Hydrogeochemical investigations to assess groundwater and saline water interaction in coastal aquifers of the southeast coast,Tamil Nadu,India

Environmental Science and Pollution Research - Groundwater and saline water interaction is the most common processes in the coastal aquifers that alters the quality of aquifer waters. The...     

Spatio-temporal assessment of ambient air quality,their health effects and improvement during COVID-19 lockdown in one of the most polluted cities of India

Environmental Science and Pollution Research - The present work aims to investigate seasonal variations in air pollution levels in Lucknow and assess the ambient air quality of the city together...     

Urban environment alter the timing of progression of testicular recrudescence in tree sparrow (Passer montanus)

Environmental Science and Pollution Research - Urbanization is a rapidly growing phenomenon that affects wildlife. Laboratory studies show the effects of night light on the physiology of the...     

Economic and environmental impact analyses of hybrid generation system in respect to Rajasthan

Environmental Science and Pollution Research - This paper intends to show the aspects of an environment-friendly hybrid energy system (HES) for reducing the electrical power problems in remote...     

Seasonal variation and sources of carbonaceous species and elements in PM2.5 and PM10 over the eastern Himalaya

Environmental Science and Pollution Research - The study represents the seasonal characteristics (carbonaceous aerosols and elements) and the contribution of prominent sources of PM2.5 and PM10 in...     

Effect of start of main injection timing on performance,emission, and combustion characteristics of a VGT CI engine fueled with neem biodiesel

The performance of engine parameters is more influenced with fuel injection strategies namely start of main injection timing (SoMI). An experimental analysis was performed to find the optimum SoMI timing based on performance, emission, and combustion characteristics. Base fuel of diesel and neem biodiesel was used as test fuels. The neem biodiesel was prepared by esterification and transesterification process. It is found from literature that neem biodiesel blend NB20 with diesel gives optimum performance and emission characteristics; therefore, NB20 blend was used for experiments. A variable geometry turbocharger (VGT) compression ignition (CI) engine was used to conduct the experiments. Engine performance parameters were estimated and compared with a base fuel of diesel and with NB20 blends. In this experimentation, fuel injection pressure (FIP) of 800 bar and engine speed of 1700 rpm were considered. SoMI timing was varied from 2° to 10° bTDC with an increment of 2° bTDC timing. Cylinder pressure (CP) and heat release rate (HRR) were estimated and found that are higher for diesel fuel compared to NB20 blend at different SoMI timings. The addition of neem biodiesel NB20 blend to diesel fuel decreases the exhaust emissions except NOx emissions. The BSFC was considerably reduced and BTE was improved almost equivalent to the diesel fuel for NB20. From the results, it is concluded that 10° bTDC SoMI timing provides 13% improvement in BTE, 21% decrement in BSFC, and 7.5% reduction in CO₂ emissions.

     

Comparison of fuel characteristics of hydrotreated waste cooking oil with its biodiesel and fossil diesel

Environmental Science and Pollution Research - Compression ignition engines powered by diesel are the work horses of developing countries like India. However, burning fossil fuel causes a lot of...     

Effect of electrostatic precipitator on exhaust emissions in biodiesel fuelled CI engine

Environmental Science and Pollution Research - The exhaust emissions from the compression ignition engines are harmful to both human beings and the environment. After-treatment devices placed in...     

A modeling study of fouling development in membrane bioreactors for wastewater treatment.

Membrane fouling is a primary concern in membrane bioreactors (MBRs) in wastewater treatment because it strongly affects both system stability and economic feasibility. A mathematical model was developed in this study for membrane fouling in submerged MBR systems for wastewater treatment, in which both reversible and irreversible fouling were quantified. While mixed liquor suspended solids are the major components of the reversible fouling layer, dissolved organic matter is thought to be the key foulant, in particular, responsible for the long-term irreversible fouling of the filtration unit. The model was calibrated (parameter identification) with a set of operational data from a pilot MBR and then verified with other independent operational data from the MBR. The good agreement between theoretical predictions and operational data demonstrates that the outlined modeling concept can be successfully applied to describe membrane fouling in submerged MBR systems.     

An analytical force model for orthogonal elliptical vibration cutting technique

The elliptical vibration cutting (EVC) technique has been found to be a promising technique for ultraprecision machining of various materials. In each overlapping EVC cycle, the thickness of cut (TOC) of work material, and the tool velocity get continuously varied. These two inherent phenomena, in fact, introduce transient characteristics into its cutting mechanics, which are considered to be different from the one applied for conventional cutting technique. Recently, a few theoretical models have been developed to understand the material removal mechanism with the EVC technique; however, in those studies, the transient phenomena were not considered. In the present research, an analytical force model for the orthogonal EVC process was developed in order to fully understand the EVC mechanism, and to more accurately predict the transient cutting force values. Three important factors: (i) transient TOC, (ii) transient shear angle, and (iii) transition characteristic of friction reversal were investigated and analyzed mainly based on geometric modeling and the Lee and Shaffer's slip-line solution. Mathematical evaluation shows that they may have significant influence on EVC process, and thus on its output performance. In order to validate the proposed force model, a series of low-frequency orthogonal EVC tests were conducted. The experimental transient cutting force values were compared with the predicted values calculated using the proposed model, and they are found to be in a good agreement with each other.