bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hysteretic Friction of a Sliding Rubber Element
Authors: Lindner Markus , Sextro Walter , Popp Karl 
Published: November 2004

AbstractFriction, especially friction of elastomers, can cause acoustic problems like noise, squeal and comfort drawbacks like vibrations and wear. Therefore, rubber friction affects the function of many products in technical applications, e.g. seals, belts and tires. It can be classified according to different physical phenomena like adhesion, hysteresis, cohesion and viscous friction, see [3]. The topic of this paper is hysteresis friction of rubber that is caused by the energy dissipation due to internal material damping during the process of deformation. The deformation itself occurs during the sliding of a rubber element across the micro‐scaled asperities of a rough surface. In this paper, the sliding process of a rubber element over real surfaces is simulated in time domain and compared to experiments. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nichtlineare Schwingungs‐ und Stabilitätsanalysen für Seile
Authors: Thalheim J.‐U. , Heinen A. H. 
Published: November 2004

AbstractZur wirklichkeitsnahen Erfassung räumlicher Seilschwingungen ist es häufig notwendig, numerische Analysen auf der Basis nichtlinearer Bewegungsgleichungen durchzuführen. Insbesondere ist diese Vorgehensweise notwendig zur richtigen Erfassung von Instabilitätserscheinungen bei Seilkonstruktionen. Solche Instabilitätsphänomene sind z.B. bei Schrägseilbrücken infolge von Bewegungen der Pylone und des Fahrbahnträgers beobachtet worden (vgl. [5]). Ziel dieser Abhandlung ist es, mit nichtlinearen Seil‐ und Stabilitätsgleichungen, die im Vergleich zu Formulierungen in der Literatur [3]eine einfachere Struktur aufweisen, Schwingungs‐ und Stabilitätsuntersuchungen durchzuführen und die Ergebnisse ‐ soweit möglich ‐ mit Versuchsergebnissen zu vergleichen. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stoßsimulation mittels einseitiger Feder‐Dämpfer Kontakte
Authors: Waltersberger Bernd , Keppler Rainer , Wauer Jörg 
Published: November 2004

AbstractDie Verwendung von Feder‐Dämpfer Kontaktmodellen bei der Stoßsimulation ist häufig kontinuumsmechanisch begründet oder beispielsweise motiviert durch die Verwendung von Penalty Verfahren zur rechentechnischen Behandlung der Kontaktnebenbedingung. In dieser Arbeit wird untersucht, wie sich die Wahl der Kontaktbedingung aus den Alternativen Orts‐ bzw. Kraftbedingung (d.h. Kontakt wird angenommen, solange Eindringen vorliegt bzw. die Kontaktkraft eine Druckkraft ist) auf das Haftverhalten des Kontaktes auswirkt. Die Problematik wird anhand eines geradlinigen Stoßes eines Massepunktes auf ein Feder‐Dämpfer System untersucht, nachdem einführend ein einfaches kontinuumsmechanisches Modell eines axialen Stoßes eines Massepunktes auf einen Stab behandelt wird. Bei beiden Untersuchungen wird eine den Massepunkt belastende, konstante Kraft berücksichtigt, die besonders bei kleinen Stoßgeschwindigkeiten nicht mehr vernachlässigt werden darf. Für das Feder‐Dämpfer Kontaktmodell können die maßgeblichen Parameter und mit diesen die Bereiche unterschiedlichen Haftverhaltens angegeben werden. Abschließend wird gezeigt, wie die Überlegung zum einfachen geradlinigen Stoßvorgang auf Einfachstöße in der Mehrkörperdynamik nutzbringend angewandt werden kann. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Oscillations of Carbon Brushes in Hand‐held Electrical Tools
Authors: Yan Shuiping , Eiber Albrecht , Schiehlen Werner 
Published: November 2004

AbstractA series‐universal motor is usually used in hand‐held electrical tools, such as cutting or grinding machines. The corresponding two carbon brushes are preloaded by springs to maintain a proper contact necessary to reduce their wear and erosion.The oscillations of carbon brushes are coupled with the rotor motion. A model including carbon brushes and the main parts of tool rotor is described. By using the method of multibody systems the equations of motion are derived. The one‐sided contact forces and the electrical forces between commutator and brushes are mainly responsible for the nonlinear oscillations of brushes. The contour of contact surface is one of the major parameters of contact force.There exist periods where the brushes are separated from the commutator, i.e. a free flight motion of carbon brush occurs. The measured and simulated results show that a large spring preload and a small brush mass improve the contact and result in reduced free flight periods. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Macroscopic Modelling of Vibration and Stability Problems in Prestressed Microperiodic Elastic Solids
Authors: Woźniak Czeslaw , Woźniak Margaret 
Published: November 2004

