bluuebunny/crossref_metadata_2025_split huggingface dataset:
The CIP method embedded in finite element discretizations of incompressible fluid flows
Authors: Banijamali Bahareh , Bathe Klaus‐Jürgen 
Published: December 2006

AbstractQuite effective low‐order finite element and finite volume methods for incompressible fluid flows have been established and are widely used. However, higher‐order finite element methods that are stable, have high accuracy and are computationally efficient are still sought. Such discretization schemes could be particularly useful to establish error estimates in numerical solutions of fluid flows. The objective of this paper is to report on a study in which the cubic interpolated polynomial (CIP) method is embedded into 4‐node and 9‐node finite element discretizations of 2D flows in order to stabilize the convective terms. To illustrate the capabilities of the formulations, the results obtained in the solution of the driven flow square cavity problem are given. Copyright © 2006 John Wiley & Sons, Ltd.
A natural neighbour‐based moving least‐squares approach for the element‐free Galerkin method
Authors: Most Thomas 
Published: December 2006

AbstractThe element‐free Galerkin method (EFG) and the natural element method (NEM) are two well known and widely used meshless methods. Whereas the EFG method can represent moving boundaries like cracks only by modifying the weighting functions the NEM requires an adaptation of the nodal set‐up. But on the other hand the NEM is computationally more efficient than EFG. In this paper a new concept for the automatic adjustment of nodal influence domains in the EFG method is presented in order to obtain an efficiency similar to the NEM. This concept is based on the definition of natural neighbours for each meshless node which can be determined from a Voronoi diagram of the nodal set‐up. In this approach adapted nodal influence domains are obtained by interpolating the distances to the natural neighbours depending on the direction. In the paper we show that this concept leads, especially for problems with grading node density, to a reduced number of influencing nodes at the interpolation points and consequently a significant reduction of the numerical effort. Copyright © 2006 John Wiley & Sons, Ltd.
Arrays of dynamic circular loads moving on an infinite plate
Authors: Sun Lu , Luo Feiquan 
Published: December 2006

AbstractSteady‐state dynamic responses of a Kirchhoff plate resting on a viscoelastic Winkler foundation subject to arrays of moving constant and harmonic loads with uniform circular distribution is studied in this paper using Fourier transform and generalized Duhamel's integral. A computational schema is constructed based on a two‐fold fast Fourier transform in a moving co‐ordinate system. Numerical case studies using a single moving load as well as four moving loads mimicking four wheel‐loads of a moving vehicle are conducted. Parameters of the plate are typical values of structural and material properties of highway pavements. Displacement responses of the plate to these five loading speeds seem to be very close to each other, though the vertical velocity and acceleration responses show considerable differences. The effect of load frequency on amplitude of response of plate is insignificant for parameters used in this study. Copyright © 2006 John Wiley & Sons, Ltd.
Non‐matching mesh gluing by meshless interpolation—an alternative to Lagrange multipliers
Authors: Tian Rong , Yagawa Genki 
Published: December 2006

AbstractRewards of using non‐matching meshes are great in many aspects: sub‐meshing a complex structure in a sub‐structure‐wise manner separately and/or in parallel; selective local refinement; unlimited scalability guarantee for generating meshes in increasingly large‐scale finite element simulation, etc. However, when meshes do not match, a gluing algorithm is required to enforce inter‐domain continuity. ‘Non‐matching’ terminologically originates from mesh discretization in nature, and the non‐matching mesh issue is therefore avoidable or does not exist in a node‐based or meshless discretization in meshless methods. Motivated by this, a gluing algorithm is developed based on meshless interpolation. The gluing is accomplished by continuous trial and test functions across non‐matching meshes constructed using nodes only. The developed gluing algorithm is tested in static and wave propagation problems in two and three dimensions. It is demonstrated that the gluing algorithm does not deteriorate convergence and accuracy compared with the one‐piece conforming mesh. Compared with Lagrange multiplier gluing—one of the most common approaches—the current algorithm has two significant benefits: (1) easier implementation in any dimension and (2) positive definite banded system matrices, not acting against equation solvers, and hence better suited for large‐scale finite element analysis. Copyright © 2006 John Wiley & Sons, Ltd.
Study of EDL effect on 3‐D developing flow in microchannel with Poisson–Boltzmann and Nernst–Planck models
Authors: Ng E. Y. K. , Tan S. T. 
Published: December 2006

