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DISC BRAKE IN DIFFERENT VEHICLE
INTRODUCTIONA disc brake is a type of brake that uses the calipers to squeeze pairs of pads against a disc or "rotor"This action slows the rotation of a shaft, such as a vehicle axle, either to reduce its rotational speed or to hold it stationary. The energy of motion is converted into waste heat which must be dispersed.DESIGN Development of disc-type brakes began in England in the 1890. In 1902 designed brakes that looked and operated in a similar way to a modern disc-brake system even though the disc was thin and a cable activated the brake pad. Compared to drum brakes, disc brakes offer better stopping performance because the disc is more readily cooled. As a consequence discs are less prone to the brake fade caused when brake components overheat. Disc brakes also recover more quickly from immersion (wet brakes are less effective than dry ones). The disc is usually made of cast iron, but may in some cases be made of composites such as reinforced carbon–carbon or ceramic matrix composites. This is connected to the wheel and/or the axle. BRAKE DISC The brake disc (or rotor) is the rotating part of a wheel's disc brake assembly, against which the brake pads are applied. The material is typically gray iron Discs for motorcycles, bicycles, and many cars often have holes or slots cut through the disc. This is done for better heat dissipation, to aid surface-water dispersal, to reduce noise, to reduce mass, or for marketing cosmetics. Slotted discs have shallow channels machined into the disc to aid in removing dust and gas. Slotting is the preferred method in most racing environments to remove gas and water and to deglaze brake pads. Some discs are both drilled and slotted. Slotted discs are generally not used on standard vehicles because they quickly wear down brake pads; however, this removal of material is beneficial to race vehicles since it keeps the pads soft and avoids vitrification of their surfaces. On the road, drilled or slotted discs still have a positive effect in wet conditions because the holes or slots prevent a film of water building up between the disc and the pads. MOTORCYCLE AND SCOOTERS Unlike car disc brakes that are buried within the wheel, bike disc brakes are in the airstream and have optimum cooling. Although cast iron discs have a porous surface which give superior braking performance, such discs rust in the rain and become unsightly. Accordingly, motorcycle discs are usually stainless steel, drilled, slotted or wavy to disperse rain water. Modern motorcycle discs tend to have a floating design whereby the disc "floats" on bobbins and can move slightly, allowing better disc centering with a fixed caliper. A floating disc also avoids disc warping and reduces heat transfer to the wheel hub. Calipers have evolved from simple single-piston units to two-, four- and even six-piston items.[31] Compared to cars, motorcycles have a higher center of mass:wheelbase ratio, so they experience more weight transfer when braking. Front brakes absorb most of the braking forces, while the rear brake serves mainly to balance the motorcycle during braking. Modern sport bikes typically have twin large front discs, with a much smaller single rear disc. Bikes that are particularly fast or heavy may have vented discs.One problem with motorcycle disc brakes is that when a bike gets into a violent tank-slapper (high speed oscillation of the front wheel) the brake pads in the calipers are forced away from the discs, so when the rider applies the brake lever the caliper pistons push the pads towards the discs without actually making contact. The rider immediately brakes harder, which pushes the pads onto the disc much more aggressively than during normal braking. For example, The Michele Pirro incident at Mugello,Italy 1 June 2018. At least one manufacturer has developed a system to counter the pads being forced away.BICYCLEMountain bike disc brakes may range from simple, mechanical (cable) systems, to expensive and powerful, multi-piston hydraulic disc systems, commonly used on downhill racing bikes. Improved technology has seen the creation of vented discs for use on mountain bikes, similar to those on cars, introduced to help avoid heat fade on fast alpine descents. Although less common, discs are also used on road bicycles for all-weather cycling with predictable braking, although drums are sometimes preferred as harder to damage in crowded parking, where discs are sometimes bent. Most bicycle brake discs are made of steel. Stainless steel is preferred due to its anti-rust properties.