AbstractThe aim of this contribution is to propose and apply a certain averaged (macroscopic) mathematical model for the analysis of vibration and stability problems of prestressed microperiodic elastic solids. In contrast to the known homogenized model [2], [3] the proposed model describes the effect of the period length on the macroscopic solid behaviour. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
FE Modelling of NiTi‐Composed Structures
Authors: Christ Daniel , Reese Stefanie 
Published: November 2004

AbstractThe present contribution focuses on the finite element modelling of NiTi‐based shape memory alloys. For this purpose, the concept of Helm [1] has been further developed and implemented into a finite element formulation. The model is able to describe the multiaxial behaviour of SMA and therefore useful for the simulation of complex problems. Additional emphasis is put on the modelling of the shape memory effect in composites where the interaction between the alloy and other materials like e.g. polymers plays an important role. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Berechnung von Kohlenstoffnanoröhren mit Finiten Elementen
Authors: Ernst Gerald , Nasdala Lutz , Rothert Heinrich 
Published: November 2004

AbstractKraftfeldansätze für die Berechnung atomarer Strukturen können in die Finite Elemente Methode eingebettet werden. Standard‐Elemente sind jedoch nicht in der Lage, die Atomphysik adäquat wiederzugeben. Anhand von Berechnungen von Kohlenstoffnanoröhren wird gezeigt, dass ein neues 4‐Knoten‐Element geeignet ist, atomare Strukturen zuverlässig zu berechnen. Auch Defekte in der Struktur der Kohlenstoffnanoröhren können damit berücksichtigt werden. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An Approximation for Electrically Semipermeable Edge Cracks and its Application to Fracture Analysis of PZT
Authors: Kessler H. , Balke H. , Jelitto H. , Schneider G. A. 
Published: November 2004

AbstractApproximate intensity factors are calculated in four point bending by combination of the nonlinear piezoelectric Griffith crack solution with linear finite element solutions for the impermeable and completely permeable edge crack problem. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Prenatal diagnosis of DMD in a female foetus affected by Turner syndrome
Authors: Satre V. , Monnier N. , Devillard F. , Amblard F. , Lunardi Pr J. 
Published: November 2004

AbstractObjectivesWe report on a prenatal diagnosis of DMD complicated by a 45,X karyotype that was revealed only in the chorionic villus long‐term culture.MethodsCytogenetic investigations were performed on both short‐term (STC) and long‐term cultures (LTC) of the chorionic villus sample. Familial segregation was performed using a panel of intragenic polymorphic markers, and multiplex PCR was used to characterize exonic deletion.ResultsInvestigations performed for sex determination after STC of the chorionic villus sample showed a normal karyotype 46,XX, while the karyotype performed after LTC revealed a homogeneous monosomy X. Cytogenetic analysis performed on amniotic fluid cells showed 45,X/46,XX mosaicism. Familial segregation analysis for DMD showed loss of heterozygosity for the STR49 marker in the DNA of the proband, her mother and the foetus. Dystrophin gene analysis on the 45,X cells led to the identification of a deletion of exon 50.ConclusionsThe report described a rare situation of monosomy X associated with a DMD genotype. The data confirmed the DMD carrier status of the proband and her mother and indicated that the foetus had a high risk to combine a Turner phenotype and DMD. This study illustrated the potential risk of using short‐term culture of villi as the only source of biological material for prenatal diagnosis. Copyright © 2004 John Wiley & Sons, Ltd.
Ultrasound diagnosis of fetal anomalies: an analysis of perinatal management of 318 consecutive pregnancies in a multidisciplinary setting
Authors: Bijma Hilmar H. , Schoonderwaldt Ernst M. , van der Heide Agnes , Wildschut Hajo I. J. , van der Maas Paul J. , Wladimiroff Juriy W. 
Published: November 2004

