bluuebunny/crossref_metadata_2025_split huggingface dataset:
Eigenschaften von nanoskaligen Aluminiumoxid‐ und Titandioxid‐Partikeln in Nickelelektrolyten
Authors: Oberseider M. , Erler F. , Jakob C. , Lampke T. , Steinhäuser S. , Wielage B. 
Published: June 2003

AbstractDie Untersuchung des Agglomerationsverhaltens von nanoskaligen Partikeln in Abhängigkeit der Konzentration der Einzelbestandteile eines Watts‐Nickelelektrolyten und der mechanischen Konvektion ist Gegenstand dieses Artikels. Ausgehend von der Beschreibung der Messprinzipien werden die Ergebnisse der Zetapotentialmessungen und Bestimmung der Agglomeratgrößen dargestellt, wobei ebenfalls auf die auftretenden Schwierigkeiten bei den Messungen eingegangen wird. Nickelsulfat zeigte die größte Wirkung zur Bildung großer Agglomerate während die Borsäure darauf keinen Einfluss aufwies.
Ergebnisse von Sol‐Gel‐Beschichtungen auf austenitischem CrNi‐Stahl
Authors: Schwarz J. , Svoboda St. , Oertel B. 
Published: June 2003

AbstractDünne Al2O3 – Hartstoffschichten wurden mittels Sol‐Gel‐Verfahren auf austenitischem CrNi‐Stahl präpariert und untersucht.Das Umwandlungsverhalten und die Messungen der Schichteigenspannungen wurden durch Röntgenbeugungsverfahren ermittelt. Ergänzt wurden die Untersuchungen durch Verscheißmessungen.
Nutzung von Werkstoffstrukturgrößen als Messnormale
Authors: Spieß L. , Knedlik Ch. 
Published: June 2003

AbstractMessen von Längen ist ein Vergleichen/Bewerten von erhaltenen Messsignalen mit einem Standard/Kalibriermassstab. Die Nanotechnik erfordert Messgenauigkeiten vom Submeter bis zum Nanometerbereich, d. h. ein Überstreichen von 9 Größenordnungen. Messmarken und mögliche Messnormale werden nach ihren Erfordernissen klassifiziert und auf Anforderungen, Genauigkeit, Stabilität, Datenmengen und Machbarkeit analysiert. Für eine Nanopositionier‐ und –messmaschine werden Vorschläge für eine Realisierbarkeit zusammengefasst.
Characterization of Indium‐Tin‐Oxide Thin Film Microelectrodes for Biomedical Use
Authors: Jakubec A. , Tvarozek V. , Novotny I. , Rehacek V. , Breternitz V. , Knedlik Ch. , Spiess L. 
Published: June 2003

AbstractSelected properties of indium‐tin‐oxide (ITO) films prepared by r.f. diode sputtering have been investigated in consideration of surface morphology, optical properties, crystal structure and phase formation, electrical resistivity and chemical resistance. The ITO films showed low electrical resistivity (6·10‐5Ωm), high optical transmittance (> 80 %) and suitable chemical resistance against selected chemicals during 1 hour.
Einfluss von UV‐Laserparametern auf die geometrische Strukturierung von fotosensitivem Glas
Authors: Brokmann U. , Harnisch A. , Hülsenberg D. 
Published: June 2003

