Dielectric and thermal response of poly[(vinylidene chloride)‐co‐acrylonitrile]/poly(methyl methacrylate) blend membranes

Poly(methyl methacrylate) was mixed with poly[(vinylidene chloride)‐co‐acrylonitrile] (Saran‐F) and lithium perchlorate in tetrahydrofuran to make polymer blend systems. Solvent‐free membranes with various blend ratios were prepared using a solution casting technique. Impedance analysis was used to study the electrical response of the polymer membranes, which shows that the 50:50 wt% blend ratio polymer membrane has a low bulk resistance and high dielectric constant at room temperature and hence high ionic conductivity. The dielectric behaviour was analysed using dielectric permittivity and electric modulus of the samples. The conductance spectra follow the universal power law variation. Structural analysis confirms the amorphous nature and functional group analysis confirms the miscibility. The decomposition temperature of the membranes was determined using thermogravimetric analysis. © 2014 Society of Chemical Industry     

Protective role of air potato (Dioscorea bulbifera) of yam family in myocardial ischemic reperfusion injury

Hydroalcoholic extract of Dioscorea bulbifera (DB), a yam variety called air potato, was tested for its protective effect on myocardial ischemic/reperfusion (I/R) injury in rats due to apoptosis and necrosis. Myocardial I/R injury was induced by 30 min ischemia followed by 2 h reperfusion by perfusing isolated rat hearts with Krebs Henseilet bicarbonate (KHB) buffer in a Langendorff set up. Pretreatment of DB (150 mg kg(-1) body weight) for 30 days significantly reduced myocardial infarct size and improved the ventricular function (aortic flow and coronary flow, LVDP, LVmax dp/dt). Role of DB on apoptosis was also evaluated by determining caspase 3 as well as by examining pro-apoptotic and anti-apoptotic proteins Bax and Bcl2 by Western blot analysis followed by TUNEL assay. DB also prevented I/R-mediated down regulation of survival protein Akt and HO-1. Our results indicated that Dioscorea bulbifera could ameliorate myocardial ischemia and reperfusion injury by improving ventricular function and inhibition of cardiomyocyte necrosis and apoptosis.     

Influence of surfactants on structural,morphological, optical and antibacterial properties of SnO2 nanoparticles

Tin oxide (SnO₂) nanoparticles were synthesised using various surfactants of different charges (n‐cetyl trimethyl ammonium bromide, sodium dodecyl sulphate and TRITON X‐100) by the co‐precipitation method. The synthesised nanomaterials were characterised using different techniques to study their structural, surface morphological, optical and anti‐bacterial activities. X‐ray diffraction patterns revealed the formation of a tetragonal rutile structure in pure and surfactants‐aided SnO₂ nanoparticles and the results show good agreement with JCPDS data [41‐1445]. The crystallite size of SnO₂ nanoparticles was found to decrease with the addition of surfactants. Scanning electron microscopy images exhibit spherical shape morphology with an average diameter of 30–75 nm for pure and surfactants‐aided SnO₂ nanoparticles. The band gap energy of the prepared materials was estimated from the UV–visible absorption spectra and a considerable increase in band gap energy was observed in surfactants‐aided SnO₂ nanoparticles (3.487, 3.57, 3.50 and 3.3 eV). The antibacterial activities of the synthesised nanoparticles were studied against Escherichia coli and Staphylococcus aureus bacteria.Inspec keywords: visible spectra, precipitation (physical chemistry), ultraviolet spectra, nanofabrication, tin compounds, X‐ray diffraction, crystallites, titanium compounds, particle size, antibacterial activity, surfactants, nanoparticles, energy gap, scanning electron microscopy, surface morphology, semiconductor materials, optical constants, semiconductor growthOther keywords: SnO₂ , co‐precipitation method, anti‐bacterial activities, X‐ray diffraction patterns, tetragonal rutile structure, spherical shape morphology, band gap energy, sodium dodecyl sulphate surfactant, surface morphology, surfactant‐aided SnO₂ nanoparticles, crystallite size, scanning electron microscopy, UV–visible absorption spectra, Escherichia coli, Staphylococcus aureus bacteria, TRITON X‐100 surfactant, n‐cetyl trimethyl ammonium bromide surfactant     

An Efficient DWT and Intuitionistic Fuzzy Based Multimodality Medical Image Fusion

Image fusion aims to integrate complementary information from multiple modalities into a single image with none distortion and loss of data. Image fusion is important in medical imaging, specifically for the purpose of detecting the tumor and identification of diseases. In this article, completely unique discrete wavelet transform (DWT) and intuitionistic fuzzy sets (IFSs) based fusion method (DWT‐IFS) is proposed. For fusion, initially, all source images are fused using DWT with the average, maximum, and entropy fusion rules. Besides, on the fused image IFS is applied. In the IFS process images are converted into intuitionistic fuzzy images (IFIs) by selecting an optimum value for the parameter in membership, non‐membership, and hesitation degree function using entropy. Then, the resulting IFIs are decomposed into the blocks, and the corresponding blocks of the images are fused using the intersection and union operations of IFS. The efficiency of the proposed DWT‐IFS fusion method is recognized by examining it with other existing methods, such as Averaging (AVG), Principal Component Analysis (PCA), Laplacian Pyramid Approach (LPA), Contrast Pyramid Approach (CPA), Discrete Wavelet Transform (DWT), Morphological Pyramid Approach (MPA), Redundancy Discrete Wavelet Transform (RDWT), Contourlet Transform (CONTRA), and Intuitionistic Fuzzy Set (IFS) using subjective and objective performance evaluation measures. The experimental results reveal that the proposed DWT‐IFS fusion method provides higher quality of information in terms of physical properties and contrast as compared to the existing methods.     