AbstractObjectivesThe objectives of this study are to analyse the perinatal management decisions made in a multidisciplinary setting following the prenatal diagnosis of fetal anomalies and to evaluate to what extent, in clinical practice, decisions about obstetric management are attuned to those about neonatal management.MethodsData on perinatal management of 318 consecutive singleton pregnancies presented to a multidisciplinary perinatal team in a tertiary centre were collected retrospectively.ResultsThe multidisciplinary perinatal team decided upon non‐aggressive obstetric management in 20% of the cases and consented to termination of pregnancy in 10% of the cases. The multidisciplinary perinatal team decided upon neonatal management in 112(36%) of all fetuses. In 100(89%) of these fetuses, standard neonatal management, and in 12(11%), no neonatal life‐sustaining treatment was decided upon. Implementation of the decisions of the multidisciplinary perinatal team on the various management modalities ranged from 88 to 100%.ConclusionThe multidisciplinary perinatal team worked well in making decisions about obstetric management. In 30% of the cases, this concerned end‐of‐life decisions. However, for the majority of cases, the perinatal team did not plan neonatal management before birth and thereby did not attune obstetric and neonatal management to each other. This probably reflects the different attitudes towards end‐of‐life decisions between obstetricians and neonatologists. However, to ensure a consistent perinatal management, a multidisciplinary perinatal team has to make prenatal decisions about both obstetric and neonatal management. Copyright © 2004 John Wiley & Sons, Ltd.
Age‐standardisation when target setting and auditing performance of Down syndrome screening programmes
Authors: Cuckle Howard , Aitken David , Goodburn Sandra , Senior Brian , Spencer Kevin , Standing Sue ,   on behalf of the UK National Down's Syndrome Screening Programme, Laboratory Advisory Group
Published: November 2004

AbstractObjectiveTo describe and illustrate a method of setting Down syndrome screening targets and auditing performance that allows for differences in the maternal age distribution.MethodsA reference population was determined from a Gaussian model of maternal age. Target detection and false‐positive rates were determined by standard statistical modelling techniques, except that the reference population rather than an observed population was used. Second‐trimester marker parameters were obtained for Down syndrome from a large meta‐analysis, and for unaffected pregnancies from the combined results of more than 600 000 screens in five centres. Audited detection and false‐positive rates were the weighted average of the rates in five broad age groups corrected for viability bias. Weights were based on the age distributions in the reference population.ResultsMaternal age was found to approximate reasonably well to a Gaussian distribution with mean 27 years and standard deviation 5.5 years. Depending on marker combination, the target detection rates were 59 to 64% and false‐positive rate 4.2 to 5.4% for a 1 in 250 term cut‐off; 65 to 68% and 6.1 to 7.3% for 1 in 270 at mid‐trimester. Among the five centres, the audited detection rate ranged from 7% below target to 10% above target, with audited false‐positive rates better than the target by 0.3 to 1.5%.ConclusionAge‐standardisation should help to improve screening quality by allowing for intrinsic differences between programmes, so that valid comparisons can be made. Copyright © 2004 John Wiley & Sons, Ltd.
Mathematical modeling and numerical simulation of cell growth in injection molding of microcellular plastics
Authors: Osorio Andres , Turng Lih‐Sheng 
Published: November 2004

AbstractA mathematical formulation and numerical simulation for non‐isothermal cell growth during the post‐filling stage of microcellular injection molding have been developed. The numerical implementation solves the energy equation, the continuity equation, and a group of equations that describe the mass diffusion of dissolved gas and growth of micro‐cells in a microcellular injection molded part. The “unit‐cell” model employed in this study takes into account the effects of injection and packing pressures, melt and mold temperatures, and super‐critical fluid content on the material properties of the polymer‐gas solution and the cell growth. The material system studied is a microcellular injection molded polyamide 6 (PA‐6) resin. Two Arrhenius‐type equations are used to estimate the coefficients of mass diffusion and solubility for the polymer‐gas solution as functions of temperature. The dependence of the surface tension on the temperature is also included in this study. The numerical results in terms of cell size across the sprue diameter agree fairly well with the experimental observation. The predicted pressure profile at the sprue location has also been found to be in good agreement with the dynamics of the cell growth. Whereas for conventional injection molding the pressure of the system tends to decay monotonously, the pressure profile in microcellular injection molding exhibits an initial decay resulting from cooling and the absence of packing followed by an increase due to cell growth that expands the polymer‐gas solution and helps to pack out the mold uniformly. Polym. Eng. Sci. 44:2274–2287, 2004. © 2004 Society of Plastics Engineers.
Electron ionization mass spectrometric study of 1,4‐dihydro‐4‐substituted 2,6‐dimethyl‐3,5‐bis(alkoxycarbonyl)pyridines
Authors: Salehi Hojatollah , Li Qianrong , Yin Hao , Ding Yi , Guo Qingxiang 
Published: November 2004