AbstractDer Werkstoff Glas ist zunehmend ein interessanter Konstruktionswerkstoff für die Mikrotechnik. Zur Mikrobearbeitung von fotostrukturierbaren Gläsern wird die Eigenschaft Fotosensibilität im UV‐Bereich ausgenutzt. Als „fotosensibel”︁ gilt ein Glas u. a. dann, wenn es unter Einfluss räumlich begrenzter energiereicher UV‐Strahlung und anschließender thermischer Behandlung nur in den belichteten Bereichen kristallisiert. Die Mikrostrukturierung erfolgt durch anschließendes nasschemisches Ätzen der kristallisierten Bereiche. Die Belichtung fotosensitiver Gläser mittels konventioneller Maskaligner ist gegenwärtig Stand der Technik. Ein alternatives Verfahren dazu stellt die Belichtung mittels UV‐Laserstrahlung dar. Es werden Zusammenhänge zwischen Laserparametern und erzeugten Strukturgeometrien diskutiert.
Transluzente oxidfaserverstärkte Glasmatrix‐Verbundwerkstoffe
Authors: Fehling P. , Hülsenberg D. , Raab D. , Mache Th. , Winkler V. , Kern H. , Stöckel S. , Weise, K. , Marx G. 
Published: June 2003

AbstractDas Ziel der Untersuchungen ist die Entwicklung von transparenten Glasmatrix‐Kompositen. Neben den mechanischen müssen dazu auch die optischen Eigenschaften der Komponenten aneinander angepaßt werden. Der Einfluß unterschiedlicher Faserbeschichtungen (Bornitrid‐, Titandioxid‐Einzelbeschichtung oder Bornitrid/Titandioxid‐Doppelbeschichtung) auf die mechanischen und optischen Eigenschaften von Nextel 440‐Faser verstärktem Glas wird untersucht. Mikromechanische Untersuchungen (push‐in Tests) und 3‐Punktbiegeversuche erbrachten die größte Verbesserung der Bruchzähigkeit für die Verbunde mit Bornitrid/Titandioxid‐doppelbeschichteten Fasern. Die Verbunde mit Bornitrid bzw. Titandioxid Einzelschichten wurden durch Transmissionsmessungen im sichtbaren Spektralbereich charakterisiert.
Magnetische Mikrokomponenten für die Mikroreaktionstechnik
Authors: Halbedel B. , Albrecht A. , Frank Th. , Henkel Th. , Kunze U. , Mayer G. , Schober A. , Wurmus H. 
Published: June 2003

AbstractMiniaturisierung und Parallelität chemischer und molekularbiologischer Prozessen erfordern die Entwicklung neuer μ‐Scale‐Lösungen. Reaktionskammerarrays mit weniger als 1 μl sind bereits verfügbar, jedoch das größere technische Problem, das verbleibt , ist das Handling, vornehmlich der Transfer der Substanzen im nl‐Bereich zwischen den Kammern. Dafür wurde ein neuartiger Lösungsansatz mit magnetischen Funktionskugeln, die Festphasenreaktionen ermöglichen, entwickelt und ein neues Handlingssystem mit magnetischen Transferplatten konzipiert, das einen parallelen und selektiven Substanztransfer auch zwischen miniaturisierten Reaktionskammerarrays mit mehreren tausend Kammern gestattet.
Oberflächenspannungsmesstechnik für den Prozesseinsatz
Authors: Haberland R. , Krause W. 
Published: June 2003

AbstractBei der Reinigung von Oberflächen ist das Einhalten der optimalen Tensidkonzentration für die Prozesssicherheit entscheidend. Die Konzentration der freien Tenside ist messbar, indem die Oberflächenspannung erfasst wird. Die SITA Messtechnik GmbH hat einen neuartigen Sensor auf der Basis der Blasendifferenzdruckmethode entwickelt, der eine kontinuierliche Messung der Oberflächenspannung bei hoher Standzeit ermöglicht. Mit dessen Anwendung zum Überwachen von Reinigungsbädern ergeben sich Einsparpotentiale hinsichtlich Rohstoffeinsatz, Entsorgung und Fehlerfolgekosten.
Simultaneous tridiagonalization of two symmetric matrices
Authors: Garvey Seamus D. , Tisseur Françoise , Friswell Michael I. , Penny John E. T. , Prells Uwe 
Published: June 2003

