the carbazole rings rather than the van der Waals interaction between fluorocarbons. Copyright © 2007 John Wiley & Sons, Ltd.
Viscoelastic and damping characteristics of poly(n‐butyl acrylate)‐poly(n‐butyl methacrylate) semi‐IPN latex films
Authors: Suresh K. I. , Vishwanatham S. , Bartsch E. 
Published: February 2007

AbstractThis article reports the synthesis, characterization, and damping characteristics of semi‐interpenetrating (semi‐IPN) latex systems composed of poly n‐butyl acrylate (PBA) core and poly n‐butyl methacrylate (PBMA) shell. The IPN's were prepared by seeded emulsion polymerization using crosslinked PBA seeds with varying crosslinker (m‐diisopropenyl benzene) concentration. The polymer weight ratio in the first and second stage polymerization is maintained at 1:1 in all the cases. The particle size determined by dynamic light scattering shows a decrease in the shell thickness with increasing crosslinker concentration of the seed. The mechanical properties, like Shore A hardness of the films, increased from 18 to 65 when the crosslinker concentration is increased from 0 to 4.8 mol%. The dynamic mechanical studies show that the modulus value of the IPN's is below that of non‐crosslinked films, and the value depends upon the crosslink density of the seed. Mechanical models, such as the Kerner's model and the Takayanagi's model, were used to explain the variation in the dynamic mechanical properties with the degree of seed crosslinking. The study indicates lower bound (rubbery) behavior for the films with lightly crosslinked cores. The study also shows that, at lower crosslinker concentration enhanced phase separation and better damping properties are achieved but at higher cross linker concentration (>2 mol%) greater interpenetration of the shell monomer to the cores takes place and tough films, with reduced damping properties are formed. Copyright © 2007 John Wiley & Sons, Ltd.
Alumina supported synthesis of Cassia marginata gum‐g‐poly(acrylonitrile) under microwave irradiation
Authors: Singh V. , Kumari P. L. , Tiwari A. , Sharma A. K. 
Published: February 2007

AbstractIn view of the known advantages of the microwave promoted reactions done in dry medium, the seed gum sourced from Cassia marginata has been graft copolymerized with acrylonitrile in dry medium at neutral alumina support under microwave irradiation. Grafting conditions were optimized and the representative graft copolymer was characterized by Fourier transform‐infrared, Thermo gravimetric analysis, Scanning electron microscopy, and X‐Ray Diffraction (XRD) measurement, taking Cassia marginata gum (CM) as reference. Much higher % grafting and % efficiency could be obtained in the microwave promoted alumina supported grafting as compared to grafting done in aqueous medium (microwave promoted and conventional). Properties of the microwave synthesized Cassia marginata gum‐graft‐poly(acrylonitrile) (CM‐g‐PAN) were studied and compared with the parent seed gum. © 2007 John Wiley & Sons, Ltd.
Flightless I deficiency enhances wound repair by increasing cell migration and proliferation
Authors: Cowin AJ , Adams DH , Strudwick XL , Chan H , Hooper JA , Sander GR , Rayner TE , Matthaei KI , Powell BC , Campbell HD 
Published: February 2007

AbstractWound healing disorders are a therapeutic problem of increasing clinical importance involving substantial morbidity, mortality, and rising health costs. Our studies investigating flightless I (FliI), a highly conserved actin‐remodelling protein, now reveal that FliI is an important regulator of wound repair whose manipulation may lead to enhanced wound outcomes. We demonstrate that FliI‐deficient + /− mice are characterized by improved wound healing with increased epithelial migration and enhanced wound contraction. In contrast, FliI‐overexpressing mice have significantly impaired wound healing with larger less contracted wounds and reduced cellular proliferation. We show that FliI is secreted in response to wounding and that topical application of antibodies raised against the leucine‐rich repeat domain of the FliI protein (FliL) significantly improves wound repair. These studies reveal that FliI affects wound repair via mechanisms involving cell migration and proliferation and that FliI might represent an effective novel therapeutic factor to improve conditions in which wound healing is impaired. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Use of benzodiazepines and benzodiazepine receptor agonists during pregnancy: maternal characteristics
Authors: Wikner Birgitta Norstedt , Stiller Carl‐Olav , Källén Bengt , Asker Charlotte 
Published: February 2007

