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# Phase - Science topic

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metal carbide and nitride specly 4 5 6 group transition metal carbides and nitride.
Visit kindly the following useful RG link:
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I want to simulate the plasticity for the Ti and its alloys with two phases (Alpha and Beta) in Abaqus. Now I have already created the microstructure model but unsure what properties I should assign to its two constituent phases, namely alpha and beta, as I only know the bulk material parameters (e.g., Ti-10Mn)?
Alpha and beta are part of Ti-8Mn; the only difference I see is that one will be HCP while the other the BCC structure, so how do I create such a material?
I assume you are using some kind of crystal plasticity model.
You can find parameters for the alpha phase here:
and see the crystal plasticity implementation here:
In crystal plasticity, you will need to use two different material models for the two phases. Normally in Abaqus you would define two different user materials and assign them to the different grains representing different phases (sections of the geometry).
Best Regards,
Nicolò Grilli
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The term "phase" is always a confusing thing for me. When we recoding images, we say that we have recorded the amplitude and phase. Amplitude I am able to relate/ physically understand by connecting with intensity. As, intensity increases, the amplitude will also increase. But the phase term is still I am not able to digest. I am not able physically understand the phase term, like understand the amplitude term. Can anyone explain this?
I have studied the mathematics of Phase. But I am not able to physically relate it.
A gradient in the refractive index affects the (relative) phase of an x-ray beam, which is evaluated by appropriate interferometric techniques. A 2D representation of the differential phase distiribution is called the differential phase image...
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Dear all,
I am trying to find a way to find dispersion curves of plates using Rayleigh-Lamb frequency equations. I used a repetitive procedure by sweeping through the frequencies and inside it increasing the phase velocity incrementally to find the roots of the equation.
In each frequency, there is some roots of phase velocity. As symmetric and asymmetric equations are already separated it is easy to separate data points of the two different waves. However, at the end of the process we have just (W frequency , Cp phase velocity) datapoints and after plotting the result we can see the behavior of the curves to manually define the mode number.
Main question: One way of clustering the data to different modes is to sweep through the data and define the first Cp as the mode zero, the second one as 1st mode and so on.
1. What if we had a crossing between curves?
2. I got some identical roots derived from both symmetric and asymmetric equations. How can one distinguish these datapoints correctly for the type of wave they belong?
Mohsen
Dear Mohsen,
The explanations provided here may be helpful.
I try to identify the origin of the crossing between symmetric and antisymmetric modes in transverse isotropic magneto-electro-elastic composite using the slowness curves and the modal shape.
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Are both the phases crystallographically same? Can WSexist in both the phases or not?
The transition metal is surrounded by chalcogen atoms and forms the structure like trigonal prism. Another form is the metallic 1T phase in which transition metal is synchronized by chalcogen atoms octahedrally. A distorted version of 1T phase is refer as 1T’ phase, in this structure transition metal atoms are just about octahedrally synchronized by chalcogen atoms but with less symmetry. The 2D lattice of the 2H and 1T single layers is hexagonal but the 2D lattice of 1T’ monolayer is rectangular. Phase change occurs from the 2H to 1T take place between 820 C and 880 C . Once the transition into 1T-phase occurs, this arrangement continues it’s meta-stable at high temperature without changing back into the 2H-phase. Above 1100 C it converted into 1T’ phase.
Yes WS2 can represents it self in both phases.
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I have been trying to make cubic BaTiO3 nanoparticles in ambient conditions but could not do so. The solid-state route that I tried ended up melting and sticking of BaCO3 powders in the crucible. I am not able to find some convenient chemical route either for making these cubic BaTiO3 nanoparticles. Please also suggest a way to get dense ceramic (I mean sintering parameters) out of these cubic BaTiO3 nanoparticles.
