bluuebunny/crossref_metadata_2025 huggingface dataset:
Glass transition temperature of allyl methacrylate‐n‐butyl acrylate gradient copolymers in dependence on chemical composition and molecular weight
Authors: París Rodrigo , De la Fuente José Luis
Published: June 2007

Glass transition temperatures (Tgs) of P(AMA‐co‐BA) copolymers and the corresponding homopolymers, where AMA is allyl methacrylate and BA isn‐butyl acrylate, obtained by means of atom transfer radical polymerization were measured using differential scanning calorimetry. Because of the (pseudoliving) nature of this polymerization technique an increase in molecular weight (MW) is produced as the reaction progresses, which gives rise to an increase inTgs. This increment can be adequately described by the Fox–Flory's equation in both homopolymers. However, in the spontaneous gradient copolymers of P(AMA‐co‐BA), the expected increase inTgwith the augment of the monomer conversion is compensated by the enrichment of BA as the polymerization reaction progresses. These opposite effects with respect to theTgvalues almost balance each other, and therefore no significant influence on the MW or on conversion is found. This fact establishes thatTgs can be used to describe the profile of these gradient copolymers, and can be theoretically determined because of its dependence on the molar fraction in the copolymer. From this dependence on chemical composition along with the experimental behavior, a prediction of theTgvariation with the MW was performed. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1845–1855, 2007
Effect of a sorbitol nucleating agent on fractionated crystallization of polypropylene droplets
Authors: Jin Y. , Hiltner A. , Baer E.
Published: June 2007

The effect of a sorbitol nucleating agent on crystallization of polypropylene (PP) in droplets was studied. Layer‐multiplying coextrusion was used to fabricate assemblies of 257 layers, in which PP nanolayers alternated with thicker polystyrene (PS) layers. The concentration of a commercial nucleating agent, Millad 3988 (MD) in the layers was varied up to 2 wt %. When the assembly was heated into the melt, interfacial driven breakup of the 12 nm PP layers produced a dispersion of submicron PP particles in a PS matrix. Analysis of optical microscope images and atomic force microscope images indicated that the particle size was not affected by the presence of MD. The crystallization behavior of the particle dispersion was characterized by thermal analysis. In the absence of a nucleating agent, the submicron particles crystallized almost exclusively by homogeneous nucleation at about 40 °C. Addition of a nucleating agent to the PP layers offered a unique opportunity to study the nature of heterogeneous nucleation. Nucleation by MD resulted in fractionated crystallization of the submicron PP particles. The concentration dependence of the multiple crystallization exotherms was interpreted in terms of the binary polypropylene‐sorbitol phase diagram. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1788–1797, 2007
Planning for a solid waste management quality assurance program in Egypt
Authors: Abdel Rahman R. O. , El‐Kamash A. M. , Shehata F. A. , El‐Sourougy M. R.
Published: June 2007

Over the past 40 years, a considerable amount of solid radioactive waste has been generated in Egypt from a variety of nuclear technology applications in research, medicine, and industry. The Hot Laboratory and Waste Management Center at Inshas, Cairo, has started to build an integrated waste management system to ensure the safe management of this radioactive waste. During the establishment of this system, a range of technological options have been identified and evaluated in order to select and justify the most appropriate option for each waste type, taking into account the basic waste management principles, regulatory requirements, available resources, and other technical and non‐technical factors. Unfortunately, some of the generated wastes were not under a Quality Assurance Program that provides maintenance of traceability to production or conditioning records. So, these wastes are considered unacceptable to be placed in the disposal facility and need to be characterized and brought to an acceptable condition prior to disposal. This must be done in accordance with comprehensive plans and documented procedures to guarantee the safe handling, storage, and disposal. In this work, the existing Egyptian solid waste management system will be presented with a special reference to a management plan to be applied through this system. This will include a description of the organizational structure, functional responsibilities, organizational interfaces, personnel training, documentation, and corrective action. Copyright © 2007 John Wiley & Sons, Ltd.
Problems in DFT with the total spin and degenerate states
Authors: Kaplan I. G.
Published: June 2007

The problems arising in the density functional theory when it is applied to the spin‐ and space‐degenerate states are discussed. It is rigorously proved that in the case of orthonormal orbital set, the electron density of an arbitrary N‐electron system does not depend upon the total spin S and for all values of S has the same form as it has for a single‐determinantal wave function. From this follows that the conventional Kohn–Sham equations cannot distinguish the states with different total spin values. A critical survey of the existing DFT methods of taking into account the total spin is performed. It is shown that all these methods, including state‐ and orbital‐dependent functional method, modify only the expression for the exchange energy and use the correlation functionals not corresponding to the total spin of the state. It is also proved that the diagonal element of the density matrix is invariant with respect to the symmetry of the state, hence in this respect there is no difference between degenerate and nondegenerate states. On the other hand, for the degenerate states, the Born–Oppenheimer approximation fails, so that makes it impossible to apply the density functional formalism. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Novel monoclonal antibodies for the investigation of PCH family proteins
Authors: Lettau Marcus , Beyer Alyn , Janssen Ottmar
Published: June 2007

