Tuesday, February 19, 2019

REFORESTATION: NECESSITY AND POSSIBILTY


Why is reforestation important for a country like Nepal? How can it be made more effective than now? Which area of the country needs more focus in reforestation?

                        Reforestation refers to the simply plantation of the trees in the barren area and forests as well.  In other words reforestation means the regeneration of plant species which has been destroyed intentionally or naturally. Reforestation is actually the necessary task which must be accomplished by every people in the mother earth for their own existence. Since it is relevant that plant is the main source of life for the human being as the food and air are fundamental for humans and animals as well. But due to the exorbitant increase in population, the demand and desire of comfortability for human beings is increasing. For acquiring their own contentment, humans are destroying plants in relatively unmannered way. The plants are being cut down day to day and being implanted in very crucial ratio. This result in the increase in the barren area and most catastrophic affect to the environment. The scarcity or decrement of the trees leads to the numerous hazardous problem to humans like landslide, scarcity of pure air, desertification, climatic change, loss of wildlife, etc. thus the global warming and radiation problem is now being realized and making the human regret of their blunder.
                        In case of small country like Nepal which is considered as one of the stunning place of nature and beauty, the forests are one of the most important destination to be preserved, maintained and extended. But along with the rest of the world the deforestation is getting momentum. Large amount of areas are being deserted and some has already null. Due to the lack of awareness and appropriate laws and action, the forests are being destroyed day by day. Thus the reforestation is the most paramount action to be implemented in case of Nepal. Not only to make the country attractive but also to maintain the sound health and environment for the citizens, it in needed to control the deforestation and engage the peoples in the reforestation.
            Due to the affect of deforestation, numerous wildlife are extinct and some are in very critical phase. Withal the varieties of the medicinal herbs are extinct which inversely affect the economic situation of the country. The environmental disorder and climatic change has also the very long term problems which would be much more dangerous in the future generation. This may enhance the acid rainfall, depletion of ozone layer, etc. those problems can also affect the health of the human beings and may introduce new and deadliest diseases and other health problems. Thus it is very vital to make the afforestation in the country like Nepal to maintain its specialty and beauty.
            Witnessing the lethal consequences of deforestation, different practices and awareness programmes are being implemented in Nepal. Peoples in the rural areas and other marginalized peoples are taught about the harmfulness of deforestation and enhance them for afforestation. In addition many national and international INGOs and NGOs are being engaged in afforestation programmes and engaging peoples too. The laws and constitution are made for the forest and plant conservation. So that the no one can access the control over the forest on their desire. The theme of  “cut one tree and plant two” has been established and different environmentalist were engaged in providing the necessary education for environment conservation. 
            Some of the modification needs to be seen in the current strategies of different agencies because still the deforestation is in rapid ratio than that of afforestation. Peoples for their personal demand and desire are engaged in illegal cutting of trees. The increase in urbanization is affecting the forest directly or indirectly. Many theft is being done in the name of developmental works and other projects.  Forest are being the destination for the enjoyment, picnics and other informal tasks like camping, etc. these activities are not well managed which results in the forest-fire, illegal deforestation, etc. so those activities must be taken in account for conservation. Moreover the national parks and wildlife reserve must be continually detention time to time. Still numerous illegal activities are happening even inside the protected areas. The reforestation must be in higher ratio than the current since those programmes are still seen unprogressed fully. Still many place is being deserted and the afforested plants are not cared properly. Thus those action must be taken in account and the strategies need to be modified.
            Actually the afforestation not only to plant trees in the barren areas but also the restocking of the plants in the places where they used to be. The urbanization process is prevailing in the place of forest, so the plantation must also be done in the urban areas where there is the high pollution and busier. The afforestation programmes must also be practiced in the rural areas who are dependent on the forests for their livelihood. They must be prioritized and aware of the plantation of trees. Moreover the areas of bulk population like cities are must also be focused for afforestation since trees can absorb the pollution which may decrease the chance of vulnerable health problems. The deforestation during the developmental works must also be compensated by replanting. Some areas like charkoshe jhadi, raniwan, and other famous and big forest must be given priority and afforestation must be done. Most of the areas in terai has been encroached by the publics or refugees. Those place must be identified and properly managed and engage them to plant trees. Thus the every possible ways to afforestation will be succeed.

Monday, February 18, 2019


Study and explain other types of pollution like noise pollution, E-M pollution, radio-active radiation etc.

