Informatics Publishing Limited

C. Balaji ¹, C. Krishnamoorthy ¹, R. Chandrasekar ¹

Affiliations
1 Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600 036, IN

Abstract

In this study, ab initio atmospheric profiles generated through high-resolution calculations from the community weather model WRF, suitably matched up with both TRMM Microwave Imager (TMI) and Precipitation Radar (PR) instruments of the TRMM satellite were used to compute simulated brightness temperatures (BTs) corresponding to SAPHIR frequencies, through an in-house polarized radiative transfer code. An artificial neural network was then constructed and trained to return the near-surface rain (NSR) rate given the six BTs corresponding to SAPHIR. For accomplishing the retrievals, measured BTs of SAPHIR (level 1 data) were used. NSR rates were calculated for two precipitating systems, namely (i) cyclone Neelam and (ii) cyclone Phailin. Rain rates thus estimated were then validated with the TMI-PR combined rain product of TRMM (2A12). The results showed that there is good agreement between the two. An inter-comparison between rain rates derived from MADRAS and SAPHIR was also done. This unexpected ability of the SAPHIR radiances provide us with the rainfall signature opens up new vistas in achieving the mission objectives of Megha-Tropiques.

Keywords

Brightness Temperatures, Megha-Tropiques, Neelam, Phailin, SAPHIR.

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Viswanathan Pachaiyappan ¹, R. Chandrasekar ¹

Affiliations
1 Department of Computer Science and Engineering, Dr. Mahalingam College of Engineering and Technology, Pollachi, Tamil Nadu, IN

Abstract

Cloud computing has recently reached popularity and developed into a major trend in IT world. Several challenges are being raised from the adoption of this computational paradigm including security and privacy. Identity Management (IDM) is one of the core components in cloud privacy and security which can ease some of the problems associated with cloud computing. Users must provide sensitive information i.e., Personally Identifiable Information (PII) which uniquely identifies them, to authenticate to Cloud Service Providers (CSPs) in order to get the requested service. However, users can still experience privacy infringement because users cannot have direct control over the exchange of PII between CSPs. The approach proposed in this paper preserves the privacy in identity management. The technique is based on Zero Knowledge Proof of Knowledge (ZKPK) where a user is authenticated to CSP without disclosing PII. Once a user is authenticated, user releases appropriate PII based on computed trust level of CSP. Thereafter, CSP provides requested service to user.

Keywords

Cloud Computing, Identity Management, Privacy, Personally Identifiable Information (PII), Zero Knowledge Proof of Knowledge (ZKPK).

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S. Sathish Kumar ¹, G. Melchias ¹, P. Ravikumar ², R. Chandrasekar ³, P. Kumaravel ⁴

Affiliations
1 Department of Botany, St. Joseph’s College (Autonomous), Tiruchirappalli, Tamil Nadu, IN
2 Govt. Arts College (Autonomous), Coimbatore, Tamil Nadu, IN
3 Institute of Forest Genetics and Tree Breeding, Coimbatore, Tamil Nadu, IN
4 Department of Biotechnology, Vysya College, Salem, Tamil Nadu, IN

Abstract

Development of reliable green synthesis of silver nanoparticles by various plants and microorganisms has been reported in many research aspects. However, the probable of plants as natural materials for the synthesis of nanoparticles and their compatibility to biological systems is yet to be fully explored. In this study, we report a simple green method for the synthesis of silver nanoparticles using Euphorbia hirta (E. hirta) leaves extract as a reducing and stabilizing agent. After exposing the silver ions to E. hirta leaves extract, rapid reduction of silver ions is observed leading to the formation of silver nanoparticles in solution. The synthesized nanoparticles were characterized by using UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), Field emission Scanning Electron Microscopy (FESEM) and Particle size analysis. The synthesized silver nanoparticles show maximum zone of inhibition against Bacillus subtilis, Vibrio cholera and Salmonella typhi.

Keywords

Silver Nanoparticles, E. hirta, Antimicrobial Activity.

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