AbstractWe show how to simultaneously reduce a pair of symmetric matrices to tridiagonal form by congruence transformations. No assumptions are made on the non‐singularity or definiteness of the two matrices. The reduction follows a strategy similar to the one used for the tridiagonalization of a single symmetric matrix via Householder reflectors. Two algorithms are proposed, one using non‐orthogonal rank‐one modifications of the identity matrix and the other, more costly but more stable, using a combination of Householder reflectors and non‐orthogonal rank‐one modifications of the identity matrix with minimal condition numbers. Each of these tridiagonalization processes requires O(n3) arithmetic operations and respects the symmetry of the problem. We illustrate and compare the two algorithms with some numerical experiments. Copyright © 2003 John Wiley & Sons, Ltd.
Symmetric Galerkin BEM for shear deformable plates
Authors: Perez‐Gavilan J. J. , Aliabadi M. H. 
Published: June 2003

AbstractA symmetric Galerkin boundary element formulation is developed for shear deformable plates. A mixed strategy is used for the integration process, i.e. partial regularization using simple solutions followed by a singularity subtraction technique. For the shear equation, full regularization is achieved using new kernel relationships found through a constant shear mode of deformation. Some of the strong singular integrals are avoided altogether by using a modified traction obtained through a very simple variable change; appropriate boundary conditions are defined. Details of the implementation are given and several example problems solved to verify the accuracy of the proposed formulation. Copyright © 2003 John Wiley & Sons, Ltd.
A novel 3D mixed finite‐element model for statics of angle‐ply laminates
Authors: Desai Y. M. , Ramtekkar G. S. , Shah A. H. 
Published: June 2003

AbstractAnalysis of angle‐ply laminates becomes critical and computationally involved because of the presence of extension–shear coupling. A refined three‐dimensional, mixed, 18‐node finite element (FE) model has been developed to analyse angle‐ply laminates under static loading. The minimum potential energy principle has been used for the development of the mixed FE model, where the transverse stress components (τxz, τyz and σz, where z is the thickness direction) have been incorporated as the nodal degrees of freedom, in addition to the three displacement fields. Further, continuity of transverse stress fields through the thickness of the plate and layerwise continuity of displacement fields have been enforced in the formulation. Because all the constitutive and the compatibility conditions have been ensured within the continuum, the present formulation is unique amongst the family of mixed FE models. Results have been obtained for various angle‐ply laminates and compared with analytical and finite‐element solutions, which have been found to be in good agreement with them. Some new results on angle‐ply with clamped–clamped support condition have also been presented to serve as benchmark results. Copyright © 2003 John Wiley & Sons, Ltd.
Checkerboard‐free topology optimization using non‐conforming finite elements
Authors: Jang Gang‐Won , Jeong Je Hyun , Kim Yoon Young , Sheen Dongwoo , Park Chunjae , Kim Myoung‐Nyoun 
Published: June 2003

AbstractThe objective of the present study is to show that the numerical instability characterized by checkerboard patterns can be completely controlled when non‐conforming four‐node finite elements are employed. Since the convergence of the non‐conforming finite element is independent of the Lamé parameters, the stiffness of the non‐conforming element exhibits correct limiting behaviour, which is desirable in prohibiting the unwanted formation of checkerboards in topology optimization. We employ the homogenization method to show the checkerboard‐free property of the non‐conforming element in topology optimization problems and verify it with three typical optimization examples. Copyright © 2003 John Wiley & Sons, Ltd.
A discontinuous Galerkin finite element method for dynamic and wave propagation problems in non‐linear solids and saturated porous media
Authors: Li Xikui , Yao Dongmei , Lewis R. W. 
Published: June 2003

