Characterization study on the variation of weight percentage of Alumina Aluminum in-situ Particulate reinforced composite material

IN-SITU Al2O3 SiC C having 20 wt%, 25 wt%, 30 wt% and 35wt% of powdered particulate were fabricated by liquid metallurgy (stir cast) method. The composite specimens were machined as per test standards. The specimens were tested to know the common casting defects using image analyzer. Some of the mechanical properties have been evaluated and compared with Al6061 alloy. Significant improvement in uniform distribution of particulates is noticeable as the wt % of the flake particles increases. The microstructures of the composites were studied to know the dispersion of the powdered particles in the matrix. It has been observed that addition of flake particles significantly improves particulate distribution

Photodegradation of methyl red by advanced and homogeneous photo-​Fenton's processes: A comparative study and kinetic approach

The degrdn. of methyl red (MR)​, an azo dye, was carried out by the homogeneous photo-​Fenton's process (HPFP) and the advanced photo-​Fenton's process (APFP) using sym. peroxides such as hydrogen peroxide and ammonium persulfate (APS) as oxidants. The APFP showed higher efficiency than their homogeneous counterparts even at high dye concns. due to the faster redn. of Fe3+ to Fe2+ ions on the iron surface. H2O2 proved to be a better oxidant for both the processes. However, APS efficiently inhibited the pptn. of iron oxy hydroxides at higher dosage of iron powder compared to H2O2 by providing excess acidity to the reaction medium. The rate const. for the kinetics of decolorisation by various oxidn. processes is of the order: Fe0/H2O2/UV > Fe0/H2O2/dark > Fe0/APS​/UV > Fe2+/H2O2/UV > Fe0/UV > Fe0/APS​/dark > Fe0/dark ≈ H2O2/UV > Fe2+/APS​/UV > APS​/UV > Fe2+/H2O2/dark > Fe2+/APS​/dark ≈ Fe2+/UV. The degrdn. reaction was followed by UV-​visible and GC-​MS spectroscopic techniques. Based on the intermediates obtained, probable degrdn. mechanisms have been proposed. It was found that the initial mechanism in the APFP involves the redn. of azo groups to amines while in the case of HPFP it leads to the formation of hydroxylated products due to the oxidn. of azo groups

Photo-degradation of Di Azo Dye Bismarck Brown by Advanced photo-Fenton Process: Influence of Inorganic Anions and Evaluation of Recycling Efficiency of Iron Powder

The present research work has demonstrated the usage of zero valent metallic iron (ZVMI) in the photo-Fenton process under UV light as a promising and novel technique for the complete degradation of di azo dye Bismarck Brown (BB) in aqueous medium. The influence of various reaction parameters like concentration of oxidants/dye/iron powder and pH of the solution was investigated and optimum conditions are reported. Ammonium persulfate (APS) proved to be better oxidant in comparison with hydrogen peroxide for enhancing the degradation rate and effectively inhibited the precipitation of iron hydroxides at higher dosages of iron powder which is attributed to the acidity provided by APS which is crucial for Fenton process. The rate constant for the kinetics of degradation using various oxidation processes follows the order: Fe0/APS/UV > Fe0/H2O2/UV > Fe0/APS/dark > Fe0/UV > Fe0/H2O2/dark > Fe0/dark > H2O2/UV > APS/UV. The effects of inorganic anions that are commonly found in the industrial effluents like NaCl, KNO3, Na2SO4, Na2CO3 and NaHCO3 at different concentrations on the degradation rate were studied in detail. The degradation was followed by UV-vis and GC-MS techniques

