bluuebunny/crossref_metadata_2025 huggingface dataset:
Attitudes towards health and illness among exercisers and non‐exercisers
Authors: Kirkcaldy Bruce , Furnham Adrian , Shephard Roy
Published: June 2007

Two hundred working German adults (100 M, 100 F) of working age completed the German version of the questionnaire Attitudes Towards Health and Medicine. The sample was partitioned into those exercising on a regular basis (exercisers) and those who scarcely participated in physical exercise (non‐exercisers). There was no evidence that exercisers differed significantly from non‐exercisers on the subscales of health consciousness, nor did they differ on any of the subscales of provider control over personal health. Nevertheless, differences in health‐related attitudes between exercisers and non‐exercisers emerged when the moderating effects of age were considered (particularly on the scale ‘provider control over health’). The active younger adults were less sceptical regarding the value of medical advice, and further believed in their ability to control their own health. Furthermore, they expressed less nutritional concern but greater health consciousness than their sedentary peers. On the other hand, among the over‐40s, the exercisers displayed less respect for the health provider than did the non‐exercisers. Similarly, age had an impact on the leisure time‐health attitude relationship; high‐leisure middle‐aged adults (31–40 years) showed lower scores on provider control over health. It is suggested that particularly for middle‐aged individuals, insistence on medically supervised exercise prescription and programming offers an unnecessary barrier to exercise adoption and compliance.
Stress effects on the health of chief executives of business organizations
Authors: Robinson Paul , Inkson Kerr
Published: June 2007

Ninety‐eight chief executive officers of business organizations employing at least 150 staff completed a battery of questionnaires measuring chronic and episodic non‐work‐related and work‐related stressors; trait anxiety, locus of control, and type A/type B personality; health‐related lifestyle practices; and behaviours related to coping with stress. The medical history and blood pressure and blood chemistry measures of each respondent were assessed by a panel of medical experts and an index of physical health risk was computed. Factor analysis was used to refine measures of key dimensions of episodic and chronic work‐related stress, and coping behaviours. Physical health risk was regressed as a dependent variable on to the independent variables of stressors, personality traits, and coping and health behaviours. Fifty‐seven per cent of the variance in health risk was accounted for, with the four types of stressor, anxiety, lifestyle habits and ‘self‐control’ coping mechanisms all contributing to the regression equation. The results particularly indicated the contribution of non‐work‐related stressors to physical health risk, and the moderating effects of lifestyle habits.
Psychiatric morbidity in policemen and the effect of brief psychotherapeutic intervention — a pilot study
Authors: S. Ronald , Curtis David , Isaacs Geoffrey
Published: June 2007

The level of psychiatric morbidity and perceived sources of stress among police officers were investigated using the General Health Questionnaire (GHQ) and a stress situation questionnaire, which were sent to 171 officers. Half of the responders were invited to attend group counselling sessions weekly for 12 weeks. Outcome measures studied were a second GHQ completed at the end of the treatment period and the amounts of sick leave taken in the 12‐week period before, during and after the treatment period. The results were that 61 people returned the first GHQ of whom 59 were male and of whom 14 were classed as ‘cases’. Of the 31 assigned to the treatment group, 22 attended at least one session. Responses to the stress situation questionnaire and the content of counselling sessions tended to confirm the impression that internal aspects of the organization were viewed as prime sources of stress and dissatisfaction. There were no significant changes in GHQ score within or between groups, nor were there significant differences in the amount of sick leave taken. Nevertheless the sessions appeared to be valued and we conclude that this sort of intervention is at least feasible. We recommend that similar studies measure psychiatric morbidity during treatment and at follow‐up, rather than immediately after finishing, when reactions to this termination are prominent.
Towards an understanding of work satisfactions and emotional well‐being of school‐based educators
Authors: Burke Ronald J. , Greenglass Esther R.
Published: June 2007

This study examined a research model developed to understand work satisfaction and emotional and physical well‐being of teachers. Data were collected from 833 school‐based educators using questionnaires completed anonymously. Five groups of predictor variables identified in previous research were considered: individual demographic and situational variables, work stressors, role conflict, social support and components of psychological burnout. Some support for the model was found. Individual demographic characteristics, work stressors and components of psychological burnout were strong predictors of work attitudes and emotional and physical health. Social support had little effect on these dependent variables.
Short‐term psychotherapy of acute adult onset post‐traumatic stress: The role of weltanschauung
Authors: Everly George S.
Published: June 2007

Within the science of psychotraumatology there is compelling evidence that the interpretation of a given traumatic event can serve to augment or mitigate the subsequent post‐traumatic psychiatric sequelae. Psychological traumata exert their greatest adverse impact by contradicting the weltanschauung, in this case the patient's concept or particular view of life regarding safety and security. This article discusses the nature and treatment of acute adult onset post‐traumatic stress by focusing upon the violation of the weltanschauung and strategies that may be of value in resolving that violation.
Symptom laterality and psychological presentation in chronic pain syndrome
Authors: Levine John B. , Weisgerber Karen , Nehme Anne‐Marie , Mitra Nina
Published: June 2007

This study examined whether a subgroup of chronic pain patients would evidence laterality of somatic pain complaints, and whether there would be a relationship between laterality and: (a) intensity of psychological distress and (b) type of psychological distress. MMPI profiles were obtained from 152 patients. Patients were also asked to localize their pain on the Body Pain Diagram. There was no overall difference in sidedness of complaints for this cohort. However, patients with relatively elevated MMPI profile patterns showed a strong tendency to lateralize their symptoms towards the left side of the body. In contrast, patients with a suppressed profile of the ‘conversion v’ variety evidenced laterality of pain complaints towards the right side of the body. Possible implications for a neuropsychological model of somatoform pain symptoms are discussed.
Can stress cause coronary heart disease?
Authors: Latham Peter Mere , Rosch Paul J.
Published: June 2007

