the osteology of the hyoid and branchial arches in several representatives of eurypterygian fishes were examined. the hyoid arches consist of a single basihyal and urohyal, and the arch on each side consists of a dorsal and a ventral hypohyal, an anterior and posterior ceratohyal, an interhyal, and branchiostegal rays that are borne on the ceratohyals. the branchial arches consist of three sing...

Introduction In the foreword to the Malaysian Guidelines for Operation, Maintenance and Surveillance of Dams (Malaysian Inter-Departmental Committee on Dam Safety 1989), it is stated “The expanding inventory of dams has brought into focus the subject of dam safety”. At the time of the guideline publication, there had been a considerable increase in the inventory of dams with those constructed d...

A survey conducted near a dam-site on the Paraguay-Argentine border showed the area to be highly endemic for Chagas’ disease. It also showed that new housing unsuited to the disease vector’s prol$eration did not eliminate the prob/em, indicating a strong need for health education capable of guiding people away from traditional behavior patterm tending to encourage the vector and cause infection.

abstract spacing between check dams depends on the stream bed slope, effective height of check dams and slope of deposited sediments behind the check dams. the slope of deposited sediments is more important than the other two factors because of complications in the way of its occurrence and its measurement after several years of dam construction. this research presents the effective factors aff...

Large dams degrade the integrity of a wide variety of ecosystems, yet direct downstream effects of dams have received the most attention from ecosystem managers and researchers. We investigated indirect upstream effects of dams resulting from decimation of migratory freshwater shrimp and fish populations in Puerto Rico, USA, in both high- and low-gradient streams. In high-gradient streams above...

Temperature is one of the main loads super-high arch dams. (1) Background: a dam in southwest China was taken as an example this paper and temporal-spatial evolution law temperature analyzed based on monitoring data. (2) Methods: finite element simulation analysis method adopted to invert boundary conditions upstream surface thermal parameters concrete, process long-term operation simulated ana...

Evaluation of the sliding stability concrete dams requires use numerical tools not only able to simulate coupled hydromechanical behavior but also adequately represent foundation discontinuities and specific features dam foundations. The formulation a three-dimensional (3D) small displacement finite element model based on interface elements is presented. In this model, hydraulic simulated assum...

Longitudinal connectivity is a fundamental characteristic of rivers that can be disrupted by natural and anthropogenic processes. Dams are significant disruptions to streams. Over 2,000,000 low-head dams (<7.6 m high) fragment United States rivers. Despite potential adverse impacts of these ubiquitous disturbances, the spatial impacts of low-head dams on geomorphology and ecology are largely un...