[33] Discs are thin, often about 2 mm. Some use a two-piece floating disc style, others use a floating caliper, others use pads that float in the caliper, and some use one moving pad that makes the caliper slide on its mounts, pulling the other pad into contact with the discHEAVY VEHICLES Disc brakes are increasingly used on very large and heavy road vehicles, where previously large drum brakes were nearly universal. One reason is that the disc's lack of self-assist makes brake force much more predictable, so peak brake force can be raised without more risk of braking-induced steering or jackknife on articulated vehicles. Another is disc brakes fade less when hot, and in a heavy vehicle air and rolling drag and engine braking are small parts of total braking force, so brakes are used harder than on lighter vehicles, and drum brake fade can occur in a single stop. For these reasons, a heavy truck with disc brakes can stop in about 120% the distance of a passenger car, but with drums stopping takes about 150% the distance. In Europe, stopping distance regulations essentially require disc brakes for heavy vehicles. In the U.S., drums are allowed and are typically preferred for their lower purchase price, despite higher total lifetime cost and more frequent service intervals.RAIL AND AIRCRAFTStill-larger discs are used for railroad cars, trams and some airplanes. Passenger rail cars and light rail vehicles often use disc brakes outboard of the wheels, which helps ensure a free flow of cooling air. Some modern passenger rail cars, such as the Amfleet II cars, use inboard disc brakes. This reduces wear from debris, and provides protection from rain and snow, which would make the discs slippery and unreliable. However, there is still plenty of cooling for reliable operation. Some airplanes have the brake mounted with very little cooling, and the brake gets quite hot in a stop. This is acceptable as there is sufficient time for cooling, where the maximum braking energy is very predictable. Should the braking energy exceed the maximum.AUTOMOTIVE DISCFor automotive use, disc brake discs are commonly made of grey iron. The SAE maintains a specification for the manufacture of grey iron for various applications. For normal car and light-truck applications, SAE specification J431 G3000 (superseded to G10) dictates the correct range of hardness, chemical composition, tensile strength, and other properties necessary for the intended use. Some racing cars and airplanes use brakes with carbon fiber discs and carbon fiber pads to reduce weight. Wear rates tend to be high, and braking may be poor or grabby until the brake is hot.BRAKE PADS Brake pads are designed for high friction with brake pad material embedded in the disc in the process of bedding while wearing evenly. Friction can be divided into two parts. They are: adhesive and abrasive. Depending on the properties of the material of both the pad and the disc and the configuration and the usage, pad and disc wear rates will vary considerably. The properties that determine material wear involve trade-offs between performance and longevity. The brake pads must usually be replaced regularly (depending on pad material, and drivestyle), and some are equipped with a mechanism that alerts drivers that replacement is needed, such as a thin piece of soft metal that rubs against the disc when the pads are too thin causing the brakes to squeal, a soft metal tab embedded in the pad material that closes an electric circuit and lights a warning light when the brake pad gets thin, or an electronic sensor. Generally road-going vehicles have two brake pads per caliper, while up to six are installed on each racing caliper, with varying frictional properties in a staggered pattern for optimum performance.Early brake pads (and linings) contained asbestos, producing dust which should not be inhaled. Although newer pads can be made of ceramics, Kevlar, and other plastics, inhalation of brake dust should still be avoided regardless of material.RUSTINGThe discs are commonly made from cast iron and a certain amount of surface rust is normal. The disc contact area for the brake pads will be kept clean by regular use, but a vehicle that is stored for an extended period can develop significant rust in the contact area that may reduce braking power for a time until the rusted layer is worn off again. Rusting can also lead to disc warping when brakes are re-activated after storage because of differential heating between unrusted areas left covered by pads and rust around the majority of the disc area surface. Over time, vented brake discs may develop severe rust corrosion inside the ventilation slots, compromising the strength of the structure and needing replacement.APPLICATION Disc brakes are familiar from automotive applications where they are used extensively for car and motorcycle wheels. These typically consist of a cast iron disc, bolted to the wheel hub. This is sandwiched between two pads actuated by pistons supported in a caliper mounted on the stub shaft.When the brake pedal is pressed, hydraulically pressurized fluid is forced into the cylinders, pushing the opposing pistons and brake pads into frictional contact with the disc. The advantages of this form of braking are steady braking, easy ventilation, balancing thrust loads, and design simplicity. There is no self-energizing action, so the braking action is proportional to the applied force. The use of a discrete pad allows the disc to cool as it rotates, enabling heat transfer between the cooler disc and the hot brake pad. As the pads on either side of the disc are pushed to the disc with equal forces, the net thrust load on the disc cancels.
