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.

Characteristics of Electronegative Plasma Sheath with q-Nonextensive Electron Distribution

Abstract: The characteristics of sheath in a plasma system containing q-nonextensive electrons, cold fluid ions, and Boltzmann-distributed negative ions are investigated. A modified Bohm sheath criterion is derived by using the Sagdeev pseudopotential technique. It is found that the proposed Bohm velocity depends on the degree of nonextensivity (q), negative ion temperature to nonextensive electron temperature ratio (σ), and negative ion density (B). Using the modified Bohm sheath criterion, the sheath characteristics, such as the spatial distribution of the potential, positive ion velocity, and density profile, have been numerically investigated, which clearly shows the effect of negative ions, as well as the nonextensive distribution of electrons. It is found that, as the nonextensivity parameter and the electronegativity increases, the electrostatic sheath potential increases sharply and the sheath width decreases.

Nucleophilic ring-opening of iron(III)-hydroxy-isoporphyrin.

Abstract: The reactions of iron(III) hydroxyisoporphyrin, chloro[5-(hydroxy)-5,10,15,20-tetrakis(4-methyl)-5,21H-porphinato]iron(III) [Fe(4-Me-HTPI)(Cl)](-), 1 and chloro[5-(hydroxy)-5,10,15,20-tetrakis(4-methoxy-5,21H-porphinato]iron(III) [Fe(4-OMe-HTPI)(Cl)](-), 2 with different O(-), N(-) and S(-) nucleophiles have been performed to understand the reactivity of iron isoporphyrins with nucleophiles. The treatment of iron(III) hydroxy isoporphyrin with alcohols is found to form ring opened 19-benzoyl-1-alkoxy-bilin iron complexes. When alkyl amines were used the formation of ring opened 19-benzoyl-1-alkylamine-bilin iron complexes was observed, but heterocyclic N-nucleophiles such as pyridine and imidazole form benzoyl bilinone iron complexes. No role of oxygen was found in these nucleophilic ring opening reactions. The treatment of a S-nucleophile such as PhSH is found to reduce iron(III)-hydroxyisoporphyrin in the parent iron(III) porphyrin compound. The ring opening products were characterized using electronic and ESI-mass spectroscopy. The mechanism for the formation of ring opening products is based on the formation of a tetrahedral intermediate at the carbon atom near the saturated meso carbon atom similar to the hydrolytic pathway of verdoheme conversion to biliverdin.

A novel wide & deep transfer learning stacked GRU framework for network intrusion detection

Abstract: With the increasing frequency, severity and complexity of recent cyber attacks around the world, network intrusion detection has become mandatory and highly sophisticated task. Achieving high performance in network intrusion detection by applying benchmark machine learning classifiers (including deep learning techniques) has become a major challenge in recent times. One of the biggest challenges is improving the memorization capacity and generalization ability of NIDS (Network Intrusion Detection Systems). In this paper, we propose a highly scalable novel wide & deep transfer learning (TL) based stacked GRU (Gated Recurrent Unit) model to deal with multi-dimensional point data and multi-variate time series regression and classification problems in network intrusion detection. The proposed model has the memorization capacity of linear regression model and the generalization ability of deep GRU model. The deep component consists of a transfer learning framework that pretrains a source model and then fine-tunes the whole source model on the same dataset multiple times until it gives peak performance. This method gives a multi-class evaluation accuracy of 99.92% on KDDCup 99(10%) dataset and 94.22% on UNSW-NB15 dataset respectively. Extensive experimentations and evaluations have been carried out by comparing it with other machine learning (including deep learning) network intrusion detection techniques. The proposed method outperforms most of the existing intrusion detection approaches.

Surge Modelling of Transformer Using Matlab-Simulink

Abstract: -This paper aims to validate the surge modelling of a transformer using Matlab-Simulink using an electromagnetic model and thereby ascertaining the model accuracy. The studies cover winding responses to both full and chopped standard lightning impulses with time to chop varying over a wide range. Modelling was carried out using the design data of a 3 MVA, 33/11 kV, 3-phase, 50 Hz, Dyn 11 Transformer whose 33 kV mesh connected winding was considered to be subjected to standard full wave (1.2/ 50 μs) and chopped impulses chopped at 3 μs, 8 μs and 15 μs. The mathematical model considered takes into account the series and shunt capacitances and inductances of the winding elements, including the effect of their mutual inductances. The Simulation compared with the experimental results shows the validity of the Surge modelling of the transformer. Keywords - Modelling, Lightning Surges, Transformer winding, Transients.I. INTRODUCTION n a power system a power transformer is the most important and expensive piece of equipment. The fundamental work on transients in a magnetic winding was done by Wagner [1] 1915. Great progress has been made since 1915 in understanding the physical phenomenon which govern the transient response in transformer. Required transformer insulation is determined to a great extent by the transient voltages and stresses which appear in the transformer winding. Varying impulse voltages with long wave shape and large magnitude may be due to switching fault, lightning surge or by commercial impulse voltage test in the laboratory [2]. To design the insulation it is necessary to know the voltage appearing across the insulation (as a function of time) and the strength of insulation against the particular voltage wave. The study of the behaviour of a transformer winding with one grounded end is done when stressed by standard impulse voltage wave (1.2/50 μs) and chopped impulse waves chopped at 3 μs, 8 μs and 15 μs [2]. II. MODEL PARAMETERS The Transformer winding is represented by a network with distributed parameters as shown in Fig. 1. C, K, L and M represent the capacitance to ground, series capacitance, self inductance and mutual inductance per unit winding length respectively. Magnetic losses have been ignored [2, 3, 4].