bluuebunny/crossref_metadata_2025 huggingface dataset:
Rapid Identification of Muscle Activation Profiles via Optimization and Smooth Profile Patches
Authors: Strobach Daniel , Kecskemé Andrés
Published: December 2005

The identification of muscle activation profiles of the musculoskeletal system is an important ans still open problem in biomechanics. Current methodology consists in finding the amplitude and the time history of the activation functions through optimization techniques. In this setting, function parameterizations such as discretization through sampling values, rectangular and ramp functions, as well as splines have been investigated. However, typical optimization runs display prohibitively long computation times, which make them unsuitable for on‐line applications, such as required for example for patient‐specific therapy. the present paper proposes a new method for parameterizing muscle activation profiles employing smooth (C∞) base functions. The ides is that, for the target approximation of dynamical motions, the detailed geometry of the activation profiles not significant, while its smoothness facilitates the search within the optimization procedure. The results show that, by applying these methods, the required CPU time can be reduced by factors up to 8. We analyze the method for a flexion/extension two joint subsystem of hip and knee, comprising two pairs of antagonistic muscles, showing the sensitivity to sampling time and initial values. From these studies it becomes obvious that determination of muscle activation through optimization can be very sensitive to carefully chosen parameterizations. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Identification of plastic material parameters with error estimation
Authors: Unger Jaan , Stiemer Marcus , Svendsen Bob , Blum Heribert
Published: December 2005

In recent years, inverse analysis has become a common approach to typical engineering problems such as model identification. In this contribution, the inverse problem is discussed in light of taking experimental uncertainties into account. This involves in particular the propagation of experimental errors and the analysis of the sensitivity of the model response to variations in the model parameters to be determined. The method is applied to an elasto‐viscoplastic material model which is used in the context of electromagnetic high‐speed forming. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Experimentelle Methode zur Bestimmung der Kräfte an Tropfen auf Oberflächen mit einem Gradienten der Benetzbarkeit
Authors: Zielke Paul Ch. , Szymczyk Janusz A.
Published: December 2005

Von besonderem Interesse bei der Untersuchung der Bewegung von Tropfen auf Oberflächen mit einem Gradienten der Benetzbarkeit sind die am Tropfen wirkenden Kräfte. Es wird eine Methode vorgestellt, mit der unter Ausnutzung der Zentrifugalkraft diese Kräfte bestimmt werden können. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical Investigation of Wall Catalysis in High‐Enthalpy Flows
Authors: Reinartz Birgit U. , Ballmann Josef
Published: December 2005

A Navier‐Stokes solver is applied to assess the effect of wall catalysis on the surface heat flux of hypersonic vehicles. The different catalytic boundary conditions are shortly discussed and results for a type IV interaction on a cylinder are presented and compared to experimental measurements. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Energetische Betrachtungen zum Rayleigh‐Stokes Problem
Authors: Bühler Karl , Zierep Jürgen
Published: December 2005

Energetische Aspekte gewinnen bei nachhaltig optimierten Systemen zunehmend an Bedeutung. Klassische Lösungen der Strömungsmechanik sind für viele technische Anwendungen von enormerWichtigkeit. In dieser Arbeit präsentieren wir energetische Analysen zu den unterschiedlichen Rayleigh‐Stokes Problemen wie der plötzlich in Gang gesetzten oder gestoppten Platte sowie der periodisch oszillierenden Platte. Die in [1] beschriebenen klassischen Rayleigh‐Stokes Probleme sind in vielfältigerWeise für verallgemeinerte Rand‐ und Anfangsbedingungen untersucht worden. Beispiele hierzu sind in [2, 3] dargestellt. Theoretische Grundlagen zu den folgenden energetischen Betrachtungen sind in [4, 5] enthalten. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Drag Reduction in Wall Bounded Flows: The Effect of Polymers on the Dynamics of Turbulence
Authors: Frohnapfel Bettina , Jovanović Jovan , Pashtrapanska Mira , Durst Franz
Published: December 2005

Experiments in a refractive index matched pipe flow facility were conducted using state‐of‐the‐art laser‐Doppler anemometry to study turbulent drag reduction by dilute addition of high polymers. The results were analyzed employing the invariant theory of turbulence. It was thus possible to confirm the major conclusion of preceding theoretical work, namely that the mechanism of drag reduction by long‐chain polymers is associated with an increase in anisotropy of turbulence at the wall. Furthermore, theoretical considerations based on the elastic behavior of a polymer and spatial intermittency of turbulence at small scales enabled quantitative estimates to be made for the relaxation time of a polymer and its concentration that ensures maximum drag reduction. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Effect of the Backward‐Facing Step Height on Flow in a Channel with Rectangular Cross Section
Authors: Jonáš Pavel , Mazur Oton , Uruba Václav
Published: December 2005

The investigation of a channel flow with a backward‐facing step on one wall is described. The height of the incoming channel H is adjustable as to allow alter the ratio of step height h over H; h/H = 1 : 10, 1 : 4, 1.02 : 1(h + H = 0.275m). Mutual correlations between the extremes of static pressure distributions, limits of the separation zone and of the corner vortex structures and Reynolds number are discussed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Reorientation of Cryogenic Fluids Upon Step Reduction of Gravity
Authors: Stief Malte , Gerstmann Jens , Dreyer Michael E.
Published: December 2005

