bluuebunny/crossref_metadata_2025_split huggingface dataset:
Eindimensionale, stationäre Verdichtungsströmungen in einem Gas mit Relaxation
Authors: Becker E. 
Published: May 2007

AbstractEs wird die eindimensionale, stationäre Strömung eines Gases betrachtet, in dem thermodynamische Relaxationsvorgänge ablaufen. Unter verhältnismäßig allgemeinen Voraussetzungen über das thermodynamische Verhalten des Gases sowie über den Ablauf der Relaxationsvorgänge wird zunächst für den Fall eines einzigen Relaxationsvorganges gezeigt, daß folgende, für Spezialfälle schon länger bekannte Situation besteht: In einem gewissen Bereich von Anströmgeschwindigkeiten existiert eine eindeutig bestimmte, stetige „volldispergierte”︁ Welle, oberhalb dieses Bereiches ein unstetiger „gefrorener”︁ Verdichtungsstoß mit nachfolgender, stetiger Relaxationszone („unvollständig dispergierte”︁ Welle). Anschließend wird gezeigt, unter welchen zusätzlichen Voraussetzungen und auf welche Weise sich diese Ergebnisse auf den Fall mehrerer Relaxationsvorgänge erweitern lassen. Hierbei wird speziell die Strömung mit zwei Relaxationsfreiheitsgraden studiert. Allgemeingültige Formeln für den Verlauf der Geschwindigkeit und der Zustandsgrößen werden angegeben, die sich in Spezialfällen auf schon bekannte Formeln zurückführen lassen.
Analysis of Flood Propagation through Channels and Reservoirs: Implicit Finite Difference Method
Authors: Desikan Varadarajan 
Published: May 2007

AbstractThe problem of analyzing floods through channels and reservoir‐channel systems is important in forecasting floods and in testing the effectiveness of flood control measures. The problem has been solved, numerically, by the finite difference method using a digital computer. The direct (explicit) difference scheme necessitates very small time intervals for convergence, and consequently results in lengthy computations which become prohibitive even on a fast computer. The present paper developes, on the other hand, an implicit finite difference scheme, which is unconditionally convergent, so that any time interval, however large, can be used. The method can be used with advantage on the electronic computer as well as on the desk calculator. When applied to a practical problem of flood propagation, the digital computer time was reduced from thirty five hours, as required by the explicit method, to half an hour by the present method.
On the Uniqueness and Transformation of the Coleman‐Noll Approximation Theorem for Functionals
Authors: Leigh D. C. 
Published: May 2007

AbstractIt is shown that if a change of the argument function is made in a functional the value of the n‐th order Coleman‐Noll approximation is unaltered. The result means, for example, that any suitably invariant measure of strain may be used in developing an approximation to a functional constitutive equation in continuum mechanics. Also, the transformation of an approximation from one strain measure to another is developed.
Parameterresonanz in fastkanonischen Systemen
Authors: Starshinski W. M. , Beyreuther J. 
Published: May 2007

AbstractNach einer Methode von Jakubowitsch findet man Ungleichungen zur Bestimmung von Bereichen kinetischer Instabilität für ein lineares Differentialgleichungssystem mit (komplexen) periodischen Koeffizienten, die analytisch von einem kleinen Parameter ε abhängen. Für ε = 0 soll das Ausgangssystem in ein kanonisches System mit konstanten Koeffizienten übergehen. Als Anwendungsbeispiel werden Biegeschwingungen zweier koaxialer Wellen mit Schwungscheiben am Ende bei konstanten Drehzahlen untersucht.
Symmetrische Koppelkurven mit zwei Flachpunkten
Authors: Tesar D. , Wunderlich W. 
Published: May 2007

