A Simple Sequential Reasoning Approach for Sound Modular Verification of Mainstream Multithreaded Programs

Reasoning about multithreaded object-oriented programs is difficult, due to the non-local nature of object aliasing, data races, and deadlocks. We propose a programming model that prevents data races and deadlocks, and supports local reasoning in the presence of object aliasing and concurrency. Our programming model builds on the multi-threading and synchronization primitives as they are present in current mainstream languages. Java or C# programs developed according to our model can be annotated by means of stylized comments to make the use of the model explicit. We show that such annotated programs can be formally verified to comply with the programming model. In other words, if the annotated program verifies, the underlying Java or C# program is guaranteed to be free from data races and deadlocks, and it is sound to reason locally about program behavior. Our approach supports immutable objects as well as static fields and static initializers. We have implemented a verifier for programs developed according to our model in a custom build of the Spec# programming system, and have validated our approach on a case study.     

Inequational Deduction as Term Graph Rewriting

Multi-algebras allow to model nondeterminism in an algebraic framework by interpreting operators as functions from individual arguments to sets of possible results.We propose a simple inequational deduction system, based on term graphs, for inferring inclusions of derived relations in a multi-algebra, and we show that term graph rewriting provides a sound and complete implementation of it.     

Study of FePt films prepared by reactive sputtering

In the present study, ⁵⁷FePt films are prepared with reactive ion beam sputtering using mixture of argon and nitrogen gases. Energy-dispersive X-ray reflectivity is used to estimate the thickness of the as-deposited films. Structural and magnetic properties of the as-deposited and annealed films are studied using grazing incidence X-ray diffraction (GIXRD), magneto-optical Kerr effect (MOKE) and conversion electron Mossbauer spectroscopy (CEMS). Significant difference in structural and magnetic properties i.e., formation of ordered L1₀ phase and perpendicular magnetic anisotropy are observed for the films prepared with mixture of nitrogen and argon as compared to the film prepared with argon only. From the GIXRD, peaks corresponding to the ordered face-centred tetragonal FePt phase are observed for the films prepared with mixture gas. The results of CEMS clearly show the perpendicular magnetic anisotropy (PMA) for the films prepared with mixture of nitrogen and argon. The observed enhanced chemical ordering and the development of PMA in the films prepared with mixture gas is due to the role played by the defects created as a consequence of nitrogen escape in the films with high temperature annealing.     

Kinetic investigation of Eu(III)-humate interactions by ion exchange resins

The kinetic stability of radionuclides bound to aqueous colloids is a determining factor in their migration from a radioactive waste repository. The cation exchangers Chelex-100, Dowex 50Wx4, and Cellphos (cellulose phosphate) have been shown a promising tool for kinetic investigations. This study assesses the applicability of different exchange resins for Eu humate dissociation kinetics investigations. All resins were found to produce satisfactory results. A systematic study of parameters affecting the dissociation rates of Eu(III) humate complexes was performed. A set of purified humic substances was found to behave in the same way. However, unpurified Aldrich humic acid showed significant differences.     

Wachstumsformen von Aluminiumoxiden in Stählen

Aluminiumoxidformen in Schmelzen mit und ohne Konvektion. Lichtmikroskopische und rasterelektronenmikroskopische Untersuchungen. Einfluß der Sauerstoffaktivität auf das Al₂O₃–Wachstum. Einfluß der Erstarrungsbedingungen auf das Al₂O₃–Wachstum. Stoffstromdichten und Konzentrationen. Konzentrationsverteilungen und Schlieren. Übersättigungen.     

Structural regularity and crystallization of lithium polyisoprene and poly(styrene-b-isoprene-b-styrene)

Summary By anionic polymerization in cyclohexane with secbutyllithium as initiator polyisoprene and poly (styrene-b-isoprene-b-styrene) have been prepared with 92 mole % and 90 mole % cis-1, 4 isoprene structural units respectively. From the¹³C NMR spectrum there is no evidence for chain reversals of the polyisoprene chain, which was claimed to prevent crystallization in lithium polyisoprenes in the unstretched state. By DSC it is shown that the polyisoprene sample crystallizes in the isotropic state at –25°C. The block copolymer shows stress induced crystallization as demonstrated by temperature dependent stressstrain measurements.Dedicated to Prof. Dr. G. Rehage on the occasion of his 60th birthday