Mine roof fall characteristics of 250 falls in 5 different room-and-pillar coal mines, located in Pike, Martin, and Floyd counties, Kentucky, were investigated to determine the relationship of selected parameters associated with roof failure and the assumed condition of the mine roof before failure. The selected parameters used in the study included: presence of cracks and water before the occu...

This paper presents the analytical solution of groundwater response to tidal fluctuation in a coastal multilayer aquifer system consisting of a leaky confined aquifer, a semipermeable layer, and an unconfined aquifer. The semipermeable layer, or the roof of the leaky confined aquifer, extends under the sea. Comparisons are made with solutions derived previously, which considered only a single a...

This paper presents the engineering geological properties and roof control tecnology for a thick coal seam fully-mechanized face mining with hard roof conditions (THC) at the Jinhuagong Coal Mine (JCM), northwest China. The effective support working resistance and appropriate roof control technology are two critical factors for safe and productive mining in the THC. The load-estimate-method (LO...

The Sierra Nevada mountain range consists of a vast array of different geologic features. One of these features is in the form of what are known as roof pendants. Roof pendants span through the central and southern portions of the eastern Sierra Nevada. Representing the geologic history of the Sierra Nevada mountain range in California, metamorphic roof pendants offer a glimpse into the past. T...

The roof plate is an organizing center in the dorsal CNS that controls specification and differentiation of adjacent neurons through secretion of the BMP and WNT signaling molecules. Lmx1a, a member of the LIM-homeodomain (LIM-HD) transcription factor family, is expressed in the roof plate and its progenitors at all axial levels of the CNS and is necessary and sufficient for roof plate formatio...

The paper describes a novel approach for the generation of 3D building models from airborne laserscanner data, which is based on the detection of straight lines in specific 2D projections of the data. First, the main roof ridge directions of a building are determined. Based on these ridge directions, hypotheses on the roof orientation are generated. The whole point cloud is rotated by the roof ...

Photovoltaic (PV) panels get hot in the sun. This decreases the operating efficiency through various means. Several approaches have been proven effective at cooling panels. Green Roofs are thermally cool, outperforming even white roofs over their life. On a hot summer day, a green roof can be 30◦C cooler than a typical roof, potentially improving the efficiency of a photovoltaic (PV) panel by a...

A set of state-of-the-art FE vehicle, restraint system, dummy, and whole body human models was constructed and validated against several sets of quasi-static and dynamic rollover tests. HIII dummy responses during three selected trip-over scenarios were simulated using an FE vehicle model equipped with four different roof stiffness values. It was found that the high dummy head accelerations and...

Perhaps the most significant development in coal mine ground control during the last century was the introduction of roof bolting during the late 1940’s and 1950’s. From an engineering standpoint, roof bolts are inherently more effective than the wood timbers they replaced. Roof bolts promised to dramatically reduce the number of roof fall accidents, which then claimed hundreds of lives each ye...

considering current population rate and ratio of non renewable energies in countries' annual energy diagram which lead to increase of pollutions reeked from and irreparable effects on living environment, there will be an energy and living environment crisis in close future. so there are two main approaches that should be considered in countries' future program: change of construction ...