Role of Mg on Structure and Mechanical Properties in Alloy 718

The role of Mg in alloy/718 has been systematically investigated. Mg raises not only high temperature tensile and stress-rupture ductilities but also increases considerably smooth and notch stress-rupture life. Mg containing alloy 718M is free of stress-rupture notch sensitivity. Mg improves creep and fatigue interaction properties (LCF or cyclic stress rupture) at any grain size. The basic role of Mg is equilibrium segregation at grain boundaries which helps to change continuous grain beundary (5-Ni3Nb morphology to discrete globular form which has a retardation effect on intergranular fracture. Mg promotes the change from intergranular to transgranular fracture mode.     

The design of an epistemology for the management discipline which resolves dilemmas among ethical and other imperatives

We outline an epistemology to resolve dilemmas among conflicting imperatives which arise in management situations involving action programs which are “useful” economically and technically but which, at the same time, must satisfy, among others, aesthetic, ethical, and legal requirements. These “situations” occur in problem domains such as management science, environmental management, conservation management (the science devoted to the protection and preservation of our cultural and historical heritage), urban planning, government administration, and the like. Basically, these actions programs are designed to “improve the state of the real world” and take into account the inevitable conflicts and tradeoffs which inhibit maximization of objectives. In the end, the epistemological framework which is proposed leads to the formulation of a methodology to reconcile the economic, scientific, political, legal, ethical, epistemological, and aesthetic imperatives, in the context of a strategic and pragmatic framework.     

Structure of a genomic clone encoding biologically active human relaxin

Relaxin is a peptide hormone synthesized in the corpora lutea of ovaries during pregnancy and is released into the blood stream prior to parturition. Its major biological effect is to remodel the mammalian reproductive tract to facilitate the birth process. Determination of the structure of human relaxin is thus a first step in opening up the possibility of clinical intervention in cases of difficult labour. However, the limited availability of human ovaries during pregnancy has prevented both direct amino acid sequence determination and isolation of cDNA clones obtained from relaxin producing tissue. Our approach has therefore been to screen directly for a human relaxin gene using an homologous porcine relaxin cDNA probe. We report here the successful identification of a genomic clone from which the structure of the entire coding region of a human preprorelaxin gene has been determined. Synthesis of biologically active relaxin has shown that the novel gene structure described herein codes for an authentic human relaxin. We believe this is the first successful synthesis of a biologically active hormone whose structure was predicted solely from the structure of a genomic clone.     

STRATEGIC EXERCISE OF REAL OPTIONS：INVESTMENT DECISIONS IN TECHNOLOGICAL SYSTEMS

Viewing investment projects in new technologies as real options, this paper studies the effects ofendogenous competition and asymmetric information on the strategic exercise of real options. We firstdevelop a multi-period, game-theoretic model and show how competition leads to early exercise andaggressive investment behaviors and how competition erodes option values. We then relax the typicalfull-information assumption found in the literature and allow information asymmetry to exist acrossfirms. Our model shows, in contrast to the literature that payoff is independent of the ordering ofexercise, that the sequential exercise of real options may generate both informational and payoffexternalities. We also find some surpising but interesting results such as having more information isnot necessarily better.     

Modelling peak electricity demand

This paper estimates a forecasting equation for the hourly peak electricity demand one day in the future. The models incorporate deterministic influences such as holidays, stochastic influences such as average loads by building bivariate models, and exogenous influences such as the weather which is given a careful non-linear formulation. Out-of-sample comparisons are made using an additional year of data.     

Einstein,Nordström and the early demise of scalar,Lorentz-covariant theories of gravitation

Conclusion The advent of the general theory of relativity was so entirely the work of just one person — Albert Einstein — that we cannot but wonder how long it would have taken without him for the connection between gravitation and spacetime curvature to be discovered. What would have happened if there were no Einstein? Few doubt that a theory much like special relativity would have emerged one way or another from the researchers of Lorentz, Poincaré and others. But where would the problem of relativizing gravitation have led? The saga told here shows how even the most conservative approach to relativizing gravitation theory still did lead out of Minkowski spacetime to connect gravitation to a curved spacetime. Unfortunately we still cannot know if this conclusion would have been drawn rapidly without Einstein's contribution. For what led Nordström to the gravitational field dependence of lengths and times was a very Einsteinian insistence on just the right version of the equality of inertial and gravitational mass. Unceasingly in Nordström's ear was the persistent and uncompromising voice of Einstein himself demanding that Nordström see the most distant consequences of his own theory.