Myself Dr. Nitin Gramopadhyay working as assistant professor in Department of Humanities and Basic Sciences. Today we are going to learn a topic fuel and a particular beat from that topic that is determination of calorific value of a given sample of fuel. This is the learning outcome for today's session. At the end of this session students will be able to describe determination of calorific value of fuel by using Boy's calorimeter method. This is the content we are going to learn. First we will learn the definition of calorific value of fuel, then we will see the diagram of Boy's calorimeter, then construction and working of Boy's calorimeter, observations of the experiment and finally, we will learn how to derive the equations to calculate higher calorific value and lower calorific value of a given sample of fuel that is HCV and LCV equations. Now, as the today's beat is related with determination of calorific value of a fuel. So, first we will learn what do mean by calorific value of a fuel. It is the capacity of a fuel sample to evolve the heat, therefore calorific value of a fuel is the total quantity of heat liberated when a unit mass or volume of the fuel is burned completely. So, what is calorific value? It is nothing but the total amount of the heat evolved by burning a unit mass or volume of a fuel. We have three types of fuels such as solid, liquid and gas. Solid fuel possesses lower calorific value, liquid fuel possesses moderate calorific value and gases fuel possesses higher calorific value. Now, calorific value of a fuel sample can be determined by the following methods. For solid and non-volatile type of fuel, bomb calorimeter experiment is used and for gaseous and volatile type of fuel, Boyd's calorimeter experiment is used. Whereas, for all types of fuel we can find out the calorific value by using Duelong's formula which is also called as theoretical determination. But the Duelong's formula we can use only when we know the composition of the fuel. So, we will come to our beat that is Boyd's calorimeter experiment. First we will see the diagram of Boyd's calorimeter. The apparatus is used to find out the calorific value of gaseous as well as volatile type of liquid fuels. The apparatus consists of the suitable gas burner in which the known volume of gas at known pressure can be burned at uniform rate. On the burner there is a combustion chamber which has a copper tubing coil inside as well as the outside. So, this is the combustion chamber, this is the burner and this is having the pressure regulator through which we can adjust the flow of the gas and when gas undergoes the combustion process, it evolve the combustion products which are accumulating inside the combustion chamber. Water at constant rate is passed through the coil. Water enters from the top of the outer coil. See here the first water moves from the top of the combustion chamber which is also called as the inlet water which goes down from the inner as well as outer coils and finally it exits from this vane and which is known as the outlet water. The thermometer T1 and T2 gives the temperature of inlet water and outlet water respectively. During the process of combustion when we circulate the water, it flows down and up through the coil the flow of the water takes away practically all heat of the combustion and as a result of that the combustion product get condensed and the steam which is formed during the combustion gets condensed as condensed steam which can be collected at the bottom of the tray, the whole assembly is properly enclosed in a insulating chamber to avoid the loss of heat by radiation. Now we will see how it works. First the circulation of water and burning of gases fuel are continued at constant rates for about 15 minutes for initial warming up period. The rates of fuel burning and water circulation are controlled so that the exit water leaves the apparatus nearly at atmospheric pressure. When the steady conditions are established then the readings are taken simultaneously. Now here I would like to ask you one question, Boyce calorimeter is used for determination of calorific value of option A solid fuel, option B non-volatile liquid fuel, option C gases fuel and option D both B and C. For a moment and the correct answer is option C gases fuel. Now these are the observations of the experiment. The first observation is volume of gases fuel burnt at standard temperature and pressure that is denoted as V meter cube. So we are measuring how much volume of the gas we are allowing for going combustion process and that is denoted by in meter cube V in meter cube. Then second is the weight of water used for cooling. So if you remember the diagram the water enters from a inlet vent which is circulating through the combustion chamber just to condense the products of combustion and therefore the second observation is that how much water we require to do the condensation of all the combustion product and that is denoted by the W gram that is weight of water used for cooling W gram. Then the initial temperature of water which is also known as the inlet temperature of water that is T 1 degree centigrade and the second that is final temperature of water which is also known as outlet water temperature that is T 2 degree centigrade and H C V of the fuel is nothing but L calorie per meter cube. Now we will see the calculations heat liberated is equal to L V because heat liberated is a product of the capacity of that fuel to supply the heat multiplied by its quantity. So L is a calorific value H C V and V is a volume so the product is nothing but the heat liberated and heat absorbed is equal to W into bracket T 2 minus T 1 degree centigrade. So therefore what happens heat liberated is always equal to heat absorbed and therefore L V is equal to W into bracket T 2 minus T 1 degree centigrade because heat liberated is always equal to heat absorbed. Now I will replace L with H C V here we can see that key H C V is equal to W into bracket T 2 minus T 1 degree centigrade divided by V where W is mass of water used for cooling T 2 is temperature of outlet water T 1 is temperature of inlet water and V is volume of gas burned in meter cube. So this is about H C V. Now we will see how to calculate the L C V. L C V is nothing but the lower calorific value which is also known as a net calorific value and how it is determined? It is determined by using this equation that is L C V is equal to H C V minus M multiplied by 587 divided by V where M is mass of steam condensed. So if you remember the diagram and the working of the experiment what is the main objective of the experiment we are allowing the fuel that should undergo the process of combustion and as a result of that whatever the combustion products are forming these are condensed by circulating the water through the combustion chamber. And therefore that is collected as that is steam at the bottom and that is denoted by small m that is small m is equal to mass of steam condensed. So all that slides are prepared by using a textbook of engineering chemistry written by Jain and Jain. Thank you.


