The use of nanophase powders for high Jc superconductor tape production

Advances in processing of superconductors has demonstrated that ceramic powders with exact composition, super-homogeneity, and extremely fine particle size can be prepared by chemical processing to achieve high density and uniform microstructure. The chemical processing routes have great advantage in preparing powder with high reactivity thus promoting solid state reactions required to produce ‘purer’ superconducting phase. We have studied extensively the coprecipitation technique for the preparation of superconducting ceramic powders. Chemical solution methods have been used in order to model several superconducting systems and to predict optimum conditions for obtaining exact composition. Several improvements on the control of precipitation reaction have been implemented in order to obtain powders of few nanometers in size. This has been done by carrying out the reaction in the bulk of a solution or in microemlusion systems. The corecipitated precursor powder has been used for production of 20− 30 meter long Ag-clad tapes. These tapes require considerably reduced processing times. By controlled heat treatment conditions, these tapes have been processed to carry transport critical current density, J_c <4 × 10⁴ A/cm² at 77K in zero applied field.     

Recombinant Baculovirus: A Flexible Drug Screening Platform for Chikungunya Virus

Chikungunya virus (CHIKV) is a mosquito-transmitted infectious agent that causes an endemic or epidemic outbreak(s) of Chikungunya fever that is reported in almost all countries. This virus is an intense global threat, due to its high rate of contagion and the lack of effective remedies. In this study, we developed two baculovirus expression vector system (BEVS)-based approaches for the screening of anti-CHIKV drugs in Spodoptera frugiperda insect (Sf21) cells and U-2OS cells. First, structural protein of CHIKV was co-expressed through BEVS and thereby induced cell fusion in Sf21 cells. We used an internal ribosome entry site (IRES) to co-express the green fluorescent protein (EGFP) for identifying these fusion events. The EGFP-positive Sf21 cells fused with each other and with uninfected cells to form syncytia. We identified that ursolic acid has potential anti-CHIKV activity in vitro, by using this approach. Second, BacMam virus-based gene delivery has been successfully applied for the transient expression of non-structural proteins with a subgenomic promoter-EGFP (SP-EGFP) cassette in U-2OS cells to act as an in vitro CHIKV replicon system. Our BacMam-based screening system has identified that the potential effects of baicalin and baicalein phytocompounds can inhibit the replicon activity of CHIKV in U-2OS cells. In conclusion, our results suggested that BEVS can be a potential tool for screening drugs against CHIKV.     

Evaluation of antioxidant level and protein oxidation of rainbow trout (Oncorhynchus mykiss) fillets during rigor and post-rigor

In this study, the relationship between stunning techniques and protein oxidation which are accepted as the main cause of food spoilage was investigated. For this purpose, the antioxidant status, in vivo myofibrillary protein (MP) oxidation and sensitivity, and postmortem oxidation (inducted with hydroxyl radical system) of rainbow trout (Oncorhynchus mykiss) fillets killed by hitting to head (T1), neck crushing (T2), and convulsion (T3) methods, were investigated. Statistically significant differences (p < .05) were found among all parameters examined and it was observed that the most stressing technique was the convulsion method. It was determined that in protein profiles myosin were influenced too much from stunning technique and in actin observed oxidation-induced reductions. Reductions in S-S and S-H were also found to be increased in carbonyl concentrations, but the most effective values in both processes were determined by the convulsive technique. Our results show that short-term stunning techniques (hitting to head, neck crushing) give better meat quality results in terms of O. mykiss welfare and low MP oxidation rates. In general, we can say that T3 group fillets are more sensitive to oxidative damage, while T1 and T2 groups give better results in maintaining meat quality with low MP oxidation rates.     

Thermal stability study of SDC/Na2CO3 nanocomposite electrolyte for low-temperature SOFCs

The novel core–shell nanostructured SDC/Na₂CO₃ composite has been demonstrated as a promising electrolyte material for low-temperature SOFCs. However, as a nanostructured material, stability might be doubted under elevated temperature due to their high surface energy. So in order to study the thermal stability of SDC/Na₂CO₃ nanocomposite, XRD, BET, SEM and TGA characterizations were carried on after annealing samples at various temperatures. Crystallite sizes, BET surface areas, and SEM results indicated that the SDC/Na₂CO₃ nanocomposite possesses better thermal stability on nanostructure than pure SDC till 700 °C. TGA analysis verified that Na₂CO₃ phase exists steadily in the SDC/Na₂CO₃ composite. The performance and durability of SOFCs based on SDC/Na₂CO₃ electrolyte were also investigated. The cell delivered a maximum power density of 0.78 W cm⁻² at 550 °C and a steady output of about 0.62 W cm⁻² over 12 h operation. The high performances together with notable thermal stability make the SDC/Na₂CO₃ nanocomposite as a potential electrolyte material for long-term SOFCs that operate at 500–600 °C.     

Effect of lysine incorporation,annealing and heat moisture treatment alone and in combination on the physico-chemical,retrogradation, rheological properties and in vitro digestibility of kithul (Caryota urens L.) starch

Physico-chemical, retrogradation, rheological properties and in vitro digestibility of lysine incorporated kithul starch modified by annealing, heat moisture treatment and its combinations were studied. LS-AHMT (annealed-heat moisture treated lysine incorporated kithul starch) exhibited lowest amylose leaching. LS-AHMT showed significantly (P ≤ 0.05) higher relative crystallinity. LS-ANS (annealed lysine incorporated kithul starch), LS-HMT (heat moisture treated lysine incorporated kithul starch) and LS-AHMT formed more weak gel by the effect of annealing, heat moisture treatment and its combination. LS-AHMT showed lowest pasting viscosities, G′ and G″ values among the modified kithul starch, which indicates its lower retrogradation properties. In vitro digestibility of kithul starch decreased after modifications and LS-ANS, LS-HMT and LS-AHMT showed significantly higher resistant starch content. The current study showed that annealing, heat moisture treatment and its combination on NS-LS (lysine incorporated kithul starch) effectively modified kithul starch properties.     

The effects of ozone,ultrasound and coating with shellac and lysozyme–chitosan on fresh egg during storage at ambient temperature – part 1: interior quality changes

The objective of this research was to investigate and compare the effect of different treatments including gaseous ozone (6-ppm/4-min), ultrasound (450 W/4 min) and coating of shellac, lysozyme–chitosan (L-C) on fresh eggs internal quality during storage for six weeks at ambient temperature. The internal quality attributes such as weight loss (WL), albumen viscosity, Haugh unit (HU), yolk index, total soluble solids, albumen and yolk's pH were monitored. Control groups had the worst HU (50.04), WL (8.35%), albumen pH (9.27) and viscosity (7.72 mPa·s) values after storage. The best interior qualities were obtained by shellac coating [HU (72.37), WL (1.37) and viscosity (30.10 mPa·s)] and sonication (albumen pH: 8.22). Thus, the shellac-coated eggs maintained all the internal quality parameters at the highest values, while the ozone and ultrasound only helped to keep the internal quality and enhance the shelf life of eggs.