A new computational approach for edge-preserving image decomposition

Multimedia Tools and Applications - Decomposition of an image into its cartoon part and texture part has been an interesting area of research. It is an important pre-processing step in many...     

Load-sharing system model and its application to the real data set

This study deals with the classical and Bayesian estimation of the parameters of a k-components load-sharing parallel system model in which each component's lifetime follows Lindley distribution. Initially, the failure rate of each of the k components in the system is h(t,θ₁) until the first component failure. However, upon the first failure within the system, the failure rates of the remaining (k − 1) surviving components change to h(t,θ₂) and remain the same until next failure. After second failure, the failure rates of (k − 2) surviving components change to h(t,θ₃) and finally when the (k − 1)th component fails, the failure rate of the last surviving component becomes h(t,θ_k). In classical set up, the maximum likelihood estimates of the load share parameters, system reliability and hazard rate functions along with their standard errors are computed. 100 × (1 − γ)% confidence intervals and two bootstrap confidence intervals for the parameters have also been constructed. Further, by assuming Jeffrey's invariant and gamma priors of the unknown parameters, Bayes estimates along with their posterior standard errors and highest posterior density credible intervals of the parameters are obtained. Markov Chain Monte Carlo technique such as Metropolis–Hastings algorithm has been utilized to generate draws from the posterior densities of the parameters.     

Analysis and performance of novel and highly efficient electronic ballast operating at unity-power-factor

This paper presents the electronic ballast, in which the coupling inductors are used to inject the current to the dc-bus capacitors, to boost the dc-bus voltage and to filter out the ripples from input line current. The current injection coupling inductor injects its stored energy to the dc-bus capacitors in every switching half cycle. Whereas, the boost coupling inductor keeps the dc-bus voltage always above the peak of ac input voltage. Therefore, the proposed ballast maintains unity-power-factor and high efficiency with ripple-free input current over wide range of input line voltage in case of worst regulation. A symmetrical half-bridge inverter is used to drive the fluorescent lamps. The experimental results of the laboratory prototype ballast for 2 × 36 W fluorescent lamps operating at 50 kHz are presented.     

Bayes estimation of the mixture of hazard-rate model

Engineering systems are subject to continuous stresses and shocks which may (or may not) cause a change in the failure pattern of the system with unknown probability q( =1 − p), 0 < p < 1. Conceptualising a mixture of hazard-rate or failure-rate patterns representing a realistic situation, the failure time distribution is given in the corresponding case. Classical and Bayesian estimation of the parameters and reliability characteristics of this failure time distribution is the subject matter of the present study.     

Study on viscosity of conventional and polymer modified asphalt binders in steady and dynamic shear domain

This study focuses on evaluating the flow behavior of conventional and polymer modified asphalt binders in steady- and dynamic-shear domain, for a temperature range of 20–70 °C, using a Dynamic Shear Rheometer (DSR). Steady-shear viscosity and frequency sweep tests were carried out on two conventional (VG 10 and VG 30) and two polymer (SBS and EVA) modified asphalt binders. Applicability of the Cox–Merz principle was evaluated and complex viscosity master curves were analyzed at five different reference temperatures. Cross model was used to simulate the complex viscosity master curves at different temperatures.It was found that asphalt binders exhibited shear-thinning behavior at all the test temperatures. The critical shear rate increased with increase in temperature and was found to be lowest for plastomeric modified asphalt binder. The Cox–Merz principle was found to be valid in the zero-shear viscosity (ZSV) domain and deviated at higher frequency/shear rate for all the binders. Results from the study indicated that the ratio of ZSV can be successfully used as shift factors for construction of master curves at different reference temperatures. Cross model was found to be suitable in simulating the complex viscosity master curves at all the test temperatures. Analysis of model parameters indicated that a strong relationship exists between ZSV and the critical shear rate. ZSV and critical shear rate varied exponentially with temperature. This relationship was used to propose a simple equation for assessing the shift factors for construction of master curves.     

Influence of antibiotic adsorption on biocidal activities of silver nanoparticles

Excessive use of antibiotics has posed two major challenges in public healthcare. One of them is associated with the development of multi‐drug resistance while the other one is linked to side effects. In the present investigation, the authors report an innovative approach to tackle the challenges of multi‐drug resistance and acute toxicity of antibiotics by using antibiotics adsorbed metal nanoparticles. Monodisperse silver nanoparticles (SNPs) have been synthesised by two‐step process. In the first step, SNPs were prepared by chemical reduction of AgNO₃ with oleylamine and in the second step, oleylamine capped SNPs were phase‐transferred into an aqueous medium by ligand exchange. Antibiotics – tetracycline and kanamycin were further adsorbed on the surface of SNPs. Antibacterial activities of SNPs and antibiotic adsorbed SNPs have been investigated on gram‐positive (Staphylococcus aureus, Bacillus megaterium, Bacillus subtilis), and gram‐negative (Proteus vulgaris, Shigella sonnei, Pseudomonas fluorescens) bacterial strains. Synergistic effect of SNPs on antibacterial activities of tetracycline and kanamycin has been observed. Biocidal activity of tetracycline is improved by 0–346% when adsorbed on SNPs; while for kanamycin, the improvement is 110–289%. This synergistic effect of SNPs on biocidal activities of antibiotics may be helpful in reducing their effective dosages.Inspec keywords: silver, silver compounds, nanomedicine, nanoparticles, drug delivery systems, drugs, antibacterial activity, microorganisms, nanofabrication, materials preparation, reduction (chemical), adsorption, surface chemistry, surface treatmentOther keywords: public healthcare, multi‐drug resistance, side effect, acute antibiotic toxicity, antibiotic adsorbed metal nanoparticle, monodisperse silver nanoparticle, two‐step SNP synthesis, SNP preparation, AgNO₃ chemical reduction, oleylamine capped SNP phase‐transfer, aqueous medium, ligand exchange, tetracycline, kanamycin, antibacterial activity, antibiotic adsorbed SNP, gram‐positive bacterial strain, Staphylococcus aureus, Bacillus megaterium, Bacillus subtilis, gram‐negative bacterial strain, Proteus vulgaris, Shigella sonnei, Pseudomonas fluorescens, SNP synergistic effect, effective dosage reduction, Ag, AgNO₃      