The pombe Cdc15 homology (PCH) protein family (also termed FCH/SH3 family) comprises 5 subgroups of structurally related polypeptides. The protein kinase C and casein kinase substrate in neurons 1 (PACSIN1), the CD2‐binding protein 1 (CD2BP1) and the Cdc42‐interacting protein 4 (CIP4) represent members of three individual subgroups. PCH proteins in general are supposed to link cytoskeletal elements to membrane trafficking machineries. In various cellular systems, PCH proteins are involved in lysosomal targeting, vesicular transport, and endocytotic as well as exocytotic processes. However, the specific molecular networks around individual PCH proteins and their localization in different cell populations need to be identified. We have recently reported that several members of the PCH family interact with the death factor FasL (CD178). This interaction is mediated via the SH3 domains of PCH proteins binding to the proline‐rich cytoplasmatic region of FasL. To analyze the role of endogenous PCH proteins in the context of FasL or other interactors, novel molecular tools are needed. We developed a set of monoclonal antibodies against three individual PCH family members. These novel reagents will help to analyze the presence and function of endogenous PCH proteins in lymphocytes and other cell types.
Diagrid structural systems for tall buildings: characteristics and methodology for preliminary design
Authors: Moon Kyoung‐Sun , Connor Jerome J. , Fernandez John E.
Published: June 2007

Diagrid structural systems are emerging as structurally efficient as well as architecturally significant assemblies for tall buildings. This paper presents a simple methodology for determining preliminary member sizes. The methodology is applied to a set of building heights ranging from 20 to 60 stories, and parameters for the optimal values of the grid geometry are generated for representative design loadings. These values are shown to be useful for architects and engineers as guidelines for preliminary design. Associated architectural and constructability issues of diagrid structures are also discussed here. Copyright © 2007 John Wiley & Sons, Ltd.
Stabilitätsaussagen für einige Aufgaben mit freier Grenze
Authors: Gajewski H.
Published: June 2007

Im Rahmen der Theorie maximal monotoner Operatoren werden Stabilitätsabschätzungen für einige Variationsungleichungen angegeben. Als Beispiele werden geradlinige Rohrströmungen viskoplastischer Medien und das Stefansche Problem betrachtet.
Über ein bemerkenswertes Verhalten der Spannungen in der ebenen Elastizitätstheorie
Authors: Maul J.
Published: June 2007

In der Arbeit wird ein speziellesPoincaréproblem der ebenen Elastizitätstheorie untersucht, bei dem der Spannungs‐ tensor in tangentieller Richtung auf dem Rand vorgegeben wird. Unter Verwendung vonMuschelišvilischenMethoden wird dieses Problem für solche Gebiete gelöst, auf die der Einheitskreis durch eine rationale Funktion konform abbildbar ist. Im Falle eines Kreises wird die Eindeutigkeit der Spannungen bewiesen, und die Lösbarkeitsbedingungen werden berechnet. Am Beispiel einer speziellen verkürzten Epizykloide wird gezeigt, daß die Spannungen durch die Randwerte der Aufgabe im allgemeinen nicht eindeutig bestimmt werden.
Creep Stresses in a Hollow Sphere with Stamps on the External Surface
Authors: Hata T.
Published: June 2007

This paper is concerned with a method for calculating the stress distribution in a sphere which undergoes elastic and creep deformation due to the axisymmetric loading. Applying the Goodier's concept to the inelastic problem and adopting the procedure of a step by step progression in time, the solution of the incremental creep strain problem reduces to the particular and the complementary ones. Using the foregoing method, the solution is derived for calculating the creep stresses in a hollow sphere with stamps on the external surface. The numerical results show how the stress distribution varies with time through creep.
Non‐Equilibrium Flow of an Inviscid Gas past a Thin Profile
Authors: Homentcovschi D.
Published: June 2007

This paper considers the steady and linearized motion of a non‐equilibrium inviscid gas past a thin profile. The form in distributions of the equations of the aerodynamics is used. For the symmetrical profile the problem is completely solved. For the case of the profile without thickness the problem calls for a separate consideration of the completely subsonic, intermediate and completely supersonic regimes respectively. In the first two cases the determination of the function n(x) reduces to the resolution of a Fredholm type regular integral equation of the second species. The paper gives the asymptotic solution of the problem for high values of τ0. For the case of the completely supersonic regime the problem is solved to the end. The motion of a fluid over a wall is also analysed.
A Class of Nonlinear Nondifferentiable Complex Programming
Authors: Das C. , Swarup K.
Published: June 2007

A nonlinear, possibly nondifferentiable, complex program and its dual program are given. The nonlinearity appears in the form of quadratic forms and square roots of such forms. The nondifferentiability results from these square roots. Appropriate duality theorems, generalizing earlier results are established.
Zur approximativen Lösung des Mittelungsproblems für die Eigenwerte stochastischer Differentialoperatoren
Authors: Purkert Walter , Vom Scheidt Jürgen
Published: June 2007

Es wird ein stochastisches Eigenwertproblemmagnified imagemit den Randbedingungenmagnified image= 0 betrachtet.

Die Eigenwerte λv(ω) sind dann Zufallsgrößen. Ersetzt man im Ausgangsproblem die stochastischen Größen ai(x, ω) durch ihre Erwartungswerte 〈ai(χ)〉, so entsteht das sogenannte gemittelte Problemmagnified image, (gleiche Randbedingungen); dessen Eigenwerte seien μv. Es werden unter 2. für den Fall selbstadjungierter Operatoren Formeln angegeben, die den Vergleich von 〈λy〉, und μvgestatten. Ferner werden die Korrelationskoeffizienten und Varianzen der λv(ω) näherungsweise berechnet. Unter 3. werden ähnliche Resultate für den Fall nichtsymmetrischer zufälliger Störungen erhalten. In 4. erfolgen Anwendungen auf die eindimensionaleSchrödinger‐Gleichung mit zufälligem Potential sowie auf das Problem kleiner transversaler Schwingungen eines elastischen Trägers bei zufälligen Schwankungen der Querschnittsfläche und des Trägheitsmoments.
Eine dyadische Infinitesimalrechnung für Haar‐Funktionen
Authors: Splettstösser W. , Wagner H. J.
Published: June 2007