Dear Dr. Lakshaman Kumar,
in addition to the useful and interesting information provided by Dr. Abdelkader BOUAZIZ , I suggest you to have a look also at the following papers:
-A Modified Method for Barium Titanate Nanoparticles Synthesis
R. Ashiri, Ali Nemati, M. Sasani Ghamsari, S. Sanjabi, M. Aalipour
Materials Research Bulletin, 46 (2011) 2291–22952292
-Low-temperature synthesis of crystalline BaTiO3nanoparticles by one-step “organosol”-precipitation
Yanling Gao, Vladimir V. Shvartsman, Anna Elsukova and Doru C. Lupascu
J. Mater. Chem., 22, 17573-17583 (2012)
-Synthesis of highly disperse tetragonal BaTiO3 nanoparticles with core–shell by a hydrothermal method
Jinhui Li, Koji Inukai, AkihiroTsuruta, YosukeTakahashi, WoosuckShin
Journal of Asian Ceramic Societies, Vol. 5, Issue 4, Pages 444-451 (2017)
Best regards, Pierluigi Traverso
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IRS modify the phase and Backscatter device adjust the reflection coefficient. Backscatter device can modulate its information symbols over incident carriers by intelligently changing its load impedance and IRS can also modulate its own information. So, how they are different from each other ?
IRS is getting a gradually wider meaning. Many people are considering the use case when the IRS acts as a relay that support the transmission from a source to a destination, by configuring how it reflects the incident signals towards the destination.
But if the IRS is also trying to convey its own information, by encoding it into how it varies the reflection properties over time, then it also performs backscattering communications.
So the topics are overlapping. Some people might say that backscattering is a special case (or use case) of IRS technology. Others might say that IRS technology is capable of performing backscattering communication, as an add-on to its primary use cases.
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I was trying to research about an automatic phase splitter project for 3 phase induction motor but Google will give me results for automatic phase inverters. When i tried to find the definition, it confused me and i couldn't point out their difference.
If you study the differences in phase splitter and phase inverters, the idea belongs to audio amplifier (http://www.angelfire.com/electronic/funwithtubes/Amp-Phase.html) , but you are doing something for the induction motor, so in my opinion you concentrate on the problem. Now a days, all of this is done through Power-bridge circuits(https://en.wikipedia.org/wiki/H_bridge), and the idea of changing phase through phase splitter is gone, unless you have a very big load.
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I have read that to know the composition of different phases in a ternary phase diagram of metals A,B,C (at a particular temp. T), we can apply lever rule along the tie line. But, I am not sure about how to draw the tie line and how to apply lever rule along it as some procedure says to use line and few have mentioned smaller triangles to draw (tie-triangles) to know the composition of the phases. Kindly illustrate on the concept. Thanks in advance for help.
Unfortunately, you can not predict those tie lines that you see in ternary phase diagrams, they are experimentally determined by different techniques depending on what kind of sample you have (NMR spectroscopy, low-angle x-ray scattering and etc...). Usually, when the two phases region is determined, the tie lines are determined as well. I think your question was: can i draw the tie limes (by geometry or any other mathematical means) if i know the limits of the two phases region? The answer is no, those lines are experimentally determined by analyzing the composition of the two phases.
For example, if you know the limits of the two phases, what you do is take many samples inside the two phases region and determine analytically the composition of each phase: if you have one phase with 25% of A, 50% of B and 25% of C and the other phase with 60% of A, 30% of B and 10% of C, you now have two points that can be connected to form one tie line.
Once you have sufficiently tie lines inside your two phases region, other tie lines can be predicted (conjugate lines).
Best,
Thiago.
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I obtain the image attached when using an in-house design with a Taqman probe. The template is a synthetic DNA. Which could be the problem?
As Dr. Laura said it is clearly noted in picture the correction baseline is lower than it should be, also the partially degraded probe as well mentioned.
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What are the difference between the crystal structure, lattice parameters, and wyckoff positions of atoms in X2YZ system in L21 and B2 phases?
You can follow
• DOI: 10.1007/s10948-015-3149-8
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A photon is a wave-packet which can be Fourier expanded as
(1) Σp exp[i(pr - Et)/ħ]
The phase velocity, i.e. the velocity of propagation of the phase, is obtained for each Fourier component by requiring
(2) φp = (pr - Et)/ħ = const.
