2,4-dinitroanisole transformation during advanced oxidation with ultraviolet light emitting diodes and hydrogen peroxide

This study investigated the kinetics and reaction mechanisms associated with advanced oxidation of 2,4-dinitroanisole (DNAN) with light emitting diodes (LEDs) in the UV/H₂O₂ process. The pseudo first-order reaction rate constants for DNAN oxidation depended on the H₂O₂/DNAN molar ratio and were between 0.017 and 0.026 min⁻¹. Hydroxyl radical scavenging was strongly implicated by the experimental results. High mass spectrophotometric chromatograms showed the presence of several by-products, including three with ecotoxicity that is greater than that of DNAN. Transformation pathways were analysed using Density Functional Theory (DFT), which helped to predict the presence of experimentally detected DNAN by-products by considering Mulliken charges. This study is the first to elucidate DNAN transformation mechanisms using both experimental studies and computational chemistry.     

Retrieval of thermal properties in a transient conduction–radiation problem with variable thermal conductivity

This article reports an inverse analysis of a transient conduction–radiation problem with variable thermal conductivity. Simultaneous retrieval of parameters is accomplished by minimizing the objective function represented by the square of the difference between the measured and the assumed temperature fields. The measured temperature field is calculated from the direct method involving the lattice Boltzmann method (LBM) and the finite volume method (FVM). In the direct method, the FVM is used to obtain the radiative information and the LBM is used to solve the energy equation. With perturbations imposed on the measured temperature data, minimization of the objective function is achieved with the help of the genetic algorithm (GA). The accuracies of the retrieved parameters have been studied for the effects of the genetic parameters such as the crossover and the mutation rates, the population size, the number of generations and the effect of noise on the measured temperature data. A good estimation of parameters has been obtained.     

Experimental determination of thermal conductivity of three nanofluids and development of new correlations

Experimental investigations have been carried out for determining the thermal conductivity of three nanofluids containing aluminum oxide, copper oxide and zinc oxide nanoparticles dispersed in a base fluid of 60:40 (by mass) ethylene glycol and water mixture. Particle volumetric concentration tested was up to 10% and the temperature range of the experiments was from 298 to 363 K. The results show an increase in the thermal conductivity of nanofluids compared to the base fluids with an increasing volumetric concentration of nanoparticles. The thermal conductivity also increases substantially with an increase in temperature. Several existing models for thermal conductivity were compared with the experimental data obtained from these nanofluids, and they do not exhibit good agreement. Therefore, a model was developed, which is a refinement of an existing model, which incorporates the classical Maxwell model and the Brownian motion effect to account for the thermal conductivity of nanofluids as a function of temperature, particle volumetric concentration, the properties of nanoparticles, and the base fluid, which agrees well with the experimental data.     

Isolation and evaluation of a high H2-producing lab isolate from cow dung

Hydrogen producing bacterial strain was isolated from Indian cow dung and identified of the bacterial family Enterobacteriaceae. This lab isolate was differentiated from Citrobacter Y-19 at molecular level by using RAPD, PCR based technique, and OPO-03₄₆₀ and OPO-17₈₀₀ RAPD marker for this specific strain (lab isolate) was identified. Fermentative studies were investigated for important parameters, starting with pH of the culture, temperature, inoculum age and inoculum volume, initial substrate concentration and different substrates. Among different substrates, dextrose and sucrose were the preferred substrates for hydrogen production. The optimal starting pH of the culture was found to be 5.0. The H₂ production increased with increase in temperature up to 30 °C. The maximum value of H₂ production was recorded when inoculum volume was 12.5% of the culture broth and inoculum age was 14 h. Under batch fermentation conditions, the maximum hydrogen production rate and yield were 355.2 ml l⁻¹ h⁻¹ and 2.1 mol/mol glucose (conversion 35%), respectively. These results indicate that this lab isolate is an ideal hydrogen producer.     

Promotion of microcrystallization by argon in moderately hydrogen diluted silane plasma

Using argon as a diluent of SiH₄, undoped hydrogenated microcrystalline silicon (μc-Si:H) films, having σ_D10⁻⁵ S cm⁻¹, were prepared at a very high deposition rate of 36 Å/min. Micrograins were identified with several well-defined crystallographic orientations. The effect of variation of Ar-dilution on the electrical and structural properties of Si:H films were studied systematically. Addition of H₂ to the Ar-diluted SiH₄ plasma improved the network structure by eliminating defects, introducing structural reorientation and grain growth, although, reducing the deposition rate. Accordingly, highly conducting (σ_D10⁻³S cm⁻¹) undoped μc-Si:H film was achieved utilizing energy released by de-excitation of metastable state of Ar (denoted as Ar*), in association with network modulation by atomic hydrogen in the plasma.     

