Fabrication,physiochemical and optoelectronic characterization of SiO2/CdS core–shell nanostructures

Silica/CdS core–shell nanostructures have been developed using a simple wet chemical route. This method utilizes silica spheres formation followed by successive ionic layer adsorption and reaction method assisted CdS shell layer formation. The morphological studies revealed the uniformity in size distribution with core size of 250 nm and shell thickness of 9 nm. The electron microscopic images also indicate the irregular morphology of CdS shell layer. The structural studies indicate the simple cubic system of CdS shell with no other trace for impurities in the crystal structure. This CdS layer exhibit the band gap energy of 2.66 eV, due to weak quantum confinement and numerous defects presence. The studies on room temperature photoluminescence measurement indicate the emission properties and the corresponding electronic energy levels of defect states. Further, the physiochemical understanding of core–shell formation mechanism clearly matches with the motive behind the defects present in the CdS shell layer.     

Thermal performance of V-trough solar air heater with the thermal storage for drying applications

It was analysed the thermal performance of V-trough solar air heater with the thermal storage for drying applications. An active V trough solar air heater having concentration ratio of 1.5 with the thermal energy storage is designed and fabricated by using the flat plate non-selective surface embedded by paraffin wax based thermal energy storage. The developed system is tested by thermal performance test at site having the latitude of 12.97° N and longitude of 77.57° E over the period of time with and without the thermal storage. It was found that the incorporation of thermal storage is gives 10% higher thermal performance than without the thermal storage and other existing flat plate air heater. The total cost of the system is INR.30834/- and it saves conventional fuels and saves environment. It was concluded that the proposed system will be more economical if it was hybridized with utilization of the renewable energy sources of heat or waste heat.     

Keratin hydrolysate as an exhausting agent in textile reactive dyeing process

Salt is an essential exhausting agent for the dyeing of cotton fabric with reactive dyes. The usage of salt leads to an increased effluent load in terms of total dissolved solids and also limits the opportunities for recycling textile dye house effluents. These effluents are difficult to degrade and their disposal leads to environmental pollution. In the present work, we have prepared keratin hydrolysate (KH) from waste of wool processing industries to reduce the usage of salt in dyeing. The KH was fixed to the cotton fabric at five different add on percentage, and the presence of the KH on the fabric was confirmed by FTIR, TGA and SEM-EDX Studies. The KH-fixed fabrics were further dyed with reactive dyes without addition of salt. The colour strength of the fabric increased up to 91 % to that of the control sample. The studies reveal that the tone of the fabric was not altered and KH usage can significantly reduce salt consumption in reactive dyeing process.     

Magnetic Tweezers‐Based 3D Microchannel Electroporation for High‐Throughput Gene Transfection in Living Cells

A novel high‐throughput magnetic tweezers‐based 3D microchannel electroporation system capable of transfecting 40 000 cells/cm² on a single chip for gene therapy, regenerative medicine, and intracellular detection of target mRNA for screening cellular heterogeneity is reported. A single cell or an ordered array of individual cells are remotely guided by programmable magnetic fields to poration sites with high (>90%) cell alignment efficiency to enable various transfection reagents to be delivered simultaneously into the cells. The present technique, in contrast to the conventional vacuum‐based approach, is significantly gentler on the cellular membrane yielding >90% cell viability and, moreover, allows transfected cells to be transported for further analysis. Illustrating the versatility of the system, the GATA2 molecular beacon is delivered into leukemia cells to detect the regulation level of the GATA2 gene that is associated with the initiation of leukemia. The uniform delivery and a sharp contrast of fluorescence intensity between GATA2 positive and negative cells demonstrate key aspects of the platform for gene transfer, screening and detection of targeted intracellular markers in living cells.     

