by T. Ram Mohan Rao, G. Venkata Rao, k.Sreenivasa Rao & A.Purushottam

Welding process is common in manufacturing industry especially for car component assembly. The demand on vehicles in development contry has push the SMIs to contribute the economic forward.The purpose of this study is to monitor the toxic gases level in the welding process in SMIs. The case study was done in two car component manufacturer which is a supply for national car. The data from monitoirng process was analyze and compare with the regulation and standards. Futhermore from the monitoring process, the data will used as a baseline for the furthur action as a need to comply with the regulation set-up by the government. The monitoring as a key of the occupational safety and health(OSH) approach in welding process to improve the quality of work environment has significanlty evaluated.

In Round Robin Scheduling, the time quantum is fixed and then processes are sched­uled such that no process get CPU time more than one time quantum in one go. If time quantum is too large, the response time of the processes is too much which may not be tolerated in interactive environment. If time quantum is too small, it causes unneces­sarily frequent context switch leading to more overheads resulting in less through­put. In this paper, a method using integer programming has been proposed to solve equations that decide a value that is neither too large nor too small such that every process has reason­able response time and the throughput of the system is not de­creased due to unneces­sarily context switches.

The effect of rice mill wastewater on the growth, reproduction and metabolism of Drawida willsi, Michaelsen earthworm was studied under laboratory conditions. Prior to the experiment, the physicochemical characteristics of the rice mill wastewater were measured. The wastewater revealed an alkaline pH (8.0) with low concentration of DO (0.9 mg l^-1), nitrate (0.5 mg l^-1), phosphate (21 mg l^-1) and sulphate (40 mg l^-1), moderate concentration and COD (630 mg l^-1), chloride (140 mg l^-1) and TDS (670 mg l^-1), and high concentration of total suspended solids (530 mg l^-1) and BOD (450 mg l^-1).  Moreover, the wastewater was rich in sodium (235 mg l^-1), total phenols (35 mg l^-1) as well as silica (58 mg l^-1). Drawida willsi is a dominant earthworm (>80% both in number and biomass) in the crop fields of India and therefore was used as the test specimen. A 96-hour toxicity test of juvenile immature and adult age groups of D. willsi was conducted in different concentrations of rice mill wastewater, both by suspension and artificial soil methods. The toxicity test revealed no mortality of any age groups of D. willsi even at 100% wastewater. Experiments on growth, reproduction and metabolism were, therefore conducted up to 100% wastewater (0, 25, 50, 75 and 100%) for a period of 105 days to assess the suitability of rice mill wastewater for agricultural purpose.  Growth of D. willsi earthworm showed significant increase in 50% wastewater treated soil and it was significantly reduced, when the concentration of wastewater irrigation exceeded a level of 75%. Like growth, the peak as well as average rate of reproduction of D. willsi was stimulated up to 50% wastewater treated soil. Both the rates were significantly dropped at or above 75% wastewater treated soil. In addition to this, D. willsi exhibited a delay in reproductive peak by 15 days in 75 and 100 % wastewater treated soil. Unlike growth and reproduction, the respiratory and excretory activities of D. willsi did not show any significant change up to 50 % rice mill wastewater irrigated soil. A remarkable increase in metabolic activities was observed from 75% wastewater treated soil and the increase was maximal at the highest concentration tested (100%). However, in control as well as wastewater treated soil, the rate of respiration of D. willsi went on decreasing, as the earthworm grew older up to 105 days. The adverse effect of rice mill wastewater on growth, reproduction and metabolism at higher concentrations may be due to alkaline pH (8.0). Besides pH, other parameters like higher contents of polyphenols, silica and sodium in wastewater were also responsible to impede the growth, reproduction and metabolism of D. willsi in soil. However, in diluted concentrations of rice mill wastewater (i.e. up to 50%), significant increase in growth and reproduction with little or no change in metabolism was noticed. This may be due to the fact that at lower concentrations, the toxic substances being in diluted form stimulating the growth and reproduction of D. willsi in soil without causing any adverse effect to metabolism. So on the basis of our findings, we suggest that rice mill wastewater should be either diluted to at least 50% or treated to make it suitable for agricultural purpose.