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IBM Journal of Research and Development

Issue 4 • Date July 1978

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Displaying Results 1 - 16 of 16
  • Preface

    Publication Year: 1978 , Page(s): 334
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (119 KB)  

    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 grouping of five papers that represent a few of the many contributions by workers within IBM in the various areas of energy research. View full abstract»

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  • Low Cost Silicon for Solar Energy Conversion Applications

    Publication Year: 1978 , Page(s): 335 - 345
    Cited by:  Papers (2)  |  Patents (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (769 KB)  

    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 low cost silicon sheets suitable for solar cells. This technique has produced ribbon 100 mm wide and 0.3 mm thick. Problems that CAST must overcome in order to supply material for low cost solar cells are discussed. Economic and technological computer-modeled comparisons indicate that continuously grown CAST ribbons of these dimensions can meet a cost objective below $50/m2 of sheet material. The results require that it be possible to fabricate a twelve-percent-efficient solar cell from CAST ribbon 100 mm wide and 0.3 mm thick at a polycrystalline silicon cost of $10/kg. View full abstract»

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  • Growth of Polycrystalline GaAs for Solar Cell Applications

    Publication Year: 1978 , Page(s): 346 - 352
    Cited by:  Papers (1)  |  Patents (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (581 KB)  

    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. Increasing the deposition temperature to 1123 K, while maintaining all other conditions the same, resulted in grains as large as 10 to 20 µm in diameter. Grain sizes as large as 10 µm could be obtained by precoating the substrates with thin films of evaporated gold or tin. However, both of these methods gave films that were discontinuous. A two-step procedure in which the films were nucleated at 873 K prior to growth at 1123 K yielded continuous films with an average grain size of 5 µm. Schottky barrier solar cells fabricated from these films exhibited short-circuit current densities as high as 15.7 mA/cm2, even though the highest conversion efficiency (AM0, uncoated) was only 1.3 percent because of the low fill factor (0.28). View full abstract»

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  • Organic Photovoltaic Materials: Squarylium and Cyanine-TCNQ Dyes

    Publication Year: 1978 , Page(s): 353 - 371
    Cited by:  Patents (4)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (986 KB)  

    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); 0.05% for 633-nm light (94 mW/cm2); 0.06% for “white” light (21 mW/cm2); 0.15% for low intensity (0.14 mW/cm2) simulated AM0 light (sunlight under outer space conditions), and 0.02% for high intensity (140 mW/cm2) AM0 light. Efficiencies of selected OHSq cells were observed to increase fivefold when the cells were doped with bromine or 1-phenyl-3-p-N, N-diethylaminostyryl-5-p-N,N-diethylaminophenyl-Δ2-pyrazoline (DEASP), e.g., 0.05 to 0.23% (Br); 0.004 to 0.021% (DEASP). The efficiency of a solution-cast cell of amorphous 2,2′-dicarbocyanine-TCNQ was 0.02% when 933-nm light (approximately (1 mW/cm2) was used. Amorphous solid solutions of 1,1′-diethyl-2,2′-dicarbocyanine-and oxa-2,2′-dicarbocyanine-TCNQ salts were also tested. The effects of various material and device properties on the performance of organic photovoltaic cells are discussed, and it is proposed that organic solar cells having efficiencies of one percent or more can be made by using existing technologies. View full abstract»

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  • Solar Absorbing Surfaces of Anodized Dendritic Tungsten

    Publication Year: 1978 , Page(s): 372 - 377
    Cited by:  Patents (4)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (377 KB)  

    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 WO3. The surface is stable up to temperatures of 520 K in air. View full abstract»

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  • Optimization Applied to the Design of an Energy-Efficient Building

    Publication Year: 1978 , Page(s): 378 - 385
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (486 KB)  

    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 formal guidance for the next change. This work reports on an investigation of the imbedding of such an energy analysis program into an optimization structure. Such an arrangement would enable a user to specify a set of architectural and construction parameters and the limits within which they might vary, and from this to determine the parameters that yield a local minimum in thermal load and the sensitivity of this load to changes in these parameters. View full abstract»

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  • Color Composite Pictures from Principal Axis Components of Multispectral Scanner Data

    Publication Year: 1978 , Page(s): 386 - 392
    Cited by:  Papers (5)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (517 KB)  

    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 be a weighted sum of image data from all channels, and therefore it is natural to associate the first component with brightness. To be consistent with this interpretation, only the first component of the transformed data is used to control the brightness of the color composite picture. View full abstract»

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  • General Technique for Communications Protocol Validation

    Publication Year: 1978 , Page(s): 393 - 404
    Cited by:  Papers (45)  |  Patents (3)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (591 KB)  

    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 response to incoming messages, as well as system deadlocks and potential loss of messages due to overflow conditions. View full abstract»

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  • Adaptive Variation of the Transfer Unit in a Storage Hierarchy

    Publication Year: 1978 , Page(s): 405 - 412
    Cited by:  Patents (7)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (465 KB)  

    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 L1, increasing the unit of transfer often results in a lower miss ratio at the expense of increased paging traffic. This paper explores the possibility of adaptively varying the L2-to-L1 transfer unit as a function of the reference history of the data to be fetched. Experiments on traces drawn from two large data base systems suggest that such adaptation can result in improved tradeoffs between miss ratios and paging traffic. View full abstract»

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  • A Machine-Independent APL Interpreter

    Publication Year: 1978 , Page(s): 413 - 421
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (499 KB)  

    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 APL interpreter has been finished. View full abstract»

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  • Regression Model for LPE Film Property Control

    Publication Year: 1978 , Page(s): 422 - 428
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (448 KB)  

    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 CaGe and Ga films have been generated and used for quantitative comparisons of the growth behavior of the two systems. A real time feedback control scheme has been applied to the Ga system resulting in 70 percent of the as-grown films falling within ±1 percent of the target collapse field. View full abstract»

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  • Representation for Complex Numbers

    Publication Year: 1978 , Page(s): 429 - 430
    Cited by:  Papers (3)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (241 KB)  

    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»

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  • Recent Papers by IBM Authors

    Publication Year: 1978 , Page(s): 431 - 435
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (414 KB)  

    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; SCD, System Communications Division; and SPD, System Products Division. Journals are listed alphabetically by title; papers are listed sequentially for each journal. View full abstract»

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  • Recent IBM Patents

    Publication Year: 1978 , Page(s): 436 - 437
    Save to Project icon | PDF file iconPDF (223 KB)  
    Freely Available from IEEE
  • Authors

    Publication Year: 1978 , Page(s): 438 - 440
    Save to Project icon | PDF file iconPDF (1196 KB)  
    Freely Available from IEEE
  • Contents of previous issues

    Publication Year: 1978 , Page(s): 441 - 442
    Save to Project icon | PDF file iconPDF (236 KB)  
    Freely Available from IEEE

Aims & Scope

The IBM Journal of Research and Development is a peer-reviewed technical journal, published bimonthly, which features the work of authors in the science, technology and engineering of information systems.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Clifford A. Pickover
IBM T. J. Watson Research Center