Earth journey Research Paper Example | Topics and Well Written Essays - 250 words

Earth journey - Research Paper Example It is also safe to assume that the earth is maintaining these conditions to enable its survival (Lovelock 59). Times are changing and humans are changing for the better. This evolution demands that the earth change also, to ensure its survival, in the long run. The thing I found intriguing about the theory in question is the ability it has to assist scientists find out what needs to be done to salvage the situation. Documented proof that the earth is indeed protecting its existence is available. An example is the research conducted 15-20 years ago Lynn Margulis over the formation of clouds over the ocean. It is through the emission of sulphur molecules as waste material by algae, which later become raindrops through condensation. Cloud formation, in turn, assists the earth maintain its temperature while reducing the heat intensity from the sun (Lovelock 62). I would like to learn more about this theory. This is so that it may assist me in comprehending the benefits of modelling my activities to better suit my immediate environment, and the entire

Critical Assessment of a Book Essay Example | Topics and Well Written Essays - 1500 words

Critical Assessment of a Book - Essay Example Her greatest asset was a keen and observant biological eye which she made use of whenever she worked. Carson’s book ‘Silent Spring’ shot her to fame when it featured at the top of the bestseller lists. She was greatly encouraged by her mother to explore the natural world around her in which Rachel found immense solace. Her books were quite appealing due to their simplicity, style, lyrical value and thoroughness for which she was widely reviewed and honored. She adopted a visionary approach which was quite novel to the mainstream scientific community. Through her writing Rachel Carson handed down to us a legacy of scientific knowledge. She died on April 14th, 1964 at Silverspring, Maryland, USA. Part 2 Outline Structure of the Book   The book Silent Spring, written by Rachel Carson, was first published in the year 1962 and became an instant best seller. Silent Spring was written as a serial article for the magazine, The New Yorker but later was published as a boo k. Carson’s reputation as a writer and scientist helped in establishing the credibility of the book. This book had an enduring and enormous impact on the world. This book was not written for a narrow scientific audience but for the layman and it has been credited with kick starting a debate on the limits of technology, responsibility of science and the use of pesticides. She was of the view that "The best and cheapest controls for vegetation are not chemicals but other plants."  (pg.75) Carson meticulously described the process whereby the entire world food supply chain was contaminated by DDT. DDT entered the food chain and got accumulated in the fatty tissues of man and animal. A single application of the chemical on crops killed not only the targeted insects but also the other organisms present for weeks and months. These chemicals remained toxic even after dilution with rain water thereby causing irrevocable harm to animals and birds. "Carrots absorb more insecticide th an any other crop studied;...In the future it may become necessary to analyze soils for insecticides before planting certain food crops. Otherwise even unsprayed crops may take up enough insecticide merely from the soil to render them unfit for market."  (pg.59) The author implicitly states that these chemicals in the environment caused cancer. The scientist-author meticulously gathered evidence to show the adverse effect caused by the indiscriminate application of mineral based agricultural pesticides and synthetic phosphates and chlorinated hydrocarbons. She argued that not only was the environment being degraded but the very fabric of American natural beauty was being laid threadbare. The indiscriminate use of the chemicals resulted in the development of resistant strains. When they reached high levels of concentration in the water bodies it led to the death of aquatic flora and fauna. â€Å"It is not possible to add pesticides to water anywhere without threatening the purity of water everywhere. Seldom if ever, does nature operate in closed and separate compartments, and she has not done so in distributing the earth’s water supply.†(pg. 42) The efforts of Carson were rewarded when the Government of the United States of America regulated the use of pesticides by enacting the Federal Environmental Pesticide Control Act of 1972. Silent Spring is a book which still holds currency for the debate it still

Effect of Magnetic Field on Hydrodynamic Behavior

Effect of Magnetic Field on Hydrodynamic Behavior Effect of Magnetic Field on hydrodynamic behavior in a Microchannel Heat Sink Mohammad Nasiri 1*, Mohammad Mehdi Rashidi 2, 1 Department Mechanical Engineering, Faculty of Mechanical Engineering, University of Tabriz, Tabriz 5166616471, Iran 2 Department of Civil Engineering, School of Engineering, University of Birmingham, Birmingham, UK. ABSTRACT In this study, hydrodynamic behavior nanofluid (Fe3O4-water) in a MicroChannel Heat Sink (MCHS) with Offset Fan Shaped under magnetic field was numerically investigated. The two phase mixture model was used to simulate the nanofluid flow. Flow was assumed laminar, steady and incompressible. The effects of changing Reynolds number, power magnetic field, and nanoparticle diameter on fluid behavior are considered. The results show that the friction factor decreases and Nusselt number enhances whit rising Reynolds number. Whit increases intensity magnetic field the pressure drop, friction factor and Nusselt number increasing. The results indicate that non-uniform magnetic field has more effect on nanofluid behavior compare uniform magnetic field. Keywords Nanofluid; Microchannel heat sink; Magnetic field; Friction factor; Nusselt number Nomenclature ,z Cartesian coordinate axes Velocity component in x and y and z direction, respectively (m/s) (a,b) Center of magnetic wire (m) Velocity vector (m/s) 0 Velocity inlet (m/s) Acceleration vector (m/s2) Thermal conductivity (W/m K) Specific heat capacity at constant pressure Boltzmann constant (1.3806503ÃÆ'-10-23 J/K) Temperature (K) I Electric intensity (A) H Magnetic field intensity vector (A/m) Heat flux (1 MW/m2) Channel width (300ÃÆ'-10-6m) Hydraulic diameter (0.00001333 m) Channel length (2.70ÃÆ'-10-3m) Drag coefficient Mean velocity (m/s) Drift velocity (m/s) Slip velocity (m/s) d Mean diameter (nm) Nu= Nuselt number friction factor = Reynolds number Prandtlnumber Magnetic field (T) Greek symbols magnetic permeability in vacuum (4à Ã¢â€š ¬ÃƒÆ'-10-7 Tm/A) Dynamic viscosity (kg/m