Experiments to observe the surface oscillation of cryogenic liquids have been performed with liquid nitrogen inside a 50 mm diameter right circular cylinder. The surface oscillation is driven by the capillary force that becomes dominant after a sudden reduction of the gravity acceleration acting on the liquid. The experiments show differences from the speculated behavior and enables one to observe new features. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerische Untersuchung der Strömung in Gleitlagern
Authors: Stücke Peter , Scurtu Nicoleta , Egbers Christoph
Published: December 2005

Es soll die Strömung im Gleitlager in Abhängigkeit von Form‐ und Betriebsparametern untersucht werden. Da eine fertige problembezogene Lösung noch nicht vorliegt, wird ein Ansatz gewählt, der von vorliegenden Untersuchungen ausgeht und auf einer Kombination von experimentellen und numerischen Methoden basiert. Dieses Vorgehen ist allgemein anerkannt und hat sich in der Vergangenheit bewährt. Insgesamt sollen so Strömungsphänomene identifiziert werden, die mit dem Auftreten der Kavitation, wie sie am Gleitlagerprüfstand provoziert werden kann, korrelieren. Daraus sollen Empfehlungen abgeleitet werden, die zu einer sicheren Konstruktion von Gleitlagern f ühren. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On a Synthetic Jet Flow
Authors: Uruba Vaclav
Published: December 2005

Velocity vector field of a synthetic jet has been investigated experimentally. The synthetic jet is generated by an electrodynamical system designed for control of a free shear layer. To catch unsteady periodical structures the phase average method is applied to time series of instantaneous velocities. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
DNS and Lie group analysis of turbulent boundarly layer flow
Authors: Khujadze G. , Oberlack M.
Published: December 2005

Lie group approach is used to derive new scaling laws for zero‐pressure gradient turbulent boundary layer flow. A direct numerical simulation of the flow at Reynolds number Reθ = 2240 was performed for the verify theoretical results. Navier‐Stokes equations were numerically solved using spectral method with up to 160 million grid points. The numerical simulation shows validity of the theoretical results. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Turbulent compressible fluid flow computation in a male rotor‐housinggap of screw compressors
Authors: Vimmr Jan
Published: December 2005

This contribution is devoted to a turbulent compressible fluid flow computation through a 2‐D model of the male rotor‐housing gap in screw compressors. For the numerical solution of the nonlinear conservative system of the Favre‐averaged Navier‐Stokes equations the cell‐centred finite volume formulation of the explicit two‐step TVD MacCormack scheme proposed by Causon on a structured quadrilateral grid is used. The turbulent viscosity is calculated by using the algebraic Baldwin‐Lomax turbulence model which is implemented into the own developed numerical code. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The near wall region of turbulent natural convection flows: asymptotic considerations
Authors: Hölling Marc , Herwig Heinz
Published: December 2005

Turbulent natural convection along vertical walls is analysed asymptotically, i.e. for the Rayleigh‐number Ra → ∞. As a result universal temperature and velocity profiles are deduced that are valid for high Rayleigh numbers and can be used as wall functions in CFD‐codes. Constants in this asymptotic profiles are obtained by analysing high quality experimental and DNS data. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical Investigations of Process Heterogeneities during High Hydrostatic Pressure Treatment with Turbulent Inflow Conditions
Authors: Kitsubun Panit , Hartmann Christoph , Delgado Antonio
Published: December 2005

During the compression phase of high pressure treatment of aqueous food, the temperature locally increases approx. 2‐3 K per 100 MPa in the isentropic case as a result of the external work done by the volume change of the fluid. It could be concluded in the authors' previous contributions that heat transfer induces undesired process non‐uniformities, and therefore, significantly influences the product quality. However, the turbulent inflow conditions existing in larger autoclaves are expected to change homogeneity of the thermofluiddynamical fluid. In this contribution, the presence of the turbulence generated during the compression phase of the High ‐Pressure‐treatment and its influence on process non‐uniformities throughout the high pressure processing are investigated numerically. For the numerical simulations, a three‐dimensional model of a cylindrical autoclave with a net volume of 3.3 Litre is created. To investigate the influence of the turbulence on product quality, a model of the inactivation of the enzyme Bacillus Subtilis α‐Amylase is employed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of Varying Pressure on Natural Convection and Radiation Heat Transfer in an Enclosure
Authors: Langebach Jan , Senin Stephan , Karcher Christian
Published: December 2005

An experimental study on coupled heat transfer of natural convection and directed radiation is presented. These effects appear in automotive headlamps, for instance. To separate them, the pressure inside the enclosure is varied. As the Grashof number scales like Gr ∼ p2, upon decreasing pressure, convection is strongly suppressed while radiation remains unchanged. The experimental setup consists of a semi‐transparent lens and an automotive reflector arranged in a closed tube (300mm length, 180mm diameter). Almost all radiation from the lamp is directed from the reflector to the lens. There it is partly absorbed causing unfavourable hot spots. The location of these spots strongly depends on the interaction of convection and radiation. To improve the understanding of these effects, the location and the temperature of the spots were measured while varying the pressure from 102 to 105 Pa and the electrical power of the lamp from 10W to 15W, respectively. Besides, two different distances between the reflector and the lens were analysed. It was found that upon decreasing pressure, the hot spot temperature rises and the location moves closer to the optical axis of the reflector. Moreover, the wall temperature above the reflector decreases. The results will be compared with predictions of numerical simulations. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Anwendung der Ultraschall Doppler Messtechnik zur Analyse der konvektiven Transportvorgänge während des Gärungsprozesses in Gärtanks
Authors: Meironke H. , Szymczyk J. A.
Published: December 2005

