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The hydro-viscous drive (HVD) has been widely used in fan transmission in vehicles, fans, and scraper conveyors for step-less speed regulating and soft starting. It is an efficient method to save energy and reduce consumption. This study aims to analyze the influencing factors of oil film shear torque accurately.

The shear torque calculation model of double arc oil groove friction pairs was established. The influence of groove structure parameters on shear torque was analyzed. The interaction between viscosity temperature and shear torque was considered. Meanwhile, the equivalent radius was calculated when the rupture of oil film appeared. Finally, the test rig of torque characteristics was set up. The variance of shear torque with the input rotation speed under different oil film thickness, different oil temperature, and different flow rate was seen.

The results show that the shear torque increases with the growth of rotation speed. However, the increase of torque is quite gradual because of the effect of the change of viscosity, which is caused by the rise of temperature. The shear torque increases with the decrease of thickness, the increase of inlet flow rate, and the decrease of inlet oil temperature. Meanwhile, when the feeding flow rate is less than the theoretical, the oil film gets ruptured and the shear torque decreases sharply.

The influence on shear torque during full film shear stage in HVD can be achieved much more accurately through both experimental research and theoretical modeling in which groove parameters, influence of temperature, and oil film rupture are considered. Therefore, the shear torque of HVD can be predicted by theoretical model and experimental research in full film shear stage.

The purpose of this paper is to establish a simplified model of the closed hydrostatic guideway for the rapid analysis of static and dynamic characteristics. Further, the influence of compressibility and dynamic frequency are taken into consideration in the new dynamic model.

The new model is based on the second kind of Lagrange equation. In this model, the closed hydrostatic guideway is supported by 12 pads, and each oil pad is equivalent to a nonlinear spring-damper system. The equivalent spring coefficient and damper coefficient of the oil pad are extracted by the three different equivalent methods. Finally, the validation experiments of step load response and dynamic stiffness are conducted on a hydrostatic guideway.

For solving the step response, the linear spring-damper model and the nonlinear spring-damper Model 1 are better than the nonlinear spring-damper Model 2. The accuracy of the three methods are very high for static stiffness calculation. For the calculation of dynamic stiffness, the nonlinear spring-damper Model 2 is better than the nonlinear spring-damper Model 1. The linear spring-damper model has low precision for dynamic stiffness calculation, especially at high frequency. The accuracy of the new model is validated by experiments.

The equivalent method of nonlinear spring-damper system has higher accuracy. Different equivalent methods should be adopted for different load types. The computational speeds of the new dynamic model with the three methods are much better than finite element method (about ten times).

Quantifiable data produced in a national report by the Environment Agency of England and Wales entitled Water Pollution Incidents in England and Wales 1997 and published by the Stationery Office in 1998, identifies over 3,723 substantiated pollution incidents across England and Wales in 1997. Within the generic sector classed as “Industry” the construction industry was the most frequent polluter responsible for 22 percent of all substantiated water‐related pollution incidents in that sector. The report also identified that a significant number (28 percent) of all substantiated pollution incidents across England and Wales are directly attributable to mineral‐based fuels and oils, many of which are used extensively within the construction industry. This paper seeks to locate the possible causes and effects for some of that oil‐based pollution, discusses the issues and identifies a unique and radical client‐motivated solution within the UK to reduce and mitigate the undesirable impacts upon the environment. Evidence produced by the oil industry shows the enormous amount of one particularly aggressive pollutant – hydraulic oil – which remains annually, unaccounted for. Hydraulic oil is used in most tracked earthmoving machinery; the sort of machinery most closely associated with construction work carried out near to watercourses. Biodegradable hydraulic oil is much more considerate to the environment, but is more expensive and not usually installed in new plant and machinery. The paper argues that on a life cycle basis the use of biodegradable oil is viable and feasible and that there are many external factors that make its usage desirable.

This chapter considers food security in the Kingdom of Saudi Arabia from a global perspective within a water-energy-food nexus framework.

A general water-energy-food nexus framework is used to analyze the interplay of water scarcity, relative energy abundance, and food production and consumption in the Kingdom of Saudi Arabia. We identify crucial considerations from the perspective of high food import dependency based on sourcing food to the Kingdom of Saudi Arabia through food imports and foreign investments.

The Kingdom of Saudi Arabia has introduced major reforms to reduce the use of highly subsidized but very scarce water for domestic feed and food production. However, the country is now more vulnerable to increasing food demand in relation to high, volatile world market prices, particularly for cereals. Despite major reforms in agricultural production, the KSA government faces serious challenges.

Developing strategies to meet the KSA food security objectives is essential. The KSA government should push reform even further and revise its policy regarding forage crops to save scarce water resources. Furthermore, the Kingdom of Saudi Arabia would benefit from a more extensive food security strategy in which food stocks and subsidies are complemented by in-kind and cash transfers.

DEVELOPMENT of a commercialaero‐engine like the Rolls‐Royce Bristol/S.N.E.C.M.A. Olympus 593 turbojet powering the Anglo‐French Concorde supersonic airliner is a continuous process in which four initial phases can be defined:

There is increasing discussion within the communication industry about benchmarking and best practice. The concepts, derived from manufacturing industry, are now being used to compare and analyse communication functions and practices. To a certain extent this has been driven by organisations involved in total quality management or re‐engineering but a number of people are now seeking to use the concepts to improve public relations practice. This paper explores — through three case studies — the extent to which benchmarking and best practice are relevant to communication; benchmarking methodologies; and, the extent to which current benchmarking practices are genuinely innovative. The case studies explore best practice in environmental reporting through comparisons of international reporting practices and international reporting guidelines and shareholder communications and ethical codes.