I'm Dr. Rashouk Bhatt. I'm a consultant nephrologist working at KMC Hospital-Lambedkar Circle for the past 16 years. I'm here today to talk about chronic kidney disease. This is an important disease affecting millions of people worldwide and is also an important health hazard in our country. The disease causes significant morbidity and mortality and also substantial financial burden to patient and his or her family. However, if this disease is detected early, it can be treated effectively and the treatment can be relatively inexpensive and the results are likely to be good. However, once the disease reaches an advanced stage, the treatment is very expensive and the results can be suboptimal. Now, chronic kidney disease or short forms CKD is a disease in which the kidney function deteriorates slowly over a period of months to years and it progresses through several stages. Usually we recognize five stages in the progression and the final stage is known as a stage of kidney failure at which the patient requires dialysis or kidney transplantation. There are numerous causes for chronic kidney disease but the two most important among them which constitute almost 50% of cases of chronic kidney disease are diabetes and high blood pressure. In addition to this, the other causes could be in the form of glomerulonephritis, hereditary kidney diseases, kidney stones or obstruction to the urine flow in the urinary tract, repeated infections of the kidney, the urinary tract could be some of the other causes. It would be appropriate if we call chronic kidney disease a silent killer. The reason is that it is very difficult to identify this problem in its early stages. You would be surprised to know that majority of the patients who have chronic kidney disease are totally asymptomatic in the early stages of the disease. Once the disease progresses and reaches the terminal stages, patient starts getting various symptoms in the form of nausea, vomiting, breathlessness, loss of appetite, itching, swelling all over the body, excessive tiredness etc. By this time patient usually has reached a terminal stage known as stage of kidney failure and there is hardly any reversal from this point onwards. So then how do we recognize chronic kidney disease early would be the question that you would ask since the patient is asymptomatic, how should we know it? So basically this is detected by a process known as screening. By screening I mean patients who are asymptomatic but who are at risk of chronic kidney disease get certain routine tests done irrespective of whether they have symptoms or they are asymptomatic. Now what are these tests? These tests are relatively inexpensive and simple. This includes a simple blood test whereby we measure the level of a substance called creatinine in the blood and based upon the estimation of the level of the creatinine we would be able to assess what is the level of kidney function of the patient. In addition we do a urine test to look for protein as well as blood in the urine and the presence of either of these would suggest that the patient is suffering from kidney damage. So the next question arises as to who has to be screened. Now if you are at risk for chronic kidney disease then you need to get screened whether you are symptomatic or not. So who are these patients at risk?  And these screening tests are inexpensive and if these tests are positive and you are diagnosed to have chronic kidney disease then further evaluation may have to be done to stage the disease, to find out the cause of the disease and look for any reversibility and also to look for complications of chronic kidney disease. So by this method if we identify patients early then the progression to kidney failure can be substantially retarded and in some instances halted and in some instances like in case of glomerulonephritis or obstruction to the flow of the urine if these are treated effectively restoration of kidney function is also possible in a number of cases. So how to go about treating chronic kidney disease once diagnosed? Now this what I am going to say is the most important pillar of treatment of chronic kidney disease that is control of blood pressure, control of blood pressure and control of blood pressure. Now any patient with chronic kidney disease he or she should have his or her blood pressure brought down to less than 130 by 80 and should be maintained at this level consistently throughout his or her