NOISE POLLUTION:
                                   
            Noise pollution, also known as environmental noise or sound pollution, is the propagation of noise with harmful impact on the activity of human or animal life. Generally the main source of the noise pollution are the high and bulky machineries and vehicles. The noise pollution is the result of unmanaged community and improper rules and regulation. Some noise pollution are intentional whereas some may be unintentional. The intentional pollution includes horn without its necessity, loud music, etc. moreover building construction, public programs, maintenance falls under the unintentional pollution. In addition Noise pollution associated with household electricity generators is an emerging environmental degradation in many developing nations. The average noise level of 97.60 dB obtained exceeded the WHO value of 50 dB allowed for residential areas. Research suggests that noise pollution is the highest in low-income and racial minority neighborhoods. Noise pollution induces the numerous types of short term and long term problems in the human beings and animals as well.
High noise levels can contribute to cardiovascular effects in humans and an increased incidence of coronary artery disease. In animals, noise can increase the risk of death by altering predator or prey detection and avoidance, interfere with reproduction and navigation, and contribute to permanent hearing loss. While the elderly may have cardiac problems due to noise, according to the World Health Organization, children are especially vulnerable to noise, and the effects that noise has on children may be permanent.  Noise poses a serious threat to a child’s physical and psychological health, and may negatively interfere with a child's learning and behavior.

 ELECTROMAGNETIC POLLUTION:

                   In our daily lives we are always in cope with the new and advanced technologies like mobile phones, computers, television, projectors, etc. These equipment extracts the harmful radiation namely electromagnetic radiation which are hazardous to the living being’s health. Moreover the humans and the animals are continuously exposed with the cosmic radiation and other unseen radiation in the atmosphere. In fact, animals and plants use electromagnetic radiation for a variety of their living activities e. g. communication, control and regulation of their various physiological, psychological and behavioral functions. Though essential for living organisms, exposure to excess such radiation beyond the naturally evolved tolerance limits causes various harmful effects in them. The effects of increased exposure to electromagnetic radiation on human, animal and plant bodies are now coming to light and are being increasingly studied. In addition, to study the health status and other medical and experimenting purposes, high amount of radiation is released.
                        The effects of extremely low-frequency electromagnetic radiations are dependent on dose and duration of exposure and are cumulative. It may take years of exposure before symptoms will appear. Usually symptoms of such electromagnetic pollution manifest as constant headaches, lack of energy, loss of appetite, mental blocks, decreased ability to concentrated, insomnia & sleep disturbances, palpitations, dizziness, trembling and rashes. After prolonged exposure, the symptoms may proceed to blackouts, nervous & psychological disorders like depression, feeling of being trapped, anxiety attacks, increased suicidal impulses, epilepsy, lowered libido & fertility, increased risk of arthritis and even cancer. White blood cells (WBC) are particularly sensitive to electromagnetic radiation and the risk of leukemia is increased in those areas where exposure to such radiations is high e.g. around power lines. Exposure to alternating magnetic fields accompanies exposure to electromagnetic radiations around power lines and from a variety of electrical appliances. Such exposure causes build up of serum triglycerides i.e. the fats found in blood stream that are implicated in heart diseases. Constant or frequent overexposure to such radiations may contribute to onset of heart problems.
                        Apart from human beings, a number of detrimental effects of electromagnetic radiations have also been observed on animals and plants. It has been observed that earthworms are distributed and move away from underground power cables. Hens living near power lines lay scrambled eggs in thin shells, bees seal up their hives and become aggressive, cows’ loose appetite and birds such as homing pigeons become disoriented. Plants exposed to electromagnetic radiation show disturbed root growth, seed germination, growth of pollen tubes, ion & water uptake and photosynthesis. Thus the appropriate action must be taken to eradicate or reduce the electromagnetic radiation.

RADIOACTIVE RADIATION POLLUTION:
                       
                        Radioactive pollution is defined as the increase in the natural radiation levels caused by human activities. It is estimated that about 20% of radiation we are exposed to is due to human activities. The human activities that can release radiation involve activities with radioactive materials such as mining, handling and processing of radioactive materials, handling and storage of radioactive waste, as well as the use of radioactive reactions to generate energy (nuclear power plants), along with the use of radiation in medicine (e.g. X-rays) and research. The radioactive decay generally deals with the chemical excess or as a byproduct unlike the electromagnetic radiation which is the usage of electric and electronics equipment. The radioactive radiation is the most harmful and catastrophic. This may results to the very
Sustaining problems which are very hard to reduce and controlled. The radioactive pollution are in the order of harmful to the most harmful. Most determining and dire radioactive pollution includes the nuclear fusion or fission.
                        Radioactive pollution is a vital ecological crisis. It could be much worse if extreme caution is not utilized in the handling and use of radioactive material, and in the design and operation of nuclear power plants. There are three basic tools that can provide protection against a radiation source. These are time, distance and shielding. The goal of the protection is to prevent over exposure from external radiation and to minimize the entry of radionuclides into the body or minimize internal radiation. Controlling Radiation Pollution can be done at various levels, such as usage and treatment of radiation waste, the control and mitigation of nuclear accidents, as well as the control and minimization of personal exposure to radiation at an individual level .Apart from being an inevitable series of negative effects of radiations, it is the duty of humans with regard to Radiation Standards Organizations to help in reducing the harmful effects of this kind of pollution.