KRISHNENDU GHOSH
CORONAVIRUS(COVID-19)
What is a coronavirus?Coronaviruses are a large family of viruses which may cause illness in animals or humans. In humans, several coronaviruses are known to cause respiratory infections ranging from the common cold to more severe diseases such as Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS). The most recently discovered coronavirus causes coronavirus disease COVID-19.What is COVID-19?COVID-19 is the infectious disease caused by the most recently discovered coronavirus. This new virus and disease were unknown before the outbreak began in Wuhan, China, in December 2019. COVID-19 is now a pandemic affecting many countries globally.What are the symptoms of COVID-19?The most common symptoms of COVID-19 are fever, dry cough, and tiredness. Other symptoms that are less common and may affect some patients include aches and pains, nasal congestion, headache, conjunctivitis, sore throat, diarrhea, loss of taste or smell or a rash on skin or discoloration of fingers or toes. These symptoms are usually mild and begin gradually. Some people become infected but only have very mild symptoms.Most people (about 80%) recover from the disease without needing hospital treatment. Around 1 out of every 5 people who gets COVID-19 becomes seriously ill and develops difficulty breathing. Older people, and those with underlying medical problems like high blood pressure, heart and lung problems, diabetes, or cancer, are at higher risk of developing serious illnessWhat should I do if I have COVID-19 symptoms and when should I seek medical care?If you have minor symptoms, such as a slight cough or a mild fever, there is generally no need to seek medical care. Stay at home, self-isolate and monitor your symptoms. Follow national guidance on self-isolation.However, if you live in an area with malaria or dengue fever it is important that you do not ignore symptoms of fever. Seek medical help. When you attend the health facility wear a mask if possible, keep at least 1 metre distance from other people and do not touch surfaces with your hands. If it is a child who is sick help the child stick to this advice.How does COVID-19 spread?People can catch COVID-19 from others who have the virus. The disease spreads primarily from person to person through small droplets from the nose or mouth, which are expelled when a person with COVID-19 coughs, sneezes, or speaks. These droplets are relatively heavy, do not travel far and quickly sink to the ground. People can catch COVID-19 if they breathe in these droplets from a person infected with the virus. This is why it is important to stay at least 1 meter) away from others. These droplets can land on objects and surfaces around the person such as tables, doorknobs and handrails. People can become infected by touching these objects or surfaces, then touching their eyes, nose or mouth. This is why it is important to wash your hands regularly with soap and water or clean with alcohol-based hand rub.WHO is assessing ongoing research on the ways that COVID-19 is spread and will continue to share updated findings. How can we protect others and ourselves if we don't know who is infected?Practicing hand and respiratory hygiene is important at ALL times and is the best way to protect others and yourself.When possible maintain at least a 1 meter distance between yourself and others. This is especially important if you are standing by someone who is coughing or sneezing. Since some infected persons may not yet be exhibiting symptoms or their symptoms may be mild, maintaining a physical distance with everyone is a good idea if you are in an area where COVID-19 is circulating.
History of Cryogenic Engine
Hello readers!! Welcome to another article on rocket technology. In the last article, I discussed the Liquid Propulsion System. In this article, I will focus on a special type of liquid propulsion engine, Cryogenic Engine.You may have heard of this term before. If not, don’t worry, we will keep our discussion very simple and knowledgeable as well. But, if you are new to this topic, please go through the previous article for a better understanding.What does the term Cryogenic mean?The term “Cryogenics” is associated with the branch of physics that deals with the effects and behavior of materials in very low temperatures.Here a question may be raised, is there any bordering temperature for Cryogenics??..... No, there is no specific bordering temperature for cryogenics.Scientists assume a gas to be cryogenic if it can be liquified at or below -150°C.IAs an example, Hydrogen is a cryogenic fluid and it can be liquified at -253°C.What is a cryogenic rocket engine?A Cryogenic Rocket Engine is an engine that uses cryogenic fluid as fuel and oxidizer. Both the fuel and oxidizer are liquified gases and they are stored and handled at very low temperatures in the cryogenic rocket engine.So, maintaining the temperature that is far less than 0°C and execute the operations at that temperature is a challenge for rocket engineering. This challenge leads to a much-complicated structure of a cryogenic rocket engine than the structure of a usual liquid propulsion engine or a solid propulsion motor. Importance of Cryogenic Rocket Engine:In the choice of fuel and oxidizer, Oxygen is the simplest oxidizer and Hydrogen is the simplest fuel. So, we can consider hydrogen-oxygen combination is one of the most preferable propellants for rocket engines as they release a high amount of energy when combusted and generate high thrust to propel a rocket.But the problem with the hydrogen-oxygen combination is both of them are gas at normal temperature. It is possible to store them as pressurized gas, but this would require large and heavy storage tanks, which would make spaceflight almost impossible.So, these gasses are cooled to sufficiently low temperature and liquified and then stored in tanks. They are handled at that temperature and used as the propellant in the Cryogenic engine.Various fuel-oxidizer combination has been used as propellent of the cryogenic engine. But generally, the hydrogen-oxygen combination is used as they are easily and cheaply available.History of Cryogenic Engine:he world's first cryogenic engine, RL10, was developed in 1962 in the United States of America by Marshall Space Flight Centre (NASA) and its first successful flight took place on 27th November 1963. It was mainly developed for Lunex Lunar Lander. On the first flight, it was used in the upper stage of Atlas Launch Vehicle.This RL-10 engine was one of the most important weapons of NASA’s space exploration.On 26th February 1966, another cryogenic engine, J-2, developed by NASA, completed its first flight successfully. This engine is considered as one of the main factors of the success of SATURN-V Launch Vehicle in many different missions including the Appolo-11 mission ...IMPORTANT NOTE:-(A) In GSLV Mk-I, Russian cryogenic engine, KVD-1 was used in the third stage of the launch vehicle. In GSLV Mk-II, KVD-1 was replaced by India’s CE-7.5 engine. In GSLV MK-III, it is further replaced by India’s CE-20 engine.(B) In India, Liquid Propulsion Systems Centre (ISRO) developed the first Indian Cryogenic Engine, CE-7.5 under Cryogenic Upper Stage Project (CUSP).(C) Unfortunately, the first flight of the CE-7.5 engine ended with a failure in 2010. Later in 2014, this engine completed its first flight successfully.(D) In 2017, Liquid Propulsion Systems Centre (ISRO) developed another cryogenic engine, CE-20. It completed the first successful flight on 5th June 2017. (THE END )
Propulsion System : The Introduction(UNIT-I)
Hello Reader!! Welcome to another article on Rocket Science. In this article, I will discuss a very important topic, or you may consider as the most important topic, named Propulsion System. This is one of the most complicated topics of rocket science. Don't worry, I will keep it simple for you. If you are new to space science, please go through the previous articles for a better understanding.We discussed a little about the propulsion of a rocket in the first article and we found that to propel a rocket in the desired direction we need to exhaust mass in the opposite direction. So, the primary objective of the propulsion system is to exhaust mass in the opposite direction of the motion of the rocket. The exhaust of mass generates thrust which tends to move the rocket in the desired direction. The generated thrust depends upon the exhaust velocity. The higher velocity of exhaust mass generates higher thrust.In a rocket, fuels are combusted in a Chamber in presence of oxidizers. Hot gases are generated in this combustion and these gases are exhausted through a Nozzle with a high velocity which creates the thrust to propel the rocket. Studies reveal that the velocity is directly proportional to the temperature of the combustion chamber. A higher temperature of the combustion chamber leads to a higher exhaust velocity of product gases and a higher thrust. So, fuels to be used are chosen such that they produce a higher temperature when combusted.