life to be effective. Now the most important thing to note here is that unlike simple hypertension which affects majority of the people blood pressure in patients with chronic kidney disease is highly resistant. So it is unlikely to come under control with the use of only one drug. Patients usually require multiple medications to bring the blood pressure under control and many of them may require maximum doses of these medications to bring blood pressure under control and you can understand that the same drug may not work the same way in two different individuals. So there is no one size fits all theory here. So it has to be tailored depending upon the requirement of the individual patient and no doctor on a single visit can tell you that you require these many BP medications and this is the dosage that you need. Hence early on the number of visits that you may have to do to get your blood pressure under control may be frequent but once the blood pressure comes under control the frequency of visits can be reduced. However adherence to treatment throughout your lifetime is mandatory and blood pressure should be brought and kept below 130 by 80 consistently for you to achieve good results. Now among the blood pressure medications we most often use drugs belonging to a group called asinibiters or angiotensin receptor blockers. These drugs have got additional beneficial effect over and above the other routine antihypertensives in reducing proteinuria and also preventing progression of chronic kidney disease. So unless otherwise contraindicated one of your antihypertensive drugs should be either an asinibiter or an angiotensin receptor blocker. Now in addition to control of blood pressure in diabetics it has been found that a good control of blood sugars keeping the glycated hemoglobin to less than 7% has helped in preventing progression of the disease. In addition to this diet plays a very important role. Salt restriction, restriction of proteins in the diet especially from animal sources meat and poultry can help in retarding progression. Avoidance of smoking if you are a smoker helps in preventing progression. Similarly if you are overweight bringing down your weight to normal limits also helps in reducing the progression of kidney disease. In addition to all these patients who have diseases like glomerulonephritis may have to be treated with immunosuppressants and patients who have obstruction to the urinary tract may have to undergo surgical intervention to help to improve their kidney function. These are all about what you have to do but there are a list of don'ts also. One of the important things which CKD patients should know is the drugs that they need to avoid. It is very dangerous for a chronic kidney disease patients to self-medicate or to take over the counter medications. There are several medications which can cause sudden onset loss of kidney function in these patients which include painkiller medications belonging to the class called NSAIDs, some antibiotics, certain contrast agents which are given during procedures like CT Scran, angiogram etc which these patients will have to avoid. In addition the doses of several medications may have to be modified depending upon the level of kidney function. Herbal medications are also not safe. People often take herbal medications thinking that they are safe and they may help to improve their health but there are several reports of herbal medications associated with these properties and worsening of kidney function. Therefore my advice to you would be not to use herbal medications. Now all these treatment modalities which I have listed out would be effective if it is started early in the course of the disease and their effectiveness decreases as stage of the disease progresses. Once the patient reaches an advanced stage we would be grappling more with the complications of the kidney disease and treatment of them rather than preventing progressions. So we may have to manage anemia, we may have to manage mineral and bone disorders, fluid overload and so on. And once the patient reaches the stage of kidney failure then the only treatment options that are available are dialysis and kidney transplantation. So my message to you would be help us to help you to prevent kidney failure. If you are at risk please report early, get tested. If you have the disease start preventive measures early and adhere to them throughout your life and prevent kidney failure.


