Influence of the location of production wells in unconfined groundwater basins: an analysis by numerical simulation

1990 ◽  
Vol 27 (5) ◽  
pp. 657-668 ◽  
Author(s):  
Duke Ophori ◽  
József Tóth
Keyword(s):  
Numerical Simulation ◽  
Steady State ◽  
Groundwater Resources ◽  
The Other ◽  
Recharge Area ◽  
Development Potential ◽  
Discharge Area ◽  
Other Hand ◽  
Well Yield ◽  
Production Wells

Development potential of groundwater resources under continuous production is calculated by numerical simulation for models of unit basins for the plains regions of Alberta, Canada, in order to analyze the relations between the location of water wells on the one hand, and well yield and basin stability, on the other. These relations are expressed in terms of two basin hydrologic parameters, namely the transitional basin yield (TBY) and the sustainable basin yield (SBY). TBY is the net cumulative inflow of water into the system, induced by and during development at a particular site, from an initial to a final steady-state condition. SBY, on the other hand, is the amount of water captured from precipitation due to production at a particular site under the newly established steady-state conditions. TBY is highest for well locations in the discharge area and decreases gradually as the sites are moved toward the recharge area. This is so because more of the naturally discharging, and thus otherwise lost, water is captured by wells located in discharge areas than by wells in recharge areas. On the other hand, SBY is greater if the wells are located in recharge areas than if they are in the discharge areas because an increasing percentage of precipitation is converted to infiltration by production wells as their locations are moved upslope in the basin. From a regional hydrological viewpoint, these are key relations in optimizing the development potential of the groundwater resources in extensive unconfined basins. Precipitation rate, simulated as maximum potential infiltration rate, is assumed to be constant over time. It is shown also that under conditions of restricted rainfall, a recharge-area development results in unstable basin-hydrological conditions sooner than when development takes place in the discharge area. Regional groundwater exploitation should, therefore, be initiated in discharge areas and moved towards recharge regions gradually, and only for compelling reasons. Factors such as precipitation rates and positions of aquifers within a basin affect TBY and SBY to various degrees, thereby influencing the optimal location of well sites in the basin.

TRANSMITTING BIPARTITE AND MULTIPARTITE CORRELATIONS VIA SPIN CHAINS UNDER PHASE DECOHERENCE

2012 ◽  
Vol 10 (06) ◽  
pp. 1250073
Author(s):  
JIAN-FENG AI ◽  
JIAN-SONG ZHANG ◽  
AI-XI CHEN
Keyword(s):  
Steady State ◽  
Anisotropy Parameter ◽  
Quantum Correlations ◽  
Spin Chains ◽  
The Other ◽  
Bipartite Entanglement ◽  
Other Hand ◽  
Long Time ◽  
Phase Decoherence ◽  
The One

We investigate the transfer of bipartite (measured by cocurrence) and multipartite (measured by global discord) quantum correlations though spin chains under phase decoherence. The influence of phase decoherence and anisotropy parameter upon quantum correlations transfer is investigated. On the one hand, in the case of no phase decoherence, there is no steady state quantum correlations between spins. On the other hand, if the phase decoherence is larger than zero, the bipartite quantum correlations can be transferred through a Heisenberg XXX chain for a long time and there is steady state bipartite entanglement. For a Heisenberg XX chain, bipartite entanglement between two spins is destroyed completely after a long time. Multipartite quantum correlations of all spins are more robust than bipartite quantum correlations. Thus, one can store multipartite quantum correlations in spin chains for a long time under phase decoherence.

