1,425 research outputs found

    Oxygen Isotopic Imaging of Refractory Inclusions from the Miller Range (MIL) 090019 CO3 Chondrite: A Perovskite Perspective

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    Calcium-Aluminum-rich Inclusions (CAIs) in primitive meteorites are the first solids to condense in the Solar System. The oxygen isotopic compositions recorded in various mineral components of CAIs provide clues about their origins and post-formation histories, recording processes such as condensation, melting, nebular alteration, and fluidrock reactions on the parent body. MIL 090019 is similar to some rare carbonaceous chondrites such as Acfer 094, DOM 08004/6 and ALH 77303 that contain high abundances of a variety of refractory inclusions. This provides an opportunity to study the oxygen isotopic record of different types of refractory inclusions within the same meteorite. We analyzed CAIs specifically targeting primary minerals that are direct nebular condensates, such as corundum and perovskite, with the goal of gaining insights into the O isotopic composition of the nebular gas(es) from which these CAIs condensed. As MIL 090019 is a classified as CO3.1, it shows some signs of thermal metamorphism, compared to the more primitive CO3 meteorites (e.g., DOM 08004/06). A second goal of this study is to search for evidence of nebular processes in phases such as perovskite and melilite that are susceptible to parent body alteration to varying degrees. We analyzed the oxygen isotopic compositions of various CAIs from the MIL 090019 CO3 carbonaceous chondrite by ion imaging using the NanoSIMS 50L (Nano Secondary Ion Mass Spectrometer) at JSC following methods described in. An advantage of ion imaging over traditional spot analyses is that it provides spatial context to the oxygen isotopic data. This work builds on previously reported oxygen isotopic composition of two other CAIs (CAI-44 and CAI-E2) from the same meteorite thin section

    Isotopic and Microstructural Analyses of Opaque Mineral Assemblages and Their Alteration Products Hosted in a Refractory Inclusion

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    Calcium-aluminum-rich inclusions (CAIs) hosted in primitive meteorites are the oldest solids formed in the Solar System. Some CAIs contain metal nuggets that are complex assemblages of Fe-Ni alloys, along with rare ultra-refractory metals such as platinum group elements (PGEs), and their alteration products such as magnetite, sulfides, and phosphates. Three possible mechanisms proposed to explain the origin of these metal nuggets include condensation in circumstellar settings, condensation in the solar nebula within the CAI-forming region, or crystallization from immiscible metal-silicate melt. However, secondary alteration processes may have also affected some of these assemblages. Additionally, similar metal assemblages observed in chondrules and chondritic matrix indicate that all of these metal nuggets could share common high-temperature origins. These metal assemblages record early Solar System conditions that are reflected in their distinctive chemical composition, mineralogy and microstructures. Here we report a detailed mineralogical, microstructural and oxygen isotopic study of one such metal assemblage hosted in a CAI to understand the physical and chemical settings in which it formed

    Watermarking and Cryptography Based Image Authentication on Reconfigurable Platform

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    Now-a-days, multimedia based applications have been developed rapidly. Digital information is easy to process but it allows illegal users to access the data. For protecting the data from this illegal use, Digital Rights Management (DRM) can be used. DRM allows secure exchange of digital data over internet or other electronic media. In this paper, FPGA based implementation of DWT alongwith Advanced Encryption Standard (AES) based watermarking is discussed. With this approach, improved security can be achieved. The complete system is designed using HDL and simulated using Questasim and MATLAB Simulink model. The synthesis result shows that this implementation occupies only 2117 slices and maximum frequency reported for this design is 228.064 MHz

    Paillier based Privacy-Preserving Mining of Association Rules from Outsourced Transaction Databases

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    The Cloud computing is computing in which massive assembling of remote servers are managed to authorized centralized data storage and online access to computer resources , while Privacy-preserving data mining (PPDM) is one of the latest inclination in privacy and security studies. It is determined by one of the important positioning issues of the information era - the right to privacy. With the use of cloud computing services, an organization lack in computational resources can deploy its mining requires to an outsider service provider. However, both the elements and the association rules of the deployed database are observed as private property of the organization. The data owner converts its data and sends it to the server, ships mining queries to the server, and recoup the actual design from the extricate designs received from the outsider server for corporate privacy prevention. In this theory, we study the problems of outsourcing the association rule mining mechanisms within a corporate privacy-preserving framework. The Rob Frugal method is founded with defeat the security obligations of outsourced data. This method is an encryption plan which is based on one to one substitution ciphers for items and fake pattern from the database. In this system attacker discovers data by guessing attack, also man in the middle attack which is possible on Rob Frugal encryption to conquer this problem, the proposed technique encompasses Paillier encryption for enhancing the security level for outsourced data with the less complexity and to protect against the forging the contents of the correspondence. FP-growth algorithm is used for generating association rules for improving the performance and for preserving a homomorphic encryption algorithm Paillier cryptosystem is being used

    General consideration of Pakshaghata and its management using natural medicine and Ayurveda principles