Taking the time derivative one gets pdr/dt = E , i.e. the well-known relation,
(4) pvφp = E.
The phase velocity vφp is not the same for all the Fourier components, some of them propagate more quickly and some more slowly. Some propagate faster than c, some are slower than c, leading to the dispersion of the wave-packet after some time. The universal constant c is the group velocity, not the phase velocity.
WHY the group velocity has more physical significance than the phase velocity? And why all the photons have the same group velocity, c?
There is another nice way to visualize high phase velocities..assume you are standing on a beach and the (water) waves are coming with some shallow angle to the beach..then the speed of propagation of those water waves (which for water waves depends on the depth of the water) can be seen as a kind of group velocity but the speed with which the wave breaking front is running up the beach is a phase velocity.The phase velocity is something very clearly physical and can easily be measured (e.g via standing wave pattern in a waveguide) but also in acoustics. And what you teacher told you that the PHASE velocity near an antenna may exceed the speed of light is absolutely correct similar to the situation at a waveguide below cutoff.BUT there are many claims that also the group velocity in such cases exceeds v=c which can easily be "demonstrated" but one should be very careful before interpreting this as signal velocity (V>c) since it usually violates the underlaying approximation or condition to use that simple definition only for weak dispersion.
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I have another question regarding the relation between the thickness of the substrate and reflection phase of FSS.I have observed different results for different thickness i.e. the thickness of 1.6mm phase is changing  +180 to -180 and extends more than -200 by adding the phase progressively, whereas with the thickness of 0.8mm it is changing from +180 to +100  and then suddenly rises to +235 degrees at the resonance frequency.Then after again decreasing as the frequency increases,  but overall this value is having positive phase.
Can anyone explain the reason?
I recommend you to read this paper:
Best regards
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Bandgap=1.74eV is for which phase of CdSe?
It is 1.74 eV at room temperature for both the phases. Link of the reference is attached here.
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how to bring metallized spheres at the surface of the formulation. what I am facing is that metal coated glass spheres are sinking in resin system so it could not get the light reflection that I want. Is there any ways that - plausible in solid compositions-
that I can use to bring glass spheres on top ?
I was thinking to create surface tension difference which might lead to phase separation but since there is NO solvent\water , I could not accomplish.
it is a nanocoatings so we can not flip any sides.@MohammadRezaZamaniKouhpanji
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Can any one suggest a stable electronic circuit which can measure very low phase angle, of the order of minutes between two sinusoidal voltages at power frequency.
It is possible to measure the phase shift angle between two voltages with the help of comparators for calibrating instrument transformers. Phase displacement of 10 angular minutes can be measured with the standard uncertainty at the level of about 0.06 angular minutes.
The task of determining the phase shift angle between the two AC voltages can be solved using a precision multimeter measuring three voltages: each of the shifted voltages V1 and V2 and the difference between them V3.
Then calculate the phase shift by equation: acos {V1 / (2 * V2) + V2 / (2 * V1) - (V3 * V3) / (2 * V1 * V2)}.
So, you can define 0.07 angular minute with uncertainty of 0.003 angular minute (see "The method of measuring the phase shift angle between two voltages using a precision voltmeter").
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I am going to create phase-randomized surrogated time series [they can be generated by randomizing the phases of the Fourier transformed components of the original time series between 0-2pi] for my daily or monthly time series, but to keep the cycle of fluctuations in the generated times series I want to keep the original phase related to the most significant frequency of my original time series in the generated ones.
I found the most significant frequency of my original time series which is 0.002738601 and so is related to the period (T) of 365.1499 days which means it is related to the Annual Cycle.
Now I want to keep the original phase related to this frequency in my generated time series, while all other phases are randomized between 0-2pi.
I can make my phase-randomized generated time series but I am not sure how can I keep the phase related to a especial frequency in the generated time series.
