Heat conduction and thermal stabilization in YBCO tape

Yttrium barium copper oxide (YBCO) coated conductors are widely used in the conduction-cooled superconducting magnets with rapid development in refrigeration technologies at present. ‘Quench’ is a state that refers to the irreversible and uncontrolled superconductor to resistive transitions in the superconductor. The propagation of ‘quench’ or ‘normal zone’ has different characteristics in these high temperature superconductors (HTS) compared to low temperature superconductors. The superconductor to normal index, known as ‘n’ is much flatter in HTS. The hot spot emerging in local region due to quench and non-uniform critical current may cause permanent damage to whole HTS tape and hence the magnet winding pack. Thus it is necessary to determine the temperature profile along the length of HTS tape under a given energy (joule heating) such that propagation of the hot spot developed locally can be prevented early. In this study, a one dimensional, time dependent heat diffusion equation with appropriate boundary conditions are used to describe the consequences of the normal zone propagation resulting in the temperature diffusion in a HTS tape. The results demonstrate the necessity of adequate cooling of the edges of the flat HTS tapes to prevent irreversible normal zone transitions.     

Synthesis of copper telluride nanowires using template-based electrodeposition method as chemical sensor

Copper telluride (CuTe) nanowires were synthesized electrochemically from aqueous acidic solution of copper (II) sulphate (CuSO₄·5H₂O) and tellurium oxide (TeO₂) on a copper substrate by template-assisted electrodeposition method. The electrodeposition was conducted at 30 °C and the length of nanowires was controlled by adjusting deposition time. Structural characteristics were examined using X-ray diffraction and scanning electron microscope which confirm the formation of CuTe nanowires. Investigation for chemical sensing was carried out using air and chloroform, acetone, ethanol, glycerol, distilled water as liquids having dielectric constants 1, 4·81, 8·93, 21, 24· 55, 42·5 and 80·1, respectively. The results unequivocally prove that copper telluride nanowires can be fabricated as chemical sensors with enhanced sensitivity and reliability.     

Aqueous solution of basic fuchsin as food irradiation dosimeter

Dosimetric characterization of aqueous solution of basic fuchsin was studied spectrophotometrically for possible application in the low-dose food irradiation dosimetry. Absorption spectra of unirradiated and irradiated solu- tions were determined and the decrease in absorbance with the dose was noted down. Radiation-induced bleaching of the dye was measured at wavelengths of maximum absorption λmax (540nm) as well as 510nm and 460 nm. At all these wavelengths, the decrease in absorbance of the dosimeter was linear with respect to the absorbed dose from 50 Gy to 600 Gy. The stability of dosimetric solution during post-irradiation storage in the dark at room temperature showed that after initial bleaching during first ten to twenty days, the response was almost stable for about 34 days. The study on the effect of different light and temperature conditions also showed that the response gradually decreased during the storage period of 34 days, which shows that basic fuchsin dye is photosensitive as well as thermally sensitive.     

Investigation of 50 Hz Pulsed DC Nitrogen Plasma with Active Screen Cage by Trace Rare Gas Optical Emission Spectroscopy

Optical emission spectroscopy is used to investigate the nitrogen-hydrogen with trace rare gas (4% Ar) plasma generated by 50 Hz pulsed DC discharges. The filling pressure varies from 1 mbar to 5 mbar and the current density ranges from 1 mA·cm ⁻² to 4 mA·cm ⁻² . The hydrogen concentration in the mixture plasma varies from 0% to 80%, with the objective of identifying the optimum pressure, current density and hydrogen concentration for active species ([N] and [N ₂ ]) generation. It is observed that in an N ₂ -H ₂ gas mixture, the concentration of N atom density decreases with filling pressure and increases with current density, with other parameters of the discharge kept unchanged. The maximum concentrations of active species were found for 40% H ₂ in the mixture at 3 mbar pressure and current density of 4 mA·cm ⁻²     

Effect of cold compression on precipitation and conductivityof an Al–Li–Cu alloy

Transmission electron microscopy has been used to investigate the effect of increasing the degree of deformation applied by cold compression on the ageing kinetics and electrical conductivity response of an Al–Li–Cu alloy containing Mg and Ag. When cold compressed greater than 3%, the increased dislocation density accelerates the widespread precipitation of the T₁ phase resulting in an enhanced age hardening response. The lengthening rate of T₁ precipitates is also reduced in this cold compressed condition owing to the reduced local solute supersaturation, a result of the widespread precipitation of T₁ plates. Cold compression by less than 3% does not increase the age hardening response, and the precipitation of GP zones/θ″ appears to be suppressed. Precipitation of the T₁ phase is also not significantly enhanced compared with that of the more than 3% cold compressed conditions. The anomalous decrease in electrical conductivity is associated with the nucleation and growth of the T₁ phase. Strain fields around T₁ precipitates combined with the increased volume fraction of T₁ are thought to be the cause of the anomalous conductivity behaviour.     