AbstractDie Konstruktion von Gelenkvierecken, welche symmetrische Koppelkurven, mit zwei Flachpunkten erzeugen, wird auf ein kubisches Problem zurückgeführt und sowohl graphisch als auch rechnerisch gelöst. Gewisse Sonderfälle gestatten eine vereinfachte Behandlung.
Das d'Alembertsche Anfangswertproblem für Zylinderwellen
Authors: Heynatz J. T. 
Published: May 2007

AbstractFür Zylinderwellen kleiner Amplitude wird eine Darstellung des d' Alembertschen Anfangswertproblems gegeben. Auf dem Wege über die Lösung zweier Abelscher Integralgleichungen und anschließender Integralvertauschungen gelangt man durch die Rückführung der auftretenden elliptischen Integrale auf vollständige Legendresche Normalformen zu einer dem ebenen und dem kugelsymmetrischen Fall entsprechenden Darstellung der linearisierten Potentialgleichung. Während man sich sonst häufig mit der Ausbreitung von Zylinderwellen beschäftigt, die durch eine auf der Zylinderachse als Funktion der Zeit gegebene Quelltätigkeit verursacht werden, handelt es sich hier um die Bestimmung von Strömungsfeldern aus Anfangswerten, die zu einer festen Zeit als Funktionen des Zylinderradius gegeben sind. Die Resultate dienen zur Berechnung der durch einen Drucksprung verursachten Strömung. Der Geschwindigkeitsverlauf und die Druckverteilung entsprechen qualitativ dem kugelsymmetrischen Fall. Es handelt sich um einfache Funktionen von elliptischen Normalintegralen erster, zweiter und dritter Gattung. Für die Abgeschlossenheit von Zylinderwellen unter verschiedenen Voraussetzungen werden Bedingungen aufgestellt.
Linearisierung des schwerebehafteten Gleitproblems
Authors: Stumpf H. 
Published: May 2007

AbstractEs werden die Zusammenhänge zwischen Bodenform, Druckverteilung und Widerstand einer stationär über die ungestörte Wasseroberfläche bewegten Gleitfläche untersucht, wobei eine Trennung des Geschwindigkeitspotentials in einen von der Erdschwere unabhängigen sowie in einen von der Erdschwere abhängigen Anteil durchgeführt wird. Das schwerefreie Geschwindigkeitspotential, das den Gleitvorgang für unendlich große Froudesche Zahl beschreibt und das alle wesentlichen Irregularitäten des Gleitproblems beinhaltet, liefert die schwerefreie Form der Gleitfläche sowie Spritz‐ und induzierten Widerstand. Der den Schwereeinfluß darstellende Potentialanteil gestattet eine Berechnung der Änderung. die die Form der Druckfläche infolge Wirkung der Erdschwere erfährt und die für breite Gleitflächen und große Froudesche Zahl linearisiert werden kann. Hiermit ergibt sich für das schwerebehaftete Gleiten eine einfache Beziehung zwischen Druckverteilung und Bodenform, wobei man als dritte Widerstandskomponente einen der Erdschwere proportionalen Widerstand erhält.
Abwindkorrekturen für kreisrunde Windkanäle mit Bodenplatte
Authors: Pfeiffer F. 
Published: May 2007

AbstractFür offene und geschlossene Windkanäle mit Bodenplatte wird ein Verfahren entwickelt, das den Einfluß der endlichen Strahlabmessungen auf die gemessenen aerodynamischen Beiwerte eines Tragflügels mit beliebiger Pfeilung, Streckung und Zuspitzung sowie beliebigem Bodenabstand zu berechnen gestattet.
Endliche elastische Verformungen
Authors: Vocke W. 
Published: May 2007

AbstractZur Beschreibung von elastischen Verformungen bis zu Werten von etwa 15% bringt die Berücksichtigung der quadratischen Glieder eine sehr gute Näherung. Es wird dabei das in diesem Bereich für viele Stoffe gültige lineare Realspannungs‐Dehnungs‐Gesetz verwendet.
Asymptotisches Verhalten der Lösungen der modizifierten van der Polschen Differentialgleichung
Authors: Maess G. 
Published: May 2007

