Thread-Parallel Integrated Test Pattern Generator Utilizing Satisfiability Analysis

Efficient utilization of the inherent parallelism of multi-core architectures is a grand challenge in the field of electronic design automation (EDA). One EDA algorithm associated with a high computational cost is automatic test pattern generation (ATPG). We present the ATPG tool TIGUAN based on a thread-parallel SAT solver. Due to a tight integration of the SAT engine into the ATPG algorithm and a carefully chosen mix of various optimization techniques, multi-million-gate industrial circuits are handled without aborts. TIGUAN supports both conventional single-stuck-at faults and sophisticated conditional multiple stuck-at faults which allows to generate patterns for non-standard fault models. We demonstrate how TIGUAN can be combined with conventional structural ATPG to extract full benefit of the intrinsic strengths of both approaches.     

Removal of Endosulfan from Water Using Wood Charcoal—Adsorption and Desorption

Endosulfan, one of the most widely used pesticides in various sectors including agriculture, has been reported posing a threat to the ecology as well as to the environment. Contamination of groundwater and surface water sources with various pesticides is well documented, and this problem is prominent, particularly in rural areas. In the present study, efforts are made to remove endosulfan from water using wood charcoal, a local and low cost adsorbent. It gave removal efficiency of more than 90%. Equilibrium time was found to be around 5?h. Wood charcoal showed an uptake capacity of 0.53?mg/g with initial endosulfan concentration in the range of 0.25–5?mg/L and 1.77?mg/g for the range of 2–50?mg/L. Langmuir isotherm gave a better prediction of adsorption capacity than the Freundlich. The Langmuir isotherm fit also gave a better correlation with the experimental data. In the desorption study carried out, 10% solutions of acetone, methanol, acetic acid, saturated EDTA solution, and distilled water were used as eluents. Ten percent methanol solution was found performing well with an adsorbent regeneration of more than 80% after four cycles of adsorption desorption. Desorption was found to follow a zero order equation in the case of 10% solutions of both acetone and methanol.     

Graphene oxide/poly(<Emphasis Type="Italic">N</Emphasis>-isopropyl acrylamide)/sodium alginate-based dual responsive composite beads for controlled release characteristics of chemotherapeutic agent

In this work, graphene oxide (GO)-incorporated composite beads were developed from poly(N-isopropyl acrylamide)/sodium alginate (PNIPAM/NaAlg) using ionotropic gelation technique. The interaction between GO and PNIPAM/NaAlg with Ca²⁺ ions as a cross-linker was investigated by Fourier transform spectroscopy. X-Ray diffraction pattern showed that the GO was distributed uniformly in the PNIPAM/NaAlg with Ca²⁺ ions while scanning electron micrograph technique revealed that composite beads were formed in spherical shape. The controlled release characteristics of composite beads were studied using 5-fluorouracil (5-FU) as anti-cancer model drug. The encapsulation efficiencies were found to be between 90 and 92% in all formulations. Furthermore, the equilibrium swelling ratio (%) and in vitro release studies of the beads were carried out in two different pH values of 1.2 and 7.4 and at different temperature conditions of 25 and 37 °C. The obtained results showed that the swelling ratio decreased with an increase in GO concentration. In vitro release studies performed in response to both pH and temperature and they proved that the 5-FU drug was released from composite beads over 32 h without burst release. Cytotoxicity results showed pristine composite beads are good cytocompatible. In addition, the cytotoxicity of 5-FU was found to be improved when incorporated with composite beads than pure 5-FU. It is therefore concluded that the developed composite beads have dual response and can be used as controlling released carriers in cancer drug delivery applications.     

Simulating the Role of TCO Materials,their Surface Texturing and Band Gap of Amorphous Silicon Layers on the Efficiency of Amorphous Silicon Thin Film Solar Cells

In this work, through modeling we propose how the choice of the TCO material, its texturing and optimization of band gap of a-Si:H layers help to increase the efficiency of a-Si:H solar cells. While selecting plane and textured indium tin oxide (ITO) and zinc oxide (ZnO) as TCOs, the solar cell parameters and performance are examined as a function of band gap of different a-Si:H layers. The optimum band gap values of 2.1 eV, 1.9 eV and 1.85 eV are obtained for p, i and n-layers of a-Si:H with maximum efficiencies of ~ 15.5 % and 17.7 % using plane ITO and ZnO contacts respectively. Interestingly, the conversion efficiency is further increased to ~ 16.3 % and 18.6 % when textured ITO and textured ZnO are used as TCOs. Moreover the higher efficiencies with ZnO-based contact than ITO-based contact can be explained due to slightly higher drift velocity of holes nearer to the junction and little improved optical properties which may also attributes to the enhanced trapping of the light. These results are very encouraging and may help in developing a-Si:H based solar cell technology for thin films.     