MS Dhoni
CONTINUE WITH II, MS DHONI International career:-Start of ODI career:-The Indian ODI team in the early 2000s saw Rahul Dravid as the wicket-keeper to ensure that the wicket-keeper spot didn't lack in batting talent.The team also saw the entry of wicket-keeper/batsmen from the junior ranks, with talents like Parthiv Patel and Dinesh Karthik (both India U-19 captains) named in the Test squads.2007 World Cup:-Preparations for the 2007 Cricket World Cup improved as India recorded identical 3–1 victories over West Indies and Sri Lanka and Dhoni had averages in excess of 100 in both these seriesIndia unexpectedly crashed out of the World Cup after losses to Bangladesh and Sri Lanka in the group stage. Dhoni was out for a duck in both these matches and scored just 29 runs in the tournament. After the loss to Bangladesh in 2007 Cricket World Cup, the house that Dhoni was constructing in his home-town Ranchi was vandalised and damaged by political activists of JMM. The local police arranged for security for his family as India exited the World Cup in the first round.Dhoni put his disappointing performances in the World Cup behind him by scoring 91* against Bangladesh, after India were left in a tight spot earlier in the run-chase. Dhoni was declared the Man of the Match for his performance, his fourth in ODI cricket. He was also later adjudged the Man of the Series after the third game of the series was washed away. Dhoni had a good Afro-Asia Cup, scoring 174 runs in 3 matches at an average of 87.00, with a blitzkrieg 139 not out off 97 balls, a Man of the Match innings, in the third ODI.Rise through ranks:-During the series between India and Australia in 2009, Dhoni hit an aggressive 124 runs in just 107 balls, in the second ODI, and a measured knock of 71 runs in 95 balls, along with Yuvraj Singh and saw India home by 6 wickets in the third ODI. Dhoni took his first wicket in international cricket on 30 September 2009. He bowled Travis Dowlin of the West Indies during a match of the 2009 Champions Trophy.Post 2011 World Cup:-n 2012, Pakistan toured India for a bilateral series for the first time in five years. In the three-match ODI series, Dhoni top scored for India in all three innings; however India lost the series 1–2. In the first ODI at Chennai, he helped India recover from 29/5 to help post a total of 227 in 50 overs. Playing a knock of 113 not out, he had a record partnership with Ravichandran Ashwin, although in a losing cause.Winning the 2013 ICC Champions Trophy, Dhoni became the first and only captain in international cricket to claim all ICC trophies. In the rain-shortened final against England, he was out for a duck and thus ending up the tournament with 27 runs from two innings. However, his field placements and tactics came handy, the team was successful beating the opposition by five runs. He was also named as captain and wicket keeper of the 'Team of the Tournament' by the ICCPost 2011 World CupIn 2012, Pakistan toured India for a bilateral series for the first time in five years. In the three-match ODI series, Dhoni top scored for India in all three innings; however India lost the series 1–2. In the first ODI at Chennai, he helped India recover from 29/5 to help post a total of 227 in 50 overs. Playing a knock of 113 not out, he had a record partnership with Ravichandran Ashwin, Test career:-Following his good one-day performance against Sri Lanka, Dhoni replaced Dinesh Karthik in December 2005 as the Indian teams' Test wicket-keeper.Dhoni scored 30 runs in his debut match, that was marred by rain. Dhoni came to the crease when the team was struggling at 109/5 and as wickets kept falling around him, he played an aggressive innings in which he was the last man to be dismissed. Dhoni made his maiden half-century in the second Test and his quick scoring rate (half century came off 51 balls) helped India set a target of 436 and the Sri Lankans were bowled out for 247.India toured Pakistan in January–February 2006 and Dhoni scored his maiden century in the second Test at Faisalabad. India was in a tight spot when Dhoni along with Irfan Pathan tried to steady the ship, with the team still needing 107 runs to avoid a follow-on. Dhoni played in his naturally aggressive style as he brought up his maiden Test hundred in just 93 balls after scoring the first fifty in just 34 deliveriesDhoni followed up the century with some prosaic batting performances over the next three matches, one against Pakistan that India lost and two against England that had India holding a 1–0 lead. Dhoni was the top scorer in India's first innings in the third Test at Wankhede Stadium as his 64 helped India post a respectable 279 in reply to England's 400. However, Dhoni and the Indian fielders dropped catches and missed many dismissal chances, including a key stumping opportunity of Andrew Flintoff (14).