Modeling the performance of “up-flow anaerobic sludge blanket” reactor based wastewater treatment plant using linear and nonlinear approaches—A case study

The paper describes linear and nonlinear modeling of the wastewater data for the performance evaluation of an up-flow anaerobic sludge blanket (UASB) reactor based wastewater treatment plant (WWTP). Partial least squares regression (PLSR), multivariate polynomial regression (MPR) and artificial neural networks (ANNs) modeling methods were applied to predict the levels of biochemical oxygen demand (BOD) and chemical oxygen demand (COD) in the UASB reactor effluents using four input variables measured weekly in the influent wastewater during the peak (morning and evening) and non-peak (noon) hours over a period of 48 weeks. The performance of the models was assessed through the root mean squared error (RMSE), relative error of prediction in percentage (REP), the bias, the standard error of prediction (SEP), the coefficient of determination (R²), the Nash-Sutcliffe coefficient of efficiency (E_f), and the accuracy factor (A_f), computed from the measured and model predicted values of the dependent variables (BOD, COD) in the WWTP effluents. Goodness of the model fit to the data was also evaluated through the relationship between the residuals and the model predicted values of BOD and COD. Although, the model predicted values of BOD and COD by all the three modeling approaches (PLSR, MPR, ANN) were in good agreement with their respective measured values in the WWTP effluents, the nonlinear models (MPR, ANNs) performed relatively better than the linear ones. These models can be used as a tool for the performance evaluation of the WWTPs.     

Formation of β-hairpins in l-Pro-Gly containing peptides facilitated by 3-amino benzoic acid

Designed β-hairpin peptides tolerate insertion of 3-amino benzoic acid (3-Aba) and also permit accommodation of both enantiomers of Pro-Gly turn motifs.     

The ring puckering vibrations in trimethylene oxide and trimethylene sulphide as studied by P.M.R. spectroscopy in a liquid crystalline medium

The P.M.R. spectra of trimethylene oxide and trimethylene sulphide dissolved in a nematic solvent have been investigated. The chemical shifts, the direct and the indirect spin-spin couplings were determined.

The interpretation of the direct couplings in terms of the molecular structure shows that the ring skeleton of these molecules is not rigidly planar due to ring puckering vibrations. Mean amplitudes for the vibrations are estimated assuming fixed values for the bond distances and for the HCH bond angles. The results obtained are in good agreement with the earlier microwave studies.     

Stereochemical control in the structures of linear δ,α‐hybrid tripeptides containing tetrahydrofuran amino acids

Structural and electronic properties of diastereomers of tetrahydrofuran amino acids (TAA) derived tripeptide, Boc‐TAA‐Leu‐Val‐OMe, are studied using density functional theory. Predicted secondary folding patterns with hydrogen bonded pseudocycles of different sizes in peptides containing (2R,5S)‐cis‐TAA and (2S,5R)‐cis‐TAA are confirmed by detailed NMR studies of both, and single crystal X‐ray analysis of the former. A novel unusual folding pattern emanating from three‐centered hydrogen bond is found in peptide with (2R,5S)‐cis relationship. Stereochemical control on the orientation of interacting sites is substantiated by structural analysis of the peptides. Using natural bonding orbital and atoms in molecules analyses, charge transfer interactions are analyzed. Copyright © 2010 John Wiley & Sons, Ltd.     

Ion-acoustic wave propagation in two species of ions plasmas

The plasma which consists of one species of electrons, one hot species and another cold species of ions has been considered. By using reductive perturbation method it has been shown that the nonlinear ion-acoustic waves in unmagnetized plasmas are governed by the Korteweg-de Vries equation. The mixture of hot species of ions as impurity in the plasmas has been discussed. The effects due to the presence of hot species of ions on the Landau damping has also been considered.     