AbstractMicrochannels have been suggested to be a very effective heat transfer device. However, the electrical double layer (EDL) effect in a microchannel is anticipated to be significant. In this paper, two EDL models coupled with Navier–Stokes equations were used to compute a 3‐D developing microchannel flow. The Poisson–Boltzmann model (PBM) has been proven to be a promising tool in studying the EDL effect for developed microchannel flow, with respect to its accuracy and efficiency. However, it was commended that the assumption of Boltzmann distribution in PBM, for electric ion concentration distribution in particular was questionable in the developing flow. Nernst–Planck model (NPM), with its two extra partial differential equations (PDEs) to predict the ion concentration distribution, was reported to be a more appropriate model for developing microchannel flow though increased RAM and CPU were needed as compared to the PBM. The governing equations for both models were discretized for developing rectangular microchannel flows in Cartesians co‐ordinate. An additional source term, related to the electric potential, resulting from the EDL effect was introduced in the conventional z‐axis momentum equation as a body force, thereby modifying the flow characteristics. A finite‐volume scheme was used to solve the PDEs. The discrepancy in the results predicted by the two models was more dominant in the near‐wall region and not in the mainstream region. However, the performance of the microchannel was significantly affected by the EDL effect. An increase in Schmidt number will lead to decrease in friction coefficient. For the effect of aspect ratios (ARs), the discrepancy of f Re and Nu values for different ARs was obvious. Therefore, a 3‐D analysis was concluded to be important and necessary for investigating the EDL effect in microchannels. Copyright © 2006 John Wiley & Sons, Ltd.
Poly(propylene)/aspen/liquid polybutadiene composites: maximization of impact strength, tensile and modulus by statistical experimental design
Authors: Kokta B. V. , Michalkova D. , Fortelny I. , Krulis Z. 
Published: December 2006

AbstractA systematic study of the effect of concentration of maleated poly(propylene) (MAPP), dicumyl peroxide (DCP), polyisobutadiene isocyanate (PBNCO) and fiber content on the mechanical properties of aspen‐poly(propylene)(PP) composite was undertaken with the objective to maintain or increase the impact strength without losing tensile strength reinforcement. Using STAGRAPHIC Plus it was possible to determine the optimum concentration of additives and to maximize both the impact as well as tensile properties well above that of pure PP. Copyright © 2006 John Wiley & Sons, Ltd.
Preimplantation genetic diagnosis for myotonic dystrophy type 1: detection of crossover between the gene and the linked marker APOC2
Authors: Kakourou Georgia , Dhanjal Seema , Daphnis Danny , Doshi Alpesh , Nuttall Sarah , Gotts Sarah , Serhal Paul , Delhanty Joy , Harper Joyce , SenGupta Sioban 
Published: December 2006

AbstractObjectiveTo report two cases of preimplantation genetic diagnosis (PGD) for myotonic dystrophy type I (DM1) where cross‐over between the DMPK locus and a linked polymorphic marker APOC2 was detected.MethodsEmbryos from in vitro fertilisation (IVF) were biopsied at day 3 of development and single blastomeres collected. Diagnosis was performed by duplex or triplex fluorescent‐polymerase chain reaction (F‐PCR) to amplify DMPK and APOC2 loci, or DMPK with APOC2 and D19S112 polymorphic markers.ResultsA total of 22 oocytes were retrieved from the two patients, 20 were inseminated of which 15 fertilized (75%) and were suitable for biopsy on day 3. A diagnosis was obtained for 12 embryos (80%) and was confirmed in all un‐transferred embryos. Crossover between DM1 and APOC2 was detected in two embryos from the two different couples. Transfer of two embryos took place in both cases resulting in two pregnancies. Each couple have had a healthy baby.ConclusionThe above cases highlight the importance of using more than one linked polymorphic marker in PGD‐PCR protocols and emphasize the danger of using APOC2 as the sole marker to identify the DM1 mutation. Copyright © 2006 John Wiley & Sons, Ltd.
On the stereomicrostructure‐based mechanisms of physical properties of poly(methyl methacrylate): 1. space charge behaviour and physical ageing
Authors: Guarrotxena Nekane , de Frutos Manuel 
Published: December 2006