s) Thermal expansion coefficient(thermal expansion coefficient (K-1) Density (kg/m3) Mean free path (17ÃÆ'-10-9 m) Magnetic susceptibility Particle volume fraction Electrical conductivity (s/m) Subscripts Particle Base fluid bw Bottom wall Effective Average Introduction Nanofluids has higher thermal conductivities compared to them base fluids [1-5]. Currently the use of nanofluids in thermal engineering systems such as heat exchangers [6-7], microchannels [8-10] , chillers, medical applications [11,12], and solar collectors [13]. Tsai and Chein[14] investigated analytically nanofluid (water-copper and nanotube)   flow in microchannel heat sink. They was found that optimum values of aspect ratio and nanofluid did not make conversion in MCHS thermal resistance. Kalteh et al. [15] investigated the laminar nanofluid flow in rectangular microchannel heat sink both numerically and experimentally. Compared the experimental and numerical results presented that two-phase Eulerian-Eulerian method results are in better accordance with experimental results than the single-phase modeling. The reasons experimentally   study by Azizi et al.[16] reported that Nusselt numbers decreases whit rising Reynolds number and enhancement heat transfer by using nanoparticles camper to that of pure water for similar Reynolds number. Sheikholeslami et al. [17] studied effect nanoparticle on heat transfer in a cavity square containing a rectangular heated body numerically. They indicated that using nanoparticle increasing he at transfer and dimensionless entropy generation. Micro channel heat sink (MCHS) using in many applications, such as microelectronics and high energy laser. MCHS cooling is very important because heat flux in this channel higher than regular channel. Many studies analyzed the convective heat transfer characteristics of nanofluids in micro channel heat sink in recently many years ago[18-24]. Sakanova et al. [25] investigated effects of wavy channel structure on hydrodynamic behavior in microchannel heat sink. They found that increasing nanoparticles in pure water the effect of wavy wall unnoticeable. Radwan et al. [26] using nanofluid on heat transfer microchannel heat sink in low concentrated photovoltaic systems investigated numerically. They show that nanofluids is effective technique for enhance heat transfer. Tabrizi and Seyf [27] investigated laminar Al2O3-water nanofluid flow in a microchannel heat sink. They showed that increasing volume fraction of Al2O3 and nanoparticle size reducing the entropy generation. Chai et al. [28-30] studied hydrothermal characteristics of laminar flow microchannel heat sink with fan-shaped ribs. Their results presented that used the fan-shaped ribs the average friction factor 1.1-8.28 times larger than the regular microchannel, while used the offset fan-shaped ribs was 1.22-6.27 times increases. Also the microchannel with large ribs height and small ribs spacing, the frictional entropy generation rate increases and thermal entropy generation rate decreases comparing than the smooth microchannel. Magnetic fluid (ferrofluid) is a stable colloidal suspension consisting of a base liquid and magnetic nanoparticles that are coated with a surfactant layer and it can be controlled by external magnetic fields [31]. Sundar et al. [32-33] experimentally studied the heat transfer characteristic of Fe3O4 ferrofluid in a circular tube whit applied magnetic field. They detected that the heat transfer increases compared to water flow at same operating condition. Aminfar et al. [34-36] studied effect different magnetic field on ferrofluid for different channels. They showed that using the uniform and non-uniform transverse magnetic increasing heat transfer coefficient and friction factor. Also shown that non-uniform transverse magnetic enhanced heat transfer more than axial non-uniform magnetic field. In this study, the uniform and non-uniform transverse magnetic effect on heat transfer of ferrofluids flow in a microchannel heat sink with offset fan shaped by using mixture model. The effects of uniform and non-uniform transverse power magnetic fields, Reynolds number and nanoparticle diameter variation are studied in details. Governing Equations Researchers presented different models for numerical analysis in multi-phase flows [37-40]. The mixture model is one of methods for nanofluid analyses [38-41]. In this study, flow is assumed steady state, incompressible and laminar with constant thermo-physical properties. The effects of body forces and dissipation are negligible. Also, for calculate the density variations due to buoyancy force was used the Boussinesq approximation. Considering these assumptions, the dimensional equations define as: Continuity equations: (1) Momentum equations: (2) The term refers to Kelvin force; it results from the electric current flowing through the wire. In this equation, H is Magnetic field intensity vector that determined as [42]: (3) where (4) (5) I is electric intensity. The wire direction is parallel to the longitudinal channel and in the center of cross section at the (a, b). Also, M is the magnetization in Equation (2) and determined as [36]: (6) where is magnetic susceptibility of ferrofluid at 4% volume fraction for different mean diameter is present in Table 1. Table 1. magnetic susceptibility of ferrofluid for different mean diameter mean diameter magnetic susceptibility 10 0.34858668 20 2.7886935 30 9.4118388 In Equation (2), is called Lorentz force that determined as: (7) Where and are respectively effective electrical conductivity and nanofluid velocity vector, also is the induced uniform magnetic field that can be calculated by intensity of magnetic field: (8) Energy equation: (9) Volume fraction equations: (10) In Equation (10), Vm, and Vdr are the mean velocity and the drift velocity, respectively, that be defined as: (11) (12) where à Ã¢â‚¬   is the volume fraction of nanoparticles. The drift velocity depends on the slip velocity. The slip velocity defined as the velocity of base fluid (bf) with respect to velocity of nanoparticles (p) and determined as: (13) (14) The slip velocity is presented by Manninen et al. [31e]: (15) In Equation (15) f drag and r are drag coefficient and acceleration respectively, which can be calculated by: (16) (17) In Equation (16), Rep = Vmdp/veff is the Reynolds number of particles. Nanofluids Properties The physical properties of water and Fe3O4 nano-particles are shown in Table 2. The water-Fe3O4 nanofluidis assumed is homogenous that the thermos-physical mixture properties calculated for 4% volume fraction of nanoparticles. Table 2. Properties of base fluid and nanoparticles [35,40]. Properties Water Fe3O4 Density (kg/m3) 997.1 5200 Specific heat capacity (J/kgà ¢Ã‹â€ Ã¢â€ž ¢K) 4180 670 Thermal conductivity (W/mà ¢Ã‹â€ Ã¢â€ž ¢K) 0.613 6 Electrical conductivity (s/m) 5.3 25,000 Dynamic viscosity (kg/mà ¢Ã‹â€ Ã¢â€ž ¢s) 0.0009963 The physical mixture properties are calculated by means of the following equations: Density of nanofluid: (18) Specific heat capacity of the nanofluid: (19) Dynamic viscosity of nanofluid [43]: (20) Thermal expansion coefficient of nanofluid [35]: (21) Electrical conductivity [36]: . (22) Based on the Brownian motion velocity is Thermal conductivity of nanofluid [44]: (23) dp and dbf are particle diameter(nm) and molecular base fluid (0.2 nm). In Equation (23) Pr and Re are Prandtl and Reynolds number, respectively defined as: (24) (25) Also, in Equation (25) is water mean free path (17 nm) and kB is Boltzmann constant (1.3807 ÃÆ'- 10à ¢Ã‹â€ Ã¢â‚¬â„¢23 J/K). Deà ¯Ã‚ ¬Ã‚ nition of Physical Domain and numerical method Fig.1 shown the geometry of the microchannel heat sink with offset fan-shaped reentrant cavities in sidewall. The channel width and space between a pair cavity is 300 ÃŽÂ ¼m.The channel length is 2.70 mm with a thickness of 350 ÃŽÂ ¼m and the pitch distance of two longitudinal microchannels is 150 ÃŽÂ ¼m. The channel cross section heat sink has a constant width of 100 ÃŽÂ ¼m and constant depth of 200 ÃŽÂ ¼m and   radius of the fan-shaped reentrant cavity is 100 ÃŽÂ ¼m. a) b) c) Fig. 1. a) Geometry of microchannel in the present study b) Cross-sectional plane of transverse non-uniform magnetic field c) Transverse uniform magnetic field In this study, used the finite volume (FV) method to numerically solved non-linear partial differential equations. The velocity pressure coupling by SIMPLEC algorithm. The discretization of momentum and energy equations used the second order upwind scheme and the solid phase equations became discretization by first order scheme. In this study for evaluate of effect the mesh points on the precision of the results, several grid sizes have been tested for the constant heat flux at Re = 300 are given in Table 3. The 1188000 grids is adequately suitable. Table 3. Grid independent test (Re = 200,T0 = 300, 4% vol.). V/V0 T/T0 Grid 1.038 1.027 672914 1.029 1.019 889440 1.023 1.013 1188000 1.02 1.011 1591128 In order to validate this, the amount of mean temperature at the bottom of the microchannel compared by numerical result of Chai et al.[45](Fig.2). Also for comparison effect the magnetic field, the dimensionless velocity under the magnetic field compared by analytical results of Shercliff [46] that shown in Fig. 3 and can be seen a good agreement between results. Figure 2. Comparison of the results for average temperature bottom heat sink Fig.3 Comparison between numerical and analytical results for flow under magnetic field Boundary conditions The set of non-linear elliptical governing equations are solved by using the boundary conditions in the entrance of microchannel (Z = 0), u = 0; v = 0; w = v0 ; T = T0 (26) at the microchannel outlet (Z = 2.7 mm): ; u = 0; v = 0 ;P = Patm (27) In the left and right sides of microchannel outer adiabatic walls (X = 0 w): (28) In the microchannel inner walls: (29) (30) Finally, a constant heat flux condition is imposed at micro heat sink bottom wall (y = 0). Results and discussion The variations of pressure drop and Reynolds number for various transverse magnetic fields are shown in Fig. 3a. It can be seen that for a given fluid, the pressure drop increases by increasing the Reynolds number because rising the velocity inlet. As shown in Fig. 3b whit increases intensity uniform and non-uniform magnetic field in the same Reynolds number (Re=300), the pressure drop increases for non-uniform magnetic because the secondary flow near wall became larger and powerful. Also scale up particle diameter of 10nm to 30nm decreasing pressure drop (Fig. 3c). a) b) c) Fig. 3. Effects of various a) Reynolds number [H=6ÃÆ'-106, dp=30nm] b) power magnetic field gradients [Re=300, dp=30nm] c) particle diameter [H=8ÃÆ'-106, Re=300] on the pressure drop Fig. 4 presented streamlines for various magnetic fields at 0.0015à ¢Ã¢â‚¬ °Ã‚ ¤ Z à ¢Ã¢â‚¬ °Ã‚ ¤0.002. As shown in Fig.4, when magnetic field is weak the streamlines same together because the magnetic field had not enough powerful for veer stream. By increases intensity magnetic field the nanofluid flow shift to near wall and thereupon the vortex in reentrant cavities became powerful Fig.5. Fig. 4. Stream lines in same Reynolds number (Re=300) and particle diameter [dp= 30nm] for a) non-magnetic field b) non-uniform magnetic field (H=6ÃÆ'-106 A/m) c) uniform magnetic field (H=6ÃÆ'-106 A/m) Fig. 5. Stream lines in same Reynolds number (Re=300) and particle diameter [dp= 30nm] for non-uniform magnetic field a) H= 6ÃÆ'-106 A/m c) H=8ÃÆ'-106 A/m The friction factor decreases as Reynolds number increases (Fig. 6a). The magnetic field cannot overcome viscous force and affect mean velocity when intensity magnetic field is low, therefor the friction factor is almost fixed for using magnetic and non-magnetic field. Whit increases intensity magnetic field the mean velocity decreases and while the pressure drop increases (Fig. 3.b); therefore, the friction factor increases at maximum intensity field (Fig. 6b). Also scale up particle diameter the main velocity and pressure drop decreases. The uniform transverse magnetic field is depended to velocity that whit decreasing velocity the uniform transverse effect decreases on flow, so friction factor rising (Fig. 6c). a) b) c) Fig. 6. Effects of various a) Reynolds number [H=6ÃÆ'-106, dp=30nm] b) power magnetic field gradients [Re=300, dp=30nm] c) particle diameter [H=8ÃÆ'-106, Re=300] on the friction factor Figure 7 shows the variations of average temperature bottom heat sink for different condition. Whit increasing Reynolds numbers the velocity increasing too and the vortex in reentrant cavities became bigger and powerful, thus average temperature bottom heat sink decreases (Fig. 7a). Effects of various power magnetic field gradients [Re=300, dp=30nm] on average temperature bottom heat sink presented in Fig. 7b. When the intensity magnetic field is weak cannot affect average velocity because cannot overcome viscous force. By strengthening the non-uniform transverse magnetic field the average velocity became larger and growth vortex in channel, therefore average temperature bottom heat sink reduces. Particle diameter rising, the non-uniform transverse magnetic had more effect than uniform transverse magnetic and non-magnetic on average temperature bottom heat sink (Fig. 7c). Whit scale up particle diameter decreasing thermal conductivity and heat transfer for when applied uniform transv erse magnetic because it independent of particle diameter. Figure 8 presented the variations of average Nusselt number for different condition. Nusselt number enhances with Reynolds number in