Effect of P2O5 on the early stage crystallization of K-fluorrichterite glass-ceramics

The addition of 2 mol% P₂O₅ to stoichiometric K-fluorrichterite (KNaCaMg₅Si₈O₂₂F₂, KFR) has been reported to enhance the mechanical properties and improve the in vitro biocompatibility of this glass-ceramic by promoting the formation of enstatite and fluorapatite (FA). Here, the effect of further increasing the P₂O₅ concentration on phase evolution of KFR has been investigated. XRD data showed that mica crystallized in samples with 4 and 5 mol% P₂O₅ (GP4 and GP5, respectively) at 650 °C, but no diopside was detected at higher temperatures, in contrast with the general phase evolution in KFR based glass-ceramics. More importantly, however, the addition of ?4 mol% P₂O₅ induced phase separation of the glass into a silica glass matrix and phosphate rich droplets prior to crystallization. EDS traces taken from samples heat-treated at 600 °C, revealed that the silica glass matrix was deficient in Mg and unlikely to be the host for crystallization of mica. Conversely, the P₂O₅ rich regions contained excess Mg and were considered to be the host for the formation of mica and FA.     

Hardy-Sobolev-Maz'ya type equations in bounded domains

We study the regularity, Palais-Smale characterization and existence/nonexistence of solutions of the Hardy-Sobolev-Maz'ya equation in a bounded domain in RN where x∈RN is denoted as x=(y,z)∈Rk×RN−k and . We show different behaviors of PS sequences depending on t=0 or t>0.     

Exploring groundwater hydrochemistry of alluvial aquifers using multi-way modeling

A three-way data set pertaining to hydrochemistry of the groundwater of north Indo-Gangetic alluvial plains was analyzed using three-way component analysis method with the purpose of extracting the information on spatial and temporal variation trends in groundwater composition. Three-way data modeling was performed using PARAFAC and Tucker3 models. The models were tested for their stability and goodness of optimal fit using core consistency diagnostic and split-half analysis. Although, a two-component PARAFAC model, explaining 50.47% of data variance, yielded 100% core consistency, it failed to qualify the validation test. Tucker3 model (3, 3, 1) captured 55.18% of the data variance and yielded simple diagonal core with three significant elements, explaining 100% of the core variability. Interpretation of the information obtained through Tucker3 model revealed that the groundwater quality in Khar watershed is mainly dominated by water hardness and related variables, whereas, water composition of the dug wells is dominated by alkalinity and carbonate/bicarbonates. Moreover, shallow groundwater sources in the region are contaminated with nitrate derived from fertilizers application in the region. The shallow aquifers are relatively more contaminated during the post-monsoon season.     

Molineria recurvata Ameliorates Streptozotocin-Induced Diabetic Nephropathy through Antioxidant and Anti-Inflammatory Pathways

Molineria recurvata (MR) has been traditionally used to manage diabetes mellitus in India. However, the molecular mechanism of MR on the diabetic-induced nephropathy has not been clearly investigated. Thus, this study investigates the protective effects of the MR extract on nephropathy in streptozotocin (STZ)-induced diabetic rats. Diabetes was instigated by a single intraperitoneal injection of STZ (45 mg/kg) in male Sprague-Dawley rats. Once the diabetes was successfully induced, the MR extract (200 mg/kg/day) or metformin (200 mg/kg/day) was orally administered for 14 days. Renal function, morphology changes and levels of inflammatory cytokines were measured. Blood glucose concentrations were considerably reduced in STZ-induced diabetic rats following treatment with the MR extract. The administration of the MR extract substantially restored the abnormal quantity of the oxidative DNA damage marker 8-hydroxy-2′-deoxy-guanosine (8-OHdG), malondialdehyde, glutathione, oxidized glutathione, superoxide dismutase, catalase, interleukin (IL)-1β, IL-6, IL-10, and transforming growth factor-β (TGF-β). The urinary excretion of kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), selenium binding protein 1 (SBP1), and pyruvate kinase M2 (PKM2) was significantly reduced in diabetes rats after administration of the MR extracts. In the kidneys of STZ-induced diabetic rats, the MR extracts markedly downregulated the expression of fibronectin, collagen-1, and α-smooth muscle actin (α-SMA). In particular, the MR extracts markedly increased the level of SIRT1 and SIRT3 and reduced claudin-1 in the kidney. These results suggest that the MR extracts exhibits therapeutic activity in contrast to renal injury in STZ-induced diabetic rats through repressing inflammation and oxidative stress.