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    Pakshaghata (Hemiplegia) is one of the most common causes of death especially in elder age group. Pakshaghata mainly occurs due to the obstruction of cerebral blood vessels, ischemia, and lack of glucose metabolism and weakness of nerve cell. Loss of movement, sensory deficit, dysarthria, atrophy, stiffness and disturbed nerve impulses are the major symptoms of disease. Ayurveda offers various treatment modalities for the management of Pakshaghata such as; use of herbs & formulation, yoga and Shodhana Chikitsa. Present article described various approaches of ayurveda for the management of Pakshaghata including natural herbs and Shodhana Chikitsa

    Review of optimal design of composite structures under uncertainty

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    This study represents optimization of hollow circular, rectangular and airfoil composite beam by using sub problem approximation method in ANSYS. A three dimensional static analysis of large displacement type has been carried out for hollow circular, rectangular and airfoil composite beams. Weight of beam was objective function, material parameter, geometrical, ply thickness, ply angles and load. In order to validate the results, one loop of simulation is benchmarked from results in literature. Ultimately, best set of optimized design variable is proposed to reduce weight under static loading condition

    Trace Element Abundances in an Unusual Hibonite-Perovskite Refractory Inclusion from Allende

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    Calcium-aluminum-rich refractory inclusions (CAIs) are thought to be the first-formed solids in the Solar protoplanetary disk and can provide information about the earliest Solar System processes (e.g., [1]). A hibonite-perovskitebearing CAI from the Allende CV3 chondrite (SHAL, [2]) contains a single of 500 micrometers hibonite grain and coarse-grained perovskite. The mineralogy and oxygen isotopic composition of this CAI shows similarities with FUN inclusions, especially HAL [2]. Here we present trace element abundances in SHAL

    A Comprehensive Study on Modelling and Control of Autonomous Underwater Vehicle

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    Autonomous underwater vehicles (AUV) have become the de facto vehicle for remote operations involving oceanography, inspection, and monitoring tasks. These vehicles operate in different and often challenging environments; hence, the design and development of the AUV involving hydrodynamics and control systems need to be designed in detail. This book chapter presents a study on the modelling and robust control of a research vehicle in the presence of uncertainties. The vehicle's dynamic behaviour is modelled using a 6-degree-of-freedom approach, considering the effect of ocean currents. The level flight requirements for different speeds are derived, and the resulting model is decomposed into horizontal and vertical subsystems for linear analysis. The simulation results presented focus on the efficacy of linear controllers within three key subsystems: depth, yaw, and speed. Moreover, level-flight outcomes are demonstrated for a speed of 4 knots. The nonlinear control strategies employed in this study encompass conventional and sliding-mode control (SMC) methodologies. To ensure accurate tracking performance, the controller design considers the vehicle's dynamics with various uncertainties such as ocean currents, parameter uncertainty, CG (Center of Gravity) deviation and buoyancy variation. Both conventional and nonlinear SMC controllers' outcomes are showcased with a lawn-mowing manoeuvre scenario. A systematic comparison is drawn between the robustness of SMC against disturbances and parameter fluctuations in contrast to conventional controllers. Importantly, these results underscore the trade-off that accompanies SMC's robustness, as it necessitates a higher level of complexity in terms of controller design, intricate implementation intricacies, and the management of chattering phenomena.Comment: Accepted for publication in Assistive Robotics, CRC Press, Taylor & Francis, USA. This is the preprint version of the book chapte

    An Assessment of Accessibility and Connectivity of Some Important Places in Kolhapur City of Maharashtra: A Road Network Analysis

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    There are various methods to find out the accessibility and connectivity of road networks. The method that used to determine the accessibility and connectivity is quantitative or qualitative; sometime it includes both quantitative and qualitative aspects of transportation network. The degree to which any place is served by transportation network (on which it stands) defines the accessibility of that place. And the connectivity is the ratio between total number of arcs and total number of nodes in transportation network. The connectivity is directly proportional to the total number of arcs and inversely proportional to the total number of nodes. If the degree of connectivity within a transportation network is higher; then it means that transportation system will be more efficient. Therefore, the present paper attempts to access the accessibility and connectivity of road networks in Kolhapur city. The accessibility of study area is determined by the shortest path matrix. The connectivity is determined by the beta (?) index given by K.J. Kansky. After analyzing the accessibility and connectivity of study area, easily accessible and shortest paths are also suggested in order to reach the important centers very easily

    PRESERVATION OF PANEER BY USING PVC CLING FILM

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    Paneer is a popular indigenous variety of soft cheese in India and used as a base material for the preparation of a large number of culinary dishes. Paneer, like other indigenous products is highly ±perishable. At room temperature it cannot be stored more than a day and under refrigeration it may remain acceptable for six days. Therefore, study was undertaken to give a comprehensive package by application of sorbic acid and PVC cling film. It is observed that paneer could be stored safely up to 13 days at 7±ºC by adapting hygienic practices of manufacturing and wrapping during it in PVC cling film. Use of 0.1% sorbic acid alone could be recommended along with wrapping of paneer in cling film to extend its storage life up to 33 days in refrigeration (7±ºC ) and for 3 days at room temperature. There was reduction in moisture content but rise in titratable acidity, FFA, peroxide value and soluble nitrogen in treated paneer during storage at both the temperatures.Â
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