There are things which will not be defined, and Fever is one of them. Besides, when a word has passed into everyday use, it is too late to lay a logical trap for its meaning, and think to apprehend it by a definition.
A longitudinal study of reciprocal relationships between psychological dysfunction and role satisfaction among married and single adults
Authors: Liu Xiaoru , Kaplan Howard B.
Published: June 2007

Theoretically informed longitudinal models specifying the reciprocal relationships between psychological dysfunction and role satisfaction are estimated in a sample of young adults from a general population. The subjects were initially studied as seventh‐graders (in 1971) and were later followed up as young adults at two points in time. The specified models are estimated separately for both married and single/never‐married subjects using the LISREL VII computer program. The results are consistent with the hypothesis that psychological dysfunction and role satisfaction are mutually influential over time in both the married and never‐married groups. The observed effects are robust in the presence of stability effects and common antecedent variables including educational attainment, gender, race and time of follow‐up interview.
Lipid‐lowering therapy and violent death: Is depression a culprit?
Authors: Ketterer Mark W. , Brymer James , Rhoads Ken , Kraft Phillip , Goldberg A. David , Lovallo William A.
Published: June 2007

Large‐scale, controlled treatment studies of antilipidemic therapy have yielded consistent evidence of reduction in cardiovascular morbidity and mortality, but no reduction in total mortality. This counterhypothetical result appears to be due to a compensatory increase in cancer and violent death with treatment. ‘Violent death’ includes suicides, homocides and accidents. The present study took advantage of a dataset on 174 males undergoing coronary angiography which included presence/absence of an antilipidemic medication regimen and multiple measures of emotional distress/dysfunction to see if the two were associated. Self‐reported depression on the Ketterer Stress Symptom Frequency Checklist (KSSFC) was higher in these angiographic male patients if they were on medical treatment for hypercholesterolemia than if they were not. Comparisons across antilipidemic groupings of a number of potential confounding/mediating variables revealed no systematic differences which can account for these results. While only correlational in nature, present results are consistent with the hypothesis that antilipidemic drug treatment induces emotional distress in males undergoing coronary angiography.
The effect of stressful behavioural exposure on endocrine and immune parameters in the rat
Authors: Song Cai , Kelly John P. , Leonard B. E.
Published: June 2007

Stress and depression are associated with a variety of alterations in the endocrine and immune systems. Leucocyte adhesiveness/aggregation (LAA) has recently been proposed as a simple indicator of stress in humans. The objective of the present study was to examine the serum concentration of corticosterone, neutrophil phagocytosis, lymphocyte proliferation, LAA and differential white blood cell (WBC) count in rats at different time intervals following an exposure to the behavioural despair and ‘open field’ tests. Thirty min following exposure to the behavioural despair test, the concentration of corticosterone was significantly elevated. An increase in the percentage of neutrophils and LAA, and a decrease in the percentage of lymphocytes and monocytes in the WBC count, were also found 30 min and 60 min after exposure to both the behavioural despair and ‘open field’ tests. A reduction in neutrophil phagocytosis was also observed 60 min after the exposure to these situations. The results show that there are endocrine and immune changes following exposure to these experimental situations. LAA appears to be a particularly useful indicator of acute stress in rats.
Influence of stress and blood type on Toxicity‐preventing activity and other cardiac risk factors
Authors: Neumann Joseph K. , Arbogast Loretta Y. , Dubberley F. Aaron
Published: June 2007

ABO blood type has been shown to be associated with both cardiovascular risk and toxicity‐preventing activity (TxPA) stress response in elderly males. Twenty middle‐aged, healthy males, 14 blood type A and six blood type O, were involved in this project. Volunteers completed a battery of psychological assessments, then gave blood and had several psychophysiological measures taken prior to, during and after two stressors. The stressors consisted of mental arithmetic tasks plus audiotapes of combat sounds and a baby crying. The anger‐out and hard‐driving scores of blood type O subjects were significantly higher than the blood type A means. TxPA decreased significantly as a function of stress and some suggestive blood type effects of TxPA were found. Plasma protein, microhematocrit, plasma cortisol, finger temperature, skin conductance, blood pressure and two facial electromyograph (EMG) variables were also significantly affected by stressors but not by the blood type factor. No significant differences of any kind were found for total cholesterol, high‐density lipoprotein or pulse variables. The importance of age and other individual subject characteristics was discussed.
Heart rate changes in chronic insomnia
Authors: Stepanski Edward , Glinn Michele , Zorick Frank , Roehrs Timothy , Roth Thomas
Published: June 2007

This study assessed physiological activity in patients with chronic insomnia before sleep, during sleep and in response to acute stress. Twenty‐four subjects with chronic insomnia and 25 normal sleepers slept in the laboratory overnight and were given a stressful performance task in the morning. Heart rate was significantly higher in the insomniac group at night. The next morning, heart rate was not different at baseline, but was significantly higher during the performance task in the insomniac group. These results are discussed as supporting the notion that insomniacs have greater physiological responsivity to stress. Further research is needed to determine if altered physiological activity is a cause or consequence of insomnia.
Adverse impacts experienced by police officers following exposure to sex discrimination and sexual harassment
Authors: Phd Jennifer Brown , Campbell Elizabeth A. , Fife‐Schaw Christopher
Published: June 2007

