Methodology for determining water losses from irrigation canals

2020 ◽  
pp. 16-18
Author(s):  
Elena Makarycheva
Keyword(s):  
Filtration Rate ◽  
Darcy Law ◽  
Filtration Flow ◽  
Irrigation Canals ◽  
Power Functions ◽  
Two Phase ◽  
Water Losses ◽  
Irrigation Channels ◽  
Unsteady Filtration ◽  
S Curve

The aim of the article is to develop a method for calculating water losses from irrigation channels in determining the permeability of rock in the zone of filtration flow on the basis of the law of infiltration A.N. Kostyakov using the results of studies of free filtration from pits and foundation pits in loess loams. Pressure movement of water in irrigation canals is subject to the laws of two-phase flow, in which – in contrast to the Darcy law for the zone of saturation plays an important role, the volume and its change in time. The filtration rate (VF) increases with increasing rock moisture (θ) along the S-curve, while the pressure gradient (I = dh/dz) decreases. The dependences of these parameters on the pressure are represented by power functions, and their product CDP = VFI does not change in time and can serve as a characteristic of the filtration flow under the channel. When installing paired piezometers near the water chore line in the channel and determining the graph I(t) by the value of the twophase flow constant CDP, it is possible to calculate the filtration rate at a number of times and the water losses during unsteady filtration. Water losses from the channels at equilibrium humidity increases with increasing head according to the formula A.N. Kostyakova, in which the water permeability of rocks is characterized by a steady filtration rate at a head of 1.0 m, and the gradient is the function of pressure. The application of the proposed method of calculating losses in the design of irrigation systems will increase the reliability of the justification of the volume of anti-filtration measures and the forecast of the groundwater level.

scholarly journals Measurement of glomerular filtration rate during flight in a migratory bird using a single bolus injection of FITC-inulin

2013 ◽  
Vol 305 (6) ◽  
pp. F823-F829 ◽  
Author(s):  
Alexander R. Gerson ◽  
Christopher G. Guglielmo
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Exponential Decay ◽  
Water Loss ◽  
Filtration Rate ◽  
High Water ◽  
Migratory Bird ◽  
High Water Content ◽  
Two Phase ◽  
Water Losses

During migration, passerine birds typically complete a series of multi-hour flights, each followed by a period of stopover. During flight, rates of respiratory water loss are high, yet these birds show no signs of dehydration after flights. During stopover, birds become hyperphagic to replenish fat reserves, often consuming food with high water content, such as fruit. Thus migratory birds seem to face an osmoregulatory challenge; they must reduce water losses during flight but retain the ability to excrete large quantities of water while maintaining osmotic balance at stopover. Our goal was to measure glomerular filtration rate (GFR) and fractional water reabsorption (FWR) of a migratory bird in free flight, at rest, and during feeding to assess the role of the kidney in maintaining water balance during migration. We used FITC-inulin and one- and two-phase exponential decay models to first validate a technique and then measure GFR in the Swainson's thrush, a small (∼30 g) songbird. Single-phase exponential decay models and the modified slope intercept method overestimated GFR by 26% compared with two-phase exponential decay models. We found no differences in GFR among fed, resting and flying birds, but FWR was significantly higher in resting and flying birds relative to feeding birds. There was no effect of the rate of respiratory water loss on GFR or FWR in flight. These data support the idea that birds in flight do not dramatically alter GFR but rely on increased FWR to minimize excretory water losses.

scholarly journals Thermo-mechanically coupled ice-sheet response — cold, polythermal, temperate

1993 ◽  
Vol 39 (131) ◽  
pp. 65-86 ◽  
Author(s):  
Kolumban Hutter
Keyword(s):  
Isotropic Body ◽  
Interaction Force ◽  
Moisture Diffusivity ◽  
Darcy Law ◽  
Momentum Balance ◽  
Mathematical Representation ◽  
Heat Conducting ◽  
Two Phase ◽  
Alpine Glacier ◽  
Diffusive Model