The Effects of Motivation on Performance Essay examples -- Andrew and

The Effects of Motivation on Performance Findings Task 2- Write a Report on the effects of Motivation on Performance Research people’s attitude to work and factors affecting their motivation by constructing a questionnaire and conducting a small survey. You should aim to distribute your questionnaire to at least 5 people within your organisation. Gather information on what motivates individual performance and identify attitudes to work by interviewing an employee in-depth and comparing their attitudes with your own. Relate you findings to motivation theories and provide a description of the motivators appropriate for different types of individual performance. Andrew and Robertson: An Introduction to the Business Objectives Andrew and Robertson have started put life as property mangers in 1887. Managing properties on behalf of owners. Southwark Council also contracted out housing management for a trial period in the 90’s in which Andrew and Robertson’s partly participated. In the 1960’s Andrew and Robertson expanded into auctioneering. The object of this section of the business aims to sell houses at auctions 4 times a year. However 1980 prior they only had two actions a year. The business aims to make a profit for the four senor partners. The business has no obvious intentions to float on the stock market. The partnership has currently invested in a new phone system and computer network for one of its three branches. This according to an associate partner is the partnership attempting to modernise the old fashion approach to the business currently used by managers. Serves Andrew and Robertson’s serve the clients who own the properties, which they manage. The management also serve their auctioneering arm that sells properties for the clients of the property-managing arm who wish to sell their properties. Motivational Procedures Andrew and Robertson’s have no written procedures however there are a number of unwritten procedures, which are used. These procedures include: Staff/Management association (This is not like by a small minority of staff  ¼) Close quarters arrangements (Putting desks in close proximity for communication means) Appraisal Meetings (Token) Staff Management association This is the system in which higher level management work along side their employers. In the hope that the bond between the low... ...people work so hard and Physiological needs Basic needs such as food water and shelter are all met because the pay is reasonable at the firm of Andrew and Robertson’s. Food and drink is also supplied in small quantities at break times. The management sees these as incentives because in the afternoons the employees generally work harder. So therefore the reason for higher efficiently in the afternoons is the cakes and tea, which are available at lunch times and corresponds to the Physiological needs on Abraham Maslow’s Hierarchy of needs William Bridges IT Evolution William Bridges wrote that there have been many changes in the modern working environment. Including the number of jobs in an organisation deceasing or increasing during fluctuating periods of demand. He argument being the advancement of IT had increased competition and therefore the nature of management philosophy. This is truer at Andrew and Robertson’s since the number of employees aged over 40 years has dropped tremendously over the last 3 years due to the need for IT compliant staff. Since it is the partners who dictate policy their behaviour and types of behaviour towards their management policy.

Powering Indian Telecom Towers Environmental Sciences Essay

Solar energy has proven to be a dependable and economical method of powering telecommunication systems in topographic points where conventional electricity is unavailable or impractical. It provides an first-class beginning of clean, dependable power to maintain un-interrupted power supply to telecom towers. This paper contains a brief description of Indian telecom towers and photovoltaic ( PV ) cells used in telecommunication systems. Because solar energy systems are robust and cost effectual, the demand for solar power in telecommunications will go on to turn. Key Words-insolation, irradiance, photovoltaic, solar cell, solar energyIntroductionIndia is now in the 2nd largest of the Global telecom markets and is projected to get the better of China. Our state presently has about 400,000 telecom towers around the land and poised to increase to 450,000 towers over the following 2 old ages ( 2 ) . A big part of these towers is non connected to the electricity grid or does non hold entree to dependable electricity connoting they have to put in backup power systems in order to run without breaks. Diesel Generators have been the pick of telecom operators despite their high C imprint. Telecom Towers are estimation to fire 2 Billion Liters of Diesel ( around 500 million barrels ) yearly at a cost of 10000 crores. On an norm, about 260,000 is being spent yearly to carry through the Diesel demands of a individual telecom tower. These high input costs besides result in high pollution. While the authorities has been seeking to change over these towers t o renewable energy signifiers, most of the tower operators have been really slow to implement this alteration. The renewable energy ministry had asked telecom companies to cut down their dependence on conventional fuels and see options for partially powering telecom towers. While some tower Godheads are looking at tight natural gas and piped natural gas to power towers, Indus Towers, the largest with over 1 lakh towers in India, planned to put up 2,500 solar towers by terminal of this twelvemonth. Viom Networks, which operates more than 38,000 towers across India, plans to run more than one-quarter of this figure on alternate energy within the following two old ages. It plans to run 2,000 towers on solar power entirely by 2013. For the GSM Technology, it requires an norm of 6 BTS to run one tower. Each shelter has two ( 1.5 ton ) air conditioners for the cardinal care of the temperature for the shelter ‘s electronic systems. The DG set is typically 15 kVA capacity, which consu mes an norm of 3 liters of Diesel per hr [ 4 ] . Each tower requires energy from 1000 W to 3000 W ( older installing consumes more power as comparison to new one because of technological promotion ) . Each 1000 W consequences in the 22 tonnes/hr of emanation of CO2 if running on the province electricity and in instance of the gensets this figure is many times more. Assuming mean power ingestion of each tower is 1200 W so entire CO2 emanation is 105.6 lakh metric ton per hr by all these towers if we assume that all are running on province