This video is the third in a series on the Chernobyl disaster. The first video started with the precursor event, the Leningrad 1975 meltdown. The second video, titled Chernobyl Part 1, covers the fateful failure of the RBMK at Chernobyl Number 4. And finally, this video, which will look at the aftermath and clean up from one of the world's worst pollution events. I'd recommend watching the previous two videos if you haven't done so already. But now, let's begin the final episode of my Chernobyl series. It is February 2022 and Russian soldiers have crossed the Belarusian-Ukrainian border and have been ordered to occupy the Chernobyl Exclusion Zone. The site offers political capital in the Russian invasion. It has the potential to be a future bargaining chip for any negotiations, but maybe more importantly, it represents a logistic benefit. In that, it is in a direct line between Belarus and Kiev. The Ukrainian guards are arrested and bundled into a basement. The technical staff, however, are allowed to continue their work keeping the site relatively safe. All around the site of the 1986 Chernobyl disaster, Russian soldiers dig in. They excavate trenches and make dugouts. Either from ignorance, blindly following orders, or the fear of catching a Ukrainian bullet have led these men to be digging up some of the world's most contaminated soil. Reportedly, they even dig up parts of the infamous Red Forest, although an estimated 1500 soldiers have been told to hold the area, a reported 10,000 vehicles have driven through the Exclusion Zone, potentially spreading contaminated soil for hundreds of miles. Towards the end of March, and with hopes of a lightning invasion of Ukraine fading away, the soldiers are ordered to withdraw. This is the most recent chapter in the Chernobyl story, but it only represents a small part of the legacy that continues to cast a shadow over the region. My name is John and today we're looking at the cleanup and containment of the Chernobyl nuclear reactor disaster. It is April 1986 and Soviet authorities are desperately trying to take stock of the unfolding nightmare at Chernobyl nuclear power station. In the immediate days and weeks after reactor 4's failure, focus was firmly put on trying to contain the spread of radiation. This involved the use of personnel to remove debris from the turbine hall roof in preparation for the construction of the sarcophagus, as well as miners working below the reactor hall to install a shield to prevent the core from melting through to the water table. These people were known as the liquidators, but as I alluded to in my previous video, this was just the tip of the human iceberg. You see the term liquidator is actually a bit of a catchall that covers the first response teams all the way to the police, on the streets, directing personnel and vehicles. And the doses they received reflected the work they undertook, with an official death toll of 28 from radiation sickness in 1986. Some 600,000 would be involved in the wider region cleanup activities between 1986 and the present day, but in the immediate aftermath of the core uncovering and 10 day fire, a massive region wide project was beginning to form, in evacuation and decontamination of a 30 kilometer radius exclusion zone. The Soviet authorities were eager to begin cleaning activities as quickly as possible. In a case of trying to snatch some kind of victory from the jaws of defeat. If the affected regions could be repopulated quickly, then maybe, just maybe, it would soften the international embarrassment and reclaim some glory for the socialist utopia the USSR claimed to be. However, this ambition to clean up as quickly as possible came at a cost, much like the men sent to top the roofs of the reactor buildings to collect contaminated rubble, the exclusion zone would require people, and lots of them, to work for hours, days, weeks and months on end amongst the fallout. Needless to say, the health of many would become a long lasting legacy. The exclusion zone was initially an arbitrary 30 kilometer radius around reactor 4, and was split up into 3 areas, and as such, different protective clothing and precautions were required, the first of which was a 10 kilometer radius around the nuclear plant, and was designated the black zone. This had radiation levels of over 200 microcevets an hour, if you were evacuated from here, you'll never be allowed to return home. The next area was called the red zone, and had radiation levels of between 50 and 200 microcevets an hour, and here evacuees might be able to return once radiation levels normalize. The final area was the blue zone, with levels between 50 and 30 microcevets an hour. Here, children and pregnant women were evacuated throughout 1986. The region was home to approximately 120,000 people, spread out amongst Pripyat, the city built for the workers at the plant, Chernobyl, and just under 200 smaller settlements. A total of 92,000 would be evacuated throughout the summer, but the number would rise in the wider region, with children being evacuated as far away as Kyiv. As a side note, the exclusion zone was home to a pretty horrific local landmark, known as the Partisan Tree, and was essentially used by the Nazis as their very own Ukrainian Tibern Tree. Soviet soldiers and partisans were hung from the tree during the Second World War by the invading Germans. It is an extraordinary looking tree, I mean just look at this picture. It is the stuff of nightmares, and actually survived 1986 by quite