Die bekanntesten Orthogonalsysteme, die aus Stufenfunktionen bestehen, sind dasWalsh‐ und dasHaar‐System. Diese sind eng miteinander verwandt, lassen sich leicht über die binäre Darstellung reeller Zahlen definieren und mit wenigen logischen Schaltelementen technisch realisieren. Es wird daher eine dyadische Infinitesimalrechnung aufgebaut, die genau demHaar‐System angepaßt ist im Gegensatz zurLeibniz‐Newtonschen Infinitesimalrechnung. Dies erlaubt unter anderem neue Fehlerabschätzungen beiFourier‐Haar‐Reihen und bei der Approximation durchHaar‐Polynome. Ferner wird die hier angewandteHaarsche Infinitesimalrechnung mit demWalsh‐Kalkül verglichen.
Moving Harmonic Load on an Elastically Supported Timoshenko Beam
Authors: Chonan S.
Published: June 2007

An analysis is made of the problem of vibrations of a beam on elastic foundation, when the beam is of infinite length and is subjected to an alternating load which moves with constant velocity along the beam. The solution is presented within the framework of a beam theory which includes the effects of shear deformation and rotary inertia. Critical characteristic parameters of the system are defined. An example is provided where the displacement and the bending moment are calculated. From the results of theoretical analysis, it becomes evident that the frequency of the load has considerable effect upon the dynamical behaviour of the system.
Dissoziation in Strömungen mit starken Abweichungen vom Gleichgewicht
Authors: Peller H. , Hindelang F. J.
Published: June 2007

Ziel der Untersuchung ist, den Verlauf der Strömungsgrößen und den Grad der Dissoziation in starken Stoßwellen (Ma > 25) durch zweiatomige Gase zu bestimmen. Dabei wird angenommen, daß wegen der besonders energiereichen Teilchenstöße Moleküle aus dem Grundzustand der Vibration dissoziieren können, bevor Translationsgleichgewicht erreicht ist. Außerdem soll die Verteilungsfunktion aus einer Linearkombination der Gleichgewichtsverteilungen vor und nach der Stoßfront bestehen. Um das Problem beschreiben zu können, benötigt man neben den Erhaltungsgleichungen eine höhere Momentengleichung. Um den Einfluß des Exponenten der Moleküleigenschaft abschätzen zu können, werden verschiedene Momentengleichungen aufgestellt. Zur Beschreibung der chemischen Prozesse in der Stoßfront ist eine zusätzliche Gleichung erforderlich. Die darin auftretenden Ratenkonstanten wurden aus gemessenen Werten für den sehr hohen Temperaturbereich am Ende der Stoßfront extrapoliert. Gleichzeitig wurde aus theoretischen Überlegungen ein statistischer Ratenkoeffizient abgeleitet, welcher die verschiedenen Temperaturen der stoßenden Teilchen berücksichtigt. Das nichtlineare Differentialgleichungssystem wird numerisch integriert. Dabei wird ein implizites Verfahren verwendet, welches bei vertretbarer Rechenzeit genügend Genauigkeit ergibt. Die Ergebnisse stimmen mit dem erwarteten Verlauf der Strömungsgrößen und dem Dissoziationsgrad überein. Es zeigt sich, daß bei Verwendung der theoretischen Ratenkonstante bei der Machzahl Ma = 50 alle Moleküle am Ende der Stoßfront dissoziiert sind. Neben diesen Ergebnissen wird der Einfluß der Moleküleigenschaft auf die Strömungsgrößen diskutiert.
Zur Konvergenzrate von Verfahren mit konjugierten Gradienten ohne exakte Strahlminimierung
Authors: Lippold Günter
Published: June 2007

In verschiedenen Arbeiten wurde gezeigt, daß spezielle Verfahren der konjugierten Gradienten für stark konvexe Funktionen mit Lipschitz‐stetigen zweiten Ableitungen n‐quadratisch konvergieren, wenn in jedem Schritt eine exakte Strahlminimierung ausgeführt wird. Wir beweisen, daß es für eine Modifikation des Verfahrens von Fletcher und Reeves genügt, in jedem Schritt den Minimalpunkt der Funktion auf dem Strahl mit quadratischer Ordnung zu approximieren, wofür unter den genannten Voraussetzungen lokal nicht mehr als 3 Funktionsaufrufe je Schritt benötigt werden.
Existence Theory for Symmetric Dual Nonlinear Programs in Complex Space
Authors: Parida J. , Sahoo B.
Published: June 2007

In this paper, an existence and uniqueness theorem for a pair of complex nonlinear, symmetric, dual programs over polyhedral cones is established, using the theory of the nonlinear complementarity problem in complex space.
Spezielle Nockengetriebe und geometrische Eigenschaften dazu verwandter Kurven
Authors: Hoschek J.
Published: June 2007

Soll bei Kurvenscheiben Zwanglauf über Doppelkurven erreicht werden, so haben Kurve und Gegenkurve im allgemeinen verschiedene Gestalt. In der vorliegenden Untersuchung wird gefragt, bei welchen Bewegungsgesetzen beim Doppelstößel Kurve und Gegenkurve gleiche Gestalt besitzen. Die gefundenen Kurven lassen sich als Verallgemeinerungen der bekannten Kurven konstanter Breite deuten, eine kinematische Erzeugung führt auf Verallgemeinerungen der Zindler‐Kurven.
Zur Struktur‐Rheologie der Sehnenmechanik
Authors: Zech M. , Hartung C.
Published: June 2007

