In the process of mining graphite mine, rock mass is often subjected to dynamic loads such as blasting or mechanical crushing, which involves dynamic responses of different strain rates, and blasting and crushing effect are affected by the rock dynamic properties and damage specials. The dynamic response characteristics and damage rule of graphite ore rock under different strain rates are very important but rarely studied in the past. To study these issues and provide support for graphite ore rock mining, the dynamic compression tests of graphite ore rock under five kinds of impact pressures were designed and carried out by using the Split Hopkinson Pressure Bar (SHPB) test system, combining with the high-speed photography system and crushing screening tests.
View Article and Find Full Text PDFMin Metall Explor
January 2021
There have been many improvements and advancements in the application of neural networks in the mining industry. In this study, two advanced deep learning neural networks called recurrent neural network (RNN) and autoregressive integrated moving average (ARIMA) were implemented in the simulation and prediction of limestone price variation. The RNN uses long short-term memory layers (LSTM), dropout regularization, activation functions, mean square error (MSE), and the Adam optimizer to simulate the predictions.
View Article and Find Full Text PDFWith extensive perioperative use of dexmedetomidine, there has been rising concern about its side effects, which are most commonly bradycardia and hypotension. However, increased urine output or diuresis is not well recognized with perioperative use of dexmedetomidine. We report a case of intraoperative polyuria induced by dexmedetomidine.
View Article and Find Full Text PDFBACKGROUND In the present study, we aimed to determine the effect of different positive end-expiratory pressure (PEEP) levels on the cross-sectional area (CSA) of the right internal jugular vein (RIJV) and the overlap index between the RIJV and the right common carotid artery (RCCA) in mechanically ventilated patients with laryngeal mask airway (LMA) insertion. MATERIAL AND METHODS A total of 60 patients who were scheduled for elective surgery under general anesthesia with LMA insertion were enrolled. After LMA insertion, the image of RIJV and RCCA were taken after applying 4 different PEEPs in a random order: 0 (P0), 5 (P5), 10 (P10), and 15 (P15) cm H₂O.
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