Interface - Science topic

What do we mean by sharp and diffused interface model in the context of multiphase flows?

Kindly clarify the difference with the help of famous methods, i.e., in which category do they fall: phase field method, LBM, LS, VOF, CLSVOF, etc.?

Which one should be preferred and why?

It is kindly requested, if you can, to help with the references to support your answer.

Best regards.

Can somebody explain the difference in two terms : Interface tracking methods, and interface capturing methods in the context of multiphase flow modelling?

There are multiple methods, like, phase field model, level set, which categories do they fall in and why? if someone can help clarify this. please.

On the optimization of the interface between biomaterials and semiconductors.

How can biomaterials be effectively combined with semiconductor materials to develop biosensors or implantable medical devices? How do the physicochemical properties between the interfaces affect device performance?

Hey , i am a college student , i try to simulate a microbond test between a fiber carbon/epoxy resin on Ansys workbench , and i need to set a cohesive elements , i can insert a fracture and i have the choice between interface delamination or contact debonding , i know the difference between both ( the definition of the material law and the elements that are used Inter20X and CONTA..) , at first i tried to do it using a contact debonding but the results are not satisfying so i thought that the interface delamination would be a better choice since it used interface elements that are better to simulate an adhesive ... but i don't see how to set correctly the control match on mesh , i mean which faces i should select ?

I've used the cut and extrude options in the Parts module and the cut operation in the Assembly module. However, when I assemble the soil and pile, there are small gaps or overlaps at the interface. Are there any other techniques or best practices to ensure a perfect fit between the two geometries?

I am currently simulating a NiO/Ga2O3 p-n junction diode, but I am facing an issue where the diode is not showing any current, even at 5 V. Both materials (NiO and Ga2O3) work fine individually in separate simulations. However, when simulating the NiO/Ga2O3 heterojunction diode, no current flows, and I do not observe any variation in self-heating.

I have defined the material properties for both NiO and Ga2O3 correctly, and when I simulate Ga2O3 with other p-type materials like SiC or GaN, the diode works as expected. Could anyone help me understand why current is not flowing in the NiO/Ga2O3 heterojunction device? Is there a special model or specific interface properties that I need to define for this system?

Any insights or suggestions would be greatly appreciated!

When designing hydrogel filler-organic resin coating materials, how can we achieve good distribution of the organic filler within the matrix and form a tight interface?

Reservoir Engineering: Multi-Phase Fluid Flow

1.  Whether the generalization of Darcy’s law to the simultaneous flow of two immiscible fluids by Wyckoff and Botset (eight years following 1856’s Darcy’s law) remains sufficient enough to bring in capillary effects, although, each immiscible fluid obeys Darcy’s law within the diminished pore-space (where, each immiscible fluid occupies an available space in which it can flow, which consists of the pore space minus the space the other immiscible fluid occupies)?

2.  Even though, mass conservation equation considers an explicit flow rate for each fluid phase (water, oil & gas), how does “the combined flow” react to a given pressure drop @ field-scale?

In such cases, whether, the entire reservoir’s flow regime will uniformly obey the linear relation between flow rate and pressure drop?

What is the guarantee that both the immiscible fluids will tend to percolate @ low flow rates (where, the capillary forces remain to be too strong for the viscous forces to move the fluid interfaces), so that linear Darcy’s law would still prevail?

Won’t the enhanced flow rates lead to a non-linearity between flow rate and pressure drop, resulting from the gradual increase in mobilized interfaces?

If not, then, the two different (say, oil and water) (Newtonian) immiscible fluids flowing @ pore-scale - do no more behave as a (single) Newtonian fluid @ continuum-scale (if the effective viscosities of oil and water remain to depend on shear rate)?

In essence, how do we have a control over the following four different scenarios in an oil reservoir @ field-scale?

(a)          Low flow rates (where, the capillary forces remain to be too strong for the viscous forces to move the fluid interfaces, and thereby, still obeying linear Darcy’s law)

(b)         Moderately higher flow rates (appearance of strong pressure fluctuations, but, still obeying linear Darcy’s law)

(c)          Significantly higher flow rates (where, non-linearity set in, and a power law relation between flow rate and pressure drop gets developed)

(d)         Very high flow rates (where, capillary forces become negligible compared to viscous forces, and, eventually, comfortably following linear Darcy’s law)

3.   Feasible to capture the main mechanism responsible for the non-linearity in the flow-pressure relationship @ laboratory-scale?

If so, then, how could we deduce the threshold pressure (the pressure drop at which the interfaces start getting mobilized), associated with the correlation between time-averaged flow rate and excess pressure drop?

And also, would it remain feasible to capture the movement of the interfaces, which consumes energy, and which, eventually, leads to the reduction in the effective permeability @ lab-scale?

Suresh Kumar Govindarajan

Professor (HAG)

IIT Madras

22-Sep-2024

Dear Fulden: I am starting to use the Simbiology interface of MAtlab and I found out online that you are a specialist in its use. I wish to ask you a question.

I have already learned to create kinetic models in Simbiology and do simulations by providing values for the parameters. However, I cannot see how to simulate in the interfase the time course of a reaction such as, for example, A + B <-> C, starting simultaneously with different initial concentrations of A, keeping the initial concentration of B constant.

Thanks a lot

Sergio B. Kaufman

(sergiobkaufman@gmail.com)

To induce polarization and study of drain current.

Hello everyone,

I am working on a deep learning power control project using NetSim. So far, I have successfully implemented a tabular Q-learning algorithm and obtained positive results. Now, I am looking to implement advanced reinforcement learning algorithms such as actor-critic and proximal policy optimization (PPO) using Gymnasium.

Could anyone provide guidance on how to interface NetSim with Gymnasium (https://github.com/Farama-Foundation/Gymnasium) for applying these RL algorithms? Any examples or resources would be greatly appreciated.

Thank you!

Chemical EOR: Microgels

1. Could microgels (soft gel particles with 3-D network structure in the size of microns, whose physical status wavers between colloid particles and polymers in a solvent) effectively stabilize emulsions (Mickering Emulsions as against conventional Pickering Emulsions stabilized by solid particles) in an oil-water system?

Whether microgelation would significantly elevate the interfacial pressure and modulus @ oil-water interface (in EOR application)?

In case, if it ends up with a mitigated dilatational modulus, then,

would it maintain a stable anti-deformation ability (during amplitude sweep) in an oil-water system?

2. Can we efficiently utilize the viscoelastic nature of microgels that permits them to stretch and deform; and which in turn leads to an enhanced adsorption section area @ oil-water interface that would make us better understand the interfacial behavior of microgels and its associated fundamental mechanism associated with the stability of the interface and emulsion?

Whether the traditional linear rheology will be able reflect the complete details on the interfacial viscoelasticity,

especially @ higher frequencies and @ large amplitudes

(as against the traditional small amplitude oscillation,

where non-linear responses @ high deformation and high deformation rate remain ignored)?