Das Vergären und Lagern von Bier wird heute fast ausschließlich in zylindrokonischen Gärtanks im Single‐Tank Verfahren durchgeführt. Die bisherige angewandte Technik und Verfahrensweise begründet sich aus den langjährigen Erfahrungen mit diesen Gärtanks. Dabei sind die strömungsmechanischen Vorgänge innerhalb dieser Tanks, bedingt durch die komplexen Zusammenhänge der sich überlagernden physikalischen und biochemischen Prozesse sowie durch die in der Vergangenheit fehlenden Messtechniken, noch nicht umfassend experimentell untersucht worden. Die vorliegende Arbeit stellt ein Strömungsdiagnosesystem vor, welches speziell für die Konvektion im Gärtank auf der Grundlage der Ultraschall Doppler Messtechnik entwickelt wurde. Mittels dieses Messsystems sind umfangreiche Messungen in einem 270 Liter Modelltank und in einem industriellen 30.000 Liter Gär‐ und Lagertank durchgeführt worden. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transport and Reaction Processes in Concrete at High Temperatures
Authors: Ostermann L. , Dinkler D.
Published: December 2005

Simulating processes in concrete at high temperatures requires coupled formulation of transport and reaction. Transport can be formulated using balance equations for mass and heat as well as constitutive equations. The equations have to be valid in the whole temperature range from 293 K up to 1000 K. Instantaneous thermodynamic equilibrium is assumed for the gas and liquid phase of water substance. Above the critical point of water, only its gas phase exist. This requires a combined mass balance, which contains vapour balance as well as the mass balance of liquid water. Rapid evaporation of water and degradation of cement minerals leads to an enormous pressure increase in the gas phase. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Experimental Analysis of Thermal Convection in a Small Gap
Authors: Rubes D. , Wozniak G. , Heiland H. G.
Published: December 2005

The rapid progress in fabrication and utilizing of microelectromechanical systems during the last decade has reinforced the need of a more detailed understanding of the fluid behavior in small volumes. Our investigation focuses on the fluid behavior in a small vertical gap when applying a temperature gradient and using a 30% and 60% glycerin/water solution. Liquid crystals are used to measure simultaneously velocity and temperature distributions. The technique is explained and selected results are presented. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stability of thermocapillary‐driven flow in rectangular cavities
Authors: Schimmel Frank , Albensoeder Stefan , Kuhlmann Hendrik
Published: December 2005

The flow in an infinitely extended cavity with rectangular cross section is considered. The upper boundary is a free surface where thermocapillary forces are driving a circulation within the cavity (Marangoni effect). If the driving force (temperature difference) exceeds a critical threshold, the two dimensional flow becomes unstable towards an infinitesimal three‐dimensional perturbation. The critical mode depends on the aspect ratio and may be steady or oscillatory. Results are presented for vanishing Prandtl number and varying aspect ratios of the cavity. These are compared to the classical lid‐driven cavity problem and the mechanism leading to instability is discussed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Measuring surface temperatures using Thermochromic Liquid Crystals
Authors: Senin Stepan , Langebach Jan , Karcher Christian
Published: December 2005

Thermochromic Liquid Crystals (TLCs) are used to measure the temperature distribution and to examine convective heat transfer on surfaces. This technique is specifically intended for investigating outer surface temperature fields and requires complex image data decomposition with colour analysis. This study presents a new method of using TLCs for the temperature measurement inside experimental models. The change of optical behaviour of TLCs is measured with a luminance camera. Therefore, it is possible to measure the complete distribution of the surface temperature, i.e. both inside and outside of the model. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Wärmeübergang von Kohlendioxid im thermodynamisch kritischen Gebiet
Authors: Spindler Klaus
Published: December 2005

Seit einiger Zeit wird Kohlendioxid als Arbeitsmittel in Kältemaschinen und Wärmepumpen erprobt. Vor dem Hintergrund es geplanten Verbotes der sogenannten F‐Gase mit hohem Treibhauspotenzial wird die Anwendung forciert. Die thermophysikalischen Eigenschaften sind sehr gut untersucht. Bedingt durch die niedrige kritische Temperatur von ca. 31°C ergeben sich auch Zustandsänderungen im kritischen oder überkritischen Gebiet. Die Stoffdaten weisen starke Änderungen im kritischen Gebiet auf. Gerade in diesem Temperaturbereich können sich großeWärmeübergangskoeffizienten einstellen. Es werden Korrelationen zum Wärmeübergang bei einphasiger Konvektion im überkritischen Gebiet vorgestellt. Der Einfluss der Stoffdaten auf den Wärmeübergang im thermodynamisch kritischen Gebiet wird diskutiert. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The effect of CP96,345 on the expression of tachykinins and neurokinin receptors in acute pancreatitis
Authors: Lau Hon Yen , Bhatia Madhav
Published: December 2005

