Transmission alternatives for offshore electrical power

The oceans represent a huge energy reservoir. Although today all of the marine power projects are very near from the shore and they are rated at low power, the huge potential of the seas may in a not very distant future bring marine power further into the sea. Also offshore oil and gas exploration is moving into deeper waters and at longer distances from land. New carbon sequestration projects under the seabed are on the way which require a vast amount of electric power consumption. The substitution of offshore power generators by power provided from the grid may have environmental benefits, but the deployment of offshore transmission of bulk electrical power to or from offshore platforms to the electrical grid onshore is a mayor challenge. The main objective of this paper is to focus on trends that can lead to a feasible transmission system in offshore energy systems far from land, and to introduce the technological alternatives which could help to reach that goal. The paper describes the main alternatives and the technical and economical aspects of the transmission of electrical power offshore.     

三步提升内存性能

内存作为处理器和硬盘之间的数据传输工具,很多时候起到的是一种桥梁作用。如果桥梁经常堵塞就会严重影响交通,同理内存设置及优化不当,也会严重影响系统的性能。下面就为大家介绍简单的内存优化方法,三步即可轻松提升系统性能。     

Pulmonary epidermoid carcinoma in a 22-year-old patient with multiple cutaneous metastasis]

The authors present one clinical case of lung epidermoid carcinoma with several concurrent features which are uncommon in relation to this type of neoplasia. Consequently, the age of the patient (22), the lack of known risk factors, the histologic type (little differentiated squamous) and an aggressive biologic behaviour of the tumour, preceded of multiple cutaneous metastasis, are circumstances that make this clinical case exceptional. The more significative aspects present at lung carcinoma included in this age group respect to others are analyzed.     

Calcination of phosphate in impinging streams. Part II. Phosphates with high organic matter and with pulverized coal

Calcination of a high organic matter phosphate and a phosphate containing pulverized coal up to 10 wt % was performed successfully in an impinging stream calciner. The results re-established previous conclusions that the present calciner is a useful device. A simplified model has been developed for exploring the effect of various operating parameters on the concentration of phosphate particles at the impingement plane of the streams. It also assisted us in explaining the effect of the phosphate flow rate on the efficiency of calcination. It was established that the calcination rate of phosphate is governed by the internal resistance of the particle to the heat transfer, which was consistent with previous results.