Optimization of inoculum to substrate ratio for bio-energy generation in co-digestion of tannery solid wastes

The inoculum to substrate (I/S) ratio is an important factor which influences the anaerobic digestion process. In this study, the effect of different I/S ratios on the performance of co-digestion of fleshings along with mixture of sludge generated during treatment of tannery wastewater was investigated. The parameters studied were biogas generation, volatile solids reduction, volatile fatty acid (VFA) production, and the stability of the digestion process based on VFA to alkalinity ratio was evaluated for various I/S ratios. Economical significance of I/S ratio as related to the volume of the anaerobic digester and the potential benefit of bio-energy generated are discussed in detail.     

Developing a hybrid PSO–ANN model for estimating the ultimate bearing capacity of rock-socketed piles

Neural Computing and Applications - Rock-socketed piles are commonly used in foundations built in soft ground, and thus, their bearing capacity is a key issue of universal concern in research,...     

Comparative characterization and cytotoxicity study of TAT-peptide as potential vectors for siRNA and Dicer-substrate siRNA

Recently, a newly discovered Dicer-substrate siRNA (DsiRNA) demonstrates higher potency in gene silencing than siRNA but both suffer from rapid degradation, poor cellular uptake and chemical instability. Therefore, Tat-peptide was exploited to protect and facilitate their delivery into cells. In this study, Tat-peptide was complexed with siRNA or DsiRNA through simple complexation. The physicochemical properties (particle size, surface charge and morphology) of the complexes formed were then characterized. The ability of Tat-peptide to carry and protect siRNA or DsiRNA was determined by UV-Vis spectrophotometry and serum protection assay, respectively. Cytotoxicity effect of these complexes was assessed in V79 cell line. siRNA-Tat complexes had particle size ranged from 186?±?17.8 to 375?±?8.3?nm with surface charge ranged from ?9.3?±?1.0 to +13.5?±?1.0?mV, depending on the Tat-to-siRNA concentration ratio. As for DsiRNA-Tat complexes, the particle size was smaller than the ones complexed with siRNA, ranging from 176?±?8.6 to 458?±?14.7?nm. Their surface charge was in the range of +27.1?±?3.6 to +38.1?±?0.9?mV. Both oligonucleotide (ON) species bound strongly to Tat-peptide, forming stable complexes with loading efficiency of more than 86%. These complexes were relatively non cytotoxic as the cell viability of ～90% was achieved. In conclusion, Tat-peptide has a great potential as siRNA and DsiRNA vector due to the formation of stable complexes with desirable physical characteristics, low toxicity and able to carry high amount of siRNA or DsiRNA.     

Effect of ozonation and ultrasonication pretreatment processes on co-digestion of tannery solid wastes

Studies were carried out by the application of ozonation and ultrasonication as pretreatment processes on primary and secondary sludge generated during treatment of tannery wastewater to enhance the soluble chemical oxygen demand (SCOD). Further, co-digestion (simultaneous digestion of two or more substrates) studies were carried out in batch reactors using the fleshings (a solid waste generated during the processing of raw hides or skins into finished leather) along with the primary and the secondary sludge wherein biogas generation was compared with and without pre-treated sludge using ozone and ultrasonication processes, respectively. It was found that, application of pretreatment processes enhanced biogas generation by 45% in the case of ozone pre-treated sludge and 53% by ultrasonication processes, respectively, in conjunction with the fleshings. However, considering the optimum contact time required, application of ultrasonication as a pretreatment process was found to be the most appropriate and viable process to enhance the SCOD. This pretreatment process has the potential for implementation in tanneries using the shortest possible ultrasonication time to minimize energy cost when compared with ozonation time.     

New correlations for estimation of monthly average daily solar radiation on a horizontal surface using meteorological data

This study deals with the estimation of monthly average daily global solar radiation incident on a horizontal surface at a location using meteorological data for different cities of Andhra Pradesh state. The regression equations of two types of models are developed for various locations of the state having varied climatic regions using measured meteorological parameters obtained from different measuring stations. Parameters such as the latitude and height of the location, maximum and minimum temperature and relative humidity are considered to develop linear and quadratic regression equations to estimate the monthly average daily global radiation. The estimated values are compared with measured data and with other theoretical models in terms of mean percent errors calculated using recognised statistical criteria of MBE, MABE, MPE and RMSE. The proposed quadratic model performs better than the proposed linear models and shows good agreement with the long-term pyranometer data of various locations with a deviation of less than 10%. In comparison with other theoretical models presented so far, the suggested models are expected to perform with a higher degree of accuracy.     

Constructing porous ZnO/SnO2 nanocomposites for the detection of methane at low operating temperature

Journal of Porous Materials - Aimed at detecting methane (CH4) gas at low operating temperature, porous ZnO/SnO2 nanocomposites were constructed through a simple two-step method. Pure SnO2 with a...