electricity. In India about 70 % telecom towers are in rural countries. Soon 40 % power demands are met by grid electricity and 60 % by Diesel generators [ 2 ] . The Diesel generators are of 10-15 KVA capacity and devour about 3 litres of Diesel per hr and bring forth 2.63 kilogram of CO2 per litre. For every kWh of grid electricity consumed, 0.84 Kg of CO2 is emitted. Entire CO2 emanation is around 5 million tones of CO2 due to diesel ingestion and around 8 million dozenss due to power grid per an num. The move from Diesel to solar and other alternate beginnings of energy will ensue in a decrease of 5 million dozenss of CO2 emanations every bit good as a nest eggs of immense sum in operating disbursals for telecom tower companies. Move to renewable energy beginnings can bring forth 1000000s of C credits that could countervail the opex on their towers. Therefore by replacing diesel generators with solar panels in cell phone towers, more than 5 million dozenss of C emanations could be prevented from come ining the ambiance and cut down the opex of telecom towers. India has approximately 500 million nomadic phone endorsers, more than even the population of any state except China India is expected to hold one billion mobile phone endorsers by 2015 which would intend about 250,000 more Mobile towers which, in bend, would duplicate the C emanations. Even if the solar panels supply a portion of the entire power required, it would still salvage significant sums of money, fuel and C e manations.Electricity Generation Through Solar CellsIn India the one-year solar radiation is about 5 kWh/ sq thousand per twenty-four hours with about 1500-2000 sun-shine hours per twelvemonth. Solar radiations represent the Earth ‘s most abundant energy beginning. The perennial beginning of solar energy provides limitless supply, has no negative impact on the environment. The solar photovoltaic ( PV ) modules convert solar radiation from the Sun into electrical energy in the signifier of direct current ( DC ) . Converting solar energy into electricity is the reply to the mounting power jobs in telecom towers peculiarly in the rural countries. PV or solar cells are semiconductor devices that convert sunlight into direct current electricity ( Fig.1 ) . When light photons of sufficient energy work stoppage a solar cell, they knock negatrons free in the silicon crystal construction, coercing them through an external circuit and so returning them to the other side of the solar cel l to get down the procedure all over once more. Fig. 1. ( a ) photovoltaic consequence ( B ) how a PV cell plants ( degree Celsius ) a crystalline Si panel The electromotive force end product from a individual crystalline solar cell is about 0.5 V with an amperage end product that is straight relative to the cell ‘s surface country ( about 7 amperes for a 6-inch-square multi crystalline solar cell ) . Typically, 30 to 36 cells are wired in series ( + to – ) in each solar faculty. This produces a solar faculty with a 12-volt nominal end product ( ~17 Vs at peak power ) that can so be wired in series and/or parallel with other solar faculties to organize a complete solar array. Solar cells used in telecom towers are shown in Fig 2. Solar cell is cosmopolitan and will work virtually anyplace ; nevertheless, some locations are evidently more suited than others. Irradiance is a step of the Sun ‘s power available at the Earth ‘s surface, with power peaking at about 1,000 Wattss per square metre ( W/m2 ) . With typical crystalline solar cell efficiencies about 14 to 16 per centum, approximately 140 to 160 Wattss can be generated per square metre of solar cells placed in full Sun. Insolation, which is a step of the available energy from the Sun, is expressed in footings of â€Å" full Sun hours † ( i.e. , 4 full Sun hours = 4 hours of sunshine at an irradiance degree of 1,000 W/m2 ) [ 1 ] . Fig.2 Solar cells used in telecom tower for United Nations interrupted power supply.Tele DensityTelephone introduced in India in 1882. The entire figure of telephones in the state stands at 885.99 million, while the overall tele-density has increased to 73.97 % and the entire Numberss of nomadic phone endorsers have reached 851.70 million as of June 2011. Himachal Pradesh has become the first province in India to accomplish 100 per cent tele-density. The province has about seven million nomadic clients [ 5 ] . The province population is 6.8 million as per the Census 2011 much lower than the nomadic subscriber population of seven million. While the urban tele denseness reached 150.67 per cent, the rural tele denseness reached 32.11per cent. Experts have pointed out that the grounds for this rapid growing are lowest call rates, big market base due to bigger population, well ample untapped market and robust economic growing of the state. In add-on factors like rapid technological accept ance, better service criterions, advanced merchandise offerings and competitory pricing amongst the service suppliers has besides contributed in a major manner to increase the tele-density of the state.Energy Management in Telecom TowersA Telecom tower enables telecom operators to supply web connexion to mobile users. Fig. 3 Standard Telecom System Telecom being an indispensable service requires the web to be ever available. In order to accomplish this, the tower substructure that has 2 operators uses 6-8 kilowatt ( avg. ) of electricity per hr ( Fig.3 ) . Energy demands of a telecom tower in India are presently met through: Electricity Mains Diesel Generator and UPS / Battery RacksDiesel Consumption in Telecom Towers and Environmental PollutionThe telecom operator spends 3 billion ( USD 67.42 million ) every month towards running Diesel generators in distant locations where grid base power is limited. This translates to an operational energy disbursal of around 65 billion yearly to run web towers, particularly in off-grid locations ( 4 ) . Since, Electricity supply is fickle and is non available through out the twenty-four hours in many parts, Diesel Generators ( DG ) are used to power the telecom web, as a dorsum up for power supply. DG ‘s are operational for 15-20 hours ( avg. ) in rural countries and 3- 7 hours in urban countries ( Table 1 ) seting a emphasis on the environment by manner of C emanations and noise pollution One liter of Diesel emits 2.63 kilogram of CO2 emanations. Hence telecom webs contribute to carbon emanations and planetary heating. Table 1 Power Availability at Tower SitesGrid Power Availability Cell Sites10 % : & gt ; 20 hour Chiefly metro metropoliss of Mumbai, Kolkota, Chennai, some metropoliss of Gujarat, State of Chattisgarh, some metropoliss of Punjab 20 % : 16-20 hour Covers most other major metropoliss and towns in the remainder of the state 30 % : 12-16 