A review on biological control and metabolism of aflatoxin

The series of events that led to the discovery of aflatoxin as a potent carcinogen, its biosynthesis, mechanism of action, structure-function relationship provide interesting insight into the economical and technological factors involved in the development of an effective control measure for the toxin. Scientists all over the world are making continuous efforts to explore a generalized process of detoxification, which can bring down the toxin content in heterogenous commodities to a threshold level. In this article biological control methods with special emphasis on in vivo and in vitro enzymatic detoxification of aflatoxin have been reviewed. Future areas of research involving large-scale enzymatic detoxification and modified atmosphere storage are also discussed.     

Cocoa polyphenols accelerate vitamin B12 degradation in heated chocolate milk

The rate of vitamin B₁₂ loss was 3X greater in heated, chocolate‐flavoured milk than in unflavoured milk. Studies of B₁₂ stability in the presence of cocoa powder components were performed to identify the reactive agents. Cocoa polyphenols with a strong capacity both for reduction and for peroxide generation accelerated B₁₂ destruction as much as 20‐fold vs. polyphenols without both capacities. Polyphenols with both capacities include the cocoa polyphenol (+)‐catechin and oligomers thereof, but also the structurally related polyphenols gallic acid, caffeic acid and (?)‐epigallocatechin gallate. The demonstrated physical affinity of cocoa powder for B₁₂ was a significant factor in the destructive process. B₁₂ may exhibit decreased stability in heated, neutral pH, polyphenol‐fortified foods.     

Sensory evaluation of black pigmented rice (Oryza sativa cv. Poireton) wine fortified with probiotic Lactobacillus acidophilus ATCC 4356 and Lactobacillus sakei ATCC 15521 using fuzzy logic

Rice wine was prepared in the laboratory from a black pigmented rice (cv. Poireton) using standardized methodology. The wine was fortified with the probiotic strains Lactobacillus acidophilus ATCC 4356 and Lactobacillus sakei ATCC 15521 and allowed to undergo a storage period of 28 days at 4°C. These rice wines were compared with a commercial wine used as a standard reference wine. A panel consisting of 30 judges performed the sensory evaluation. The scores obtained were based on the quality attributes of colour, taste, aroma and alcoholic strength. Analysis of the sensory scores and ranking of the different samples were performed using fuzzy analysis. The quality attributes were also ranked according to their importance in the overall acceptability. Colour and alcoholic strength were accorded the highest importance, compared with aroma and taste, as quality attributes. The rice wines were rated as ‘not satisfactory’, ‘fair’, ‘medium’, ‘good’ and ‘excellent’ on the sensory scale. Out of the wines prepared, black pigmented rice wine fortified with L. acidophilus was the most acceptable and was ranked as ‘good’, which was also at par with the commercial wine. On the other hand, black pigmented rice wine fortified with L. sakei and black pigmented rice wine fortified with L. acidophilus and L. sakei were ranked in the ‘satisfactory’ category followed by the unfortified wine ranked in the ‘fair’ category. Copyright © 2015 The Institute of Brewing & Distilling     

Identification and molecular mechanisms of novel antioxidative peptides from fermented camel milk (Kachchi breed,India) with anti-inflammatory activity in raw macrophages cell lines

The investigation was aimed at assessing anti-inflammatory and antioxidative activities along with the release of peptides with antioxidative properties during the fermentation of camel milk by Lacticaseibacillus casei (NK9). Reverse-phase high-performance liquid chromatography (RP-HPLC) was used to separate the bioactive peptides of 3 and 10 kDa (permeates and retentates). Reverse-phase liquid chromatography–mass spectrometry (RPLC/MS) was used to identify and characterise the pure bioactive peptides, and the effect of fermented camel milk on inflammation produced by lipopolysaccharide (LPS)/endotoxin in RAW 264.7 (Ralph and William's cell line) was also examined. Furthermore, docking revealed that peptides (LLNEK and IYTFPQPQSL) were predicted to inhibit myeloperoxidase (nMPO) activity by engaging with different residues in and around the human myeloperoxidase (hMPO) active site.