Acute pancreatitis (AP) is a life‐threatening condition that involves an acute inflammatory process in the pancreas. The involvement of tachykinins and neurokinin receptors in acute pancreatitis has been described only recently, despite their long‐established role in inflammatory conditions. Among these, substance P (SP) is believed to play a central role in exacerbating the inflammatory process by acting through neurokinin‐1 receptor (NK1R). Treatment with the NK1R antagonist, CP96,345, results in protection against caerulein‐induced acute pancreatitis in mice. However, the mechanism by which NK1R and SP worsen the condition is still unclear. In the present study, we have investigated the effect of NK1R blockage on the expression of preprotachykinin genes and neurokinin receptors in acute pancreatitis. In the pancreas, CP96,345 treatment resulted in suppression of the elevation of SP concentration, preprotachykinin‐A gene (PPT‐A) mRNA expression, and NK1R mRNA and protein expression. In the lungs, the antagonist was found to suppress the increase in SP concentration, PPT‐A mRNA expression and preprotachykinin‐C gene (PPT‐C) mRNA expression. However, the antagonist treatment further promoted the accumulation of pulmonary NK1R mRNA and protein expression. Neurokinin‐2 receptor (NK2R) mRNA expression was not detected in normal pancreas. However, up‐regulated expression of the mRNA for this receptor was observed during acute pancreatitis and treatment with CP96,345 further increased this expression. Pulmonary NK2R mRNA expression was found to be reduced during acute pancreatitis and CP96,345 treatment normalized this reduction. Neurokinin‐3 receptor (NK3R) mRNA expression was absent in both pancreas and lung. These data have provided valuable information regarding the regulation of tachykinins and neurokinin receptors during acute pancreatitis. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Two infants with life‐threatening diffuse neonatal hemangiomatosis treated with cyclophosphamide
Authors: Gottschling Sven , Schneider G. , Meyer S. , Reinhard H. , Dill‐Mueller D. , Graf N.
Published: December 2005

Diffuse neonatal hemangiomatosis (DNH) is a rare, frequently fatal disorder characterized by multiple cutaneous and visceral hemangiomas. Complications include high‐output cardiac failure, hemorrhage, hepatic failure, and consumption coagulopathy. We present two cases of neonates with DNH. We prescribed cyclophosphamide after failure of corticosteroids. Cyclophosphamide induced a fast regression of the lesions with no side effects in both infants. We were able to stop treatment after 3–4 courses of cyclophosphamide in both infants because of the excellent response. Cyclophosphamide seems to be a safe and effective treatment in patients suffering from life‐threatening DNH unresponsive to corticosteroids. Pediatr Blood Cancer 2006;46:239–242. © 2005 Wiley‐Liss, Inc.
Long‐term follow‐up of pediatric cancer survivors: Education, surveillance, and screening
Authors: Landier Wendy , Wallace W. Hamish B. , Hudson Melissa M.
Published: December 2005

Cancer and its treatment predispose childhood cancer survivors to chronic or late occurring health problems that may not become clinically significant until many years after therapy. Frequently, long‐term survivors of childhood cancer report late cancer‐related effects that diminish quality of life and increase the risk of early mortality. Risk‐based health care that involves a personalized plan for surveillance, screening, and prevention is recommended to reduce cancer‐related morbidity in childhood cancer survivors. To implement optimal risk‐based care, the survivor and health care provider must have accurate information about cancer diagnosis, treatment modalities, and potential cancer‐related health risks to guide screening and risk‐reducing interventions. However, previous studies evaluating health knowledge of childhood cancer survivors demonstrate noteworthy deficits and misperceptions about their cancer diagnosis, treatment, and cancer‐related health risks. In addition, because of the relative rarity of childhood cancer, many health care providers lack familiarity with cancer‐related health risks and risk‐reduction methods relevant for this population. To correct these deficits, the Scottish Intercollegiate Guidelines Network (SIGN) and the Children's Oncology Group (COG) developed clinical practice guidelines to foster appropriate risk‐based survivor care. Herein, we discuss the development, benefits, and limitations of the SIGN and COG guidelines and the foundation they provide for standardizing long‐term follow‐up care of the ever‐growing vulnerable population of childhood cancer survivors. Pediatr Blood Cancer 2006;46:149–158. © 2005 Wiley‐Liss, Inc.
Barriers to follow‐up care of survivors in the United States and the United Kingdom
Authors: Oeffinger Kevin C. , Wallace W. Hamish B.
Published: December 2005

Survivors of pediatric cancer face an increased risk of morbidity, mortality, and diminished quality of life associated with their previous cancer therapy. Because these risks are often modifiable, periodic lifetime medical follow‐up is recommended for all survivors. This article assesses the current status of follow‐up care in the United States and the United Kingdom. Potential barriers in both cultures and health care environments are described. A better understanding of these barriers has led to the development and testing of interventions intended to optimize the health care of survivors. Pediatr Blood Cancer 2006;46:135–142. © 2005 Wiley‐Liss, Inc.
CuIn1−xGaxSe2‐based thin‐film solar cells by the selenization of sequentially evaporated metallic layers
Authors: Caballero R. , Guillén C. , Gutiérrez M. T. , Kaufmann C. A.
Published: December 2005