Will it end up with a relatively low degree of non-linearity under significant ionic strength (with acidic and basic dominant scenarios),

while, enhancing emulsifying capacity and improving the interfacial viscoelasticity in an oil-water system?

3. With an enhanced specific surface area and with an elevated exposure of hydrophobic groups on the surface, to what extent, would it remain feasible to capture the details on

(a) microgel diffusion in the bulk phase;

(b) adsorption;

(c) distortion of microgels @ interface; &

(d) reorganization of microgel aggregates within the surface?

Suresh Kumar Govindarajan

Professor (HAG)

31-Aug-2024

How can I interface different python (or any other language) based AI/ML models with NetSim? Any examples would be very helpful.

i am a beginner to ansys fluent and working on the analysis of a naca008 aerofoil but after the meshing in fluent section its showing a error "WARNING: Unassigned interface zone detected for interface aerofoil-contact_region-trg" and i am unable to initialize the flow so someone help me to rectify this error

Chemical EOR

1. What is the average thickness of the brine film (1 nm??) that exists between reservoir rock mineral surfaces and crude-oil droplets – associated with a carbonate reservoir?

In such cases, whether the oil requires to be removed from solid rock surfaces, or, from relatively smoother brine surfaces?

With nanoparticle dispersion, what is the expected fraction of oil that remains directly in contact with the rock surface? With NPD, What is the expected fraction of oil that remains adhering to the solid rock surfaces through electrostatic forces? What will be the required threshold energy level towards separating oil from the surfaces given the imbalances between Brownian motion and electrostatic repulsion between nanoparticles (for a given nanoparticle size distribution)? Upon using Darcian approach, how would the details on the evolution of molecular structures of rock-brine interface and brine-oil interfaces approaching molecular thickness (from its original brine film thickness) would remain to be helpful?

If we have a slip @ brine-oil interface, how will we be able to quantify the effective viscosity of brine films?

2. Whether the degree of disjoining pressure associated with such brine films would significantly influence the resulting contact angle of oil droplets on rock surfaces?

Whether the alterations in ionic distributions in the Electric Double Layer of the brine film - as a function of brine film thickness and bulk ion concentration – would have an impact on the resulting contact angle?

3. With the thickness of the brine-film bounded between ‘rigid solid rock surface’ and relatively a ‘smooth diffusive oil surface’, would it remain feasible to upscale the details associated with Debye length of brine; the hydration diameter of ions in brine; the characteristic length of the density oscillation of brine molecules near solid rock surfaces; and the width of diffuse brine-oil interfaces – to a relatively larger pore-scale (leaving aside Darcy’s continuum-scale) – towards formulating a new EOR concept or facilitating the improvement of existing EOR technique?

Suresh Kumar Govindarajan

Professor (HAG)

12-Aug-2024

As I understood, Vbi is the difference between the conduction band energy level between the Absorber and ETL interface to the Absorber and HTL interface (EC_Abs/ETL - EC_Abs/HTL) divided by the elementary charge (q).

but I am confused about identifying the table's built-in potential (Vbi) value.

Please anyone suggest to me, in full detail.

I have newly installed GaussView 6.0 on Linux Ubuntu 22, but when I open it, it does not display any operation functions, no text or icons. However, when I open other graphical interface programs such as VMD, there are no problems. What is causing this

I am trying to test the coincidence lattice method for the interface between wurtzite (0001) GaN and cubic diamond (111). How do I rotate the two lattices with respect to one another using VESTA?? I am fairly familiar with the VESTA interface and have used it extensively, just not for something like this. For reference, I am wanting to do something like in figure 4 of this paper ( ), where the hexagonal lattice is matched to the cubic lattice (experimental results have told us that the angle is somewhere between 20-25 degrees). The ultimate goal is to create an interface to study thermal transport across the interface using MD simulations in VASP. Thank you in advance for any help/advice.

I submitted my journal and got some comments, I have answered and corrected all the comments from the reviewer but I don't understand how to answer this question.

any expert researcher help me to explain what I have to do and how?

What can the authors say about the interface problem between the concrete core and the CFRP shells? What is the adhesion type like? How can core-shell bonding affect performance?

Hi,

I need to find out the effect of muddy bottoms in ship resistance in shallow water canals. For that I need to simulate two interfaces, ie) air water interface and mud water interface (I have to specify the thickness of the mud layer). How this done in STARCCM+?

Thanks, and regards.

I want to quantify some roughness parameters using AFM data. I tried to quantify some of them by Gwyddion software but its HHCF doesn’t have a fitting function contemplating all parameters I need.

Fit function that I found in my Gwyddion version:

y = 2sigma^2 * ( 1 - exp ( - ( r/E )^2 ))

, where, sigma is the interface width and E is the lateral correlation lenght.

Fit funtion that I was looking for:

y = 2sigma^2 * ( 1 - exp ( - ( r/E )^(2a) ))

, where a is the Hurst exponent.

I also tried to export data to origin and tried to set a new fitting function, but I got stuck on how to build it. Something went wrong since my limit bounds aren't being followed.

If anyone could help me with some insights I will be really grateful.

Hi, I am using VASP to simulate interface of 2 block material slabs. After bringing them together I can get the stress tensor for the whole simulation box from OUTCAR. However, is there any way to calculate local stress tensors for these 2 sides of the interface separately?

What type of interface layer is appropriate for evaporation within the temperature range of 100-200°C when creating a two-layered structure using multilayer formation? Specifically, discuss the characteristics and suitability of various interface layers such as Nafion, polypyrrole, polyaniline, and PEDOT/PSS in this process.

What is a phenomenon called "false vacuum collapse"?

as you know :

Mean field energy and bubble formation. The cloud is initially prepared in FV with all atoms in |↑⟩ (A). Although the single spin mode |↓⟩ is lower in energy in the center of the cloud (E↓E↑), the opposite is true in the low-density tails. The interface (domain wall) between ferromagnetic regions with opposite magnetism has positive (kinetic) energy, which is added to the minimum double energy resulting from ferromagnetic interaction. Macroscopic tunneling can occur resonantly in the bubble mode (B), which has a |↓⟩ bubble in the center. The increase in core energy compensates for the cost of domain-wall energy. Crossing the barrier can be caused by quantum fluctuations at zero temperature (full arrow) or by thermal fluctuations at finite temperature (empty arrow). After the tunneling process, the bubble size increases in the presence of dissipation to reach the true vacuum (TV) state (C), without returning to (A). Credit: Nature Physics (2024). DOI: 10.1038/s41567-023-02345-4

An experiment carried out in Italy with theoretical support from the University of Newcastle provided the first experimental evidence of vacuum decay.