AbstractThree samples of poly(methyl methacrylate) (PMMA) were characterized after careful purification. Their composition in terms of some repeating stereosequences, especially mmr termini of isotactic sequences, was determined. Their space charge behaviour was analysed using the thermal step (TS) method. A correlation between the electrical current intensity, as given by the TS method, and the stereochemical microstructure content in each sample was evidenced. The results are explained in the light of previous data on the specific microstructures present in the samples at different contents. The physical ageing of the samples was studied, quantitatively, through differential scanning calorimetry measurements prior to and after equally performed thermal treatments of the samples. The corresponding values of the loss of enthalpy agree with the content of mmr tetrad termini of isotactic sequences. The results are analysed on the basis of the differences in stereochemical composition of the samples. The results give further evidence of the role of some definite stereosequences in physical properties as proposed in earlier works on poly(vinyl chloride) and polypropylene. Copyright © 2006 Society of Chemical Industry
Bone cell attachment and growth on well‐characterized chitosan films
Authors: Hamilton Virginia , Yuan Youling , Rigney Debbie A , Chesnutt Betsy M , Puckett Aaron D , Ong Joo L , Yang Yunzhi , Haggard Warren O , Elder Steven H , Bumgardner Joel D 
Published: December 2006

AbstractChitosan has been widely researched for bone tissue and implant applications. While initial results are promising, there are inconsistent reports regarding the biological responses. This may be due to inadequate evaluation of chitosan material properties. This study evaluated normal human osteoblast precursor cell attachment and proliferation on a series of well‐characterized chitosan films. The chitosan films exhibited a range of properties: 76–96% degree of de‐acetylation (DDA), 2400–8200 kDa viscosity‐average molecular weight, 62–90° contact angle, 0.24–2.46% residual ash, 5.3–287 µg cm−2 residual protein and 23–40% crystallinity. There was no trend or correlation between DDA, crystallinity, contact angle, molecular weight, residual ash or protein content and the attachment or growth of bone cells on chitosan films. All films supported higher levels of bone cell proliferation than tissue culture plastic, which supports the general hypothesis that chitosans are osteocompatible. The 78 and 92% DDA chitosan films supported the most cell proliferation, approximately 16 times that of tissue culture plastic controls, but no chitosan physiochemical property correlated with the increased cell growth. The lack of correlation is hindered since more than one physiochemical property changed for each chitosan material. Data do indicate that there may be much variability in chitosan materials, and this variability may make understanding and comparing biological performance of chitosan materials difficult. These results highlight the need for systematic characterizations of chitosan materials for predictable biomedical applications. Copyright © 2006 Society of Chemical Industry
Study of the effect of hyperbranched polyols on cationic UV curable coating properties
Authors: Chen Zhigang , Webster Dean C 
Published: December 2006

AbstractCycloaliphatic epoxide‐based cationic UV curable coatings containing three different hyperbranched polyols (HBPs) were systematically formulated and characterized. Polyether polyols were found to deter epoxide conversion under low UV intensity. For high UV intensity, the cycloaliphatic epoxide conversion increased with polyol content. Coatings with HBPs had better flexibility and solvent resistance than those containing a reference triol. Compared to the triol and polyester HBPs, polyether HBPs imparted lower Tg and hardness but a better flexibilizing effect to the coatings. At higher R values, the coating solvent resistance decreased except for those with one polyether HBP.A two‐peak phenomenon was discovered in the residual thermal reaction heat curve after photoDSC experiments. These two peaks were found to be related to the thermal relaxation behavior of the photocured inhomogeneous film, and the reactivation and reaction of the ‘trapped living cationic species’. The capability of the polyol to lower the high‐temperature‐peak temperature corresponded well with the flexibilizing ability. Copyright © 2006 Society of Chemical Industry
Dornröschen und Mauerblümchen: Nachzügler und vergessene Arbeiten in der Physik
Authors: Marx Werner 
Published: December 2006

