360 research outputs found

    Blast Vibration Studies in Surface Mines

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    Blasting is very important process for mining operation and a lot of explosive is used for this purpose. The blasting process and usage of explosives, however, remain a potential source of numerous human and environmental hazards. Various studies indicate that fragmentation accounts for only 20-30% of the total amount of explosive energy used. Rest of the energy is lost in the form of ground vibration, fly rock, air overpressure and noise. The specific problem associated with ground vibrations represents the human response to them. Blasting vibrations may also cause a significant damage to nearby buildings or various structures. In this project blast vibration study is done and it is interpreted for its effects in reference to the standards set by DGMS. The study has been done with the help of geophones and Blastmate8.0 software. First of all the blasting operations were monitored through geophones at distances of 100m, 200m and 300m. The data obtained from the instrument were interpreted by Blastmate software and the graphical output was obtained from it. The Peak Particle Velocity (PPV), maximum charge per delay, air over pressure was recorded for each blast. After that the various observations were compared with the standards to determine the conclusion. From the analysis of blasts vibration at the mines it was determined that the vibration level was less than 5 mm/sec for the blasts when recommended amount of charge per delay or safe charge per delay was used. The air overpressure value determined was in between 114 & 127.6 dB (L). The results determined from the project indicates that the peak particle velocity, air overpressure generated due to blasting were within the limits. The safe charge per delay for the blasting operation was determined from the study

    Using HapMap data: a cautionary note

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    The HapMap data are being widely used in human genetic studies. We show by direct resequencing of a 6-kb region of chromosome 1 that the HapMap data are unreliable for this region. This region contains a recent mitochondrial (mt) DNA insertion. The HapMap data report the corresponding mtDNA variation and not the nuclear DNA variation. In view of mtDNA insertions of varying lengths throughout the human genome and considerable segmental duplications, it is necessary to use the HapMap data cautiously

    A Sparse Spike Deconvolution Algorithm Based on a Recurrent Neural Network and the Iterative Shrinkage-Thresholding Algorithm

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    Conventional sparse spike deconvolution algorithms that are based on the iterative shrinkage-thresholding algorithm (ISTA) are widely used. The aim of this type of algorithm is to obtain accurate seismic wavelets. When this is not fulfilled, the processing stops being optimum. Using a recurrent neural network (RNN) as deep learning method and applying backpropagation to ISTA, we have developed an RNN-like ISTA as an alternative sparse spike deconvolution algorithm. The algorithm is tested with both synthetic and real seismic data. The algorithm first builds a training dataset from existing well-logs seismic data and then extracts wavelets from those seismic data for further processing. Based on the extracted wavelets, the new method uses ISTA to calculate the reflection coefficients. Next, inspired by the backpropagation through time (BPTT) algorithm, backward error correction is performed on the wavelets while using the errors between the calculated reflection coefficients and the reflection coefficients corresponding to the training dataset. Finally, after performing backward correction over multiple iterations, a set of acceptable seismic wavelets is obtained, which is then used to deduce the sequence of reflection coefficients of the real data. The new algorithm improves the accuracy of the deconvolution results by reducing the effect of wrong seismic wavelets that are given by conventional ISTA. In this study, we account for the mechanism and the derivation of the proposed algorithm, and verify its effectiveness through experimentation using theoretical and real data

    Contrasting seed biology of two ornamental palms: Pygmy Date Palm (Phoenix roebelenii O’Brien) and Fishtail Palm (Caryota urens L.)

