Influence of transient porosity in a coupled fracture-skin-matrix system at the scale of a single fracture

Environmental Science and Pollution Research - The subsurface leaching of soluble chemicals in a fractured porous medium poses long-term risk of groundwater contamination. Tracing the occurrence,...     

Remediation of tetracycline pollution using MXene and nano-zero-valent iron materials: a review

Environmental Chemistry Letters - Antibiotic resistance is a major health issue partly caused by the diffusion of antibiotic pollution in the natural environment, thus calling for advanced methods...     

Scanning electron microscopy study of the gills,scales and erythrocytes of Anabas testudineus upon exposure to chlorpyrifos

The present study was undertaken to assess the toxicity of sublethal concentrations (125, 250, and 375 µg L^?1) of chlorpyrifos on Anabas testudineus for 21 days. The morphological changes on the gills, scales, and erythrocytes of A. testudineus were observed using scanning electron microscopy. Gill alterations included highly active mucous cells, epithelial hyperplasia, and fusion of secondary lamellae. The scales showed damaged lepidonts. Oozed out cytoplasmic content and lobopodial projections were observed in the erythrocytes after exposure to chlorpyrifos.     

Real-world vehicle emissions: a summary of the Sixteenth Coordinating Research Council On-Road Vehicle Emissions Workshop

The Coordinating Research Council held its 16th workshop in March 2006, with 83 presentations describing the most recent mobile source-related emissions research. In this paper, we summarize the presentations from researchers who are engaged in improving our understanding of the contribution of mobile sources to air quality. Participants in the workshop discussed evaluation of in-use emissions control programs, effects of fuels on emissions, emission models and emission inventories, results from gas- and particle-phase emissions studies from spark-ignition and diesel-powered vehicles, and efforts to improve our capabilities in performing on-board emissions measurements, as well as topics for future research.     

Prevalence of certain inorganic constituents in groundwater samples of Erode district, Tamilnadu, India, with special emphasis on fluoride, fluorosis and its remedial measures

A total of 60 drinking water samples collected from Erode district, Tamilnadu, India were analysed for fluoride contamination, besides water quality parameters such as pH, electrical conductivity, total dissolved solids, total alkalinity, total hardness, fluoride, bicarbonates, calcium, magnesium, nitrate, sulphate, phosphate, sodium and potassium. The results obtained were found to exceed the permissible limits. The concentration of fluoride in the water samples ranged between 0.5 and 8.2 mg/l and revealed that 80% of the water samples contain fluoride above the maximum permissible limit. Similarly, the concentrations of nitrate, hardness, calcium and magnesium in some samples were also more than the permissible level. Pearson’s correlation coefficient among the parameters showed a positive correlation of fluoride with total hardness and calcium. It is inferred from the study that these water sources can be used for potable purpose only after prior treatment.     

Toxicity,uptake, and accumulation of nano and bulk cerium oxide particles in <Emphasis Type="Italic">Artemia salina</Emphasis>

Although the toxicological impact of metal oxide nanoparticles has been studied for the last few decades on aquatic organisms, the exact mechanism of action is still unclear. The fate, behavior, and biological activity of nanoparticles are dependent on physicochemical factors like size, shape, surface area, and stability in the medium. This study deals with the effect of nano and bulk CeO₂ particles on marine microcrustacean, Artemia salina. The primary size was found to be 15 ± 3.5 and 582 ± 50 nm for nano and bulk CeO₂ (TEM), respectively. The colloidal stability and sedimentation assays showed rapid aggregation of bulk particles in seawater. Both the sizes of CeO₂ particles inhibited the hatching rate of brine shrimp cyst. Nano CeO₂ was found to be more toxic to A. salina (48 h LC₅₀ 38.0 mg/L) when compared to bulk CeO₂ (48 h LC₅₀ 92.2 mg/L). Nano CeO₂-treated A. salina showed higher oxidative stress (ROS) than those treated with the bulk form. The reduction in the antioxidant activity indicated an increase in oxidative stress in the cells. Higher acetylcholinesterase activity (AChE) was observed upon exposure to nano and bulk CeO₂ particles. The uptake and accumulation of CeO₂ particles were increased with respect to the concentration and particle size. Thus, the above results revealed that nano CeO₂ was more lethal to A. salina as compared to bulk particles.     

Integration of DFE and DFMA for the sustainable development of an automotive component

The recent developments in manufacturing organizations recognize sustainability as an important value addition for survival in the competitive scenario. The design engineers are in search of approaches for creating environmental conscious products. The purpose of this paper is to report a research carried out for ensuring sustainable product design by the integration of Design for Environment (DFE) and Design for Manufacture and Assembly (DFMA) methodologies. In this context, this paper reports a case study carried out in an automotive component. The candidate product is the charge alternator pulley. The existing pulley has been created using Computer Aided Design. Then sustainability analysis was conducted on the existing component for determining environmental impact. This is followed by the engineering analysis of the component using ANSYS. Then conceptual design changes were developed in the proposed product using DFMA concept. Then the environmental impact has been evaluated in terms of carbon footprint, energy consumption and air/water impacts on proposed product. It has been found that the optimized pulley design possesses minimal environmental impact. The result of the case study indicated that the integration of DFE and DFMA concept could initiate new developments in sustainable designs with minimal impact to the environment and it also reduces the product cost.     

Toxic effect of different types of titanium dioxide nanoparticles on Ceriodaphnia dubia in a freshwater system

Environmental Science and Pollution Research - In the current study, the effect of different types of titanium dioxide (TiO2) nanoparticles (NPs) (rutile, anatase, and mixture) was analyzed on...