Enrichment of piezoelectric properties in Nb5+doped (0.94) (Na0.5Bi0.5)TiO3–(0.06) BaTiO3 ceramics across morphotropic phase boundary region

Lead-free piezoelectric compounds (0.94)(Na_0.5Bi_0.5)TiO₃–(0.06) BaTiO₃ [NBBT (94/06)]?+?x wt.% Nb⁵⁺ (x?=?0%, 1%, 1.5%, 2%, and 2.5%) were synthesized by the solid-state reaction route and these powders were pelletized and sintered for dielectric and piezoelectric characterization. The phase coexistence Monoclinic (Cc)?+?Rhombohedral (R3c) was affirmed using X-ray Powder diffraction analysis. The structural properties like cell parameters and space group of the synthesized ceramics were investigated by the Rietveld refinement analysis. The surface morphology and grain size of the fractured ceramics were explored using SEM imaging technique. The dielectric properties for all the ratios of NBBT (94/06) ceramics were examined using LCR meter. The piezoelectric coefficients such as d₃₃ and g₃₃ of Nb-doped NBBT (94/06) ceramics were investigated. The saturation polarization (P_s) and remanent polarization (P_r) were exhibited from the P–E hysteresis loop analysis at room temperature. The appropriate addition of Nb⁵⁺ (x?=?1.5%) in NBBT (94/06) material demonstrates eminent dielectric constant and piezoelectric coefficient d₃₃ than other wt.% of Nb. The replacement of Ti⁴⁺ with higher radius cations Nb⁵⁺ in B-site of ABO₃ composes tilting of polar BO₆ octahedra resulting in rhombohedra distortion (RD) (90° ? α), in addition, the polarizability of ions and various valance states of B-site cations could be responsible for RD (90° ? α) ensuing relatively high dielectric constant and piezoelectricity.

     

Preparation and characterization of poly(ethylene glycol) stabilized nano silver particles by a mechanochemical assisted ball mill process

Nano silver particles with an average mean crystallite size of between 10 and 12 nm were synthesized from different molecular weights of poly(ethylene glycol) as a stabilizing agents, through solid state oxidation of silver nitrate using a higher energy planetary ball mill. Ultraviolet‐Visible spectra were used to confirm the synthesis of nano silver particles. The surface plasmon resonance bands were observed around 410 nm. Fourier transformed infrared spectrum, X‐ray diffraction, and transmission electronic microscopy techniques were used to characterize the nano silver particles synthesized. Thermal stability was determined using thermogravimetic analysis and the elemental composition of the sample was determined by energy dispersive X‐ray analysis. The nano silver particles synthesized, exhibited very good antibacterial activity against Gram‐positive bacteria (Bacillus) and Gram‐negative bacteria (Pseudomonas aeruginosa). Based on the obtained results, it was additionally explored that the size and the stabilization of the nano silver particles synthesized, strongly depend on the molecular weight of poly(ethylene glycol). © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43027.     

Pore size control and electrochemical capacitor behavior of chemically activated polyacrylonitrile – Carbon nanotube composite films

Activated polyacrylonitrile (PAN)/carbon nanotube (CNT) composite film based electrodes have been prepared by chemical activation with potassium hydroxide for electrochemical capacitors. This paper analyses the following aspects of specific capacitance, pore size distribution and surface area: influence of activation temperature, molarity of activating agent, composition of PAN/carbon nanotube precursor films and electrolytes. A maximum value of specific capacitance of ∼302 Fg⁻¹ was achieved for the samples activated at 800 °C. Energy density for PAN/CNT 80/20 sample when tested with ionic liquid/organic electrolyte system was as high as ∼22 W h kg⁻¹. Pore size control predominantly below 5 nm was observed in these activated PAN samples. Data analysis showed that micropores make a significant contribution to the capacitance performance of these materials in both 6 M KOH as well as in BMIMBF₄/acetonitrile electrolytes.     

Characterization of Inoculated Low Carbon Equivalent Iron at Lower Austempering Temperature

The response of inoculated low carbon equivalent iron to austempering heat treatment has remained as an unchartered area of investigation. The carbon equivalent of inoculated low carbon equivalent iron is much lesser than that of ductile iron, while modulus of elasticity is higher than it. This paper examines and compares the austempering transformations and microstructural changes during austempering of ductile iron and inoculated low carbon equivalent iron with respect to austempering parameters. The optical metallography and X-ray diffraction techniques are used to study the changes in the austempered structure. The alterations in austempered microstructure and structural parameters like, austenite volume fraction (X) and its carbon content (C) at an austempering temperature of 250?°C are studied in the present investigation. It is observed that, austempering heat treatment produces fine ausferritic microstructure, similar to that present in austempered ductile iron at this temperature. However, some significant differences between the austempered microstructure of two alloys are noted.     

Advances in nonlinear vibration analysis of structures. Part-I. Beams

The development of nonlinear vibration formulations for beams in the literature can be seen to have gone through distinct phases — earlier continuum solutions, development of appropriate forms, extra-variational simplifications, debate and discussions, variationally correct formulations and finally applications. A review of work in each of these phases is very necessary in order to have a complete understanding of the process of evolution of this field. This paper attempts to achieve precisely this objective.