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    The Arecaceae family includes palm trees of economic importance both as a source of agricultural produce and asornamental components in landscaping projects. Pygmy date palm (Phoenix roebelenii) and solitary fishtail palm (Caryotaurens) are well known landscaping plants today. Both species have their origin in Southeast Asia and, especially C. urens iswidespread in peninsular India and Sri Lanka. They are multipurpose species with a variety of applications and thus veryheavily utilized. Knowledge of palm seed storage biology will improve their conservation prospects. In present studies, freshseed moisture content in P. roebelenii was recorded to be 30% with germinability of 98%. After desiccation to 8% moisturegerminability was reduced to 90% and the seeds survived cryo-exposure. Fresh seeds of C. urens, with initial moisturecontent of 34% and 95% germinability could be desiccated to lowest level of only 29% moisture content, with complete lossof germinability. Fresh as well as desiccated seeds of this species did not survive cryo-exposure. While the seeds of C. urensstored at room temperature lost their germinability by 110 days, seeds of P. roebelenii could germinate even after 9 monthsof storage. P. roebelenii is proven to exhibit orthodox seed storage behaviour while C. urens is found to exhibit recalcitrantseed storage behaviour. Long-term ex situ cryo-conservation in the form of seed gene banks would be suitable for seedpropagated orthodox palm species and a few germplasm centres may be established for recalcitrant Indian palms in suitablebio-geographic regions as a complimentary ex situ conservation

    Boswellia and Commiphora Species as a Resource Base for Rural Livelihood Security in the Horn of Africa: A Systematic Review

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    The dryland vegetation and particularly the Acacia-Commiphora woodlands support the livelihoods of approximately 52 million rural households in the Horn of Africa. Aromatic resins are valuable non-wood forest products (NWFPs) derived from Boswellia and Commiphora species in the drylands of this region. The study seeks to answer the following main questions: “What are the ecological and livelihood roles of resin producing species, and the role that people have in either degrading or restoring these ecosystems?” “Who are the participants in frankincense and myrrh production, processing, and trade, and how do these people interact?” “What is the current and potential future economic impact of frankincense and myrrh production and trade at the household level?” “What are the barriers to enhanced economic outcomes?” The study involves the use of PRISMA method—a systematic methodology to identify, select and analyze the recent literature on aromatic resins in relation to such factors as socio-economic situation, livelihood security, value chain, climate change adaptation, ecology and sustainable development in the Horn of Africa. Systematic identification of publications was conducted using several sources, including but not limited to electronic databases for literature search. Web of Science, Social Science Citation Index and Google Scholar and various scientific journals were investigated using search terms and restrictions. A total of 991 references were retrieved, but literature only published between 2003 to 2017 was selected, which led to the use of 51 works for full-text assessment. The results indicate that of the 51 selected studies, 45% focused on ecology and sustainable management, 31% on economic contribution and livelihood security, 20% on production and value chain development, and 4% on climate change adaptation and mitigation. It could be concluded that farmers’ adoption of Boswellia and Commiphora species as economic tree crops in the Horn of Africa has a distinct role in biodiversity conservation and climate change adaptation by contributing to the sustainability of ecosystem functioning as well as improving household incomes and the rural livelihood security in general, and thereby facilitating poverty alleviation

    Boswellia and Commiphora Species as a Resource Base for Rural Livelihood Security in the Horn of Africa: A Systematic Review

    Get PDF
    The dryland vegetation and particularly the Acacia-Commiphora woodlands support the livelihoods of approximately 52 million rural households in the Horn of Africa. Aromatic resins are valuable non-wood forest products (NWFPs) derived from Boswellia and Commiphora species in the drylands of this region. The study seeks to answer the following main questions: “What are the ecological and livelihood roles of resin producing species, and the role that people have in either degrading or restoring these ecosystems?” “Who are the participants in frankincense and myrrh production, processing, and trade, and how do these people interact?” “What is the current and potential future economic impact of frankincense and myrrh production and trade at the household level?” “What are the barriers to enhanced economic outcomes?” The study involves the use of PRISMA method—a systematic methodology to identify, select and analyze the recent literature on aromatic resins in relation to such factors as socio-economic situation, livelihood security, value chain, climate change adaptation, ecology and sustainable development in the Horn of Africa. Systematic identification of publications was conducted using several sources, including but not limited to electronic databases for literature search. Web of Science, Social Science Citation Index and Google Scholar and various scientific journals were investigated using search terms and restrictions. A total of 991 references were retrieved, but literature only published between 2003 to 2017 was selected, which led to the use of 51 works for full-text assessment. The results indicate that of the 51 selected studies, 45% focused on ecology and sustainable management, 31% on economic contribution and livelihood security, 20% on production and value chain development, and 4% on climate change adaptation and mitigation. It could be concluded that farmers’ adoption of Boswellia and Commiphora species as economic tree crops in the Horn of Africa has a distinct role in biodiversity conservation and climate change adaptation by contributing to the sustainability of ecosystem functioning as well as improving household incomes and the rural livelihood security in general, and thereby facilitating poverty alleviation

