Investigation and Selection of the Suitable Method in Providing Soil-Water Surface Erosion Map

2009 ◽  
Author(s):  
Ali Mohammadi Torkashvand ◽  
M. Hamidi Tabar
Keyword(s):  
Soil Water ◽  
Water Surface ◽  
Suitable Method ◽  
Surface Erosion ◽  
Selection Of

scholarly journals Effects of Turbine Design on Particulate Erosion of Turbine Airfoils

1991 ◽  
Author(s):  
J. H. Wagner ◽  
B. V. Johnson ◽  
D. W. Geiling
Keyword(s):  
Gas Turbines ◽  
Combustion Process ◽  
Particle Diameter ◽  
Surface Erosion ◽  
Erosion Rates ◽  
Trajectory Calculations ◽  
Design Characteristics ◽  
Turbine Airfoils ◽  
Turbine Design ◽  
Selection Of

An analytic study was conducted to determine the effects of turbine design, airfoil shape and material on particulate erosion of turbine airfoils in coal-fueled, direct-fired gas turbines used for electric power generation. First-stage, mean-line airfoil sections were designed for 80 MW output turbines with 3 and 4 stages. Two-dimensional particle trajectory calculations and erosion rate analyses were performed for a range of particle diameters and densities and for ductile and ceramic airfoil materials. Results indicate that the surface erosion rates can vary by a factor of 5 and that erosion on rotating blades is not well correlated with particle diameter. The results quantify the cause/effect turbine design relationships expected and assist in the selection of turbine design characteristics for use downstream of a coal-fueled combustion process.

scholarly journals Numerical Simulation of Soil Water Movement under Subsurface Irrigation

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Xinqiang Qin ◽  
Xianbao Duan ◽  
Lijun Su ◽  
Xiaoqin Shen ◽  
Gang Hu
Keyword(s):  
Soil Water ◽  
Difference Method ◽  
Existence And Uniqueness ◽  
Nonlinear Term ◽  
Numerical Solutions ◽  
Water Movement ◽  
High Dimensional ◽  
Uniqueness Of The Solution ◽  
Selection Of ◽  
Soil Water Movement

By constructing a radial basis function collocation method combined with a difference method, a two-dimensional mathematical model with boundary conditions of soil water movement under irrigation is proposed. The nonlinear term is dealt with a difference method and the equation is solved using an implicit scheme. In addition, the existence and uniqueness of the solution to the soil water movement equation are proven. Numerical results show that the proposed method has high precision and is easier to use than traditional methods. Moreover, the selection of parametercplays an important role in guaranteeing calculation precision. It lays the foundation for the numerical solutions to high-dimensional soil water movement equations.

Host-finding in Trichobilharzia ocellata cercariae: swimming and attachment to the host

Parasitology ◽  
1988 ◽  
Vol 96 (3) ◽  
pp. 493-505 ◽  
Author(s):  
W. Feiler ◽  
W. Haas
Keyword(s):  
Energy Saving ◽  
Temperature Difference ◽  
Water Surface ◽  
Host Finding ◽  
Swimming Behaviour ◽  
Chemical Components ◽  
Maximal Response ◽  
Free Swimming ◽  
Trichobilharzia Ocellata ◽  
Selection Of

SUMMARYThe cercaria of Trichobilharzia ocellata finds and identifies its duck host with a seriesof different behavioural phases. Dispersal and selection of the water surface as microhabitat is achieved by an intermittent swimming behaviour, which is governed by the interplay of passive dropping with forward and backward swimming movements and includes a positive phototactic and a geonegative orientation. Then the cercariae tend to cling to the water surface in an energy-saving resting position. A movement towards the duck feet as the site of entry occurs when shadows evoke forward swimming movements, which are directed away from the source of light, i.e. normally downwards. Forward swimming movements are also stimulated by touch, but only in free-swimming cercariae and not when these are in the resting position. Attachments occur only when a substrate is touched during forward swimming movements. Attachments are stimulated by warm substrates (1 °C temperature difference triggers a nearly maximal response) and by chemical components of duck-foot skin, and the readiness to attach is increased when the forward swimming movement is started by shadow stimuli.

Activity patterns and microhabitat selection of Mallorcan midwife toad (Alytes muletensis) tadpoles in natural torrent pools

1998 ◽  
Vol 19 (2) ◽  
pp. 143-151 ◽  
Author(s):  
Alvaro Roman ◽  
Richard A. Griffiths ◽  
Laurent Schley
Keyword(s):  
Water Surface ◽  
Activity Patterns ◽  
Microhabitat Selection ◽  
Diel Pattern ◽  
Direct Sunlight ◽  
Midwife Toad ◽  
Alytes Muletensis ◽  
Selection Of

AbstractTadpoles of the Mallorcan midwife toad (Alytes muletensis) displayed a clear diel pattern of activity and microhabitat selection in torrent pools in Mallorca. Tadpoles spent much of the day foraging in a non-aggregated fashion in warm shallow areas, and activity peaked at 1700-1900 hr. In mid-afternoon, however, when much of the water surface was in direct sunlight, tadpoles moved away from the shallows and formed aggregations under rock overhangs at the sides of the pool. Both activity and tadpole density in the shallows dropped dramatically after dark, when there was a movement of the population back into deeper water or hiding places.

