91 research outputs found

    Non Oblivious Watermarking Technique for JPEG2000 Compressed Images Using Arnold Scrambling of Unequal Size Watermark Blocks

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    In this paper, a watermarking technique for JPEG2000 compressed image is proposed. Scrambling of secret message is performed block-wise using Arnold Transform. Secret message is divided into non-overlapping blocks of unequal size and then Arnold transform is applied on each block and secret key is generated based on the periodicity of each block. Scrambled secret message is embedded into qualified significant wavelet coefficients of a cover image. After embedding the secret message into wavelet coefficients, the remaining processes of JPEG2000 standard are executed to compress the watermarked image at different compression rates. Scaling Factor (SF) is used to embed watermark into wavelet coefficients and the value of SF is stored into COM box of the code stream of JPEG2000 compressed image and this SF value and secret key are used to extract the embedded watermark on the receiver side. The performance of the proposed technique is robust to a variety of attacks like image cropping, salt and pepper noise, and rotation. Proposed technique is compared with the existing watermarking techniques for JPEG2000 compressed images to show its effectiveness

    Bit Plane Coding Based Steganography Technique for JPEG2000 Images and Videos

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    In this paper, a Bit Plane Coding (BPC) based steganography technique for JPEG2000 images and Motion JPEG2000 video is proposed. Embedding in this technique is performed in the lowest significant bit planes of the wavelet coefficients of a cover image. In JPEG2000 standard, the number of bit planes of wavelet coefficients to be used in encoding is dependent on the compression rate and are used in Tier-2 process of JPEG2000. In the proposed technique, Tier-1 and Tier-2 processes of JPEG2000 and Motion JPEG2000 are executed twice on the encoder side to collect the information about the lowest bit planes of all code blocks of a cover image, which is utilized in embedding and transmitted to the decoder. After embedding secret data, Optimal Pixel Adjustment Process (OPAP) is applied on stego images to enhance its visual quality. Experimental results show that proposed technique provides large embedding capacity and better visual quality of stego images than existing steganography techniques for JPEG2000 compressed images and videos. Extracted secret image is similar to the original secret image

    Modelling and simulation of a solar absorption cooling system for India

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    This paper presents modelling and simulation of a solar absorption cooling system. In this paper, the modelling of a solar-powered, single stage, absorption cooling system, using a flat plate collector and water–lithium bromide solution, is done. A computer program has been developed for the absorption system to simulate various cycle configurations with the help of various weather data for the village Bahal, District Bhiwani, Haryana, India. The effects of hot water inlet temperatures on the coefficient of performance (COP) and the surface area of the absorption cooling component are studied. The hot water inlet temperature is found to affect the surface area of some of the system components. Moreover the effect of the reference temperature which is the minimum allowable hot water inlet temperature on the fraction of total load met by non-purchased energy (FNP) and coefficient of performance (COP) is studied and it is found that high reference temperature increases the system COP and decreases the surface area of system components but lower reference temperature gives better results for FNP than high reference temperatures

    Conservation and Diversity of Seed Associated Endophytes in Zea across Boundaries of Evolution, Ethnography and Ecology

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    Endophytes are non-pathogenic microbes living inside plants. We asked whether endophytic species were conserved in the agriculturally important plant genus Zea as it became domesticated from its wild ancestors (teosinte) to modern maize (corn) and moved from Mexico to Canada. Kernels from populations of four different teosintes and 10 different maize varieties were screened for endophytic bacteria by culturing, cloning and DNA fingerprinting using terminal restriction fragment length polymorphism (TRFLP) of 16S rDNA. Principle component analysis of TRFLP data showed that seed endophyte community composition varied in relation to plant host phylogeny. However, there was a core microbiota of endophytes that was conserved in Zea seeds across boundaries of evolution, ethnography and ecology. The majority of seed endophytes in the wild ancestor persist today in domesticated maize, though ancient selection against the hard fruitcase surrounding seeds may have altered the abundance of endophytes. Four TRFLP signals including two predicted to represent Clostridium and Paenibacillus species were conserved across all Zea genotypes, while culturing showed that Enterobacter, Methylobacteria, Pantoea and Pseudomonas species were widespread, with Îł-proteobacteria being the prevalent class. Twenty-six different genera were cultured, and these were evaluated for their ability to stimulate plant growth, grow on nitrogen-free media, solubilize phosphate, sequester iron, secrete RNAse, antagonize pathogens, catabolize the precursor of ethylene, produce auxin and acetoin/butanediol. Of these traits, phosphate solubilization and production of acetoin/butanediol were the most commonly observed. An isolate from the giant Mexican landrace Mixteco, with 100% identity to Burkholderia phytofirmans, significantly promoted shoot potato biomass. GFP tagging and maize stem injection confirmed that several seed endophytes could spread systemically through the plant. One seed isolate, Enterobacter asburiae, was able to exit the root and colonize the rhizosphere. Conservation and diversity in Zea-microbe relationships are discussed in the context of ecology, crop domestication, selection and migration

    Isolation of a Psychrotrophic Exiguobacterium sp. SKPB5 (MTCC 7803) and Characterization of Its Alkaline Protease

