Vignan University

About: Vignan University is a education organization based out in Guntur, Andhra Pradesh, India. It is known for research contribution in the topics: Computer science & Control theory. The organization has 1138 authors who have published 1381 publications receiving 7798 citations.

Quinazolin derivatives as emerging alpha-glucosidase inhibitors

Abstract: A series of C-7 substituted-2-morpholino- N -(pyridin-2-ylmethyl)quinazolin-4-amine have been synthesized and biochemical assay was examined against α-glucosidase function inhibition activity. A structure activity and structure property relationship study was experimented to surface the new hit compound. This study led to the identification of C-7substituted quinazolines with minimum inhibitory concentrations (MICs) in the preffered micromolar range in addition with interesting physicochemical properties. Biological evaluation yielded eight analogs which rose with significant α-glucosidase inhibition potency (IC 50 values < 2 μM, where reference compound (Acarbose) potency value is IC 50 = 0.586 uM) and could be promising candidates for further lead optimization.

Changes in depositional environment for the past 35 years in the Thane Creek, central west coast of India: inferences from REEs, metals and magnetic properties

Abstract: The role of diagenetic processes in influencing the behaviour of metals (Fe, Mn, Cu, Ni, Zn), rare earth elements (REEs) and environmental magnetic parameters in two sediment cores from a polluted creek environment (the Thane Creek, Mumbai) was investigated. The sediment age was determined using 210Pb analysis. Silty clays were dominant sediments in both the cores. Mineralogy showed the presence of quartz, calcite and plagioclase feldspar in bulk sediments, while smectite was the abundant clay mineral in the finer fraction. The mean ΣREE in both the cores was lower than in post-Archaean average Australian shale (PAAS). The PAAS-normalized REE patterns showed MREE and HREE enrichment with strong positive Eu and Y anomalies. The source rocks in the hinterland played an important role on the REE composition. Magnetic mineralogy showed dominance of magnetite. Both the cores showed low magnetic concentration of Al, Ti, Fe and Mn coinciding with high magnetic grain size at the middle portions. The early diagenetic changes at the middle portion of the cores were masked by significant abundance of clay content at the creek head and with OC and fine magnetite at the lower creek region. Metals (Cu, Ni, Zn; enrichment factor >1.5) and magnetic concentration in sediments were enriched in both the cores suggesting of an anthropogenic source.

Multi-criteria M-machine SDST flow shop scheduling using modified heuristic genetic algorithm

Abstract: The multi-criteria flow shop scheduling problem with sequence dependent setup times (SDST) is one of the most difficult class of scheduling problems. Efficient supervision of heuristics with SDST is one of the significant features to enhance the performance of manufacturing system. In this work, we have formulated multi-criteria decision-making flow shop scheduling problem. It consists of weighted sum of total weighted squared tardiness, makespan, total weighted squared earliness and number of tardy jobs. It is a very effective decision-making for scheduling jobs in modern manufacturing environment. In the present work, three efficient special heuristics based hybrid genetic algorithms (i.e., SHGA1, SHGA2, and SHGA3) are proposed for multi-criteria SDST. Experiments are conducted on the benchmark problems (Taillard, 1993). The performance of three SHGAs are tested, analysed and compared with the help of a defined performance index, known as relative percentage deviation (RPD). The maximum size of the problem is limited to 100 jobs and ten machines. From the results and analysis, the performance of SHGA3 found to be the best.

An Efficient Cache Refreshing Policy to Improve QoS in MANET Through RAMP

Abstract: Cache routing is an important phenomenon practiced in mobile ad hoc networks (MANET) to overcome the unnecessary process of route discovery, and overall, this route discovery process serves as a routing overhead. The concept of route cache is basically manipulated with the dynamic source routing (DSR) protocols with less percentage of QoS constraints. In this paper, a cache refreshing policy (CRP) is proposed to increase the overall QoS factors in MANET using reputation-aware multi-hop routing protocol (RAMP). RAMP basically provides secure and trusted access between nodes but fails in maintaining efficiency in QoS factors. In this paper, a challenging technique has been proposed to deal RAMP to work out with CRP to improve QoS.