BACKGROUND We studied respirophasic variation in carotid artery blood flow peak velocity (ΔVpeak-CA) measured by pulsed wave Doppler ultrasound as a predictor of fluid responsiveness in mechanically ventilated patients with coronary artery disease. METHODS Forty patients undergoing elective coronary artery bypass surgery were enrolled. Subjects were classified as responders if stroke volume i...


 In recent years, experimental and numerical researches on the effect of blasting pressure stability existing tunnels was widely obtained. However, during excavation a new tunnel or expansion old an has disadvantages still unclear. Some were carried out to study relationship observed Peak Particle Velocity (PPV) lining areas along direction, due either lack in situ test data difficulty co...

In recent decades, the effects of blast loads on existing structures have gained considerable attention due to increase in threat from various activities. Site-specific empirical relationships for calculation blast-induced vibration parameters like Peak Particle Velocity (PPV), Acceleration (PPA), and Displacement (PPD) are commonly used estimation impact blasting an adjacent tunnel. However, th...

like most limestone mines, which produce the raw materials required for cement companies, the transportation cost of the raw materials used in the shahrood cement company is high. it has been tried to build the crushing and grinding plant close to the mine as much as possible. on the other hand, blasting has harmful effects, and the impacts of blast-induced damages on the sensitive machinery, e...

The present paper mainly with deals the prediction of safe charge of explosive used per delay (Qmax) using artificial neural network (ANN) incorporating peak particle velocity (PPV) and distance between blast face to monitoring point (D). 120 blast vibration data sets were monitored at different vulnerable and strategic locations in and around a major coal producing opencast coal mines in India...

Blasting is an essential part of any mining or civil engineering project along with all the benefits that it brings, such as cost and time effectiveness, safety. Still, there are a few downsides to blasting. Ground oscillation velocity most significant impact blasting has been studied broadly. However, not measured values should be used for PPV (peak particle velocity) predictor model developme...

Abstract Measuring the blast-induced ground vibration at blasting sites is very important, to plan and avoid adverse effects of in terms peak particle velocity (PPV). However, measurement PPV often requires time, cost, logistic commitment, which may not be economical for small-scale mining operations. This has prompted development numerous regression equations literature estimate from a relativ...

The general transmissivity law of ground vibrations was studied, and a user-friendly methodology for determining the behavior generated in any rock mass is proposed. study based on single blast trench excavation, analyzing vibration components recorded from two fixed locations. attenuation main variables according to legal requirements, frequency peak particle velocity (PPV), are defined with t...

This research examines the feasibility of hybridizing boosted Chi-Squared Automatic Interaction Detection (CHAID) with different kernels support vector machine (SVM) techniques for prediction peak particle velocity (PPV) induced by quarry blasting. To achieve this objective, a boosting-CHAID technique was applied to big experimental database comprising six input variables. The identified four p...

BACKGROUND Dynamic variables are accurate predictors of fluid responsiveness in adults undergoing mechanical ventilation. They can be determined using respiratory variation in aortic flow peak velocity (▵Vpeak), arterial pulse pressure [▵PP and pulse pressure variation (PPV)], or plethysmographic waveform amplitude [▵POP and pleth variability index (PVI)]. These indices have not been validated ...