AbstractDie modifizierte van der Polsche Differentialgleichung (1) läßt sich durch die Transformation x2 sgn x = v in eine stückweise lineare Differentialgleichung überführen. Für deren allgemeine Lösung (6) wird die asymptotische Darstellung (μ → ∞) berechnet und daraus die asymptotische Entwicklung der Amplitude a der periodischen Lösung von (1) bestimmt.
Significance of CD44 Expression in Gastrointestinal Stromal Tumors in Relation to Disease Progression and Survival
Authors: Hsu Kai‐Hsi , Tsai Hung‐Wen , Shan Yan‐Shen , Lin Pin‐Wen 
Published: May 2007

AbstractBackgroundCD44 is a transmembrane glycoprotein belonging to the cell‐adhesion molecule family. It has been identified as being involved in tumor progression and metastasis, and its expression has been found to be of prognostic significance in several human malignancies. The aim of this study was to assess CD44 expression in gastrointestinal stromal tumors (GISTs), the most common mesenchymal tumor of the gastrointestinal tract.MethodsBetween January 1995 and March 2006, 92 patients undergoing surgical resection for GIST in National Cheng Kung University Hospital were evaluated. To study the significance of CD44 expression, immunohistochemical staining of CD44 in tumor specimens was performed, and the clinicopathological information of patients was reviewed.ResultsFifty‐nine of 81 patients (73%) showed positive CD44 expression. Loss of CD44 expression was associated with disease progression (p = 0.019). Kaplan‐Meier analysis revealed better progression‐free survival among patients with strong CD44 expression (++ and +++) (p = 0.034), absence of disease progression (p < 0.001), and lower risk, according to National Institutes of Health (NIH) Consensus Criteria for GIST risk stratification (p = 0.003). Multivariate analysis demonstrated that high‐risk status was the only independent risk factor for disease progression and the only independent predictor for a poor progression‐free survival (p = 0.023 and 0.045, respectively).ConclusionsIt is demonstrated that high‐risk status by NIH criteria is significantly associated with disease progression and poor progression‐free survival in GIST.
Humangenetische Beratung
Authors: Zerres K. , Grimm T. , Rudnik-Schöneborn S. 
Published: May 2007

Zusammenfassung
Mit den wachsenden Möglichkeiten der genetischen Diagnostik gewinnt die humangenetische Beratung in der klinischen Medizin an Bedeutung. Sie soll Ratsuchenden helfen, Fragen im Zusammenhang mit einer evtl. erblich bedingten Krankheit oder Entwicklungsstörung zu beantworten und mögliche Probleme zu lösen. Wichtige Anlässe einer solchen Beratung sind u. a. eine Erkrankung oder Entwicklungsstörung eines Kindes, eines Ratsuchenden oder Verwandten, so genannte altersbedingte Risiken, eine Blutsverwandtschaft, habituelle Aborte, Totgeburten, Fertilitätsstörungen sowie die Sorge vor möglichen teratogenen oder mutagenen Risiken. Ergebnisse der pränatalen, der prädiktiven sowie der Heterozygotendiagnostik können eine Tragweite besitzen, die sich von der Diagnostik im Rahmen der Abklärung einer klinischen Symptomatik unterscheidet. Die Entscheidung hierzu sollte nach einer vorangegangen humangenetischen Beratung „informiert“ erfolgen. Der Beitrag informiert über die Ziele, die Durchführung und mögliche Anlässe einer humangenetischen Beratung.
BLOCKS WITH A QUATERNION DEFECT GROUP OVER A 2-ADIC RING: THE CASEÃ4
Authors: HOLM THORSTEN , KESSAR RADHA , LINCKELMANN MARKUS 
Published: May 2007