In quantum field theory, when a not-so-stable state becomes a true stable state, it is called a "pseudovacuum collapse." This happens through the creation of small local bubbles. While existing theoretical work can predict how often this bubble formation occurs, there is not much empirical evidence.

The Pitaevskii Center for Supercold Atoms Laboratory for the Bose-Einstein Condensation in Trento reports for the first time observations of phenomena related to the stability of our universe. The results are the result of a collaboration between the University of Newcastle, the National Institute of Optics CNR, the Department of Physics at the University of Trento and TIFFA-INFEN and are published in Nature Physics.

The results are supported by theoretical simulations and numerical models, confirming the origin of the decay quantum field and its thermal activation, and opening the way to simulate out-of-equilibrium quantum field phenomena in atomic systems.

This experiment uses a supercooled gas at a temperature less than one microkelvin from absolute zero. At this temperature, the bubbles appear as the vacuum collapses, and Newcastle University's Professor Ian Moss and Dr Tom Billam were able to conclusively show that the bubbles are the result of heat-activated vacuum collapse.

Ian Moss, Professor of Theoretical Cosmology at Newcastle University's School of Mathematics, Statistics and Physics, said: "Vacuum collapse is thought to play a central role in the creation of space, time and matter in the Big Bang, but so far it has not. In particle physics, the decay of the Higgs boson vacuum changes the laws of physics and creates what has been described as the 'ultimate ecological catastrophe'."

Dr Tom Bilam, Senior Lecturer in Applied/Quantum Mathematics, added: "Using the power of ultracold atom experiments to simulate analogues of quantum physics in other systems – in this case the early universe itself – is a very exciting area of research. the moment."

This research opens new avenues in understanding the early universe as well as ferromagnetic quantum phase transitions.

This groundbreaking experiment is only the first step in the discovery of vacuum decay. The ultimate goal is to find vacuum decay at absolute zero temperature, where the process is driven solely by quantum vacuum fluctuations. An experiment in Cambridge, supported by Newcastle as part of the national QSimFP collaboration, is doing just that.

Stam Nicolis added a reply:

Just what the name says: There are many physical systems, whose potential energy, in the absence of fluctuations, possesses more than one minima. If these minima are not degenerate, it can occur that one is the absolute minimum, however, due to the choice of initial conditions, the system is found in another minimum. In the absence of fluctuations, it will stay in the potential well of that minimum.

In the presence of fluctuations, it can occur that the relative minimum is no longer a minimum: In that case the system won't stay there forever and it is possible to compute the rate at which it will evolve to another state.

While the presence of fluctuations is a necessary condition, it isn't sufficient for transitions to be possible.

Sergey Shevchenko added a reply:

“What is a phenomenon called "false vacuum collapse"?”

- the answer to this question is: the question really is absurdity, since really there cannot be fundamentally any “false vacuum”, i.e. that really is an fundamental absurdity, and so its “collapse” is absurdity as well.

Though yeah, in mainstream physics really rather numerous fantastic/mystic “true/false vacuums” really exist, and corresponding publications, where corresponding fantastic/mystic properties and effects of/in the vacuums are “discovered”, are well popular and numerous.

That exists in the mainstream completely logically inevitably from the fact that in the mainstream all really fundamental phenomena/notions, first of all on this case “Matter”– and so everything in Matter, i.e. “particles”, “fundamental Nature forces” – and so “fields”, etc., including “vacuum”, “Consciousness”, “Space”, “Time”, “Energy”, “Information”, are fundamentally completely transcendent/uncertain/irrational,

- and so in every case when the mainstream addresses to something that is really fundamental, the results completely inevitably are only some the fantasies.

More see recent SS post in https://www.researchgate.net/post/What_is_a_super_vacuum_Is_the_earth_in_a_vacuum_And_what_is_dark_energy , and links in the post; reDzennn comment, 9/8 [because of too active moderator] passages, to a Nature Physics (2024) paper in

https://phys.org/news/2024-01-phenomenon-false-vacuum-decay.html) directly relates to the thread question.

Zoltan Vilagosh added a reply:

Not that complicated really. False vacuum example = because you cannot see over the hill, you think are at the lowest level possible. This makes you think you have no potential energy left. But a surprise awaits if you make it to the top of the hill...you tumble lower onto the vast endless plain on the other side.

__/\O/\

\

\__O

Sergey Shevchenko added a reply:

“…Not that complicated really. False vacuum example = because you cannot see over the hill, you think are at the lowest level possible. This makes you think you have no potential energy left. But a surprise awaits if you make it to the top of the hill...you tumble lower onto the vast endless plain on the other side. …..”

- that above looks as tooo not complicated passage really, though, again, on such level the authors of the paper in a top physical Nature Physics (2024) journal also thought,

- which “discovered” “false vacuum bubbles decays” in some Bose-Einstein Cond sate of Na-23 atoms, more see reDzennn comment, 8 passages, in https://phys.org/news/2024-01-phenomenon-false-vacuum-decay.html, the strangely removed by moderator passage is in the end of whole comments series.

Though yeah, the really full stop “false vacuum” theories are rather popular in mainstream physics, including rather popular is the theory that Matter was created soon 14 billion years ago at some “bubble in spacetime decay”. Thank heavens till now no any even small bubbles didn’t decay near Earth, and nowhere in Space at all, in last 10 billion of years Milky Way existence.

However, again, this full stop – and so quite easily composed - fantasies are so rather popular, and in this case so some people don’t like the comment, correspondingly it is heavily “down voted”.

Juan Weisz added a reply

Perhaps vacuum does not collapse,

but you know the saying, nature abhors vacuum.

Harri Shore added a reply

False vacuum collapse is a theoretical concept in particle physics and cosmology. It suggests that our universe might currently exist in a metastable vacuum state, also known as a false vacuum. If this false vacuum were to collapse to a lower energy state, it could trigger catastrophic consequences, such as the destruction of all matter and the laws of physics as we know them. This hypothetical scenario is based on certain models in quantum field theory and the structure of the universe. However, there is currently no empirical evidence to support the occurrence of false vacuum collapse.

Harri Shore added a reply:

The "false vacuum collapse" refers to a hypothetical cosmic event that could have catastrophic implications for the universe as we know it. In theoretical physics, a vacuum state is considered to be the lowest possible energy state in which a quantum field can exist. A "true vacuum" is the absolute lowest energy state, while a "false vacuum" is a local minimum that is not the absolute lowest. The concept of a false vacuum collapse is based on the idea that if our universe currently exists in a false vacuum state, it is not truly stable but only metastable. This means there's a possibility, however minute, that a transition could occur, causing the universe to "fall" into the true vacuum state. Such a transition would propagate through space at the speed of light and fundamentally alter the laws of physics, potentially obliterating all structures in the universe as it goes.This transition could be triggered spontaneously due to quantum fluctuations or by a high-energy event. Once started, it would create a bubble of true vacuum that expands in all directions, converting the false vacuum into the true vacuum.Despite its dramatic implications, it's important to note that this is a highly speculative hypothesis and currently there is no experimental evidence to suggest that our universe is in a false vacuum state. Additionally, even if it were true, the odds of such an event happening within our lifetimes—or within the lifespan of the universe as it has existed so far—are exceedingly low.

