Trong mô hình chuẩn về vũ trụ, năng lượng tối hiện chiếm gần 9/10 tổng năng-khối lượng của vũ trụ. Năng lượng tối là dạng năng lượng ở dạng cơ bản có độ lớn (Tác động của nó)gần như bằng 0,sẽ biến thành Năng lượng Hạt = vật chất Hạt khi có điều kiện nhiệt độ, áp suất và tác động thích hợp. | 110 energy a beginner s guide GAS TURBINES cont. Gas turbines have also found a variety of stationary applications they are the preferred choice to power the large centrifugal compressors that push natural gas through pipelines and supply the pressure needed for many chemical and metallurgical processes and they are increasingly used to generate electricity in relatively small decentralized facilities. Technical improvements have lifted the efficiencies of these machines above forty per cent and in combined cycles using the exiting hot gas to heat water for a smaller steam turbine they were the first converters whose efficiency surpassed sixty per cent. Arguments about an imminent peak of global oil production and the coming end of the oil era have become common at the beginning of the twenty-first century but are too often unjustifiably pessimistic. While the chances of discovering new super-giant oil fields have certainly become very low there remains an enormous potential for individually smaller but cumulatively substantial new discoveries in parts of the Middle East Siberia Central Asia Africa and the deeper waters of the Gulf of Mexico. In addition there are huge deposits of non-traditional oil some Canadian tar sands in Alberta Venezuelan heavy oil are already exploited commercially. Consequently global civilization will rely on crude oil for decades to come while continuing to use more natural gas the simplest cleanest and hence in many ways most desirable of all hydrocarbons. The only well-documented use of natural gas in a pre-industrial society was its burning to evaporate brine in landlocked Sichuan in China which began in the early Han dynasty about 200 . . Natural gas is composed mostly of methane with small amounts of ethane propane hydrogen sulfide and nitrogen. It is often mixed with crude oil in the same reservoir. During the early decades of the oil industry when there were no high-pressure long-distance pipelines this so-called associated .