Adverse psychological and physical impacts have been related to experience of detriment arising from sex discrimination. In the present study detriment was operationalized in terms of differential career progress, unequal access to organizational benefits and experience of sexual harassment. A national UK sample of 1802 police women, 510 police men and 164 civilian women took part in the study. Results revealed gender differences in exposure to detriment and the suffering of associated adverse impacts. Subjective rating of impacts by police women revealed the greatest impact to be associated with frustrated career progression and the least from experience of sexual harassment. A multiple regression analysis suggested the reverse order when predicting elevated GHQ(28) scores for women officers. This is accounted for by cultural factors, which are also proposed to be influential in rates of reporting sources of discrimination.
Stress management for psoriasis patients: The effectiveness of biofeedback and relaxation techniques
Authors: Keinan Giora , Segal Alexander , Gal U. , Brenner Sara
Published: June 2007

Previous studies have found evidence of a connection between stress and the appearance of psoriasis symptoms. It was therefore hypothesized that stress management techniques such as biofeedback and relaxation could be effective in ameliorating the severity of the symptoms. Thirty‐two psoriatics were randomly divided into three groups, one trained in biofeedback and relaxation techniques, one in relaxation alone and the third receiving no treatment. The subjects' condition was evaluated by a physician at the start and end of the 3‐month study. Additionally, at the end of the study, the subjects were asked to assess the degree to which their symptoms had improved relative to the start of the study and relative to the same season of the previous year. The results indicated that, in comparison to the waiting list group, the biofeedback and relaxation group reported considerable improvement in their condition relative to the same season of the previous year. No significant differences were found between the groups regarding the degree of improvement relative to the start of the study. It is suggested that the fact that psoriasis is subject to seasonal variations may account for the differential findings.
Stress in nurses: The effects of coping and social support
Authors: Tyler Patrick , Cushway Delia
Published: June 2007

Sources of stress, job satisfaction and coping were investigated in 245 general hospital nurses using standardized questionnaires. It was hypothesized that coping strategies, social support and job satisfaction would moderate or buffer the effects of the stressor on psychological distress, such that those who were lower in coping skills, social support and job satisfaction would be more reactive to stress effects. Negative main effects on mental well‐being, as measured by the General Health Questionnaire, were found for workload, lack of social support, inadequate preparation, conflict with other nurses, conflict with doctors and use of avoidance coping strategies. Proposed buffering effects were investigated using multiple regression analysis to control for the main effects. Although consistently in the predicted direction, the buffering effects were found to be very small and non‐significant. It was concluded that for stress in nurses the results supported a transactional model rather than an interactive model for social support and coping.
Review of bus drivers' occupational stress and stress prevention
Authors: Kompier Michiel A. J. , Di Martino Vittorio
Published: June 2007

Although heterogeneous in methodology and content, 32 studies from 13 countries on bus drivers' work and health are similar in their conclusions. Bus‐driving–characterized by high demands, low control and low support – can be regarded as a classic example of high‐strain occupation, with high risks of physical and mental occupational ill‐health, leading to absenteeism and to decreased productivity of employees and enterprises. Several recommendations – some of them already being implemented by bus companies – are presented in order to reduce work stress in bus drivers. They relate to: (a) ergonomics of the bus cabin, (b) job rotation and ‘combination jobs’, (c) timetables, shift schedules and quality of break periods, and (d) the social work environment and management style. Stress monitoring and stress reduction is not merely a technical process based on a technical analysis and on the simple ‘straightforward’ realization of recommendations and findings. It relates to changing and improving organizations and organizational processes. Such organization changes can best be obtained through a stepwise and participative approach. There are indications that those companies that invest in preventive measures receive their rewards.
Identifying A psychological profile of Type A behaviour pattern
Authors: Sibilia Lucio , Picozzi Roberto , Nardi Anna Maria
Published: June 2007

A conceptual model of Type A behaviour pattern (TABP) is presented which frames the pattern in terms of current cognitive‐behavioural psychology and in the wider context of the psychosocial risk factors of CHD. Type A behaviours are considered as stemming from Type A appraisals, elicited in specific situations in individuals with enhanced emotional reactivity who hold a system of beliefs identifiable as Type A. A study was performed in order to assess the possible associations of personality dimensions such as extraversion and neuroticism to TABP and identify specific dysfunctional beliefs associated with TABP. The Bortner Rating Scale (BRS) was administered as a measure of TABP, together with the Maudsley Personality Inventory (MPI) for measuring extraversion and neuroticism and a shortened version of the Dysfunctional Attitude Scale (DAS), in a random subsample of a male white‐collar population screened in the worksite for cardiovascular risk factors (N= 200). BRS scores showed a high direct correlation with DAS total scores (r= 0.64), a significant one with neuroticism (r= 0.29) and a weaker one with extraversion (r= 0.15). DAS was factor analysed and a solution found identifying eight factors. Two of them were correlated with TABP, namely ‘support‐reliance’, directly correlated, and ‘self‐confidence’, inversely. At a robust stepwise multiple regression analysis, using the above psychometric measures as independent variables and BRS scores as dependent variable, a model was found accounting for 35 per cent of variance of TABP distribution. The findings give partial support to the model proposed. The identified dysfunctional beliefs involved a higher sense of dependency of Type A individuals. A prospective study is under way to assess the possible predictive power of these cognitive factors. If confirmed, the model could partially account for inconsistencies of empirical findings in TABP studies.
Convective Instability in a Rotating Viscoelastic Fluid Layer
Authors: Bhatia P. K. , Steiner J. M.
Published: June 2007