What is a phenomenon called "false vacuum collapse"?

as you know :

Mean field energy and bubble formation. The cloud is initially prepared in FV with all atoms in |↑⟩ (A). Although the single spin mode |↓⟩ is lower in energy in the center of the cloud (E↓E↑), the opposite is true in the low-density tails. The interface (domain wall) between ferromagnetic regions with opposite magnetism has positive (kinetic) energy, which is added to the minimum double energy resulting from ferromagnetic interaction. Macroscopic tunneling can occur resonantly in the bubble mode (B), which has a |↓⟩ bubble in the center. The increase in core energy compensates for the cost of domain-wall energy. Crossing the barrier can be caused by quantum fluctuations at zero temperature (full arrow) or by thermal fluctuations at finite temperature (empty arrow). After the tunneling process, the bubble size increases in the presence of dissipation to reach the true vacuum (TV) state (C), without returning to (A). Credit: Nature Physics (2024). DOI: 10.1038/s41567-023-02345-4

An experiment carried out in Italy with theoretical support from the University of Newcastle provided the first experimental evidence of vacuum decay.

In quantum field theory, when a not-so-stable state becomes a true stable state, it is called a "pseudovacuum collapse." This happens through the creation of small local bubbles. While existing theoretical work can predict how often this bubble formation occurs, there is not much empirical evidence.

The Pitaevskii Center for Supercold Atoms Laboratory for the Bose-Einstein Condensation in Trento reports for the first time observations of phenomena related to the stability of our universe. The results are the result of a collaboration between the University of Newcastle, the National Institute of Optics CNR, the Department of Physics at the University of Trento and TIFFA-INFEN and are published in Nature Physics.

The results are supported by theoretical simulations and numerical models, confirming the origin of the decay quantum field and its thermal activation, and opening the way to simulate out-of-equilibrium quantum field phenomena in atomic systems.

This experiment uses a supercooled gas at a temperature less than one microkelvin from absolute zero. At this temperature, the bubbles appear as the vacuum collapses, and Newcastle University's Professor Ian Moss and Dr Tom Billam were able to conclusively show that the bubbles are the result of heat-activated vacuum collapse.

Ian Moss, Professor of Theoretical Cosmology at Newcastle University's School of Mathematics, Statistics and Physics, said: "Vacuum collapse is thought to play a central role in the creation of space, time and matter in the Big Bang, but so far it has not. In particle physics, the decay of the Higgs boson vacuum changes the laws of physics and creates what has been described as the 'ultimate ecological catastrophe'."

Dr Tom Bilam, Senior Lecturer in Applied/Quantum Mathematics, added: "Using the power of ultracold atom experiments to simulate analogues of quantum physics in other systems – in this case the early universe itself – is a very exciting area of research. the moment."

This research opens new avenues in understanding the early universe as well as ferromagnetic quantum phase transitions.

This groundbreaking experiment is only the first step in the discovery of vacuum decay. The ultimate goal is to find vacuum decay at absolute zero temperature, where the process is driven solely by quantum vacuum fluctuations. An experiment in Cambridge, supported by Newcastle as part of the national QSimFP collaboration, is doing just that.

Stam Nicolis added a reply:

Just what the name says: There are many physical systems, whose potential energy, in the absence of fluctuations, possesses more than one minima. If these minima are not degenerate, it can occur that one is the absolute minimum, however, due to the choice of initial conditions, the system is found in another minimum. In the absence of fluctuations, it will stay in the potential well of that minimum.

In the presence of fluctuations, it can occur that the relative minimum is no longer a minimum: In that case the system won't stay there forever and it is possible to compute the rate at which it will evolve to another state.

While the presence of fluctuations is a necessary condition, it isn't sufficient for transitions to be possible.

Sergey Shevchenko added a reply:

“What is a phenomenon called "false vacuum collapse"?”

- the answer to this question is: the question really is absurdity, since really there cannot be fundamentally any “false vacuum”, i.e. that really is an fundamental absurdity, and so its “collapse” is absurdity as well.

Though yeah, in mainstream physics really rather numerous fantastic/mystic “true/false vacuums” really exist, and corresponding publications, where corresponding fantastic/mystic properties and effects of/in the vacuums are “discovered”, are well popular and numerous.

That exists in the mainstream completely logically inevitably from the fact that in the mainstream all really fundamental phenomena/notions, first of all on this case “Matter”– and so everything in Matter, i.e. “particles”, “fundamental Nature forces” – and so “fields”, etc., including “vacuum”, “Consciousness”, “Space”, “Time”, “Energy”, “Information”, are fundamentally completely transcendent/uncertain/irrational,

- and so in every case when the mainstream addresses to something that is really fundamental, the results completely inevitably are only some the fantasies.

More see recent SS post in https://www.researchgate.net/post/What_is_a_super_vacuum_Is_the_earth_in_a_vacuum_And_what_is_dark_energy , and links in the post; reDzennn comment, 9/8 [because of too active moderator] passages, to a Nature Physics (2024) paper in

https://phys.org/news/2024-01-phenomenon-false-vacuum-decay.html) directly relates to the thread question.

Zoltan Vilagosh added a reply:

Not that complicated really. False vacuum example = because you cannot see over the hill, you think are at the lowest level possible. This makes you think you have no potential energy left. But a surprise awaits if you make it to the top of the hill...you tumble lower onto the vast endless plain on the other side.

__/\O/\

\

\__O

Sergey Shevchenko added a reply:

“…Not that complicated really. False vacuum example = because you cannot see over the hill, you think are at the lowest level possible. This makes you think you have no potential energy left. But a surprise awaits if you make it to the top of the hill...you tumble lower onto the vast endless plain on the other side. …..”

- that above looks as tooo not complicated passage really, though, again, on such level the authors of the paper in a top physical Nature Physics (2024) journal also thought,

- which “discovered” “false vacuum bubbles decays” in some Bose-Einstein Cond sate of Na-23 atoms, more see reDzennn comment, 8 passages, in https://phys.org/news/2024-01-phenomenon-false-vacuum-decay.html, the strangely removed by moderator passage is in the end of whole comments series.

Though yeah, the really full stop “false vacuum” theories are rather popular in mainstream physics, including rather popular is the theory that Matter was created soon 14 billion years ago at some “bubble in spacetime decay”. Thank heavens till now no any even small bubbles didn’t decay near Earth, and nowhere in Space at all, in last 10 billion of years Milky Way existence.

