923 research outputs found

    Advances in microbial leaching processes for nickel extraction from lateritic minerals

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    Lateritic nickel minerals constitute about 80% of nickel reserves in the world, but their contribution for nickel production is about 40%. The obstacles in extraction of nickel from lateritic minerals are attributed to their very complex mineralogy and low nickel content. Hence, the existing metallurgical techniques are not techno-economically feasible and environmentally sustainable for processing of such complex deposits. At this juncture, microbial mineral processing could be a benevolent approach for processing of lateritic minerals in favor of nickel extraction. The microbial mineral processing route offers many advantages over conventional metallurgical methods as the process is operated under ambient conditions and requires low energy input; thus these processes are relatively simple and environment friendly. Microbial processing of the lateritic deposits still needs improvement to make it industrially viable. Microorganisms play the pivotal role in mineral bio-processing as they catalyze the extraction of metals from minerals. So it is inevitable to explore the physiological and bio-molecular mechanisms involved in this microbe-mineral interaction. The present article offers comprehensive information about the advances in microbial processes for extraction of nickel from laterites

    Spanning Tree Based Community Detection Using Min-Max Modularity

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    AbstractCommunity refers to the group of entities which have similar behavior or characteristic among them. Usually community represents basic functional unit of social network. By understanding the behavior of elements in a community, one can predict the overall feature of large scale social network. Social networks are generally represented in the form of graph structure, where the nodes in it represent the social entities and the edges correspond to the relationships between them. Detecting different communities in large scale network is a challenging task due to huge data size associated with such network. Community detection is one of the emerging research area in social network analysis.In this paper, a spanning tree based algorithm has been proposed for community detection which provides better performance with respect to both time and accuracy. Modularity is the well known metric used to measure the quality of community partition in most of the community detection algorithms. In this paper, an extensive version of modularity has been used for quality assessment

    Modelling and Simulation of Pseudolite-based Navigation: A GPS-independent Radio Navigation System

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    The use of global positioning system (GPS) for precision guidance of weapons is being questioned due to its vulnerability of jamming and spoofing for non-military code users. In this paper a novel approach is proposed for guidance of weapons where use of GPS or other civilian Satellite-based navigation system is threatened. The proposed approach is modelled and simulated using SIMULINK for realistic trajectories and scenario. The results of simulation are validated with the actual GPS data

    Control and analysis of crucial parameters for an automatic boiler unit in a chemical industry

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    A boiler plays a significant role in a processing industry, particularly in chemical industry. It requires proper adoption of control techniques for supplying accurate temperature, pressure, steam, and water flow to produce chemicals. An uncontrolled boiler can shut down the whole process. Therefore it requires a continuous monitoring system for avoiding such shutdown. In the past few decades, relay logic, embedded or process card systems were used for controlling the boiler system. In the conventional system, the controlling scheme was also complex for troubleshooting because process cards are used only once. In order to overcome this type of problem Supervisory Control and Data Acquisition (SCADA) and Programmable Logic Controller (PLC) system helps to collect data and information about the flow of boiler from various sensors. In this paper, SCADA and PLC assist in controlling crucial parameters using Proportional Integral Derivative (PID) control. PID controller used in this paper is programmed according to the boiler operation's need, and the data can be stored and analyzed using the SCADA system. The results in this paper help the industrial personnel for boiler automation, allowing the plant operator to observe the crucial parameters for increasing boiler efficiency and reducing the financial losses.&nbsp

    Analysis of Genetic Diversity among F4 segregating population of bitter gourd (Momordica charantia L.)

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    Seventeen breeding lines (ten F4 segregants and seven parents) of bitter gourd were evaluated at Department of Vegetable Science, OUAT, Bhubaneswar, during late kharif, 2022. These genotypes were used for evaluation of 13 quantitative characters which were grouped into five different clusters through Tocher’s method of genetic divergence analysis. Cluster I consists of ten genotypes, Cluster II, III and IV comprising of two genotypes each, while cluster V included only one genotype. Highest intra cluster distance was found in cluster IV (17.14) while lowest in cluster II (8.70). The highest inter cluster distance was observed between cluster III and V (26.18), followed by clusters I and V (25.06). For future breeding programme in bitter gourd, genotype of Cluster V should be selected for better vegetative growth, earliness in appearance of 1st female flower and giving yield for longer duration. Similarly, Cluster III for earliness in appearance of 1st male flower and more number of fruits vine-1 while that of cluster II should be considered for getting high yield with less number of seeds fruits-1. Seeds fruit-1 (61.03%) contributed maximum towards divergence followed by fruits vine-1 (12.50%)

    Mutual influence of structural distortion and superconductivity in systems with degenerate bands

