North Eastern Regional Institute of Science and Technology

About: North Eastern Regional Institute of Science and Technology is a education organization based out in Itanagar, India. It is known for research contribution in the topics: Population & Raman spectroscopy. The organization has 813 authors who have published 1429 publications receiving 16122 citations.

Study on Fabrication of Magnesium based Metal Matrix Composites and its improvement in Mechanical and Tribological Properties- A Review

Abstract: The present study, based on the literature review, reinforcing material, processing route, mechanical and tribological properties of Mg based metal matrix composites containing single and multiple reinforcement. Magnesium composites are new class metal matrix composites widely used in aerospace and automobile industries due to their low density, good mechanical properties, better corrosion and wear resistance, low thermal coefficient of expansion as compared to conventional metals and alloys. The performance of composites depends upon the right combination and composition of reinforcement material with the matrix material. This paper presents few of the available literature review the combination of reinforcement material with magnesium matrix metal. Magnesium metal matrix composites with reinforcement(s) and filler materials are finding increased applications because of improved mechanical and tribological properties. Addition of reinforcing materials such as Al2O3, SiC, B4C, metallic glass, etc., is one of the ways to enhance various mechanical and tribological properties of Mg based MMCs. When graphite is added composites decrease in tensile and hardness was observed whereas with graphite addition specific wear rate decreases. Waste materials may used as reinforcement such as fly ash, rice husk ash, etc. for low cost reinforcement which may results in better mechanical and wear properties.

Agroforestry systems as habitat for avian species: assessing its role in conservation.

Abstract: In the current scenario of rapid conversion of tropical forests into human-dominated activities landscape, the present study was undertaken to understand the role of existing agroforestry systems in conservation of avian species. Three types of agroforestry systems namely tea gardens, homegardens and agrisilviculture were selected in the Brahmaputra North Bank Landscape of Assam, northeast India for the study. A total of 468 point counts revealed 164 bird species belonging to 51 families and 18 orders across all the three different types of agroforestry systems. Tea gardens showed significantly higher bird species richness followed by homegardens and agrisilviculture systems. As per IUCN, four species were categorized as Near Threatened and one species was categorized as Vulnerable. Out of 164 species recorded, 68.3% species were residents, 30.5% species were winter visitors and remaining were summer visitors (1.2%). Majority of the species (45.7%) were common to all the three types of selected agroforestry systems. The feeding guilds revealed that most of the species were insectivorous (50.0%) in habit. A total of 167 tree species belonging to 54 families and 24 orders was recorded across all the three different types of agroforestry systems. The highest tree species richness was recorded in the homegardens (160), followed by agrisilviculture systems (19) and least in tea gardens (11). No statistically significant correlation was found among bird species richness and patch size, tree species richness and number of bird species individuals. The selected agroforestry systems have provided shelter, nesting space, feeding and foraging grounds for birds during the winter season. This data can be useful for the policy makers, tea garden managers, homegarden owners for framing conservation policies of avian species in an era of natural wildlife habitat loss and degradation.

Analysis of the effect of electric field due to High Voltage Transmission lines on humans

Abstract: The electromagnetic radiations from High Voltage Transmission lines are causing serious health threats to human beings working outdoors. Interference from HV lines may be electrostatic and electromagnetic interference. Probable risk for leukemia, neuropsychological disorders, cancer and reproductive outcomes has been reported due to this exposure. This paper is aimed at analysis of electric field distribution in a 400kV transmission line. Electric Field is calculated using FEM based ANSYS software package. By comparing these values with the standard available guidelines and the values calculated by analytical method we can find the permissible distance that the human beings may be exposed to.

A literature review on use of Bewley's lattice diagram

Abstract: Bewley's lattice diagram is a graphical method that has been widely used for determining value of a wave in transient analysis. This paper presents an extensive literature survey of previous publications in which Bewley's lattice diagram has been used for study of electromagnetic transients, fault location in distributed systems, calculation of transient fault currents n voltages in power system networks. From the survey, several observations can be made, such as on the purpose of analysis using this method and its advantages over the other methods. The paper also further discusses about the work done for computation with digital computer using spreadsheet and recursive algorithm method. The spreadsheet method is quite difficult to program using a high level language. The later method can be easily done with recursive algorithm and further work needs to be done in this direction.

Analysis of water distribution network under pressure-deficient conditions through emitter setting

Abstract: . Pressure-driven analysis (PDA) of water distribution networks necessitates an assessment of the supplying capacity of a network within the minimum and required pressure ranges. Pressure-deficient conditions happen due to the uncertainty of nodal demands, failure of electromechanical components, diversion of water, aging of pipes, permanent increase in the demand at certain supply nodes, fire demand, etc. As the demand-driven analysis (DDA) solves the governing equations without any bound on pressure head, it fails to replicate the real scenario, particularly when the network experiences pressure-deficient situations. Numerous researchers formulated different head–discharge relations and used them iteratively with demand-driven software, while some other approaches solve them by incorporating this relation within the analysis algorithms. Several attempts have been made by adding fictitious network elements like reservoirs, check valves (CVs), flow control valves (FCVs), emitters, dummy nodes and pipes of negligible length (i.e., negligible pressure loss) to assess the supplying capability of a network under pressure-deficient conditions using demand-driven simulation software. This paper illustrates a simple way of assessing the supplying capacity of demand nodes (DNs) under pressure-deficient conditions by assigning the respective emitter coefficient only for those nodes facing a pressure-deficit condition. The proposed method is tested with three benchmark networks, and it is able to simulate the network without addition of any fictitious network elements or changing the source code of the software like EPANET. Though the proposed approach is an iterative one, the computational burden of adding artificial elements in the other methods is avoided and is hence useful for analyzing large networks.