Es wird die Überstabilität in einer viskoelastischen Flüssigkeitsschicht, die von unten erhitzt wird, bei Vorhandensein von Coriolis‐Kräften untersucht. Für eine Maxwellsche Flüssigkeit werden die Eigenlösungen a) bei zwei freien, b) bei zwei starren Rändern gewonnen. Wie sich herausstellt, hat Rotation auf den Überstabilitätsmodus der Konvektion in einer viskoelastischen Flüssigkeitsschicht einen destabilisierenden Einfluß. Dieses Ergebnis ist dem stabilisierenden Einfluß einer Rotation im Falle einer gewöhnlichen viskosen Flüssigkeit gegenüberzustellen.
Eine Erweiterung des Verfahrens der Zwischenschritte auf allgemeinere parabolische und elliptische Differentialgleichungen
Authors: Wirz H. J.
Published: June 2007

Zur angenäherten numerischen Berechnung der Lösung von allgemeineren parabolischen Anfangsrandwertaufgaben werden implizite zweischichtige Differenzenschemata einfacher und höherer Annäherung (Mehrstellenformeln) in Erweiterung der Methode der Zwischenschritte vorgestellt.
Investigations Concerning Heat Transfer Involving Conical Structures
Authors: Oberhettinger F. , Dressler R. F.
Published: June 2007

Das in dem Gebiet zwischen zwei endlichen koaxialen Kreiskegeln herrschende Temperaturfeld wird im isothermischen und im adiabatischen Fall untersucht, wobei die Temperaturverteilung als rotationssymmetrisch bezüglich der Achse angenommen wird.
Zur stetigen Abhängigkeit des Extremalwertes eines konvexen Optimierungsproblems von einer stetigen Änderung des Problems
Authors: Krabs W.
Published: June 2007

In dieser Arbeit wird das Problem behandelt, ein konvexes Funktional unter konkaven Nebenbedingungen auf einer konvexen Teilmenge eines linearen Raumes zum Minimum zu machen. Es wird gezeigt, daß sich der gesuchte Extremalwert des Funktionals unter geeigneten Voraussetzungen stetig ändert, wenn die im Problem vorgegebenen Größen stetig abgeändert werden. Die Ergebnisse werden angewandt auf Approximationsprobleme in normierten Räumen und Optimierungsaufgaben mit unendlich vielen Nebenbedingungen, bei denen die stetige Änderung des Problems durch Diskretisierung (Übergang zu Halbnormen oder endlich vielen Nebenbedingungen) durchgeführt wird.
Large Elasto‐Plastic Deflection of a Circular Plate of Mild Steel under Cyclic Loading
Authors: Ohashi Y. , Kawashima K.
Published: June 2007

An elasto‐plastic bending of a thin circular plate of mild steel subjected to a cyclic loading is analysed by using the actual stress‐strain relation of the material under cyclic loading. A numerical analysis of a simply supported circular plate under uniform lateral pressure with alternating sign is performed for first three half cycles. The analytical result is compared with the corresponding experimental one. It is shown that the proposed analysis gives a close approximation for the deflection of the plate and can deal well with the Bauschinger effect in the actual cyclic deformation.
Vergleich von Tschebyscheff‐Integrationsmethoden
Authors: Wagner H.‐J.
Published: June 2007

Das Integral einer Funktion f ist unter Verwendung von Tschebyscheff‐Polynomen zu approximieren. Man kann entweder f(x) oder f(x) √1−x2 entwickeln und die Stützstellen geeignet wählen. Es wird gezeigt, welche Methode für ein gegebenes f am günstigsten ist.
On natural states and plastic strain in simple materials
Authors: Holsapple K. A.
Published: June 2007

In der folgenden Arbeit wird gezeigt, wie das Modell der plastischen Dehnungen als spezielle und nützliche Eigenschaft gewisser Materialien mit lang anhaltendem Gedächtnis (long‐range memory) eingeführt werden kann. Es werden Einschränkungen des Materialverhaltens abgeleitet, die der Existenz von plastischen Dehnungen genügen und ungefähr folgendermaßen beschrieben werden können: man verlangt, daß das Material ein nicht nachlassendes Gedächtnis (non‐fading memory) und ein bestimmtes Festkörperverhalten hat. Der Vorteil dieses Modells für allgemeinere Theorien als die klassische elastisch‐plastische Theorie wird anhand von zwei Anwendungen dargelegt: Die Formulierung einer Plastizitätsfunktionaltheorie und die Aufstellung einer Theorie der wandernden Versetzungen, beides im Rahmen der Theorie der einfachen Materialien mit Gedächtnis (simple materials with memory).
Elasto‐plastic stress analysis of prismatic bar under combined bending and torsion
Authors: Ishikawa H.
Published: June 2007

In this paper, the elasto‐plastic problem of combined bending and torsion of a straight prismatic bar, loaded by a terminal bending couple about the axis of symmetry of the cross section and a twisting couple, is treated analytically for an incompressible isotropic work‐hardening material obeying a nonlinear stress strain law. Evolving a theory so as to satisfy the equilibrium and compatibility condition, the basic nonlinear differential equation in the ordinal Cartesian coordinate system can be linearized, adopting the new parameter in the stress space. Provided that the Ramberg‐Osgood's law is employed as a nonlinear stress strain relation, the linearized basic equation can be reduced to the hypergeometric differential equation. Then, the components of strain and corresponding coordinates can be described in the form of the hypergeometric series. The stress components, the bending and twisting moment can be evaluated by the numerical calculation.
Nonlinear singular multipoint boundary value problems
Authors: Jerome J. W.
Published: June 2007