Polycrystalline CuIn1−xGaxSe2(CIGS) thin films were deposited by the non‐vacuum, near‐atmospheric‐pressure selenization of stacked metallic precursor layers. A study was carried out to investigate the influence of significant factors of the absorber on the solar cells performance. An efficiency enhancement was obtained for Cu/(In+Ga) atomic ratios between 0·93 and 0·95. The slope of the observed energy bandgap grading showed a strong influence on theVOCand the short circuit current densityJSC. An increase of the Ga content in the active region of the absorber was achieved by the introduction of a thin Ga layer on the Mo back contact. This led to an improvement of efficiency andVOC. Furthermore, an enhanced carrier collection was detected by quantum efficiency measurements when the absorber layer thickness was slightly decreased. Conversion efficiencies close to 10% have been obtained for these devices. Copyright © 2005 John Wiley & Sons, Ltd.
Back‐contact solar cells: a review
Authors: Kerschaver Emmanuel Van , Beaucarne Guy
Published: December 2005

Ever since the first publications by R.J. Schwartz in 1975, research into back‐contact cells as an alternative to cells with a front and rear contact has remained a research topic. In the last decade, interest in back‐contact cells has been growing and a gradual introduction to industrial applications is emerging. The goal of this review is to present a comprehensive summary of results obtained throughout the years. Back‐contact cells are divided into three main classes: back‐junction (BJ), emitter wrap‐through (EWT) and metallisation wrap‐through (MWT), each introduced as logical descendents from conventional solar cells. This deviation from the chronology of the developments is maintained during the discussion of technological results. In addition to progress on manufacturing these cells, aspects of cell modelling and module manufacturing are discussed and an outlook towards industrial implementation is presented. Copyright © 2005 John Wiley & Sons, Ltd.
Synthesis and properties of new fluorene‐based polyquinoxalines with an ether linkage in the main chain for light‐emitting diodes
Authors: Jung Sung‐Hyun , Kim Dong Young , Cho Hyun‐Nam , Suh Dong Hack
Published: December 2005

A new series of fluorene‐based polyquinoxalines with an ether linkage in the main chain were prepared by the polycondensation reaction between a tetraketone monomer and 3,3′,4,4′‐tetraaminodiphenyl ether. The polycondensation was usually carried out in m‐cresol. The resulting polymers (P1–P3) [P1 = poly(quinoxaline‐co‐9,9‐dihexyl‐2,7‐dimethyl‐9H‐fluorene) P2 = poly(quioxaline‐co‐9,9‐dihexyl‐9‐pentyl‐2,7‐di‐p‐tolyl‐9H‐fluorene) P3 = poly(quioxaline‐co‐9,9‐bis‐(4‐methoxy‐phenyl)‐2,7‐dimethyl‐9H‐fluorene)] showed good solubility in common organic solvents and high thermal stability with only a 5% weight loss up to 440 °C. P1 and P2 had very high glass‐transition temperatures of 212 and 223 °C, respectively, whereas P3 did not show any phase‐transition temperature in repeated scans up to 300 °C. All the polymers in photoluminescence showed blue emissions in the range of 432–465 nm, both in chloroform solutions and in thin films. Light‐emitting diode devices of the configuration indium tin oxide/poly(3,4‐ethylenedioxythiophene)/polymer:poly(N‐vinylcarbazole) blend (2:8)/LiF/Al were fabricated with P1 or P2 and emitted blue light with electroluminescence peak wavelengths of 434 and 448 nm, respectively. The maximum brightness and the external quantum efficiency of P1 were 0.56 μW/cm2 at 29 V and 0.056%, whereas P2 showed 0.50 μW/cm2 at 34 V and a relatively low value of 0.015%, respectively. Cyclic voltammetry studies revealed that these polymers possessed low‐lying ionization potential energy levels ranging from −5.49 to −5.86 eV and low‐lying electron affinity energy levels ranging from −2.65 to −2.88 eV. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1189–1198, 2006
Synthesis of poly(glycolic acid‐alt‐12‐aminododecanoic acid): The thermal polymerization kinetics of sodium N‐chloroacetyl‐12‐aminododecanoate
Authors: Botines E. , Franco L. , Ramis X. , Puiggalí J.
Published: December 2005

A new regular poly(ester amide) consisting of glycolic acid and 12‐aminododecanoic acid was synthesized by a thermal polycondensation method involving the formation of a metal halide salt. Polymerization could start in liquefied or solid phases, depending on the reaction temperature. The polymerization kinetics were investigated by isothermal and nonisothermal isoconversional methods. The reaction model was selected with both Coats–Redfern and isokinetic relationships. The activation energy was higher when the reaction took place mainly in the solid state. A compensation effect was found between the frequency factor and the activation energy. The thermal properties of the new polymer were studied as well as the isothermal crystallization from the melt state. Melt‐grown spherulites were studied by means of polarizing optical microscopy. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1199–1213, 2006
Characterization of elastomeric blends by atomic force microscopy
Authors: Achalla P. , McCormick J. , Hodge T. , Moreland C. , Esnault P. , Karim A. , Raghavan D.
Published: December 2005