Automatic resource allocation in a distributed camera network

In this paper, we present a hierarchical smart resource coordination and reconfiguration framework for distributed systems. We view the coordination problem as one of context aware resource reconfiguration. The fundamental unit in this hierarchy is a Fault Containment Unit (FCU) that provides run-time fault-tolerance by deciding on the best alternative course of action when a failure occurs. FCUs are composed hierarchically and are responsible for dynamically reconfiguring failing FCUs at lower levels. When such a reconfiguration is not possible, FCUs propagate the failure upward for resolution. We evaluate the effectiveness of our framework in a people tracking application using a network of cameras. The task for our multi-camera network is to allocate pairs of cameras that localize a subject optimally given the current run-time context. The system automatically derives policies for switching between camera pairs that enable robust tracking while being attentive to certain performance measures. Our approach is unique in that we model the dynamics in the scene and the camera network configuration steers the policies to provide robust tracking.     

Global optimization for scheduling refinery crude oil operations

In this work we present an outer-approximation algorithm to obtain the global optimum of a nonconvex mixed-integer nonlinear programming (MINLP) model that is used to represent the scheduling of crude oil movement at the front-end of a petroleum refinery. The model relies on a continuous time representation making use of transfer events. The proposed algorithm focuses on effectively solving a mixed-integer linear programming (MILP) relaxation of the nonconvex MINLP to obtain a rigorous lower bound (LB) on the global optimum. Cutting planes derived by spatially decomposing the network are added to the MILP relaxation of the original nonconvex MINLP in order to reduce the solution time for the MILP relaxation. The solution of this relaxation is used as a heuristic to obtain a feasible solution to the MINLP which serves as an upper bound (UB). The lower and upper bounds are made to converge to within a specified tolerance in the proposed outer-approximation algorithm. On applying the proposed technique to test examples, significant savings are realized in the computational effort required to obtain provably global optimal solutions.     

Treatment of wastewater from synthetic textile industry by electrocoagulation–electrooxidation

Treatment of wastewater from a textile industry that produces synthetic polyester cloths was studied employing electrochemical techniques. The sample was initially subjected to electrocoagulation to remove suspended solids. Mild steel and aluminum electrodes were tried as anodes; and aluminum was found to be effective for the removal of suspended solids. Using aluminum as anode, the chemical oxygen demand (COD) concentration of the effluent which was initially at the level of 1316 mg L⁻¹ could be reduced to 429 mg L⁻¹ by electrocoagulation. After electrocoagulation, the effluent was further subjected to electrooxidation using graphite and RuO₂/IrO₂/TaO₂ coated titanium as anodes. During the electrooxidation tests, both COD and chloride ion were simultaneously estimated; and the effect of Cl⁻ ion is discussed. The measurements have revealed the depletion of Cl⁻ ion concentration implying the generation of free chlorine during electrooxidation. The depletion of Cl⁻ ion concentration and the COD removal were observed to be comparatively high in the presence of graphite electrode. The effects of electrode materials and current density on COD removal are discussed. The instantaneous current efficiency (ICE), mass transfer coefficient and energy consumption were estimated.     

A secure authentication scheme based on elliptic curve cryptography for IoT and cloud servers

The Internet of Things (IoT) is now a buzzword for Internet connectivity which extends to embedded devices, sensors and other objects connected to the Internet. Rapid development of this technology has led to the usage of various embedded devices in our daily life. However, for resource sharing and communication among these devices, there is a requirement for connecting these embedded devices to a large pool of resources like a cloud. The promising applications of IoT in Government and commercial sectors are possible by integrating cloud servers with these embedded devices. But such an integration of technologies involves security issues like data privacy and authentication of devices whenever information is exchanged between them. Recently, Kalra and Sood proposed an authentication scheme based on elliptic curve cryptography (ECC) for IoT and cloud servers and claimed that their scheme satisfies all security requirements and is immune to various types of attacks. However, in this paper, we show that Kalra and Sood scheme is susceptible to offline password guessing and insider attacks and it does not achieve device anonymity, session key agreement, and mutual authentication. Keeping in view of the shortcomings of Kalra and Sood’s scheme, we have proposed an authentication scheme based on ECC for IoT and cloud servers. In the proposed scheme in this paper, we have formally analyzed the security properties of the designed scheme by the most widely accepted and used Automated Validation of Internet Security Protocols and Applications tool. Security and performance analysis show that when compared with other related schemes, the proposed scheme is more powerful, efficient, and secure with respect to various known attacks.