National Institute of Technology, Silchar

About: National Institute of Technology, Silchar is a education organization based out in Silchar, Assam, India. It is known for research contribution in the topics: Control theory & Electric power system. The organization has 1934 authors who have published 4219 publications receiving 41149 citations. The organization is also known as: NIT Silchar.

Adsorptive desulfurization of feed diesel using chemically impregnated coconut coir waste

Abstract: This study reports the usage of chemically impregnated coconut coir waste (CICCW) as a low-cost adsorbent for the desulfurization of feed diesel. The characterization of the developed adsorbent was focused on quantitative analysis (carbon yield %, proximate, ultimate, carbon surface functionalities, BET surface area and porosity distribution, and particle size analysis), qualitative analysis (FTIR), and optical analysis (SEM). Batch experiments with feed diesel having a total sulfur concentration of 2,050 mg L−1 were conducted to optimize the adsorption parameters such as adsorbent dose, temperature, and contact time. The adsorption process shows an optimum dose of 1 g/20 mL, and the equilibrium is attained in 3 h. The adsorption of sulfur onto the adsorbent at optimum temperature 293 K is regulated by external mass transfer (diffusion into mesopores) followed by a steady adsorption phase with intra-particle diffusion in micropores. A Fickian mechanism controls the diffusion of sulfur molecules from the solution onto the surface of the adsorbent. Freundlich adsorption isotherm illustrates the equilibrium adsorption data very well. The negative value of ΔG° (−27.61 kJ mol−1) and ΔS° (−44.56 J K−1 mol−1) indicates the feasibility, spontaneity of the adsorption process and justified the decrease in the randomness of adsorbed sulfur molecules onto the adsorbent surface, respectively. The exhausted CICCW can be effectively regenerated by methanol and reutilized for three adsorption–desorption cycles. The approximate cost of preparation of the adsorbent was USD 10.714 per kg. These results clearly proved the feasibility of the developed low-cost adsorbent (CICCW) as a good candidate for the desulfurization of feed diesel.

Gap acceptance behavior of drivers at uncontrolled T-intersections under mixed traffic conditions

Abstract: Explicit traffic control measures are absent in uncontrolled intersections which make them susceptible to frequent conflicts and resulting collisions between vehicles. In developing countries like India, drivers at such intersections do not yield to higher priority movements which cause more crashes between vehicles. The objective of this study is to analyze and model the gap acceptance behavior of minor street drivers at uncontrolled T-intersections considering their aggressive nature. Three intersections in the northeast region of India have been selected as the case study area. Preliminary analysis of the data revealed that drivers behave aggressively, not because they have to wait for a long time at the stop line, but because of their lack of respect for traffic rules. Binary logit models are developed for minor road right turning vehicles which show that gap acceptance behavior is influenced by gap duration, clearing time and aggressive nature of drivers. The equations obtained were used to estimate the critical gaps for aggressive and non-aggressive drivers. Critical gaps are also calculated using an existing method called clearing behavior approach. It is also shown that the estimation of critical gap is more realistic if clearing time and aggressive behavior of drivers are considered.

A new secure authentication scheme for cloud computing environment

Abstract: Summary Cloud computing is an emerging computing area that allows on-demand, scalable, flexible, and low-cost services to the users. In cloud computing, access control and security are two major problems. In this paper, a novel authentication scheme using Chebyshev chaotic maps has been presented. The proposed model satisfies many security factors, such as scalability of login, mutual authentication, freedom of password change, two-factor security, and forward security. Two-factor security is a method that requires two credentials for authentication, where the first factor may be something that users know and the second factor may be something that users have. Forward security assures the confidentiality of the user's session key, even if the private key of the server is compromised. In addition, the proposed scheme provides users with untraceability and anonymity, which means that any kind of adversary neither gets the identities of users or servers nor link several sessions with a user or server. The proposed model is secured under the computational Diffie–Hellman assumption of Chebyshev polynomials in the random oracle model. Moreover, security and performance analysis show that the proposed scheme can resist different security attacks in cloud computing environment and it is better than existing schemes. Copyright © 2016 John Wiley & Sons, Ltd.

Correlating slump, slump flow, vebe and flow tests to rheological parameters of high-performance concrete

Abstract: Conventional single-point workability tests continue to be used for specification and quality control of concrete despite their inherent limitations. These tests cannot characterize workability of concrete in terms of fundamental rheological parameters. Attempt has therefore been made to correlate slump, slump flow, slump flow time, percent flow and Vebe time to rheological parameters of high-performance concrete. Thirty numbers of concrete mixes without steel fibers and with steel fibers of specific dose have been considered during experiment. It has been observed that rheological parameters can be correlated to slump and slump flow. In case of fiber reinforced concrete, there is a decrease in percent flow with the increase in rheological parameters. Vebe time, however, remains unchanged up to yield stress 500 Pa and plastic viscosity 40 Pa.s beyond which it steeply increases with further increase in yield stress and plastic viscosity. Flow test may be a better test for FRC as it is sensitive over all ranges of workability of concrete.