I changed the format of my question by removing my codes and explaining it more clear.
I am doing my coding in R, but this question can be assumed as a general question related to signal analysis.
Here is how I would do it in Matlab:
Generate a signal that consists of two sinusoids of frequencies 15 Hz and 40 Hz. The signal is sampled at 100 Hz for one second.
fs = 100; t = 0:1/fs:1-1/fs; x = sin(2*pi*15*t) + sin(2*pi*40*t);
Compute the discrete Fourier transform of the signal. Plot the magnitude of the transform as a function of frequency.
y = fft(x); ly = length(y); f = (-ly/2:ly/2-1)/ly*fs;
Compute the phase:
phs = angle(fftshift(y));
Compute the phase of the peak amplitude fft:
[~,maxindex]=max(abs(y));
maxphase=phs(maxindex);
Generate random phases:
phasemin = 0; phasemax = 2*pi; fftlength=length(y);
newphase = (b-a).*rand(fftlength,1) + a;
Inject the previous phase of the maximum peak in fft:
newphase(maxindex)=maxphase;
Note that this is for a double sided spectrum. The code needs some adapting, seeing as it is done for a double sided spectrum, but the approach is similar. Hope this helps.
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Hi all,
I'm performing a total nucleic acid extraction from viruses as follows:
- lysis of capsids by EDTA+SDS buffer with proteinase K, incubation 1 h at 55C.
- addition of protein precipitation reagent (likely ammonium acetate).
- spin 10 min at 10,000xg and then transfer supernatant to a new tube.
- add 1 vol of cold isopropanol. Mix by invertion (30x).
- Spin 30 min at 20,000xg....
My problem is that after this last centrifugation, a bottom bubble of aqueous phase is formed in determined tubes.
Curiously, the bottom bubble is only formed in those samples in which initially the virus in 1 M sodium citrate buffer. Samples for which the virus was in ascorbate-Na2EDTA buffer didn't show bottom bubble after centrifugation with isopropanol.
What's the problem here?
thanks!
Hi Utsa,
the problem is solved now! I did a small experiment testing a range of different citrate concentrations. Only the one I was using (1M) gave again this aqueous phase bubble, but I had normal precipitation with 0.5, 0.1 and 0.01 M citrate.
thanks!!
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Hello:
I´m working on an analog active crossver in the audio range and need to achieve zero phase (or close to it) in the pass band. I have tried several prototypes but now I discover several differences between the real components (opamps) and the simulations (i tried a 5532 from internet and the 741 from Texas and both showed differences, one in amplitude and the other in phase).
I´m a bit stuck and don´t know how to face this challenge. I already asked in facebook groups, linekdin and here at university, but I´m not clear about how to fix simulation issues and how to organize the design process. This is my first electronics design job, so any help will be appreciated.
In the beginning let us confine our study on the simplest op amp circuit, which is an inverting op amp amplifier with resistive feed back.The phase shift of such amplifiers has single pole with a phase shift of -45 degrees at the - 3dB point. So in order to limit the phase shift you have to operate your amplifier in the region of the flat frequency response.
The gain can be expressed by A= A0/ (1+ jw/wc),
Where Ao is the gain at zero frequency, w is the frequency of the applied signal and wc is the cut off frequency. The phase of the gain A, phi= - tan^-1 w/wc, for w/wc=1, phi will be -45, phase lag by 45 degrees.
If we want to limit the phase delay of the amplifier to a specific value say phil: phi limit, then as phil is very small, one can approximate the phse relation ship as:
phil= - wl/wc,
Then one can gat wl= phil x wc, and fl= phil fc
fl will be the maximum input frequency, phil is the allowed phas delay, and fc is the required cut off frequency of the amplifier.  If phil= 5 degrees= .0 8726 rad, fl= 10 kHz,
Then fc= 114.6 kHz.
This example shows how far cut off frequency is much greater than the audio signal frequency.