a few years, all the way into the 1990s, surprising as it was only 1600 meters from reactor 4. Its striking trident shape became somewhat of a local icon, but I digress. As time went on, the boundaries of the zones began to follow the areas more contaminated than arbitrary lines on the map. You see the wind in the following days and weeks after the disaster dictated the hot spots of contamination. Although the plant was in Ukraine, some of the most affected areas were in Belarus. As time went on, the exclusion zone would expand, encompassing an area of 2,600 km2. But contamination wasn't limited to just the exclusion zone. Officially to enter the exclusion zone, you would need to pass multiple checkpoints and sanitation stations. The closer you got to the black zone, the more protective equipment was required from a simple mask at the end of the zone to full hazmat towards the epicentre. But as the full scope of the cleanup work became ever more apparent for the liquidators, some of these rules were relaxed. The zone by the summer increasingly looked like a military camp, with cleanup teams billeted in tents. Some higher-ranking officials, however, had taken up residence in the abandoned city of Chernobyl, where the nuclear power plant got its name from. As April gave way to May, and some of the areas had been evacuated, the mass clean-up began. The task of cleaning up the area would officially, and I say in quotation marks, start off by a team of dosimetrists driving through the area in a specially shielded vehicle. They would work out the safest way to enter and exit an area. As well as get readings of the radiation any workers would be exposed to. This would determine how long a worker could operate in an area. A limit of 25 runtguns was set. Once this was reached, the worker should be rotated to a different role away from any contaminated area. Although in reality, this limit was exceeded, where the ready supply of willing volunteers gradually dwindles away. Once given the okay to enter, liquidators would have a free-stage process of cleaning up. The first was to remove the top layer of soil. The official depth was 30 centimetres, but reports seem to suggest that as little as 10 centimetres was taken in some places and as much as 50 centimetres in others. Ranging from hand tools up to diggers, the liquidators removed the soil and placed it into metal containers that were sent to a radioactive waste dump. The soil was contaminated with but not limited to strontium 90, cesium 137 and plutonium. The next stage was to soak everything, houses, roads, heavy equipment and vehicles in a special solution. The water then was as best as possible collected and again placed in metal containers to be sent to a waste facility. The final stage was to spray the ground with another solution which created a film to encapsulate radioactive dust to then be scooped up and again sent to a waste facility. But that is really just the tip of the iceberg. In many areas within the exclusion zone, houses had to have their roofs removed and replaced, roads had to be machine washed or even re-asphalted, fences replaced, water pipes removed and replaced and new wells dug. Up to 60,000 buildings were cleaned including 500 population centres of varying sizes. Conditions for the workers were not great, which led to many volunteers refusing to work. Every person was meant to be issued with a personal dosimeter, but unsurprisingly due to the vast scale of the cleanup project, this didn't happen. Many continued to be housed or better described not housed in tents, even after proper accommodation was apparently allocated. In November 1986, control of the cleanup and remediation project was taken over by a new production association, COBINAT. The organisation was based in Chernobyl City and was tasked with operating and decommissioning the NPP. Continuation of decontamination efforts, run the supply lines into the zone and oversee the construction of a new city outside the zone for displaced persons. The city would be called Slavutage, but we will come back to this a bit later. One of the most polluted areas known as the Red Forest, 10 square kilometres of woodland had its pine trees bulldozed and buried. The area was then covered in sand and replanted with new pine saplings. The area got its name from the colour the trees went after becoming contaminated and subsequently dying. But where did the liquidators come from? Well really, it was a mixture. The initial attendants were ordered to be there, for example the firefighters, miners, transport workers, police and military personnel. Reservists were also employed and any who refused were socially and politically punished. But a large proportion were volunteers. Some were drawn by the money on offer, others a sense of public duty, and many were students, training to become firefighters, police or ambulance workers. There were many cases of liquidators keeping on working past their 25 runtkins due to the lack of replacement and with others continuing due to bravado. The overexposed liquidators have cast a long shadow over the region and has become a medical and social issue even till today. It is estimated that 600,000 people deemed liquidators took part in the cleanup. Needless to say, this has proven a terrible headache for healthcare infrastructure in the region. Liquidators would work on different parts of the exclusion zone for many decades to come. Strangely, although abandoned, Pripyat Swimming Pool was kept in use until 1998 