Synthesis and Characterization of Alumina/Iron Oxide Mixed Nanocomposite

The Aluminium & Iron oxides mixed nanocomposites have been prepared by hydrothermal as well as combustion synthesis process. The resulting composite has been characterized by using the XRD, FE-SEM, FT-IR, and BET analytical techniques. From X –ray diffraction (XRD) analysis, it is clearly observed that the composite synthesized by hydrothermal method has α-Fe2O3 and y-AlO(OH) crystalline phase where as α-Fe2O3 and α–Al2O3 phase has been found in combustion synthetic method. The FE-SEM analysis indicates that the formation of needle shaped particles for hydrothermal synthesis where as the porous & flake like morphology is found in case of combustion synthesis. The SEM-EDAX (Elemental detection x-ray analysis) results suggest the presence of Al, Fe & O elements in the alumina/iron oxide mixed composites. The FT-IR analysis indicates the formation of α-Fe2O3 and y-AlO(OH) in hydrothermal synthesis. The BET study suggests that the mixed composites synthesized by hydrothermal method are nonporous in nature and the surface area is found to be 35 m2/gm. The results of combustion synthesis illustrate that the fuel to oxidizer ratio is the most effective factor for the formation & surface morphology of mixed nanocomposite

Chemical Reaction and Radiation Effect on MHD Flow Past an Exponentially Accelerated Vertical Plate in Presence of Heat Source with Variable Temperature Embedded in a Porous Medium

In this paper we analyse the effect of chemical reaction and radiation on MHD fluid flow through a porous medium in a uniform magnetic field with variable temperature and mass diffusion with heat source past an exponentially accelerated vertical plate. The non-dimensional equations governing the above flow characteristics are solved by using Laplace Transformation and the effect of different physical parameters on the velocity profile, temperature profile and concentration profile are illustrated graphically.  Keywords: Variable temperature, heat source, radiation, porous medium

Signature of a silver phase percolation threshold in microscopically phase separated ternary Ge0.15Se0.85-xAgx (0 <= x <= 0.20) glasses

Temperature modulated Alternating Differential Scanning Calorimetric (ADSC) studies show that Se rich Ge0.15Se0.85-xAgx (0 <= x <= 0.20) glasses are microscopically phase separated, containing Ag2Se phases embedded in a Ge0.15Se0.85 backbone. With increasing silver concentration, Ag2Se phase percolates in the Ge-Se matrix, with a well-defined percolation threshold at x = 0.10. A signature of this percolation transition is shown up in the thermal behavior, as the appearance of two exothermic crystallization peaks. Density, molar volume and micro-hardness measurements, undertaken in the present study, also strongly support this view of percolation transition. The super-ionic conduction observed earlier in these glasses at higher silver proportions, is likely to be connected with the silver phase percolation.Comment: 4 pages, 7 figure

Key Predistribution Schemes in Distributed Wireless Sensor Network using Combinatorial Designs Revisited

A Sensor Node in Wireless Sensor Network has very limited resources such as processing capability, memory capacity, battery power, and communication capability. When the communication between any two sensor nodes are required to be secured, the symmetric key cryptography technique is used for its advantage over public key cryptography in terms of requirement of less resources. Keys are pre-distributed to each sensor node from a set of keys called key pool before deployment of sensors nodes. Combinatorial design helps in a great way to determine the way keys are drawn from the key pool for distributing to individual sensor nodes. We study various deterministic key predistribution techniques that are based on combinatorial design

A Deterministic Approach of Merging of Blocks in Transversal Design based Key Predistribution

Transversal Design is a well known combinatorial design that has been used in deterministic key predistribution scheme. Merging of blocks in a design sometimes helps to obtain a key predistribution scheme with better performance. A deterministic merging strategy to merge the blocks has been discussed. Also, a simple key establishment method for transversal design based key predistribution scheme has been discussed

Weakness of Key Predistribution Scheme Proposed by J. Dong et al.

A Sensor Node in Wireless Sensor Network has very limited resources such as processing capability, memory capacity, battery power, and communication capability. When the communication between any two sensor nodes are required to be secured, the symmetric key cryptography technique is used for its advantage over public key cryptography in terms of requirement of less resources. Keys are pre-distributed to each sensor node from a set of keys called key pool before deployment of sensors nodes. Combinatorial design helps in a great way to determine the way keys are drawn from the key pool for distributing to individual sensor nodes. J. Dong et al proposed a key predistribution scheme based on orthogonal array. We present the weakness of this predistribution scheme

Chaos and Quantum-Classical Correspondence via Phase Space Distribution Functions

Quantum-classical correspondence in conservative chaotic Hamiltonian systems is examined using a uniform structure measure for quantal and classical phase space distribution functions. The similarities and differences between quantum and classical time-evolving distribution functions are exposed by both analytical and numerical means. The quantum-classical correspondence of low-order statistical moments is also studied. The results shed considerable light on quantum-classical correspondence.Comment: 16 pages, 5 figures, to appear in Physical Review

Identification of antisense nucleic acid hybridization sites in mRNA molecules with self-quenching fluorescent reporter molecules

We describe a physical mRNA mapping strategy employing fluorescent self-quenching reporter molecules (SQRMs) that facilitates the identification of mRNA sequence accessible for hybridization with antisense nucleic acids in vitro and in vivo, real time. SQRMs are 20–30 base oligodeoxynucleotides with 5–6 bp complementary ends to which a 5′ fluorophore and 3′ quenching group are attached. Alone, the SQRM complementary ends form a stem that holds the fluorophore and quencher in contact. When the SQRM forms base pairs with its target, the structure separates the fluorophore from the quencher. This event can be reported by fluorescence emission when the fluorophore is excited. The stem–loop of the SQRM suggests that SQRM be made to target natural stem–loop structures formed during mRNA synthesis. The general utility of this method is demonstrated by SQRM identification of targetable sequence within c-myb and bcl-6 mRNA. Corresponding antisense oligonucleotides reduce these gene products in cells