Effect of Self-Assemblies on the Dynamics of the Briggs–Rauscher Reaction

The study involves the dynamic evolution of the Briggs–Rauscher (BR) reaction in the presence of various surfactants—SDS (sodium dodecyl sulphate) as anionic, CTAB (cetyl trimethylammonium bromide) as cationic and TritonX‐100 [4‐(1,1,3,3‐(tetramethylbutyl) phenyl polyethylene glycol] as a neutral one in single as well as mixed mode conditions (SDS + TX‐100 and CTAB + TX‐100). The reaction has been monitored potentiometrically at 30 °C under CSTR conditions. These surfactants affect the reaction dynamics to an extent which depends on the nature and concentration of the surfactant and the formation of their self‐assemblies. The experimental findings indicate that the oscillatory behavior of the BR reaction in the presence of surfactants is due to the efficacy of organized surfactant assemblies to selectively distribute the key species involved in the reaction, and their interaction with the counter ions in cases of ionic micelles. The study reveals that the evolution of oscillatory behavior is a characteristic feature of the surfactant.     

Extraction and quantification of phenolic compounds from <Emphasis Type="Italic">Prunus armeniaca</Emphasis> seed and their role in biotransformation of xenobiotic compounds

The current research project has been devoted to isolating new low cost and eco-friendly phenolic compounds from fruit seeds, peels and vegetables to reduce the atmospheric pollution. Natural phenolic compounds were extracted from different fruit seeds and agriculture waste: P. armeniaca, P. persica, P. domestica and Triticum aesativum. The total phenolic content was quantified, and the maximum value (1 mL extract having 1,933 μg) was found in P. armeniaca seed extract. Phytochemical screening showed that P. armeniaca seeds contain higher amount of alkaloid, tannins, saponins and flavonoid. P. armeniaca seeds enhanced the biotransformation of reactive yellow dye up to 69.89% with maximum laccase (322.45 IU/mL) production. Biodegradation of reactive yellow was only 23.34% without natural redox mediator at sixth day of incubation. Use of P. armeniaca seed stimulators resulted in maximum laccase activity (894.4 IU/mL) with 99.5% rate of removal. UV-Vis, HPLC & FTIR analysis confirmed the transformation of parent dye into various new products. Phytotoxicity study indicated 0% germination index of Avena sativa seeds with reactive yellow, whereas 83% germination index having 100% seed germination while 83% root elongation with treated sample. Thus, the study revealed that the natural phenolic compounds could serve as high potential redox mediators for enhanced laccase-mediated decolorization of reactive yellow dye.     

Extrusion of Pinto Bean High Protein Fraction Pretreated with Papain and Cellulase Enzymes

High protein fraction of pinto bean was pretreated with papain and cellulase enzymes and extruded at a temperature of 120°C. The effect of enzyme type and concentration, moisture and duration of incubation on expansion, texture, color, water absorption and solubility, pH, sugars, nitrogen solubility index and in vitro protein digestibility of the extrudate were investigated. Enzymatic modification had differential effects on nitrogen and carbohydrate components and on some physical and functional preperties of extrudates, depending on type of enzyme and incubation conditions. Results indicated the possibility of controlling protein and fiber hydrolysis at low moisture to obtain a desirable degree of modification to improve extruded products. This method may be used in food applications to obtain new snack type products from beans or their fractions.     

Gut microbiome modulation: Ancillary effects of inorganic nanoparticles on gut microflora

The association of gut microflora and human health is being increasingly recognized, and the impact of gut microflora on the host is well characterized, including the body’s energy metabolism and immune system maintenance. Several human diseases, including metabolic, autoimmune, obesity, hypothyroidism, and intestinal disorders, are closely associated with gut dysbiosis. Inorganic nanoparticles (NPs) are extensively utilized in numerous fields due to their distinctive, attractive physicochemical properties. Estimation of the potential impacts of NPs, with a high number of microorganisms inside the human body (microbiota) and its genomes (microbiome), represents one of the most important aspects of nano-toxicology. This review article aims to provide information on the association of gut microflora alterations to diseases and describe the impacts of various inorganic NPs, including silver, zinc, selenium, titania, silicon, and copper, on gut microflora. Research on the effect of inorganic NPs on gut microflora of animal models and the poultry industry is reviewed. The response of pathogenic Enterobacter species to inorganic NPs has been expounded in detail. This review also highlights the need to focus on the ancillary effects of various inorganic NPs on gut microflora to expedite the suitable advancement of these particles for future use. Finally, the key opportunistic areas for the application of nanotechnology are underlined to manipulate the microbiome of gut dysbiosis, provide an overview, and address potential challenges and our perspective on this evolving field.