4,996 research outputs found

    The Perfect Binary One-Error-Correcting Codes of Length 15: Part II--Properties

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    A complete classification of the perfect binary one-error-correcting codes of length 15 as well as their extensions of length 16 was recently carried out in [P. R. J. \"Osterg{\aa}rd and O. Pottonen, "The perfect binary one-error-correcting codes of length 15: Part I--Classification," IEEE Trans. Inform. Theory vol. 55, pp. 4657--4660, 2009]. In the current accompanying work, the classified codes are studied in great detail, and their main properties are tabulated. The results include the fact that 33 of the 80 Steiner triple systems of order 15 occur in such codes. Further understanding is gained on full-rank codes via switching, as it turns out that all but two full-rank codes can be obtained through a series of such transformations from the Hamming code. Other topics studied include (non)systematic codes, embedded one-error-correcting codes, and defining sets of codes. A classification of certain mixed perfect codes is also obtained.Comment: v2: fixed two errors (extension of nonsystematic codes, table of coordinates fixed by symmetries of codes), added and extended many other result

    Fabrication and performance analysis of 4-sq cm indium tin oxide/InP photovoltaic solar cells

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    Large-area photovoltaic solar cells based on direct current magnetron sputter deposition of indium tin oxide (ITO) into single-crystal p-InP substrates demonstrated both the radiation hardness and high performance necessary for extraterrestrial applications. A small-scale production project was initiated in which approximately 50 ITO/InP cells are being produced. The procedures used in this small-scale production of 4-sq cm ITO/InP cells are presented and discussed. The discussion includes analyses of performance range of all available production cells, and device performance data of the best cells thus far produced. Additionally, processing experience gained from the production of these cells is discussed, indicating other issues that may be encountered when large-scale productions are begun

    Effect of high-dose melphalan on marrow and intestinal epithelium in mice pretreated with cyclophosphamide.

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    The lethal effect of high-dose melphalan in mice could be offset by pretreatment with cyclophosphamide, cytosine arabinoside or low-dose melphalan. The reason for improved survival is unclear. Althoug animals given high-dose melphalan died with symptoms of gut death, in only one instance, that with low-dose melphalan itself, did pretreatment protect the intestinal epithelium as measured by the microcolony assay. A small enhancement in the recovery of the haemopoietic tissue in pretreated animals was noted, although this on its own is unlikely to explain the phenomenon. Experiments in tumour-bearing mice showed that pretreatment with cyclophosphamide did not reduce the toxicity of melphalan to the Lewis lung carcinoma

    Steak Location Within the Semitendinosus Muscle Impacts Metmyoglobin Accumulation on Steaks During Retail Display

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    Beef color is a major attribute consumers utilize to make purchasing decisions. It is estimated poor color shelf-life of beef steaks costs the meat industry more than $1 billion annually. Shelf-life color is influenced by a balance of two biochemical processes within steaks: metmyoglobin reducing ability and oxygen consumption. Steaks that exhibit a greater metmyoglobin reducing and a reduced oxygen consumption are typically characterized as more color stable. Characteristics of the muscle fiber or muscle cell are what determine the properties of a steak. Commonly, muscles with more oxidative fibers have an elevated oxygen consumption and reduced metmyoglobin reducing ability. The Semitendinosus muscle or eye of round possesses a divergent muscle fiber isoform distribution based on the location steaks are fabricated. The objective of this study was to examine effects of steak location on muscle fiber type distribution and metmyoglobin accumulation of Semitendinosus steaks

    Two Optimal One-Error-Correcting Codes of Length 13 That Are Not Doubly Shortened Perfect Codes

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    The doubly shortened perfect codes of length 13 are classified utilizing the classification of perfect codes in [P.R.J. \"Osterg{\aa}rd and O. Pottonen, The perfect binary one-error-correcting codes of length 15: Part I - Classification, IEEE Trans. Inform. Theory, to appear]; there are 117821 such (13,512,3) codes. By applying a switching operation to those codes, two more (13,512,3) codes are obtained, which are then not doubly shortened perfect codes.Comment: v2: a correction concerning shortened codes of length 1

    Algebraic lattice constellations: bounds on performance

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    In this work, we give a bound on performance of any full-diversity lattice constellation constructed from algebraic number fields. We show that most of the already available constructions are almost optimal in the sense that any further improvement of the minimum product distance would lead to a negligible coding gain. Furthermore, we discuss constructions, minimum product distance, and bounds for full-diversity complex rotated Z[i]/sup n/-lattices for any dimension n, which avoid the need of component interleaving

    Walks of molecular motors in two and three dimensions

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    Molecular motors interacting with cytoskeletal filaments undergo peculiar random walks consisting of alternating sequences of directed movements along the filaments and diffusive motion in the surrounding solution. An ensemble of motors is studied which interacts with a single filament in two and three dimensions. The time evolution of the probability distribution for the bound and unbound motors is determined analytically. The diffusion of the motors is strongly enhanced parallel to the filament. The analytical expressions are in excellent agreement with the results of Monte Carlo simulations.Comment: 7 pages, 2 figures, to be published in Europhys. Let

    Collisional kinetics of non-uniform electric field, low-pressure, direct-current discharges in H2_{2}

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    A model of the collisional kinetics of energetic hydrogen atoms, molecules, and ions in pure H2_2 discharges is used to predict Hα_\alpha emission profiles and spatial distributions of emission from the cathode regions of low-pressure, weakly-ionized discharges for comparison with a wide variety of experiments. Positive and negative ion energy distributions are also predicted. The model developed for spatially uniform electric fields and current densities less than 10−310^{-3} A/m2^2 is extended to non-uniform electric fields, current densities of 10310^{3} A/m2^2, and electric field to gas density ratios E/N=1.3E/N = 1.3 MTd at 0.002 to 5 Torr pressure. (1 Td = 10−2110^{-21} V m2^2 and 1 Torr = 133 Pa) The observed far-wing Doppler broadening and spatial distribution of the Hα_\alpha emission is consistent with reactions among H+^+, H2+_2^+, H3+_3^+, and H−H^-H ions, fast H atoms, and fast H2_2 molecules, and with reflection, excitation, and attachment to fast H atoms at surfaces. The Hα_\alpha excitation and H−^- formation occur principally by collisions of fast H, fast H2_2, and H+^+ with H2_2. Simplifications include using a one-dimensional geometry, a multi-beam transport model, and the average cathode-fall electric field. The Hα_\alpha emission is linear with current density over eight orders of magnitude. The calculated ion energy distributions agree satisfactorily with experiment for H2+_2^+ and H3+_3^+, but are only in qualitative agreement for H+^+ and H−^-. The experiments successfully modeled range from short-gap, parallel-plane glow discharges to beam-like, electrostatic-confinement discharges.Comment: Submitted to Plasmas Sources Science and Technology 8/18/201

    Length of Aging has Greater Effect than Lactic Acid Treatment on Color Stability of Beef Chuck Muscles

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    Lactic acid spray washes are widely used as an antimicrobial intervention in the beef industry. Sprays are typically applied to the exterior of carcasses and subprimal cuts to reduce or eliminate potential pathogenic bacteria. While the efficacy of these washes has been proven, other questions remain about their effect on color attributes of meat when applied to subprimal cuts. The objective of this study was to determine the effect of a lactic acid subprimal wash on the color stability of beef chuck rolls
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