scholarly journals A Two-dimensional Mathematical Model for Long-term Contaminated Groundwater Pollution Measurement around a Land Fill

2020 ◽  
Vol 8 (1) ◽  
pp. 61-74
Author(s):  
Jirapud Limthanakul ◽  
Nopparat Pochai
Keyword(s):  
Mathematical Model ◽  
Groundwater Pollution ◽  
Contaminated Groundwater ◽  
Two Dimensional ◽  
Pollution Measurement

SALINITY BUILD-UP DUE TO BRINE DISCHARGES INTO SHALLOW COASTAL WATERS

2009 ◽  
Vol 23 (03) ◽  
pp. 541-544 ◽  
Author(s):  
DONGDONG SHAO ◽  
ADRIAN WING-KEUNG LAW
Keyword(s):  
Mathematical Model ◽  
Coastal Waters ◽  
Two Dimensional ◽  
Longshore Current ◽  
Source Condition ◽  
Continuous Point ◽  
Characteristic Features ◽  
Shallow Coastal Waters ◽  
Transient And Steady State

A two-dimensional mathematical model simulating the long-term build-up of salinity around the brine outfall is developed in this paper. A flat seabed and steady longshore current are assumed as a first step towards modelling the actual scenario. Transient and steady-state analytical solutions for continuous point source condition are derived. These solutions are then applied to assess shoreline/offshore discharge. Characteristic features such as the temporal buildup of salinity excess and the variation of the shoreline salinity with respect to time and outfall location are investigated. The effect of the advection-to-diffusion ratio ν in the modelling results is also discussed.

A Simple Two-Dimensional Electrical Analog Model for Wind-Driven Circulation in the Gulf of St. Lawrence

1966 ◽  
Vol 23 (9) ◽  
pp. 1411-1438 ◽  
Author(s):  
B. L. Blackford
Keyword(s):  
Mathematical Model ◽  
Pressure Gradients ◽  
Two Dimensional ◽  
Analog Model ◽  
Analog Simulation ◽  
Electrical Analog ◽  
Horizontal Pressure ◽  
Excitation Force ◽  
Comparison Of The Results

A mathematical model of water circulation in an enclosed basin was examined, taking into account the effects of vertical friction, Coriolis force, and horizontal pressure gradients. Wind stress at the free surface was the only excitation force taken into account. The resulting vorticity equation was applied to the Gulf of St. Lawrence by using an electrical analog simulation technique. Solutions were obtained for two situations: one in which the circulation was vertically averaged and another which showed the circulation at several depths. Comparison of the results with broad features of the Gulf circulation derived from synoptic surveys suggested that the wind plays an important role in producing the long-term circulation. The model did not duplicate all of the features of the long-term circulation, but suggested several phenomena for further direct study.

Two Dimensional Unsteady State Mathematical Model for dispersion of Chlorine in Water in a Channel

2011 ◽  
Vol 3 (8) ◽  
pp. 503-505
Author(s):  
Jaipal Jaipal ◽  
◽  
Rakesh Chandra Bhadula ◽  
V. N Kala V. N Kala
Keyword(s):  
Mathematical Model ◽  
Two Dimensional ◽  
Unsteady State

Modelling of Moisture Movement in Wood during Outdoor Storage

2001 ◽  
Vol 6 (2) ◽  
pp. 3-14 ◽  
Author(s):  
R. Baronas ◽  
F. Ivanauskas ◽  
I. Juodeikienė ◽  
A. Kajalavičius
Keyword(s):  
Experimental Data ◽  
Finite Difference ◽  
Climatic Conditions ◽  
Two Dimensional ◽  
Moisture Movement ◽  
Finite Difference Technique ◽  
Long Term Storage ◽  
Space Formulation ◽  
Term Storage

A model of moisture movement in wood is presented in this paper in a two-dimensional-in-space formulation. The finite-difference technique has been used in order to obtain the solution of the problem. The model was applied to predict the moisture content in sawn boards from pine during long term storage under outdoor climatic conditions. The satisfactory agreement between the numerical solution and experimental data was obtained.

Application of the method of mathematical modeling for forecasting channel deformations at the underwater crossing of the main pipeline

2020 ◽  
Vol 10 (6) ◽  
pp. 599-609
Author(s):  
Valery А. Gruzdev ◽  
◽  
Georgy V. Mosolov ◽  
Ekaterina A. Sabayda ◽  
◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Roughness Coefficient ◽  
Computational Domain ◽  
Channel Deformations ◽  
Geological Surveys ◽  
Kuban River ◽  
The Stability ◽  
Protective Structures