[110] Dhoni failed to collect the Harbhajan Singh delivery cleanly as Flintoff went on to make 36 more runs as England set a target of 313 for the home team, a target that India was never in danger of threatening. A batting collapse saw the team being dismissed for 100 and Dhoni scored just 5 runs and faced criticism for his wicket-keeping lapses as well as his shot . CAREER STATISTICSCompetition Test ODI T20IMatches 90 350 98Runs scored 4,876 10,773 1,617Batting average 38.09 50.53 37.60100s/50s 6/33 10/73 0/2Top score 224 183* 56Balls bowled 96 36 – Wickets 0 1 –Bowling average – 31.00 –5 wickets in innings – 0 –10 wickets in match – 0 –Best bowling – 1/14 – (MAHI ALWAYS BEST FINISHER)
Solid Propulsion System
Hello Reader!! Welcome to another article on Rocket Science. In this article, I will discuss the Solid Propulsion System. In the previous article, I discussed some basics of Rocket Propulsion. If you are new to Rocket Propulsion, please go through the previous article for better understanding.What is Solid Propulsion System?A solid propulsion system is a rocket propulsion system that uses propellants in solid form.In the first article, we discussed the similarity between a firework rocket and a rocket that is used for space exploration. A firework rocket can be considered as the simplest form of solid propulsion rocket. Here, Black Powder is used as a propellent. A paste of black powder and binder is inserted into the frame and it becomes solid after drying. This is ignited with the help of Magnesium Wire. Burning of black powder generates hot gas which is exhausted through a small vent in the downward direction and propels the rocket in the upward direction.In the case of a heavy rocket, different propellants are used and they are ignited with the help of an Ignitor. The generated hot gases are exhausted through the rocket nozzle with a high velocity generating upward thurst.Parts of Solid Rocket Motors:A Solid rocket motor consists of 3 basic parts: 1.Casing 2.Propellant Grain 3. Igniter 4.Nozzle Casing The casing is the cylindrical outer shell of a Solid Rocket Motor. It contains the propellant grain. The burning of propellant grain takes place inside the Casing. So, the casing can be considered as a Combustion Chamber.Propellant Grain Fuels and Oxidizers are mixed with some additional components (catalysts and binders) to make a paste and then the paste is given a particular shape and heated. Heat sets the paste and makes solid propellant grain.If the paste is set in the casing of the rocket, the grain is termed as Case Bounded Propellant Grain.If the grain is prepared in a different case and then inserted to the Casing of Rocket, the grain is termed Free Standing Propellant Grain.The geometric shape of the propellant grain is very vital for the performance of the rocket motor. We will discuss the Geometry of propellant grain after some time. Ignitor: Ignitor is used to ignite the propellant grain. There are different types of ignitors used in Solid Rocket Motors. The most popular type of ignitor is Pyrotechnic Ignitor. In this type of ignitor, pyrotechnic powder (materials that are easy to ignite) is used to generate a flame. Electricity is passed through a Nichrome wire to heat it and ignite the pyrotechnic powder. The pyrotechnic powder creates flame and ignites the propellant grain. Nozzle: The generated hot gasses are exhausted through a Convergent-Divergent Nozzle with a high velocity. Geometry of Propellant Grain:The generated upward thrust produced by a Solid Rocket Motor depends on the exhaust velocity of the exhaust gases. The exhaust velocity depends upon the pressure inside the chamber. Chamber pressure depends upon the area of the burning surface.Usually, the outer surface of the propellant grain is cylindrical. The inner surface varies according to the requirement. For different types of inner surfaces, the areas of the burning surfaces are different. So the generated thrusts are also different for different grains.So, the shape and geometry of propellant grain are designed according to the thrust requirements. But after the ignition, the thurst can not be regulated.Solid rocket motors are usually used in the Booster Stages of different Launch Vehicles. In the 1st stages (Booster Stages) of PSLV and GSLV, solid rocket motors are used.In some versions of PSLV, 6 Solid Rocket Strap-On Motors are augmented with the 1st stage.In GSLV, 4 Liquid Propulsion Strap-Ons are augmented with the 1st stage.
