Assessment of environmental and economic efficiency of iron ore breaking technology using emulsion explosives

Methodology for calculating parameters of drilling and blasting operations for stoping works in mines of Kryvorozhskiy basin and PJSC «Zaporizhskiy iron-ore plant» has been improved with the help of established coefficient of relative capacity for the Ukrainit-PM-2B explosive. A new technology of stoping operations for ore breaking by square-chamber methods at deposit thickness more than 5 m is proposed which assumes usage of emulsion explosives and downward drilling of production hole rings in the direction of underlying drilling horizons. Ecological and economical effectiveness of the proposed ore breaking technology implemented in the extraction chambers was estimated. Regularities of harmful substances hazard index changing were established depending on distance to the emission point when trotyl-contained and emulsion explosives are used. Implementation of the proposed technology allows decreasing prime-cost of 1 ton of ore by 15 % per one extraction unit

ВыБОР МЕСТ УСТАНОВКИ БАТАРЕЙ КОНДЕНСАТОРОВ ЗАДАННОЙ МОЩНОСТИ И РЕКОНФИГУРАЦИЯ В РАСПРЕДЕЛИТЕЛЬНыХ СЕТЯХ С ПОМОЩЬЮ СЕЛЕКТИВНОГО МЕТОДА РОЯ ЧАСТИЦ

Запропоновано селективний метод рою частинок для вирішення проблем оптимізації структури і ре- жимів розподільних мереж. Метод був використаний для зниження втрат електроенергії і поліпшення якості напруги шляхом сумісної оптимізації конфігурації розподільної мережі та місць встановлення і потужності батарей конденсаторів. На прикладі двох тестових схем показана ефективність запропо- нованого методу.Предложен селективный метод роя частиц для решения проблем оптимизации структуры и режимов распределительных сетей. Метод был использован для снижения потерь электроэнергии и улучшения качества напряжения путем совместной оптимизации конфигурации распределительной сети и мест установки и мощности батарей конденсаторов. На примере двух тестовых схем показана эффектив- ность предлагаемого метода

Prognostic factors for outcomes after whole-brain irradiation of brain metastases from relatively radioresistant tumors: a retrospective analysis

<p>Abstract</p> <p>Background</p> <p>This study investigated potential prognostic factors in patients treated with whole-brain irradiation (WBI) alone for brain metastases from relatively radioresistant tumors such as malignant melanoma, renal cell carcinoma, and colorectal cancer. Additionally, a potential benefit from escalating the radiation dose was investigated.</p> <p>Methods</p> <p>Data from 220 patients were retrospectively analyzed for overall survival and local control. Nine potential prognostic factors were evaluated: tumor type, WBI schedule, age, gender, Karnofsky performance score, number of brain metastases, extracerebral metastases, interval from diagnosis of cancer to WBI, and recursive partitioning analysis (RPA) class.</p> <p>Results</p> <p>Survival rates at 6 and 12 months were 32% and 19%, respectively. In the multivariate analysis, WBI doses >30 Gy (p = 0.038), KPS ≥70 (p < 0.001), only 1-3 brain metastases (p = 0.007), no extracerebral metastases (p < 0.001), and RPA class 1 (p < 0.001) were associated with improved survival. Local control rates at 6 and 12 months were 37% and 15%, respectively. In the multivariate analyses, KPS ≥70 (p < 0.001), only 1-3 brain metastases (p < 0.001), and RPA class 1 (p < 0.001) were associated with improved local control. In RPA class 3 patients, survival rates at 6 months were 10% (35 of 39 patients) after 10 × 3 Gy and 9% (2 of 23 patients) after greater doses, respectively (p = 0.98).</p> <p>Conclusions</p> <p>Improved outcomes were associated with WBI doses >30 Gy, better performance status, fewer brain metastases, lack of extracerebral metastases, and lower RPA class. Patients receiving WBI alone appear to benefit from WBI doses >30 Gy. However, such a benefit is limited to RPA class 1 or 2 patients.</p

Tectono-metamorphic controls on Archaean gold mineralization in the Barberton greenstone belt, South Africa: an example from the New Consort Gold Mine.

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Extensional detachment faulting and core-complex formation in the southern Barberton granite-greenstone terrain, South Africa: Evidence for a 3.2 Ga orogenic collapse

The Barberton greenstone belt in South Africa is an Early- to Mid-Archaean, very low-grade metamorphic supracrustal belt that is bordered in the south by a mid- to lower crustal gneiss terrain. Detailed mapping of the contacts between the supracrustal and gneiss domains along the southern margin of the greenstone belt shows that the supracrustal rocks are separated from the high-grade metamorphic gneiss terrain by an extensional detachment that is situated at and close to the base of the belt. The extensional detachment is approximately 1-km wide and its location corresponds with the heterogeneous, mélange-like rocks of the Theespruit Formation. Within the detachment zone, two main strain regimes can be distinguished. Amphibolite-facies rocks at and below the granite-greenstone contacts are characterized by rodded gneisses and strongly lineated amphibolite-facies mylonites. The bulk constrictional deformation at these lower structural levels records, in a subhorizontal orientation, the vertical shortening and horizontal, NE-SW directed stretching of the mid-crustal rocks. The prolate, coaxial fabrics are overprinted by greenschist-facies mylonites at higher structural levels that cut progressively deeper into the underlying high-grade basement rocks. These mylonites have developed during non-coaxial strain and kinematic indicators consistently point to a top-to-the-NE sense of movement of the greenstone sequence with respect to the lower structural levels. This relationship between bulk coaxial NE-SW stretching of mid-crustal basement rocks and non-coaxial, top-to-the-NE shearing along retrograde mylonites at upper crustal levels is consistent with an extensional orogenic collapse of the belt and the concomittant exhumation of deeper crustal levels. The exhumation was initiated under amphibolite-facies conditions at depths of approximately 18 km. The extensional collapse is coeval with or shortly follows the main D2 collisional event in the Barberton greenstone belt at ca. 3230-3220 Ma. Voluminous plutonism at ca. 3225 Ma along the northern margin of the belt is possibly related to the orogenic collapse and associated decompression melting of lower crustal rocks. The extensional collapse coincides with the onset of the coarse-clastic Moodies Group sedimentation which suggests that the small, isolated Moodies basins formed as supradetachment basins in the collapsing hanging wall of the detachment. The steepening of lithologies and fabrics to their present-day vertical attitudes is ascribed to a late-stage solid-state diapiric component of the exhumed hot and buoyant basement gneisses that underlie the relatively cool and dense mafic and ultramafic supracrustal succession. © 2003 Elsevier B.V. All rights reserved.Revie

Contrasting source components of clastic metasedimentary rocks in the lowermost Formations of the Barberton greenstone belt.

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