However, again, this full stop – and so quite easily composed - fantasies are so rather popular, and in this case so some people don’t like the comment, correspondingly it is heavily “down voted”.

How can we improve computer-brain interfaces for broader and safer use in medicine, research, and daily life?

How to switch to the Ukrainian language of the interface of this site?

Abstract

This research proposal outlines an experimental framework designed to explore the gravitational redshift within the microtubules of neurons. Building on principles derived from atomic physics and quantum mechanics, we aim to bridge the gap between quantum phenomena and biological systems, offering insights into the fundamental nature of gravity's influence on biological structures at the quantum level.

The gravitational redshift is observed in samples as small as one millimeter.1 Gravitational redshift is a phenomenon predicted by the theory of General Relativity. It occurs when light or other electromagnetic radiation emitted from an object in a strong gravitational field is increased in wavelength, or redshifted, as it climbs out of the gravitational well. This effect is observed because, according to General Relativity, the presence of mass curves spacetime, and the path of light follows this curvature. The energy of the light decreases (which corresponds to an increase in wavelength) as it moves away from the source of gravity. This is because, in a gravitational field, time runs more slowly closer to the source of the field. As light moves away from such a source, its frequency appears to decrease to an observer located at a higher gravitational potential. This decrease in frequency translates to a shift toward the red end of the electromagnetic spectrum, hence the term "gravitational redshift."

The magnitude of the gravitational redshift depends on the strength of the gravitational field through which the light is traveling. The stronger the gravitational field (i.e., the closer to a massive body like a planet, star, or black hole), the more significant the redshift. Gravitational redshift has been observed in various astrophysical contexts, including the light coming from the surface of white dwarfs and neutron stars, and it serves as a crucial test for the theories of gravity.

Researching gravitational redshift in neuron microtubules would involve exploring whether gravitational effects within the brain, particularly within microtubules, could influence quantum states in a way that contributes to consciousness or cognitive processes.

Roger Penrose, a mathematical physicist, suggested that quantum gravity could play a role in the collapse of the quantum wave function. In traditional quantum mechanics, the wave function describes a superposition of all possible states of a system. This wave function collapses to a single outcome when observed. Penrose hypothesized that this collapse is not merely a result of observation (as traditionally thought) but can occur spontaneously due to gravitational effects. According to Penrose, when a quantum system reaches a certain level of mass-energy difference between its possible states, the gravitational difference becomes significant enough to cause the system to "choose" a state in a process called "objective reduction" (OR), without the need for an external observer.

This would require linking the microscopic quantum gravitational effects predicted by Penrose23 with the biological structures and functions identified by Hameroff4, an ambitious and highly theoretical endeavor that would bridge physics, neuroscience, and the study of consciousness.

The Orch OR theory is highly speculative and has been met with skepticism by many in the scientific community. One of the main criticisms is the lack of empirical evidence supporting coherent quantum states within the warm, wet environment of the brain, which many argue would lead to rapid decoherence of quantum states.

But that all seemed to change with the results of a recent study where, Polyatomic time crystals of the brain neuron extracted microtubule are projected like a hologram meters away.5

The role of gravitational effects in brain function, particularly in wave function collapse, remains a controversial proposition.

Research Proposal:

Investigating Gravitational Redshift in Neuronal Microtubules

Recent advancements in quantum physics have enabled the precise measurement of gravitational effects on atomic scales, as demonstrated by experiments measuring the gravitational redshift across millimeter-scale atomic samples. Extending these principles to biological systems, particularly neuronal microtubules, presents a novel approach to understanding the intersection of gravity, quantum mechanics, and biology.

Objectives

Methodology

1. Sample Preparation: Neurons will be prepared to isolate microtubules, maintaining their structural integrity.

2. Isolation Mechanism: Utilize magnetic or optical tweezers to stabilize microtubules in a controlled quantum state.

3. Frequency Measurement: Employ advanced spectroscopic techniques to detect minute changes in the vibrational frequencies of microtubules, indicative of gravitational redshift.

4. Data Analysis: Use computational models to analyze frequency shift data, comparing observed effects with theoretical predictions.

Equipment and Tools

Expected Outcomes

The successful execution of this proposal is expected to provide the first measurements of gravitational effects within biological structures at the quantum level, potentially unveiling new insights into the role of gravity in biological processes and quantum biology.

Budget and Timeline

A detailed budget and timeline will be developed, encompassing equipment acquisition, experimental setup, data collection, and analysis phases, projected to span over three years.

Initial Lab Hardware

For your research proposal aiming to measure gravitational redshifts within neuronal microtubules, you would need to integrate advanced optical and magnetic tweezers technologies. These tools are crucial for manipulating and measuring the quantum mechanical properties of microtubules with the precision required to detect such subtle phenomena.

Optical Tweezers

C-Trap® Optical Tweezers: Offered by LUMICKS, these are dynamic single-molecule microscopes that allow for simultaneous manipulation and visualization of single-molecule interactions in real-time. They combine high-resolution optical tweezers with fluorescence and label-free microscopy, integrating an advanced microfluidics system for a comprehensive solution to study molecular dynamics.

Modular Optical Tweezers from Thorlabs: This system provides a tool for trapping and manipulating microscopic-sized objects with a laser-based trap. It includes a high-precision 100X oil immersion objective lens and a 10X air condenser, making it suitable for a range of biological experiments. The system features adjustable force and spot size settings, ensuring precise control over the manipulation of microtubules.

Magnetic Tweezers

Magnetic Tweezers Technology: According to information from Frontiers in Physics, magnetic tweezers are capable of applying forces up to about 20 pN at distances of about 1 mm, using NdFeB magnets and standard beads. This force is sufficient for many single-molecule applications. Magnetic tweezers technology also includes electromagnetic tweezers, which offer efficient feedback loops for stable force clamps and the ability to modulate the strength and direction of the magnetic field with electric current.

Bead Tracking and Force Calibration: Critical for magnetic tweezers, bead tracking in 3D space and force calibration are essential techniques for precise measurements. The technology employs computer programs to track the bead in real-time and uses DNA attachment methods for single-molecule studies, ensuring accurate and reliable data collection.

Acquisition Sources

These tools, combined with your innovative experimental design, aim to unlock new insights into the quantum biological processes within neurons, potentially revolutionizing our understanding of the interplay between gravitational forces and biological structures at the quantum level.

This research has the potential to fundamentally alter our understanding of the interface between gravity, quantum mechanics, and biology, opening new avenues for interdisciplinary research and technological innovation.

If I may add, footnotes for this question: 1

Bothwell, T., Kennedy, C.J., Aeppli, A., et al. (2022). Resolving the gravitational redshift across a millimetre-scale atomic sample. *Nature*, 602, 420–424. https://doi.org/10.1038/s41586-021-04349-7

2

Penrose, Roger. The Emperor's New Mind: Concerning Computers, Minds, and The Laws of Physics. Oxford University Press, 1989. This book presents Penrose's early thoughts on the connection between quantum mechanics, consciousness, and the role of gravity in the wave function collapse, introducing the idea that physical processes could influence consciousness.