LIGHT POLLUTION:

Light pollution, also known as photo pollution is an excessive use of artificial lights which shrinkage the value of original light.  The light pollution seems to be general but it is the most adverse agent which would deviate the human mankind into misleading destination  and the virtual world. As a major side-effect of urbanization, it is blamed for compromising health, disrupting ecosystems and spoiling aesthetic environments. Light pollution competes with the starlight during the night view, interferes with the astronomical studies, hampers certain animals surviving during night (nocturnal animals), and might decline the human ability of night visibility.
                                    Light pollution is a side-effect of industrial civilization. Its sources include building exterior and interior lighting, advertising, outdoor area lighting (e.g. car parks/parking lots), offices, factories, streetlights, and illuminated sporting venues. It is most severe in highly industrialized, densely populated areas of North AmericaEurope, and Japan and in major cities in the Middle East and North Africa like Tehran and Cairo, but even relatively small amounts of light can be noticed and create problems. Awareness of the deleterious effects of light pollution began early in the 20th Century, but efforts to address effects did not begin until the 1950s.  In the 1980s a global dark-sky movement emerged with the founding of the International Dark-Sky Association (IDA). There are now such educational and advocacy organizations in many countries worldwide.
                                                                                            -source: www.google.com
                                          


                       

Sunday, February 3, 2019

numericals of power plant equipments(mechanical part)



power plant equipment(mechanical part)

1.    A single cylinder engine operating at 2000 rpm develops a torque of 8 N-m. The indicated power of the engine is 2KW. Find the loss due to friction as the percentage of brake power.         (19.366%)
2.    An engine with 90% mechanical efficiency has rating of 38KW brake power. Estimate its indicated power and frictional power loss. Also determine the mechanical efficiency at quarter load assuming frictional power to remain same.       (42.22KW,4.22,69.24)         3.    A vertical single cylinder four stroke diesel engine has a bore=80 mm and stroke= 100mm. it develops a torque of 3.5 N-m. if the mechanical efficiency is 90%. Calculate the mean effective pressure of the engine.                            (97.22 Kpa)
4.    A diesel engine consumes fuel at the rate of 5.5 gm/sec and develops a power of 75KW. If the mechanical efficiency is 85%. The lower heating value if the fuel is 44MJ/kg. determine
a)    bsfc   (0.264kg/kwh)     
b)   isfc      (0.2244kg/kwh)
c)    Brake thermal efficiency    (31%)
d)   Indicated thermal efficiency    (36.36%)     
5.    A two stroke diesel engine was motored when the meter reading was 1.5 KW, then the test on the engine was carried out for one hour and following observations were recorded:
                    Brake torque=120 Nm                      Speed= 600 rpm          fuel used:2.5 kg              Cv=40.4 MJ/kg.Determine:                   a) brake power (7.54 KW)                                       b) indicated power (9.04 KW)                                       c) Mechanical efficiency (83.41%)                                            d) Indicated thermal efficiency   (32.30%)
6. In a test for four cylinder, four stroke engine has a diameter of 100mm, stroke=120 mm, speed of engine= 1800 rpm, fuel consumption of 0.2 kg/min, calorific value of fuel is 44000 KJ/kg. Difference in tension on either side of brake pulley=40kg, brake circumference is 300 cm. if the mechanical efficiency is 90%, determine
a) Brake thermal efficiency  (24.054)b) Indicated thermal efficiency (26.727)c) imep       (693.198 KPa)d) bsfc          (0.34 kg/kwh) 7. A gas turbine unit has a pressure ratio of 6 and maximum cycle temperature of 610 o C. the isentropic efficiencies if the compressor and turbine are 0.8 and 0.82 respectively. Determine the thermal efficiency and the power output in KW of an electric generator geared to the turbine when the air enters the compressor at 150 C at the rate of 16 kg/sec. take Cp = 1.11 KJ/kgK and ɼ=1.333 for the combustion and expansion process.    (12.24%, 770.56KW)


