Isolated prompt photon photoproduction at NLO

We present a full next-to-leading order code to calculate the photoproduction of prompt photons. The code is a general purpose program of “partonic event generator” type with large flexibility. We study the possibility to constrain the photon structure functions and comment on isolation issues. A comparison to the ZEUS data is also shown. Received: 16 May 2001 / Revised version: 14 June 2001 / Published online: 19 July 2001     

A197Au and57Fe mössbauer study of the roasting of refractory gold ores

The transformation of chemically bound gold into metallic gold during industrial scale roasting of an arsenical gold ore concentrate from the Fairview Mine, Eastern Transvaal, has been studied quantitatively by¹⁹⁷Au Mössbauer spectroscopy. The iron compounds in the concentrate, mainly FeAsS and FeS₂ and their transformations during roasting have been studied by⁵⁷Fe Mössbauer spectroscopy. The bound gold is found to convert into the metal in parallel to the decomposition of FeAsS and the increase in cyanide leachability. this shows that the refractory character of the ore is caused by the chemical bonding of the gold rather than by the physical inclusion of small, discrete metallic particles in the matrix of FeAsS or FeS₂. The ratio of thef-factors of gold bound in the FeAsS component of a refractory ore and of metallic gold was determined to bef(Au:FeAsS)/f(Au)=1.48±0.09.     

Polycaprolactone-based block copolymers. II. Morphology and crystallization of copolymers of styrene or butadiene and ε-caprolactone

Three series of amorphous semicrystalline poly(styrene-b-ε-caprolactone)s have been synthesized with polystyrene blocks of 6000 (series A), 40000 (series B), and 70000 (series C) molecular weight, respectively. In these materials, the polymer miscibility evolves from a situation where a diffuse interphase involves the major part of the volume of the copolymer (series A) to a sharp phase separation as observed for copolymers with the longest PS block (series C). The crystallization of PCL blocks is mainly governed by the phase morphology. In copolymers of series A, the crystallization rate of PCL blocks is slowed down the more as the miscibility with PS increases, and ultimately the degree of crystallinity X_c decreases significantly. When phase separation is sharp, X_c changes dramatically at the phase inversion and decreases when PS forms the continuous phase. At the inversion X_c depends on the mean size of the PCL microdomains as compared with the thickness of the crystalline lamellae. The periodicity of the phase morphology as observed by TEM is influenced by the solvent used in casting films, whereas monolamellar monocrystals can be obtained by a self-seeding technique.     

Application of mathematical programming in planning of human diets

Mathematical programming models have been developed to find utility maximized nutritious diets. The utility maximized diets have been shown to be more practical, more realistic, and less costly than the non-utility maximized diets. In this study we further increase the desirability of diets by gradually softening those nutrients which have been supplied by the foods in the diet at a cost which is above the market price of the respective nutrient. Marginal analysis is used to find marginal costs of the nutrients. The parametric quadratic programming is used to find the optimum diet where the cost of nutrient is equal to the market price of the nutrient supplement. The resulting diet is more desireable and less costly than the previous diets.     

Numerical Simulation of a Nonlinear Parabolic Equation for Analyzing The Perceived Loudness Statistics of Sonic Boom Wave after Propagation Through Atmospheric Turbulent Layer

Acoustical Physics - Soniс boom propagation in the atmospheric turbulent layer, represented by a model of homogeneous isotropic turbulence, is investigated numerically in two-dimensional...     

Recent advances in notch analysis of fracture and fatigue

Summary Neuber's micro- and macrosupport effect theories are applied to obtain on expression for the plastic work required for crack extension. On this basis analytical predictions for fracture toughness, thickness effects and fatigue crack propagation threshold are made and found in very good agreement with experimental results.

---

Übersicht Mit Hilfe der Neuberschen Theorie der Mikro- und Makrostützwirkung wird eine allgemeine Formulierung für die Rißerweiterungskraft bei nichtlinearem Werkstoffverhalten hergeleitet. Darauf aufbauend werden die Rißzähigkeit, Dickeneffekte und Rißstop bei Schwingbeanspruchung theoretisch behandelt und eine sehr gute Übereinstimmung mit Versuchsergebnissen festgestellt.

---

---

Dedicated to o. Prof. Dr.-Ing. Dr. rer. nat. h. c. H. Neuber.