PROJECT MODEL ON SMART SIGNALLING SYSTEM FOR ELEPHANT CROSSING
Project model on "Smart Signalling System For Elephant Crossing"Introduction:- Smart Signalling System for elephant Crossing is based on Signalling System Project. In forested Area North of west Bengal Jalpaiguri, Alipurduar, etc Where a large number of elephant are died in train accident. So, It is an elephant safe from train accident project.Equipment Used:- LDR(Light Depending Resistor), IR sensor, 4 hole steel pipe,a Railway Wagon shape wood parts, Stone, Arduino Uno( For Programming), Male and Female Wire, Power adaptor or Power Source And colour for SketchMain Project Body:- Here a wood part, Shaped like railway Wagon and it is coloured.4 hole steel pipe set up four direction of wood and LDR are LED are set up on Steel pipe .at cross section. it covered full area.An Arduino Uno, for programming to activated a diiferent variation time.A power Adaptor for giving power to the Arduino Uno board.Male and Female wire for arduino set up.IR sensor for Signalling System and distance measureWorking Principle:-When a elephant is crossing on railway wagon the IR sensor Sensed that there are A BIG ANIMAL is there and it is informed to Driver and Station Master.If a small Elephant is entered there are present a LDR(light Depending Resistor) and it is informed to Driver and he stop the train and elephant is safe from accidentHere Four poles are set up in four direction and LDR set up at cross direction each other.If any thief entered he covered the LDR with a Small plate and he can loot the train and we are also think about this there are a Casine is used for every LEDThe LDR are set up a height that Size of ElephantAnd we have lastly think power source, there denest forest, Battery is the one solution to give power source when electric is not there and Battery is charged by Solar power Every 4 to 5 yrs electricians have to change the battery after 4 to 5 years So we are developing this model for better improvement. It is work in progress.
Liquid Propulsion System(UNIT -1)
Hello readers!! Welcome to another article on Rocket Science. In this article, I will discuss another type of propulsion system, Liquid Propulsion System. In the last article, I discussed the Solid Propulsion System. But there are some problems in using Solid Rocket Motor in the Upper-stages of a Launch Vehicle.Liquid Propulsion Systems are a little complicated with respect to the Solid Propulsion System. But we will keep our discussion simple. If you are new to this domain, please go through the previous articles for a better understanding.What is Liquid Propulsion Rocket?Liquid Propulsion Rockets are those rockets that use fuels and oxidizers in liquid form to propel in a particular direction.A liquid Propulsion system is generally termed as Liquid Propulsion Engine as it has moving parts.Advantages of Liquid Propulsion Engine over Solid Propulsion Motor:In the case of Solid Propellent rockets, the generated thrust can not be regulated after the ignition of the solid propellant grain. The thrust requirement is calculated before designing the propellant grain. So, they can not be throttled or restarted.But in the case of an upper stage rocket, the thrust may not be calculated in advance.For example, in the case of a satellite, the position and orientation always may not be perfect. Thrusters are required to bring them to a suitable position and orientation. The required thurst for this job varies and depends upon the satellite. Here Liquid Propulsion Engine comes into action. They can be throttled and restarted to produce thrust when required.How does Liquid Propulsion Engine work?In liquid propulsion systems, the propellants are stored in tanks and they are carried to the combustion chamber by some means. Then the propellants are injected into the chamber using an injector. There may or may not be an ignitor in the chamber. The propellants are combusted in the chamber and hot gasses are produced. These hot gasses are exhausted through the nozzle with high velocity. This generates thrust which propels the rocket in the desired direction.Different parts of Liquid Propulsion Engine:The liquid Propulsion system consists of four major parts: Propellant Tanks Feed System Combustion Chamber Nozzle CONTINUING...
Liquid Propulsion System(UNIT-2)
CONTINUE WITH 1...1. Propellant Tanks: In the case of Liquid propulsion, the propellants are stored in propellant tanks in liquid form. The tanks are specially designed to handle propellants in the state of weightlessness. 2. Feed System: Propellants are carried to the chamber from the propellant tanks with the help of the Feed system. For small rockets, Gas controlled feed system is used. For large rockets, a pump feed system is used where high-speed pumps are employed. To run these high power pumps a turbine is installed in the system.Propellants are injected into the chamber with the help of an Injector. Different types of injectors are used for different engines.3. Combustion Chamber:Propellants are injected into the combustion chamber with the help of injectors. Then the mixture of fuel and oxidizer is ignited with the help of a spark ignitor.In the case of some propellant, when the fuel and oxidizer come in contact, they ignite spontaneously. They are termed as Hypergolic Propellants.The propellants are ignited to produce hot gasses. 4. Nozzle: The generated hot gasses are exhausted through a Convergent-Divergent Nozzle with a high velocity. In GSLV, 4 Liquid Propulsion Strap-Ons are augmented with the 1st stage. These powered by VIKAS engine. In the second stage, the same engine is used.In the second stage of PSLV, the same engine is used. VIKAS Engine:Vikas engine is a liquid propulsion engine designed by Indian Space Research Organization in India. It is named after Indian Physicist VIKram Ambalal Sarabhai (Father of ISRO).This engine uses UDMH as fuel and N2O4 as an oxidizer.In the third stage of GSLV, a special type of engine is used, named Cryogenic Engine.These engines are much more complicated than normal Liquid propulsion engines.In the next article, we will discuss this type of engine and the story associated with it.That's all for this article. See you at the next one when we discuss Cryogenic Engine.