hour All semi-urban and little urban towns in all provinces 25 % : 8-12 hour Mostly rural countries 15 % : & lt ; 8 hour Mostly parts of Bihar and some towns of Assam, NE provinces, UP and J & A ; K The Power Problem A speedy analysis of telecom web runing costs indicates power and fuel are the primary operating costs, consisting over 30 % of entire operating cost. This is because grid power ( Electricity Board or EB power ) is extremely undependable and in a batch of instances, non available in rural countries. BTS sites require changeless and uninterrupted power for the safe operation of the web. As a consequence, BTS sites have utilized onsite Diesel generators to either supply backup or primary power in the absence of EB power. Uninterrupted operation is achieved through a battery bank. The typical constellation of DG sets is 10-15 KVA with a fuel burn rate of 2-3 liters per hr ( depending on full or half load operations ) . Assuming seven hours of DG operations in urban countries and 20 hours in rural countries, estimated use of Diesel fuel is 2-4 billion liters per twelvemonth across the 400,000 towers in India. Fuel demand is increasing with each new tower. India, with its first-class irra diance, has the chance to work Photovoltaic ( PV ) solar power to run into this challenge of onsite power coevals. Coupled with a battery backup, PV systems are a feasible and exciting option to cut down the power cost and entire operating outgo ( OPEX ) , thereby supplying a sustainable and dependable strategic solution to the fuel job. The operating cost of Diesel and solar PV system is shown in Table-2 which shows that solar PV system is economical ( 14.08/kWh ) than Diesel DG sets ( 16.19/kWh ) and besides eco friendly and can market their C recognition to cut down farther the opex of the telecom tower. Table 2. Comparative analysis of solar PV and diesel generators ( DG ) uses in telecom tower.Strictly DG setsStrictly PV systemAnnual ingestion of 15 kVA DG sets @ 3 litres/h, liters 26280 Assumed capacity, Wp 15000 4 % shut down period i.e.for 96 % operation, liters 25229 Annual sunshine hours 1650 kWh produce @ 3.5 kWh/litre 88301.5 10 twelvemonth output, kWp 247500 Diesel cost @ 42/litre, 1059618 Capital investing @ 200/Wp, 30,00,000 Cost of machine etc, 300000 Operating cost, ( including depreciation, involvement, care ) , /10 old ages 49,80,000 Operating cost ( including depreciation, involvement, housing/rent, care ) , /year 1429918 Operating cost/kWh, 16.19 Operating cost/kWh, 20.12 After 30 % subsidy 14.08 Telecommunication Companies and Their Role ECIndia has the fastest turning telecom web in the universe with its high population and development potency. India ‘s public sector telecom company BSNL ( 11.41 % ) is the seventh largest telecom company in universe. The entry of new participants into the telecom industry has made competition intense, in peculiar over the last four old ages. The dominant participants in the market presently include Bharti-Airtel ( 20.09 per cent of the Indian market ) , Reliance Communications ( 16.70 % ) , Vodafone ( 16.54 % ) , Tata Tele Services ( 11.08 % ) , Idea ( 10.97 % ) and Aircel ( 6.76 % ) ( Table 3 ) . Table 3. Share of telecom companies in Indian market and stairss taken to utilize renewables Companies Market portion, % Stairss taken for usage Renewable energy in teletowers Bharati Airtel 20.09 Targeted for solarizing 2000 towers by 2010-11. No latest information on accomplishment. Reliance Communication 16.70 Stairss taken to utilize renewable to cut down opex by 50-60 % Vodafone 16.54 23 % of its planetary operation by renewables BSNL 11.41 Taken pilot undertakings under Jawharlal Nehru Solar Mission for solarizing towers. Tata Teleservices Ltd 11.08 Deployed 31 cell sites powered by solar power and fuel cells. Idea Cellular 10.97 Solar-DG loanblend in some nomadic towers Aircel 6.76 No information available Stel 0.34 Cringle 0.39 Eti Salat 0.08 HFCL 0.18 Uninor 2.73 Videcon 0.83 MTNL 0.69 Siestema 1.21 Beginning: Telephone Regulatory Authority of India ( as on 28th Feb, 2011 ) As per the directives of Ministry of New and Renewable Energy, some companies have taken inaugural stairss to utilize renewable energy beginnings to power their telecom towers. Some major are: Bharti Infratel has set a mark of deploying 2000 renewable energy sites by the fiscal twelvemonth 2010-11. The undertaking is besides expected to ensue in an estimated decrease of 58,170 metric tons of CO2 emanations per twelvemonth. BSNL has taken up pilot undertakings for 10 kilowatts solar workss at 14 sites and Wind power undertaking at 6 USO funded sites in Rajasthan, Gujarat, Tamil Nadu, Karnataka and Maharashtra. Indus Towers, the largest with over 1 lakh towers in India, will put up 2,500 solar towers by September this twelvemonth. Viom Networks, which operates more than 38,000 towers across India, plans to run more than one-quarter of this figure on alternate energy within the following two old ages. It plans to run 2,000 towers on solar power entirely by 2013. There are around 5,60,276 Base Transceiver Stations ( BTS ) in the state. It may be noted that BTS is different from towers as one tower may hold more than one BTS. In India the tower companies portion the tower sites with all telecom operators. While the tower is erected by the tower substructure companies, the BTS is installed by the telecom operators. A nomadic tower is an aerial where electronic communications equipment are placed on a wireless mast or tower to make a cell in a cellular web. A nomadic tower is composed of a tower or other elevated construction for mounting aerial and one or more sets of transmitter/receivers transceivers, digital signal processors, control electronics, a GPS receiving system, regular and backup electrical power beginnings, and sheltering. Circle wise interruption up of BTS is given below [ 3 ] . Metro DelhiA A A A A A A A A A A A A A A A A A A A A A A A A A 20,715 MumbaiA A A A A A A A A A A A A A A A A A A A A A 21,038 KolkottaA A A A A A A A A A A A A A A A A A A A A 14,018 TotalA A A A A A A A A A A A A A A A A A A A A A A A A A 55,771 A Circles MaharashtraA A A A A A A A A A A A A A A 42,998 GujaratA A A A A A A A A A A A A A A A A A A A A A A 31,852 Andhra PradeshA A A A A A A A A A A 43,661 KarnatakaA A A A A A A A A A A A A A A A A A 39,093 Tamil NaduA A A A A A A A A A A A A A A A 52,075 TotalA A A A A A A A A A A A A A A A A A A A A A A 2,09,679 Fig 4. A roof top Mobile tower in Bhubaneswar utilizing intercrossed grid-DGB Circles KeralaA A A A A A A A A A A A A A A A A A A A A A A A 27.156 Fig.3 A BTS system PunjabA A A A A A A A A A A A A A A A A A A A A A A A 19,575 HaryanaA A A A A A A A A A A A A A A A A A A A A 13,883 UPA A A A A A A A A A A A A A A A A A A A A A A A A A A A A 68,487 RajasthanA A A A A A A A A A A A A A A A A A A 28,694 Madhya PradeshA A A A A A A A A A A 31,665 West BengalA A A A A A A A A A A A A A A 24,532 TotalA A A A A A A A A A A A A A A A A A A A A A A 2,13,992 C Circles Himachal PradeshA A A A A A A A A 5,425 BiharA A A A A A A A A A A A A A A A A A A A A A A A A A 35,086 OrissaA A A A A A A A A A A A A A A A A A A A A A A A 18,095 AssamA A A A A A A A A A A A A A A A A A A A A A A A A 9,610 North EastA A A A A A A A A A A A A A A A A A A 5,490 Jammu & A ; KashmirA A A A A A A A 7,128 TotalA A A A A A A A A A A A A A A A A A A A A A A A A A 80,834 Grand TotalA A A A A A A A A A A A A A 560,276DecisionTo cut down CO2 emanation and planetary heating due to telecom towers, Govt. should do it compulsory to telecom companies to utilize renewable energy.Govt. should halt subsidy on Diesel for telecom companies. More inducements should be given to those who use renewable energy for their towers.