3

Penrose, Roger. Shadows of the Mind: A Search for the Missing Science of Consciousness. Oxford University Press, 1994. In this follow-up, Penrose delves deeper into the theory that quantum mechanics plays a role in human consciousness, further developing his hypothesis on objective reduction (OR) and its gravitational basis.

4

Hameroff, Stuart, and Penrose, Roger. "After 20 years of skeptical criticism, the evidence now clearly supports Orch OR." *ScienceDaily*, 2014. https://www.sciencedaily.com/releases/2014/01/140116085105.htm

5

Saxena, Komal, Singh, Pushpendra, Sarkar, Jhimli, Sahoo, Pathik, Ghosh, Subrata, Krishnananda, Soami Daya, and Bandyopadhyay, Anirban. "Polyatomic time crystals of the brain neuron extracted microtubule are projected like a hologram meters away." *Journal of Applied Physics*, vol. 132, no. 19, 194401, Nov. 2022. [https://doi.org/10.1063/5.0130618]

i am trying to make a GUI interface for my modelings but a syntax error are emerged.

how can i solve this error?

GUI codes are attached...

How can one model explosion in a nuclear power plant using comsol multiphysics software? which physics interface are appropriate? which study can be used?

In a well-built apartment building, each apartment has its own walls, and there is an air gap between the walls of adjacent apartments, which provides excellent sound isolation. Could a similar concept provide high-performance thermal insulation?

In general, the thermal resistance of a material interface seems to be viewed as a problem to overcome, rather than an opportunity to create a better insulator (see, eg., https://en.wikipedia.org/wiki/Interfacial_thermal_resistance ). So perhaps it is possible to construct a laminar material that uses inter-laminae thermal impedance to create an extremely high resistance to heat conduction.

As the simplest example of this idea, consider a sheet of material that is composed of a large number of alternating layers of materials A and B. Each of these materials consists of atoms of a single element, and at least one of them is not electrically conductive. Material A has relatively heavy atoms and relatively weak (soft) interatomic bonds; material B has relatively light atoms and relatively strong (stiff) interatomic bonds. The natural modes of vibration in material A have much longer periods than those in B. Thermal vibrations in B layers should essentially reflect off the B/A interface. And, provided that the B layers are not too thin, thermal vibrations in A layers that pass across an A/B interface should largely dissipate into B-style vibrations before reaching the next A layer.

Is it possible to design and fabricate sheets of insulating material, based on this concept, that have exceptionally low thermal conductivity?

what we are working on is studying the friction between two concrete blocks

the bottom one is fixed and the top one is moving back and forth

in the experiments the concrete is deteriorating and the friction is decreasing

how I can model that in software

I tried in Ansys but the material is not deteriorating

I also tried to model it using Movable Cellular automata but I don't know how I will apply rules between the cells

Any Suggestions??

I'm stuck with a meshing challenge in ICEM CFD and hoping someone can point me in the right direction. My model involves two fluid zones:

These zones are connected, and the fluid needs to flow seamlessly from one to the other. However, I'm having trouble creating the interface between them in ICEM CFD.

I've made many attempts by trying to merge the interface of the two zones, but I keep encountering problems in achieving the successful merging of the two zones.

I'd be incredibly grateful if anyone could offer insights or solutions to help me overcome this hurdle. Any advice on:

I've attached a brief visualization of the geometry, to provide further context.

Thank you in advance for your time and expertise!

Sudeep N S

Hi, our team is currently exploring research opportunities regarding visualization tools for computational materials design of inorganic crystal structures. I am writing to ask what features people would like to have for such an interface?

I image such an interface to be something like we start with a chemical composition and we will see the stable phases and corresponding crystal structures. It would also be good if we can know the predicted properties of interest as well as how the structures can be related to the properties. Any thoughts/comments are welcome and appreciated. Thank you.

The current RANS turbulence model requires a Reciprocal Wall Distance variable.

Make sure that all the study steps solving for the flow variables in this physics interface get their initial values of variables not solved for from a study step that has already computed the corresponding Reciprocal Wall Distance variable.

- Node: Turbulent Flow, SST (spf)

thanks in advance

Im having issue interfacing ad4111 with esp32 microcontroller however i tried sending spi commands directly to the ad4111 but. there is something im missing. if anyone have already worked with it or have any idea would help alot.

#embedded_systems #ADC #electronics #SPI

Dear All,

I trying to model heterointerface between two oxides, at first I modeled each surface oxide alone and then I tried to attached OH, O, OOH molecule to find Gibbs free energy. My problem occur when I tried to model the heterointerface. I built my structure using vesta by importing the first unit cell of oxide and enlarge the cell in X and Y direction to fit with the other unit cell of the oxide. I found this procedure is done in some paper to match both lattice parameter. When optimized the oxide alone, the relaxation was not that hard, but when I had an interface between two oxides, the relaxation distort the structure.

I am seeking help in making better structure and relaxation.

This calculation was very costly and I do not want to lose core-hour in the supercomputer.

I appreciate your advice

dear friends

I was trying to study problems with finite friction involving indentation of a thin layer bonded on a substrate. As you can see from the theory

there are large differences between frictionless and infinite friction cases both at punch/layer and layer/substrate interface. However, particularly for incompressible materials, in ANSYS the contact results with finite friction are unreliable and I gave up in trying to setup contact stiffness parameters to find reasonable results --- here we know analytically some limit behaviour for frictionless and very high friction results, so we can check the intermediate case.

Do you think other FEM code could do better? To setup the mesh for the flat punch is extremely simple, so we could try with your help in other codes.

thanks

Mike

When I simulate GaN Transistor, and define the interfaces, s-device simulation fails giving the following message in the log file:

"Turning on fermi and thermionic (TE) should also specify the keyword 'formula=1' in the 'thermionicemission' section of the parameter file, otherwise results can be wrong in higher carrier density cases. in the future, the corrected fermi TE model (formula=1) will become default when using fermi statistics and users are urged to switch to the corrected fermi te model as soon as possible. !"

It also gives "Newton didn't converge. step size is less than min-step" in the (.out file).

Why it fails? is it a mesh problem or the parameter file has a problem ?

Generally, interface polarization disappears at MHz, but why do many literature test frequencies in GHz but interface polarization occurs?

Hey folks!

I'm using TNT version 1.6 for MAC but I can't open my matrix because of this message: "error parsing instructions from graphic interface". I tried to reinstall the software, but it didn't work. Does anyone have an idea what's happening?

Cheers!