A Hybrid Semi-empirical Model for Lean Blow-Out Limit Predictions of Aero-engine Combustors

2014 ◽  
Vol 137 (3) ◽  
Author(s):  
Bin Hu ◽  
Yong Huang ◽  
Jianzhong Xu
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Empirical Model ◽  
The Other ◽  
Model Parameters ◽  
Model Parameter ◽  
Other Hand ◽  
Aero Engine ◽  
Semi Empirical

According to the Lefebvre's model and flame volume (FV) concept, an FV model about lean blow-out (LBO) was proposed by authors in early study. On the other hand, due to the model parameter (FV) contained in FV model is obtained based on the experimental data, FV model could only be used in LBO analysis instead of prediction. In view of this, a hybrid FV model is proposed that combines the FV model with numerical simulation in the present study. The model parameters contained in the FV model are all estimated from the simulated nonreacting flows. Comparing with the experimental data for 11 combustors, the maximum and average uncertainties of hybrid FV model are ±16% and ±10%.

NUMERICAL SIMULATION ON THE EXISTENCE OF FLUCTUATION OF INSTANTANEOUS AVAILABILITY

2016 ◽  
Vol 40 (5) ◽  
pp. 703-713 ◽  
Author(s):  
Yang Yi ◽  
Ren Si Chao ◽  
Fan Guimei ◽  
Kang Rui
Keyword(s):  
Numerical Simulation ◽  
Numerical Methods ◽  
Failure Rate ◽  
The Other ◽  
Repairable System ◽  
Repair Rate ◽  
Trapezoidal Formula ◽  
Other Hand ◽  
Increasing Functions

This paper considers the fluctuation of the instantaneous availability by numerical methods for a one-unit repairable system. The choices of the failure rate and repair rate are linear or cubic increasing functions. For the equation of instantaneous availability composing of two convolutions, the following numerical methods are used: the composite Simpson formula and the trapezoidal formula. That is to say, the simulated curves of instantaneous availability under any condition are obtained. Through the simulated results, when the failure rate and repair rate are selected as increasing functions, the extremum of simulated curve exists so fluctuation exists. On the other hand, if parameters of increasing functions become smaller, the fluctuation weakens.

PREANNOUNCED OPTIMAL TAX REFORM

2005 ◽  
Vol 9 (2) ◽  
pp. 150-169 ◽  
Author(s):  
DAVID DOMEIJ ◽  
PAUL KLEIN
Keyword(s):  
Steady State ◽  
Fiscal Policy ◽  
Tax Reform ◽  
The Other ◽  
Welfare Gain ◽  
Welfare Gains ◽  
Optimal Tax ◽  
Other Hand ◽  
Optimal Fiscal Policy ◽  
Implementation Lag

In constitutional democracies, laws take time to be deliberated upon, to be passed, and to be implemented. Motivated by this observation, we study the properties of optimal tax reform when it has to be announced in advance of its implementation. We find that a delay between announcement and implementation has large effects on the optimal fiscal policy during the transition to the new steady state. On the other hand, we find that the welfare gains from optimal tax reform are fairly robust to the introduction of an implementation lag. Increasing the lag from zero to four years reduces the welfare gains by less than a quarter. Moreover, it turns out that this reduction of the welfare gain is mainly due to the delay itself rather than the effect of preannouncement on the character of the optimal tax reform.

scholarly journals A note on dynamical compensation and its relation to parameter identifiability

2017 ◽  
Author(s):  
Omer Karin ◽  
Uri Alon ◽  
Eduardo Sontag
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
The Other ◽  
Apparent Discrepancy ◽  
Parameter Identifiability ◽  
Other Hand ◽  
The Face ◽  
System Variables

AbstractWe recently identified a motif for dynamical compensation (DC) – a property where a system maintains the dynamics and steady-state of a regulated variable robust in the face of fluctuations in key parameters. Such parameters are therefore unidentifiable from measurements of the regulated variable at steady-state. On the other hand, since the models showing dynamical compensation are typically non-redundant, their parameters are identifiable from experimental data. We clarify this apparent discrepancy by requiring that the parameters of DC circuits be identifiable both away from steady-state and when measuring other system variables. We use this observation to provide a definition for DC in terms of parameter identifiability and discuss its relevance for the examples provided in Karin et al.