AbstractWissenschaftliche Publikationen werden von Fachkollegen im Durchschnitt in den ersten drei Jahren am häufigsten zitiert, danach fällt die Rate rasch ab. Es gibt jedoch Arbeiten, die erst nach vielen Jahren oder Jahrzehnten ihre volle Wirkung entfalten. Berühmte Beispiele für solche “Dörnröschen” sind Walter Kohns und Lu Shams Pionierarbeiten über die Dichtefunktionaltheorie oder die EPR‐Arbeit von Albert Einstein, Boris Podolsky und Nathan Rosen. Manche Pionierarbeiten waren jedoch ihrer Zeit zu weit voraus und gerieten wie ihre Verfasser in Vergessenheit. Ein Beispiel für ein solches “Mauerblümchen” ist die Arbeit von Ralph Alpher und Robert Herman von 1949 mit der ersten theoretischen Vorhersage der kosmischen Hintergrundstrahlung.
Jeder Schuss ein Treffer: Physik und Treffsicherheit beim Sport
Authors: Mathelitsch Leopold , Thaller Sigrid 
Published: December 2006

AbstractBei Sportarten, in denen es auf Treffsicherheit ankommt, zählen nicht Kraft oder Schnelligkeit, sondern präzise Bewegungen. Beim Basketball erhöht eine geringe Fluggeschwindigkeit gepaart mit einem steileren Flugwinkel die Trefferchance. Bei Schießsportarten kommt es auch darauf an, wie groß der Schütze die Zielscheibe tatsächlich sieht. Dartprofis neigen sich vor, um die Schussdistanz erlaubt zu reduzieren. Beim Bowling kann der Ball nur dann alle Pins auf einen Schlag abräumen, wenn er auf einer perfekt gekrümmten Bahn läuft. Das ermöglicht ein Gleitfilm aus Öl auf der Bahn, dessen Dicke zum Ziel hin abnimmt.
Der falsche Knick im Licht: Materialien mit negativem Brechungsindex
Authors: Dolling Gunnar , Wegener Martin , Linden Stefan 
Published: December 2006

AbstractDurch Maßschneidern funktioneller nanoskaliger Baugruppen photonische Atome, dicht zusammengepackt zu einem effektiven Medium, können künstliche Materialien mit qualitativ neuartigen optischen Eigenschaften hergestellt werden. Ein Beispiel sind Materialien mit einer negativen Brechzahl. Die Strahlen‐ und Wellenoptik dieser Materialien steckt voller Überraschungen, wie bereits einfache computergenerierte Abbildungen und erste Experimente zeigen.
Wasser auf dem Mars: Neue Ergebnisse der Mars‐Rover und Raumsonden
Authors: Hauber Ernst 
Published: December 2006

AbstractDer NASA‐Rover Opportunity fand in Meridiani Planum morphologische, chemische und mineralogische Hinweise auf ehemaliges Wasser an der Oberfläche. Die Analysen weisen auf ein insgesamt trockenes Klima hin, in dem episodisch salziges Wasser in einer sauren und oxidierenden Umgebung vorhanden war. Die besten derzeitigen Analogien auf der Erde sind möglicherweise saure Salzseen in Südwestaustralien, die durch kurzzeitige Überflutung, Verdunstung und nachfolgende Austrocknung entstehen. Die Ergebnisse der ESA‐Mission Mars Express unterstützen die Ergebnisse von Opportunity durch den Nachweis von Tonmineralen und Sulfaten, deren Bildung ebenfalls Wasser erfordert. Das Klima auf dem Mars scheint nach einem relativ feuchten Beginn vor etwa 3,8 Milliarden Jahren zunehmend trockener geworden zu sein.
Herzdiagnose mit Spins: Magnetokardiographie mit optisch gepumpten Magnetometern
Authors: Bison Georg , Weis Antoine 
Published: December 2006