Sehnen übertragen vorwiegend Zugkräfte von den Muskeln auf das Skelett und enthalten besonders kollagenes Gewebe. Sein komplexes biomechanisches Verhalten kann in einem diskreten nichtlinear‐viskoelastischen Modell erfaßt werden, das auch mikroskopische Vorgänge berücksichtigt, die sich bei Be‐ und Entlastung in der Sehne abspielen. So lassen sich Zusammenhänge zwischen makroskopischer Sehnenmechanik und entsprechenden Phänomenen in der Mikrostruktur der Sehne mathematisch angeben. Durch Anpassung des Modells an eigene experimentelle Untersuchungen, die mit elektronischen Zugprüfmaschinen durchgeführt wurden, werden die zugehörigen Material‐Kenngrößen ermittelt. Derartige Untersuchungen sind notwendig, wenn Rückschlüsse aus dem histologischen Präparat auf das mechanische Verhalten der Sehne in vivo gezogen werden sollen, und grundsätzlich nötig, um kompliziertere Vorgänge des Bewegungsapparates zu simulieren, bzw. mechanisch kompatiblere Implantatsmaterialien zu entwickeln.
Saint‐Venant's Problem for Inhomogeneous and Anisotropic Cosserat Elastic Solids
Authors: Ieşan D.
Published: June 2007

The present paper is concerned with Saint‐Venant's problem for inhomogeneous and anisotropic cylinder in the linear theory of Cosserat elasticity. The elastic coefficients are independent of the axial coordinate. The problem is solved using four generalized plane strain problems.
The Transmission of Force through a Fluid‐Solid Interface
Authors: Aderogba K. , Adeboye E. A.
Published: June 2007

Consideration is given to a fluid‐solid system consisting of a semi‐infinite incompressible viscous fluid overlying an isotropic semi‐infinite elastic solid. A uniform force is operative within a subregion of the fluid or the solid. It is shown within the limits of the linear theories of elasticity and hydrodynamics that the fields in the two phases may be easily expressed in terms of the corresponding fields in the homogeneous infinite media. In particular, the interface value of the displacement of the solid due to a force operative in the overlying fluid depends on both the velocity and pressure fields of the same force in an infinite fluid, the former proportionally, and the latter through integration. In contrast, the associated interface traction is always proportional to the infinite‐fluid result, regardless of the geometry of the region of application of the force, and for any force distribution. This multiplicative property can however be shown to exhibit itself in the displacement field also, provided that the infinite‐fluid velocity is derivable by differentiation from a harmonic potential. A uniformity of method is maintained by initially representing the solutions for both the fluid and the solid in terms of Papkovitch‐Neuber functions, which are known to be superior to other stress functions, because of their completeness and harmonicity.
Standby Redundant Systems in Random Environment
Authors: Råde Lennart
Published: June 2007

Reliability systems with one or two redundant standby components are studied. The systems are situated in a random environment which generates shocks according to a renewal point process. The shocks will cause a component to fail with a certain probability. Failed components are immediately repaired and the repair times are exponentially distributed. Special consideration is given to systems with cold and with warm standby components. Numerical studies are made of the effect of standby and of repair when shocks are generated by a Poisson process.
On a System of p‐Tuple Series Equations Related to the Scattering by an Inhomogeneous Sphere
Authors: Idemen Mithat
Published: June 2007

A system of p‐tuple series equations, involving associate Legendre functions, related to the scattering of electromagnetic waves by a spherical surface divided into p parallel strips with different impedances is studied. The original problem of solving a system composed of two p‐tuple series equations is reduced to a problem of solving 2(2p—1) (or two) completely independent p‐tuple series equations with the same kernel as well as a system of linear algebraic equations. The solutions to the independent series equations can be found by successive iterations. The conditions wich guarantee the convergence of the iterations and the uniqueness of the solution are given in two theorems. The results are applied to a simple illustrative example.
Numerische Faktorisierung von Polynomen
Authors: Berg L.
Published: June 2007

Nach F. L. Bauer [1] kann der für die Auflösung linearer Gleichungssysteme bekannte Gaußsche Algorithmus auch zur Zerlegung von Polynomen in zwei Faktorpolynome herangezogen werden. Im folgenden soll hierfür ein neuer Konvergenzbeweis gegeben werden, wobei die Voraussetzungen etwas abgeschwächt werden.
Zum Maximum‐Prinzip von Pontrjagin für eine Klasse partieller Differentialgleichungssysteme 1. Ordnung
Authors: Wolfersdorf L. V.
Published: June 2007

Es wird ein Analogon zum Maximum‐Prinzip von Pontrjagin bei einer Klasse von optimalen Prozessen hergeleitet, die durch ein System von partiellen Differentialgleichungen 1. Ordnung und durch ein System von hyperbolischen partiellen Differentialgleichungen 2. Ordnung beschrieben werden.
Iterative Lösungen von Randwertproblemen partieller Differentialgleichungen vom zusammengesetzten Typ
Authors: Schincke E.
Published: June 2007

