Further Study on the Comparison of the Ream Motility Test with the Rotary Activity Test

The primary purpose of this study was to determine the degree of relationship, if any, between two different methods of measuring motility. Seashore (4) and others have used motility as a means of measuring skill such in musical performance. Ream\u27s technique (3) for measuring motility has been criticized on the grounds that it is possible for a subject to tense his muscles and thus obtain a spuriously high score from involuntary tremor under certain conditions. Similarly some subjects tend to tense themselves and thus to introduce hindrances in function which seems to lower their score. It is thought that these discrepancies indicate a fault in the measurement of motility when using the Ream method

DEVELOPMENT ECONOMICS: PAST AND FUTURE

This article appraises the progress in the evolution of ideas that has been accomplished by the first two generations of development economists and focuses on the unsettled questions and unfinished tasks for the next generation. The intention is not to present yet another survey of the literature, but rather to offer a subjective summary appraisal of the past and future of the subject

A CRITIQUE OF THE NEW BRITISH MONOPOLY ACT

In 1948 the British Parliament passed the Monopoly and Restrictive Practices (Inquiry and Control) Act. It is instructive to examine this Act against the background of the criticisms and suggestions for improvement which have emerged with sixty years of American anti-trust legislation. Section one of this paper presents some reasons why the measure has appeared at this time. The next section summarizes the Act\u27s provisions. Section three contrasts the British technique of monopoly control with the American and considers whether the different approach is likely to avoid the debilities which have become evident in the American legislation

Comparative Costs Revisited

The theory of comparative advantage is the oldest – and most fundamental – principle in international economics. Its empirical significance, however, changes with the times. Given the intensification of the forces of globalisation, the importance of comparative costs should now be revisited in order to consider dynamic changes in the global economy, the connection between a country’s comparative advantage and a firm’s competitive advantage, and the effects on more developed countries of trade with less developed countrie

Non-aqueous cleaning solvent substitution

A variety of environmental, safety, and health concerns exist over use of chlorinated and fluorinated cleaning solvents. Sandia National Laboratories, Lawrence Livermore National Laboratories, and the Kansas City Division of AlliedSignal have combined efforts to focus on finding alternative cleaning solvents and processes which are effective, environmentally safe, and compliant with local, state, and federal regulations. An alternative solvent has been identified, qualified, and implemented into production of complex electronic assemblies, where aqueous and semi-aqueous cleaning processes are not allowed. Extensive compatibility studies were performed with components, piece-parts, and materials. Electrical testing and accelerated aging were used to screen for detrimental, long-term effects. A terpene, d-limonene, was selected as the solvent of choice, and it was found to be compatible with the components and materials tested. A brief history of the overall project will be presented, along with representative cleaning efficiency results, compatibility results, and residual solvent data. The electronics industry is constantly searching for proven methods and environmentally-safe materials to use in manufacturing processes. The information in this presentation will provide another option to consider on future projects for applications requiring high levels of quality, reliability, and cleanliness from non-aqueous cleaning processes

Fundamental Studies of the Durability of Materials for Interconnects in Solid Oxide Fuel Cells

Ferritic stainless steels are a leading candidate material for use as an SOFC interconnect, but have the problem of forming volatile chromia species that lead to cathode poisoning. This project has focused both on optimization of ferritic alloys for SOFC applications and evaluating the possibility of using alternative materials. The initial efforts involved studying the oxidation behavior of a variety of chromia-forming ferritic stainless steels in the temperature range 700-900 C in atmospheres relevant to solid oxide fuel cell operation. The alloys exhibited a wide variety of oxidation behavior based on composition. A method for reducing the vaporization is to add alloying elements that lead to the formation of a thermally grown oxide layer over the protective chromia. Several commercial steels form manganese chromate on the surface. This same approach, combined with observations of TiO{sub 2} overlayer formation on the chromia forming, Ni-based superalloy IN 738, has resulted in the development of a series of Fe-22 Cr-X Ti alloys (X=0-4 wt%). Oxidation testing has indicated that this approach results in significant reduction in chromia evaporation. Unfortunately, the Ti also results in accelerated chromia scale growth. Fundamental thermo-mechanical aspects of the durability of solid oxide fuel cell (SOFC) interconnect alloys have also been investigated. A key failure mechanism for interconnects is the spallation of the chromia scale that forms on the alloy, as it is exposed to fuel cell environments. Indentation testing methods to measure the critical energy release rate (Gc) associated with the spallation of chromia scale/alloy systems have been evaluated. This approach has been used to evaluate the thermomechanical stability of chromia films as a function of oxidation exposure. The oxidation of pure nickel in SOFC environments was evaluated using thermogravimetric analysis (TGA) to determine the NiO scaling kinetics and a four-point probe was used to measure the area-specific resistance (ASR) to estimate the electrical degradation of the interconnect. In addition to the baseline study of pure nickel, steps were taken to decrease the ASR through alloying and surface modifications. Finally, high conductivity composite systems, consisting of nickel and silver, were studied. These systems utilize high conductivity silver pathways through nickel while maintaining the mechanical stability that a nickel matrix provides