AbstractDie Magnetokardiographie (MKG) misst das extrem schwache Magnetfeld der Herzmuskeln mit hoch empfindlichen Sensoren. Es kann verschiedene Herzkrankheiten wesentlich zuverlässiger diagnostizieren als etablierte Verfahren. Ihr heutiger Nachteil liegt in der Verwendung von SQUID‐Sensoren. Diese müssen auf Temperaturen von 4 K gekühlt werden, was hohe Anschaffungs‐ und Betriebskosten verursacht. Optisch gepumpte Magnetometer könnten der MKG zum Durchbruch in der Praxis verhelfen. Diese Sensoren arbeiten bei Raumtemperatur, was den technischen Aufwand und die Kosten erheblich reduziert. Ein Demonstrationsaufbau an der Universität Fribourg zeigt, dass die Methode zuverlässig funktioniert.
Das Bild vom Bild – der Zauberspiegel Mirage. Spielwiese
Authors: Ucke Christian 
Published: December 2006

AbstractDer Zauberspiegel, Mirage genannt, besteht aus zwei gleichen, annähernd parabolischen Hohlspiegeln. Diese liegen mit der Öffnung aufeinander. Der obere Spiegel hat ein zentrales Loch, in dem zwei reelle Bilder eines Gegenstandes erscheinen, die man auf den ersten Blick nicht von der Wirklichkeit unterscheiden kann. Der Gegenstand selbst befindet sich am Boden des unteren Spiegels. Mit den Gesetzen der geometrischen Optik lässt sich dieses Phänomen erklären.
Das Deutsche Museum in München
Authors: Teichmann Jürgen 
Published: December 2006

AbstractDie Wurzeln der heutigen Science Center in Deutschland finden sich im Deutschen Museum in München. Es wurde 1903 gegründet, geistiger Vater und ideenreicher hartnäckiger Organisator war der Bau‐ und Elektroingenieur Oskar von Miller. Das damals neuartige Konzept sah vor, nicht nur die Geschichte von “Meisterwerken” zu präsentieren, sondern Wissenschaft und Technik mit Vorführungen, eigenen Experimenten der Besucher und neuen Medien dem Volk nahe zu bringen. Ein bis heute erfolgreiches Konzept.
Nicht leicht zu durchschauende Lichtgitter
Authors: Schlichting H. Joachim 
Published: December 2006

AbstractEin Spaziergang am Morgen, wenn das Wasser des Teichs noch leicht vom Nebel der kühlen Nacht verhangen ist, gibt manchmal zu einem eindrucksvollen Lichtschauspiel Anlass. Wenn die Sonne sich nämlich langsam Bahn bricht und ihr Licht an dem in der kühlen Nacht entstandenen Nebel gestreut wird, können unter günstigen Bedingungen interessante, auf den ersten Blick nicht zu durchschauende Lichtgitter entstehen.
Kolloquium bei Tee und Gebäck
Authors: Loos Andreas 
Published: December 2006

AbstractAls der Junge in Berlin zur Welt kommt, geben ihm seine jüdischen Eltern die Vornamen Joseph Meyer. Doch als der Sohn fünf Jahre alt ist, beschließt die Familie zu konvertieren. Zusammen mit seinem Vater und vier Brüdern wird der Junge christlich getauft und erhält zwei neue Vornamen. Das behütet ihn vor der Diskriminierung von Juden.
Zergeht im Mund und nicht im Glas
Authors: Vilgis Thomas 
Published: December 2006