Fossil Fuels – discovery, utilisation and future

As industry developed and increased, as did the need for reliable and efficient fuels to power the new machinery developed. It did not take long before fossil fuels were discovered, with their innate ability to provide high amounts of energy at seemingly low costs. Fossil fuels are found deposited in rock formations. They were formed between 350 million and 50 million years ago, and so, although are technically renewable, it would take this long to remake them, which does not really help us today, it is due to the fact we need this long to make them that they are considered nonrenewable, and therefore will at some point run out. The processes by which they formed are not totally understood, other than that sediments buried decayed remains of ancient plants and/or animals. This is then effectively baked over millions of years under conditions of very high temperature and pressure, creating coal, oil, and natural gas, which consist of roughly 90% carbon Fossil fuels are used widely in all forms of industry, in fact, coal, petroleum and gas provides over 90% of the energy used in most industrialized countries, compared with just 9% which hydroelectricity and nuclear power provide together. You can read also Waves When looking at the properties of a good fuel, it is easy to see why fossil fuels are used: * A fuel should react with an oxidiser to release large amounts of energy – carbon based fuels release over 30000 kJ per kilogram * A fuel must be oxidised fairly easily, ignite quickly and sustain burning without further intervention – gaseous or easily vaporized fuels (such as oil) usually perform well here as the mix easily and continuously with oxygen which speeds up the reaction. Coal is often crushed to form small powders to make it ignite easier, however it is evident from steam the reliability of steam trains that carbon is easily burnt. * A fuel should be readily available, in large quantities and at a reasonable price – initially this could be said to be true about fossil fuels, but now, as people become more aware of their cons, and of other fuels' pros, they are becoming more expensive and less available. Still, the price of oil is so heavily depended upon by the economy, that even the slight fluctuation in price can cause a country to go to war or a government to fall. * A fuel should not burn to give products that are difficult to dispose of, unpleasant or harmful – fossil fuels definitely do not fall under this category, but the only fuel that does fall under this category is hydrogen. * A fuel should be convenient to store and transport safely and with out loss – fossil fuels are the only type of fuel that people are currently comfortable with storing, hydrogen and methane are so flammable that people get nervous about using them for cars, and until a safe way of storing them is developed, fossil fuels will have to continue to be used You may then wonder what the problem with fossil fuels is as they are obviously good at their job. What we must consider is the fact that they are non-renewable, and that we are consuming them at an incredible rate. It is predicted that most of the Earth's oil sources will be depleted over the century. Also, fossil fuels are used in many important chemical industries, such as making plastics, medicines, and solvents, and by burning them, we are decreasing our the feedstock for these vital products. Fossil fuels such as oil are made into these products through a series of different processes. First the oil is fractionally distilled then the different sections join together to make polymers. These synthetic plastics and solvents are used largely in everyday life, such as polystyrene cups and PVC plastic. Secondly, the burning of carbon based fuels produces large amounts of carbon dioxide that is one of the main contributors to the â€Å"greenhouse effect†. There are such drastically high levels of carbon dioxide in the air that the only real solution would be to ban all use of fossil fuels, but countries have become so dependant upon them that is not feasible. Thirdly, spillages of fossil fuels cause serious damages to local environments. When an oil tanker crashes, immense amounts of sea life and birds die, and the effects are disastrous. Fourthly, inefficient burning of fossil fuels results in the production of carbon monoxide, which is a very harmful and poisonous gas. Inhalation of this gas is likely to cause death as it interferes with the transport of oxygen in the blood stream. Fifthly, combustion of fossil fuels also produces gases such as nitrogen oxides, which cause acid rain. In particular we can look at oil. Numerous countries' entire economies now rely on the price of oil, as their entire wealth is in the drilling, extracting, and trading in it. This is cause for great concern as oil is non-renewable, and we are consuming it so quickly, it will inevitably run out, and counties will no longer be able to rely on it. We have seen in the past that countries' entire economies' have collapsed due to minor fluctuations in the oil market, therefore total collapse of the market would be devastating for many of the world's major and influential countries. Also, there would be immense amounts of job losses that would inevitably affect the society; this can be seen by looking at the destruction caused when the coalmines closed. There are few ways which can be seen to overcome this imminent problem, however, one, most likely solution would be to investigate alternatives to fossil fuels, but all of the possible alternatives have their advantages and disadvantages which must be taken into account before making any changes. * Biofuels (plants can be grown specifically for fuel or the production of fuel, such as wood or sugar cane. Biogas and biomass created