for exercise for inner zone workers. Depending on who's asked, the time required for the exclusion zone or locally known as a zone of alienation to become habitable again ranges from between 320 and 10,000 years. The former figure was from the Ukrainian government and the latter from Greenpeace. Wildlife within the exclusion zone flourished with nature taking back the previously human occupied areas. With no pesky people around to encroach upon their habitat, animals populations have soared. With even bear sightings, animals that were pretty rare pre-1986, studies on birds from the more contaminated areas have shown to have smaller brains than that of species from healthier areas. Vutation deformations have been observed and population densities are noted to be lower in higher contaminated areas. Throughout the cleanup of the different zones and their eventual return to nature, the Chernobyl nuclear power plant loomed in the distance, including its often forgotten still running reactors. But what of the other reactors? The self-deconstruction of Unit 4 didn't negate the need to safely operate the other three operational reactors. It didn't even immediately put an end to Units 5 and 6 which were planned and under construction. Based with the prospects of energy shortages, reactors 1, 2 and 3 were allowed to continue operation by the local authorities. The USSR had no choice anyway as its economy wasn't in the best shape and with nuclear power any option would cost a lot of money. If they shut down and decommissioned the reactors, they would incur the cost of dismantling and dealing with the waste, something that has recently started at the Dungeon S nuclear power plant in Kent.  Also, once gone, where are you going to get a power source to pick up the deficit the closure of Chernobyl would create? You'd have to build multiple more conventional power plants, all of which costs money. This left, at least for the short term, the less costly option of keeping the remaining reactors online. Because at Chernobyl the reactors were of two designs, being that 1 and 2 were of first generation and 3 and 4 were of second generation, RBMK, the units were paired up. This meant to safely operate Unit 3, the connecting areas with 4 had to be filled in with concrete, but the early 90s would see another accident at Chernobyl. Just a couple of months after Ukrainian independence was declared, Unit 2 experienced a fire in its turbine hall on the 11th October 1991. The event wrote off Unit 2, resulting in it requiring decommissioning. The fire showed the ongoing risk of operating the plant. The first generation RBMK design was showing its age, and after the fire was most certainly proving to be a liability. Because of this, a deal was struck between several international agencies, including the IAEA, requiring Chernobyl NPP to be shut down and decommissioned. This started in 1996 with Unit 1 going offline, followed by Unit 3 four years later. On the 15th December 2000, the president of Ukraine, Lenid Kuchma, turned off reactor number three in an official ceremony. Although now officially shut down, there was an even bigger issue to deal with. All of that used fuel. The origin site was not sufficient for all the additional waste, meaning a new site was required. In 1999, a contract to construct a dry waste management area designated ISF-2 was signed. 12 years later, construction began, being completed in 2017. ISF-2 became the world's largest nuclear fuel storage facility, and is estimated to be able to hold more than 21,000 fuel assemblies for at least 100 years. I mentioned in my Chernobyl Part 1 video the construction of the sarcophagus, but this wasn't the magic bullet of containment. I mean, it wasn't ever intended to be permanent, because of the speed in which it was built, and the amount of radiation it would be subjected to, that would eventually cause damage to the structure. Such intensity was the radiation during the sarcophagus' construction. That crane operator cabs had to be lined with thick lead shielding, and even then working times were closely monitored. The sarcophagus made use of some of the walls of the reactor building to support the main roof beam. This helped with the speed of installation, and although reinforced in places, serious damage had been received during the accident. Multiple boreholes were drilled into the roof to facilitate exhausting and filtering of radioactive gases. When it was completed in November 1986, the sarcophagus held in 200 tonnes of reactive lava-like corium, 30 tonnes of highly contaminated dust, and 16 tonnes of uranium and plutonium. By 1988, assessments of the structure showed its life expectancy to be a maximum of 30 years. This was probably ambitious, and as such, the international community started to show signs of wanting to help. Soon enough, a more refined form of confinement was beginning to be conceived. The sarcophagus was the best in a bad situation, and a new safe confinement was intended to go over the sarcophagus and the reactor building. After being successfully installed, the original confinement structure will then be demolished. It is truly an impressive idea, requiring the newly independent Ukrainian government to hold an international competition for proposals to replace the sarcophagus in 1992, but it would take over a decade of planning and design competitions. But in 2004, a tender was announced, generating two bids. Sadly, this wouldn't lead to much. Eventually, a consortium of French companies