AbstractUsing the accurate masses obtained from a time‐of‐flight instrument and the tandem mass spectrometric (MS/MS) data from an ion trap instrument, electron ionization mass spectra of a series of 1,4‐dihydro‐4‐substituted 2,6‐dimethyl‐3,5‐bis(alkoxycarbonyl)pyridines are reported and rationalized. Two sets of fragmentation pathways are proposed. One involves the formation of fragment ions containing the 1,4‐dihydropyridine structure, and the other of ions containing a pyridine ring. Copyright © 2004 John Wiley & Sons, Ltd.
Coupling of fully automated chip electrospray to Fourier transform ion cyclotron resonance mass spectrometry for high‐performance glycoscreening and sequencing
Authors: Froesch Martin , Bindila Laura M. , Baykut Gökhan , Allen Mark , Peter‐Katalinić Jasna , Zamfir Alina D. 
Published: November 2004

AbstractThe NanoMate robot has been coupled to a Fourier transform ion cyclotron resonance (FTICR) mass spectrometer at 9.4 T and implemented for the first time for complex carbohydrate analysis. It was optimized in the negative ion mode to achieve automated sample delivery on the chip along with increased sensitivity, ultra‐high resolution and accurate mass determination. A novel bracket has been designed to allow a reliable mounting of the NanoMate to the Apollo electrospray ionization (ESI) source of an APEX II instrument. The notably higher efficiency of ionization for compositional mapping of complex mixtures and feasibility for fragmentation analysis of components by sustained off‐resonance irradiation collision‐induced tandem mass spectrometry (SORI‐CID MS2) has been demonstrated on a glycoconjugate mixture containing O‐glycosylated sialylated peptides from urine of a patient suffering from a hereditary N‐acetylhexosaminidase deficiency (Schindler's disease), previously analyzed by capillary‐based nanoESI‐FTICRMS, and of a healthy control person. Due to its potential to generate highly charged ionic species, reduce the in‐source fragmentation, increase sensitivity, reproducibility and ionization efficiency, along with the ability to generate a sustained and constant electrospray, this method can be considered as a new platform for advanced glycomics. Copyright © 2004 John Wiley & Sons, Ltd.
Characterization of limonin glucoside metabolites from human prostate cell culture medium using high‐performance liquid chromatography/electrospray ionization mass spectrometry and tandem mass spectrometry
Authors: Tian Qingguo , Kent Kyle D. , Bomser Joshua A. , Schwartz Steven J. 
Published: November 2004

AbstractThe metabolism of limonin 17‐β‐D‐glucopyranoside (LG) by non‐cancerous (RWPE‐1) and cancerous (PC‐3) human prostate epithelial cells was investigated using high‐performance liquid chromatography/electrospray ionization mass spectrometry (LC/ESI‐MS) with in‐source fragmentation and tandem mass spectrometry (MS/MS). During positive ion LC/ESI‐MS, LG formed an abundant sodiated species ([M+Na]+) while the protonated molecule was barely observable. [M+Na]+ further fragmented into the less abundant [LARL+H]+ and a predominantly protonated aglycone molecule (limonin) due to in‐source fragmentation. The major metabolite, limonin A‐ring lactone (LARL), formed an abundant protonated molecule that was fragmented into a protonated molecule of limonin by loss of one molecule of water. In MS/MS by collisionally activated dissociation (CAD), LG produced the sodiated aglycone, [aglycone+Na]+, while LARL fragmented into [M+H]+ of limonin and fragment ions resulted by further loss of water, carbon monoxide and carbon dioxide, indicating the presence of oxygenated‐ring structures. The limits of detection of LG were 0.4 and 20 fmol in selected‐ion monitoring (SIM) and selected‐reaction monitoring (SRM) detection, respectively. Copyright © 2004 John Wiley & Sons, Ltd.
GUD1 (YDL238c) encodes Saccharomyces cerevisiae guanine deaminase, an enzyme expressed during post‐diauxic growth
Authors: Saint‐Marc Christelle , Daignan‐Fornier Bertrand 
Published: November 2004

