asphaltene precipitation and deposition is a serious problem in many iranian fields. the deposited asphaltene results in partial or total blockage of the wellbore and wellstring reducing or completely seizing oil production. this paper studies the asphaltene problem and mitigation methods in wellstring systematically. it presents new approach based on the combination of thermodynamic modeling o...

Abstract The attention of researchers and engineers has been attracted to gabion weirs due their environmental, hydraulic, stability capabilities compared with solid weirs. One the possible problems is partial blockage caused by sedimentation upstream them. This research experiment investigates hydraulic performance broad-crested (GBCWs) an blockage. For this purpose, a total 147 experiments we...

The fact that the nucleated center of the nerve cell is the major source of the macromolecular materials required in the maintenance and function of the whole neuron requires the operation of a steady cellulifugal convection of these supplies into and down the nerve fiber. This proximo-distal traffic has been firmly established, but the mechanisms involved in it are still poorly understood. Bes...

A wake-controlled exterior hood was developed to overcome the negative influence of cross draft on an exterior hood and avoid the operation inconvenience caused by the enclosure of an airflow capture booth. This new type of local exterior hood used the hood suction flow to stabilize the dynamic vortex shedding that was induced when a crossflow passed over a blockage plate, and therefore formed ...

Nasal peak inspiratory flow at altitude. P.W. Barry, N.P. Mason, J-P. Richalet. #ERS Journals Ltd 2002. ABSTRACT: The present study investigated whether there are changes in nasal peak inspiratory flow (NPIF) during hypobaric hypoxia under controlled environmental conditions. During operation Everest III (COMEX 997), eight subjects ascended to a simulated altitude of 8,848 m in a hypobaric cham...

The steady two-dimensional laminar flow past a stationary cylinder is well known to lose stability to a periodic flow at a supercritical Hopf bifurcation point as the flow rate is increased. It is less well known that the critical flow rate at which the instability occurs can be increased by rotating the cylinder about is own axis, and that at a fixed flow rate the vortex street can be eliminat...

Abstract In the present study, we use large-eddy simulation (LES) to investigate how a capping inversion in combination with stable free atmosphere influences flow development and energy extraction large finite wind farm staggered aligned layout. conventionally neutral boundary layer (CNBL), find that gravity waves induce an unfavourable pressure gradient induction region of which contributes u...

Abstract. The objective of this paper was the experimental investigation accumulated induction effect a large offshore wind farm as whole, i.e. global-blockage effect, in relation to atmospheric-stability estimates and operational states. We measured inflow 400 MW German North Sea with scanning long-range Doppler lidar. A methodology reduce statistical variability different lidar scans at compa...

background:   objective: to evaluate the effect of unilateral tubal blockage diagnosed by hsg on cumulative pregnancy rate (cpr) of the stimulated iui cycles.   materials and methods: a cross-sectional analysis was performed between october 2006 and october 2009 in an academic reproductive endocrinology and infertility center. two groups of patients undergoing stimulated iui cycles were compare...