In order to determine the possibility of using the method of mathematical modeling for making long-term forecasts of channel deformations of trunk line underwater crossing (TLUC) through water obstacles, a methodology for performing and analyzing the results of mathematical modeling of channel deformations in the TLUC zone across the Kuban River is considered. Within the framework of the work, the following tasks were solved: 1) the format and composition of the initial data necessary for mathematical modeling were determined; 2) the procedure for assigning the boundaries of the computational domain of the model was considered, the computational domain was broken down into the computational grid, the zoning of the computational domain was performed by the value of the roughness coefficient; 3) the analysis of the results of modeling the water flow was carried out without taking the bottom deformations into account, as well as modeling the bottom deformations, the specifics of the verification and calibration calculations were determined to build a reliable mathematical model; 4) considered the possibility of using the method of mathematical modeling to check the stability of the bottom in the area of TLUC in the presence of man-made dumping or protective structure. It has been established that modeling the flow hydraulics and structure of currents, making short-term forecasts of local high-altitude reshaping of the bottom, determining the tendencies of erosion and accumulation of sediments upstream and downstream of protective structures are applicable for predicting channel deformations in the zone of the TLUC. In all these cases, it is mandatory to have materials from engineering-hydro-meteorological and engineering-geological surveys in an amount sufficient to compile a reliable mathematical model.

Electron-transport-layer-free two-dimensional perovskite solar cells based on a flexible poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) cathode

2021 ◽  
Author(s):  
Zhihai Liu ◽  
Lei Wang ◽  
Chongyang Xu ◽  
Xiaoyin Xie
Keyword(s):  
Solar Cells ◽  
Electron Transport ◽  
Power Conversion ◽  
Perovskite Solar Cells ◽  
Transport Layer ◽  
Electron Transport Layer ◽  
Two Dimensional ◽  
High Power Conversion Efficiency ◽  
Long Term Stability

Recently, Ruddlesden–Popper two-dimensional (2D) perovskite solar cells (PSCs) have been intensively studied, owing to their high power conversion efficiency (PCE) and excellent long-term stability. In this work, we fabricated electron-transport-layer-free...

scholarly journals On the effect of antiresorptive drugs on the bone remodeling of the mandible after dental implantation: a mathematical model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mehran Ashrafi ◽  
Farzan Ghalichi ◽  
Behnam Mirzakouchaki ◽  
Manuel Doblare
Keyword(s):  
Mathematical Model ◽  
Bone Density ◽  
Bone Remodeling ◽  
Dental Implants ◽  
Implant Design ◽  
Patient Specific ◽  
Dental Implantation ◽  
Antiresorptive Agents ◽  
Antiresorptive Drugs

AbstractBone remodeling identifies the process of permanent bone change with new bone formation and old bone resorption. Understanding this process is essential in many applications, such as optimizing the treatment of diseases like osteoporosis, maintaining bone density in long-term periods of disuse, or assessing the long-term evolution of the bone surrounding prostheses after implantation. A particular case of study is the bone remodeling process after dental implantation. Despite the overall success of this type of implants, the increasing life expectancy in developed countries has boosted the demand for dental implants in patients with osteoporosis. Although several studies demonstrate a high success rate of dental implants in osteoporotic patients, it is also known that the healing time and the failure rate increase, necessitating the adoption of pharmacological measures to improve bone quality in those patients. However, the general efficacy of these antiresorptive drugs for osteoporotic patients is still controversial, requiring more experimental and clinical studies. In this work, we investigate the effect of different doses of several drugs, used nowadays in osteoporotic patients, on the evolution of bone density after dental implantation. With this aim, we use a pharmacokinetic–pharmacodynamic (PK/PD) mathematical model that includes the effect of antiresorptive drugs on the RANK/RANK-L/OPG pathway, as well as the mechano-chemical coupling with external mechanical loads. This mechano-PK/PD model is then used to analyze the evolution of bone in normal and osteoporotic mandibles after dental implantation with different drug dosages. We show that using antiresorptive agents such as bisphosphonates or denosumab increases bone density and the associated mechanical properties, but at the same time, it also increases bone brittleness. We conclude that, despite the many limitations of these very complex models, the one presented here is capable of predicting qualitatively the evolution of some of the main biological and chemical variables associated with the process of bone remodeling in patients receiving drugs for osteoporosis, so it could be used to optimize dental implant design and coating for osteoporotic patients, as well as the drug dosage protocol for patient-specific treatments.

Performance improvement of inverted two-dimensional perovskite solar cells using a non-fullerene acceptor as the trap passivator

2021 ◽  
Author(s):  
Eun-Cheol Lee ◽  
Zhihai Liu
Keyword(s):  
Solar Cells ◽  
Power Conversion Efficiency ◽  
Performance Improvement ◽  
High Power ◽  
Power Conversion ◽  
Perovskite Solar Cells ◽  
Two Dimensional ◽  
High Power Conversion Efficiency ◽  
Long Term Stability

Recently, Ruddlesden–Popper two-dimensional (2D) perovskite solar cells (PSCs) have been intensively studied, owing to their high power conversion efficiency (PCE) and excellent long-term stability. In this work, we improved the...

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