P6303Developmental origin of cardiac macrophages in steady state and myocardial infarction

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
T Weinberger ◽  
R Thaler ◽  
V Schneider ◽  
D Messerer ◽  
S Massberg ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Bone Marrow ◽  
Steady State ◽  
Acute Phase ◽  
Cardiac Remodeling ◽  
The Other ◽  
Bone Marrow Chimera ◽  
Resident Macrophage ◽  
Developmental Origin ◽  
Other Hand

Abstract Background Macrophages are the most abundant immune cells in the myocardial tissue in steady state. The sterile inflammation caused by myocardial infarction triggers a massive immune reaction, which leads to a profound influx of neutrophils and monocytes. In the postacute phase of infarction macrophages play an essential role in reparative processes. Recently, it has become clear that macrophages in the heart have a dual developmental origin from embryonic and bone marrow (BM) hematopoiesis. In this study, we sought to investigate the contribution of embryonic derived macrophages to the cardiac macrophage pool in steady state as well as the acute and chronic phase after ischemia/reperfusion injury. Methods/Results To address the origin of macrophages in steady state we used different models of lineage tracing to determine the developmental origin of cardiac macrophages. Using FLT3-Cre mice and radiation-independent CD45.1/.2 bone marrow chimera, we found that the resident macrophage population in the heart is mainly independent of definitive hematopoiesis (approximately 70–80% of cardiac macrophages). The BM-dependent population on the other hand is replenished by blood-derived monocytes. Further we used the radiation-independent CD45.1/.2 bone marrow chimera to characterize the origin of macrophages at different time points after I/R-injury. In the acute phase after myocardial infarction we observed a profound influx of BM-derived macrophages in the infarct region and also in the remote area. 30 days after I/R-injury the composition of the resident macrophage pool was mainly comprised of BM-independent macrophages, similar to steady state conditions. To address the role of BM-derived macrophages we used CCR2-ko mice, which have low numbers of inflammatory monocytes in peripheral blood. CCR2-ko mice showed reduced macrophage numbers in the acute phase after myocardial infarction. Using positron emission tomography we investigated the influence of CCR2-deficiency on cardiac function after I/R-injury. In comparison to WT mice, CCR2-ko mice showed a significantly increased infarct size. Cardiac remodeling, determined by end-diastolic volume, on the other hand was improved in CCR2-ko mice. The ejection fraction was similar in both groups. Conclusion The cardiac macrophage pool is mainly comprised of BM-independent macrophages. In response to I/R-injury monocyte-derived macrophages transiently enter the myocardium but do not persist in significant numbers over time. The influx of BM-derived macrophages after I/R-injury was reduced using CCR2-ko mice, which led to improved cardiac remodeling. Our findings are of potential importance for understanding the cardiac immune response and for the therapeutic targeting of macrophages in inflammatory conditions. Acknowledgement/Funding German Society of Cardiology, German Centre for Cardiovascular Research, LMU Excellence, SFB 914

scholarly journals Population ageing: demographic security threat or silver industry development potential

2019 ◽  
Vol 6 (3) ◽  
pp. 234-242
Author(s):  
Anna Sergeevna Zueva ◽  
Tatiana Sergeevna Khrolenko
Keyword(s):  
Older Persons ◽  
International Experience ◽  
Population Ageing ◽  
The Other ◽  
Security Threat ◽  
Development Potential ◽  
Industry Development ◽  
Other Hand ◽  
The One ◽  
Older Citizens

The authors grasped the crucial points of such demographic phenomenon as population ageing and defined the most important consequences for the economy of the country on the increase in the proportion of older persons. On the one hand, population ageing is noted as Russian demographic security threat. On the other hand, the international experience of the formation of the silver industry and focused on a certain category of older citizens economy are noticed. Prospects of development of the market of services for pensioners are estimated.