The question now what is the required gain of the amplifier A0 of the amplifier,
Say A0=10,
Then the minimum required gain bandwidth product of the op amp FT= greater than 114.6x10= 1146 kHz= 1.1 Mhz.So, the op amp 741 can just provide the required function with upper bound given above, that the gain of the amplifier must not be greater than 10.
Till now it is okay? not just so, because the amplifier has this bandwidth for small signals in the millivolt range. As at large signal the op amp speed is limited by its slow rate.  Since your signal is large then you have to use op amps with very high slew rate dV/dt,
For a sinusoidal wave with  max dV/dt= Vsm wl= 1Vx 2 pi 114.6 k=720 k V/s, So you an amplifier with a slew rate not less than 1 V/us if your amplitude is limited to 1V.  If you want to amplify signals with higher amplitude you have to scale your slew rate.
Please you can build your circuit on the light of my analysis in this post. You problem will be solved.
Best wishes
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I am observing the shift in peaks in a mixed phase system (2 phases). I observed the peak shifting is more at higher angles i.e if it is 0.2 upto 2 theta =30 degrees which increases to 0.4 towards higher 2 theta  value. What is the possible reason for this? In addition I would like to ask is it possible to have peaks corresponding to  high 2 theta value without seeing significant intense peaks (by any means) .
• Beware of fluorescence from Fe with Cu target.
• Index the XRD pattern to the best of your ability.
• Use Rietveld analysis.
• Post data in Excel format.
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i try for finding by using the formula given in attach file but in vain. The reported value for a, b and c is same that i find for 'd'(inter planner spacing) in each case.i want to find a, b, c values by using 'd' in given formula.
Any body can help me....?
thanks all of you for my correction.
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I am constructing a dynamic model (using ordinary differential equations) of Three Phase Fully Controlled Unidirectional Rectifier. And I am facing problems regarding the triggering logic of Thyristors. I would like to know if anyone can give any suggestions regarding various methods available for the triggering logic of thyristors (especially for the dynamic model). Any help would be greatly appreciated.
You could trigger them with the pulse generator. It's important you trigger the correct sequence of the thyristors. For example if you have a three phase system with 0, -120 and -240 degrees you have to trigger in this sequence to obtain the same behavior as diode bridges (first the top left one, second the right bottom, then the top middle, then the left bottom, then the top right and last the bottom middle). The times you trigger them you should calculate based on the times the sine waves of two phases match in one point. If you accomplish this, you can add different delays to the whole bridge to control the DC link
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I couldn't get a satisfactory yield of 1-hexadecyl imidazole using the attached method. Can anyone suggest me a better way to get a higher yield?
Crystal Growth & Design, 9(10), 4429-4437; 2009
Or this one:
Ind. Eng. Chem. Res., 2012, 51 (19), pp 6641–6647
Use an excess (~1.2 eq) of the alkyl bromide since it can easily be removed from the reaction mixture. You want to make sure you convert all of the imidizole.
Also, use very dry starting materials and solvent to avoid making the alcohol from the bromide.
Email me if you want to discuss further:
Good luck,
Chris
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In addition, if two microwave have the same phase, does it mean they are coherent? Thanks
Two microwaves with different frequencies have the same phase at regular intervals, the interval is 1/(the difference between the frequencies).  It is nearly like asking "If two trains with different window spacing are travelling beside each other, are the windows opposite each other?"  The answer is sometimes, in some places, but never all at once.
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I have toluene  solution of a monomer. If i heat the toluene above it's boiling point in an auto-clave,  will there be some monomers molecules too in the vapor phase? Actually I need these monomer molecules in vapor phase for surface reaction on a solid (covered with the other monomer). Thanks
Thanks Dear Larry. That was quite helpful
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In case that the p and q are predefined, which the most complicated phase in RSA algorithm. Is it the computation of "m^e mod n" ?
Hey Laouid. RSA algorithm chooses two random distinct prime numbers p and q. p and q are secret data. n = p x q is public data. Most complicated task is to achieve p and q from n.
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magnitude and phase calculation for multi-degree of freedom system using frequency domain method??