I implemented trap on the drift layer of diode with Sentaurus TCAD simulation (it is bulk trap, not interface). How can I measure the concentration of the implemented trap?

How can I effectively model the interface between two sequentially cast layers of Normal concrete in Abaqus, where the first layer (20cm thick) is cast, and the second layer (5cm thick) is poured within an hour before the initial setting of the first layer? Additionally, should I simulate stages of curing and hardening for the Normal concrete material, or is it sufficient to address this through material interaction modelling?

Dear All, I am trying to run the VUMAT-UMAT interface provided on soilmodel.com (https://soilmodels.com/download/vumat_umatinterface-zip/) with the Sand Hypoplasticity. However, when I run the simulation Abaqus returns the following error: “Problem during linking – Single Precision Abaqus/Explicit User Subroutines. This error may be due to a mismatch in the Abaqus user subroutine argument”. The versions of the programs that I am using are: Abaqus 2020, the Visual Studio 2019, and OneAPI compiler v2022. When I run the Abaqus verification, it says PASS for everything (also subroutines), so I assume they are correctly linked. Someone had the same problem and knows how to solve it?

Best regard,

I get an error when I try to compile the * .sln file in VS 2019, after being generated by the Cmake interface.

My error output is:

"Compile operation started: project: release-version-info, configuration: Debug x64 ------

1> Generating release version information

1> - The source code for this GROMACS installation is different from the officially released version.

2> ------ Compile operation started: project: libgromacs, configuration: Debug x64 ------

2> Building NVCC (Device) object src / gromacs / CMakeFiles / libgromacs.dir / nbnxm / cuda / Debug / libgromacs_generated_nbnxm_cuda.cu.obj

2> nvcc fatal: Unknown option '-std: c ++ 17'

2> CMake Error at libgromacs_generated_nbnxm_cuda.cu.obj.Debug.cmake: 224 (message):

2> Error generating

2> C: /Users/USUARIO/Downloads/gromacs-2021.2/build/src/gromacs/CMakeFiles/libgromacs.dir/nbnxm/cuda/Debug/libgromacs_generated_nbnxm_cuda.cu.obj

2>

2>

2> C: \ Program Files (x86) \ Microsoft Visual Studio \ 2019 \ Community \ MSBuild \ Microsoft \ VC \ v160 \ Microsoft.CppCommon.targets (241.5): error MSB8066: Custom build of "C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ nbnxm \ cuda \ nbnxm_cuda.cu; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ nbnxm \ cuda \ nbnxm_cuda_data_mgmt.cu; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ nbnxm \ cuda \ nbnxm_cuda_kernel_F_noprune.cu; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ nbnxm \ cuda \ nbnxm_cuda_kernel_F: USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ nbnxm \ cuda \ nbnxm_cuda_kernel_VF_noprune.cu; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ nbnxm \ cuda \ nbnxm_cuda_prune_cu; C: USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ nbnxm \ cuda \ nbnxm_cuda_kernel_pruneonly.cu; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ domdec \ gpuhaloexchange_impl.cu; C: \ Users \ USUARIO Downloads \ gromacs-2021.2 \ src \ gromacs \ utility \ cuda_version_information.cu; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ mdlib \ leapfrog_gpu.cu; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ mdlib \ lincs_gpu.cu; C: \ Users \ USUARIO \ Downloads \ gromacs-2021.2 \ src \ gromacs \ mdlib \ settle_gpu.cu; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ mdlib \ update_constrain_gpu_impl.cu; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ mdlib \ gpuforcereduction_impl.cu; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ listed_forces \ gpubonded_impl.cu; C: \ Users \ USUARIO \ Downloads \ gromacs-2021.2 \ src \ gromacs \ listed_forces \ gpubondedkernels.cu; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ nbnxm \ nbnxm_gpu_data_mgmt.cpp; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ ewald \ pme_ .cu; C: \ Users \ USUARIO \ Downloads \ gromacs-2021.2 \ src \ gromacs \ ewald \ pme_gpu_3dfft.cu; C: \ Users \ USUARIO \ Downloads \ gromacs-2021.2 \ src \ gromacs \ ewald \ pme_solve.cu; C : \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ ewald \ pme_spread.cu; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ ewald \ pme_gpu_program_impl.cu; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ ewald \ pme_pp_comm_gpu_impl.cu; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ ewald \ pmeg_force_force_sender. cu; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ ewald \ pme_coordinate_receiver_gpu_impl.cu; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ ewald \ pme_gpu_internal.cpp; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ ewald \ pme_gpu_timings.cpp; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ gpu_utils \ device_stream_manager.cpp; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ gpu_utils \ device_stream.cu; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ gpu_utils \ gpu_utils.cu; C: \ Users \ USER \ Downloads \ gromacs -2021.2 \ src \ gromacs \ gpu_utils \ pinning.cu; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ gpu_utils \ pmalloc_cuda.cu; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ hardware \ detecthardware.cpp; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ h ardware \ device_management_common.cpp; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ hardware \ device_management.cu; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ src \ gromacs \ mdtypes \ state_propagator_data_gpu_impl. cpp; C: \ Users \ USER \ Downloads \ gromacs-2021.2 \ build \ CMakeFiles \ a9116bcf4bc4115e626ce4c6578cc5c1 \ baseversion-gen.cpp.rule "terminated with code 1.

2> Compilation of project "libgromacs.vcxproj" finished - ERROR.

3> ------ Compile operation started: project: gmx, configuration: Debug x64 ------

3> LINK: fatal error LNK1104: cannot open file '.. \ .. \ lib \ Debug \ gromacs.lib'

3> Compilation of project "gmx.vcxproj" finished - ERROR.

========== Compile: 1 correct, 2 incorrect, 15 updated, 0 skipped ========== ".

I have CUDA 11.4, Win 10 64bit and FFTW 3.3.5 installed. I would be very grateful if you could guide me in solving this error, as I wish to be able to compile on my own any new version of Gromacs on Windows that might be released in the future.

A special issue of Nanomaterials (ISSN 2079-4991).

Deadline for manuscript submissions: 20 February 2024

Special Issue Information

Dear Colleagues,

In the face of major national scientific and technological needs, aiming at the national "double carbon" and "rural revitalization" strategic goals, the environmental application and technological innovation breakthrough of new functional engineering nanomaterials for water pollution control is an important scientific and technological guarantee to fight the battle for blue water. It is important to build new methods and principles for the efficient purification of new pollutants based on solar energy and atmospheric oxygen and other green energy sources; to reveal the interaction mechanism of the three elements of process, effectiveness and mechanism of environmental chemistry of new pollutant control; to clarify the influence law and principle of action of interface characteristics and process parameters on the control of new pollutants; to quantitatively establish the structure–effect relationship of the surface interface from the microscopic scale; to solve the bottleneck problems of catalytic activity abatement, selectivity and poor stability; and to form a long-term mechanism of new pollutant treatment.