AbstractWenn Sie Ihren Gästen eine kleine Überraschung bieten möchten, dann servieren Sie Ihren Campari‐Orange doch einmal als fest‐flüssiges Zweiphasensystem: Campari‐Perlen schwimmen im Orangensaft, mischen sich aber nicht mit ihm. Kaum zu glauben, aber die Physik der weichen Materie macht es möglich.
Feinheiten im Sonarsystem von Fledermäusen
Authors: Müller Rolf 
Published: December 2006

AbstractStrukturen in den extrem faltigen Gesichtern von Fledermäusen können eine physikalische Funktion haben: Sie sind Teil des Sonarsystems, mit dem sich die Tiere orientieren. Numerische Verfahren zeigen, wie diese Strukturen die ausgesandten und empfangenen Ultraschallfelder beeinflussen.
KATRIN unterwegs
Authors: Bührke Thomas 
Published: December 2006

AbstractEnde November erhielt das Forschungszentrum Karlsruhe eine außergewöhnlich voluminöse Fracht: Das Hauptspektrometer des Karlsruher Tritium Neutrino Experimentes KATRIN. Gebaut wurde es im bayerischen Deggendorf. Doch wegen der gewaltigen Länge von 24 Metern, einem Durchmesser von 10 Metern und einem Gewicht von 200 Tonnen kam der Transport über Land nicht in Frage. Stattdessen ging das Spektrometer auf eine 8800 km lange Reise.
Androgen‐insensitive prostate cancer cells transiently respond to castration treatment when growing in an androgen‐dependent prostate environment
Authors: Halin Sofia , Hammarsten Peter , Wikström Pernilla , Bergh Anders 
Published: December 2006

AbstractBACKGROUNDCastration‐induced involution of the normal prostate is caused by primary effects in the prostate stroma and vasculature, but if this is the case also in tumors is unknown.METHODSAndrogen‐independent AT‐1 prostate tumor cells were therefore injected into the ventral prostate (VP) in Copenhagen rats. Seven days later when the growing tumor was surrounded by normal VP tissue the rats were castrated and the effect examined 3 and 7 days later.RESULTSCastration reduced vascular density in the surrounding VP tissue and this was accompanied by tumor cell hypoxia, apoptosis, and temporarily retarded tumor growth. Castration‐induced VP tissue regression occurred more rapidly in the contra‐lateral than in the tumor‐bearing lobe.CONCLUSIONSAndrogen‐independent tumor cell respond to castration when growing in an androgen‐dependent environment. The presence of a tumor influences the castration response in the surrounding normal tissue. The microenvironment determines how prostate epithelial cells respond to castration. Prostate 67: 370–377, 2007. © 2006 Wiley‐Liss, Inc.
Genomic scan of 12 hereditary prostate cancer families having an occurrence of pancreas cancer
Authors: Pierce Brandon L. , Friedrichsen‐Karyadi Danielle M. , McIntosh Laura , Deutsch Kerry , Hood Lee , Ostrander Elaine A. , Austin Melissa A. , Stanford Janet L. 
Published: December 2006

AbstractBACKGROUNDProstate cancer is a genetically heterogeneous disease. Using the occurrence of other cancers in hereditary prostate cancer (HPC) families is a promising strategy for developing genetically homogeneous data sets that can enhance the ability to identify susceptibility loci using linkage analysis.METHODSTwelve HPC families with the co‐occurrence of adenocarcinoma of the pancreas were selected from the Prostate Cancer Genetic Research Study (PROGRESS). Non‐parametric linkage analysis for a prostate/pancreas cancer susceptibility phenotype was performed using 441 genome‐wide microsatellite markers.RESULTSNo statistically significant linkage signal was detected in this analysis. The strongest linkage signals, as measured by Kong and Cox LOD score (KC LOD), were observed on chromosomes 2q37.2‐q37.3 (KC LOD = 1.01; P = 0.02) and 16q23.2 (KC LOC = 1.05; P = 0.01).CONCLUSIONSDespite the lack of statistically significant findings, four chromosomal regions, three of which (2q, 16q, 17q) were previously noted as harboring potential susceptibility loci, showed suggestive linkage results in this scan. Prostate 67: 410–415, 2007. © 2006 Wiley‐Liss, Inc.