Self-similar shock solutions in spherically symmetric polytropic gas flows are constructed and analyzed in contexts of proto-star formation processes. Among other possible solutions, we model a similarity shock across the sonic critical curve with an inner free-fall core collapse and a simultaneous outer expansion of the extended envelope; the separation or stagnation surface between these two ...

Sarvak formation, with the middle cretaceous (Cenomanian) age, is one of the stratigraphic units of the Bangestan group in the southern Iran. The carbonate rocks of this formation form the reservoir rock in the study field. Generally, Sarvak formation is subdivided into three members including Mishrif, Khatiyah, and Maddud in the Persian Gulf, and the average thickness of the reservoir unit (i....

the estimation of velocity distribution plays a major role in the hydrodynamics of vegetated streams or rivers of extensive natural floodplains. the velocity profile in vegetated channels can be divided into three zones: uniform zone which is close to bed with uniform velocity distribution, logarithmic zone which involves the main channel with no vegetive cover and the transition zone that is a...

A mixture solidification model is employed to study the interaction between the melt flow and the growing mushy zone. The goal is to address the importance of considering the melt flow and flow pattern (laminar or turbulent) in the growing mushy zone. A simple 2D benchmark with parallel flow passing by/through a vertically growing mushy zone is considered. Parameter studies with different veloc...

SUMMARY This is the second part of the numerical investigation on a low emissions staged turbine combustor (STC) using a modified version of the KIVA-II code. The main focus of this study is the numerical analysis of the reacting fluid flow and heat transfer inside the quick-quench/lean-combustion (QQ/LC) zones. In the QQ zone, cool dilution air was injected into the hot mixture through eight 4...

OBJECTIVES To predict bladder outlet obstruction with parameters of non-invasive investigations for patients with symptomatic benign prostatic hyperplasia. PATIENTS AND METHODS A sample of 122 men with moderate to severe lower urinary tract symptoms suggestive of benign prostatic hyperplasia was selected. Transrectal prostate ultrasound, free flow measurement, and transabdominal ultrasound fo...

the occurrence of dust storms and their sources in the southern and central parts of iran during the period of 2002 to 2009 was investigated. for this purpose, the meteorological and synoptic data, data from the middle and upper atmosphere, and wind flow tracking model were used. dust storms and nddi were traced using satellite imagery from fasa, shiraz, and bushehr stations. analysis of the gr...

We present an experimental study investigating the transition zone between a liquid-like unyielded region and a solid-like yielded region in a yield-stress fluid. The configuration consists of a rectangular closed-channel flow disturbed by the presence of a step. Upstream of the step, a solid-liquid interface between a dead zone and a flow zone appears. In this study, we use a model fluid, name...

Interspecific hybridization may enhance the capacity of populations to adapt to changing environments, and has practical implications for reforestation. We use genome-wide estimates of admixture and phenotypic traits for trees in a common garden to examine the extent and direction of gene flow across a Picea hybrid zone, testing assumptions of the bounded hybrid superiority and tension zone mod...

Lateral surface/subsurface flow and their connectivity play a significant role in redistributing soil water, which has a direct effect on biological, chemical, and geomorphological processes in the root zone (~1m). However, most of the land surface models neglect the horizontal exchanges of water at the grid or subgrid scales, focusing only on the vertical exchanges of water as one-dimensional ...