Abstract.Except for blocks with a cyclic or Klein four defect group, it is not known in general whether the Morita equivalence class of a block algebra over a field of prime characteristic determines that of the corresponding block algebra over ap-adic ring. We prove this to be the case when the defect group is quaternion of order 8 and the block algebra over an algebraically closed fieldkof characteristic 2 is Morita equivalent tokÃ4. The main ingredients are Erdmann's classification of tame blocks [6] and work of Cabanes and Picaronny [4, 5] on perfect isometries between tame blocks.
ON BRANNAN'S COEFFICIENT CONJECTURE AND APPLICATIONS
Authors: RUSCHEWEYH STEPHAN , SALINAS LUIS 
Published: May 2007

Abstract.D. Brannan's conjecture says that for 0 <α,β≤1, |x|=1, and n∈N one has |A2n−1(α,β,x)|≤|A2n−1(α,β,1)|, where

We prove this for the case α=β, and also prove a differentiated version of the Brannan conjecture. This has applications to estimates for Gegenbauer polynomials and also to coefficient estimates for univalent functions in the unit disk that are ‘starlike with respect to a boundary point’. The latter application has previously been conjectured by H. Silverman and E. Silvia. The proofs make use of various properties of the Gauss hypergeometric function.
COMMON SOURCE OF NUMEROUS THETA FUNCTION IDENTITIES
Authors: WENCHANG CHU 
Published: May 2007

Abstract.Motivated by the recent work due to Warnaar (2005), two new and elementary proofs are presented for a very useful q-difference equation on eight shifted factorials of infinite order. As the common source of theta function identities, this q-difference equation is systematically explored to review old and establish new identities on Ramanujan's partition functions. Most of the identities obtained can be interpreted in terms of theorems on classical partitions.
LINEAR ASYMPTOTIC BEHAVIOUR OF SECOND ORDER ORDINARY DIFFERENTIAL EQUATIONS
Authors: EHRNSTRÖM MATS 
Published: May 2007

Abstract.We study the semilinear differential equation u″ + F(t,u,u′)=0 on a half-line. Under different growth conditions on the function F, equations with globally defined solutions asymptotic to lines are characterized. Both fixed initial data and fixed asymptote are considered.
URSCM OR BI-URSCM FOR p-ADIC ANALYTIC OR MEROMORPHIC FUNCTIONS INSIDE A DISK
Authors: BOUTABAA ABDELBAKI , ESCASSUT ALAIN 
Published: May 2007

Abstract.Let K be an algebraically closed field of characteristic zero, complete with respect to an ultrametric absolute value. In a previous paper, we had found URSCM of 7 points for the whole set of unbounded analytic functions inside an open disk. Here we show the existence of URSCM of 5 points for the same set of functions. We notice a characterization of BI-URSCM of 4 points (and infinity) for meromorphic functions in K and can find BI-URSCM for unbounded meromorphic functions with 9 points (and infinity). The method is based on the p-Adic Nevanlinna Second Main Theorem on 3 Small Functions applied to unbounded analytic and meromorphic functions inside an open disk and we show a more general result based upon the hypothesis of a finite symmetric difference on sets of zeros, counting multiplicities.
A wave propagation model of blood flow in large vessels using an approximate velocity profile function
Authors: BESSEMS DAVID , RUTTEN MARCEL , VAN DE VOSSE FRANS 
Published: May 2007

