the system dynamics technique is an object-oriented approach that studies and manages complex feedback systems. its merits include the friendly and easy development and improvement of a model. it is also used as a decision tool for engineering problems. in this paper, the system dynamics technique was used to simulate the performance of a subsurface drainage system in an unsteady state. the mod...

Accelerated erosion in the form of landslides can be an undesirable consequence of clearcut logging on steep slopes. Forest managers need a method of predicting the risk of such erosion. Data collected after logging in a granitic area of northwestern California were used to develop a predictive equation. A linear discriminant function was developed that correctly classified almost 90% of the da...

global warming, as a consequence of greenhouse gases accumulation, has exerted significant impacts on biosphere. methane, a product of reduction processes of organic carbon in anaerobic conditions, is mainly emitted from paddy fields. the aim followed in this research is to evaluate the impact of midseason drainage on methane emission from paddy fields. the research was conducted with three tre...

OBJECTIVE We believed that intercostal catheters were often inserted too far into the thoracic cavity in neonatal patients. The aim of this study was to determine the average distance from the catheter tip to the midline, of intercostal catheters inserted in our neonatal unit and the incidence of catheters that were inserted too far into the thoracic cavity. METHODS During a two year period w...

background: complaining of tearing was found in some of our patients after phacoemulsification surgery for senile cataract. secondary acquired lacrimal drainage obstruction has been proposed to happen due to different causes. this study was performed at feiz hospital in isfahan, iran from september to december of 2004 to evaluate the effects of phacoemulsification surgery on tear drainage in ey...

In view of the high gas pressure and low permeability deep coal seam, it is difficult to control gas, which affects safety production mine. The technical scheme hydraulic fracturing improve seam put forward, drainage technology used emission seam. effect under different water pressure, gradient times, in situ stress analyzed by using 3DEC (3-Dimensional Distinct Element Code) discrete element s...

Acid Mine Drainage (AMD) poses a severe pollution problem attributed to current and past mining activities. Low pH, high concentrations of sulphates and various heavy metals makes AMD treatment a major concern because of possible deleterious effects of the effluent on the surroundings. Treatment methods to address AMD focus on neutralizing, stabilizing and removing problem pollutants through va...

Drainage tube migration after surgical procedures is a rare incidence and in the majority of cases without any significant complications. However, a few cases of intestinal obstruction or perforation have been reported. The most common site of a dislodged tube is the duodenum. Here we present a case of perforation of the sigmoid colon associated with drainage tube migration. A 55 years old male...

Martian terrains are represented as a series of drainage basins, regardless of the historical presence or absence of actual fluid flow. A statistical analysis of each drainage network, computationally extracted from an underlying topography based on the MOLA data, yields a network descriptor, a compact, numerical characterization of a network. These descriptors are used to compare different mar...