Crop diversification in black pepper gardens with tuber and fodder crops

With an objective to augment the income from black pepper plantation by intercropping tuber and fodder crops, a field experiment was conducted in RBD at Ambalavayal (Kerala) for two years 2007 to 2009. Based on yield performance , tuber crops such as cassava, elephant foot yam , coleus, and spices like ginger and turmeric, and fodder crops viz. hybrid napier grass, guinea grass, congo signal grass were selected as treatments apart from a control (sole crop of black pepper). The results indicated that higher black pepper yield was obtained under intercropping situation compared to sole crop. The maximum black pepper equivalent yield (1,147 kg/ha) was recorded by elephant foot yam followed by ginger (956 kg/ha). In the case of fodder crops, maximum pepper equivalent yield was recorded by hybrid napier grass Co 3 (2,633 kg/ha) followed by guinea grass (2,347 kg/ha). Maximum net return of ` 2, 70, 230/ ha was obtained from black pepper + elephant foot yam followed by black pepper + ginger (` 2, 60,657/ ha). Among the fodder crops, hybrid napier grass recorded maximum net return (` 2, 05,950/ ha) followed by guinea grass. Benefit: cost ratio was higher for inter cropping hybrid napier grass (3.7) followed by ginger (3.5) and elephant foot yam (3.4) in black pepper gardens

Influence of various aromatic derivatives on the advanced photo Fenton degradation of Amaranth dye

The photo degrdn. of Amaranth (AR) dye by advanced photo Fenton process in the presence of sym. peroxides like hydrogen peroxide (H2O2) and ammonium persulfate (APS) are investigated. The influence of various reaction parameters like the effect of iron dosage, concn. of H2O2/APS, initial dye concn., effect of pH and the influence of various arom. derivs. were studied and optimum conditions are reported. The efficiency of the oxidant was strongly influenced by the nature of arom. photoproducts formed during the course of the degrdn. reaction. To study their effect on the rate of degrdn. these arom. derivs. were added in known concn. (10 ppm)​. The influence of various arom. derivs. on the degrdn. kinetics shows the following order: hydroquinones > chlorophenol > dichlorobenzene > arom. carboxylic acids > anilidine > nitrophenol. The addn. of these derivs. did not influence the degrdn. pathway although it altered the reaction rate. The percentage COD and TOC removal were detd. in presence of arom. derivs. to evaluate the complete removal of the pollutant. Based on the intermediates obtained in the UV-​vis and GC-​MS spectroscopic techniques probable degrdn. mechanism has been proposed

Biomineralisation performance of bacteria isolated from a landfill in China

We report an investigation of microbially-induced carbonate precipitation by seven indigenous bacteria isolated from a landfill in China. Bacterial strains were cultured in a medium supplemented with 25 mM calcium chloride and 333 mM urea. The experiments were carried out at 30 °C for 7 days with agitation by a shaking table at 130 rpm. Scanning Electron Microscopic (SEM) and X-ray diffraction (XRD) analyses showed variations in calcium carbonate polymorphs and mineral composition induced by all bacterial strains. The amount of carbonate precipitation was quantified by titration. The amount of carbonate precipitated in the medium varied among isolates with the lowest being Bacillus aerius rawirorabr15 (LC092833) precipitating around 1.5 times more carbonate per unit volume than the abiotic (blank) solution. Pseudomonas nitroreducens szh_asesj15 (LC090854) was found to be the most efficient, precipitating 3.2 times more carbonate than the abiotic solution. Our results indicate that bacterial carbonate precipitation occurred through ureolysis and suggest that variations in carbonate crystal polymorphs and rates of precipitation were driven by strain-specific differences in urease expression and response to the alkaline environment. These results and the method applied provide benchmarking/screening data for assessing the bioremediation potential of indigenous bacteria for containment of contaminants in landfills

Next-generation sequencing showing potential leachate influence on bacterial communities around a landfill in China