Die Arbeit enthält eine Methode zur numerischen Lösung gewisser Randwertprobleme für partielle Differentialgleichungen vom zusammengesetzten Typ. Nach Zurückführung des Ausgangsproblems auf eine komplexe Differentialgleichung wird die reguläre Lösung mittels einer entsprechenden Integralgleichung durch ein relativ einfaches Iterationsverfahren konstruiert. Um approximative Lösungen zu berechnen, ist eine verhältnismäßig geringe Anzahl von Iterationsschritten erforderlich, was an einem Testbeispiel gezeigt wird.
Qualitative Analysis of Interconnected Systems Described on Banach Spaces: Well Posedness, Instability and Lagrange Stability
Authors: Michel Anthony N. , Miller Richard K.
Published: June 2007

New qualitative results for interconnected dynamical systems described on Banach spaces are established. Items of interest include well posedness, instability, complete instability, and Lagrange stability (i.e., boundedness and ultimate boundedness of solutions). In all cases the objective is to analyze complex systems in terms of lower order subsystems and in terms of the system interconnecting structure. The results are applied to a specific hybrid dynamical system.
On Velocity Potentials and Stress Functions
Authors: Dost S. , Tabarrok B.
Published: June 2007

By using a variational principle which is complementary to Hamilton's Principle, and by introducing new stress functions, the domain of application of stress functions has been extended to problems of elastodynamics. The Euler‐Lagrange equations associated with the new stress functions emerge as additional compatibility conditions involving the velocity fields. It is shown how by Judicial choice of the new stress functions various restricted motions may be analysed.
Zur Erweiterung des Bruchkriteriums von Sih
Authors: Fischer K. F.
Published: June 2007

This paper deals with a formal extension of the Sih's fracture criterion so that the strain energy density factor is formulated both with the singular term and with the nonsingular terms of the solution in the elastic stress field near the crack tip. Thus, investigation of the direction of crack initiation leads to a two‐dimensional extreme value problem. In addition further statements on validity of the linear elastic behaviour of material in front of the crack tip are possible.
A Class of Nondifferentiable Fractional Programming Problems
Authors: Mond B.
Published: June 2007

Recently Chandra and Gulati established duality theorems for the nondifferentiable fractional programming problem maximize< [cTx – (xTBx)1/2 – α]/[eTx + (xTDx)1/2 + β] subject to Ax ≦ b, x≧. Here we treat the more general nonlinear fractional programming problem maximize [f(x) – (xT Bx)1/2]/[g(x) + (xT Dx)1/2] subject to h(x) ≦0, where f, g and h are differentiable, possibly nonlinear, functions. Necessary and sufficient conditions for optimality as well as appropriate duality theorems are established.
Existenz und Eindeutigkeit eines linearen hyperbolischen Anfangs‐Randwert‐problems und die praktische Anwendung auf Probleme aus der Hydraulik. Teil II: Die lineare hyperbolische Anfangs‐Randwertaufgabe auf Probleme aus der Hydraulik angewandt
Authors: Iben H. ‐K.
Published: June 2007

The quick closing action of a shut‐off valve arranged at the end of a line and the wave motion within the line of a Diesel injection system are treated as examples. In contrast to the conventional method, the desired injection law is given for the example of wave motion; the configuration of the value opening cross section is calculated.
The Effect of a Frictional Shear on Dynamic Stresses Produced in a Semi‐Infinite Solid by a Reciprocating Load
Authors: Ohyoshi Tadashi
Published: June 2007

Frictional forces, naturally generated at interfaces of solids, affect the distribution of dynamic stresses produced in a semiinfinite elastic solid by a reciprocally moving normal load prescribed on its boundary. Those mechanical characteristics are investigated by making use of the theoretical method of elastodynamics. Numerical calculation is carried out when the normal load is distributed harmonically in space and the frictional shear is determined by considering a coefficient of dynamic friction provided that the rule of the Coulomb friction is available. Numerical results are shown in graph and it is concluded that the effect on the stress distributions is comparatively large. Especially, arrivals of the shear shock waves from the friction surface cause abrupt transitions in the dynamic shear stress distribution, which phenomenon comes from the mechanical properties of reciprocation of the load moving on the friction surface.
Die Verfahren vom Brown‐Brent‐Typ bei gemischt linearen‐nichtlinearen Gleichungssystemen
Authors: Schmidt Jochen W. , Hoyer Wolfgang
Published: June 2007

It is shown that an appropriate adaptation of Brown‐Brent‐type algorithms to nonlinear systems involving a set of linear equations allows considerable saving of computational amount.
Konvergenz im Mittel von Phasensystemen
Authors: Koryakin Y. U. A. , Leonov G. A. , Reitmann V.
Published: June 2007

Continuous and discrete phase systems (i.e. non‐linear control systems, being periodical with respect to some coordinates) which play an important role as a theoretical basis in modern electronics, are investigated by means of frequency methods in this paper. Similar to the conception of convergence for ordinary differential equations phase convergence and α‐phase convergence in the mean are introduced for phase systems having the rank m. Sufficient conditions for the appearance of these types of convergence are given there. The results are applied to nonautonomous phase‐locked loops (PLL) with a proportional integrating filter and to discrete PLL with an integrating RC‐filter.
Solving the Generalized Transportation Problem with Constraints
Authors: Gupta Reeta
Published: June 2007

In the present paper a technique for solving generalized transportation problems with several extra linear constraints is developed. It is shown that it is not necessary to store and update the entire basis inverse at each iteration. The only informations needed at each iteration of the solution procedure consist in the storage of the disjoint basis components of the underlying generalized transportation problem and a q X q matrix (where q is the number of the additional constraints). A simple numerical example is given to illustrate the procedure.
On the Problem of a Generalization of the Hamilton‐Jacobi Method for Nonholonomic Systems
Authors: Rumyantsev V. V. , Sumbatov A. S.
Published: June 2007