AbstractClassical mixture concepts are the appropriate vehicle for describing the dynamics of ice masses containing some water. We review and derive, respectively, the theoretical formulations of cold, polythermal and temperate ice masses, emphasize the peculiarities of the model equations and point to difficulties that were encountered with the proposed models. The focus is both on the adequate physical motivation of the models and the consistency of their mathematical representation. The paper also has a tutorial character.As usual, cold ice is treated as a single-component incompressible heat-conducting viscous fluid, while two different models are presented for temperate ice. When it arises in a polythermal ice mass, the water content is small and a simple diffusive model for the moisture content suffices. This diffusive model is further simplified by taking its appropriate limit, when the moisture diffusivity tends to zero. Temperate ice in a wholly temperate — Alpine — glacier is treated as a two-phase flow problem, i.e. the momentum-balance laws of both constituents ice and water are properly accounted for. Such Darcy-type models are suggested because the water arises in a greater proportion; so its dynamic role can no longer be ignored.The constituent ice is treated as an incompressible non-linearly viscous isotropic body with constitutive properties similar to those of cold ice. The interstitial water is a density-preserving ideal or perfect fluid. The two interact with an interaction force that is proportional to the “porosity” and the seepage velocity. Internal melting that arises will lead to a generalization of the familiar Darcy law.When water is present, the boundary and transition conditions across internal singular surfaces take special, more complicated forms and involve statements on drainage to the base. These conditions are also discussed in detail.

scholarly journals Identification and research of factors affecting the optimal distribution of well flow rates in space

2021 ◽  
Vol 82 (4) ◽  
pp. 204-214
Author(s):  
N. M. Shayakhmetov ◽  
◽  
D. Y. Aizhulov ◽  
Keyword(s):  
Flow Rate ◽  
Filtration Rate ◽  
Darcy Law ◽  
Horizontal Line ◽  
Production Well ◽  
Injection Wells ◽  
Flow Rates ◽  
Factors Affecting ◽  
Central Transition ◽  
Permeability Distribution

The paper discusses and research the factors affecting the filtration rate to reduce stagnant zones in the domain and spreading outside the block under consideration. The main hydrodynamic factors in production by In-Situ Leaching are the distribution of permeability in the reservoir and well flow rates. The study of the factors was carried out on the basis of mathematical models using Darcy Law and Law of Conservation of Mass. Calculation was accomplished on a two-dimensional area with an isotropic and non-uniform permeability distribution to determine the effect of permeability on the leached area. The permeability coefficient was distributed respectively over three zones, in the southern part the permeability was low, in the central transition from low to high, respectively, in the northern part there was a highly permeable zone. Three wells were located in the domain, with the production well in the center of the domain. Injection wells are located symmetrically with respect to a horizontal line passing through the center of the area under consideration. The calculation was carried out for three modes of well flow rates with the ratio of the flow rates of the injection wells 0.5 / 0.5, 0.2 / 0.8, 0.8 / 0.2 relative to the flow rate of the production well. On the basis of comparative analyzes of the obtained results, it is concluded that: at the same flow rates, regardless of the permeability of the zones, the results obtained show that the leaching area in the low-permeability zone is larger in comparison with the high-permeability zone; with an increase in permeability, the shape of the leaching zone tends from round to drop-shaped; with an increase in the flow rate of wells in the radius of the leaching zone, it increases if the flow rate of solutions is much higher than the filtration rate.

scholarly journals Impact of age on the efficacy and safety of peficitinib (ASP015K) for the treatment of rheumatoid arthritis

2021 ◽  
Author(s):  
Yoshiya Tanaka ◽  
Tsutomu Takeuchi ◽  
Daisuke Kato ◽  
Yuichiro Kaneko ◽  
Musashi Fukuda ◽  
...  
Keyword(s):  
Herpes Zoster ◽  
Filtration Rate ◽  
Estimated Glomerular Filtration Rate ◽  
Incidence Rates ◽  
Phase 2 ◽  
Efficacy And Safety ◽  
Phase 3 ◽  
Two Phase ◽  
Related Disease ◽  
Serious Infections

