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bio website akhmeteli.org
location Houston, TX
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visits member for 2 years, 10 months
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4h
answered Positron discovery history
Nov
19
answered Does the conductivity of a wire in a vacuum decrease over time?
Nov
18
awarded  Revival
Nov
15
comment How to chose right lens for concentrating IR signal?
What is the wavelength?
Nov
14
answered Why does my measured I-V curve for a film of aluminum suggest high resistance?
Nov
12
answered Build a ring around Earth, then remove the supports
Nov
11
revised “Bump and Go” toy car mechanism
Addition to take into account OP's comment
Nov
11
answered “Bump and Go” toy car mechanism
Nov
1
answered Is it possible to eliminate Van der Waals interactions?
Nov
1
comment Adding a tracer to the surface of a water droplet
@Hossein: 1. Because gravity does not cause relative motion of the droplet and the particle in weightlessness of free fall. 2. By using smaller particles (see below). 3. They will remain on the surface if covered by a surfactant making them hydrophobic - due to surface tension (you know that some insects walk on water). They will not go down along the droplet surface (or will go down slowly) if they are small enough, so volume effects, such as gravity, will be less important than surface effects, such as air drag (you know that aerosols fall slowly in air).
Nov
1
answered Adding a tracer to the surface of a water droplet
Oct
29
answered The Debye temperature for diamond
Oct
29
comment How to prevent water droplets becoming larger on the tip of a nozzle?
@Meriam: my reasoning was the surface tension force is greater if the droplet neck is large, and it is not obvious the neck diameter is defined by the inner diameter.
Oct
29
answered How to prevent water droplets becoming larger on the tip of a nozzle?
Oct
26
comment Confusion about the Definition of Boiling Point
@Yandle: 1. I see... maybe I am wrong, but I thought 100%RH means the water vapor is saturated. OK. then if you increase the temperature without adding some water, the vapor (or the air:-) ) becomes unsaturated. 2. If you have no atmosphere, you have vacuum (if we do not count water vapor). It is difficult to pump out all air.
Oct
26
comment Confusion about the Definition of Boiling Point
@Yandle: 1. I don't understand that - as far as I remember, there cannot be saturated air other than at very low temperatures. 2. en.wikipedia.org/wiki/Ultra-high_vacuum
Oct
26
comment Confusion about the Definition of Boiling Point
@Yandle: I guess one "reason why boiling typically implies the presence of an atmosphere" is it is difficult (if not impossible) to achieve full vacuum.
Oct
26
comment Confusion about the Definition of Boiling Point
@Yandle: I guess there can be more than one differing factor, but, in particular, the vapor pressure under the piston will always be saturated (in equilibrium).
Oct
26
comment Confusion about the Definition of Boiling Point
@Yandle: The presence of atmosphere does have effect on the boiling mechanism, for example, through its pressure. I believe, however, that "we will still see nucleation/bbubles even under a pressure controlled homogeneous environment", as there are vapor bubbles (scienceline.ucsb.edu/getkey.php?key=3197 )
Oct
26
answered Confusion about the Definition of Boiling Point