Mechanism of high-temperature sulphide corrosion of metals and alloys

Sulfidation appears to be considerably more suitable than oxidation for studying the high-temperature behaviour of metals. Sulfide scales are formed at considerably higher rates and at lower temperatures, in addition it is much easier to work with the radioactive sulfide isotope. The experiments can be conducted in sulfur vapour or in hydrogen/hydrogen sulfide mixtures; differences are due only to different sulfur partial pressures. Sulfide scale is formed on pure metals (e. g. Cu, Ag, Ni) as well as in binary or ternary alloys. (e. g. FeNi, NiCr, CuZn, CoCr, FeCrAl) with consistantly reproducible results. Irrespective of scale thickness and structure the reaction rates are always controlled by outward diffusion with the high defect concentration favouring high reaction rates. Since various metals tend to form low melting metal/metal sulfide eutectics, it is necessary to keep temperatures below the particular melting point. Contrary to inner oxidation there is no inner sulfidation. The protective action of sulfide scale is considerably inferior to that of oxide scale. According to the results of the present compilation no material has become available which combines sufficient scaling resistance with good high-temperature mechanical properties. Solution of this problem may perhaps be found by adding rare earth metals.     

Interesterification products and processes

Interesterification as applied to fats and oils is a process whereby the fatty, acid moieties of glyceride molecules are rearranged in a random or directed manner. Either type of rearrangement may involve production of new triglyceride compositions in a predictable manner. A number of patented processes for accomplishing interesterification are discussed. Effective rearrangement catalysts are listed. Typical applications to commercial products are reviewed. Presented at the AOCS Short Course, East Lansing, Aug. 29–Sept. 1, 1966.     

Evaluation and comparison of two efficient probabilistic primality testing algorithms

We analyse two recent probabilistic primality testing algorithms; the first one is derived from Miller [6] in a formulation given by Rabin [7], and the second one is from Solovay and Strassen [9]. Both decide whether or not an odd number n is prime in time O(m, lognM(n)) with an error probability less than α^m, for some $\text{0≤a<}\text{1}\text{2}$. Our comparison shows that the first algorithm is always more efficient than the second, both in probabilistic and algorithmic terms.     

Are hypertensives less assertive? A controlled evaluation.

Assessed the performance of 12 male hypertensives (mean age 47.36 yrs) in increasingly demanding interpersonal interactions. 12 extended role-played scenes incorporating the expression of positive and negative emotional states were used. Behavioral, physiological, and subjective ratings were obtained. Performance of the hypertensives was compared to that of both patient and nonpatient normotensive Ss who were carefully matched with the hypertensives on a number of demographic variables. Results indicate that the hypertensives responded less assertively on a number of dimensions than did the nonpatient comparison group. However, the performance of the normotensive patient group was similar to that of the hypertensive patients. Physiological and subjective data indicated comparable responding across all 3 experimental groups. The discussion focuses on the existence of a chronic-illness syndrome that potentially has strong behavioral correlates. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

New developments in the inelastic analysis of quasistatic and dynamic problems

The computational aspects are examined for the numerical analysis of inelastic structures and continua. In this context, the tracing of quasistatic and dynamic motions is considered with particular emphasis on the interaction of nonlinear and transient problems. In the first part, explicit and implicit solution schemes are developed for the numerical integration of inelastic first-order rte processes governing creep, viscoelasticity and viscoplasticity. In the second part, the exposition is extended to second-order inertial problems and in particular to the field of dynamic plasticity, devoting special attention to the kinematics of finite deformation problems.     

Network design taking into account breakdowns and traffic overloads

Models and algorithms are presented enabling an evaluation of the traffic efficiency of a telephone network under abnormal working conditions and an optimization of network structures with reliability requirements.