ABSTRACT Objectives To evaluate peficitinib efficacy and safety in Asian patients with rheumatoid arthritis (RA), stratified by age (≥20–<50, ≥50–<65, and ≥65 years). Methods Efficacy data from two Phase 3 studies were analysed. Safety data from one Phase 2, two Phase 3, and one open-label extension study were pooled. Incidence rates per 100 patient-years of adverse events of special interest were calculated, and Cox proportional hazard analysis was conducted. Results 1052 patients received peficitinib for 2 years (median). Peficitinib demonstrated efficacy improvements versus placebo across all age categories. Incidence rates (95% confidence interval) per 100 patient-years for ≥20–<50, ≥50–<65, and ≥65 years were 0.8 (0.4, 1.9), 2.6 (1.8, 3.7), and 4.7 (3.1, 7.0) for serious infections and 3.7 (2.5, 5.4), 6.4 (5.0, 8.2), and 11.2 (8.5, 14.7) for herpes zoster–related disease, respectively. Twenty patients reported malignancies in pooled Phase 2/3 studies. Incidences of serious infections and herpes zoster–related disease increased significantly with age, but there was no association with baseline estimated glomerular filtration rate. Conclusions Peficitinib was efficacious in adult Asian RA patients of all ages. Age, but not estimated glomerular filtration rate, was associated with serious infections and herpes zoster–related disease, demonstrating the importance of an appropriate RA treatment strategy in older patients.

scholarly journals COMPUTER PREDICTION OF INCREASING EFFICIENCY OF WORK OF RAPID MULTILAYER FILTERS FOR ADSORPTION PURIFICATION OF WATER

2020 ◽  
pp. 5-17
Author(s):  
Andrij Bomba ◽  
Jurij Klimjuk
Keyword(s):  
Filtration Rate ◽  
Computer Experiments ◽  
Filtration Flow ◽  
Chemical Adsorption ◽  
Computer Prediction ◽  
Proposed Model ◽  
Adsorption Temperature ◽  
Multilayer Filters ◽  
Physical And Chemical ◽  
Purification Of Water

A model of the adsorption purification of water from impurities in rapid multilayer cone-shaped filters with piecewisehomogeneous porous loads with a constant filtration rate taking into account the removal of part of the heat on the surfaces of division of layers is formulated. The proposed model provides an opportunity to conduct computer experiments to study the change in the concentrations of impurities in the filtration flow and adsorbed on the surface of the adsorbent load during physical and chemical adsorption, temperature, characteristics of piecewise-homogeneous porous loads along the filter height and based on their prediction of optimal adsorbent use and increasing the duration of filters.

Mathematical modelling of carbonate reservoir dissolution and prediction of the controlled hydrochloric acid treatment efficiency

2021 ◽  
pp. 40-46
Author(s):  
R.U. Rabaev ◽  
◽  
A.V. Chibisov ◽  
A.Yu. Kotenev ◽  
M.Yu. Kotenev ◽  
...  
Keyword(s):  
Hydrochloric Acid ◽  
Water Saturation ◽  
Saturation Pressure ◽  
Liquid Solution ◽  
Carbonate Reservoir ◽  
Filtration Flow ◽  
Two Phase ◽  
Filtration Problem ◽  
Acid Effect ◽  
Hydrochloric Acid Treatment

The article presents the theoretical studies results of hydrochloric acid compositions filtration in carbonate collectors porous media saturated with two-phase formation liquid. Solution of filtration problem in the process of carbonate rock leaching with possible regulation of process by hydrocarbon solvents is considered. Numerical algorithm of acid effect on oil-saturated formation is proposed and tested, which allows to determine the following parameters of filtration flow: concentration of hydrochloric acid, distribution of water saturation, pressure and other parameters. A mathematical model of the carbonate collector dissolution process using composite solvents has been developed, which allows predicting technological indicators of acid impact efficiency.

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