bluuebunny/crossref_metadata_2025_split huggingface dataset:
Eine Bemerkung zum Zieglerschen Dissipationsprinzip in der nichtlinearen Viskoelastizitätstheorie
Authors: Balke H. 
Published: June 2007

AbstractDie Folgerungen aus dem Zieglerschen Dissipationsprinzip für spezielle nichtlinear‐viskoelastische Deformationsgesetze, die bereits zur Approximation realen Materialverhaltens benutzt wurden, werden untersucht. Die betrachteten Beispiele zeigen, daß das Dissipationsprinzip nicht hilft, brauchbare von unbrauchbaren Materialannahmen zu trennen. Es ist deshalb für diese Deformationsgesetze und ihre eventuelle Verbesserung bedeutungslos.
Similarity Solutions for Magnetogasdynamic Outflows and Inflows with Viscous, Ohmic, and Thermal Dissipation between Inclined Walls
Authors: Liron N. , Wilhelm H. E. 
Published: June 2007

AbstractNumerical solutions are presented for outflows and inflows of a compressible, ionized gas between plane inclined walls, considering Lorentz forces due to an azimuthal magnetic field, viscous momentum transfer, thermal, ohmic, and viscous energy dissipation. The analysis is based on a similarity transformation of the flow fields which reduces the (nonlinear) partial differential equations of magnetogasdynamics into ordinary ones. In addition to regular, monotone outflow and inflow solutions, “oscillatory” outflow and “mixed” outflow and inflow solutions are shown to exist in steady state for certain values of the Reynolds, Prandtl, Mach, and Hartmann numbers. Mathematical theorems are established which define the conditions for the occurrence of these flow types.
Langsame Druckströmung nicht‐NEWTONScher Flüssigkeiten durch gekrümmte Rohre
Authors: Böhme G. 
Published: June 2007

AbstractEs wird die voll ausgebildete laminare Strömung eines inkompressiblen, nicht‐newtonschen, Fluids durch ein beliebig stark gekrümmtes Rohr mit beliebigem Querschnitt untersucht. Der treibende axiale Druckgradient wird als so klein vorausgesetzt, daß das Fluid „langsam”︁ strömt. Unter solchen Bedingungen kann das allgemeine Stoffgesetz der betrachteten Flüssigkeit durch dasjenige einer Flüssigkeit zweiten Grades approximiert werden. Die Analysis beruht darauf, das Strömungsfeld in einen primären und einen sekundären Anteil aufzuspalten. Die Primärströmung ist viskosimetrisch und beschreibt die schleichende Bewegung eines newtonschen Fluids mit gleicher Nullviskosität wie die reale Flüssigkeit. Die Sekundärströmung wird durch die von der Primärströmung hervorgerufenen Zentrifugalkräfte und Normalspannungen angetrieben. Sie besteht aus mehreren Ringwirbeln in der Querschnittsebene des Rohres. Das Berechnungsverfahren führt auf lineare Randwertprobleme für das primäre und das sekundäre Geschwindigkeitsfeld, die für Rohre mit Kreisquerschnitt und Rohre mit schmalem ringförmigem Querschnitt veränderlicher Breite explizit gelöst werden.
Simple Shear of Hypo‐Elastic Materials with Internal Variables
Authors: Tokuoka T. 
Published: June 2007

AbstractThe simple shear deformations of two special hypo‐elastic materials with internal variables are analyzed. Two bodies are treated; one is the P‐R body, which has a scalar internal variable and is subjected to the modified Huber‐Mises yield criterion, and the other is the T body, which has a tensor internal variable and is subjected to the modified Tresca yield criterion. The general formulae are obtained, where the stress, time and the angle of shear are given by functions of internal variables. Numerical calculations for several values of material constants are done, and the results are illustrated, which disclose that the two bodies show work‐hardening phenomenon.
Zur Bilanz der Turbulenzenergie und ihrer Komponenten im ablösungsnahen Bereich einer turbulenten Grenzschicht
Authors: Szablewski W. 
Published: June 2007