Let Λ be a linear differential operator on (a, b) of order 2m with leading coefficient possessing an integrable reciprocal. Global C(m‐1)(a, b) solutions are shown to exist for certain nonlinear multipoint boundary value problems of the form A u = F(u, …, u(m‐1), where linear combinations of derivatives through order m – 1 are specified at points interior to (a, b). The associated linear problem is completely solved through the construction of an appropriate Green's function which determines a compact operator G = A−1. The linear eigenvalue problem is examined and a complete orthonormal system exhibited in L2(a, b). Solutions of the nonlinear problem are obtained by exhibiting fixed points for the operator GF.
Verhalten von Dämpfen löslicher Zweistoffgemische bei Expansion in Überschalldüsen — Tropfenkoaleszenz in einer Potentialwirbelströmung)
Authors: Kaser A.
Published: June 2007

Das Verhalten von Dämpfen löslicher Zweistoffgemische bei Expansion in Überschalldüsen wird aufgezeigt und die Möglichkeit einer Komponententrennung und Abscheidung des sich in Tröpfchenform bildenden Kondensats untersucht. Mittels der Klassischen Keimbildungstheorie und der Kondensationsgleichungen werden in Verbindung mit thermodynamischen Gesetzen Beziehungen hergeleitet, die den Kondensationsvorgang hinreichend beschreiben, den Einfluß gewisser Stoffeigenschaften klar erkennen lassen, insbesondere die Verschiebung der Kondensatzusammensetzung in Richtung der Komponente mit dem kleineren Molvolumen als Funktion von Tropfengröße und Übersättigung, und eine Vorhersage der erzielbaren Restdampfanreicherung erlauben. Im Hinblick auf den Versuch einer Trennung der flüssigen Phase vom abströmenden Restdampf wird schließlich auf Koaleszenzvorgänge grundsätzlich eingegangen, im besonderen die Wirkung der Koaleszenz auf das Tropfenwachstum im Strömungsfeld eines Potentialwirbels abgeschätzt und am Beispiel des Binärsystems Äthylalkohol‐Wasser diskutiert.
Ein explizites Charakteristikenverfahren zweiter Ordnung für das Anfangswert‐problem bei quasilinearen hyperbolischen Differentialgleichungssystemen erster Ordnung mit zwei unabhängigen Veränderlichen
Authors: Demmig F.
Published: June 2007

Für die numerische Lösung von Anfangswertaufgaben bei quasilinearen hyperbolischen Differentialgleichungssystemen erster Ordnung wird ein explizites Charakteristikenverfahren zweiter Ordnung angegeben. Es wird bewiesen, daß die expliziten Formeln lokal eine Approximation zweiter Ordnung ergeben, und es werden praktische Hinweise gegeben. Die Methode enthält keine Iterationsprozeduren mit schlecht definierter oder redundanter Anzahl von Iterationen und kann in modifizierter Form auch zur Lösung von Randwertaufgaben verwendet werden.
The effects of couple‐stresses on thermal stress distributions in multiply‐connected domains
Authors: Takeuti Y. , Yamazato K.
Published: June 2007

The effects of couple‐stresses on the plane thermoelasticity in a multiply‐connected domain are treated for some specific problems. The conditions for the single‐valuedness of displacements and rotation, i. e., modified Michell's conditions are first derived for the finite domains with many holes with consideration of couple‐stresses. Numerical works are carried out for the distributions of thermal stresses in a hollow circular cylinder subjected to steady nonaxisymmetrical arbitrary temperature distribution on the boundary, and in an infinite elastic medium with a circular cylindrical cavity under uniform heat flow.
A third order differential equation arising in fluid mechanics
Authors: Heidel J. W.
Published: June 2007

The third order nonlinear boundary value problem (1.1), (1.2) is discussed. Rasmussen has proven existence for a ≧ O, b ≧ O, μ < O. Here uniqueness for this range of parameter is established under the additional assumption that y′ ≧ O. Then growth estimates for μ < O are given. Finally, the existence of solutions for (1.1), (1.2) when μ < O is discussed. Use is made of the invariance of (1.1) under the transformation x(t) = cy(ct).
Fehleruntersuchungen zur Lösung des inhomogenen natürlichen Randwertproblems durch einen Ritzschen Ansatz mit standardisierten Koordinatenfunktionen
Authors: Hantzschmann K.
Published: June 2007

Für das Ritzsche Verfahren zur Lösung von Randwertproblemen m‐ter Ordnung im Raum Wn der stückweise aus Polynomen vom Grad 2 m — 1 zusammengesetzten Funktionen φ(x) mit φ(x) ε C(m)[a,b] werden unter Benutzung der Theorie der Integrodifferentialgleichungen Fehleruntersuchungen durchgeführt. Der Verfahrensfehler erweist sich von der gleichen Ordnung h2m wie der Fehler der im Raum Wn Möglichen Hermite‐Interpolation. Zur Berechnung der Integrale werden der Ordnung des Verfahrens angepaßte Quadratur formeln bereitgestellt. Unter Verwendung einer elementar auswertbaren Greenschen Funktion G(x, s) sind praktisch gut nutzbare Fehlerschranken für den Gesamtfehler entwickelt worden.
Pressure Drop Due to the Motion of Neutrally Buoyant Particles in Duct Flows. III. Non‐Neutrally Buoyant Spherical Droplets and Bubbles
Authors: Bungay P. M. , Brenner H.
Published: June 2007

By means of a reciprocity relation, a formula is derived which gives the pressure drop experienced by a non‐neutrally buoyant spherical droplet translating in Stokes flow within a cylindrical duct through which a viscous fluid is flowing.
Optimale Formen des dünnwandigen geschlossenen Querschnitts eines auf Biegung beanspruchten Balkens
Authors: Thermann A. Mioduchowski/K.
Published: June 2007