Thank you sir for your help..
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Acinetobacter baumannii: An Emerging hospital based pathogen,whose morphology seems to be  Coccobacilli, however, It gives few rod and spherical morphology also in my ESEM images. apparently, this is not contamination for sure. I repeated this thrice but getting same morphology all over again.
Moreover, some literature suggest that during the log phase, baumannii appears as rod shapes but during stationary phase its turns to coccobacillus.
Does anybody have any Idea? regarding its morphology, I would be grateful! to receive comment over it.
Gram variable coccobacilli
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What phases are shown by the attached XRD data peaks?
Phase Analysis Report
ndex Amount (%) Name Formula sum
A 82.3 Calcium sulfate Anhydrite Ca O4 S
B 6.9 Zincite O Zn
C 5.9 Oldhamite Ca S
D 2.6 Ca (C O3) C Ca O3
E 2.0 Calcite C Ca O3
F 0.3 Lime Ca O
24.8 Unidentified peak area
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I am working on a plant fraction and its weight is 24 mg.. I tried it on TLC normal phase using CHCl3 methanol system 10;1 and reversed phase using methanol; water 8;2 but there is tailing which makes it difficult to run on HPLC .. so what is the solution
@Sherif...
Please look at my reply and give some answers. Unless you are running normal phase  on both HPLC and TLC, or reverse phase on both TLC and HPLC, you can't see which solvent system is best. The selectivities of the two systems are different, and a method in one (normal phase or reverse phase) won't transfer to the other.
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Does light change phase when reflecting off a metal surface?
thank you very much Rituraj Verma
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It seems to be an amorphous phase but I could not identify it !
Dear Ghassen,
I thinks that you haven't amorphous phase in your sample. But you have clay fraction. you can verify this by oriented blade technique.
Best regards
Mohamed
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From the literature, I know that ZrO2 have different structures at different temperatures i.e. monoclinic (m) at room temperature (RT), tetragonal (t) at 1478 K and cubic (c) at 2650 K. I want to calculate the energy of all the three phases (m, t, c) at above mentioned temperatures i.e. at RT, 1478 K and 2650 K. My expectation is that (m) phase should have the lowest energy at RT among the three, (t) phase should have the lowest energy at 1478K among the three and (c) phase should have the lowest energy at 2650 K among the three. How should I go on with such simulations in LAMMPS? Which thermostat to use and how to define temperatures that I wish?
Please see Song and Hoyt, Acta Mater. 60 (2012) 4328-4335.
In order to find out the most stable phase, you need to find out the Gibbs energy (or practically, the Gibbs energy difference with respect to some reference phase). You can see in the above cited paper that they have used NPT (zero external pressure) ensemble with liquid as the reference phase. (The problem with NVT could be that you would be sampling the systems at different pressures and they could be under stress, at times, unless the right volume is used). But as commented by Tao Wang, it is less likely that one potential can cover all the phases in question. If if does, the transitions temperatures (obtained from the potential) may most likely be different from what you expect. So, it is better to get the free energy differences as a function of temperature with crossed fingers. Again, in the above referenced paper on Fe, you would find that the potential is not able to show the bcc-fcc-bcc transitions. So the results shouldn't be treated as surprising.
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Al12Mg17
cif file
crystallographic information
COD
Thank you so much.
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What analyte could not be separatet by Reversed Phase Chromatography? Ionic ones? May there are some Others?
I note some replies about solubility in polar solvents above- please consider "non-aqueous reverse phase"  as described here:
Snyder, L.R.; Kirkland, J.J.; Glajch, J.L.; Practical HPLC Method Development, 2nd Ed,
John Wiley & Sons, 1997, p.264
and demonstrated here:
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Dear Colleagues
Greetings
I would like to ask about the CuS and Cu2S pahses, why CuS is more conductive and less transparent than Cu2S phase?
Thank you
Fayroz
Dear Prof. Gerhard Martens
Thanks a lot for your interest and response.