AbstractAuf der Grundlage der kürzlich in [1] entwickelten Ansätze ergibt sich für die wandnahe vollturbulente Schicht in einem ablösungsnahen Bereich einer turbulenten Grenzschicht ein 1/3 Potenzgesetz der Turbulenzenergie und ihrer Komponenten in übereinstimmung mit Messungen von G. B. Schubauer und P. S. Klebanoff. Die Energiebilanz weist die charakteristischen Merkmale auf, die Messungen von P. Bradshaw zeigen.
On the Existence Theorem of an Eigenvalue Problem Arising from Hydrodynamics
Authors: Wen Shih‐Liang 
Published: June 2007

AbstractThe existence of a denumerable set of eigenvalues and eigenfunctions is proved for the problem: g′ + (λ2 ‐ λv‐1u) g = 0, h′ + λ2h = ‐g with h(0) = h′(0) = h(1) = h′(1) = 0. The procedure involves a suitable transformation, asymptotic expansions and complex variable techniques.
Zur zweiten und dritten Randwertaufgabe in der nichtlinearen Hyperelastizitätstheorie
Authors: Beckert Herbert 
Published: June 2007

AbstractIn der vorliegenden Arbeit wird die in einer früheren Untersuchung des Verfassers [2] entwickelte konstruktive Methode zur strengen Beschreibung endlicher Deformationen in der nichtlinearen Elastizitätstheorie von der ersten auf die zweite und dritte Randwertaufgabe übertragen. Zunächst wird die Deformation approximative über ein Differenzenverfahren entlang des Datenweges beschrieben und anschließend die Konvergenz bewiesen. Da im Falle der zweiten Randwertaufgabe der entspannte Zustand einem Randpunkt des Stabilitätsbereichs im Funktionalraum der Spannungskomponenten entspricht, wird eine H1,2 ⊖ V6‐Theorie entwickelt, um gegebenenfalls die Deformation zu stabilisieren. Die Methode läßt sich auf sehr allgemeine Strukturen der Hyperelastizitätstheorie ausdehnen.
Der Einfluß der Gas‐Teilchen‐Wechselwirkung auf den Turbulenzgrad einer turbulenten Zwei‐Phasen‐Strömung
Authors: Petrak D. 
Published: June 2007

AbstractFür eine turbulente Gasströmung wird nach Abramovich ein Modell entwickelt, mit dem die turbulenzdämpfende Eigenschaft einer Feststoffzugabe untersucht werden kann. Parameter sind hierbei die Frequenz der turbulenten Gasschwankungen, die Feststoffpartikelgröße und die Feststoffkonzentration. Für die Turbulenzdämpfung sind hauptsächlich Partikelgröße und Partikelkonzentration bestimmend.
Existenz‐ und Konvergenzsätze für die Prandtlschen Grenzschicht‐differentialgleichungen unter Benutzung der Linienmethode
Authors: Lemmert R. 
Published: June 2007

AbstractEs werden die Prandtlschen Grenzschichtdifferentialyleichungen
equation image
in G = (0, × (0, ∞) unter den Randbedingungen
equation image
betrachtet. Dabei werden zwei Fälle, nämlich ũ(y) > 0 für y > 0 und ũ(y) = 0 (d. h. das Fortsetzungsproblem und das Staupunktproblem), behandelt, indem mit Hilfe der v. Mises‐Transformation (*), (**) in
equation image
umgeschrieben wird. Das Problem (+) wird schließlich mit Hilfe der wohlbekannten Linienmethode gelöst; dabei ergeben sich neben Existenz‐ und Konvergenzsätzen auch quantitative Aussagen über das Verhalten der Lösung von (*), (**) am Rande von G und im Unendlichen.
Über die Lösbarkeit der Grundgleichungen der Strahlungshydrodynamik bei sehr kleiner und sehr großer Bouguer‐Zahl
Authors: Förste J. 
Published: June 2007