AbstractA time‐discontinuous Galerkin finite element method (DGFEM) for dynamics and wave propagation in non‐linear solids and saturated porous media is presented. The main distinct characteristic of the proposed DGFEM is that the specific P3–P1 interpolation approximation, which uses piecewise cubic (Hermite's polynomial) and linear interpolations for both displacements and velocities, in the time domain is particularly proposed. Consequently, continuity of the displacement vector at each discrete time instant is exactly ensured, whereas discontinuity of the velocity vector at the discrete time levels still remains. The computational cost is then obviously saved, particularly in the materially non‐linear problems, as compared with that required for the existing DGFEM. Both the implicit and explicit algorithms are developed to solve the derived formulations for linear and materially non‐linear problems. Numerical results illustrate good performance of the present method in eliminating spurious numerical oscillations and in providing much more accurate solutions over the traditional Galerkin finite element method using the Newmark algorithm in the time domain. Copyright © 2003 John Wiley & Sons, Ltd.
A gradientless technique for optimal distribution of piezoelectric material for structural control
Authors: Mukherjee A. , Joshi S. P. 
Published: June 2003

AbstractApplication of smart piezoelectric materials in structural control is gaining momentum. Optimum placement and actuation of the smart material is an aspect of paramount importance in such structures. In this paper, we present an iterative technique to optimize the shape of piezoelectric actuators in order to achieve the desired shape of the structure. A C0‐continuous eight‐node plate finite element with five degrees of freedom is employed. A gradientless shape design procedure based on the residual voltages is developed. It aims at minimizing the quadratic measure of the global displacement residual error between the desired and the current structural configuration. The actuators gradually adapt to a shape that is most efficient in resisting the external excitation. The present technique can be well suited for any static and time‐varying excitation. In vibration control it is often necessary to create modal sensors and actuators in order to observe or excite some specific modes. Such modal sensors and actuators alleviate spillover problems and thus they avoid exhaustive signal processing. Several numerical examples for static as well as dynamic cases are presented to demonstrate the efficacy of the present technique. Copyright © 2003 John Wiley & Sons, Ltd.
Numerical simulation of convective heat and mass transfer in banks of tubes
Authors: Comini G. , Croce G. 
Published: June 2003

AbstractThis paper studies convective heat and mass transfer in laminar flows of humid air through banks of tubes. The flow structure on the airside is spatially periodic, with fully developed conditions prevailing after a short distance from the inlet section. In numerical simulations, periodicities in the velocity, temperature and mass concentration fields are taken into account to reduce the computational domain, both in the entrance region and in the fully developed region. The approach followed is completely general, even if the finite element method is used in the discretization process. In the application section, velocity, temperature and mass concentration fields are computed for a bank of tubes in a staggered arrangement. Quantitative results are also obtained for apparent friction factors, Nusselt numbers, Sherwood numbers and ratios between Colburn factors for heat and mass transfer. Copyright © 2003 John Wiley & Sons, Ltd.
Evidence of interpersonal violence at the Chalcolithic village of Shiqmim (Israel)
Authors: Dawson L. , Levy T. E. , Smith P. 
Published: June 2003

AbstractThree circumscribed depressed fractures were found on the skull of an adolescent boy recovered from a primary intramural burial at the Chalcolithic site of Shiqmim, northern Negev, Israel dated to (∼4500–3200 BCE). The fractures were located on the left side and back of the skull. They are circular in outline and have sharp margins containing numerous small bone fragments. These indicate that the skull was fractured when the bone was still fresh and were the probable cause of death. The location of the fractured areas is typical of blows inflicted by a right‐handed individual in face‐to‐face conflict. The size and shape of the fractures, suggests that they were inflicted by a blunt instrument, possibly a mace head. The absence of any signs of healing or infection indicates that all fractures occurred within a short space of time and resulted in death. Neither biological characteristics nor burial pattern show any unique features that distinguish this individual from others recovered at this site. Copyright © 2003 John Wiley & Sons, Ltd.
The application of ancient DNA analysis to identify neolithic caprinae: a case study from the site of Hatoula, Israel
Authors: Kahila Bar‐Gal Gila , Ducos Pierre , Kolska Horwitz Liora 
Published: June 2003