AbstractPurine salvage is a complex pathway allowing a correct balance between adenylic and guanylic derivatives. In this paper, we show that GUD1 (YDL238c) encodes guanine deaminase, a catabolic enzyme producing xanthine and ammonia from guanine. Importantly, Gud1p activity was higher during post‐diauxic growth, suggesting that a decrease of the guanylic nucleotide pool could be required when cells shift from proliferation to quiescence. Copyright © 2004 John Wiley & Sons, Ltd.
Health status and mortality in Holocaust survivors living in Jerusalem 40–50 years later
Authors: Collins Chen , Burazeri Genc , Gofin Jaime , Kark Jeremy D. 
Published: November 2004

AbstractThe long‐term health sequelae of the Holocaust were assessed 40–50 years later in the framework of a Jerusalem community health study. Holocaust survivors (N = 288, mean age = 67.6 years) and European‐born Jews, not exposed to the Holocaust (N = 486, mean age = 68.9 years), were studied in 1985–87. Our objective was to compare psychobehavioral factors, clinical variables, and mortality outcomes. The comparisons revealed higher emotional distress scores in female Holocaust survivors than in unexposed women and poorer self‐appraised health status in male Holocaust survivors than unexposed men. A 10‐year mortality follow‐up that terminated in April 1996 showed no significant association with Holocaust exposure. Long‐term Holocaust survivors may represent a selective resilient group.
Vocational function among persons with schizophrenia with and without history of childhood sexual trauma
Authors: Lysaker Paul H. , Nees Michael A. , Lancaster Rebecca S. , Davis Louanne W. 
Published: November 2004

AbstractThis study examined whether history of childhood sexual abuse in schizophrenia is linked with severity of vocational deficits. Work performance was measured using the Work Behavior Inventory and hours of work performed in a vocational rehabilitation program and then compared for 12 participants with schizophrenia or schizoaffective disorder reporting abuse and 18 with schizophrenia with no abuse history. ANOVAs indicated that the sexual abuse group worked fewer hours during the first 4 weeks of the program and demonstrated poorer work performance overall. An interaction was found suggesting that the sexually abused group's performance declined as the nonsexually abused group improved overtime. Childhood sexual abuse may be associated with greater vocational deficits in adults with schizophrenia.
Structural studies of duck δ2 crystallin mutants provide insight into the role of Thr161 and the 280s loop in catalysis
Authors: SAMPALEANU Liliana M. , CODDING Penelope W. , LOBSANOV Yuri D. , TSAI May , SMITH G. David , HORVATIN Cathy , HOWELL P. Lynne 
Published: November 2004

δ Crystallin, a taxon-specific crystallin present in avian eye lenses, is homologous to the urea cycle enzyme ASL (argininosuccinate lyase). Although there are two δ crystallin isoforms in duck lenses, dδc1 (duck δ1 crystallin) and dδc2 (duck δ2 crystallin), only dδc2 is catalytically active. Previous structural studies have suggested that residues Ser283 and His162 in the multi-subunit active site of dδc2/ASL are the putative catalytic acid/base, while the highly conserved, positively charged Lys289 is thought to help stabilize the carbanion intermediate. The strict conservation of a small hydroxy-containing residue (Thr or Ser) at position 161 adjacent to the putative catalytic base, as well as its proximity to the substrate in the S283A dδc2 enzyme–substrate complex, prompted us to investigate further the role this residue. Structures of the active T161S and inactive T161D dδc2 mutants, as well as T161D complexed with argininosuccinate, have been determined to 2.0 Å resolution. The structures suggest that a hydroxy group is required at position 161 to help correctly position the side chain of Lys289 and the fumarate moiety of the substrate. Threonine is probably favoured over serine, because the interaction of its methyl group with Leu206 would restrict its conformational flexibility. Residues larger than Thr or Ser interfere with substrate binding, supporting previous suggestions that correct positioning of the substrate's fumarate moiety is essential for catalysis to occur. The presence of the 280s loop (i.e. a loop formed by residues 270–290) in the ‘open’ conformation suggests that loop closure, thought to be essential for sequestration of the substrate, may be triggered by the formation of the carbanion or aci-carboxylate intermediates, whose charge distribution more closely mimics that of the sulphate ion found in the active-site region of the inactive dδc1. The 280s loop in dδc1 is in the closed conformation.