AbstractWir betrachten die Grundgleichungen der Strahlungshydrodynamik für sehr kleine und sehr große Bouguer‐Zahlen Bu. Für ebene instationäre Strömungen in einem beschränkten Gebiet wird ein Existenzsatz des Anfangs‐Randwertproblems bewiesen. Unter einer Zusatzvoraussetzung wird im Falle Bu < 1 ein Einzigkeitssatz gezeigt, während im Falle Bu > 1 die Frage der eindeutigen Bestimmtheit der Lösung offen bleibt.
On Optimal Control and Identification of Processes Governed by Parabolic Differential Equations of Second Order
Authors: Wolfersdorf L. V. 
Published: June 2007

AbstractMaximum principles of Pontryagin's type are derived for various classes of optimal processes governed by mildly nonlinear parabolic differential equations of second order. The considered functionals correspond to an observation of the processes in finitely many given points as occurring at identification of such processes.
Invertierung von 3‐diagonalen Matrizen
Authors: Grund Friedrich 
Published: June 2007

AbstractDie inverse Matrix zu einer 3‐diagonalen Matrix wird mit dem direkten bzw. Gaußschen Verfahren berechnet. Es zeigt sich, daß ein Element der inversen Matrix als Produkt von rekursiv berechenbaren Hilfsgrößen gefunden werden kann. Es werden Verbindungen zwischen den beiden Verfahren gezeigt und Stabilitätsaussagen gemacht. Eine Beziehung für die explizite Angabe der inversen Matrix zu gewissen Matrizen wird angegeben. Numerische Beispiele sind angeführt.
Ein Ansatz für die Werkstoffdämpfung zwei‐ und dreidimensionaler Kontinua
Authors: Grundmann H. 
Published: June 2007

AbstractZur phänomenologischen Beschreibung der Werkstoffdämpfung wird eine Verknüpfung zwischen der Mittelspannung und der Volumendehnung einerseits und den Komponenten des Spannungs‐ und Verzerrungsdeviators andererseits entwickelt, durch die der Energieverlust in Beziehung zur Volumen‐ und Gestaltänderungsarbeit gesetzt wird. Ein besonderer Vorteil des Ansatzes besteht darin, daß für periodische Bewegungen eine übersichtliche komplexe Schreibweise möglich ist, und daß sich eine Linearisierung in einfacher Weise anbietet.
Sequentielle Rangauswahlprobleme ‐ eine Erweiterung des „Secretary Problems”︁
Authors: Platen Eckhard 
Published: June 2007

AbstractFür sequentielle Rangauswahlprobleme, bei denen es sich um die Auswahl von m aus n (1 ≦ m ≦ n) sequentiell beobachtbaren Objekten ohne Rückgriffsmöglichkeit mit dem Ziel der Maximierung einer vorgegebenen Ertragsfunktion handelt, wird unter Voraussetzung einer bestehenden Rangfolge für die einzelnen Objekte die allgemeine Lösung angegeben. Davon ausgehend erfolgt die Lösung des speziellen Problems der Maximierung der Wahrscheinlichkeit für die Auswahl genau der m besten Objekte. Abschließend wird das asymptotische Verhalten der dabei gewonnenen optimalen Strategien bezüglich wachsender Objektanzahl n untersucht.
Zur Stabilität der Deformationen des tordierten elastoplastischen Kreiszylinders
Authors: Bruhns O. 
Published: June 2007

AbstractDie vorliegende Arbeit nimmt Bezug auf zwei kürzlich in der ZAMM erschienene Arbeiten von B. Raniecki und A. Sawczuk über Thermoeffekte in der Plastizitätstheorie [1. 2]. Im zweiten Teil dieser Arbeiten betonen die Autoren die Beteutung der Koppeleffekte in der Stabilitätstheorie thermoplastischer Deformationen. Dazu zeigen sie, daß das ‘Einschnür‐Versangen’ des tordierten dünnwandigen kreiszylindrischen Rohres als Folge von Thermoeffekten gedeutet werden kann. In der vorliegenden Arbeit wird nun gezeigt, daß dieses Beispiel einen Fehler enthalten muß. Bezogen auf dieses Beispiel erscheint daher die Bedeutung von Thermoeffekten für das Stabilitätsverhalten des betrachteten Körpers als zumindest fraglich.
Stochastic Stability of the Stationary Response of a System with Autoparametric Coupling
Authors: Ibrahim R. A. , Roberts J. W. 
Published: June 2007