AbstractBackgroundUse of benzodiazepine (BZD) drugs or hypnotic benzodiazepine receptor agonists (HBRAs) during pregnancy may represent a hazard for the foetus. In order to analyse this in an adequate way, knowledge of maternal characteristics as putative confounders is needed.MethodsIn the Swedish Medical Birth Register, 2149 pregnant women using BZDs or HBRAs were identified, 1944 of them in early pregnancy. These women were compared with other women (n = 859 455) giving births during the same period (1 July 1995–31 December 2004). The following maternal characteristics were studied: age, parity, smoking habits, education, previous miscarriages, years of involuntary childlessness as an estimate of subfertility, concomitant drug use and some pregnancy complications.ResultsUse and/or reporting of BZDs or HBRAs increased with maternal age. It was higher at first and 4+ parity and increased markedly with maternal smoking. Women with low education reported a higher use than women with high education. Previous miscarriage or subfertility had little impact on the use of these drugs. Preterm birth and caesarean section (also at term birth) were more common than expected. In women using BZDs or HBRAs, other types of psychoactive drugs were used in excess.ConclusionsWomen using BZDs or HBRAs differ in many aspects from women not using those drugs. These differences may act as confounders in the analysis of pregnancy outcome. Copyright © 2007 John Wiley & Sons, Ltd.
Geschwindigkeitsrekord auf der Datenautobahn: Hochratige optische Datenübertragung in Glasfasernetzen
Authors: Schmidt‐Langhorst Carsten , Schubert Colja , Ludwig Reinhold , Weber Hans‐Georg 
Published: February 2007

AbstractDie optische Datenübertragung in Glasfasernetzen bildet das Rückgrat der weltweiten Kommunikation. Auch wenn zur Kommunikation zunehmend breitbandige mobile Endgeräte eingesetzt werden, benötigt das weltweite Kommunikationsnetz leistungsfähige faseroptische Kernnetze. Die Übertragungssysteme haben zurzeit je nach Übertragungslänge eine maximale Kapazität von etwa 1 bis 5 Terabit/s und verwenden eine Datenrate von maximal 40 Gigabit/s in einem einzelnen Wellenlängenkanal. Im Labor konnten in einem Kanal schon 2,56 Terabit/s übertragen werden. Das ist der aktuelle Geschwindigkeitsweltrekord.
Streitbare Entdeckungen im Reich der Planeten
Authors: Heering Peter 
Published: February 2007

AbstractDie Entdeckung eines neuen Planeten galt 200 Jahre lang als Sensation, die in Windeseile um die Welt ging. Einige der Neuankömmlinge wurden indes bald wieder ins Reich der Planetoiden oder Asteroiden verwiesen. Nun ereilte 76 Jahre nach seiner Entdeckung auch den Planeten Pluto dieses Schicksal.
Magnetische Kühlung für Gase
Authors: Koch Tobias , Pfau Tilman 
Published: February 2007

AbstractMit einer bereits 1950 vom französischen Nobelpreisträger Alfred Kastler vorgeschlagenen Methode ist es einer Forschergruppe am 5. Physikalischen Institut der Universität Stuttgart gelungen, eine Wolke ultrakalter Chromatome nahezu verlustfrei zu kühlen.
Enhanced Crystallinity of PTFE by Ion Irradiation in a Dense Plasma Focus
Authors: Sadiq Mehboob , Ahmad Sarfraz , Shafiq Muhammad , Zakaullah Muhammad 
Published: February 2007

