As excess water is discharged from a high dam, low frequency noise (air pulsation lower than 10 Hz, LFN) is generated and propagated in the surrounding areas, causing environmental hazards such as the vibration of windows and doors and the discomfort of local residents. To study the generation mechanisms and key influencing factors of LFN induced by flood discharge and energy dissipation from a...

abstract weirs are the most common structures for discharge measurement in engineering research. streamline curvature, non hydrostatic pressure distribution on weir and nappe adherence to the weir lead to differences between calculated and measured discharges. thus discharge coefficient, which is the ratio of real and theoretic discharges, is usually less than unity. in circular weirs the press...

A chute is characterized by a steep bed slope associated with torrential flow. This chute flow may be either smooth or stepped. The flow conditions in stepped channels are classified as nappe flow, transition flow and skimming flow. In this paper, hydraulic characteristics of flow regimes on the stepped channels are presented systematically under a wide range of discharge, channel slope and ste...

The stepped channel design have been used since more than 3,000 years. It is understood that low flows behave as successions of free-jets (i.e. nappe flow) while large discharges skim over the pseudo-bottom formed by the step edges. For a range of intermediate flow rates, a transition flow regime takes place. The dominant feature is stagnation on the horizontal step face associated with signifi...

The structural configuration of SW Japan mainly reflects a late Jurassic-early Cretaceous orogeny. The region is divided into an inner belt and an outer belt, on the Japan sea and Pacific ocean sides respectively, by a strike-slip fault, the Median Tectonic Line (MTL). Both consist of a series of stacked nappes. The inner belt is divided into a Jurassic olistostrome known as the Tanba zone and ...

Artificial intelligence is the area of computer science focusing on creating machines that can engage on behaviors that humans consider intelligent. In the past few years, the applications of artificial intelligence methods have attracted the attention of many investigators. Many artificial intelligence methods have been applied in various areas of civil and environmental engineering. The aim o...

Wetting front instability (fingered flow) accelerates solute transport through the unsaturated zone to the groundwater table. Whether fingers widen or dissipate close to the groundwater is unclear. Water flow in a two-dimensional artificial capillary fringe below a dry layer exhibiting fingered flow was investigated. The flow diverged strongly in the wet soil, suggesting that fingers dissipate....

reflect the dewatering of structurally lower levels after nappe emMuscovite and biotite dehydration-melting reactions near the peak placement. If so, then nappe emplacement occurred at T~475°C. of metamorphism played a significant role in the reaction and fluid history of the Rangeley Formation in southwestern New Hampshire, USA. Evidence for in situ melting includes: (1) the consistency among ...