AbstractThe paper relates to the response of a two degree of freedom vibratory system with non‐linear coupling of the type referred to as autoparametric, under the action of broadband stochastic excitation. In the particular arrangement considered, a broadband random force excites a primary vibratory system whose response acts as a random parametric loading of the coupled system with a consequent non‐linear reaction on the primary system. For such an arrangement earlier work has shown that large quasi‐stationary response of the coupled system may occur when the condition of internal resonance is realised. Otherwise stationary unimodal response of the primary system is obtained. In the present paper, the stability in the mean of the stationary response is investigated for a range of system parameters using a method based upon the Markov vector approach together with an approximate treatment of third and higher order statistical moments. The stability boundaries are determined from a numerical evaluation of the eigenvalues of a fourteenth order matrix derived from the dynamic moment equations and show the significant effect of the internal resonance detuning parameter. A further feature of the results is that beyond a certain value, increase of the primary system damping ratio appears to have a destabilising effect.
The Impact of Breast Cancer Genetic Risk Assessment on Intentions to Perform Cancer Surveillance Behaviors
Authors: Bennett Paul , Wilkinson Clare , Turner Jim , Griffith Gethin , France Barbara , Brain Kate , Gray Jonathon 
Published: June 2007

AbstractOne hundred and fifty‐four women undergoing breast/ovarian cancer genetic risk assessment completed questionnaires at entry into the Cancer Genetic Service for Wales (CGSW) assessment program and following risk provision, mapping the strength of intentions to engage in a number of preventive/surveillance behaviors, including seeing specialists, breast self‐examination, and involvement in screening programs, including mammography. A number of potential predictors of intentions were also assessed, including participants’ mood and emotional response to receiving risk information, the perceived benefits (in terms of reassurance and early disease detection) of engaging in each preventive behavior, and the perceived desires of their family and General Practitioner. Intentions to self‐examine did not change following risk provision, although strength of intentions to engage in some other preventive behaviors did lessen. Family and General Practitioners appeared to be strong social influences on behavioral intentions, as were the perceived benefits of gaining reassurance and/or early detection of disease.
Influence of stand age on nutrient and energy release through decomposition in alder‐cardamom agroforestry systems of the eastern Himalayas
Authors: Sharma G. , Sharma R. , Sharma E. 
Published: June 2007

AbstractThe influence of stand age (5, 10, 15, 20, 30 and 40 years) on the decomposition of litter fractions, nutrient and energy release of mixtures of N2‐fixing alder (Alnusnepalensis) and non‐N2‐fixing large cardamom (Amomum subulatum) systems was compared. Seasonal decomposition rates were distinct with the highest rate in the first 6 months followed by subsequent seasons. The decomposition rate was substantially high in younger stands (10‐ to 15‐years) and declined in the older stands. Heat sink from the stand floor litter increased from 171 × 106 kJ year−1 in 5 years to 299 × 106 kJ year−1 at 15 years and then considerably decreased with advancing age. However, energy and nutrient releases were slow at a high initial lignin‐to‐initial N ratio and C‐to‐N ratio, and there was an inverse relationship between the k‐value of ash‐free‐mass and N expressed as a function of the C‐to‐N ratio. Quantities of nutrient release and energy loss per unit area in 24 months of decomposition were highest in 15 years and subsequently they lowered with advancing age. Nutrient loss indicated approximately uniform absolute and relative rates. Absolute energy consistently decreased by 81–88% in 24 months. Ash‐free mass of decomposing litter remaining at different retrieval dates was associated with a narrowing of the C‐to‐N ratio. The relative loss rate of ash‐free mass, nutrients and energy content was strongly related to the C‐to‐N ratio, litter temperature and litter moisture. The influence of Alnus in the younger stands on nutrient and energy releases were rapid, indicating accelerated nutrient cycling and energy dynamics. The intensity of the processes was highly phenomenal and considerably high in younger stands up to 20 years. Thus, an appropriate management cycle of the Alnus‐cardamom system for sustainability is 15–20 years.
Seasonal variation in fleshy fruit use and seed dispersal by the Japanese black bear (Ursus thibetanus japonicus)
Authors: Takahashi Kazuaki , Shiota Tadatoshi , Tamatani Hiroo , Koyama Masaru , Washitani Izumi 
Published: June 2007

