How can carbon sequestration minimise the greenhouse effect?
It could if we knew how to do it in a way which was feasible, economic and ecologically sound. Unfortunately we don’t. So far most experiments have involved pumping carbon dioxide down wells in order to extract more fossil fuels (a bit of a double edged sword that idea). Otherwise the ideas have been either unsound (leaky) or uneconomic.
Nuclear power generation has been very controversial.?
Nuclear power generation has been very controversial. Cite the advantages of using nuclear power plants. Research the use of nuclear power for electricity production in the rest of the worl. Compare this to the situation in the USA. Based on what you learn in your research, predict whether nuclear power will made a "comeback" in the USA.
Why do water companies still uses dams to store treated water and contends with high loss due to evaporation when you can replenish groundwater aquifers?
First; treated water is not stored in reservoirs contained by dams. Second; fresh water contained in reservoirs by a dam is necessary for very large supplies (high volumes) of water. Ground water aquifers (well water) are not sufficient for providing large volumes of water to large communities. Even the most prolific aquifer will not supply enough water for a large community. As an example: a small city with 25,000 people may use aquifers (wells) to supply approximately 3 million gallons per day. A city the size of NYC needs over 1 billion gallons per day. A smaller city such as Cleveland, Ohio needs approximately 300 million gallons per day to supply the city and 56 million suburban communities around it.There is a newer technology that is called collector wells that have horizontal collectors in an aquifer that can deliver much larger volumes of water than traditional wells, but they have significant restrictions and are often impractical and very expensive.
Why do we construct buildings above the ground?
Following are reason's of doing so--:as we go downward lateral earth pressure goes on increasing, this will accompanied by weight of above floor then we will have to construct huge sections of building parts to bear load/pressure.hence additional expense will come due to increased soil pressure downward and thus in providing support to it to continue construction process.fluctuation in water table will be another challenge to be faced by engineers and if soil conditions are worse then work really can turn out to be in great un-economy because either we have to do corresponding stabilizing measure. after digging below some depth water will cause hindrance in construction and even if we succeeded in construction we will have to make all joins and exposed surface completely water tight.natural ventilation will be another problem, so only option left is artificial ventilation,same will happen to natural lightening. we can provide both these by non-renewable energy resource (fossil-fuel) but building will no longer be energy efficient.earthquake will cause great damage to entire building since complete building is in direct contact of ground. extra cost will be added to construction due to additional provisional of reinforcement to this earth sheltering structure.excavation will cost a lot of entire project and even more if rock strata is present just below ground level.experienced engineer, skilled mason, labor will be required in comparison to building constructed above ground level.
How do I avoid cracks on concrete?
Hi,I will tell you how cracks appear and what is the best solution for that.cracks in concrete is the biggest headache for a civil engineer .concrete is made up up of mix of cement,sand and aggregates and water.Both mix proportions and water cement ratio plays very important role in strength of concrete. So i will briefly explain you.What is Concrete :Concrete is a building material which made from mixture of cement , sand ,crush or gravel and water. and we poured this mixture in the form work which can give us the different shapes of element like stone which is too mush strong.Why Concrete Cracks :1: Excess of water in concrete2: Improper Compaction of concrete3: Rapid drying of concrete4: Temperature Variation1: Excess of water in concreteConcrete does not required much water to get maximum strength . we required limit water in concrete to achieve the maximum strength of concrete. when we increase the water in concrete so it can lose the strength , so therefore concrete can crack. water is just reducing in concrete to make workabality of concrete . so increasing of water can reduce the strength of concrete.2: Improper Compaction of concretebefore placing concrete we have to proper compact the soil. and after that when we placed concrete so concrete should be compacted properly . when the concrete is not compacted so after that concrete gets start to crack after some time of placing of concrete. Because when we don’t compact the concrete so its also reduce the strength.3: Rapid drying of concretewhen concrete rapid drying so its also danger for concrete , Because the rapid drying of concrete is the possibility of cracking. Because there are chemical reaction in concrete its why that concrete change from liquid or plastic to solid form so its required the water. So the hydration process starting in the concrete due to cement presence for weeks after pouring concrete.4: Temperature VariationCracks in concrete is also depend on the temperature, Because the temperature is high at noon time and at after noon time the temperature is reducing. Due to this expansion concrete gets started cracking.Thank YouIf it helped then upvote. This keeps me motivated to write even more.Check the packages for house construction here.
Why is a cellar safe during a tornado?
We were staying with some relatives in tornado alley this weekend, and they had a cellar (small underground room). My aunt mentioned that the cellar saved her life during a tornado a year or so back. How? Why would an underground room be safe? Wouldn't that create a wind tunnel, if say the doors were pulled open? (a tornado can pick up a car, I don't think some iron doors would stop it). Also, why would lying in a ditch be safe? Wouldn't it just...pluck you up?