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    Out of nine psychrotrophic bacterial strains isolated from cold environments of the Western Himalayas, SKPB5 was selected for protease purification and characterization because it had the largest zone of clearance on plate assay. On the basis of the phenotypic and biochemical characterization and 16S rRNA gene-sequencing studies, isolate was identified as Exiguobacterium sp. SKPB5. The protease was purified near to homogeneity with a purification fold of 7.1, and its molecular weight was determined to be 36 kDa. The enzyme exhibited maximum stability at 50 degree C and an optimal pH of 8.0. Metal ions Mg2+, Ca2+, Zn2+, and Mn2+ enhanced the enzyme activity, whereas Cu2+ had no effect. Phenylmethanesulfonyl fluoride and ethylenediaminetetraacetic acid did not show any effect on the activity of the enzyme, whereas a 20% increase in activity was observed when it was incubated in presence of reducing agents such as b-mercaptoethanol and dithiothreitol. This suggests that the protease isolated from psychrotrophic Exiguobacterium sp. SKPB5 belongs to the cysteine family. The results highlight the relevance of unexplored microbes from cold environments of Western Himalayas for the isolation of protease enzymes active at wide range of temperature and pH

    Modelling and simulation of a solar absorption cooling system for India

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    This paper presents modelling and simulation of a solar absorption cooling system. In this paper, the modelling of a solar-powered, single stage, absorption cooling system, using a flat plate collector and water–lithium bromide solution, is done. A computer program has been developed for the absorption system to simulate various cycle configurations with the help of various weather data for the village Bahal, District Bhiwani, Haryana, India. The effects of hot water inlet temperatures on the coefficient of performance (COP) and the surface area of the absorption cooling component are studied. The hot water inlet temperature is found to affect the surface area of some of the system components. Moreover the effect of the reference temperature which is the minimum allowable hot water inlet temperature on the fraction of total load met by non-purchased energy (FNP) and coefficient of performance (COP) is studied and it is found that high reference temperature increases the system COP and decreases the surface area of system components but lower reference temperature gives better results for FNP than high reference temperatures

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    Not AvailableFive plant pathogenic fungi were isolated from infected plants of groundnut, castor and cumin growing under arid environment. The isolates belonged to two fungal genera and were identified as Alternaria tenuissima (CZC-2), Alternaria alternata (CZCU-1), Fusarium equiseti (CZCU-2), Fusarium oxysporum (CZCU-4) and Fusarium solani (CZGN-9) based on ribosomal DNA sequencing. The effect of copper oxide nanoparticles on growth inhibition of these fungal pathogens was carried out in solid and liquid media. In the plate method A. tenuissima (CZC-2) showed the maximum diameter of colony growth in control plates in both the media, whereas the minimum diameter of colony growth was shown by Alternaria tenuissima CZC-2 and Fusarium solani CZGN-9 in the potato dextrose agar (PDA) and rose bengal agar (RBA) supplemented with 500 ppm of copper oxide nanoparticles (CNP), respectively. In the plate method the maximum inhibition of 68.8 % was reported against A. tenuissima CZC-2 in plates supplemented with 500 ppm of copper nanoparticles. Whereas in liquid medium there was complete growth inhibition of A. tenuissima CZC-2 and F. oxysporum CZCU-4 at 250 ppm concentration of copper oxide nanoparticles.Not Availabl

    Isolation and identification of a psychrotrophic Acinetobacter sp CR9 and characterization of its alkaline lipase

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    Forty three psychrotrophic bacteria were isolated from soil samples collected from Chandra river in sub-alpine region of western Himalaya, India. Among these, 11 isolates were found positive for lipase production at low temperature. Of 11 isolates, CR9 produced largest zone of clearance on plate assay and was able to produce lipase under wide range of pH. The isolate CR9 was identified as Acinetobacter sp. based on morphological and physiochemical characterization and 16S rRNA gene sequencing analysis. According to 16S rRNA gene sequencing data the closest phylogenetic neighbor for strain CR9 was Acinetobacter lwoffii (98.9%). The partially purified lipase from strain CR9 exhibited maximum activity at temperature 40 C and pH optima at 8.0. Cu2+, Mo2+, Mg2+, Zn2+, phenylmethanesulfonyl fluoride (PMSF), dithiothreitol (DTT) and beta-mercaptoethanol (2-ME) enhanced the enzyme activity, whereas Ca2+ and ethylene-diaminetetraacetic acid (EDTA) had inhibitory effect. Lipase hydrolyzed wide range of short chain fatty acid esters of p-nitrophenyl. The organism CR9 also hydrolyzed tributyrin, Tween 80, soybean oil, mustard oil and olive oil. The results highlight the relevance of unexplored microbes from cold environments of western Himalaya for the isolation of novel lipase producing bacteria

    Microbial proteases: Detection, production, and genetic improvement

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    Microbial proteases are one of the important groups of industrially and commercially produced enzymes contributing approximately 2/3 of all enzyme sales. Though proteases are produced by many microorganisms, emphasis is on the microorganisms producing proteases with desired characters. As demand for novel proteases is increasing day by day the initial screening methods and assays for protease detection are of utmost importance. This review focuses attention on present status of knowledge on the various methods and protocols available for protease screening, detection, and quantification starting from plate assays to spectrophotometric, fluorometric, and nanoparticles based assays. The review will help in making strategies for exploitation of protease resources and improvement of enzymes to obtain more robust proteases
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