AbstractFruit use by the Japanese black bear (Ursus thibetanus japonicus) and seed clumping in bear scat were studied in central Japan using fecal analyses. Between May and November 2003 and 2004, the life form and fruit size of plants consumed by bears and the species composition and intactness of seeds contained in scat were examined in five transects (approximately 10 km × 10 m) in broad‐leaved deciduous forests. In 2003, scats with seeds were found only in the autumn, when fruiting trees and shrubs were abundant. In 2004, scats with seeds occurred intermittently from the summer, when fruiting plants were rare, up to the autumn. Yearly and seasonal variation in fruit use reflects the opportunistic foraging behavior of Japanese black bears. Seven of the nine plant species detected in scats had medium‐sized fruits (6–15 mm width), whereas the other two species had relatively large fruits (20–100 mm width). In total, 14,492 seeds were detected, of which 97.6% were intact; the remainder were damaged. Intact seeds of one or two species were found in each scat. The number of intact seeds per scat ranged from 1 to 5476. Japanese black bears seldom digest ingested seeds, thereby contributing to the seed dispersal of their food plants, including species with fruits that are too large to be swallowed by frugivorous birds.
Characterization of Turkish Quercus L. Taxa Based on Fatty Acid Compositions of the Acorns
Authors: Özcan Tamer 
Published: June 2007

AbstractTotal oil content and the composition of fatty acids were analyzed in the acorns of 16 Quercus taxa from Turkey. The range of total fat varied between 0.7 and 7.4%. Oleic (10.2–54.4%), linoleic (24.2–49.1%), palmitic (13.4–30.4%), alpha linolenic (1.5–8.6%) and stearic acid (1.5–4.5%) were major fatty acids for all taxa. Significantly differences at section level were found (p < 0.05) for palmitic, stearic and oleic acid concentration. Saturated (17.0–38.6%), mono unsaturated (11.0–55.5%) and unsaturated fatty acids (57.4–81.6%) in total oil were also significantly different between section Quercus, Cerris and Ilex (p < 0.05). In addition, sectional differences were significant (p < 0.02) for the relative concentrations of saturated fatty acids compared to mono, poly and total unsaturated fatty acids. Considerable variation of individual fatty acid levels were observed in related species and varieties. The species from section Ilex Loudon exhibited the highest levels of saturated fatty acid while the lowest levels were found in Q. brantii, Q. libani and Q. trojana from section Cerris Loudon. These species also had the highest levels of unsaturated fatty acids. Whereas the lowest values were detected in the species of section Ilex. Both varieties of Q. cerris showed significant differences (p < 0.05) from the other species in section Cerris for all parameters, except for stearic acid and exhibited little variations among their individual populations. Different concentrations of fatty acids may be useful biochemical markers for the characterization of Quercus at the infrageneric level. Interesting ratios of linoleic:α‐linolenic acid especially in Q. robur ssp. robur, Q. hartwissiana, Q. vulcanica, Q. ithaburensis ssp. macrolepis and Q. libani also were detected with respect to dietary reference for fatty acid intake.
Burden of illness among commercially insured patients with Alzheimer's disease
Authors: Joyce Amie T. , Zhao Yang , Bowman Lee , Flynn Jennifer A. , Carter Chureen T. , Ollendorf Daniel A. 
Published: June 2007