    Chemical and Physicochemical Pretreatment of Lignocellulosic Biomass: A Review

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    Overcoming the recalcitrance (resistance of plant cell walls to deconstruction) of lignocellulosic biomass is a key step in the production of fuels and chemicals. The recalcitrance is due to the highly crystalline structure of cellulose which is embedded in a matrix of polymers-lignin and hemicellulose. The main goal of pretreatment is to overcome this recalcitrance, to separate the cellulose from the matrix polymers, and to make it more accessible for enzymatic hydrolysis. Reports have shown that pretreatment can improve sugar yields to higher than 90% theoretical yield for biomass such as wood, grasses, and corn. This paper reviews different leading pretreatment technologies along with their latest developments and highlights their advantages and disadvantages with respect to subsequent hydrolysis and fermentation. The effects of different technologies on the components of biomass (cellulose, hemicellulose, and lignin) are also reviewed with a focus on how the treatment greatly enhances enzymatic cellulose digestibility

    Fundamental genomic unity of ethnic India is revealed by analysis of mitochondrial DNA

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    Mitochondrial DNA (mtDNA) profiles of 23 ethnic populations of India drawn from diverse cultural, linguistic and geographical backgrounds are presented. There is extensive sharing of a small number of mtDNA haplotypes, reconstructed on the basis of restriction fragment length polymorphisms, among the populations. This indicates that Indian populations were founded by a small number of females, possibly arriving on one of the early waves of out-of-Africa migration of modern humans; ethnic differentiation occurred subsequently through demographic expansions and geographic dispersal. The Asian-specific haplogroup M is in high frequency in most populations, especially tribal populations and Dravidian populations of southern India. Populations in which the frequencies of haplogroup M are relatively lower show higher frequencies of haplogroup U; such populations are primarily caste populations of northern India. This finding is indicative of a higher Caucasoid admixture in northern Indian populations. By examining the sharing of haplotypes between Indian and south-east Asian populations, we have provided evidence that south-east Asia was peopled by two waves of migration, one originating in India and the other originating in southern China. These findings have been examined and interpreted in the light of inferences derived from previous genomic and historical studies

    DNA sequence variation and haplotype structure of the ICAM1 and TNF genes in 12 ethnic groups of India reveal patterns of importance in designing association studies

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    We have examined the patterns of DNA sequence variation in and around the genes coding for ICAM1 and TNF, which play functional and correlated roles in inflammatory processes and immune cell responses, in 12 diverse ethnic groups of India. We aimed to (a) quantify the nature and extent of the variation, and (b) analyse the observed patterns of variation in relation to population history and ethnic background. At the ICAM1 and TNF loci, respectively, the total numbers of SNPs that were detected were 28 and 12. Many of these SNPs are not shared across ethnic groups and are unreported in the dbSNP or TSC databases, including two fairly common non-synonymous SNPs at positions 13487 and 13542 in the ICAM1 gene. Conversely, the TNF-376A SNP that is reported to be associated with susceptibility to malaria was not found in our study populations, even though some of the populations inhabit malaria endemic areas. Wide between-population variation in the frequencies of shared SNPs and coefficients of linkage disequilibrium have been observed. These findings have profound implications in case-control association studies
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