by the growing and decaying of plants already produce usable fuel so this could easily be exploited to create a fuel source.) Advantages – renewable, reduces waste, simple technology. Disadvantages – not a large enough supply to totally replace fossil fuels * Methanol CH3OH (this is a simple alcohol which can be made from methane.) Advantages – burns cleanly and completely Disadvantages – more toxic than ethanol, provides less energy per litre than petrol, can cause corrosion of car engines. * Nuclear fission (energy is released when the nuclei of atoms of isotopes of uranium U-35 are split. The energy created can be used to heat water to turn steam turbines.) Advantages – no carbon, sulphur, or nitrogen oxides produces. Disadvantages – radioactive waste, safety systems needed are very expensive. * Nuclear fusion (energy is released when deuterium and tritium â€Å"fuse† to create helium) Advantages – potentially almost limitless as an energy supply as the reactants come from water. Disadvantages – very costly, cannot currently be produced at economic rates. * Moving air (wind turns windmills and wind turbines. Lots of research is already being carried out and soon may provide 10% of the UK's energy) Advantages – renewable, pollution and waste free, can be used in locality to where the energy is needed. Disadvantages – high initial expense, not reliable in calm weather, noise and visual environmental impact * Moving water (Hydroelectricity – water stored behind dams can be released through turbines to generate electricity. Waves – The motion of waves is used to create oscillating motion. Tides – incoming tides in river estuaries fill up large water stores behind barrages, which is then released through turbines.) Advantages – renewable, predictable, pollution and waste free, large scale. Disadvantages – costly to install, environmental impact. * Sunlight (Solar panels – collect solar heat and are used to heat water. Photovoltaic cells – convert light into electricity). Advantages – renewable, pollution and waste free. Disadvantages – Not good for places of low sunlight levels, high initial costs, not very practical for large-scale use. * Geothermal energy (heat from rocks under the Earth's surface can be used to heat water which can, in turn, be used to heat houses). Advantages – practically unlimited. Disadvantages – not widely available, large initial costs * Hydrogen (extracted from water by electrolysis, many things are capable of running on hydrogen). Advantages – no pollution. Disadvantages – people are nervous about using such a dangerously explosive gas, difficult to store and transport. If some of these possibilities were researched further, they could replace fossil fuels and help many of the previously discussed issues.

Free Essays on Effect Of Heredity And Environment

Effects of Heredity and Environment on individual Differences Most psychologists acknowledge that both heredity and environment are influential; the argument is over which factor is predominant The nature-nurture issue first became a controversy in the 1920's and the 1930's. Some psychologists felt that heredity was the primary, if not the sole, factor in the development of an individual. Others felt environment was the critical determining factor. As we saw in Unit One, this controversy is still unresolved. Still, most psychologists agree that some degree of interaction between heredity (nature) and environment (nurture) determines both physical and psychological development. In this module we will consider the relation of both factors to intelligence and behavior disorder. As you read the text, consider the following questions. Has heredity or environment made the greater contribution to your development? Are there any upper or lower limits of intellectual achievement? What research methods are used in heredity-environment studies? The interaction between heredity and environment can be studied by investigating families and persons who are related in various ways. Hereditary similarity is relatively well understood. A parent and child, for example, have 50% of their genes in common, but among siblings this may vary from 0 to 100% due to the random distribution of chromosomes. Identical twins have the same heredity; 100% of their chromosomes are alike. Environmental differences cannot be stated in such concrete terms. No two persons experience an identical environment. Very similar environments are usually experienced by same-sexed twins, whether identical or fraternal. Different-sexed twins, siblings, and parents all experience somewhat different environments, although these environments may be superficially similar. Occasionally, identical twins are reared apart. Then we have two people with identical here... Free Essays on Effect Of Heredity And Environment Free Essays on Effect Of Heredity And Environment Effects of Heredity and Environment on individual Differences Most psychologists acknowledge that both heredity and environment are influential; the argument is over which factor is predominant The nature-nurture issue first became a controversy in the 1920's and the 1930's. Some psychologists felt that heredity was the primary, if not the sole, factor in the development of an individual. Others felt environment was the critical determining factor. As we saw in Unit One, this controversy is still unresolved. Still, most psychologists agree that some degree of interaction between heredity (nature) and environment (nurture) determines both physical and psychological development. In this module we will consider the relation of both factors to intelligence and behavior disorder. As you read the text, consider the following questions. Has heredity or environment made the greater contribution to your development? Are there any upper or lower limits of intellectual achievement? What research methods are used in heredity-environment studies? The interaction between heredity and environment can be studied by investigating families and persons who are related in various ways. Hereditary similarity is relatively well understood. A parent and child, for example, have 50% of their genes in common, but among siblings this may vary from 0 to 100% due to the random distribution of chromosomes. Identical twins have the same heredity; 100% of their chromosomes are alike. Environmental differences cannot be stated in such concrete terms. No two persons experience an identical environment. Very similar environments are usually experienced by same-sexed twins, whether identical or fraternal. Different-sexed twins, siblings, and parents all experience somewhat different environments, although these environments may be superficially similar. Occasionally, identical twins are reared apart. Then we have two people with identical here...