Effect of chemical preservatives on shelf life of mushroom (Pleurotus ostreatus) cultivated on cassava peels

Short shelf life is a major impediment to the processing and distribution of mushroom. The effect of chemical preservatives on some quality attributes of mushroom during storage was investigated. Mushroom were soaked in four preservatives at two concentrations for 10 mins, packaged, stored at 4 °C for 30 days and analysed at intervals for their microbial population, colour, firmness and weight loss. Sodium benzoate (0.05%, 0.1%) lost its preservative effect on all the micro‐organisms enumerated after 3 days, and samples treated with 0.1% potassium sorbate had the lowest microbial load at the end of the storage period. Change in colour of the potassium sorbate (0.1%)‐treated sample was lower than and significantly different from the citric acid (2%, 4%)‐treated samples. The values of the firmness of the 4% citric acid preserved mushroom were significantly different (P ≤ 0.05) from other samples throughout the storage period. There was a significant negative correlation (r = ?0.807, P < 0.01) between the firmness and weight loss of the preserved mushroom. Potassium sorbate (0.1%) and citric acid (4%) extended the shelf life of mushroom for 24 days.     

Effect of low‐zinc status and essential fatty acids deficiency on the activities of aspartate aminotransferase and alanine aminotransferase in liver and serum of albino rats

The effects of dietary deficiencies of zinc and essential fatty acids (EFAs) or both on aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were investigated in young growing rats. Four groups of albino rats were fed diets deficient in either EFA (4% hydrogenated coconut oil) or zinc (6 ppm) or both. The control diet was adequate in EFA (4% soybean oil) and zinc (100 ppm). The feeding trial lasted eight weeks and the activities of AST and ALT were determined in the liver and serum. EFA deficiency had no significant (p > 0.05) effect on liver AST. However, zinc and the double deficiencies depressed AST activity in the organ. Deficiencies of EFA, zinc and their combination depressed ALT activity in the liver significantly (p < 0.05) with a concomitant increase recorded in the serum. The data suggested alteration in endothelial permeability of the plasma membrane and thus leakage of membrane constituents in the tissue studied. It is therefore considered that these deficient diets may affect liver tissue negatively in view of the role of these enzymes in amino acid metabolism.     

Effect of recrystallization temperature and time on the AA1060 aluminum alloy

The thermal treatment of cold rolled aluminum 1060 produced by the continuous casting method has been found to produce defective cups lacking in height during cupping. The annealing process involves heating to 480°C for 6 h and stepping down to 420°C for 2 h, to evolve a microstructure with good mechanical properties that will enhance material formability. This study presents an appropriate heat treatment procedure that depends on crystal ordering and on the chemistry of the alloy. These have significant influence on the recovery process and consequently the response of the material to deep drawing. This heat treatment procedure will reduce energy/power consumption and hence operating costs and increase the life span of thermo-process facilities.     

Development of Effective Therapeutic Molecule from Natural Sources against Coronavirus Protease

The SARS-CoV-2 main protease (M^pro) is one of the molecular targets for drug design. Effective vaccines have been identified as a long-term solution but the rate at which they are being administered is slow in several countries, and mutations of SARS-CoV-2 could render them less effective. Moreover, remdesivir seems to work only with some types of COVID-19 patients. Hence, the continuous investigation of new treatments for this disease is pivotal. This study investigated the inhibitory role of natural products against SARS-CoV-2 M^pro as repurposable agents in the treatment of coronavirus disease 2019 (COVID-19). Through in silico approach, selected flavonoids were docked into the active site of M^pro. The free energies of the ligands complexed with M^pro were computationally estimated using the molecular mechanics-generalized Born surface area (MM/GBSA) method. In addition, the inhibition process of SARS-CoV-2 Mpro with these ligands was simulated at 100 ns in order to uncover the dynamic behavior and complex stability. The docking results showed that the selected flavonoids exhibited good poses in the binding domain of M^pro. The amino acid residues involved in the binding of the selected ligands correlated well with the residues involved with the mechanism-based inhibitor (N3) and the docking score of Quercetin-3-O-Neohesperidoside (−16.8 Kcal/mol) ranked efficiently with this inhibitor (−16.5 Kcal/mol). In addition, single-structure MM/GBSA rescoring method showed that Quercetin-3-O-Neohesperidoside (−87.60 Kcal/mol) is more energetically favored than N3 (−80.88 Kcal/mol) and other ligands (Myricetin 3-Rutinoside (−87.50 Kcal/mol), Quercetin 3-Rhamnoside (−80.17 Kcal/mol), Rutin (−58.98 Kcal/mol), and Myricitrin (−49.22 Kcal/mol). The molecular dynamics simulation (MDs) pinpointed the stability of these complexes over the course of 100 ns with reduced RMSD and RMSF. Based on the docking results and energy calculation, together with the RMSD of 1.98 ± 0.19 Å and RMSF of 1.00 ± 0.51 Å, Quercetin-3-O-Neohesperidoside is a better inhibitor of M^pro compared to N3 and other selected ligands and can be repurposed as a drug candidate for the treatment of COVID-19. In addition, this study demonstrated that in silico docking, free energy calculations, and MDs, respectively, are applicable to estimating the interaction, energetics, and dynamic behavior of molecular targets by natural products and can be used to direct the development of novel target function modulators.     

