18 research outputs found

    Dynamic phase-encoding storage of 64 images in a BaTiO3 photorefractive crystal

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    Storage of 64 images (128 x 128 pixels) by the deterministic phase-encoding technique in a holographic memory is reported. A ferroelectric phase modulator permits a fast random image reconstruction (150 As/image). Sources of cross talk arising from the imperfections of the optical components are studied and evaluated. We present a photorefractive (PR) memory setup that permits the storage of N = 64 images of 128 X 128 binary pixels in a BaTiO3 crystal by the deterministic phase-encoding technique.`-4 Because of the absence of any moving mechanical parts this multiplexing method permits a reliable and very fast random access to the images. This memory could be used in digital computing or for pattern recognition.' This technique consists of recording the N images by interference of the image beam with all N reference beams. These beams are angularly spaced by more than the Bragg angle so that each of them reconstruct

    Haemoglobin and potassium polymorphism in agro-pastoral goats herd from Sudan savannah zone of Nigeria

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    This study was conducted to determine the haemoglobin (Hb) and potassium (K) polymorphism and its distribution in agro-pastoral goats herd of Sudan savanna zone of Nigeria. Five (5l) ml of blood samples were collected each from 250 smallholder agropastoral goats and used for this study. The blood samples were collected by jugular venipuncture, using needle and syringe into test tube containing ethylene diamine tetra acetic acid (EDTA) as anticoagulant and samples were properly labeled. The electrophoretic analysis showed three haemoglobin genotypes HbAA, HbAB and HbBB. These genotypes were produced by 2 co-dominant alleles HbA and HbB. The genotypic frequencies were 0.47, 0.43 and 0.099 for HbAA, HbAB and HbBB, respectively. The preponderance of HbA alleles (0.683) was twice its co-dominant allele HbB (0.316). The Chi-square test revealed that the population of goats in the study area was in Hardy- Weinberg equilibrium. The gene frequencies of potassium polymorphism were 0.844 and 0.156 for high (HK) and low potassium (LK) types, respectively. The genotypic frequencies were 0.91 for HK and 0.01 for LK in the overall population. The observedfrequencies of potassium types were also in Hardy-Weinberg equilibrium in both locations and in the overall population. thus suggesting that random mating occurred for the system under study and artificial selection has not much been practiced by the smallholder agro-pastoral goats farmers in the study area.Keywords: Haemoglobin, Potassium, Polymorphism, Agro-pastoral, Goats, Genotypes, Dominant allele, Hardy-Weinberg equilibriu
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