Surface Erosion of TiO2 subjected to Energetic Oxygen Bombardment

2011 ◽  
Vol 1298 ◽  
Author(s):  
Roger Smith ◽  
Wolfhard Möller
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Atomic Clusters ◽  
Random Selection ◽  
Surface Erosion ◽  
Variable Charge ◽  
Charge Potential ◽  
Dynamics Simulations ◽  
Selection Of ◽  
Oxygen Atoms

ABSTRACTThe effect of energetic oxygen bombardment of the TiO2 rutile {110} surface is studied by means of molecular dynamics simulations using a variable charge potential. A random selection of O atoms and O2 molecules are incident successively and normally onto the surface. At an energy of 5 eV the surface becomes saturated with oxygen until covered with between 1 and 2 monolayers of adatoms. As the fluence further increases Ti atoms are pulled out from the bulk and become surrounded by the O atoms forming well-defined atomic clusters on the surface which then desorb. At bombardment energies of 400 eV, the O atoms penetrate into the bulk and voids form whose surfaces are decorated with oxygen atoms. As the O fluence further increases the surface is sputtered and the voids then intersect the surface forming a very rough topography.

scholarly journals Selection of a suitable model for the prediction of soil water content in north of Iran

2015 ◽  
Vol 13 (1) ◽  
pp. e1202 ◽  
Author(s):  
Leila Esmaeelnejad ◽  
Hassan Ramezanpour ◽  
Javad Seyedmohammadi ◽  
Mahmood Shabanpour
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Suitable Model ◽  
North Of Iran ◽  
Selection Of

scholarly journals CONTAINMENT STRATEGIES FOR MARINE OIL SPILLS IN NEARSHORE WATERS

1985 ◽  
Vol 1985 (1) ◽  
pp. 113-120
Author(s):  
E. H. Owens ◽  
H. H. Roberts ◽  
S. P. Murray ◽  
C. R. Foget
Keyword(s):  
Water Surface ◽  
Oil Spills ◽  
Low Energy ◽  
Physical Parameters ◽  
Tidal Forces ◽  
Nearshore Environments ◽  
Circulation Patterns ◽  
Marine Oil Spills ◽  
Tidal Stage ◽  
Selection Of

ABSTRACT The movement of oil on the water surface is a result of meteorologic and oceanographic processes. Attempts to contain or divert surface oil using booms should factor these processes into the development of deployment tactics. Attempts to deploy booms, disregarding physical and environmental conditions often have met with failure. Differing physical parameters affect water circulation and the movement of oil in the nearshore environments of reef/lagoon and barrier inlet systems; generalized models identify the primary features of each of these two systems for selection of appropriate methods of boom deployment. Circulation patterns across reefs are dominated by wave-driven and tidal-driven forces that carry water across the reef crest into the low energy lagoonal environment. Within the lagoon, tidal and wind stress forces become important factors that drive the circulation systems. Barrier island inlets that form in meso-tidal environments have circulation patterns that are dominated by cyclical tidal forces. In the narrow inlet throats current velocities are frequently too great for booms to contain oil. In this situation diversion of surface oil to areas of low current speeds can be used to protect sensitive lagoonal environments. During the early stages of a flooding tide, current inflow through the inlet is in marginal channels and at this tidal stage oil could be diverted to the shoreline before it enters the inlet throat.

scholarly journals The Influence of Machinery and Equipment Degradation on Their Depreciation

2020 ◽  
pp. 34-50
Author(s):  
Sergey A. Smolyak
Keyword(s):  
Mathematical Modeling ◽  
Linear Model ◽  
Financial Statements ◽  
Fair Value ◽  
Economic Benefits ◽  
Suitable Method ◽  
Operating Costs ◽  
Operational Characteristics ◽  
Numerous Data ◽  
Selection Of

The preparation of financial statements in accordance with IFRS involves the choice of such methods of depreciation for assets that are supposed to reflect most accurately the expected pattern of consumption of future economic benefits from the use of assets. However, in relation to machinery and equipment items this requirement is difficult to implement, since it is not clear how to understand and measure the economic benefits associated with such assets and the pattern of their consumption. In our opinion, the consumption of future economic benefits from the use of an asset is reflected in its fair value, and the depreciation of an asset over a period of time expresses a decrease in the fair value of the asset in that period. Having regard to this position, it is necessary to be be choosing such a depreciation method which affords the best correspondence between the carrying amount of assets and their fair values. We show that the often used linear depreciation method does not satisfy this requirement even for an asset that generates equal annual benefits from year to year. The article is devoted to the selection of the most suitable method of depreciation for machinery and equipment items. In our opinion, it is necessary to take into account the dynamics of their degradation processes (deterioration of operational characteristics). In this regard, we provide numerous data on a decrease in productivity and an increase in operating costs with age for various machinery and equipment categories. The analysis of such data allows us to offer a simple linear model of machine impair­ment/de­gradation, as well as a depreciation method based on it. This method turns out to resemble the sum of the years’ digits method and can be considered as a generalization of such a method. Its applicability to measuring the depreciation of real machinery and equipment items is confirmed by the results of economic and mathematical modeling and experimental estimates.

Methods of Storage Management in the System iCIM 3000

2014 ◽  
Vol 693 ◽  
pp. 38-43
Author(s):  
Miriam Matusova ◽  
Martina Kusa
Keyword(s):  
Modeling And Simulation ◽  
Production Process ◽  
Production System ◽  
Early Identification ◽  
Storage Management ◽  
Suitable Method ◽  
Material Flows ◽  
Different Types ◽  
Selection Of

Storage is one of the most important parts of logistics, which ensures storage of the products at the place and between the place of production and place of usage. Basic role of storage is equilibration and harmonization of differences among differently designed material flows. Selection of a suitable method, which monitors the storage control, is a main decision of the plant representatives. Each method is suitable for a particular materials and different types of production process. Presently, accent is placed at the modeling and simulation of monitored processes in production system. Main reason for simulation is early identification of problems and deficiencies, which could cause significant problems in a real production process.

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