Particulate matter emission and K/S/Cl transformation during biomass combustion in an entrained flow reactor

This study aims to demonstrate the effect of ash chemistry, especially, the transformation of potassium (K), chlorine (Cl), and sulfur (S) species, on the fine particle emission during biomass combustion. Biomass was burned in an entrained flow reactor at varied temperature from 1000 to 1300 °C, where fine particles were sampled using a 13-stage low pressure impactor, and the morphology and composition of the fine particles were analyzed. The fates of K, Cl, and S during biomass combustion were compared between the entrained flow reactor and the muffle furnace. Results show that the particle size distributions of PM₁₀ are bimodal for all studied cases. A higher concentration of fine-mode particle is observed at 1000 °C, with the peak position at 0.274 μm. When the temperature is increased from 1000 to 1100 °C or higher, the concentration of fine-mode particle is reduced by about 50%, and its size becomes smaller with a peak position at 0.097 μm. K, Cl and S are enriched as potassium chloride and sulfate, dominantly in PM_1.0; while Mg, Ca and Si are enriched in PM_1.0–10. A certain amount of sulfur in PM_1.0 at 1000 °C is observed, while the sulfur disappears above 1100 °C. This indicates that the process of potassium sulfation tends to occur at a moderate temperature, and affects the emission amount and the particle size distribution of particulate matters. Analyzing results of the fates of K, Cl and S in the particle phase indicate a completed sulfur-release from biomass ash above 1200 °C, as well as a maximum capture efficiency for potassium-containing vapors at 1100 °C, which results in a minimum PM_1.0 emission at 1100 °C.     

Robust designs for generalized linear models with possible overdispersion and misspecified link functions

We discuss robust designs for generalized linear models with protection for possible departures from the usual model assumptions. Besides possible inaccuracy in an assumed linear predictor, both problems of overdispersion and misspecification in link function are addressed. For logistic and Poisson models, as examples, we incorporate the variance function prescribed by a superior model similar to a generalized linear mixed model to address overdispersion, and adopt a parameterized generalized family of link functions to deal with the problem of link misspecification. The design criterion is the average mean squared prediction error (AMSPE). The exact optimal design, which minimizes the AMSPE, is also presented using examples on the toxicity of ethylene oxide to grain beetles, and on Ames Salmonella Assay.     

Retort carbonization of bamboo (Bambusa vulgaris) waste for thermal energy recovery

Clean Technologies and Environmental Policy - Production of biochar from bamboo (Bambusa vulgaris) is a potential route to recover thermal energy from biomass. This study presents a preliminary...     

Cracking Susceptibility After Post-Weld Heat Treatment in Haynes 282 Nickel Based Superalloy

This paper presents a study of the standard post-weld heat treatment （PWHT） behaviour of autogenous laser welded γ＇ age-hardenable precipitation strengthened nickel based superalloy Haynes 282 （HY 282）. The study involves a careful and detailed microstructural characterisation as well as an analysis of the weld cracking susceptibility during welding and Gleeble thermo-mechanical physical simulation. Various factors that could influence post-weld cracking in superalloys weld were experimentally examined. Our microstructural exami- nation of the as-solution heat treated （SHTed） material and the thermo-mechanically refined grain material shows that intergranular heat affected zone （HAZ） cracking is observable in only the as-welded SHTed material. There was no indication of post-weld heat treatment cracking in all welded materials. Our conclusion, in this study, is that the chemistry of superalloy HY 282 which aids the preclusion/formation of deleterious so- lidification microconstituents during welding as well as its relatively slow aging kinetics enhances its resistance to PWHT cracking.