AbstractThe evidence for wild sheep (Ovis orientalis) in archaeological sites from the southern Levant is examined through the application of ancient DNA analysis to specimens from the Pre‐Pottery Neolithic A (8300–7500 uncal. BC) site of Hatoula, Israel. The results indicate that at least one of the bones from this site, previously identified as sheep, is in fact goat. To date this is the earliest faunal sample to have yielded DNA in the region. This study highlights the problems in applying morphological criteria to distinguish between caprine species, and illustrates how ancient DNA analysis can serve as a powerful tool in resolving questions of species attribution. Copyright © 2003 John Wiley & Sons, Ltd.
Congenital absence of the patella in an Anglo‐Saxon skeleton
Authors: Patrick P. , Waldron T. 
Published: June 2003

AbstractA skeleton of a young Anglo‐Saxon woman aged about 25 years at the time of death is described. The distal femoral articulation was in two distinct parts separated by a deep groove in which the tendon of quadriceps femoris would have lain. The medial condyle of the femur was smaller than normal and there was no patellar surface on the anterior part of the articulation. The woman was of normal stature (1.53 ± 0.04 m) and no other abnormalities were found in the skeleton. It was considered that these findings were consistent with a diagnosis of congenital absence of the patella. This is the earliest recorded case of this condition. Copyright © 2003 John Wiley & Sons, Ltd.
Chemical Kinetics and Heat Transfer Issues for a Safe Bench Scale Production of Partially Triazole Substituted Glycidyl Azide Polymer (GAP)
Authors: Dubois Charles , Désilets Sylvain , Nadeau Gaston , Gagnon Nicole 
Published: June 2003

AbstractThe reaction of azido polymers with double and triple bonds of light olefins can lead to triazole and aziridine cycles formation on the azide bearing sites of the polymer. An experimental investigation of the burning behaviour of these modified polymers has shown that triazole substituted GAPs exhibit a higher burning rate at low pressure, which may be a desirable characteristic for ducted rocket applications. However, the chemical reaction of interest is highly exothermic and as such, it represents a significant safety risk when conducted in bulk. In order to reduce this risk, we have assessed the chemical kinetics of triazole formation by NMR spectroscopy and linked this information with DSC measurements to produce a safe procedure for the synthesis of GAP‐triazole polymer in a chemical reactor.
Hazard Characterization of Aluminum Nanopowder Compositions
Authors: Jones David E. G. , Turcotte Richard , Fouchard Robert C. , Kwok Queenie S. M. , Turcotte Anne‐Marie , Abdel‐Qader Zainab 
Published: June 2003

AbstractThe thermal behaviour in air of two Al nanopowders, Alss and Alsstef, a Teflon coated version of Alss, was determined using DSC, TG‐DTA and accelerating rate calorimetry (ARC). Compared to two larger Al nanopowders, for which hazards results have been reported, Alss and Alsstef are less reactive in air, possibly due to the nature of the passivating and coating layers. The stability of Alss and Alsstef in a wet environment was also investigated using ARC. Alss is very reactive with water, which could lead to a problem of aging in a humid atmosphere. The ”coating” of Alsstef significantly reduces the reactivity of Alss with water. Outgassing behaviour of mixtures of ADN, GAP and various Al powders was investigated using TG‐DTA‐FTIR‐MS. No chemical interactions were observed between ADN/Al, GAP/Al and ADN/GAP. The effect of the addition of Al nanopowders on the thermal decomposition of ADN and GAP was studied using ARC. Al nanopowders had a minor effect on the thermal stability of ADN, while the addition of Alss and Alsstef lowered the onset temperature of GAP. The electrostatic discharge (ESD), impact and friction sensitivities of Al nanopowders and their mixtures with ADN and GAP were also determined. Al nanopowders appear to sensitize ADN to ESD, impact and friction.
A Simple Method for the Purification of Crude Hexanitrohexaazaisowurtzitane (HNIW or CL20)
Authors: Bellamy Anthony J. 
Published: June 2003

