Publications by authors named "D Tuncay"

Bleeder entries are critically important to longwall mining for the moving of supplies, personnel, and the dilution of mine air contaminants. By design, these entries must stay open for many years for ventilation. Standing supports in moderate cover bleeder entries were observed, numerically modeled, and instrumented by researchers at the National Institute for Occupational Safety and Health (NIOSH).

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The Analysis of Retreat Mining Pillar Stability (ARMPS) program was developed by the National Institute for Occupational Safety and Health (NIOSH) to help the United States coal mining industry to design safe retreat room-and-pillar panels. ARMPS calculates the magnitude of the in-situ and mining-induced loads by using geometrical computations and empirical rules. In particular, the program uses the "abutment angle" concept in calculating the magnitude of the abutment load on pillars adjacent to a gob.

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Longwall abutment loads are influenced by several factors, including depth of cover, pillar sizes, panel dimensions, geological setting, mining height, proximity to gob, intersection type, and size of the gob. How does proximity to the gob affect pillar loading and entry condition? Does the gob influence depend on whether the abutment load is a forward, side, or rear loading? Do non-typical bleeder entry systems follow the traditional front and side abutment loading and extent concepts? If not, will an improved understanding of the combined abutment extent warrant a change in pillar design or standing support in bleeder entries? This paper details observations made in the non-typical bleeder entries of a moderate depth longwall panel-specifically, data collected from borehole pressure cells and roof extensometers, observations of the conditions of the entries, and numerical modeling of the bleeder entries during longwall extraction. The primary focus was on the extent and magnitude of the abutment loading experienced due to the extraction of the longwall panels.

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Aim: We evauated the outcome of patients with left ventricular pseudoaneurysms, focusing on those treated surgically.

Methods: Between June 1990 and March 2007, 7 patients underwent surgery because of left ventricular pseudoaneursym following myocardial infarction, at our institution. The median time interval between myocardial infarction and the diagnosis of left ventricular psedoaneursym was 2.

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