Lumped-parameter models (zero-dimensional) and wave-propagation models (one-dimensional) for pressure and flow in large vessels, as well as fully three-dimensional fluid–structure interaction models for pressure and velocity, can contribute valuably to answering physiological and patho-physiological questions that arise in the diagnostics and treatment of cardiovascular diseases. Lumped-parameter models are of importance mainly for the modelling of the complete cardiovascular system but provide little detail on local pressure and flow wave phenomena. Fully three-dimensional fluid–structure interaction models consume a large amount of computer time and must be provided with suitable boundary conditions that are often not known. One-dimensional wave-propagation models in the frequency and time domain are well suited to obtaining clinically relevant information on local pressure and flow waves travelling through the arterial system. They can also be used to provide boundary conditions for fully three-dimensional models, provided that they are defined in, or transferred to, the time domain.Most of the one-dimensional wave propagation models in the time domain described in the literature assume velocity profiles and therefore frictional forces to be in phase with the flow, whereas from exact solutions in the frequency domain a phase difference between the flow and the wall shear stress is known to exist. In this study an approximate velocity profile function more suitable for one-dimensional wave propagation is introduced and evaluated. It will be shown that this profile function provides first-order approximations for the wall shear stress and the nonlinear term in the momentum equation, as a function of local flow and pressure gradient in the time domain. The convective term as well as the approximate friction term are compared to their counterparts obtained from Womersley profiles and show good agreement in the complete range of the Womersley parameter α. In the limiting cases, for Womersley parameters α → 0 and α → ∞, they completely coincide. It is shown that in one-dimensional wave propagation, the friction term based on the newly introduced approximate profile function is important when considering pressure and flow wave propagation in intermediate-sized vessels.
Mycocalicium llimonae, a new species from the Iberian Peninsula
Authors: MUÑIZ Diana , HLADUN Néstor L. 
Published: May 2007

Abstract:The new species, Mycocalicium llimonae, is described based on specimens collected from cones of Pinus halepensis in the west of the Iberian Peninsula. The new taxon is compared with the other species of the genus Mycocalicium in the Iberian Peninsula, particularly Mycocalicium subtile, and also with other genera in the Mycocaliciaceae.
Corticifraga santessonii and C. chugachiana (Lecanoromycetes, Ascomycota), new species of lichenicolous fungi from the Holarctic
Authors: ZHURBENKO Mikhail 
Published: May 2007

Abstract:Two new lichenicolous ascomycetes, Corticifraga santessonii and C. chugachiana, are described from Lobaria and Nephroma species. The new species are readily distinguished by narrow ascospores and are known from the USA, Canada and Russia. A Table with the distinguishing characteristics of all known Corticifraga species is presented.
A new species of Graphis (Graphidaceae) from India
Authors: JAGADEESH RAM T. A. M. , SINHA G. P. , SINGH K. P. 
Published: May 2007

Abstract:A new species of lichen, Graphis sundarbanensis, is described from India. It is characterized by ascomata with a pruinose wide-open disc, a laterally carbonized apically convergent exciple and 6–8 locular halonate ascospores.
New or interesting saxicolous Pertusaria species (Pertusariales: Pertusariaceae) from Zimbabwe
Authors: MESSUTI María Inés , BECKER Uwe , ARCHER Alan W. 
Published: May 2007

Abstract:%The new saxicolous species P. clercii Messuti & A. W. Archer is described. The following two taxa are reported for the first time from Africa: P. petrophyes C. Knight and P. subventosa var. deficiens A. W. Archer & Elix. A brief description of each species is given together with notes on their chemistry, distribution, ecology and taxonomy.
Predicting the potential spatial distributions of epiphytic lichen species at the landscape scale
Authors: BOLLIGER Janine , BERGAMINI Ariel , STOFER Silvia , KIENAST Felix , SCHEIDEGGER Christoph 
Published: May 2007

Abstract:The potential spatial distributions of six epiphytic lichen species were assessed in Switzerland (41 000 km2) as a function of various key climatic drivers and forest types using logistic regression models. Cetrelia cetrarioides is ‘near threatened’, Lobaria pulmonaria is ‘vulnerable’, and Graphis scripta, Hypogymnia physodes, Lecanora cadubriae, Letharia vulpina are not endangered according to the Red List assessment based on IUCN criteria. Lichen presence and absence were derived from the SwissLichens database that contains spatially explicit information on both species presence and absence.The spatial lichen niches are predicted with R2 values between 0·5 and 0·75 and AUC values between 0·63 and 0·94. Model evaluation shows that the models perform well.Lichenologists reviewed the spatial predictions of lichen species on the basis of their expert knowledge and concluded that parsimonious regression models may suffice for successful prediction of the potential spatial niche distributions of epiphytic lichen species.
Content of secondary compounds depends on thallus size in the foliose lichen Lobaria pulmonaria
Authors: ASPLUND Johan , GAUSLAA Yngvar 
Published: May 2007

