نتایج جستجو برای: where some underground man

تعداد نتایج: 2050542  

2017
Gautam Gowrisankaran Charles He Eric A. Lutz Jefferey L. Burgess

Underground coal mining is a dangerous industry where the regulatory state may impose tradeoffs between productivity and safety. We recover the marginal tradeoffs using disasters near a mine as shocks that increase future accident costs. We find that in the second year after a disaster, productivity decreases 11% and accident rates decrease 18-80% for mines in the same state, with some evidence...

2016
Lixin Zhang Zuxing Xuan

where α and β are nonnegative constants. Boundary value problems of ordinary differential equations arise in kinds of different areas of applied mathematics and physics. Many authors have studied two-point, threepoint, multi-point boundary value problems for second-order differential equations extensively, see [–] and the references therein. In recent years, boundary value problems with integ...

2008
Felipe Núñez Sergio Navarro Alberto Aguado Aldo Cipriano

LHD (load-haul-dump) vehicles are used extensively in underground mining operations for ore transporting, primarily in tunnels where access is difficult or dangerous. To ensure underground efficient and safe LHD’s performance, a robust feedback control strategy is needed. A state estimation based MPC scheme was designed for control purposes, and evaluated by simulation. The state estimator was ...

2002
A. D. Bugarski

Achieving substantial reductions in the exposure of underground miners to diesel particulate matter in a number of metal and nonmetal mines in the U.S. depends on the ability of the industry to widely implement advanced diesel emissions control technologies, primarily diesel particulate filter (DPF) systems. Recent field studies showed that diesel particulate filter systems with Cordierite and ...

Journal: :Journal of the Mining and Metallurgical Institute of Japan 1968

2005
Luiz Eduardo Moschini José Eduardo dos Santos José Salatiel Rodrigues Pires

Studies were carried out on the localization and mapping of gas stations in the urban area of São Carlos city, for an environmental diagnosis related to soil, surface water and underground water contamination resulting from likely leaking in fuel underground storage tanks. Considering that a provision of legal restriction makes it possible that most of public areas are not located in gas statio...

Journal: :Transactions of the American Institute of Electrical Engineers 1903

Journal: :Medical History 1982
J. V. Beckett

Carlisle Spedding was principal colliery steward to the Lowther family from about 1730 until his death in 1755. He was responsible for their mining interests, centred on Whitehaven in West Cumberland. His work frequently took him underground, where he was exposed to the inflammable gases found in mines. Ventilation methods were still primitive, and as a result of his exposure Spedding was frequ...

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