The bulk mechanical properties of a blend of elastomers are found to depend on the micro and nano scale morphology of the phases of the materials in the blend. In this study, we examine the phase morphology of blends of incompatible elastomers using Atomic Force Microscopy (AFM). Specifically, nanoindentation and Tapping Mode AFM (TMAFM) imaging techniques are used as experimental tools for mapping the composition of unfilled elastomeric blends. Depending on the composition of the blend, either co‐continuous or discontinuous domain/matrix morphology is observed. To identify the different components in bromobutyl (BIIR)/natural rubber (NR) blends, nanoscale indentation measurements were made on the observed phase‐separated regions. Results from force mode AFM and mechanical measurements of bulk NR and BIIR are used to assist in the interpretation of the TMAFM results for the BIIR/NR blends. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 492–503, 2006
Conformational analysis of a potent SSTR3‐selective somatostatin analogue by NMR in water solution
Authors: Gairí Margarida , Saiz Pilar , Madurga Sergio , Roig Xavier , Erchegyi Judit , Koerber Steven C. , Claude Reubi Jean , Rivier Jean E. , Giralt Ernest
Published: December 2005

The three‐dimensional structure of a potent SSTR3‐selective analogue of somatostatin, cyclo(3–14)H‐Cys3‐Phe6‐Tyr7‐D‐Agl8(Nβ Me, 2‐naphthoyl)‐Lys9‐Thr10‐Phe11‐Cys14‐OH (des‐AA1, 2, 4, 5, 12, 13[Tyr7, D‐Agl8(Nβ Me, 2‐naphthoyl)]‐SRIF) (peptide 1) has been determined by 1H NMR in water and molecular dynamics (MD) simulations. The peptide exists in two conformational isomers differing mainly by the cis/trans isomerization of the side chain in residue 8. The structure of 1 is compared with the consensus structural motifs of other somatostatin analogues that bind predominantly to SSTR1, SSTR2/SSTR5 and SSTR4 receptors, and to the 3D structure of a non‐selective SRIF analogue, cyclo(3–14)H‐Cys3‐Phe6‐Tyr7‐D‐2Nal8‐Lys9‐Thr10‐Phe11‐Cys14‐OH (des‐AA1, 2, 4, 5, 12, 13[Tyr7, D‐2Nal8]‐SRIF) (peptide 2). The structural determinant factors that could explain selectivity of peptide 1 for SSTR3 receptors are discussed. Copyright © 2005 European Peptide Society and John Wiley & Sons, Ltd.
Interlinkages between internal and international migration and development in the Asian region
Authors: Skeldon Ronald
Published: December 2005

This paper examines the linkages between systems of internal migration and systems of international migration in the Asian region. In the context of changing global patterns of international migration on the one hand and urbanisation on the other, the paper briefly examines the evolution of two different traditions in migration research and policy: those concerned with international and those concerned with internal migration. Recognising that there is some blurring in any distinction between the two types of migration, the paper hypothesises that there are sufficient differences between the two systems to warrant separate identification. Although both can operate simultaneously, the paper goes on to posit two scenarios: that internal migration can lead to international migration; and that international migration can lead to internal migration. Evidence from various parts of South and East Asia is employed to examine the validity of these statements.

There is no single evolutionary path, and examples of both scenarios are found in Asia. The concentration of populations in urban areas can give rise to later international movements, but these international migrations themselves, by creating vacuums in areas of origin, can in turn generate internal migration. The history of colonial contact, too, can initiate international migration from particular areas, not necessarily just urban, which give rise to later internal movements. Internal and international migrations are integrated and it is necessary to consider them as a unified system rather than in isolation. The hierarchical movements link richer and poorer groups together and need to be understood in the context of the implementation of programmes of poverty alleviation. By attempting to link internal and international migration, this paper is a small step towards the creation of a more integrated framework for the study of population movement. Copyright © 2006 John Wiley & Sons, Ltd.
Balancing move and work: women's labour market exits and entries after family migration
Authors: Clark William A. V. , Huang Youqin
Published: December 2005

A substantial literature has examined the nature of mobility and migration and the link to workforce participation. In general that literature has documented the disadvantages to women who move or migrate with a partner during the mobility or migration process, but it suggests, especially for the US, that the disadvantage is temporarily limited. This study of the same process in the British labour market reaffirms a temporary deficit‐effect of two‐worker migration for women, but unlike the US labour market the process of re‐entry seems slower. There are modest monetary gains from mobility and migration, but these gains come for some families only when women enter the labour force after migration. The study reconfirms the importance of gender in the migration and mobility processes. Income, for women, recovers more slowly if a birth was registered in the migration interval. Copyright © 2006 John Wiley & Sons, Ltd.
International migration and the Rainbow Nation
Authors: Lucas David , Amoateng Acheampong Yaw , Kalule‐Sabiti Ishmael
Published: December 2005

Recent statistics suggest that emigration from South Africa is accelerating while documented immigration remains at low levels. Primary analysis of a 10% sample of the overseas‐born in South Africa from the 1996 census confirmed that Black immigrants to South Africa were shown to be predominantly unskilled males, who were no better qualified than the Black population in general. This contrasts with the apartheid era when South Africa built up a stock of overseas‐born skilled workers, mostly Whites, which was not replenished in the 1990s, partly because of restrictive immigration policies.