The necessary and sufficient conditions of the applicability of the generalized Hamilton‐Jacobi method for integrating the equations of motion of mechanical systems with nonholonomic constraints of Chetaev's type are obtained. An example is considered.
Eine verallgemeinerte Darstellung inelastischer Deformationsgesetze zur Erleichterung der numerischen Lösung von Anfangs‐Randwertproblemen
Authors: Bergander H.
Published: June 2007

It is demonstrated that the connection between stress and strain can be presented in a united form for material classes of most various kinds. This form corresponds to a form of a linear elasticity law with additional strains for the increments of stress and strain. The coefficients of law depend on stress strain state and internal parameters. The number of parameters is differently great for various material states. This formulation is very advantageous for a numerical solution of boundary‐value problems with initial conditions of which are worked out the general aspects.
Optimal Design of Elastic Beams with Unspecified Support Conditions
Authors: Szeląg D. , Mróz Z.
Published: June 2007

Formulation of the problem of optimal design for beams with unspecified support position and stiffness is presented. It is assumed that the beam is composed of segments of unspecified cross‐sections and lengths which are to be determined together with support positions and cross‐sections. Design for specified mean compliance, first frequency of free vibrations or buckling force is considered and proper optimality criteria are derived. Illustrative examples are presented and the iterative algorithm of numerical solution is discussed in detail.
Error Bounds for the Liouville‐Green Approximation to Initial‐Value Problems
Authors: Taylor James G.
Published: June 2007

New error bounds are developed for the Liouville‐Green approximation for initial‐value problems governed by a single second‐order linear differential equation. The cases of both exponential‐type and also oscillatory solutions are considered. Previous error bounds are sharpened as a consequence of our development of these new error bounds for initial‐value problems. These new results are applied to an important class of linear differential equations arising in military operations research (specifically, variable‐coefficient Lanchester‐type equations of modern warfare for combat between two homogeneous forces).
Stefan Problems with Nonlinear Boundary Conditions: The Polygonal Method
Authors: Borgioli Giovanni , Benedetto Emmanuele Di , Ughi Maura
Published: June 2007

In this paper we present three applications of a polygonal method to the approximate solution of a one dimensional Stefan problem with nonlinear boundary conditions on the fixed face. Our results extend previous approaches which have appeared in literature. In the same time the regularity assumptions on the initial data are relaxed and great simplification is obtained in the proof arguments; moreover error estimates are performed in the general case.
Three Dimensional Unsteady Actuator Disk Theory for Subsonic Viscous Flow
Authors: Tsujimoto Y. , Murata S.
Published: June 2007

This paper gives an analysis of the viscous effects on the unsteady lifts acting on three‐dimensional subsonic cascades by means of actuator disk method. Rigorous solutions of linearized Navier‐Stokes equation are firstly given in the up‐and down‐stream regions of the actuator disk and then coupled together using the momentum equations and the equation of continuity. The results approach to the inviscid solutions so far known by letting Re → ∞. It is shown that the effects of the viscosity are remarkable especially near the resonance and at high frequency.
Stress Functions for Elastic Dielectrics
Authors: Glockner P. G. , Chowdhury K. L.
Published: June 2007

Beltrami‐type representations are constructed for the stress tensor, the polarization vector, and the electric tensor for Mindlin's theory of elastic dielectrics including polarization gradient effects. Using these representations and the linear compatibility conditions, stress boundary value problems of linear elastic dielectrics are formulated. This formulation is applied to one and two dimensional problems of dielectric half spaces and the results obtained therefrom are compared with corresponding solutions available in the literature [1,2].
On Simultaneous Torsion and Tension of a Circular Cylindrical Bar Consisting of an Elastoplastic Material with Linear Hardening
Authors: Hünlich R.
Published: June 2007

In the paper approximation methods for solution of initial boundary value problems of the theory of plasticity are described and demonstrated by a simple example.
A Linear Programming Formulation of the Problem of Moments
Authors: Siu W. W. C. , Sengupta S. S. , Lind N. C.
Published: June 2007

Solutions of the moment problem are sought in the class of density functions that possess certain conditions of continuity and differentiability. One can accomplish this by the methods of linear optimization if the nodal quantities, for instance, the ordinates and derivatives are retained as independent variables and if the density function is approximated over the subintervals by an interpolation process, such as the cubic spline functions. Computations indicate that the procedure yields bounds on the probabilities that are sharper than the ones due to the classical methods.
Stabilitätsberechnung dichtegeschichteter ebener Wandgrenzschichten
Authors: Strehle E.
Published: June 2007

Zur Berechnung der Stabilität dichtegeschichteter Grenzschichten werden die Differentialgleichungen hergeleitet. Ihre Integration geschieht nach einem rationellen numerischen Verfahren. Als wesentliches Ergebnis wird ein Stabilitätsdiagramm vorgelegt, aus dem man in Abhängigkeit von der thermischen Schichtung die kritische Reynoldszahl entnehmen kann. Hiermit läßt sich der zu erwartende Strömungszustand vorhersagen. Ein Vergleich mit experimentellen Ergebnissen zeigt gute Übereinstimmung.
Zur Existenz und Eindeutigkeit der Görtler‐Funktionen I. Die Eindeutigkeit
Authors: Schwierz K.‐P.
Published: June 2007

