Informatics Publishing Limited

Asit Baran Mandal ¹, S. Vellaichamy ¹, Jilly James ¹, Ramya S. G. Krishnan ¹, S. Govindarajan ²

Affiliations
1 Chemical Laboratory, Physical and Inorganic Chemistry Division, Central Leather Research Institute, Adyar, Chennai 600 020, IN
2 Department of Chemistry, Loyola College, Chennai 600 034, IN

Abstract

The hydration of the polymer micelles has been directly determined from the measurements of conductance of micellar solutions of the triblock copolymer (PEO-PPO-PEO) in 25 mM SDS (fixed) and in 5 mM NaCl (fixed), using the principle of the obstruction of electrolyte migration by the polymer. The asymmetry of the micellar entities of the polymer and the polymer-SDS mixed micellar systems and their average axial ratios are calculated using the intrinsic viscosity and hydration data obeying Simha-Einstein equation. The hydration of the polymer has also been determined by Einstein and Vand equations, and good agreement with the conductivity results obtained. Hydration number and micellar sizes are found to be variable with temperature. The aggregation number, ̅N of the polymer in an aqueous solution of SDS (25 mM, fixed) was determined by fluorescence spectroscopic technique considering the SDS solution as the solvent only in one case, and in the other case, the micellar concentration of SDS had been taken into account to consider the SDS-polymer mixed system. Both ̅N and the Stern-Volmer constant (K_sv) are variable with temperature. The shape of the polymer micelles has been observed to be ellipsoidal rather than spherical. From the absolute values of the axes, the micellar volume, hydrodynamic radius, radius of gyration, diffusional coefficients as well as translational (τ_D), rotational (τ_r) and effective (τ_a) correlation times have been calculated. The partial molal volume of the polymer micelles has also been determined and its comparison with the molar volume of the pure polymer suggested a volume contraction due to the immobilization of the water phase by the hydrophilic head groups of the polymer. The thermodynamic activation parameters for the viscous flow favour a more ordered water structure around the polymer micelles at higher temperatures.

Keywords

Geometry of the Micelles, Triblock Copolymer, Mixed Micelles, Aggregation, Correlation Times and Thermodynamic Parameters.

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R. Thenmozhi ¹, S. Govindarajan ², F. EzhilMaryArasi ¹

Affiliations
1 SRM University, Chennai, IN
2 Department of Computer Application, SRM University, Chennai, IN

Abstract

A Wireless Sensor Network (WSN) consists of spatially distributed autonomous sensors to cooperatively monitor physical or environmental conditions. Providing end-to-end data security in wireless sensor network (WSN) is a non-trivial task. In addition to the large number and severe resource constraint of sensor nodes, a particular challenge comes from potential insider attacks due to possible node compromise, since a WSN is usually deployed in unattended/hostile environments. Compromised node and denial of service are two key attacks in Wireless Sensor Network (WSN). Here, we study the data delivery mechanisms to overcome these attacks with high probability of circumventing black holes. Classic multipath routing approaches are vulnerable to such attacks, mainly due to their deterministic nature. Once the adversary acquires the routing algorithm, it can compute the same routes known to the source and make all information sent over these routes vulnerable to its attacks. In this paper, we develop mechanisms that generate randomized multipath routes. Under our designs, the routes taken by the “shares” of different packets change over time. So even if the routing algorithm becomes known to the adversary, the adversary still cannot pinpoint the routes traversed by each packet. Besides randomness, the generated routes are also highly dispersive and energy efficient, making them quite capable of circumventing black holes.

Keywords

Black Holes, Randomized Multipath Routes, Secure Data Collection, Wireless Sensor Network.

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K. M. Uma Maheswari ¹, S. Kanchana Devi ¹, S. Govindarajan ¹

Affiliations
1 Department of MCA, SRM University, Chennai, IN

Abstract

The basic role of a wireless sensor network is to collect information from the environment by many sensor nodes (SNs). The SN typically has a finite battery life and nodes' failures can lead to network partition. Therefore, it is important to minimize the energy usage of each sensor node and to manage the power of SN in critical position that their failure could divide the network. This drives research on how to design routing protocols to gather data efficiently, so that the life of the network can be prolonged. A usual concept to collect data by a sink node is to transfer data from sensor nodes to the sink node by multi-hop. To resolves the problems, a new energy balanced and efficient data aggregation scheme for WSN is used. With a predetermined set of paths based on the specific Application.

Keywords

DD, DP, HDA, WSN, RTABLE.PLIST, TPL.

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Spoorthy N. Babu ¹, S. Govindarajan ¹, M. A. Vijayalakshmi ¹, Ayesha Noor ¹

Affiliations
1 Centre for Bio Separation Technology (CBST), Vellore Institute of Technology (VIT), Vellore, Tamil Nadu,-632 014, IN

Abstract

Aloe vera (Aloe barbadensis Miller) is a perennial succulent plant belonging to the Aloeaceae family and has been used for many centuries for its medicinal properties. Among the Aloe vera plant parts, gel is being widely studied for their biological properties. However, epidermis and flowers are neglected and are not probed for their importance. In this study, the methanolic extracts of Aloe vera gel, leaf and flower were evaluated for their anti-oxidant and anti-diabetic potential in vitro and other phytochemical constituents. We observed that the Aloe vera gel, leaf and flowers have shown significant anti-oxidant potential. When compared between leaf, gel and flower of Aloe vera, the leaf showed better antioxidant activity in ABTS, DPPH, H₂O₂ radical scavenging activities, Metal chelating activity and reducing power. However, the gel extract showed better anti-diabetic efficacy compared to the flower extract with respect to α-amylase, α-glucosidase, DPP-IV inhibition and anti-glycation activities. This study suggests that different parts of Aloe vera exhibit great potential for antioxidant and anti-diabetic activity and may be useful in new health-care food supplements or nutraceutical.

Keywords

?Aloe vera, Gel, Epidermis, Flower, Phenolic Compounds, Antioxidant, Antidiabetic.

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