Can you describe what this term means?...

[Lamont Cranston]

I don\'t know what the th is in the expression f/fth.

\"The rate of coalescence in AC field is characterized by a sharp threshold frequency. At f/fth there is no coalescence, whereas at f/fth coalescence depends on magnitude as well as frequency of the applied field.\"
Thanks, Mikek

P.S. Even if I understand the term, I\'m not sure the sentence make sense!

 

[legg]

On Fri, 19 May 2023 04:52:47 -0700 (PDT), Lamont Cranston
<amdx62@gmail.com> wrote:

I don\'t know what the th is in the expression f/fth.

\"The rate of coalescence in AC field is characterized by a sharp threshold frequency. At f/fth there is no coalescence, whereas at f/fth coalescence depends on magnitude as well as frequency of the applied field.\"
Thanks, Mikek

P.S. Even if I understand the term, I\'m not sure the sentence make sense!

Out of context, it means nothing.

Check the article to see if there\'s a list of terms/defns,
or if fth shows up is placed in earlier paragraph where
its sense is made clear.

RL

 

[John Larkin]

On Fri, 19 May 2023 04:52:47 -0700 (PDT), Lamont Cranston
<amdx62@gmail.com> wrote:

I don\'t know what the th is in the expression f/fth.

\"The rate of coalescence in AC field is characterized by a sharp threshold frequency. At f/fth there is no coalescence, whereas at f/fth coalescence depends on magnitude as well as frequency of the applied field.\"
Thanks, Mikek

P.S. Even if I understand the term, I\'m not sure the sentence make sense!

It doesn\'t.

Where did that nonsense come from?

 

[Wandere]

th means threshold. It is a subscript for f as in f threshold. Also your quote is wrong.

https://www.sciencedirect.com/science/article/pii/S0263876215000453

In the presence of dissolved salts in water, the rate of coalescence in AC field is characterized by a sharp threshold frequency (f th) (Szymborski et al., 2011). At f > f th there is no coalescence, whereas at f < f th coalescence depends on magnitude as well as frequency of the applied field.

 

[Lamont Cranston]

On Friday, May 19, 2023 at 8:44:45 AM UTC-5, Wanderer wrote:

th means threshold. It is a subscript for f as in f threshold. Also your quote is wrong.

https://www.sciencedirect.com/science/article/pii/S0263876215000453

In the presence of dissolved salts in water, the rate of coalescence in AC field is characterized by a sharp threshold frequency (f th) (Szymborski et al., 2011). At f > f th there is no coalescence, whereas at f < f th coalescence depends on magnitude as well as frequency of the applied field.

This quote is from a listof quotes my son made of things he thought might be relevant to his experiment.
Wanderer is correct, the \'quoter\' my son somehow mixed up / when it should have been <.
Maybe copy/paste didn\'t work with f<fth and when he fixed it he mistyped /.. I\'ll have to ask. I know he didn\'t type 3 pages of quotes.

Still not sure I understand, threshold would seem to be a sweat spot frequency and when the frequency is above fth there is no coalescence,
while below fth there is coalescence but dependent on magnitude as well as frequency of the applied field.
I\'m not sure I have the threshold frequency defined correctly.
Thanks for your input, Mikek

 

[boB]

On Fri, 19 May 2023 09:42:06, Wanderer<dont@emailme.com> wrote:

th means threshold. It is a subscript for f as in f threshold. Also your quote is wrong.

https://www.sciencedirect.com/science/article/pii/S0263876215000453

In the presence of dissolved salts in water, the rate of coalescence in AC field is characterized by a sharp threshold frequency (f th) (Szymborski et al., 2011). At f > f th there is no coalescence, whereas at f < f th coalescence depends on magnitude as well as frequency of the applied field.

