|SCIENCE TRIBUNE||Thursday, June 5, 2003, Chandigarh, India|
In the present era of rapid urbanisation, over-population and unabated industrial growth all around the world, a constant need to shift focus from "development" to "sustainable development" has repeatedly been felt. Last decade saw the holding of Earth Summit at Rio de Janeiro and the world realised the importance of preserving the environment and maintaining the eco-system in which it prospers. New ozone holes, global warming, polluted waters, barren lands, lifeless forests, greenhouse effect and toxic atmosphere were noted to be the visible negative impacts of manís relentless march without caring for the environment. It became evident that for the survival of both the human beings and the animal world, efforts to minimise environmental degradation were needed to be accelerated by every country, every industry and every individual.
Today, rules and regulation demand safe disposal of affluents by the industries without causing any adverse effect upon air, water or soil. Setting up an environment management cell has become essential for every industry. Monitoring the pollution control aspects is a fullfledged job, needing a strong organisational setup and a testing infrastructure. There may be instances when some industrial units may have escaped the eye of the law and continued to discharge the affluents without their treatment but such an approach may result in heavy losses in the long run. With the passage of time, the rules, the control and the penalties are going to be heavier only. It is therefore a better and wiser step for every industry to set up its own unit for Environment management, treat its affluents, discharge them safely and be free of the stress that will always keep lurking if these measures are not taken. Once an industry accepts the fact that saving the environment is an integral part of its production process and whatever little or large expenditure it needs is unavoidable, the double-mindedness and the perplexity come to an end.
Any industry, may be a production unit or a generation unit, has to ensure that its operations do not affect :
1. Air Quality.
2. Water Quality.
3. Soil Quality.
4. Noise Levels.
Every industry releases air and water affluents during its operation and produces noise. Air affluents affect air quality, water affluent affects water and soil quality and noise affects physiological and psychological states of living beings. To keep the pollutants contained by the affluents within permissible limits, air and water need to be sampled, analysed and treated while the noise levels are to be kept low. In addition, every industry has to evolve a plan to add greenery and plantation to the area in and around that industry. Since the industries are run on a continuous basis, time intervals at which the affluents are to be sampled and analysed are to be decided keeping in view the quantum of discharge and an environment management cell needs to be created accordingly to carry out the job.
Chart 1 shows the setting up of an environment management cell in an industry. The cell should work out the number of stations required to draw the samples of air, water and soil and the number of stations to measure the noise levels. It should also draw a landscaping and arboriculture plan to add greenery to the area occupied by the industry, to monitor the progress of the new plants and to keep a record of effect of pollutants on the plantation. This cell should further assess the number of samples to be drawn and the intervals at which the air, water and soil samples are to be collected at the decided stations. Thereafter, the process of collection of samples, their analysis, the comparison of percentage of pollutants contained in the samples with the corresponding permissible limits and the conveyance of results to the concerned units of the industry for corrective measures should be a regular process carried out in an immaculate manner without allowing the laxity to set in over the passage of time.
An environment Management cell should fully equip itself with the necessary testing equipment, samplers, chemicals for testing, equipment to record climatic conditions and noise level meters. High Volume samplers to suck air through a glass fibre filter paper, respirable particulate samplers, electronic balance for air quality; pH meter, conductivity meter, BOD incubator, COD apparatus, Turbidity meter and Magnetic stirrer for Water Quality and Precision Integration Sound Level meters to measure sound pressure levels should form essential part of the equipment handy to the environment management cell.
Table 1 shows the air affluent components to be monitored and Table 2 shows the water affluent pollutants that need to be measured and controlled. Table 3 shows various parameters for soil quality monitoring. Every industry needs to tick the parameters to be checked with respect to the nature of its affluents and initiate the monitoring process accordingly.
I have noticed that at certain speeds, in some conditions of lighting, the blades of a fan seem to be moving in a direction opposite to their actual direction of motion. How does it happen?
I suspect that you notice this at night when your room is illuminated by florescent lighting. In the household electric current the light intensity of a florescent tube fluctuates at the rate of about 50 times a second. This is not ordinarily noticed. But take a scale and move it back and forth in front of the light at a fast speed. You will notice that the scale seems to be broken up in bands. This is due the variation of intensity I have mentioned above. Such variations would also be there, but with a much smaller - almost imperceptible - amplitude even when you are viewing with an incandescent lamp. Essentially, in fluorescent lighting you see the world under a strobe light. Any regular motion, like the motion of blades of the fan, would be modulated by the strobe frequency. This effect is rather similar to the one we see while looking at the image of the wheels of car while seeing a film or on TV. You would notice the wheels going backward during a slow start or stop of the car, because of the strobe effect produced by the film or TV frame rate of about 24 per second.
Since we are all made of the same stuff why are some people more intelligent than others?
All living things, including plants, are made up of roughly the same material. What makes them living is that they have a capability of self-replication - they can make babies and multiply. The information that controls their growth resides in their DNA. These instructions are detailed but they are written in a language that is the same for all life. The instructions that make each of us come from our inherited genes. These genes contain the contribution of both the parents. Therefore it is not surprising that there would be some difference between us. We may have basically the same architecture and similar ways of growing, but we do look different ó we even behave differently.
Even siblings differ because the embryos from which they grew might not be exactly the same. It is possible, therefore, that there would be differences in the brain sizes and configuration between different individuals. The capabilities of the brain also grow. The pattern of growth may depend on physical and cultural factors. But in essence there is little difference between the intelligence of two healthy individuals, even though a slight edge does matter. The point to appreciate is that even though we come from the same material, the combination of the same genes, we are not like coins stamped out by a machine. Chance and statistics also come into play during inheritance.
When we pour water over quick lime it emits heat. How does it happen?
All chemical reactions involve an exchange of energy, some of which often manifests itself in terms of heat.
Quick lime is calcium
oxide, which is prepared by heating limestone to a temperature of the
order of 900 degrees Celsius. The reaction produces, in addition, carbon
dioxide. When calcium oxide, or quick lime, is mixed with water a
chemical reaction occurs producing calcium hydroxide and a lot of heat.
The chemists say that the reaction is highly exothermic. Therefore the
answer to your question is that here you are talking of a highly
exothermic chemical reaction. Incidentally calcium hydroxide is the
chemical name of slaked lime, that is used for white washing our walls
and some people eat in their "paan".