Johnny Zhang

9 Questions 16 Answers 0 Followers

Questions related from Johnny Zhang

An code example of Newton's method for solving diffusion equation with FDM?

I am trying to solve a time-dependent diffusion equation with finite-difference discretizations using the Newton–Raphson method. However, I encountered some problems in convergence--the solution...

03 February 2022 6,083 4 View

Why a reflection seismic profile on land usually is not so clear compared with subsea for shallow strata?

Why a reflection seismic profile on land usually is not so clear compared with under ocean bottom for shallow strata? I see in many papers the reflection seismic profiles for shallow strata are...

19 May 2021 8,818 9 View

An analytical solution of radial diffusion equation?

I want to find the analytical solution of a radial diffusion system (1D cylindrical coordinates). Here what is considered is pressure diffusion. The conditions are simple and similar to the...

30 September 2020 2,593 4 View

What is the difference between Rayleigh scattering based fiber optic dynamic strain and static strain sensing?

In literature, I find that both distributed acoustic sensing (DAS; for dynamic strain measurement) and distributed strain sensing (DSS; for static strain measurement) using methods on the basis of...

18 February 2020 9,037 7 View

How large the well-drilling induced changes in pore pressure ?

Could anyone tell me how large usually the magitude of induced pore pressure changes during a well-drilling in an aquifer? In my case, it is a near 200 m deep well. Perhaps the induced pore...

07 January 2020 4,770 3 View

Where can I find an analytical solution of diffusion equation with zero flux boundary at outlet?

Could anyone tell me that where can I find an analytical solution of diffusion equation (PDE) with 1D zero flux boundary at outlet? I need this for calculating rock permeability from pressure...

20 December 2019 6,405 1 View

A relationship bettween rock compressibility and permeability (or storage coefficient and hydraulic conductivity)?

As the title, where can I find a relation describing the compressibility and permeability of sedimentary rocks? I am trying to use it as a first guess of initial condition in numerical modeling...

07 October 2019 8,412 6 View

Is it possible to make the Teledyne Isco Syringe Pump automatically adjust the pressure condition according to the feedback of another pump?

In an experiment, I want to control the change of the pressure of one Teledyne Isco Syringe pump B, according to the read pressure of another pump A. Pump A is set by step increasing constant...

09 March 2015 6,048 5 View

A question on the calculation of dielectric constant (or relative permittivity) from capacitance ?

I conducted a complex electrical impedance measurement for a water partially saturated rock.My complex electrical impedance data (Z' and Z'') between 500 ~10000 Hz can be well fitted by a Debye...

18 February 2015 2,620 8 View