Paul W. Bauer is an economist at the Federal Reserve Bank of Cleveland, Allen N. Berger is a senior economist at the Board of Governors of the Federal Reserve System, and David B. Humphrey is a professor of finance at Florida State University. The authors would like to thank Knox Love11 and James Thomson for helpful comments, and Alex Wolman and Fadi Alameddine for outstanding research assistance.

The environment of confined spaces such as tunnels and coal mines is complex changeable. When the wireless signal propagates in it, it will be affected by reflection diffraction shaft wall, which puts forward higher requirements for radiation beam mine antenna. In this paper, corrugated horn antenna model selected to design a whose pattern almost equal Gaussian beam. Starting from expression be...

in all over the world, mining is considered as a high-risk activity that is pregnant with serious disasters not only for miners, engineers, and other people into it, but also for people who live near the mines. in this article, our main purpose is to examine some major mine disasters and safety in mines and the case study is a coal mine in turkey. safety in mines is one of the most important is...

This paper describes the experimental study of the shaft oil feed mechanism of a rotary compressor. The oil contained in the shaft in which an oil pump is inserted is fed to the respective sliding surfaces of the subbearing section, eccentric section and main bearing section of the shaft by centrifugal force of shaft rotation. The oil feed pressure of shaft rotation is approximately 0.1 kg/cm2 ...

In the context of open-pit mine planning, uncertainties including commodity price would significantly affect the technical and financial aspects of mining projects. A mine planning that takes place regardless of the uncertainty in price just develops an optimized plan at the starting time of the mining operation. Given the price change over the life of mine, which is quite certain, optimality o...

Abstract Recent months have highlighted the progressing energy crisis across Europe in connection with severe sanctions imposed on import of hydrocarbons and coal from Russia. This is particularly visible Poland, where over 40% electricity generated coal, while individual households it primary source heat. situation puts already enigmatic plans shutting down mining Poland into question. Therefo...

A daunting mine disaster took place in 13 May 2014 at Soma and 301 men lost their lives. Brief information about the Eynez coal mine and some of the inherent characteristics of the field in terms of their effects on mining are presented. This paper basically concentrates on the factors that played an important role in the occurrence of this disaster. Progress of mine fire, firefighting, and res...

Background: Femoral shaft fractures are an incapacitating pediatric injury accounting for 1.6% of all pediatric bonyinjuries. Management of these fractures is largely directed by age, fracture pattern, associated injuries, built of the childand socioeconomic status of the family. We retrospectively evaluated the use of elastic stable intramedullary nail (ESIN)in surgical management of femoral s...

The objective of the drive shaft is to connect with the transmission shaft with the help of universal joint whose axis intersects and the rotation of one shaft about its own axis results in rotation of other shaft about its axis. Shafts must be exceptionally tough and light to improve the overall performance of the vehicle. Automobile industries are exploring composite materials in order to obt...