Studies on cellulose acetate–polysulfone ultrafiltration membranes: I. Effect of polymer composition

Ultrafiltration techniques have particular advantages for simultaneous purification, concentration and fractionation of macromolecules. Studies are presented on novel ultrafiltration membranes, based on cellulose acetate and polysulfone blends, for the separation of proteins and heavy metal ions. The effects of polymer composition on pure water flux, water content, molecular weight cut‐off and hydraulic resistance are discussed. Scanning electron microscopy images of the membranes show the presence of segregated individual domains of cellulose acetate and polysulfone. The molecular weight cut‐off obtained from the protein separation studies is also presented. Applications of these membranes for separating metal ions from aqueous streams are discussed. Copyright © 2005 Society of Chemical Industry     

Site‐specific delivery of green tea coated aluminium magnesium silicate beads and studies on their effect against chicken coccidiosis

In this report, the site‐specific co‐delivery of green tea/aluminium magnesium silicate (AMS) was reported and the specific target delivery was achieved orally. The new co‐precipitation process was developed to synthesis the green tea/AMS hybrid complex and using energy‐dispersive X‐ray spectroscopy, Fourier‐transform infrared spectroscopy and Raman confirmed its successful synthesis. The blood biocompatibility of the green tea/AMS was tested using chicken blood, and the compound is safe up to 500 mg/ml. After mixed with hydroxypropyl methylcellulose phthalate, the oral beads were synthesised using a linking agent. The oral beads underwent different pH‐based dissolution studies and the results indicated that the beads specifically dissolved in gastric pH (6.5). The pharmaco kinetic studies were performed to estimate the delivery kinetics. The results revealed that the beads underwent as per the Higuchi model. The anticoccidial effects of the beads were tested using chicken. The animal studies were performed in two different modes such as prophylactic treatment and active treatment after Eimeria species challenge. The results indicated that the prophylactic treatment with beads 100% protected the chicken and the active treatment with beads after the Eimeria challenge significantly protected against the intestinal damage and it also enhanced the anticoccidial effect.Inspec keywords: X‐ray chemical analysis, drug delivery systems, pH, drugs, biomedical materials, blood, dissolving, Fourier transform infrared spectra, Raman spectra, aluminium compounds, magnesium compounds, precipitation (physical chemistry), materials preparationOther keywords: prophylactic treatment, active treatment, anticoccidial effect, green tea coated aluminium magnesium silicate beads, chicken coccidiosis, target delivery, Fourier‐transform infrared spectroscopy, blood biocompatibility, chicken blood, hydroxypropyl methylcellulose phthalate, oral beads, pharmacokinetic studies, delivery kinetics, animal studies, site‐specific codelivery, pH‐based dissolution, coprecipitation process, green tea‐AMS hybrid complex, energy‐dispersive X‐ray spectroscopy, Raman spectroscopy, linking agent, gastric pH, Al₂ Mg₃ O₁₈ Si₆ , intestinal damage, Eimeria species, anticoccidial effects, Higuchi model     

Factors Affecting Quality of Dried Low-Rank Coals

The chemical and physical properties of coal are strongly affected by the upgrading process employed. For high-moisture coals, upgrading involves thermal dehydration to improve the calorific value of the coal on mass basis. This study evaluates the feasibility of upgrading a low-rank/grade coal using the oven drying method. The objective of this research work is to study the drying characteristics of low-rank coals and to understand the factors affecting the quality of dried low-rank coals. This article describes laboratory experiments conducted on the characterization of the low-rank coals before and after the drying process. The results on drying kinetics, re-absorption of coal samples, and proximate analysis of coal samples before and after drying are discussed. It was found that the upgrading process produced coal with better heating value and combustion characteristics than those of the raw coal samples.     

Minimization of Moisture Readsorption in Dried Coal Samples

Low-rank coals csonstitute a major energy source for the future as reserves of such high-moisture coals around the world are vast. Currently they are considered undesirable since high moisture content entails high transportation costs, potential safety hazards in transportation and storage, and the low thermal efficiency obtained in combustion of such coals. Furthermore, low-moisture-content coal is needed for the various coal pyrolysis, gasification developed. Hence, various upgrading processes have been developed to reduce the moisture content. Moisture readsorption and spontaneous combustion are important issues in coal upgrading processes. This article discusses results of laboratory experiments conducted to study the options for minimization of readsorption of moisture after drying of selected coal samples. Results suggest that there is little benefit in drying low-rank coal at high temperatures. It was found that the higher the amount of bitumen used for coating, the lower is the readsorption of moisture by dried coal. Also, mixing high-temperature-dried coal with wet coal in appropriate proportion can yield reduced moisture content as the sensible heat in the hot coal is utilized for evaporation.