Elastic properties of As-Sb-Se glasses

Results of measurement of elastic modulii on As-Sb-Se glasses are reported and their composition dependence discussed. The Young’s and the shear modulii lie in the range of 170–210 and 65–80 kb respectively. These values are typical of chalcogenide glasses. For (As, Sb)₄₀Se₆₀ glasses, the modulii increase monotonically with increasing Sb₂Se₃ content. The observed composition dependence of the modulii for the As _x Sb₁₅Se_{85 −x} glasses is examined in terms of the chemically ordered structural units in the glasses.     

Development of electromagnetic shielding materials from the conductive blends of polyaniline and polyaniline-clay nanocomposite-EVA: Preparation and properties

Electromagnetic interference shielding composite materials were developed from the conductive blends of nanostructured polyaniline (PANI) and polyaniline-clay nanocomposite (PANICN) with ethylene vinyl acetate (EVA) as host matrix. Electrically conducting nanostructured PANI and PANICNs were prepared using amphiphilic dopants, 3-pentadecyl phenol 4-sulphonic acid (3-PDPSA) derived from cashew nut shell liquid, a low cost renewable resource based product and dodecyl benzene sulfonic acid (DBSA). Effects of type and quantity of conductive fillers on the electrical conductivity, mechanical properties, thermal stability, morphology and electromagnetic shielding efficiency were investigated. The presence of exfoliated nanoclay and interaction between the conductive filler–host matrix in conductive films containing PANICNs manifested from the measurement on rheological property. Films with conductive filler (～15% loading) showed a shielding effectiveness of ～40–80 dB at 8 GHz which makes these conducting composites potential candidate for the encapsulation as EMI shielding materials for electronic devices.     

Complex methylene-blue-sensitized polyvinyl chloride: a polymer matrix for hologram recording

A new polymer matrix sensitized with methylene blue for use as an optical recording material is described here. The characterization is done to determine the optimal recording conditions. These films need no chemical development and are found to be stable for several months. The matrix has excellent shelf life and needs an exposure only as short as 20 s. Direct imaging was done on this material.     

Chemical bath deposition of different phases of copper selenide thin films by controlling bath parameters

In the preparation of copper selenide thin films using chemical bath deposition (CBD) technique, it is observed that the pH of the final reacting mixture is the major factor controlling the composition of the film. Thin films of cubic Cu_2−xSe and tetragonal Cu₃Se₂, of band gaps 2.20 and 2.83 eV, respectively, have been prepared using the CBD technique by adjusting the bath parameters like pH, temperature and the ratio between copper and selenium atoms in the reaction bath. X-ray diffraction analysis is used as the major tool for identification of these phases. The results have been confirmed using XPS, ICP and absorption studies.     

Removal of Pb(II) ions from aqueous solution by adsorption using bael leaves (Aegle marmelos)

Biosorption of Pb(II) on bael leaves (Aegle marmelos) was investigated for the removal of Pb(II) from aqueous solution using different doses of adsorbent, initial pH, and contact time. The maximum Pb loading capacity of the bael leaves was 104 mg g^?1 at 50 mg L^?1 initial Pb(II) concentration at pH 5.1. SEM and FT-IR studies indicated that the adsorption of Pb(II) occurs inside the wall of the hollow tubes present in the bael leaves and carboxylic acid, thioester and sulphonamide groups are involved in the process. The sorption process was best described by pseudo second order kinetics. Among Freundlich and Langmuir isotherms, the latter had a better fit with the experimental data. The activation energy E_a confirmed that the nature of adsorption was physisorption. Bael leaves can selectively remove Pb(II) in the presence of other metal ions. This was demonstrated by removing Pb from the effluent of exhausted batteries.     

Equivalence of classicality and separability based on P phase–space representation of symmetric multiqubit states

Classical and quantum world views differ in peculiar ways. Understanding decisive quantum features—for which no classical explanation exist—and their interrelations is of foundational interest. Moreover, recognizing non-classical features carries practical significance in information processing tasks as it offers insights as to why quantum protocols work better than their classical counterparts. We focus here on two celebrated notions of non-classicality viz., negativity of P phase–space representation and entanglement in symmetric multiqubit systems. We prove that they imply each other.     

An enhanced encryption algorithm for video based on multiple Huffman tables

Encryption is one of the fundamental technologies that is used in the security of multimedia data. Unlike ordinary computer applications, multimedia applications generate large amount of data that has to be processed in real time. This work investigates the problem of efficient multimedia data encryption. A scheme known as the Randomized Huffman Table scheme was recently proposed to achieve encryption along with compression. Though this scheme has several advantages it cannot overcome the chosen plaintext attack. An enhancement of this Huffman scheme is proposed in this work which essentially overcomes the attack and improves the security. The proposed encryption approach consists of two modules. The first module is the Randomized Huffman Table module, the output of which is fed to the second XOR module to enhance the performance. Security analysis shows that the proposed scheme can withstand the chosen plaintext attack. The efficiency and security of the proposed scheme makes it an ideal choice for real time secure multimedia applications.     

Nonclassical dynamics with time- and intensity-dependent coupling

Nonclassical light and collapse-revival dynamics are consequences of dynamical quantum interference in transient photon-atom interaction. We study the time evolution of atom and photons in a high quality cavity for time-dependent atom-field coupling, with different initial field states and initial atomic states. The inversion for initial superposed atomic state seems to be independent of initial classical fields but can be stimulated by the Schrodinger cat field. Interesting effects of the transient coupling are found through analysis of the collapse-revival in population inversion and the features in the Wigner function. Oscillatory coupling coefficient can prolong the occurrence of collapse, in analogy to the Zeno effect. The intensity atom-field coupling duration is an important parameter for controlling atomic inversion and producing frozen nonclassical light in the cavity after the atom-field coupling ceases.     

Novel optimized tree-based stack-type architecture for 2n-bit comparator at nanoscale with energy dissipation analysis

Comparator is an essential building block in many digital circuits such as biometric authentication, data sorting, and exponents comparison in floating-point architectures among others. Quantum-dot Cellular Automata (QCA) is a latest nanotechnology that overcomes the drawbacks of Complementary Metal Oxide Semiconductor (CMOS) technology. In this paper, novel area optimized 2n-bit comparator architecture is proposed. To achieve the objective, 1-bit stack-type and 4-bit tree-based stack-type (TB-ST) comparators are proposed using QCA. Then, two tree-based architectures of 4-bit comparators are arranged in two layers to optimize the number of quantum cells and area of an 8-bit comparator. Thus, this design can be extended to any 2n-bit comparator. Simulation results of 4-bit and 8-bit comparators using QCADesigner 2.0.3 show that there is a significant improvement in the number of quantum cells and area occupancy. The proposed TB-ST 8-bit comparator uses 2.5 clock cycles and 622 quantum cells with area occupancy of 0.49 µm² which is an improvement by 10.5% and 38%, respectively, compared to existing designs. Scaling it to a 32-bit comparator, the proposed architecture requires only 2675 quantum cells in an area of 2.05 µm² with a delay of 3.5 clock cycles, indicating 9.35% and 28.8% improvements, respectively, demonstrating the merit of the proposed architecture. Besides, energy dissipation analysis of the proposed TB-ST 8-bit comparator is simulated on QCADesigner-E tool, indicating average energy dissipation reduction of 17.3% compared to existing works.

     

An efficient neural-network model for real-time fault detection in industrial machine

Neural Computing and Applications - Induction machines have extensive demand in industries as they are used for large-scale production and, therefore, vulnerable to both electrical and mechanical...