IBM Journal of Research and Development

High fuel costs and potential shortages of petroleum-based energy resources have placed increasing emphasis on the need both to conserve our present resources and to develop alternate energy sources. Proposed alternatives that represent renewable energy sources are particularly intriguing; some of these are nuclear energy, solar energy, geophysical forces, and biomass. This issue contains a groupi... View full abstract»

Economically viable means of producing silicon solar cells for the conversion of solar energy into electric power are discussed. Emphasis is given to the discussion of crystal growth techniques capable of growing single-crystal silicon ribbons directly and inexpensively from molten silicon. The capillary action shaping technique (CAST) recently developed by IBM has a good potential for producing l... View full abstract»

Films of polycrystalline GaAs have been grown on foreign substrates by the metal-organic process. The main objective was to produce films with as large a grain size as possible, so that high-efficiency photovoltaic devices may eventually be fabricated from such thin film/substrate structures. At 973 K the average grain size was less than 1 µm, and was unaffected by the choice of substrate. ... View full abstract»

The photovoltaic properties of Schottky barrier sandwich cells consisting of sublimed and solution-cast thin films of selected squarylium (bis-anilino derivatives of cyclobuta-1,3-diene-2,4-dione) and cyanine-tetracyanoquinodimethanide (TCNQ) dyes have been measured. For hydroxy squarylium (OHSq), maximum power conversion efficiencies (η) were 0.2% for 850-nm light (1 mW/cm2); 0.... View full abstract»

Anodization of textured tungsten is shown to have merit either in creating a solar absorber of extremely high absorptance when applied to a large dendritic surface, or in enhancing the solar absorptance-to-emittance ratio when applied to smaller hillock topographies. The angular dependence of the absorption is reduced by the anodization coating, which consists of a thin conformal coating of WO View full abstract»

There are several public domain, and numerous proprietary, computer programs that provide detailed simulations of the heating and cooling requirements for a building. Such programs are often used to evaluate changes in the design of a building that are made to decrease its energy requirements. A user is considered to be working in a trial-and-error mode if each execution of the program provides no... View full abstract»

When principal axis transformations are applied to multispectral scanner (MSS) data, the majority of data variability is shown to be contained in the first two or three components. This paper describes a method for generating a color composite picture from these components whereby most of the information collected by an MSS can be conveyed in a single color picture. The first component is found to... View full abstract»

A technique for the validation of protocols in communications systems is described. It can be used for systems composed of processes that can be modeled as finite directed graphs. The validation exhaustively exercises the interaction domain of a system and identifies all occurrences of a number of well-defined error conditions. The method can detect when individual processes have no predefined res... View full abstract»

Consider a paged storage hierarchy with at least two levels L1 and L2, where L1 denotes main storage and L2 secondary storage. Suppose that the unit of replacement for L1 is a single page, and that the L2-to-L1 transfer unit, given a page fault, is an integer number of pages. Then, given a suitable replacement policy for ... View full abstract»

The problem of writing machine-independent APL interpreters is solved by means of a systems programming approach making use of an intermediate level language specially designed for that purpose. This paper describes the language, as well as the procedure used to build universal interpreters. Three compliers that translate this language for three different machines have been written so far, and an ... View full abstract»

Empirical regression equations permit the calculation of liquid phase epitaxial (LPE) film properties from film growth parameters. Numerical differentiation of these equations facilitates examination of the sensitivities of film properties to fluctuations in growth conditions and the development of depletion-compensating growth strategies. Regression equations for nominal 3-µm bubble size C... View full abstract»

This communication suggests the feasibility of a single-component scheme for representing complex numbers with real bases. Several advantages are pointed out, including the very simple extraction of the real and imaginary parts of a complex number. View full abstract»

Reprints of the papers listed here may usually be obtained by writing directly to the authors. The authors' IBM divisions are identified as follows: DPD is the Data Processing Division; FED, Field Engineering Division; FSD, Federal Systems Division; GPD, General Products Division; GSD, General Systems Division; GTD, General Technology Division; OPD, Office Products Division; RES, Research Division... View full abstract»