The impact of contaminated leachate on groundwater from landfills is well known but specific effects on bacterial consortia are less well-studied. Bacterial communities in landfill and an urban site located in Suzhou, China were studied using Illumina high-throughput sequencing. A total number of 153944 good quality reads were produced and sequences assigned to 6388 operational taxonomic units (OTUs). Bacterial consortia consisted of up to 16 phyla including Proteobacteria (31.9 to 94.9% at landfill, 25.1 to 43.3% at urban sites), Actinobacteria (0 to 28.7% at landfill, 9.9 to 34.3% at urban sites), Bacteroidetes (1.4 to 25.6% at landfill, 5.6 to 7.8% at urban sites), Chloroflexi (0.4 to 26.5% at urban sites only) and unclassified bacteria. Pseudomonas was the dominant (67-93%) genus in landfill leachate. Arsenic concentrations in landfill raw leachate (RL) (1.11x103 µg/L) and fresh leachate (FL2) (1.78x103 µg/L), and mercury concentrations in RL (10.9 µg/L) and FL2 (7.37 µg/L) were higher than Chinese State Environmental Protection Administration (SEPA) standards for leachate in landfills. Shannon diversity index and Chao 1 richness estimate showed RL and FL2 lacked richness and diversity when compared with other samples. This is consistent with stresses imposed by elevated arsenic and mercury and has implications for ecological site remediation by bioremediation or natural attenuation

Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2015: A systematic analysis for the Global Burden of Disease Study 2015

Background: The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform debates on the importance of addressing risks in context. Methods: We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defined criteria for convincing or probable evidence. We extracted relative risk and exposure estimates from randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. We developed a metric that allows comparisons of exposure across risk factors—the summary exposure value. Using the counterfactual scenario of theoretical minimum risk level, we estimated the portion of deaths and DALYs that could be attributed to a given risk. We decomposed trends in attributable burden into contributions from population growth, population age structure, risk exposure, and risk-deleted cause-specific DALY rates. We characterised risk exposure in relation to a Socio-demographic Index (SDI). Findings: Between 1990 and 2015, global exposure to unsafe sanitation, household air pollution, childhood underweight, childhood stunting, and smoking each decreased by more than 25%. Global exposure for several occupational risks, high body-mass index (BMI), and drug use increased by more than 25% over the same period. All risks jointly evaluated in 2015 accounted for 57·8% (95% CI 56·6–58·8) of global deaths and 41·2% (39·8–42·8) of DALYs. In 2015, the ten largest contributors to global DALYs among Level 3 risks were high systolic blood pressure (211·8 million [192·7 million to 231·1 million] global DALYs), smoking (148·6 million [134·2 million to 163·1 million]), high fasting plasma glucose (143·1 million [125·1 million to 163·5 million]), high BMI (120·1 million [83·8 million to 158·4 million]), childhood undernutrition (113·3 million [103·9 million to 123·4 million]), ambient particulate matter (103·1 million [90·8 million to 115·1 million]), high total cholesterol (88·7 million [74·6 million to 105·7 million]), household air pollution (85·6 million [66·7 million to 106·1 million]), alcohol use (85·0 million [77·2 million to 93·0 million]), and diets high in sodium (83·0 million [49·3 million to 127·5 million]). From 1990 to 2015, attributable DALYs declined for micronutrient deficiencies, childhood undernutrition, unsafe sanitation and water, and household air pollution; reductions in risk-deleted DALY rates rather than reductions in exposure drove these declines. Rising exposure contributed to notable increases in attributable DALYs from high BMI, high fasting plasma glucose, occupational carcinogens, and drug use. Environmental risks and childhood undernutrition declined steadily with SDI; low physical activity, high BMI, and high fasting plasma glucose increased with SDI. In 119 countries, metabolic risks, such as high BMI and fasting plasma glucose, contributed the most attributable DALYs in 2015. Regionally, smoking still ranked among the leading five risk factors for attributable DALYs in 109 countries; childhood underweight and unsafe sex remained primary drivers of early death and disability in much of sub-Saharan Africa. Interpretation: Declines in some key environmental risks have contributed to declines in critical infectious diseases. Some risks appear to be invariant to SDI. Increasing risks, including high BMI, high fasting plasma glucose, drug use, and some occupational exposures, contribute to rising burden from some conditions, but also provide opportunities for intervention. Some highly preventable risks, such as smoking, remain major causes of attributable DALYs, even as exposure is declining. Public policy makers need to pay attention to the risks that are increasingly major contributors to global burden. Funding: Bill & Melinda Gates Foundation