Es wird des Problem des optimalen Querschnittsprofils eines auf Biegung beanspruchten Balkens gelöst. Zielfunktion ist das Gewicht des Stabes. Die Restriktionen, die sich im Rahmen der Stabtheorie formulieren lassen — beschränkte Spannungen und Kippstabilität — werden berücksichtigt. Ein Versagen durch örtliches Ausbeulen wird jedoch ausgeschlossen.
Über die Periode nichtlinearer Schwingungen autonomer dynamischer Systeme n‐ter Ordnung
Authors: Schneider K. R.
Published: June 2007

In der vorliegenden Arbeit werden hinreichende Bedingungen abgeleitet, unter denen ein autonomes dynamisches System in einem vorgegebenen Gebiet des Phasenraumes keine geschlossene Trajektorie besitzt, deren Periode einem vorgegebenen Intervall angehört. Die erhaltenen Bedingungen gestatten in gewissen Fällen die Angabe einer unteren Schranke für die Periode einer beliebigen Schwingung. Im letzten Teil der Arbeit wird ein Verfahren angegeben, mit dem zu einer vorgegebenen ω0‐periodischen Lösung p(t) Umgebungen ermittelt werden können, die keine von p(t) verschiedene ω0‐periodische Lösung enthalten.
A unified approach to the solution of plane problems of Magneto‐elasticity with special reference to a hole in a thin infinite conducting plate
Authors: Chakrabarti A. , Amarnath A.
Published: June 2007

Under certain specific assumption it has been observed that the basic equations of magneto‐elasticity in the case of plane deformation lead to a biharmonic equation, as in the case of the classical plane theory of elasticity. The method of solving boundary value problems has been properly modified and a unified approach in solving such problems has been suggested with special reference to problems relating thin infinite plates with a hole. Closed form expressions have been obtained for the stresses due to a uniform magnetic field present in the plane of deformation of a thin infinite conducting plate with a circular hole, the plate being deformed by a tension acting parallel to the direction of the magnetic field.
Heat transfer in a laminar cyclone I
Authors: Millsaps K. , Nydahl J. E.
Published: June 2007

A mathematical analysis of the partial differential system that describes the combined heat transfer in a laminally rotating fluid over the fixed ground, the Bödewadt problem, is presented by a reduction to an ordinary differential system by using a set of similarity transformations, that is a generalization of previously used ones due to von Kármán, Bödewadt, Millsaps and Pohlhausen, and Luk, Millsaps and Pohlhausen. For the case of forced convection the tabulated results of numerical integrations for the functions that occur in the set of similarity transformations are given, and comparisons are made with other results on the hydrodynamics that have been given by previous investigators.
Sukzessive Approximationen zur Berechnung der Überschallströmung um Flügel mit Unterschall‐Vorderkanten
Authors: Leiter E.
Published: June 2007

Für das räumliche Problem der tragenden Fläche mit zwei Unterschall‐Vorderkanten im stationären Überschallflug — im Rahmen der linearen (akustischen) Theorie — wird eine Integro‐Differentialgleichung von der Form einer Fixpunktgleichung [12] gegeben. Vorausgesetzt sind genügend kleine Anstellwinkel und somit Anliegen der Strömung an den Vorderkanten. Mit der Wölbungsverteilung der Skelettfläche (Prandtlsche zweite Hauptaufgabe der Tragflügeltheorie) folgen schrittweise Approximationen der Auftriebs‐ wie auch der Aufwindverteilung. Die Näherungen von J. C. Evvard sowie von Etkin und Woodward erweisen sich als geeignete Ausgangsapproximationen.

Für die (ebene) Dreiecksplatte, die alle wesentlichen Eigenschaften des in Frage stehenden Strömungstyps aufweist, werden die zweite Approximation der Auftriebsverteilung und deren relative Abweichung von der exakten Lösung gerechnet. Diese und die nachfolgende Fehlerobschätzung auch der höheren Approximationen zeigen, abgesehen von Flügeln extrem kleiner Streckung, die rasche Konvergenz des Verfahrens.
Elastic‐plastic materials as simple materials
Authors: Holsapple K. A.
Published: June 2007

A theory including classical elastic‐plastic materials is derived as a special case of the theory of simple material under certain hypotheses of smoothness and rate‐independence. The concepts of yield functions and flow rules of the classical theories are shown to be defined by the stress functional of a simple material under these smoothness hypotheses. A classical strain‐hardening elastic‐plastic material is included as an example.
On the Bending of the Web in a Wheel Subjected to a Single Concentrated Lateral, Load on the Rim
Authors: Rao A. Ramamohana , Narayanamurthi R. G.
Published: June 2007

In this paper, analytical treatment for determining the stresses and deflections in a rimmed wheel having a straight single web of constant rigidity, subjected to a single concentrated load on the rim parallel to the wheel axis, has been presented. With the equations established, the influence of each of the factors affecting the stresses and deflections has been studied.
Heat Transfer in the Plane Couette Flow of a Non‐Newtonian Fluid with Uniform Suction at the Stationary Wall
Authors: Bhatnagar R. K.
Published: June 2007

The paper deals with the discussion of heat transfer phenomenon in the steady flow of a Rivlin‐Ericksen Fluid confined between two plane parallel walls, one of which moves with a constant velocity while the other is held at the rest with a uniform suction applied on it. The solution of the energy equation is provided for the case in which both the walls are maintained at constant temperature, treating the suction parameter to be small. In the presence of suction the temperature distribution for the fluid under consideration differs from that for a classical viscous fluid only when the product of Prandtl and Eckert numbers is non‐zero. The presence of visco‐elasticity results in increasing the temperature in comparison to that for a Newtonian fluid. However, it also increases as the suction parameter increases. Many other interesting results are reported.
Linear Equations with an Operator Polynomial on the Left Side
Authors: Bittner L.
Published: June 2007