The UK is the major destination for South Africans but lacks detailed data on the characteristics of the immigrants. The second destination is Australia and New Zealand combined. Comparisons are made with published census data on the South Africa‐born in Australia and New Zealand. A majority of emigrants have post‐school qualifications and professional occupations, reflecting the selective immigration criteria of Australia and New Zealand. The analysis confirms the importance of human capital to potential emigrants even though they may wish to move for non‐economic reasons. It also supports the view that South Africa had moved from a brain exchange of Whites to a brain drain, thus compounding a national shortage of skilled workers. Copyright © 2006 John Wiley & Sons, Ltd.
Structural and electrical properties of Mo/n‐GaN Schottky diodes
Authors: Reddy V. Rajagopal , Ramesh C. K. , Choi Chel‐Jong
Published: December 2005

The electrical and structural properties of molybdenum (Mo) Schottky contact to n‐type GaN (4.07 × 1018 cm–3) have been investigated before and after annealing at 600 °C. Measurements show that the Schottky barrier height of the as‐deposited sample was 0.81 eV (I–V) and 1.02 eV (C–V), respectively. It is shown that when the sample is annealed at 400 °C the Schottky barrier height slightly decreases to 0.74 eV (I–V) and 0.92 eV (C–V), respectively. However, the barrier height degraded to 0.56 and 0.73 eV when the sample was annealed at 600 °C for 1 min in nitrogen ambient. Based on the Auger electron microscopy and X‐ray diffraction results, the formation of nitride phases at the Mo/n‐GaN interface could be the reason for degradation of Schottky barrier height upon annealing at 600 °C. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Superconductivity of InN
Authors: Inushima T. , Kato N. , Takenobu T. , Motokawa M.
Published: December 2005

The crystal structure of InN is wurtzite and its interplanar spacing of (10$ \bar 1 $1) is almost the same as that of tetragonal In(101). The crystallographic similarity produces many problems to solve about the electronic properties of semiconducting InN. Above all, there is a controversy over the possibility that In layers in InN that contains poly‐crystalline phase couple by tunneling and exhibit no substantial depression of their superconducting transition temperature from the bulk In value. Here we present a superconductor to insulator transition in highly disordered InN with grains having a (10$ \bar 1 $1) plane parallel to sapphire (0001). (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of semiconducting electrodes on properties of thin ferroelectric films
Authors: Glinchuk M. D. , Zaulychny B. Y. , Stephanovich V. A.
Published: December 2005

The influence of semiconducting electrodes on the properties of thin ferroelectric films is considered within the framework of the phenomenological Ginzburg–Landau theory. The contribution of the electric field produced by charges in the electrodes allowing for the screening length of the carriers is included in the functional of the free energy and so in the Euler–Lagrange equation for the film's polarization. Application of the variational method to the solution of this equation allows the transformation of the free energy functional into a conventional type of free energy with renormalized coefficients. The obtained dependence of the coefficients on the film thickness, temperature, electrodes, carrier screening length, and other parameters make it possible to calculate the dependence of the properties on these parameters by conventional minimization of the free energy. The semiconducting carrier screening length was shown to influence strongly the film's properties and critical parameters of the thickness‐induced phase transition. At some fixed temperature and thickness of the film electrode an induced phase transition from the ferroelectric to the paraelectric phase is shown to exist when the screening length of the carriers is larger than some critical value. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Temperature‐induced phase transition in simulated amorphous Al2O3
Authors: Van Hoang Vo , Hung Nguyen Hoang
Published: December 2005

Our previous simulation studies indicated the existence of pressure‐induced phase transition in liquid and amorphous Al2O3. In the current paper, we present the structural transformation of simulated amorphous Al2O3 from an octahedral to a tetrahedral network structure by heating from the high‐density amorphous (hda) model at constant pressure P = 0 GPa. The structure of the models was analyzed through the partial radial distribution functions (PRDFs), coordination number distributions, bond‐angle distributions and interatomic distances. Furthermore, significant differences in structural characteristics of low‐density amorphous (lda) models obtained by heating from the hda one and by cooling from the low‐density melt have been found and are presented. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
EPR of Nd3+ in congruent and nearly stoichiometric lithium niobate
Authors: Malovichko G. , Grachev V. , Okulov S. , Kokanyan E. , Henecker F. , Hofstaetter A. , Schirmer O.
Published: December 2005

Lithium niobate crystals doped with neodymium were studied with the help of electron paramagnetic resonance, EPR in the temperature range of 4.2–20 K. Tremendous narrowing of the EPR lines in nearly stoichiometric samples in comparison with congruent ones allowed us to distinguish four non‐equivalent centers, as well as line splitting caused by hyperfine interaction of neodymium electrons with nuclear spins of both magnetic isotopes 143Nd and 145Nd. It is shown that one of the centers has axial C3 symmetry, whereas all others have lowest C1 symmetry due to presence of intrinsic defects or/and charge compensation defects in the near neighborhood of Nd3+. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A study of phase transition in (NH4)3WO3F3 oxyfluoride by Raman scattering
Authors: Krylov A. S. , Gerasimova J. V. , Vtyurin A. N. , Fokina V. D. , Laptash N. M. , Voyt E. I.
Published: December 2005

