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Efficient procedure of mono, Di and Tri substituted amidines from amides using AlMe3
( Shanmugavel Ramachandran ),이상협 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.1
Organo-aluminum motifs are more significant reagents due to their low cost, high selectivity and considerable stabilities. Owing to these advantages of organo-aluminum moiety, it has been applied in various organic transformations. Traditionally, garigipati introduced AlMe3 in the synthesis of unsubtititued amidines from nitriles and later by many others. We herein report the simple procedure for synthesis of mono, di and tri substituted amidines from primary, secondary and tertiary amides.
( Shanmugavel Ramachandran ),이상협 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.1
Quinoxaline derivatives exhibit a wide range of biological functions including various antibiotics such as Echinomycin, Levomycin and Actinoleutin that are known to inhibit growth of gram positive bacteria and are active against various transplantable tumours. Initially, ethyl 2-(2-azidophenylamino)-2-oxoacetate, which was previously obtained from the coupling reaction between ethyl 2-chloro-2-oxoacetate and azidoaniline was subjected to N-alkylation with various alkylating agents in presence of LiHMDS. Then, these alkylated products were cyclized by the treatment of TPP to yield corresponding 3-amino-1-quinoxalin- 2 (1H)-ones via Staudinger reaction followed by aza-Wittig reaction, which can be finally derivatized by Lewis acid mediated smart cleavage.
NIA based Mobility Management Technique for Seamless Roaming in Heterogeneous Networks
Sivakami Thiyagarajan,Shanmugavel Sedhu 보안공학연구지원센터 2014 International Journal of Future Generation Communi Vol.7 No.6
Heterogeneous networks are composed of different access technology together to provide Always Best Connected services in anywhere at any time. In such environment mobility is the major issue. Existing mobility support protocols like MIPv6, HMIPv6 and FMIPv6 are performing low during vertical handoff process. To improve QoS performances and to interconnect different networks, an agent called NIA (network interworking agent) and multiple IGMA (interworking gateway mobility agent) has been deployed. The UDP and TCP simulation results are obtained using NS2 environment and compared with an existing macro mobility protocols.
G. Padmavathi,S. Shanmugavel 보안공학연구지원센터 2014 International Journal of Future Generation Communi Vol.7 No.6
Cognitive Radio (CR) is a novel technology that can improve the utilization efficiency of the radio spectrum and also address the spectrum scarcity problem by opportunistically using the unused channels (spectrum holes / white spaces) in the Licensed Spectrum of Primary Users. Spectrum sensing is the primary function of CR which determines the spectrum holes for opportunistic usage by Secondary Users. Spectrum sensing plays a critical role in Cognitive Radio. The development of a reliable and accurate spectrum sensing is very essential to propound quick and accurate detection of white spaces for better throughput of Secondary User network under the constraint of the specified Primary System protection. In this paper, a Cooperative Spectrum Sensing using Wavelet Denoising along with Soften Hard Decision technique has been proposed to improve the performance of spectrum sensing. Simulation result shows an improvement of nearly 15% in the Probability of Missed Detection for a target Probability of False Alarm of 0.1 and SNR of -10 dB. Also 50% improvement in error probability has been achieved with 1-D one level wavelet denoising.
Radha, Sankararajan,Shanmugavel, Sethu The Korea Institute of Information and Commucation 2003 Journal of communications and networks Vol.5 No.3
The central challenge in the design of ad-hoc networks is the development of dynamic routing protocol that efficiently finds route between mobile nodes. Several routing protocols such as DSR, AODV and DSDV have been proposed in the literature to facilitate communication in such dynamically changing network topology. In this paper, a Node Transition Probability (NTP) based routing algorithm, which determines stable routes using the received power from all other neighboring nodes is proposed. NTP based routing algorithm is designed and implemented using Global Mobile Simulator (GloMoSim), a scalable network simulator. The performance of this routing algorithm is studied for various mobility models and throughput, control overhead, average end-to-end delay, and percentage of packet dropped are compared with the existing routing protocols. This algorithm shows acceptable performance under all mobility conditions. The results show that this algorithm maximizes the bandwidth utilization during heavy traffic with lesser overhead.