Gegeben sei die ebene und stationäre Strömung einer inkompressiblen und reibenden Flüssigkeit in einer laminaren Wandgrenzschicht. Zur Berechnung dieser Strömung wurde in [4], [5] und [11] die Görtler‐Reihe eingeführt. Die Koeffizienten‐funktionen dieser Reihe sind die Lösungen eines unendlichen Systems von gewöhnlichen Randwertaufgaben dritter Ordnung, die von unendlich vielen Strömungsparametern abhängen. Nach [16], [17] führt ein linearer Ansatz für die Koeffizientenfunktionen der Görtler‐Reihe auf ein zweifach unendliches System von Randwertaufgaben für die Ansatz‐funktionen. Diese Randwertaufgaben hängen nur noch von einem einzigen Strömungsparameter ab. Die Ansatzfunktionen sind in der Literatur unter dem Namen „Görtler‐Funktionen”︁ bekannt. — In dem vorliegenden Teil 1 soll die Eindeutigkeit dieser Görtler‐Funktionen nachgewiesen werden. Mit elementaren Mitteln wird dabei ein Widerspruchsbeweis geführt. In Teil II, der im folgenden Heft erscheinen wird, wird ein Existenzsatz bewiesen werden.
Second‐Order Stochastic Input‐Output Stability and Instability of Interconnected Systems
Authors: Gutmann R. L. , Michel A. N.
Published: June 2007

New results for the second‐order stochastic input‐output stability and instability of large classes of continuous time and discrete time interconnected stochastic systems are established. The analysis is accomplished in terms of lower order subsystems and in terms of system interconnecting structure. When appropriate, frequency domain interpretations are emphasized. The method of analysis advanced herein is applied to three specific examples.
Ein Grenzverteilungssatz für stochastische Eingenwertprobleme
Authors: Purkert W. , vom Scheidt J.
Published: June 2007

Es wird das stochastische Eigenwertproblembetrachtet. Die stochastischen Prozesse fr(x, ω) – 〈fr〉 seien unabhängig und schwach korreliert mit der Korrelationslänge ϵ. Es wird gezeigt, daß für die Eigenwerte und Eigenfunktionen bei ϵ → 0 ein zentraler Grenzwertsatz gilt. Die Parameter der Grenzverteilung werden berechnet. Sie hängen von den Eigenwerten μl und den Eigenfunktionen wl(x) des gemittelten Problemsab.
Verallgemeinerung eines Lemmas von J. L. Walsh nebst einigen Anwendungen
Authors: Boese G.
Published: June 2007

Ein vielfach von J. L. Walsh benutztes Lemma über den Funktionswert von Summen von Partialbrüchen wird in bezug auf die Polordnung der Partialbrüche verallgemeinert und dazu sind einige Anwendungen gegeben. Die Verallgemeinerung wird über die Untersuchung der Abbildungseigenschaften der Funktion w(z) = (1 – z)−s erhalten.
Plant‐scale operations for degumming, caustic‐refining, and water‐washing soybean oil by a two‐step continuous process
Authors: Kaiser H. R. , Hoffman C. A.
Published: June 2007

Operation of a four‐tank‐car‐per‐day plant, using a Duozon3 and a Hydrazon3 舠in series舡 to perform continuous degumming, caustic refining, and water washing of soybean oil is described. A simplified flow sheet, illustrating the process, and a detailed functional description of the degummer and the caustic refiner‐water washer are given. Typical plant‐operating data for this versatile, low‐cost plant are pressnted.
Four‐factor response surface optimization of the enzymatic modification of triolein to structured lipids
Authors: Shieh Chwen‐Jen , Akoh Casimir C. , Koehler Philip E.
Published: June 2007

The ability of an immobilized lipase to modify the fatty acid composition of (88.8% C18:1, 4.3% C16:0, 3.1% C18:0, and 3.8% C18:2 as determined by gas chromatography, and approximately 90% triolein) in hexane by incorporation of a medium‐chain fatty acid, capric acid (C10), to form structured triacylglycerol was studied. Response surface methodology was used to evaluate the effect of synthesis variables, such as reaction time (12–36 h), temperature (25–65°C), molar substrate ratio of capric acid to triolein (2:1–6:1), and enzyme amount (10–30% wt% of triacylglycerol), on the yield of structured lipid. Optimization of the transesterification was attempted to obtain maximum yield of structured lipid while using the minimum molar substrate ratio and enzyme amount as much as possible. Computer‐generated contour plot interpretation revealed that a relatively high molar substrate ratio (6:1) combined with low enzyme amount (10%) after 30 h of reaction at 25°C gave optimum incorporation of capric acid. A total yield for combined monoand dicaproolein of up to 100% was obtained.
Triglyceride deposition in tissues of germinating coconut (Cocos nucifera linn)
Authors: Balachandran C. , Arumughan C.
Published: June 2007

Coconut is the largest oilseed. In the present investigation, various lipid classes, such as triacylglycerol, free fatty acid, diacylglycerol, and their fatty acid compositions were determined from three regions of germinating coconut at three stages of germination. In this process, triacylglycerol was hydrolyzed and resynthesized in the haustorium tissue. Cooperative participation of various tissues, such as endosperm, haustorium, and embryo, was therefore involved in the process of germination of coconut.
Characterization of wax esters in the roe oil of amber fish,Seriola aureovittata
Authors: Joh Yong‐Goe , Brechany Elizabeth Y. , Christie William W.
Published: June 2007