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    The interplay between the band Jahn-Teller distortion and the superconductivity is studied for the system whose Fermi level lies in two-fold degenerate band. Assuming that the lattice distortion is coupled to the orbital electron density and the superconductivity arises due to BCS pairing mechanism between the electrons, the phase diagram is obtained for different doping with respect to half-filled band situation. The coexistence phase of superconductivity and distortion occurs within limited range of doping and the distortion lowers the superconducting transition temperature TcT_c. In presence of strong electron-lattice interaction the lattice strain is found to be maximum at half-filling and superconductivity does not appear for low doping. The maximum value of TcT_c obtainable for an optimum doping is limited by the structural transition temperature TsT_s. The growth of distortion is arrested with the onset of superconductivity and the distortion is found to disappear at lower temperature for some hole density. Such arresting of the growth of distortion at TcT_c produces discontinuous jump in thermal expansion coefficient. The variation of strain with temperature as well as with doping, thermal expansion coefficient, the TcT_c vs δ\delta behaviour are in qualitative agreement with recent experimental observations on interplay of distortion and superconductivity in cuprates.Comment: 15 pages Revtex style, 9 figures available on request to first Autho

    Ecological health assessment of a coastal ecosystem: Case study of the largest brackish water lagoon of Asia

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    This study focuses on the ecological health assessment of Chilika, a shallow lagoon present in east coast of India, through nutrient stoichiometry and trophic state index (TSI). Multivariate statistical analysis such as ANOVA, Pearson's correlation, Principal Component Analysis (PCA), and Discriminant Analysis (DA) were employed for data interpretation. Nutrient stoichiometry revealed that the Chilika Lagoon experiences phosphorus limitation with regard to nitrogen and silicate (N:P:Si = 16:1:16) throughout the study period. As per the computed TSI values, the southern sector (SS), central sector (CS), and outer channel (OC) were assigned with a mesotrophic status, whereas the northern sector (NS) was assigned with the eutrophic status. From PCA, total nitrogen was found to be negatively correlated with salinity and positively correlated with silicate, thus indicating that the major source of nitrogen in the lagoon was freshwater ingress by rivers with high silicate content. DA indicated that it was successful in discriminating the groups as predicted

    India’s contribution to mitigating the impacts of climate change through vegetation management

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    The changes in natural ecosystems provide opportunity to increase vegetation carbon sink capacity and thereby contribute to mitigation of climate change impacts. The Indian tropics and the large ecological variation within the country afford the advantage of diverse niches and offer opportunities to reveal the role of biotic factors at different levels of organization from populations to ecosystems. The last 4 decades of research and development in the Indian space science community has been primarily application driven in response to the government space programme for national development. The expenditure in R&D over next 5 year suggest that scientific research is higher on the country's agenda. The Indo-UK Terrestrial Carbon Group (IUTCG) comprising both Indian and UK scientists, funded jointly by the Department of Science and Technology, India and the Department of Business, Innovation and Skills organised a workshop to explore ways in which Earth observation data can be effectively utilised in mitigating the impacts of climate change through vegetation management. Effective integration of field observations, collected through various monitoring networks, and satellite sensor data has been proposed to provide country-wide monitoring

    Dynamical downscaling of austral summer climate forecasts over southern Africa using a regional coupled model

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    The prediction skill of dynamical downscaling is evaluated for climate forecasts over southern Africa using the Advanced Research Weather Research and Forecasting (WRF) model. As a case study, forecasts for the December–February (DJF) season of 2011/12 are evaluated. Initial and boundary conditions for the WRF model were taken from the seasonal forecasts of the Scale Interaction Experiment-Frontier Research Center for Global Change (SINTEX-F) coupled general circulation model. In addition to sea surface temperature (SST) forecasts generated by nine-member ensemble forecasts of SINTEX-F, the WRF was also configured to use SST generated by a simple mixed layer Price–Weller–Pinkel ocean model coupled to the WRF model. Analysis of the ensemble mean shows that the uncoupled WRF model significantly increases the biases (errors) in precipitation forecasted by SINTEX-F. When coupled to a simple mixed layer ocean model, the WRF model improves the spatial distribution of precipitation over southern Africa through a better representation of the moisture fluxes. Precipitation anomalies forecasted by the coupled WRF are seen to be significantly correlated with the observed precipitation anomalies over South Africa, Zimbabwe, southern Madagascar, and parts of Zambia and Angola. This is in contrast to the SINTEX-F global model precipitation anomaly forecasts that are closer to observations only for parts of Zimbabwe and South Africa. Therefore, the dynamical downscaling with the coupled WRF adds value to the SINTEX-F precipitation forecasts over southern Africa. However, the WRF model yields positive biases (>2°C) in surface air temperature forecasts over the southern African landmass in both the coupled and uncoupled configurations because of biases in the net heat fluxesThe Japan Science and Technology Agency (JST)/Japan International Cooperation Agency (JICA) through the Science and Technology Research Partnership for Sustainable Development (SATREPS).http://www2.ametsoc.org/ams/index.cfm/publications/journals/journal-of-climate/hb2016Geography, Geoinformatics and Meteorolog
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