would be awarded the contract in September 2007, 21 years after Unit 4 turned its fuel into molten lava. Construction costs were estimated at $1.4 billion, with a project timeline of five years. Spoiler alert, they may have had to have doubled that. But let's look at the design of the new confinement structure. The 100-year life expectancy structure consists of 13 arches, assembled 12.5 meters apart, with a height of 110 meters. Between the arches, a tubular steel lattice was built, which was then clad with three layers, totaling a thickness of 10 meters. Polycarbonate panels cover each arch to prevent the accumulation of radioactive particles, and warm air is circulated to reduce the risk of corrosion. The structure's width is 165 meters, and is long enough to cover the entirety of Unit 4 and its sarcophagus. The height is oversized to allow machinery to be attached to the arches to allow for dismantling of the original structure. Even more fascinating is that it was built not over the reactor, but to its side, meaning that upon completion of construction, it was designed to slide over Unit 4. It was built on retaining walls independent from the damaged reactor building, allowing for a full demolition of the old structure. Construction began in 2010 and two years later the first steel sections were beginning to be erected. In April 2014, the first steel section was moved into a parking position to allow further arch construction. And two years later, in April 2016, the final arch was completed. Just a few months after that, the vast structure was getting ready to be moved into its final resting place. After 15 days of movement, on the 29th November 2016, the new containment structure was in position. But yet again, another two years would be needed to finish off the project officially, when it ended in July 2019 with the sarcophagus being sealed under the monumental steel structure. At the time of its movement, it was the largest movable man-made structure in the world, and the project's final price tag was over 2.1 billion euro. Although delayed, it is a success. But this only marks the start of the reactor's dismantling project. Dust within the shelter is constantly monitored with hundreds of sensors all throughout the structure. The radiation exposure of staff is recorded and tallied up, allowing for a maximum yearly dose of 20 millisieverts, or apparently 12 minutes of standing on the sarcophagus roof. So far, the whole disaster has cost $68 billion and has affected millions of lives, and it looks like it will continue to do so. Less than 100 deaths are officially linked to the disaster. But the long-term effects have caused increased numbers in thyroid cancers, birth defects and infant mortality. In 2019, a gradual but worrying rise in neutron rates started to be recorded. These were thought to be coming from the depths of the damage fuel in the reactor hall. It is thought, strangely, that the drying of water in the reactor hall basement, instead of stopping a chain reaction by removing a moderator, was actually doing the opposite. Although to much relief, the steady increase of neutron started to peter out in 2021. Unit 4's ability to surprise the international community is clearly still a looming spectre, reminding us we still aren't finished. Covid, of course, affected work on sites slowing down remediation works. But just as we thought things couldn't get any worse, the risks of one of the world's most contaminated sites came back into the news headlines. And this brings us back to the Russian soldiers in the exclusion zone. During the initial occupation of the Ukrainian-Russian war, power was cut to the power station for three days, requiring technicians to beg, borrow and steal fuel to power generators. But with Russia changing its target from Kyiv to the Donbas, soldiers left the exclusion zone. Their occupation has made the site far more dangerous, as in their wake, landmines and contaminated equipment has been left behind. But although the occupation of the region represents a political and environmental disaster, amazingly scenes of defiance were shown in the city of Slavych, the home of many evacuees from Pripyat. Russian troops entered the city and detained the mayor Yuri Formityev. Outrage by this, locals took to the streets to protest the occupation. Even flashbangs and warning shots from the Russian forces failed to disperse the crowd. Seeing such resistance to occupation, the soldiers agreed to leave and release the mayor. After the Russian withdrawal from the exclusion zone, Ukrainian soldiers and National Guards went into examine the abandoned dugouts and trenches. Little precautions seem to have been taken by the soldiers and it is likely this will come back to haunt them in later life. Some of the radiation monitors found dates back to the 1950s and were far from capable of providing any benefit. Contamination is likely to be spread to Belarus throughout Ukraine and even back to Russia. Chernobyl would likely be in news cycles for decades to come as political, scientific and economic uncertainty can all affect the management and clean up operations. Right work goes without saying with such a massive disaster as Chernobyl, this video is just the tip of the molten uranium iceberg and I strongly recommend having a look at the references in the video description for further reading. This should be my last video on Chernobyl but will probably change when we find out the true scale of the Russian army's contamination spread.