The wax esters of the roe oil of the amber fish,Seriola aureovittata, have been resolved by high‐performance liquid chromatography (HPLC) in the silver‐ion mode. Each of the fractions collected was transmethylated, and the fatty acids and alcohols were identified by gas chromatography/mass spectrometry (GC/MS) as the picolinyl esters and nicotinates, respectively. Their compositions were determined by GC. The fatty acid composition is complex, and the main components are C18:1n‐9 (35.5 mol%), C22:6n‐3 (20.3 mol%), and C16:1n‐7 (10.7 mol%), while fatty alcohols are limited to saturated (C16:0, 60.3 mol%; C18:0, 15.3 mol%; C14:0, 5.1 mol%) and monoenoic alcohols (C18:1n‐9, 6.5 mol%; C16:1n‐7, 4.5 mol%) with traces (<0.1 mol%) of polyunsaturated fatty alcohols such as C20:3n‐3, C20:4n‐6, C20:5n‐3, and C22:5n‐3. Silver‐ion HPLC exhibited excellent resolution in which fractions were resolved on the basis of the number and configuration of double bonds as well as the distribution pattern between the acid and alcohol moieties of the molecules with a given number of double bonds. The main wax ester fraction are those of monoenoic acid‐saturated alcohol species, hexaenoic acid/saturated alcohol species, and pentaenoic acid/saturated alcohol species. Appreciable specificity was observed in the esterification of fatty acids with alcohols, and surprisingly, no saturated acid‐monoenoic alcohol species were detected.
New developments in hydrogen gas generation molecular sieves
Authors: Priddy Max H.
Published: June 2007

The use of molecular sieves as a means of purifying steam‐reformed hydrocarbon fuel in the production of low cost hydrogen has been developed into a practical gas generator design. Conventional processes for producing hydrogen are reviewed, with a history of molecular sieves and how this dry desiccant material was applied to commercial equipment as an adsorbent for removal of CO2 and water vapor. The molecular sieve type hydrogen gas generator is discussed with an outline of typical operating cost and gas purity capabilities.
The PAT‐20, varian’s new NMR process analyzer
Authors: Andersson L. O.
Published: June 2007

Varian’s earlier process analyzer, the PA‐7, is now being replaced by a new solid state instrument, the PAT‐20, with improved reliability and performance and simplified operation. The instrument measures the NMR signal of the protons in the sample, integrating the narrow line to give a quick and accurate quantitative analysis of water or oil in a previously weighed sample. The result can be displayed on a recorder or on a digital readout. It can also be fed directly into a computer for on line process regulation. A short description of the construction of the instrument is given and the principles of operation are explained.
Transient NMR quantitative measurements
Authors: Persyn G. A. , Rollwitz W. L.
Published: June 2007

The transient nuclear magnetic resonance technique is briefly described. Application of this technique allowed quantitative observation of the protons in the oil, water and solid material in a single corn kernel and on a corn kernel baked at 107 C. These results along with measurements on lyophilized foods are discussed.
Inactivation of aflatoxins in peanut and cottonseed meals by ammoniation
Authors: Gardner H. K. , Koltun S. P. , Dollear F. G. , Rayner E. T.
Published: June 2007

Aflatoxins in peanut and cottonseed meal can be inactivated by treatment with gaseous ammonia. In pilot plant runs, contaminated peanut meal was ammoniated at two levels each of moisture content, reaction time, temperature and ammonia pressure. Thin layer chromatography indicated that ammoniation inactivated the aflatoxins (121 ppb) in the meal to a nondetectable level. With a similar treatment, total aflatoxins (350 ppb) in cottonseed meal were reduced to 4 ppb. A series of runs was made with large scale equipment using cottonseed meal containing an average of 519 ppb total aflatoxins. Under optimum processing conditions, aflatoxin content of this meal was reduced to below 5 ppb and non‐detectable levels.
Norsolorinic acid from a mutant strain ofAspergillus parasiticus
Authors: Lee Louise S. , Bennett Joan W. , Goldblatt L. A. , Lundin R. E.
Published: June 2007

A mutant formed after UV irradiation of a potent aflatoxin producing strain ofAspergillus parasiticus elaborated 80% less aflatoxin than did the parent strain and produced an orange‐red pigment. This new metabolite which represents 1% of the mycelial mass has been identified as 2‐hexanoyl‐1,3,6,8‐tetrahydroxyanthraquinone (norsolorinic acid), mol wt 370, mp 256–257 C, and molecular formula C20H18O7.
Breeding rapeseed for oil and meal quality
Authors: Downey R. K. , Craig B. M. , Youngs C. G.
Published: June 2007

Significant variation in fatty acid composition occurs within the seed oils of theBrassica genus, which includes the mustards and rapeseed. Research into the inheritance and biosynthesis of fatty acids has shown that at least two biosynthetic pathways exist in the developing rapeseed and some of the steps are under direct genetic control. The plant breeder has the basic knowledge in this oilseed crop to produce seed oils with defined fatty acid composition, and a practical example is the commercial development of Canbra oil, the rapeseed oil from which erucic acid has been eliminated.Brassica seed meals contain thioglucosides which may cause metabolic disturbances when fed to certain classes of livestock. The major thioglucosides in rapeseed meal are those giving rise to 3‐butenyl and 4‐pentenyl isothiocyanate and 5‐vinyl‐2‐oxazolidinethione. Partial success in eliminating these compounds has been achieved by breeding strains of turnip rape (B. campestris) which do not contain the glucosides of 4‐pentenyl isothiocyanate and oxazolidinethione, and the identification of aB. napus variety with very low levels of all three glucosides. These findings suggest that complete removal of these sulfur compounds may be possible through plant breeding.