V. Babu,Balasivanandha Prabu Shanmugavel,K. A. Padmanabhan 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.10
The influence of the semi-die angle (α = 45°, 30° and 22.5°employed in the present experiments) of the cyclic expansion extrusion (CEE) process on grain refinement in Al-alloy AA 6063 processed at 100°C at a pressing velocity of 0.5 mm.s− 1 and subjected to different number of passes is examined. The strain imparted on the specimen strongly depends on the die geometry. Grain refinement as well as increase in the ultimate tensile strength and micro-hardness after 10 CEE passes is the highest when the semi-die angle (α) is 22.5°. TEM images reveal the formation of fine grains after 10 CEE passes. Dislocation generation and cell formation directly depend on the strain imparted and the interactions between the dislocations and the Mg2Si precipitates. The tensile strength and hardness of the CEE processed specimens were compared as a function of the semi-die angle (α) and the results were compared with those of the unprocessed alloy also.
V. Babu,Balasivanandha Prabu Shanmugavel,K. A. Padmanabhan 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.8
The influence of working temperature and number of passes on the mechanical properties of aluminium alloy, AA 5083,processed by cyclic expansion and extrusion (CEE) is discussed. The specimens were processed up-to 10 CEE passes at200 °C, 300 °C and 400 °C. The average grain size of the starting annealed material was 84.5 ± 6.8 μm, with 39.4% beingof the high-angle grain boundaries (HAGBs) type. After 8 CEE passes at 200 °C the material had an average grain size of3.3 ± 0.6 μm and 41.3% of the grain boundaries were of the high-angle type (HAGBs). The combined effect of an increasein dislocation density and reduction in grain size as a result of CEE processing contributed to an increase in hardness andstrength of the alloy. At 200 °C, the specimen exhibited uniform hardness values with a maximum improvement of 104% after8 passes and the ultimate tensile strength had also increased by 64% compared with the unprocessed condition. However,the mechanical properties decreased in the specimens that were processed at the higher temperatures of 300 °C and 400 °C.
Rajan John,Gaur Girwar Singh,Shanmugavel Karthik,S Adinarayanan 대한약리학회 2024 The Korean Journal of Physiology & Pharmacology Vol.28 No.3
Chronic neuropathic pain (CNP) is a complex condition often arising from neural maladaptation after nerve injury. Understanding CNP complications involves the intricate interplay between brain-heart dynamics, assessed through quantitative electroencephalogram (qEEG) and heart rate variability (HRV). However, insights into their interaction in chronic pain are limited. Resting EEG and simultaneous electrocardiogram (lead II) of the participants were recorded for qEEG and HRV analysis. Correlations between HRV and qEEG parameters were calculated and compared with age, sex, and body mass index (BMI)-matched controls. CNP patients showed reduced HRV and significant increases in qEEG power spectral densities within delta, theta, and beta frequency ranges. A positive correlation was found between low frequency/ high frequency (LF/HF) ratio in HRV analysis and theta, alpha, and beta frequency bands in qEEG among CNP patients. However, no significant correlation was observed between parasympathetic indices and theta, beta bands in qEEG within CNP group, unlike age, sex, and BMI-matched healthy controls. CNP patients display significant HRV reductions and distinctive qEEG patterns. While healthy controls exhibit significant correlations between parasympathetic HRV parameters and qEEG spectral densities, these relationships are diminished or absent in CNP individuals. LF/HF ratio, reflecting sympathovagal balance, correlates significantly with qEEG frequency bands (theta, alpha, beta), illuminating autonomic dysregulation in CNP. These findings emphasize the intricate brain-heart interplay in chronic pain, warranting further exploration.