Study of Steady-State Periodic Motions of Crawling Robot Modules under External Disturbances

2021 ◽  
pp. 18-29
Author(s):  
L.Yu. Vorochaeva ◽  
S.I. Savin
Keyword(s):  
Numerical Simulation ◽  
Steady State ◽  
External Force ◽  
Driving Force ◽  
Phase Mismatch ◽  
The Other ◽  
Periodic Motions ◽  
Static Error ◽  
External Disturbances ◽  
Qualitative Characteristics

The development and design of a multi-module crawling robot requires an elaboration of each aspect of its motion in the implementation of various tasks, including holding the position of such a robot under a driving force. This problem has been solved for a three-module crawling robot, one of the end supports of which was fixed on the surface, and the other was affected by the harmonic external force changing according to the meander law. For this purpose, a module control system based on the CTC controller has been proposed. Numerical simulation has been used to study the quantitative and qualitative characteristics of robot module vibrations depending on the ratio of the amplitudes of the vertical and horizontal components of the force and the phase mismatch between them. It is found that when the external force vertical and horizontal amplitudes are equal, the module angles fluctuate relative to the set values, and when there is a certain ratio between the amplitudes, a static error appears which increases as the specified ratio moves away from 1.

scholarly journals Investigation of the visual appearance of different skirt styles and materials during the fitting simulation with Lectra Modaris

2021 ◽  
Vol 2 (2) ◽  
pp. 141-150
Author(s):  
Tibifez Hailu Nechno ◽  
Yordan Kyosev ◽  
Mulat Alubel ◽  
Sybille Krzywinski
Keyword(s):  
Numerical Simulation ◽  
Material Properties ◽  
The Other ◽  
Comparison Result ◽  
Visual Appearance ◽  
Other Hand ◽  
Clothing Style ◽  
Best Fitting ◽  
The Right

This paper examines the influence of different fabric types and material properties on the visual appearance of three types of skirt styles using numerical simulation. The purpose of the simulation is to present and analyze the appearance of virtual garments, create the best-fitting pattern pieces, and choose the appropriate fabric type based on the multiple clothing styles to achieve the intended design. The results show that when the type of fabric changes without changing the clothing style and on the other hand the style changes without changing the type of material, the appearance of the garment changes and the effect can be clearly seen with the 3d comparison result. These changes should be taken into account when choosing the right fabric for different styles.

A Study of the Development of an Analytical Wall Function for LES

2014 ◽  
Author(s):  
R. S. Amano ◽  
Takahiko Hasegawa ◽  
Shaohua Shen
Keyword(s):  
Boundary Layer ◽  
Steady State ◽  
Cfd Simulation ◽  
The Other ◽  
Unsteady State ◽  
Wall Function ◽  
Other Hand ◽  
Log Law ◽  
Complicated Geometry ◽  
Steady State Simulation

In order to invent a new near-wall treatment for turbulence in Computational Fluid Dynamics (CFD) simulation, an Analytical Wall Function (AWF) has been studied and shown that it is possible to work accurately with Reynolds Averaged Navier-Stokes (RANS) Simulation even for complicated geometry such as impinging jet flow or separation and reattachment flow. One of the most common wall functions is the Standard Wall Function (SWF) which assumes log-law inside the boundary layer. However, there is a problem that SWF has been used for industrial applications even though it is difficult to analyze the turbulence phenomenon in a complicated geometry accurately because log-law is not applicable in that geometry. On the other hand, since AWF derives the boundary condition on the wall by integrating analytically the boundary layer equation in wall adjacent cells, it can analyze the turbulence accurately even in complicated geometry. AWF has an advantage over SWF from this point of view. In this study, AWF was improved and optimized for Large Eddy Simulation (LES) by changing the way of modeling of eddy viscosity inside the boundary layer for steady state simulation to that for unsteady state simulation. This is because RANS is a steady state simulation; on the other hand, LES is unsteady state simulation, which is one of the largest differences between them. The accuracy of the new AWF for LES (LES-AWF) was validated by both of experimental results and CFD simulation results. Both of the experiment and CFD simulation are conducted in the wind tunnel.

Sign in / Sign up

Export Citation Format

Share Document