This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited.In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit:The benefits of promoting renewable energy are regularly claimed to be energy security, climate change mitigation and job creation. While the first two benefits are generally accepted, the impact of renewable energy on employment is still disputed. This paper presents a discussion of the various factors that influence the analysis of renewable energy and its impact on employment. The advantages and disadvantages of input-output methods and analysis methods are discussed as well as the issues surrounding the measurement of job creation. A critical evaluation of the literature reveals factors that should be considered when completing a study about renewable energy and employment: labour intensity of renewables; cost increases and availability of investments; counting job losses; job quality and skills, model assumptions and sources of information. Analytical studies using extensive surveys were found to be more appropriate for regional studies while input-output methods were better suited to national and international studies.

Some stiffness and damping characteristics are presented for taper-roller bearings with interference fits. The major parameters investigated were preload, temperature, lubricant viscosity, excitation frequency, excitation amplitude, and rotational speed. The prediction, based on a model of the bearings, that stiffness and damping would effectively be independent of oil viscosity was confirmed.

Rolling-element bearings are among the most common components of modern machinery and yet little is known about their characteristics under working and oscillating conditions. Thus, when spindle systems are designed and their dynamic stiffness is important, it is very difficult to find suitable characteristics to use in the modelling. It is the purpose of this paper to indicate why these characteristics are difficult to measure and to discuss the results that are available in the literature. It is also the case that very few models have been developed to represent the stiffness and damping of rolling-element bearings. In the 1980s, some models were developed, but these were in confidential, limited-circulation publications. However, permission has now been given to present these models in the open literature. The principles of a rig are described that allow the stiffness and damping properties of rolling-element bearings to be measured under rotating conditions. A theoretical analysis is presented that allows the characteristics of the rolling contacts to be predicted. In addition, the effect of the necessary joints that arise when using bearings is analysed. A detailed description is given of the rig and its initial calibration and testing. The extensive results obtained are described in parts 2 and 3 of this work.

Some characteristics are presented for taper-roller bearings with a clearance fit. The stiffness and damping in the joints between raceways and housing/shaft are shown to be significant. The other major parameters investigated are preload, temperature, lubricant viscosity, excitation frequency, excitation amplitude, and rotational speed. The relevance of the measured characteristics to the design of spindles with high dynamic stiffness is discussed. Also the significance of radial and tilt characteristics is compared.

There are many industrial sites where open aggregate conical piles exist to store granular materials, like coal, industrial residuals, or other minerals. Usually these storage piles are placed in open areas, making them susceptible to wind erosion, which can create health, environmental, and/or economical concerns. It is common to minimize the dust emission through the placement of windbreaks in the vicinity of the storage piles, which reduces the wind speed in the vicinity of the pile's surface. In this work, some experimental results from a wind tunnel study on the erosion of a conical sand pile, exposed or protected by a fence with porosities of 0, 70, and 83%, are shown. For the sheltered cases, the windbreak was placed at several distances from the pile's leading edge, ranging from H to 4H, where H is the initial height of the non-eroded pile. The evolution of the shape of the sand pile is shown, at different instances in time, and the pile deformation quantified, using a novel experimental setup developed for wind erosion studies. This information might be regarded as a useful dataset for the benchmark of computational models aiming to produce the transient simulation of the aeolian erosion of stockpiles. The CFD results are comprised of the modeling of several experimental scenarios. The computational results for the surface wind velocity show a good correlation with the initial deformation of the pile. Based on the results, the isocontours of (u s /u r ) presented might be regarded as a good basis for the estimation of the pile shear velocity.