BackgroundThe purpose of this study was to examine the direct costs of care for patients newly diagnosed with Alzheimer's disease (AD) by using retrospective healthcare claims data.MethodsPatients aged 65 years or older with ≥1 claims containing a listed diagnosis of AD between January 1999 and November 2003 were selected. The first observed AD claim was deemed the index date. Control patients with no evidence of AD or dementia also were identified. Patients had a 12‐month pre‐index period and minimum 30‐day follow‐up. AD patients were matched to control patients on the basis of age, gender, and follow‐up duration. Annualized utilization and costs were calculated; generalized linear models (GLM) were undertaken, controlling for demographic and clinical characteristics. Analyses focused on differences in costs among AD patients and controls.ResultsThe average age of AD and control patients was 82 years; 38% were men (n = 2,475 AD; 4,950 controls). Average total costs for AD patients were more than five‐fold higher compared with controls ($28,263 vs $5,880; P < .001), driven primarily by inpatient costs. Total costs were significantly higher (P < .001) for AD patients in GLM modeling, with diagnosis group (AD vs control) as the most important predictor. Adjusted annual costs per patient were also five‐fold higher ($21,150 vs $4,053 for AD vs control, respectively) during the follow‐up period.ConclusionsThe annual economic burden of AD to third‐party payers is more substantial than previously estimated ($3,805 to $8,200).
Comparison of Alzheimer's disease in American Indians, whites, and African Americans
Authors: Weiner Myron F. , Hynan Linda S. , Beekly Duane , Koepsell Thomas D. , Kukull Walter A. 
Published: June 2007

BackgroundThe recent development of a national Alzheimer's disease database makes it possible to compare the course of illness in various ethnic groups.MethodsThe National Alzheimer's Coordinating Center database was used to compare the clinical presentation and course of Alzheimer's disease (AD) in American Indians with whites and African‐Americans, and to compare findings in American Indians seen in Oklahoma with those seen elsewhere. We ascertained the diagnosis of probable and possible AD, gender, education, history of affected first‐degree relative, depression, history of stroke, Parkinson symptoms, age at onset of dementia, initial visit, and death. We also ascertained years from symptom onset and initial evaluation to death, initial Mini‐Mental State Exam (MMSE) score adjusted for education, and years from onset of symptoms.ResultsData from 30,993 subjects were analyzed. There were statistically significant but only small differences between groups. American Indians had the lowest proportion of affected first‐degree relatives, depression, and extrapyramidal symptoms. Whites had the highest proportion of subjects with affected first‐degree relatives and depression, but the lowest history of stroke. African Americans had the most frequent history of stroke and extrapyramidal symptoms. Indians seen in Oklahoma had a lower proportion of affected first‐degree relatives than did those seen elsewhere.ConclusionsAlthough there were no clinically significant differences in course of illness between these self‐identified ethnic groups, this finding with regard to American Indians must be interpreted with caution, because the subjects for whom we had information regarding ancestry reported a smaller proportion of American Indian (25%) than white (75%) heritage.
Forecasting the global burden of Alzheimer's disease
Authors: Brookmeyer Ron , Johnson Elizabeth , Ziegler‐Graham Kathryn , Arrighi H. Michael 
Published: June 2007

BackgroundOur goal was to forecast the global burden of Alzheimer's disease and evaluate the potential impact of interventions that delay disease onset or progression.MethodsA stochastic, multistate model was used in conjunction with United Nations worldwide population forecasts and data from epidemiological studies of the risks of Alzheimer's disease.ResultsIn 2006, the worldwide prevalence of Alzheimer's disease was 26.6 million. By 2050, the prevalence will quadruple, by which time 1 in 85 persons worldwide will be living with the disease. We estimate about 43% of prevalent cases need a high level of care, equivalent to that of a nursing home. If interventions could delay both disease onset and progression by a modest 1 year, there would be nearly 9.2 million fewer cases of the disease in 2050, with nearly the entire decline attributable to decreases in persons needing a high level of care.ConclusionsWe face a looming global epidemic of Alzheimer's disease as the world's population ages. Modest advances in therapeutic and preventive strategies that lead to even small delays in the onset and progression of Alzheimer's disease can significantly reduce the global burden of this disease.