Looking at an article about electrostatic phase separation (this
context ?), I also made the assumption that fth was threshold
frequency.

boB

 

[Lamont Cranston]

On Friday, May 19, 2023 at 12:15:56 PM UTC-5, boB wrote:

On Fri, 19 May 2023 09:42:06, Wanderer<do...@emailme.com> wrote:


th means threshold. It is a subscript for f as in f threshold. Also your quote is wrong.

https://www.sciencedirect.com/science/article/pii/S0263876215000453

In the presence of dissolved salts in water, the rate of coalescence in AC field is characterized by a sharp threshold frequency (f th) (Szymborski et al., 2011). At f > f th there is no coalescence, whereas at f < f th coalescence depends on magnitude as well as frequency of the applied field.
Looking at an article about electrostatic phase separation (this
context ?), I also made the assumption that fth was threshold
frequency.

boB

I\'m not sure of the definition of threshold frequency.
The lit is kinda all over, some say 11Hz is optimum, others say HF (1000Hz?) Some say AC is better than DC pulse, and Vise Versa.
I see no mention of the Actual Threshold frequency, it could very well be that threshold frequency is dependent on the
ratio of oil/water. water/oil emulsion and also the type of oil.
Mikek

 

[Jasen Betts]

On 2023-05-19, Lamont Cranston <amdx62@gmail.com> wrote:

On Friday, May 19, 2023 at 12:15:56 PM UTC-5, boB wrote:
On Fri, 19 May 2023 09:42:06, Wanderer<do...@emailme.com> wrote:


th means threshold. It is a subscript for f as in f threshold. Also your quote is wrong.

https://www.sciencedirect.com/science/article/pii/S0263876215000453

In the presence of dissolved salts in water, the rate of coalescence in AC field is characterized by a sharp threshold frequency (f th) (Szymborski et al., 2011). At f > f th there is no coalescence, whereas at f < f th coalescence depends on magnitude as well as frequency of the applied field.
Looking at an article about electrostatic phase separation (this
context ?), I also made the assumption that fth was threshold
frequency.

boB

I\'m not sure of the definition of threshold frequency.
The lit is kinda all over, some say 11Hz is optimum, others say HF (1000Hz?) Some say AC is better than DC pulse, and Vise Versa.
I see no mention of the Actual Threshold frequency, it could very well be that threshold frequency is dependent on the
ratio of oil/water. water/oil emulsion and also the type of oil.
Mikek

Threshold frequency is almost certainly dependant on what is being
measured with respect to frequency. withcout concrete context it is
meaningless.

--
Jasen.
🇺🇦 Слава Україні

 

[Ricky]

On Friday, May 19, 2023 at 1:53:03 PM UTC-4, Lamont Cranston wrote:

On Friday, May 19, 2023 at 12:15:56 PM UTC-5, boB wrote:
On Fri, 19 May 2023 09:42:06, Wanderer<do...@emailme.com> wrote:


th means threshold. It is a subscript for f as in f threshold. Also your quote is wrong.

https://www.sciencedirect.com/science/article/pii/S0263876215000453

In the presence of dissolved salts in water, the rate of coalescence in AC field is characterized by a sharp threshold frequency (f th) (Szymborski et al., 2011). At f > f th there is no coalescence, whereas at f < f th coalescence depends on magnitude as well as frequency of the applied field.
Looking at an article about electrostatic phase separation (this
context ?), I also made the assumption that fth was threshold
frequency.

boB
I\'m not sure of the definition of threshold frequency.
The lit is kinda all over, some say 11Hz is optimum, others say HF (1000Hz?) Some say AC is better than DC pulse, and Vise Versa.
I see no mention of the Actual Threshold frequency, it could very well be that threshold frequency is dependent on the
ratio of oil/water. water/oil emulsion and also the type of oil.
Mikek

I\'m pretty sure there will not be a single, universal threshold frequency. That will depend on the details of your mixture and the apparatus. I think the references are simply explaining that the threshold exists, and they seem to say it is \"sharp\", so not entirely unlike the response curve of a filter.