Abstract:Thalli of Lobaria pulmonaria of different sizes were collected from the trunks of two specimens of Populus tremula. The secondary lichen compounds, stictic, constictic, norstictic, peristictic, cryptostictic and methyl stictic acid were quantified by HPLC and ranked in order of decreasing concentration. There was a highly significant positive correlation between thallus size and the total concentration of secondary compounds, as well as the total content per unit area for specimens from the two sampled trees. According to hypotheses inferring a herbivore deterrent role of secondary lichen compounds, small, juvenile thalli should be more susceptible to herbivores than larger thalli. Thus herbivory might limit survival of young specimens in habitats rich in lichen-feeding molluscs and thereby reduce reproductive success.
Bacidia coprodes—resurrecting a misinterpreted species
Authors: LLOP Esteve , EKMAN Stefan 
Published: May 2007

Abstract:Bacidia coprodes (Körb.) Lettau, until now treated as a synonym of Bacidia trachona (Ach.) Lettau, is resurrected. Morphological, chemical and ecological characteristics place this species close to Toninia in the Ramalinaceae, but we retain it in Bacidia because of uncertainties in the generic taxonomy of this family. Bacidia coprodes is fairly widespread on calcareous and enriched siliceous rock in Europe and eastern North America. In North America the species has also been known under the synonyms Bacidia granosa (Tuck.) Zahlbr. (basionym: Lecidea granosa Tuck.) and Bacidia pammellii (Fink) Zahlbr. (basionym: Bilimbia pammellii Fink). Morphological and chemical features, together with molecular data, suggest that B. trachona does not belong to Bacidia, but rather in the Pilocarpaceae.
New evidence corroborates population differentiation in Xanthoria parietina
Authors: LINDBLOM Louise , EKMAN Stefan 
Published: May 2007

Abstract:In order to examine genetic variation and population structure of the widespread lichen-forming ascomycete Xanthoria parietina from similar habitats, but different sites in Scandinavia, we investigated seven populations in Scania, southernmost Sweden, and compared the results with a corresponding study on Storfosna, central Norway. Sequence variations of the nuclear ribosomal DNA were used as molecular markers, for both a part of the IGS region and the complete ITS1-5.8S-ITS2 region. The amount of genetic variability observed was comparable in the two investigations. Divergence between populations in different habitats found in the previous study was also present in this study. Xanthoria parietina is genetically differentiated between habitats with no evidence of restricted gene flow between populations in the same habitat at the present spatial scale, at least at sites along the coast of Scandinavia. Differentiation between habitats is considerable at both study sites, which we attribute to restricted gene flow between habitats, i.e. habitat isolation.
Theoretical modeling of convection II. Reynolds Stress Model
Authors: Canuto V. M. 
Published: May 2007

AbstractThe Reynolds Stress Model (RSM) yields the dynamic equations for the second-order moments (e.g., heat fluxes) needed in the equations for the mean variables (e.g., mean temperature). The RSM equations are in general time dependent and non-local. We first discuss the “buoyancy only” case and the tests of the non-local model against a variety of data. We also “plumenize” the model in order to exhibit the up-down flows that characterize convection so as to show that a non-local RSM is fully equipped to account for the “plume aspect” of buoyant flows. Next, we extend the RSM to account for stable and/or unstable stratification and shear, a formalism that is needed to describe the overshooting region contributed by differentail rotation. We conclude by discussing the equation for the dissipation of turbulent kinetic energy which plays a key role in any RSM.