By means of Hermite's interpolation formula the identity map is represented as a sum of certain factors occuring in the operator polynomial of the equation under debate. Thus the solution of the given equation is reduced to so called simple equations. Solvability relations between the original and the corresponding simple equations are derived. The effectivity of the method is illustrated by applications to traditional topics of operational calculus, differential and difference equations with constant coefficients, and moreover, to linear algebraic and Fredholmian integral equations.
A New Type of Burgers' Equation
Authors: Nariboli G. A. , Lin W. C.
Published: June 2007

Assuming a similarity hypothesis that achieves the balance of non‐linearity, unsteadiness and dissipative effects, a new type of Burgers' equation is obtained. Consideration is limited to those cases where the singular surface theory predicts no growth of acceleration wave. Two examples are given. In these examples the interpretation of the evolutionary character of shock formation from acceleration waves for a non‐dissipative system fails. The present work provides such an interpretation. Taylor's solution for a plane shock and self‐similar solutions for plane and cylindrical shocks are discussed.
Diffraction of a Flexural Wave by an Inner Circular Boundary in an Unbounded Flat Plate
Authors: Culkowski P. M. , Reismann H.
Published: June 2007

This paper presents an exact solution of the diffraction of a flexural wave by an inner circular cut‐out in an unbounded, flat plate. The wave is generated by the harmonic oscillation of an arbitrarily positioned, concentrated transverse load. Both free and clamped boundary conditions are considered. The analysis is carried out within the framework of an improved plate theory which accounts for the effects of shear deformation and rotatory inertia. The results so obtained are compared to the corresponding solution using classical plate theory.
Unsymmetrische gleichmäßige Approximation
Authors: Krabs W.
Published: June 2007

Es geht um das Problem, eine vorgegebene Funktion f aus dem Vektorraum C(B) der reellwertigen stetigen Funktionen auf einem kompakten metrischen Raum B im Sinne einer passenden unsymmetrischen Norm möglichst gut zu approximieren durch Funktionen aus einer vorgegebenen nichtleeren Teilmenge W von C(B).

Zunächst wird die Beziehung dieses Problems zu dem Problem der besten gleichmäßigen Approximation von f durch Funktionen aus W (im Sinne der Maximum‐Norm in C(B)) untersucht. Sodann werden Einschließungssätze für die (unsymmetrische) Minimalabweichung und notwendige und hinreichende Bedingungen für beste Approximierende hergeleitet.

Schließlich wird noch der Fall der linearen unsymmetrischen gleichmäßigen Approximation behandelt.
Zur Verteilung der Mantisse in der Gleitkommadarstellung einer Zufallsgröße
Authors: Schatte P.
Published: June 2007

Die Verteilung der Mantisse einer Zufallsgröße wird untersucht. Nach der Betrachtung elementarer Eigenschaften wird die Entwicklung in eine Fourierreihe hergeleitet. Durch Benutzung dieser Entwicklung kann unter sehr allgemeinen Voraussetzungen gezeigt werden, daß die Mantissenverteilung eines Produktes identisch verteilter unabhängiger Zufallsgrößen mit wachsender Faktorenzahl gegenlog xstrebt. Eine entsprechende Aussage kann für Summen von Zufallsgrößen hergeleitet werden, wenn mit dem H∞‐Verfahren limitiert wird. Es wird die Hypothese aufgestellt, daß nach genügend langer Rechnung die auftretenden Mantissen logarithmisch verteilt sind. Die Hypothese wird empirisch überprüft, Anwendungsmöglichkeiten werden skizziert.
Behandlung eines Goursatproblems mit einer verallgemeinerten Riemannschen Methode
Authors: Mülthei H. N.
Published: June 2007

In dieser Arbeit wird ein lineares Goursat problem in zwei Zeit‐ und einer Raumvariablen behandelt. Die Koeffizienten der betrachteten Differentialgleichung müssen hierbei nach allen Variablen beliebig oft differenzierbar sein und nebst all ihren partiellen Ableitungen bestimmten Wachstumsbeschränkungen genügen. Für die Inhomogenität und die Vorgaben werden gesonderte Voraussetzungen gestellt. Zuerst wird für ein hinsichtlich der Anfangsbedingungen verallgemeinertes Goursatproblem die eindeutige Lösbarkeit in der gleichen Funktionenklasse bewiesen, in der die Koeffizienten der Differentialgleichung liegen. Auf Grund dieses Ergebnisses gelingt es dann, mit Hilfe einer verallgemeinerten Riemannschen Integrationsmethode allgemeinere Existenz‐ und Eindeutigkeitsaussagen für das anfangs erwähnte Goursatproblem zu gewinnen. Die Hauptschwierigkeit besteht hierbei in der Bestimmung einer verallgemeinerten Riemannschen Funktion.
Zur Abschätzung der Frequenz nichtlinearer Schwingungen einer Klasse gewöhnlicher Differentialgleichungen
Authors: Schneider K. R.
Published: June 2007

Es wird eine obere Schranke für die Frequenz einer beliebigen periodischen Lösung der nichtlinearen Differentialgleichung d(m)x/dtm + r1 d(m−1)x/dtm−1 + … + rm−1 dx/dt = f(x) unter der Voraussetzung abgeleitet, daß ∣f′(x)∣ M für — ∞ < × < + ∞ gilt. Die erhaltene Schranke, die unter Verwendung des Stetigkeitsmoduls der Funktion f(x) abgeleitet wurde, stellt eine Funktion der Koeffizienten ri und der Konstante M dar.
Kinematical Drift of two Degree of Freedom Gyroscopes
Authors: Willems P. Y. , Nishikawa Y.
Published: June 2007