Dr. Huinan Che Dr. Runren Jiang Guest Editors

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Nanomaterials is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2900 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

Published Papers

This special issue is now open for submission.

Is it just a theoretical concept? If so, how is it modeled? Is it a consequence of poor physical contact?

How can I calculate normal and shear stiffness of interface between the FRP ,epoxy resin and concrete ?

 I am using DIANA for it. Please suggest me.

I was trying to create a FEM model of an LVI and CAI experiment. For the CAI simulation, the load displacement curve I obtained is way too stiff compared to the experimental result. The maximum compression load is already quite similar with the experiment. Is there parameters that I can change to reduce the compressive stiffness ?

The simulation model was created in the ABAQUS Explicit solver. The composite plate is divided into 16 layers of laminate and 15 layers of interfaces. Each layer of laminate and interface have thickness of 0.215 mm and 0.025 mm respectively. The laminate was meshed with SC8R and use the Hashin damage model. The interface layer is modelles using COH3D8 elements and the QUADS damage criterion and energy based Benzeggah damage evolution.

When I used Diana to build a two-dimensional micro-modeling, I did not know where to set the constraint of the boundary interface. There were problems in the properties of the interface materials between each brick and between masonry brick and frame.

Reservoir Engineering

1. Feasible to capture the transition between (a) and (b) @ laboratory-scale?

(a) where, an oil phase gets disconnected into blobs (and remain strongly influenced by local pressure field near a flood front, which mostly remain to be transient - even in a steady-state displacement process); and remain trapped and the way the oil/water menisci gets migrated @ pore-scale;

(b) where, continuous mobility of water/oil/gas phases occur @ macroscopic-scale, where averaged quantities are both interpolated as well as extrapolated?

2. If displacement of oil from water-wet porous sedimentary rock by water-flooding leads to an entrapment of a considerable fraction of oil, then,

would it remain feasible to capture the role of buoyancy and inertial forces in addition to the interplay between capillary and viscous forces @ laboratory-scale?

3. If pore-level displacement is initiated by an externally imposed flow, then, how exactly to capture the complex interplay between local topology and pore-scale geometry with capillarity along with the complex interplay between buoyancy, inertial and viscous forces?

Even, if we manage to capture such complex physics, how could we capture the spontaneous rupture of an oil neck (choke-off) and its associated spontaneous withdrawal of head meniscus out of a pore body @ lab-scale?

4. Can we deduce the details on the length distribution of blobs towards determining the oil recovery efficiency upon mobilizing the entrapped oil blobs by lowering IFT @ lab-scale?

If each curved meniscus supports a difference in oil and water pressure resulting from its associated IFT, then, would it remain feasible to distinguish the interface between oil and water within a water-wet reservoir into zones that consists of a meniscus which essentially obey Young-Laplace equation of capillary hydrostatics; and those zones that connect the menisci (zones of positive/negative Gaussian curvatures associated with the menisci of oil-water interface) @ laboratory-scale?

If so, how exactly the physics of thin films along with capillary hydrostatics will be up-scaled to Darcy-scale?

5. In EOR applications, whether any meniscus would be able to move by spontaneously developing excess capillary pressure that would cause oil to flow?

6. Feasible to ensure that a jump (when a pore body gets evacuated of oil and filled with water) remains more likely to be upstream than downstream, which would make the displacement front more stable, while oil entrapment remaining less frequent @ lab-scale?

7. If displacement of oil or any non-wetting fluid from an initially saturated porous medium by water or any wetting fluid consists of advancement of head menisci (jumps); consequent break-offs and choke-offs of neck menisci; and creation of isolated oil or non-wetting fluid blobs in the process, which remain to be deterministic and reproducible, then, can we replicate the above physics @ lab-scale?

Hi,

I am modeling a reinforced concrete(RC) slab in DIANA FEA.

The RC slab is simply mounted on a steel girder (see config 1) Therefore, there is no bonding between the RC slab and the steel girder. In order to satisfy these interface conditions, it is set as shown in Figure 2. When a vertical downward pressing force (bending stress) from the center of the slab is applied, it is expected that the slab located on the girder will be lifted up (as in the principle of lever). See Fig 3). As expected, the upward displacement of the slab on the girder occurred, but in some sections it appeared as if it had been bonded and no lifting occurred (See Figure 4) Please advise why this is happening and what interface setting should be done.

Thank you.

For a single layer anti-reflective coating, people generally say if the layer thickness is λ/4, the reflection could reduce and transmission increase.

As the figure, because the light was reflected by second interface and therefore there was additional optical path of λ/2, resulting destructive interference of reflection. Because 1-F(reflection)=T(transmission) ; so T increases.

However, if we think the transmission in the same way. The destructive interference of transmission also happens, doesn't it? How could we say the transmission increase?

If anyone is familiar with anti-reflective coating? Please help me. THANKS!

Hey there! I would like to conduct an event study with the buy-and-hold approach and that website was suggested to me. It talks about long run event studies but I could not find it on the ARC interface and I was wondering if it is there and I am just missing it. Thank you very much!

I really need an idea on new work to start.

Dear colleagues,

We recently purchased a cable to synchronise the different signals from the Biodex System 3 isokinetic through a PowerLab 8/35 DAQ and LabChart software (ADInstruments). After thorough testing, we have not been able to get the signals to appear in the software. Please, find attached the information of the cable characteristics we followed.

We contacted Biodex (USA and Spanish providers) and they told us that it was necessary to have a tool installed on the computer called Analog Signal Access Interface (ASA Utility)(https://www.biodex.com/physical-medicine/products/software-updates/legacy-software/analog-signal-access-interface).

However, they told us that everything related to the System 3 model was discontinued and they could not provide us with this software.

We would like to kindly request, if possible, if you could share with us a digital copy of the installation file of the ASA Utility. If not, we would like to know if you know of any other possible solution to this problem.

Thank you very much for the attention and help.

Hello,

I'm working on simulating 3D VIV with ANSYS FLUENT. To start with easy point, I made the cylinder static, but Karman Vortex Street just didn't show up. The fluid domain was separated into inner region (finer meshes) and outer region (coarser meshes). And I noticed that the quantities crossing the interface of 2 regions was discontinuous as the pic shows. I tried different combinations of mesh types, but it came out the same.

Does anyone know the answer?

Note that the interface of 2 regions is non-conformal, and Matching was selected in Interface Options panel.

Please help me, thanks a lot!

As to the title, I have computed a gas-liquid two-phase flow by "laminar-flow,level-set ". I wish to get the velocity of the head of the bubble vs. time, i.e., the velocity of the interface(phils=0.5). How could i get this velocity? Thanks a lot.

It is possible to read the acceleration values from the microcontroller above? I have been struggling as the datasheet didn't explain this or because I am a novice