Systematic Efficiency Improvement for Cu2ZnSn(S,Se)4 Solar Cells By Double Cation Incorporation with Cd and Ge

The performance of kesterite Cu₂ZnSn(S,Se)₄ (CZTSSe) solar cell is known to be severely limited by the nonradiative recombination near the heterojunction interface and within the bulk of the CZTSSe absorber resulting from abundant recombination centers and limited carrier collection efficiency. Herein, nonradiative recombination is simultaneously reduced by incorporating small amounts of Ge and Cd into the CZTSSe absorber. Incorporation of Ge effectively increases the p-type doping, thus successfully improving the bulk conductance and reducing the recombination in the CZTSSe bulk via enhanced quasi-Fermi level splitting, while the incorporation of Cd greatly reduces defects near the junction region, enabling larger depletion region width and better carrier collection efficiency. The combined effects of Cd and Ge incorporation give rise to systematic improvement in open-circuit voltage (V_OC), short-circuit current density (J_SC), and fill factor (FF), enabling a high conversion efficiency of 11.6%. This study highlights the multiple cation incorporation strategy for systematically manipulating the opto-electronic properties of kesterite materials, which may also be applicable to other semiconductors.     

Ultra-Fast Current Mode Sense Amplifier for Small $$I_{\mathrm{CELL}}$$ SRAM in FinFET with Improved Offset Tolerance

In this paper, a novel, high-performance and robust sense amplifier (SA) design is presented for small \(I_\mathrm{CELLl}\) SRAM, using fin-shaped field effect transistors (FinFET) in 22-nm technology. The technique offers data-line-isolated current sensing approach. Compared with the conventional CSA (CCSA) and hybrid SA (HSA), the proposed current feed-SA (CF-SA) demonstrates 2.15\(\times \) and 3.02\(\times \) higher differential current, respectively, for \({V}_{\mathrm{DD}}\) of 0.6 V. Our results indicate that even at the worst corner, CF-SA can provide 2.23\(\times \) and 1.7\(\times \) higher data-line differential voltage compared with CCSA and HSA, respectively. Further, 66.89 and 31.47 % reductions in the cell access time are achieved compared to the CCSA and HSA, respectively, under similar \(I_\mathrm{CELLl}\) and bit-line and data-line capacitance. Statistical simulations have proved that the CF-SA provides high read yield with 32.39 and 22.24 % less \(\upsigma _{\mathrm{Delay}}\). It also offers a much better read effectiveness and robustness against the data-line capacitance as well as \({V}_{\mathrm{DD}}\) variation. Furthermore, the CF-SA is able to tolerate a large offset of the input devices, up to 80 mV at \({V}_{\mathrm{DD}}=0.6\hbox {V}\).     

Mitigating the Blunt Trauma of Soft Armour Panels using Polycarbonate Sheets: A Cost-effective Solution

Applied Composite Materials - Reduction of back face signature (BFS) or blunt trauma of soft armour panel (SAP) is one of the major aspects of armour design. This research explores the use of stiff...     

Cellular Interactions and Modulated Osteoblasts Functions Mediated by Protein Adsorption

The rapid adsorption of proteins is one of the first few events that occur when a biomedical device is implanted and strongly affects attachment and proliferation of cells on the material surface. We describe here for the first time the favorable modulation of osteoblasts functions and cell–substrate interactions induced by protein adsorption (bovine serum albumin) on silicone elastomers. It was intriguing that the cell–substrate interactions on protein‐adsorbed silicone elastomer were significantly different from those observed in stand alone silicone. The origin and differences in cell–substrate interactions in terms of cell attachment, viability, and proliferation and assessment of proteins actin, vinculin, and fibronectin are addressed. Cell attachment and proliferation of cells were significantly enhanced on protein‐adsorbed surface in comparison to the bare surface. Similarly, the expression level of fibronectin, actin, and vinculin was appreciably greater on the protein‐adsorbed surface. The study underscores that protein adsorption on artificial biomedical devices can be envisaged as one of the methods to enhance the bioactivity on the surface and regulate biological functions.