Es wird das Verhalten von Kreiseln mit zwei Freiheitsgraden untersucht, die einer monofrequenten Schwingung unterworfen sind. Mit Hilfe einer Methode, die sich für die Untersuchung der Stabilität schwach nichtlinearer dynamischer Systeme eignet, werden nichtlineare und parametrische Resonanzen analysiert. Es werden Stabilitätsbedingungen angegeben, die die physikalischen Parameter des Systems enthalten.
Forced Motion of Cylindrical Shells — A Comparison of Shell Theory with Elasticity Theory
Authors: Weingarten L. I. , Reismann H.
Published: June 2007

Die dynamische Reaktion einer frei gelagerten kreiszylindrischen Schale wird im Rahmen der dreidimensionalen Elastizitätstheorie behandelt. Für eine spezielle Lastverteilung und Schalengeometrie wird die so gewonnene Lösung mit derjenigen, die man im Rahmen der Flüggeschen und der „verbesserten”︁ Schalentheorie erhält, numerische verglichen. Es zeigt sich, daß — gemessen an der elastizitätstheoretischen Lösung — die „verbesserte”︁ Theorie hinsichtlich der Voraussage des Reaktionsverhaltens der Schale über Zeiten, die die Spannungs‐ und Verschiebungs‐maxima enthalten, bessere Ergebnisse liefert als die Flüggesche Theorie und daß außerdem Vorsicht am Platze ist, wenn eine der Schalentheorien auf das anfängliche Reaktionsverhalten angewendet wird.
Stresses and Displacements under a Flexible Circular Foundation in the Presence of Friction or Adhesion
Authors: Nayak M. , Srinivasan R. J.
Published: June 2007

Die Vorliegende Arbeit beschäftigt sich mit den Spannungen und Verschiebungen an einem elastischen Halbraum unter einem kreisförmigen biegsamen Fundament, wenn an der Kontaktfläche vollkommenes Haften besteht. Das gemischte Randwertproblem wird mit Hilfe von Hankel‐Transformationen auf duale Integralgleichungen von Titchmarsh‐ Typ zurückgeführt. Für die Berechnung der Spannungen und Verschiebungen werden Gaußsche Quadraturformeln benutzt. Die Ergebnisse werden mit denen verglichen, die man bei glattem Fundament erhält, und der Einfluß der Poisson‐Zahl auf die Spannungen und Verschiebungen wird deutlich gemacht. Schließlich werden die Ergebnisse für den praktischen Gebrauch in Diagrammen und Tabellen zusammengefaßt.
Über Simultanverfahren zur Bestimmung reeller Polynomwurzeln
Authors: Alefeld G. , Herzberger J.
Published: June 2007

In dieser Arbeit werden zwei Verfahren — ein Gesamtschritt‐ und ein Einzelschrittverfahren — zur simultanen Bestimmung von reellen Polynomwurzeln angegeben. Besitzt das Polynom reelle einfache Wurzeln, so sind beide Verfahren stets konvergent, falls die Nullstellen in disjunkte Intervalle eingeschlossen sind. Das Gesamtschrittverfahren konvergiert mindestens quadratisch. Bezeichnet σn < 1 die einzige positive Nullstelle des Polynoms p(μ) = μn − μ − 1, so konvergiert das Einzelschrittverfahren mindestens von der Ordnung 1 + σn < 2.
Homogeneous Solution of Elastic Wave Propagation in the Presence of a Half‐Plane at the Fluid‐Solid Interface
Authors: Ghosh M. L.
Published: June 2007

Im Anschluß an eine Vorgehensweise von Miles wird für das Problem der Beugung eines durch eine ebene, starre, glatte Wand hervorgerufenen Impulses an der Trennfläche zwischen einem halbunendlichen elastischen festen Körper und einem halbunendlichen flüssigen Medium die homogene Lösung abgeleitet. Die Bewegungsgleichungen werden entweder auf die zweidimensionale Laplace‐Gleichung oder auf die eindimensionale Wellengeleichung zurückgeführt, die Lösungen auf funktionentheoretischen Wege bzw. mittels der Charakteristikentheorie gewonnen. Die Komponenten der Verschiebungen sowohl an den Wellenfronten als auch in den einfachen Wellenzonen werden in geschlossener Form angegeben.
On Lifting Wings with Parabolic Tips
Authors: Jordan P. F.
Published: June 2007

Eine Klasse noch ungelöster Probleme der Potentialtheorie sind die Drucksingularitäten, die an den Flügelenden tragender Flächen entstehen. In dieser Arbeit wird die Singularität an Flügelenden parabolischer Form dadurch bestimmt, daß das Problem des Kreisflügels ohne Wölbung in inkompressibler Strömung gelöst wird. In diesem Spezialfalle ist eine analytischen Untersuchung möglich, und eine bequeme Formulierung ist bereits vorhanden. Die Untersuchung zeigt zum Beispiel, daß eine elliptische Auftriebverteilung nicht durch einen endlichen Abwind am Flügel erzeugt werden kann. Nämlich, eine bestimmte (recht interessante) Endsingularität, die logarithmische Komponenten enthält, ist in jeder technisch sinnvollen Druckverteilung enthalten; die gleiche Singularität tritt auf an allen parabolischen Flügelenden im Unterschallbereich. Da diese Singularität abgespalten werden kann, können numerische Lösungen, zum mindesten für den Kreisflügel, leicht mit hoher Genauigkeit berechnet und in recht kurzen Tafeln reproduziert werden.