Multiferroic Consequence of Porous (BiFeO_3)_x–(BiCrO_3)_(1-x) Composite Thin Films by Novel Sol–Gel Method

In this work, we have presented a spin-coating method to produce thin films started with pure BiCrO_3(BCO) and ended up with BiFeO_3(BFO) by increasing x values in the(BiFeO_3)_x–(BiCrO_3)_(1-x)composites. All the produced thin films have been crystallized at the annealing temperatures of 400 °C for 0.5 h. The XRD and EDAX spectrums give insight that the two crystal phases related to BCO and BFO stayed together within the thin film matrices. SEM analysis showed that the prepared composite had macroporous morphology with interconnected pores and its width(size) decreased with increasing x values. The strong correlations are observed among the microstructure, dielectric, ferroelectric, ferromagnetic properties and Fe concentration. Among all composites, the composition of 0.75 shows an attractive magnetization, polarization, switching and improved dielectric behaviors at room temperature. Significant increase in the multiferroic characteristics of 0.75 composition is due to arise of lower leakage current by causing reduction in oxygen vacancy density, and enhancement of super-exchange magnetic interaction between Fe~(3+) and Cr~(3+) at BFO/BCO interface layers. Our result shows that the thin layer on Pt(111)/Ti/SiO_2/Si substrate possesses simultaneously improved ferroelectric and ferromagnetic properties which make an inaccessible potential application for nonvolatile ferroelectric memories.     

Synthesis and electrochemical characterizations of nano-scaled Zn doped LiMn2O4 cathode materials for rechargeable lithium batteries

The LiZn_xMn_2−xO₄ (x = 0.00-0.15) cathode materials for rechargeable lithium-ion batteries were synthesized by simple sol-gel technique using aqueous solutions of metal nitrates and succinic acid as the chelating agent. The gel precursors of metal succinates were dried in vacuum oven for 10 h at 120 °C. After drying, the gel precursors were ground and heated at 900 °C. The structural characterization was carried out by X-ray powder diffraction and X-ray photoelectron spectroscopy to identify the valance state of Mn in the synthesized materials. The sample exhibited a well-defined spinel structure and the lattice parameter was linearly increased with increasing the Zn contents in LiZn_xMn_2−xO₄. Surface morphology and particle size of the synthesized materials were determined by scanning electron microscopy and transmission electron microscopy, respectively. Electrochemical properties were characterized for the assembled Li/LiZn_xMn_2−xO₄ coin type cells using galvanostatic charge/discharge studies at 0.5 C rate and cyclic voltammetry technique in the potential range between 2.75 and 4.5 V at a scan rate of 0.1 mV s⁻¹. Among them Zn doped spinel LiZn_0.10Mn_1.90O₄ has improved the structural stability, high reversible capacity and excellent electrochemical performance of rechargeable lithium batteries.     

Effect of strain rate on the mode of fracture in elastoidin

The mechanical properties and fracture behaviour of dry and native elastoidin are studied as a function of strain rate, and the plastic set behaviour of the dry elastoidin is found to be sensitive to strain rate. The results are correlated with the scanning electron microscopy of the fractured ends of dry and native elastoidin. Broken ends of dry elastoidin, fractured at a strain rate of 10.0 min^–1, appear blunt and under the same conditions the native specimen's ends appear sharp.     

Mechanical properties of grafted casein films

Casein was grafted with mixtures of acrylonitrile (AN) and n-butyl methacrylate (n-BMA). The mole ratios of AN: n-BMA were 0.9:0.1 and 0.8:0.2. The mechanical properties of the grafted casein films were studied under uniaxial and biaxial stress conditions. A reduction in longitudinal stress and elongation at break was observed with the simultaneous application of lateral stress. Scanning electron micrographs of the stretched films (uniaxial and biaxial stress) are also presented.     

Genetic spider monkey‐based routing protocol to increase the lifetime of the network and energy management in WSN

Wireless sensor networks (WSNs) include large distributed nodes in the sensing field. However, the sensor nodes may die due to energy deficiency as they are situated in a hostile environment. Therefore, an energy‐efficient WSN routing protocol is necessary in order to better accommodate the various environmental conditions. In this paper, we have proposed a new Energy‐Efficient Genetic Spider Monkey‐based Routing Protocol (EGSMRP) to improve the stability and lifetime of sensor nodes. The operation of EGSMRP is classified into two stages: (i) setup phase and (ii) steady‐state phase. In the setup phase, GSMO‐based cluster head selection procedure is done. In this phase, the base station utilizes the GSMO algorithm as a device to generate energy‐efficient clusters. Followed with this, the steady‐state phase solves the load balancing issue by utilizing the intracluster data broadcast and dual‐hop intercluster broadcasting algorithm. Thereby, the proposed EGSMRP protocol has shown the energy‐based opportunistic broadcasting with reduced control overhead. Simulation is performed in various conditions to evaluate the effectiveness of the proposed EGSMRP protocol using different metrics such as throughput, control overhead, energy consumption, end‐to‐end delay, and network lifetime. From the simulation results, it was evident that EGSMRP has achieved a higher performance compared to other traditional approaches such as EBAR, MCTRP, IEEMARP, HMCEER, and EFTETRP.     

On the use of secret sharing as a secure multi-use pad

Secret sharing (SS) is a cryptographic method proposed independently by Adi Shamir and George Blakley in 1979 to encode the keys of public-key cryptography by splitting them into maximally entropic shares that are distributed to participants, only revealing the secret when combined. Each new sharing instance, even of the same key, produces a different set of shares to distribute anew. This paper investigates SS as an independent cipher to secure confidential messages between a limited set of trusted participants by eliminating the need to redistribute shares. A participant’s master share is permanently fixed and unlimited temporary shares are created and combined with it to reveal new messages. Security is argued against specific and general attacks.     

Fracture behaviour of cross-linked collagen fibres

Mechanical properties such as stress - strain, fracture behaviour and thermal behaviour were studied for cross-linked collagen fibres. The shrinkage temperature of cross-linked fibres shows increase in temperature when compared to the control. The results on measurements of breaking strength and strain show significant change when compared with that of the control. The morphological features of the fractured ends of cross-linked fibres were indicative of certain specific patterns. A critical observation of these patterns indicate the role played by the nature of cross-linking agents on the mechanism of failure of these fibres.     

Microbiological quality of sous-vide cook chill fish cakes during chilled storage (3 °C)

Fish cakes prepared from emperorbream ( Lethrinus lethrinus ) were vacuum packed (VP), conventionally cook-chilled (CCC) and sous-vide cook-chilled (SVCC) and examined for their microbiological quality and safety during chilled storage (3 °C) for a period of 3, 5 and 16 weeks, respectively, in comparison with conventional pack(CP). The shelf life of CP, VP, CCC and SVCC packs of fish cakes were 2, 2, 4 and 16 weeks, respectively, based on the acceptable break point of the overall sensory scores. The total bacterial counts were 5 log cfu g⁻¹, in CP, VP and CCC packs; and 3 log cfug⁻¹ in SVCC pack on sixteenth week. Total lactic acid bacteria were 2 log cfu g⁻¹ on 2 and 3 weeks in CP and VP, respectively. Staphylococci were detected in all packs on sixteenth week at 2 log cfu g⁻¹. Total bacilli were detected in CP and VP at 3 log cfu g⁻¹ level after 2 weeks. Aeromonads were detected after 1, 2 and 4 weeks in CP, VP and CCC packs at 3 log cfu g⁻¹. Total anaerobic sulphite-reducing clostridia were detected only in CP and CCC packs at 3 MPN counts g⁻¹ level on the final day.