Vessel-towed acoustic Doppler current profilers (ADCPs) have been widely used to measure velocity profiles. Since the instrument is usually mounted on a catamaran floating on the surface, previous studies have used the water surface as the reference level from which the vertical coordinate for the velocity profile is defined. However, because of the tidal oscillation, the vertical coordinate th...

in this article, finite element method and ale formulation were used to numerically simulate impact of low-velocity specific projectiles with water surface. for the simulation, ls-dyna finite element code was used. material models which were used to express behavior of air and water included null material model. for the projectile, plastic-kinematics material model was applied. mie-gruneisen eq...

This paper investigates the velocity and the trajectory of water particles under surface waves, which propagate at a constant water depth, using particle image velocimetry (PIV). The vector fields and vertical distributions of velocities are presented at several phases in one wave cycle. The third-order Stokes wave theory was employed to express the physical quantities. The PIV technique's abil...

This article is concerned with the infinite depth water wave equation in two space dimensions. We consider this problem expressed in position-velocity potential holomorphic coordinates, and prove that small localized data leads to global solutions. This article is a continuation of authors’ earlier paper [11].

This article is concerned with the incompressible, irrotational infinite depth water wave equation in two space dimensions, without gravity but with surface tension. We consider this problem expressed in position-velocity potential holomorphic coordinates, and prove that small data solutions have at least cubic lifespan while small localized data leads to global solutions.

Scaling is an integral component of ecology and earth science. To date, the ability to determine the importance of air – water gas exchange across large spatial scales is hampered partly by our ability to scale the gas transfer velocity and stream hydraulics. Here we report on a metadata analysis of 563 direct gas tracer release experiments that examines scaling laws for the gas transfer veloci...

the greatest limitations to agricultural development and production in iran are scarcity of water resources, ineffective irrigation scheduling and wasteful water usage. avenues discussed for optimum water use include improving water productivity by improving irrigation scheduling, farm water management and water profitability. the present study evaluated current water use and ways to improve wi...

throughout history dams have been important structures in water storage. to avoid overtopping, damage, and or failure of a dam, adequate spillway is needed to release excess water from upstream floods. researchers found that spillways have to be made nonlinear in order to reach an economic structure with high performance. a piano key weir is one of the best solutions. piano key weirs are the mo...

The aim of this study was to determine the influence of environmental parameters onthe abundance of monkey goby Neogobius pallasi. A total of 526 and 163 individuals ofmonkey goby specimens were caught by electro-shocker in the Kaboodval and Shirabad Streams, respectively. The ranges of total length of the specimens in Kaboodval and Shirabad Streams were respectively 22-137.55 mm and 32.64-137....