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

 

[Martin Brown]

On 19/05/2023 23:44, Jasen Betts wrote:

On 2023-05-19, Lamont Cranston <amdx62@gmail.com> wrote:
On Friday, May 19, 2023 at 12:15:56 PM UTC-5, boB wrote:
On Fri, 19 May 2023 09:42:06, Wanderer<do...@emailme.com> wrote:


th means threshold. It is a subscript for f as in f threshold. Also your quote is wrong.

https://www.sciencedirect.com/science/article/pii/S0263876215000453

In the presence of dissolved salts in water, the rate of coalescence in AC field is characterized by a sharp threshold frequency (f th) (Szymborski et al., 2011). At f > f th there is no coalescence, whereas at f < f th coalescence depends on magnitude as well as frequency of the applied field.
Looking at an article about electrostatic phase separation (this
context ?), I also made the assumption that fth was threshold
frequency.

boB

I\'m not sure of the definition of threshold frequency.
The lit is kinda all over, some say 11Hz is optimum, others say HF (1000Hz?) Some say AC is better than DC pulse, and Vise Versa.
I see no mention of the Actual Threshold frequency, it could very well be that threshold frequency is dependent on the
ratio of oil/water. water/oil emulsion and also the type of oil.
Mikek

It will be sensitive to both the proportion of oil and water and the
size of the oil particles. You could try measuring how much power you
are delivering into the system as a way of optimising it.

(that could also be misleading but it would be a start

Threshold frequency is almost certainly dependant on what is being
measured with respect to frequency. withcout concrete context it is
meaningless.

f_th (in Tex notation) it\'s meaning from the context is threshold
frequency. I don\'t know what it is in this system but it is likely to be
related to the separation of the particles in the emulsion, their size
distribution and the amount of electric field applied.

To get them to coalesce you need to bang them together and as you do so
there are then fewer bigger particles further apart. My instinct is that
f_th will fall as the suspension begins to separate.

Almost all colloidal systems have some critical behaviour when the
suspension reaches a critical density and so a suspension of small
conducting balls will snap from being an insulator to being a conductor
as the concentration of particles is slowly increased.

--
Martin Brown

 

[Lamont Cranston]

On Monday, May 22, 2023 at 3:12:47 AM UTC-5, Martin Brown wrote:

I\'m not sure of the definition of threshold frequency.
The lit is kinda all over, some say 11Hz is optimum, others say HF (1000Hz?) Some say AC is better than DC pulse, and Vise Versa.
I see no mention of the Actual Threshold frequency, it could very well be that threshold frequency is dependent on the
ratio of oil/water. water/oil emulsion and also the type of oil.
Mikek

It will be sensitive to both the proportion of oil and water and the
size of the oil particles. You could try measuring how much power you
are delivering into the system as a way of optimising it.

We were measuring power, up until the last iteration of 8 output voltages to be used with 4 test at 4 different voltages.
Ideally we would measure each vessel, that is a bit unwieldy.
Yes, we have found different oils have different capacitance, and I have told my son to measure and record
every type of emulsion that he tests, as this may be a way to correlate, what power, frequency, AC, DC pulse, or even duty cycle is optimum.

(that could also be misleading but it would be a start

Threshold frequency is almost certainly dependant on what is being
measured with respect to frequency. withcout concrete context it is
meaningless.
f_th (in Tex notation) it\'s meaning from the context is threshold
frequency. I don\'t know what it is in this system but it is likely to be
related to the separation of the particles in the emulsion, their size
distribution and the amount of electric field applied.

To get them to coalesce you need to bang them together and as you do so
there are then fewer bigger particles further apart. My instinct is that
f_th will fall as the suspension begins to separate.

Almost all colloidal systems have some critical behaviour when the
suspension reaches a critical density and so a suspension of small
conducting balls will snap from being an insulator to being a conductor
as the concentration of particles is slowly increased.

We have seen some increase in current flow as coalescence happens and contaminated water
falls to the bottom. I don\'t know how significant that was, and hopefully he will get back to measuring that.
Thanks, Mikek

--
Martin Brown