8. Air enters the compressor of an ideal air-standard Brayton cycle at 100 KPa, 300 K. the compressor pressure is 10. The turbine inlet temperature is 1400 K. determine the thermal efficiency of the cycle for a generator effectiveness of 80%. Take C=1.005 KJ/kgK and ɼ=1.4.                          (56.197%)
9. Air is drawn in a gas turbine unit at 15 degree Celsius. And 100 KPa and pressure ratio is 7. The compressor is driven by the HP turbine and LP turbine drives a separate power shaft. The isentropic efficiencies of compressor, and the HP and LP turbines are 0.82, 0.85, 0.85. If the maximum cycle temperature is 610 degree Celsius, calculate
      a) The pressure and temperature of the gases entering the low pressure turbine                (163.97 KPa, 654.76K)
b) The net power developed by the unit per kg per sec mass flow     ((74.378 KJ/kg)
c) The thermal efficiency of the unit
[for compression process Cpa= 1.005 KJ/kgK and ɼ=1.4 and for combustion and expansion processes: Cpg=1.15 KJ/kgK and ɼ=1.333)

10. Air enters the compressor at 100 KPA, 300 K and is compressed to 1000 KPa. The temperature at the inlet to the first turbine stage is 1400K. The expansion takes place isentropically in two stages, with reheat to 1400 K between the stages at constant pressure of 300 KPA. A regenerator having an effectiveness of 100% is also incorporated in the cycle. Determine the thermal efficiency. Take Cp= 1.005 KJ/kgK and r=1.4.                                                   (41.15%)

11. On a reheat cycle, steam leaves the boiler and enters the turbine at 4 MPa, 400 degree Celsius. After expansion in the turbine to 400 KPa, the steam is reheated to 400 degree Celsius and then expanded in the low pressure turbine to 10 KPa. Determine the cycle efficiency.                                                                 (35.87%)

12. a steam power plant running on Rankine cycle has steam entering HP turbine at 20 MPA, 500 degree Celsius and leaving LP turbine at 89.6% dryness. Considering condenser pressure of 0.005 MPA and reheating occurring up to the temperature of 500 degree Celsius. Determine:
                                a) The pressure at which steam leaves HP turbine   (1500 KPa)
                                b) The thermal efficiency             (44.417%)

13. a single running at 1800 rpm develops a torque of 8 N-m. the indicated power of the engine is 1.8 KW. Find the loss due to friction power as the percentage of IP.                                 (16.224%)

14. a 4-cylinder, 4 stroke cycle engine having cylinder diameter 100 mm and stroke 120 mm was tested at 1600 rpm and the following readings were obtained. Fuel consumption= 0.27 liters/minute, specific gravity of fuel= 0.74, BP= 31.4 KW, mechanical efficiency= 80%, Cv= 44000 KJ/kg. Determine
                                a) bsfc                                  (0.3817 kg/kwh)
                                 b) imep                             (780.854 KPa)
                                  c) brake thermal efficiency     (21.43 %)

15. A regenerative gas turbine with intercooling and reheat operates at steady state. Air enters the compressors at 1000 KPa, 300 K with a mass flow rate of 5.807 kg/sec. the pressure ratio across the two stage compressor is 10. The pressure ration across the two stage turbine is also 10. The intercooler and reheater each operate at 300 KPa. At the inlets to the turbine stages, the temperature is 1400 K. the temperature at the inlet to the second compressor stage is 300 K. the isentropic efficiency of each compressor and turbine stage is 80%. The regenerator effectiveness is 80%. Determine
                             a) Thermal efficiency
                              b) Back work ratio
                              c) Net power developed in KW
 [Take r=1.4, Cp=1.005KJ/kg]            (44.34%, 0.4655, 1957.496 KW)

16. Consider a regenerative cycle using steam as the working fluid. Steam leaves the boilers and enters the turbine at 4MPa, 400 degree Celsius. After expansion to 400 KPa, some of the steam is extracted from the turbine to heat the feed water in an open feed water heater. The pressure in the feed water heater is 400 KPa, and the water leaving it is saturated liquid at 400 KPa. The steam not extracted expands to 10 KPa. Determine the cycle efficiency.                (32.46%)
        
                                                                              Thank you!!!!!!!
                                                                                                 #paradox7


please like and subscribe my channel https://www.youtube.com/watch?v=T1SklxFbNoo&t=1s