Raman scattering spectra of perovskite‐like (NH4)3WO3F3 oxyfluoride are studied in the 70–3600 cm–1 frequency range and the 93–323 K temperature range including the transition point from orientationally disordered cubic phase into the lower symmetry one. Internal vibrations of ammonium ions and WO3F3 octahedra have been found to exhibit transition anomalies. Analysis of measurements suggests that the transition under study is due mainly to the ordering of octahedra. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
MADoSPRO: a new approach to molecular modelling studies on a series of DNA minor groove binders
Authors: Lauria Antonino , Diana Patrizia , Barraja Paola , Montalbano Alessandra , Cirrincione Girolamo , Dattolo Gaetano , Almerico Anna Maria
Published: December 2005

The aim of this work was devoted to develop a method to predict ΔG values for a series of minor groove binders. Starting from a matrix of docking dataset for 10 minor groove binders (known and not) to 20 DNA fragments, with various sequences, it was possible to analyze the interaction modes and to calculate the ΔG value for new derivatives through MADoSPRO procedure. The method allowed, through the QSPR analysis, to characterize the type of interactions in such complexes, that was demonstrated to be related to quantum chemical and electrostatic descriptors, in agreement with the information available in literature on the structural requirements of specific minor groove ligands.
Fault‐tolerant control of nonlinear processes: performance‐based reconfiguration and robustness
Authors: Mhaskar Prashant , Gani Adiwinata , Christofides Panagiotis D.
Published: December 2005

This work considers the problem of control system/actuator failures in nonlinear processes subject to input constraints and presents two approaches for fault‐tolerant control that focus on incorporating performance and robustness considerations, respectively. In both approaches, first a family of candidate control configurations, characterized by different manipulated inputs, is identified for the process under consideration. Performance considerations are first incorporated via the design of a Lyapunov‐based predictive controller that enforces closed‐loop stability from an explicitly characterized set of initial conditions (computed using an auxiliary Lyapunov‐based nonlinear controller). A hierarchical switching policy is derived, that uses stability considerations (evaluated via the presence of the state in the stability region of a control configuration) to ascertain the suitability of a candidate backup configuration and then performance considerations are again considered in choosing between the suitable backup configurations. Next, we consider the problem of implementing fault‐tolerant control to nonlinear processes subject to input constraints and uncertainty. To this end, we first design a robust hybrid predictive controller for each candidate control configuration that guarantees stability from an explicitly characterized set of initial conditions, subject to uncertainty and constraints. A switching policy is then derived to orchestrate the activation/deactivation of the constituent control configurations. Finally, simulation studies are presented to demonstrate the implementation and evaluate the effectiveness of the proposed fault‐tolerant control method. Copyright © 2005 John Wiley & Sons, Ltd.
Robust control for an uncertain chemostat model
Authors: Gouze Jean‐Luc , Robledo Gonzalo
Published: December 2005

In this paper we consider a control problem for an uncertain chemostat model with a general growth function and cell mortality. This uncertainty affects the model (growth function) as well as the outputs (measurements of substrate). Despite this lack of information, an upper bound and a lower bound for those uncertainties are assumed to be known a priori. We build a family of feedback control laws on the dilution rate, giving a guaranteed estimation on the unmeasured variable (biomass), and stabilizing the two variables in a rectangular set, around a reference value of the substrate. We give two realistic applications of this control law to a depollution process and to phytoplankton culture. Copyright © 2005 John Wiley & Sons, Ltd.
Linear PI control of batch exothermic reactors with temperature measurement
Authors: Alvarez‐Ramirez Jose , Alvarez Jesus
Published: December 2005

A wide variety of speciality materials and fine chemicals such as plastics, pharmaceutical and microelectronics components are produced in batch reactors. The nonlinear, transient and finite‐time features of the batch reactors give rise to complex process and control design problems. In particular, the safe operation of exothermic reactors depends on the adequate functioning of a temperature tracking controller, and to a good extent, the same is true for the attainment of a suitable compromise between productivity and product quality attributes. While the stabilization problem of continuous exothermic chemical reactors has been recently addressed with rigorous asymptotic‐stability methods, the same kind of studies have not yet been performed for the finite‐time batch reactor case. In this paper, the problem of designing a temperature tracking controller for an exothermic batch reactor, with n species and m reactions, is addressed under the following premises: (i) only the reactor temperature is measured, (ii) the (typically uncertain) reaction rate and heat exchange nonlinear functions are unknown, (iii) the controller must be linear and easy to tune, and (iv) the closed‐loop reactor motion must be stable in a suitable sense. The combination of industrial‐oriented inventory control concepts in conjunction with singular perturbation results yields a linear controller with a combined feedforward‐PI feedback structure, antireset windup scheme, and conventional‐like tuning rules. The controller: (i) tracks, arbitrarily fast and close, a prescribed temperature trajectory, with admissibly deviated concentration motions, and (ii) quickly recovers the behaviour of an exact model‐based nonlinear I/O linearizing controller. The proposed design is put in perspective with the geometric and IMC nonlinear control approaches. Copyright © 2005 John Wiley & Sons, Ltd.