Orbit: The Path To Follow
Hello reader!! I will be discussing Orbits in this article. If you are new to space science, I would like to recommend you to go through the previous article for a better understanding.In the last article we got a new term, ‘Orbit’. What is an orbit?... How does it look like?... You may arise many more questions. So, let’s find out.What is an Orbit?An orbit is a path that is repeatedly followed by an object to move around another object in space. As you know, the earth rotates around the sun and the moon rotates around the earth. Each of them follows a particular path. These paths are called orbits.How does an Orbit look like?An orbit is a path to be followed. So, it can be considered as an imaginary line. Now, what is the shape of this path??.... It is elliptical (flattened circle) in shape. In some cases, it is nearly a circle, and sometimes it is highly eccentric. Comets have highly eccentric orbits. The object that follows the orbit is called a Satellite. It may be natural (Moon) or Artificial.How does an object stay in Orbit?If an object is in motion in an orbit it remains in the same orbit unless it is pushed or its motion is disturbed.Now we are in a good position to discuss earth’s orbit.You know about the Universal Gravitational Law, proposed by Sir Isaac Newton. Yes… I am talking about that theory which started with that Apple Incident. According to that theory, every object attracts another object with a certain amount of force. This force is termed as Gravitational Force.What happens if you push a ball in Direction 1???.... It tends to move in the same direction...But, what happens if you push the ball in both directions 1 and 2 at the same time??...... Yes, the ball tends to move in another direction between directions 1 and 2 as shown in the picture. This Motion is called Resultant Motion as it is the combined result of these two acting forces.Now, when an object is in motion, it tends to move in the straight path. But Earth attracts the object with some force which tends the object to move towards the earth. So, the resultant motion will be in a direction between these two motions. This resultant motion makes the object to stay in the same orbit. Without any push, it will always remain in the same orbit.Types of earth's orbit: Any path that can be followed to move around the earth, is Earth's Orbit. They can be classified depending upon their orientation & distance from the center of the earth.The angle between the orbit & the earth's equator is termed as Orbital Inclination The plane on which the orbit lies is termed as Orbital Plane.If the orbital inclination is nearly 90 degrees, the orbit passes almost above both the poles of the earth. This orbit is termed as Polar Orbit.If the orbital inclination is 0 degree, the orbit lies on the equatorial plane of earth. This orbit is termed as Equatorial Orbit.Now, we know, the earth rotates on its own axis and it takes 24 hours to complete one rotation, which is termed as Solar Day.But the actual time period is a little lesser, to be precise it is 23 hours 53 minutes 4.091s. This time period is termed as Sidereal Day. Now imagine, if you can place an object in an orbit whose orbital period is exactly the same as sidereal day, it will be stationary with respect to a particular longitude on earth. As the rotation of the object in this orbit is synchronized with the earth's rotation, this orbit is known as Geosynchronous Orbit.If the Geosynchronous Orbit lies on the equatorial plane, it is known as Geostationary Orbit. The height of the Geostationary Orbit is approximately 35,786 km from the earth's surface.To move an object from an orbit to a larger orbit in the same plane, the object needs to be pushed by some means. The intermediate orbit is termed as Transfer Orbit.Do you know about the GSLV and PSLV?? Those are Launch Vehicles operated by the Indian Space Research Organisation. GSLV stands for Geosynchronous Sattelite Launch Vehicle and PSLV stands for Polar Satellite Launch Vehicle.Now you have some idea about the significance of the words Geosynchronous and Polar. That's enough for this article.If you ever witnessed any Launch, you have heard of these phases :- "First Stage Separation Complete" "Second Stage Ignited" "Second Stage Separation Complete" Ever thought about their meanings??
