grade control structures are hydraulic structures used to stabilize a river bed. scour downstream of this structure is the main cause of its failure. studies have developed numerous empirical relations for scour depth prediction that designers must choose between to decide the most effective equation for a specific application. this study tested the condition of submerged jets over beds of sedi...

pelecaniformes are large water birds feeding by hunting fish and living usually in the sea and in fresh water. ectoparasitic lice of the genus piagetiella are interesting from an ecological standpoint as they are found in the pouches of pelicans. unlike chewing lice, which live on the body surface of the host, p. titan lives in the oral cavity of white pelicans (pelecanus nocrotalus, l.). this ...

The river delta in The Netherlands consists of interconnected rivers and large water bodies. Structures, such as large sluices and pumps, are available to control the local water levels and flows. The national water board is responsible for the management of the system. Its main management objectives are: protection against overtopping of dikes due to high river flows and high sea tides, supply...

the main purpose of this research was to analyze agricultural water management problems (awmp) in three contexts of: water source, water conveyance and at the farm level, in zarrindasht county, fars province. the research was carried out based on a survey method with a questionnaire compiled for collection of data. questionnaire's reliability was confirmed through a computation of cronbach...

The U.S. Veterans Health Administration (VHA) may have a very different structure and function from the organizations and practices that provide medical care to most Americans, but those organizations and practices could learn a lot from the VHA's Quality Enhancement Research Initiative (QUERI). There are at least six topics of increasing importance for implementation research where QUERI exper...

The molecular geometry of complex of adenine with 8 water molecules was calculated with Hartree-Fock (HF). The standard 6-31G(d) basis set has been employed. The existence of C-H…O Hydrogen bonds between the water molecules and the hydrophobic part of nucleobase is stablished. We optimized structures and computed interaction energies of all complexes of adenine with water molecules step by step...

the part of precipitation that directly meets the water requirements of a plant, is termed the effective rainfall. effective rainfall estimation methods consist of: direct measurement, empirical methods, and soil-water balance modeling. due to the high costs of measurements and storing devices such as lysimeter, empirical and balance methods are most commonly used to estimate the effective rain...

intra-city natural structures have always had a key role in creating sustainable urban greenspaces. adapting to natural features and relating the intra-city greenspaces to such natural structures as river-valleys, hillsides, lakes and forests, guarantee the endurance, sustainability and longevity of the natural quality of city. this paper looks at intra-city natural structures which have underg...