Maverick is a ride that is somewhat nostalgic for me. I became addicted to coasters in 2005 as I visited Cedar Point a lot being my home park. I decided to start riding coasters and the year after that speculation arose about Cedar Point's next coaster. Things were really fueled when Red Intamin Track showed up at the Hotel Off Property. So this was my first taste of roller coaster speculation really. So that's pretty awesome. And Maverick is definitely an awesome ride. So today I'm going to be reviewing Maverick, giving my overall thoughts on the ride, what I like about it, maybe some things that could be improved. So stay tuned. Maverick is a pretty short ride that really packs a punch. This is one where the size is kind of deceiving. It is only 105 feet tall. The drop is 100 feet, but it has a great 95 degree drop. So it's beyond vertical and you get a crazy pop of ejector airtime, especially if you're sitting in the backseat. Maverick is a multi-launch Intamin Blitz coaster. It has two launches. The first one is actually sort of a lift-till. It's an LSM lift-till, so it propels you up to the top very fast. I kind of think of it as sort of in between, you know, a cable lift and what you would think of as a typical launch. It's pretty fast, but it's not like an intense launch, but it definitely whips you over the top very quick, and that's awesome. And then the second launch is where you hit your top speed of 70 miles per hour. Maverick has a trek length of 4,450 feet. So it's a very long ride. Features two inversions. When it was announced, it was originally announced to feature three inversions. There was going to be a heartline roll after you come out of the left-hand curve following the second launch, but it was found to cause too much stress on the track, and it would have been too forceful for riders, so it was ultimately removed. So it features two inversions, which is the twisted horseshoe roll, essentially two corkscrews that go in the opposite direction consecutively. Maverick is a long ride. It's very smooth. It's fast. It's very quick. It has lots of really quick transitions, so you're just getting whipped to left and right. And it does not focus on airtime, but there's a couple really strong moments of ejector airtime. Some of the best airtime in the park as far as quality of airtime goes. After you're going on the first 95-degree drop, you go around this S-curve, then you hit a camelback hill, which provides an awesome moment of ejector airtime, and then that's when you go into the horseshoe roll, and then you turn right into the second launch. You stop for a few seconds, and then you have these lights that start the flash, and some cool effects in there, and then you hit that 70 mile per hour launch, and the acceleration is really quick on that. It's awesome.  So Maverick really has a lot going for it. Maverick is really one of the most intense coasters that I've been on. Despite its small stature, not being a huge ride, this really serves as a great example of how a ride doesn't have to be record breaking to be a great ride. I look at rides like Maverick and Valravn, and it's just day and night to me. Valravn is a huge dive coaster, standing at 223 feet tall, and I just find it so force-less, and I was just really disappointed by my experience on Valravn. Maverick on the other hand is a really intense ride, lots of interesting elements, some great airtime, just all around really good. The restraints on Maverick actually, when it opened, used to be these hard over-the-shoulder restraints, and they were kind of uncomfortable. I don't remember having a huge issue with them, but they were slightly uncomfortable, and in 2013 they were replaced with soft over-the-shoulder restraints, and these are great. I-305 has the same exact ones, and these are really comfortable, you don't really get any headbanging, so I don't have any problems with them. Maverick took the spot of the former classic log flume, Whitewater Landing. The Whitewater Landing loading station was utilized as you walk through the queue in that building. A lot of the queue is housed in the old Whitewater Landing station, so that's really cool that they were able to incorporate that into Maverick to sort of pay tribute to that. You still have the Whitewater Landing logo even on the roof, and that's really cool. Maverick is a very well presented ride, doesn't have a lot of theming being Cedar Point, so it's not fair to base any of this review off of the theming really, but the little theming that is there is very well presented. Aesthetically it's a very nice ride, and it just has a great atmosphere surrounding it. The operations on Maverick are great. Maverick has five trains, and usually it's running most or all of the trains, so it definitely has a great capacity. Even if the line is fairly long on this, it moves pretty quick. Maverick is one of my favorite roller coasters to date. It's generally considered to be one of the best coasters in the world, and I definitely would have to agree. Maverick is going to get an overall score of 9.5 out of 10 for me. It does have some reliability issues being an Intamin and having a couple launches. It goes down somewhat frequently, but not too often. It's not real hard to get on this ride, and overall it's a near perfect ride. It has a couple awesome airtime moments, a lot of intense twists and turns, and it's just a really fun ride. So let me know in the comments what you think of Maverick. Be sure to like this video and subscribe to my channel for more roller coaster and amusement park content. I've got lots of reviews coming in the near future, so stay tuned for that. 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