AbstractA simple method for purifying crude hexanitrohexaazaisowurtzitane (HNIW or CL20) to analytical purity is described. This involves filtering a solution of HNIW in heptane / ethyl acetate through a column of Darco activated carbon type G‐60 (∼20 g carbon/g HNIW). The method works extremely well for HNIW derived from 4,10‐diformyl‐2,6,8,12‐tetraacetylhexaazaisowurtzitane (final purity>99.95%, ∼90% recovery), and reasonably well for HNIW derived from 4,10‐dibenzyl‐2,6,8,12‐tetraacetylhexaazaisowurtzitane.
Structure and Bonding in 2‐Diazo‐4,6‐Dinitrophenol (DDNP)
Authors: Holl Gerhard , Klapötke Thomas M. , Polborn Kurt , Rienäcker Claudia 
Published: June 2003

AbstractThe structure and bonding in 2‐diazo‐4,6‐dinitrophenol (DDNP) is discussed on the basis of quantitative molecular orbital (MO) calculations at the density functional theory (DFT) level using the natural bond orbital analysis (NBO). Qualitative valence bond theory (VB) was used to generate an increased VB structure for DDNP. The increased‐valence structure is better in accordance with the computed and observed (X‐ray) geometry than is the NBO analysis.
The Use of theTrifluoroacetyl Protecting Group in the Synthesis of Mono‐ (4) and Di‐Amines (4,10) in the Polynitrohexaazaisowurtzitane Series
Authors: Bellamy Anthony J. , MacCuish Alistair , Golding Peter 
Published: June 2003

AbstractThe first rational synthesis of the mono‐amine 2,6,8,10,12‐pentanitro‐2,4,6,8,10,12‐hexaazaisowurtzitane (II) and the di‐amine 2,6,8,12‐tetranitro‐2,4,6,8,10,12‐hexaazaisowurtzitane (III) is described. Both syntheses exploit the selectivity, under nitrolysis conditions, between an N‐acetyl group and an N‐trifluoroacetyl group, and the ease with which an N‐trifluoroacetyl group can be hydrolytically removed.
Peptide related drug research
Authors: Bajusz Sándor 
Published: June 2003

AbstractDrug discovery directed peptide research has been pursued at the IVAX Drug Research Institute (formerly Institute for Drug Research) (IDR) since the mid 1950s. Outlined are the main projects and the most significant results, which include the first synthesis of human ACTH, the discovery of GYKI‐14 166, the prototype of peptide inhibitors of thrombin, a stable anticoagulant, efegatran GYKI‐14 766, and their dual acting analogues. The identification of an agonist analogue of LHRH leading to Cetrorelix, an LHRH antagonist now in clinical use, is also presented. Copyright © 2003 European Peptide Society and John Wiley & Sons, Ltd.
Synthetic formyl tripeptide chemoattractants: a Cα, α‐dialkylated, amphiphilic glycyl residue at position 1
Authors: Witkowska Renata , Zabrocki Janusz , Spisani Susanna , Sofia Falzarano Maria , Toniolo Claudio , Formaggio Fernando 
Published: June 2003

AbstractThe two diastereomeric tripeptides f‐(S)‐HmMet‐Leu‐Phe‐OMe and f‐(R)‐HmMet‐Leu‐Phe‐OMe, analogues of the prototypical chemoattractant f‐Met‐Leu‐Phe‐OH, were synthesized in solution by classical methods and fully characterized. A conformational study was performed in solution by 1H‐NMR. Concomitantly, the two peptides were tested for their ability to induce chemotaxis, superoxide anion production and lysozyme secretion from human neutrophils. The conformational and biological data are discussed with regard to the proposed model of the chemotactic receptor on neutrophils. Copyright © 2003 European Peptide Society and John Wiley & Sons, Ltd.