Carminic acid modified anion exchanger for the removal and preconcentration of Mo(VI) from wastewater

Removal and preconcentration of Mo(VI) from water and wastewater solutions was investigated using carminic acid modified anion exchanger (IRA743). Various factors influencing the adsorption of Mo(VI), e.g. pH, initial concentration, and coexisting oxyanions were studied. Adsorption reached equilibrium within <10 min and was independent of initial concentration of Mo(VI). Studies were performed at different pH values to find the pH at which maximum adsorption occurred and was determined to be at a pH between 4.0 and 6.0. The Langmuir adsorption capacity (q(max)) was found to be 13.5mg Mo(VI)/g of the adsorbent. The results showed that modification of IRA743 with carminic acid is suitable for the removal of Mo(VI), as molybdate, from water and wastewater samples. The concentration of Mo(VI) was determined spectrophotometrically using bromopyrogallol red as a complexation reagent. This allows the determination of Mo(VI) in the range 1.0-100.0 μg/mL. The obtained material was subjected to efficient regeneration.     

Fermentation optimization for a probiotic local northeastern Indian rice beer and application to local cassava and plantain beer production

Response surface methodology was employed to determine the optimal conditions of time and temperature for the fermentation of a local North East Indian rice beer. The same conditions were then applied to prepare local beers from cassava (Manihot esculanta) and plantain (Musa ABB). Saccharomyces cerevisiae, Aspergillus oryzae and Lactobacillus plantarum were used to carry out the fermentation process. Thirteen experimental runs, based on a two‐factor five‐level design were carried out according to a central composite rotatable design. The independent variables were fermentation time (24–216 h) and temperature (25–40°C). The responses studied were content of protein, alcohol, total polyphenols, reducing sugars as well as titratable acidity and L. plantarum count. Numerical optimization predicted that a fermentation period of 143 h at a temperature of 33°C would result in a desirable rice beer, with response values of protein content OF 0.77%, alcohol content OF 6.99%, L. plantarum count of 7.08 log CFU mL^?1, polyphenol content of 34.46 mg/100 g, reducing sugars of 2.39% and a titratable acidity of 0.34%. Cassava and plantain beers were prepared using the optimized parameters of the rice beer experiments and the resultant beers exhibited the desired chemical parameters, suggesting applicability of the conditions to preparing these types of local beers from a wider range of substrates. Copyright © 2015 The Institute of Brewing & Distilling     

Selective coagulant recovery from water treatment plant residuals using Donnan membrane process

Fouling of membrane surfaces by particulate matter and large organic molecules is relatively common for pressure-driven membrane processes, namely, reverse osmosis (RO), nanofiltration (NF), and ultrafiltration (UF). Donnan membrane process (DMP) or Donnan Dialysis is driven by electrochemical potential gradient across a semipermeable ion exchange membrane. Theoretically, DMP is not susceptible to fouling by fine particulates and/or large organic molecules. According to information available in the open literature, however, DMP has not been tried to treat slurry or sludge with relatively high concentration of suspended solids or large organic molecules. This study presents the salient results of an extensive investigation pertaining to selective alum recovery from water treatment residuals (WTR) using DMP. Water treatment plants use alum, Al2(SO4)3 x 14H2O, as a coagulant, alum being finally converted and discharged as insoluble aluminum hydroxide along with natural organic matters (NOM), suspended solids, and other trace impurities. One commercial cation exchange membrane, namely Nafion 117 from DuPont Chemical Co., was used in the study for treating WTR obtained from two different water treatment plants in Pennsylvania. A series of laboratory tests confirmed that over 70% of alum is easily recoverable, and recovered alum is essentially free of particulate matter, NOM, and other trace metals. Most importantly, after repeated usage in the presence of high concentration of NOM and suspended solids, there was no noticeable decline in aluminum flux through the membrane, i.e., membrane surface fouling was practically absent. The DMP process involves coupled transport of Al3+ and H+ across the cation exchange membrane, and intramembrane transport was the rate-limiting step. Experimentally determined aluminum-hydrogen interdiffusion coefficient (D(Al-H)) values within the membrane were quite high (approximately 10(-6) cm2/s) under representative conditions, thus confirming high alum recovery rate. DMP was also found equally effective in recovering Fe(III) based coagulants from WTR.     

The impact of ratee's disability on performance judgments and choice as partner: The role of disability–job fit stereotypes and interdependence of rewards.

An experiment assessed the impact of disability job fit stereotypes and reward interdependence on personnel judgments about persons with disabilities. Students (N?=?87) evaluated 3 confederates. The experiment varied disability of the target confederate (dyslexia vs. nondisabled ), task, and dependence of rater rewards on partner performance. Two disability-task combinations represented stereotypical poor fit and good fit. Dependent variables were performance evaluations, performance expectations, and ranking of target as a partner. There was negative bias against the confederate with dyslexia in poor-fit conditions. In the interdependent reward condition, there was a negative main effect for disability, regardless of fit. No effects for disability were found on performance ratings or expectations. Results indicate the need to consider disability-job fit stereotypes and consequences to raters when assessing the impact of disability on personnel judgments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

fMRI neuroinformatics.

Functional magnetic resonance imaging (fMRI) generates vast amounts of data. The handling, processing, and analysis of fMRI data would be inconceivable without computer-based methods. fMRI neuroinformatics is concerned with research, development, and operation of these methods. Reconstruction, rudimentary analysis, and visualization tools are implemented in software controlling modern MRI scanners. Research in advanced methods for analysis of subtle activation patterns, realistic physiological modeling, or integration of data from multiple subjects is the basis for a lively research field and has led to the development of a large number of tools.     

Numerical assessment of hazard in compartmental fire having steady heat release rate from the source

The fire ignited due to air conditioner (A/C) malfunctioning is studied numerically for a single room, two rooms with interconnection, two interconnected rooms with attached corridor and a two-storeyed building with stairs. Coupled finite difference and finite volume based open source solver, Fire Dynamics Simulator (FDS) is used for domain discretization and solution of governing equations. Heat release rate per unit area (HRRPUA) is varied in the single room case and temperature and visibility contours are studied to determine HRRPUA corresponding to maximum hazard, judged based on available safe evacuation time (ASET) calculation. Further, positions of air conditioners, at a prescribed HRRPUA, are varied in two interconnected rooms to obtain the case with maximum ASET. Evacuation strategy is discussed and the maximum number of persons who can be safely evacuated from the accident site is calculated followed by the variation in the position of doors in the case with inter-connected doors attached with a corridor. Soot flow pattern and flame contours are also observed for each of the above cases. At the end, fire breakout is simulated in a two-storeyed building with stairs and having the room configuration based on the maximum ASET value.     

Improved infrared photoluminescence characteristics from circularly ordered self-assembled Ge islands

The formation of circularly ordered Ge-islands on Si(001) has been achieved because of nonuniform strain field around the periphery of the holes patterned by focused ion beam in combination with a self-assembled growth using molecular beam epitaxy. The photoluminescence (PL) spectra obtained from patterned areas (i.e., ordered islands) show a significant signal enhancement, which sustained till 200 K, without any vertical stacking of islands. The origin of two activation energies in temperature-dependent PL spectra of the ordered islands has been explained in detail.