Some Transition Metal Salts of 4,6‐Dinitrobenzofuroxan: Synthesis,Characterization and Evaluation of Their Properties

Chromium, Iron and Copper salts of 4,6‐dinitrobenzofuroxan have been prepared by reacting sodium salt of 4,6‐dinitrobenzofuroxan with chromium nitrate nonahydrate, ferric nitrate nonahydrate and cupric nitrate trihydrate, respectively. The compounds have been characterized by elemental analysis, spectral data (IR and NMR) and metal content. Some properties including thermal and explosive behaviour of these compounds have been investigated and reported. Further, these molecules have also been investigated in composite propellants as burn‐rate modifiers. The preliminary data suggest that iron salt of 4,6‐dinitrobenzofuroxan is better than ferric oxide, generally used as a burn‐rate modifier for hydroxy‐terminated polybutadiene (HTPB) based composite propellants.     

Properties of Two Broad Host Range Phages of Yersinia enterocolitica Isolated from Wild Animals

Yersinia (Y.) enterocolitica and Y. pseudotuberculosis are important zoonotic agents which can infect both humans and animals. To combat these pathogens, the application of strictly lytic phages may be a promising tool. Since only few Yersinia phages have been described yet, some of which demonstrated a high specificity for certain serotypes, we isolated two phages from game animals and characterized them in terms of their morphology, host specificity, lytic activity on two bio-/serotypes and genome composition. The T7-related podovirus vB_YenP_Rambo and the myovirus vB_YenM_P281, which is very similar to a previously described phage PY100, showed a broad host range. Together, they lysed all the 62 tested pathogenic Y. enterocolitica strains belonging to the most important bio-/serotypes in Europe. A cocktail containing these two phages strongly reduced cultures of a bio-/serotype B4/O:3 and a B2/O:9 strain, even at very low MOIs (multiplicity of infection) and different temperatures, though, lysis of bio-/serotype B2/O:9 by vB_YenM_P281 and also by the related phage PY100 only occurred at 37 °C. Both phages were additionally able to lyse various Y. pseudotuberculosis strains at 28 °C and 37 °C, but only when the growth medium was supplemented with calcium and magnesium cations.     

Intensification of hydrogen production by B. licheniformis using kitchen waste as substrate

Bacillus licheniformis AP1 isolated from dairy waste cheese whey water possess pyruvate formate lyase (PFL) and formate hydrogen lyase (FHL) enzyme gene which can hydrolyze pyruvate and formate to produce hydrogen under anaerobic conditions. Molecular characterization of this strain was done using 16rRNA gene sequencing. Phylogenetic tree was formed on the basis of neighbor-joining method using MEGA5 which showed that no significant change occurred in 16s rRNA during the course of evolution. Biohydrogen production using this laboratory isolate was performed using pre-treated kitchen waste as substrate at optimized pH 6.5 with yield of 12.29 ± 1.2 mmolH₂/gCOD reduced. Effect of macronutrients and micronutrients were studied by varying concentrations on the hydrogen production. Hydrogen production substantially increased from 14.10 ± 1.4 mmolH₂/gCOD, 17.027 ± 1.7 mmolH₂/gCOD, 17.029 ± 1.7 mmolH₂/gCOD to 17.62 ± 1.8 mmol/gCOD reduced kitchen waste by B. licheniformis at optimized concentrations of –different metals like magnesium (MgCl₂) 0.59 g/L, nitrogen (NH₄Cl) 7 g/L, nickel (NiCl₂) 180 μg/L, and iron (II) (FeSO₄) 67 μg/L respectively. The optimized temperature for this process was found to be 34 ± 2 °C with the maximal hydrogen yield of 17.62 ± 1.8 mmol/g COD reduced kitchen waste. The end fermentation metabolites detected were acetic acid, isobutyl acid, butyric acid, and pyruvic acid in the proportion of 3.75:1:1:1 under the optimized conditions in batch experiment (30 ml MGY media broth). These are the products of pyruvate-formate lyase enzyme complex that indicates the major electron flux towards formate during hydrogen production by B. licheniformis in hydrolyzed kitchen waste.     

Accurate computation of field reject ratio based on fault latency

It is shown that the known methods of field reject ratio prediction are not accurate since they fail to realistically model the process of testing. The authors model the detection of a fault by an input test vector as a random event. However, the detection of a fault may be delayed for various reasons: the fault may be detectable only by application of a sequence of vectors or it may not have been targeted until later. In the statistical model, a fault is characterized by two parameters: a per-vector detection probability and an integer-valued latency. Irrespective of the detection probability, the fault cannot be detected by a vector sequence shorter than its latency. The circuit is characterized by the joint distribution of latency and detection probability over all faults. This distribution, obtained by applying the Bayes' rule to the actual test data, allows computations the field reject ratio. The sensitivity of this approach to variations in the measured parameters is also investigated     

Hydrodynamic permeability of membranes built up by spherical particles covered by porous shells: effect of stress jump condition

This paper concerns the flow of an incompressible, viscous fluid past a porous spherical particle enclosing a solid core, using particle-in-cell method. The Brinkman’s equation in the porous region and the Stokes equation for clear fluid are used. At the fluid–porous interface, the stress jump boundary condition for the tangential stresses along with continuity of normal stress and velocity components are employed. No-slip and impenetrability boundary conditions on the solid spherical core have been used. The hydrodynamic drag force experienced by a porous spherical particle enclosing a solid core and permeability of membrane built up by solid particles with a porous shell are evaluated. It is found that the hydrodynamic drag force and dimensionless hydrodynamic permeability depends not only on the porous shell thickness, particle volume fraction γ and viscosities of porous and fluid medium, but also on the stress jump coefficient. Four known boundary conditions on the hypothetical surface are considered and compared: Happel’s, Kuwabara’s, Kvashnin’s and Cunningham’s (Mehta–Morse’s condition). Some previous results for the hydrodynamic drag force and dimensionless hydrodynamic permeability have been verified.     

Nano‐dimensional self assembly of regioregular poly (3‐hexylthiophene) in toluene: Structural,optical, and morphological properties

This article presents the optimization and systematic analysis of the growth kinetics of fiber formation of the regio‐regular poly (3‐hexylthiophene), rr‐P3HT. In addition to it a comparative study of as‐prepared fiber with fresh, quenched (at ?7°C) and commercial rr‐P3HT formed in toluene solvent. The rr‐P3HT (M_w ≈ 5340; polydispersity ≈ 1.22) is synthesized using a well known Grignard metathesis reaction and characterized by ¹HNMR and FTIR techniques. The films obtained by the ageing of rr‐P3HT solution for 20 days contain nanostructured fiber with 6–10 nm thickness. However, it acquires a nanostructured globular shape when same concentration of solution is sudden quenched at ?7°C. A saturation point for the growth of nano fiber is observed under UV–visible study and it is found that 10 days are sufficient for fiber growth. The concentration dependent free exciton band width of fiber growth is studied by Frank–Condon principle and correlated with AFM morphological studies. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40931.     

Through-Thickness Deformation Gradient in a Part-Pilgered Zirconium Tube: Experimental Measurements and Numerical Validation

Metallurgical and Materials Transactions A - Through-thickness microstructure development and residual stress evolution were explored in a part-pilgered Zircaloy-4 tube. Clear gradients in...