Nickel and chromium cycles: Stocks and flows project part IV

Nickel and chromium are essential ingredients in alloys increasingly important for energy-efficient, environmentally friendly modern technology. Quantitative assessment of the flows of these metals through the world economy from resource extraction to final disposal informs resource policy, energy planning, environmental science, and waste management. This article summarizes the worldwide technological cycles of nickel and chromium in 2000. Stainless steel is the major use of these metals, but they serve numerous other special needs, as in superalloys for high-temperature service, as plating materials, and in coinage. Because they are used primarily in alloys, novel recycling issues arise as their use becomes more widespread. “... the great New York and St. Louis double track, nickel plated railroad...” — Norwalk, Ohio, Chronicle 10 March 1881 announces arrival of surveyors for the future Nickel Plate Railway “Later [1911] I formed an alloy of Iron and Chromium, which showed remarkable resistance to rust and tarnish ... [It was] rediscovered by an Englishman named Brearley, in 1914.” —Elwood Haynes to Stephen F. Roberts, 17 January 1925     

广州市西村水厂生物预处理试验研究

介绍广州市西村水厂生物预处理试验研究,探讨用生物预处理工艺处理西村水厂现有原水的效果。试验结果表明生物预处理对改善西村水厂现有水源水质效果显著,"生物预处理 常规处理"后的最终出水的考察项目全部符合《生活饮用水卫生标准》。指出实施生物预处理工艺与西江引水工程相衔接,完全可以保障西村水厂的供水水质。     

Measurement of three-phase transformer derating and reactive power demand under nonlinear loading conditions

The measurement of real and apparent power derating of three-phase transformers is important for transformers feeding nonlinear loads. This paper presents a new digital data-acquisition method for measuring derating and reactive power demand of three-phase transformers under full or partial load conditions. The accuracy requirements of the instruments employed (potential, current transformers, shunts, voltage dividers, optocouplers volt- and current meters) are addressed. Application examples demonstrate the usefulness of this new digital data-acquisition method.     

Geotechnical properties of the soft soil in Guangzhou College City

The paper describes some geotechnical properties of the soft soils in Guangzhou College City, China, which are difficult to both sample and test. Laboratory and in situ tests were carried out to assess the physical and mechanical indices of the soils. The data were statistically analyzed and linear regression undertaken such that equations could be developed by which the geotechnical properties of the soft soils can be predicted. The statistical validity of the degree of correlation confirmed that using these equations, the mechanical indices can be estimated from physical indices determined by routine testing.      

Algorithms for multiprocessor scheduling with two job lengths and allocation restrictions

A variant of the High Multiplicity Multiprocessor Scheduling Problem with C job lengths is considered, in which jobs can be processed only by machines not greater than a given index. When C=2, polynomial algorithms are proposed, for the feasibility version of the problem and for maximizing the number of scheduled jobs.     

Refactoring and converting a TTCN-2 test suite

When deploying TTCN-3 at Nokia, we converted two TTCN-2 test systems to TTCN-3. We explain to which extend we have been able to do the conversion automatically. The conversion tool used provided a syntactically and semantically correct conversion of the TTCN-2 code. We define some improvements made on the tool to increase readability and maintainability of the resulting code. We cover aspects of converting also the non-TTCN-2 parts and describe the experiences we made as a set of lessons learnt.