MS DHONI,UNIT -I
CAPTAIN COOL(MAHI) Full name:- Mahendra Singh Pansingh Dhoni Born:-7 July 1981 (age 38) Place:- Ranchi,Bihar,jharkhand Batting:-Right-handed Role:- wicket keeperMahendra Singh is an international cricketer who captained the Indian national team in limited-overs formats from 2007 to 2016 and in Test cricket from 2008 to 2014. He is the only captain in the history of Cricket to win all ICC trophies. Under his captaincy,India won the 2007 ICC World Twenty20, the 2010 and 2016 Asia Cups, the 2011 ICC Cricket World Cup and the 2013 ICC Champions Trophy. A right-handed middle-order batsman and wicket-keeper, Dhoni is one of the highest run scorers in One Day Internationals (ODIs) with more than 10,000 runs scored and is considered an effective "finisher" in limited-overs formats.He is also regarded by some as one of the best wicket-keepers and captains in modern limited-overs international cricket.He made his ODI debut in December 2004 against Bangladesh, and played his first Test a year later against Sri Lanka. Dhoni has been the recipient of many awards, including the ICC ODI Player of the Year award in 2008 and 2009 (the first player to win the award twice), the Rajiv Gandhi Khel Ratna award in 2007, the Padma Shri, India's fourth highest civilian honour, in 2009 and the Padma Bhushan, India's third highest civilian honour, in 2018.[7] He was named as the captain of the ICC World Test XI in 2009, 2010 and 2013. He has also been selected a record 8 times in ICC World ODI XI teams, 5 times as captain. The Indian Territorial Army conferred the honorary rank of Lieutenant Colonel[8] to Dhoni on 1 November 2011. He is the second Indian cricketer after Kapil Dev to receive this honour.Dhoni also holds numerous captaincy records such as the most wins by an Indian captain in ODIs and T20Is, and most back-to-back wins by an Indian captain in ODIs. He took over the ODI captaincy from Rahul Dravid in 2007 and led the team to its first-ever bilateral ODI series wins in Sri Lanka and New Zealand. In June 2013, when India defeated England in the final of the Champions Trophy in England, Dhoni became the first captain to win all three ICC limited-overs trophies (World Cup, Champions Trophy and the World Twenty20). After taking up the Test captaincy in 2008, he led the team to series wins in New Zealand and the West Indies, and the Border-Gavaskar Trophy in 2008, 2010 and 2013. In 2009, Dhoni also led the Indian team to number one position for the first time in the ICC Test rankings.Dhoni also holds numerous captaincy records such as the most wins by an Indian captain in ODIs and T20Is, and most back-to-back wins by an Indian captain in ODIs. He took over the ODI captaincy from Rahul Dravid in 2007 and led the team to its first-ever bilateral ODI series wins in Sri Lanka and New Zealand. In June 2013, when India defeated England in the final of the Champions Trophy in England, Dhoni became the first captain to win all three ICC limited-overs trophies (World Cup, Champions Trophy and the World Twenty20). After taking up the Test captaincy in 2008, he led the team to series wins in New Zealand and the West Indies, and the Border-Gavaskar Trophy in 2008, 2010 and 2013. In 2009, Dhoni also led the Indian team to number one position for the first time in the ICC Test rankings.CONTINUE WITH UNIT -II
MS Dhoni
CONTINUE WITH-I In 2013, under his captaincy, India became the first team in more than 40 years to whitewash Australia in a Test series. In the Indian Premier League, he captained the Chennai Super Kings to victory at the 2010, 2011 and 2018 seasons, along with wins in the 2010 and 2014 editions of Champions League Twenty20. In 2011, In 2012, SportsPro rated Dhoni as the sixteenth most marketable athlete in the worldEarly life and backgroundDhoni studied at DAV Jawahar Vidya Mandir, Shyamali, Ranchi, Jharkhand where he initially excelled in badminton and football and was selected at district and club level in these sports. Dhoni was a goalkeeper for his football team and was sent to play cricket for a local cricket club by his football coach. Though he had not played cricket, Dhoni impressed with his wicket-keeping skills and became the regular wicketkeeper at the Commando cricket club (1995–1998). Based on his performance at club cricket, he was picked for the 1997/98 season Vinoo Mankad Trophy Under-16 Championship and he performed well. Dhoni focused on cricket after his 10th standard. Dhoni was a Travelling Ticket Examiner (TTE) at Kharagpur railway station from 2001 to 2003, under South Eastern Railway in Midnapore (W), a district in West Bengal.Early careerIn 1998, Dhoni was selected by Deval Sahay to play for the Central Coal Fields Limited (CCL) team. Till 1998 Dhoni, who was in class 12th in school, had played only school cricket and club cricket and no professional cricket. One of the famous episodes, when Dhoni used to play for CCL, was when Deval Sahay used to gift him Rs 50 for each six that he hit in Sheesh Mahal tournament cricket matches.Bihar cricket teamDhoni made his Ranji Trophy debut for Bihar in the 1999–2000 season, as an eighteen-year-old. He made a half century in his debut match scoring 68* in the second innings against Assam cricket team.Dhoni finished the season with 283 runs in 5 matches.Jharkhand cricket teamDhoni's performance in the 2002–03 season included three half-centuries in the Ranji Trophy and a couple of half-centuries in the Deodhar Trophy, as he started gaining recognition for his lower-order contribution as well as hard-hitting batting style. In the 2003/04 season, Dhoni scored a century (128*) against Assam in the first match of the Ranji ODI tournament. Dhoni was part of the East Zone squad that won the Deodhar Trophy 2003–2004 season (CONTINUE WITH UNIT III)