AbstractNitrogen‐ion beam pulses emitted from a low‐energy (1.45 kJ) Mather‐type plasma focus device are used for the surface modification of PTFE polymer specimens. The specimens, placed at a fixed position, are implanted using different number of pulses. Raman spectroscopy and XRD are employed to probe the structural changes incurred during the ion implantation. Both techniques indicate that the crystalline order in the specimens increases with increasing the irradiation dose. The crystallinity degree of the irradiated specimens, as measured from the XRD data, is found to enhance monotonically from 40% to about 55%. Possible crystallinity enhancement mechanism of irradiated PTFE specimens via chain scission is discussed.magnified image
Study of the Si Chemical Bonding and the Semiconductive Behavior of SiCN Coatings and their Correlation with Anti‐Corrosion Properties
Authors: Loir Anne‐Sophie , Pech David , Steyer Philippe , Gachon Yves , Héau Christophe , Sánchez‐López Juan Carlos 
Published: February 2007

AbstractAmorphous hydrogenated SiCN coatings have been deposited by a PACVD process on M2 steel and silicon substrates. The nitrogen content within the coatings was varied by changing the synthesis conditions. The chemical composition and nature of bonding have been studied by XPS and by X‐ray‐induced AES. The electrochemical and the semi‐conductive properties were evaluated by polarization curves and by using the Mott‐Schottky experiments, respectively. When increasing the N/Si ratio, we observed an increase of Si atoms inside the film structure, which were directly bonded to nitrogen. This gradual incorporation of N modified the electrochemical behavior of the films displaying a variation of the density of charge carriers and the semiconductive behavior (p‐ to n‐type). The modified Auger parameter of silicon was used to determine the nature of the silicon chemical bonding inside the [SiCN]‐based coatings and to predict their corrosion behavior.magnified image
Plasma Polymerization Behavior of Fluorocarbon Monomers in Low‐Pressure AF and RF Discharges
Authors: Gilliam Mary A. , Yu Qingsong , Yasuda Hirotsugu 
Published: February 2007

AbstractThe plasma polymerization behavior of fluorocarbon monomers was investigated using C3F6, C3F6O, C4F10 and C2F4H2, which were compared to hydrocarbons such as methane and butane. The plots of the normalized thickness growth rates of plasma polymers, GR/FM, versus the energy input composite parameters, W/FM, revealed the energy‐deficient and monomer‐deficient domains for each monomer, along with the critical energy input, (W/FM)c, representing the transition between the two domains. The luminous gas phase in fluorocarbon discharges does not contain much polymer‐forming species and thus, the monomer‐deficient domain shifted to a much lower W/FM and GR/FM values than in the case of hydrocarbon systems. For hydrocarbon systems, deposition rates were greater in RF than in AF discharges, which is opposite to the situation observed for the fluorocarbon systems. These differences were attributed to the locations of the dissociation glows and to the nature of the luminous gas phase in respect to polymer‐forming species.magnified image
Synthesis of Metal Oxide Thin Films by Reactive Magnetron Sputtering in Ar/O2 Mixtures: An Experimental Study of the Chemical Mechanisms
Authors: Snyders Rony , Dauchot Jean‐Pierre , Hecq Michel 
Published: February 2007

AbstractOne of the major limitations of reactive magnetron sputtering (RMS) is the low deposition rate when the target is poisoned. With the goal of reducing this phenomenon, we studied the chemical mechanisms involved during conventional and ionized reactive magnetron sputtering (iRMS) of metals (Sn, Ti, Ag) in Ar/O2 mixtures. Target surface, plasma and film compositions were characterized by target voltage, MS and XPS measurements, respectively. Comparing films and plasma compositions, we demonstrated that oxide film formation proceeds by condensation of sputtered material and reaction between the growing film and the reactive species, especially O. Using iRMS, we promoted the latter process: for example, we prepared fully oxidized Sn films using low O2 flows which limits target poisoning and, in turn, increases the deposition rate (6 times).magnified image