Best regards
Fayroz
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Provide me some simple and easy to learn, that how to calculate the complete efficiency during photosynthesis, in both macro and micro phase.
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I've tried selfing on the same umbel by brushing with Kimwipes, but it doesn't seem to have worked. Maybe crossing from male-phase umbel onto a female-phase umbel? I'm not sure if the phases overlap enough. Anyone have thoughts?
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Hi everyone. Please clarify me the basic question related to filters.
As we know that the ideal magnitude response of low pass filter is shown in Fig below. It signifies that, it passes low frequencies and attenuates high frequencies. Similarly, please clarify me what is the significance of ideal phase response of low pass filter (order may be two or three) with Figure (ideal phase response of low pass filter)? Thank you.
The ideal phase response for the filter whose magnitude response is provided in the question will be almost same as the figure provided with a pass-band phase of 0o and stop-band phase of -90o.
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How can I use Phase modulator to apply quadratic phase on previously generated pulses from intensity modulator?
Dear Andrew Metcalf, Thank you for the detailed answer.You answered precisely what I wanted to understand.Now things are much clear.
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I’m facing some challenges in calculating Standard Means Difference. Student A obtained zeros in all baseline sessions. I subtracted the mean of the baseline phase (M = 0) from the mean of the intervention phase (M= 13.41) and then divided by standard deviation of baseline (SD = 0). The results will be error.
Any thoughts?
The correct formula for Standard mean difference is here: https://en.wikipedia.org/wiki/Strictly_standardized_mean_difference
If standard deviation of the intervention phase is not 0, the result will be fine.
Best wishes.
Ziyi Chen (Peter Green)
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three phase unbalance power flow using backward-forward method
Dear Sir,
I am facing problem in writing matlab code for three phase load flow analysis using backward-forward sweep method. Can u please provide me matlab code (conventional/general method will also be enough)?
Cheers,
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I am interested to know about the Golay plots in Gas Chromatography.
Dr. Wahab:
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Hello Dr. Gavril
I am taking a theory on chromatography class. I came across a question in which our professor wants us to do some research. I am wondering if you can steer me in the right direction. The question is:
The mass transfer in the stationary phase in negligible compared to the mass transfer in the gas phase. Show that this assertion is true?
In the case of G-L interaction, you can check ps 23-24, in the following material, dealing with two-film theory in the interfacial area: http://mimoza.marmara.edu.tr/~zehra.can/ENVE401/10.%20Two%20Film%20Theory.pdf
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I am trying to calculate the interfacial energy between two crystalline phases. Any guidance in this matter will be very helpful.
The most useful tool for developing interface is ASE-GUI (https://wiki.fysik.dtu.dk/ase/ase/gui/gui.html). You need to have basic understanding about python. I highly recommend this tool for developing crystal structures.
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I am simulating the effect of an grid voltage amplitude imbalance on a PLL structure. However, I want to know if an amplitude imbalance (e.g. a sag in phase A), must be accompanied by a phase imbalance as well. Is it a realistic to simulate amplitude imbalance while the phase remains the same?
Phase to ground is most likely to start failing on long transmission lines. Wet weather, old insulation, interference from animals mostly birds squirrels and snakes. ice accumulation, lost kites, defective crop dusting, unauthorized access, and any number of other causes can lead to amplitude imbalance.
Sometimes imbalance is deliberate and sanctioned by the power company. Example when a small to moderate size single phase user is fed from one phase of a three phase system. This is a phase to phase imbalance usually of small extent, but requiring management.
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How to find out the hkl values and phase corresponding to the smaller d spacing (below 1,eg.0.279) obtained from SAED pattern analysis?
Thank you sir..
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Using reductive perturbation technique we have derived the KdV equation and there we are getting the phase velocity 'u' as a complex number under some conditions. In that case, what can we conclude?
If there is a real part there will be propagation.  If there is no real part the wave is evanescent, it only stores energy each half-cycle.  The imaginary part describes reduction in strength with distance, usually called attenuation.  Damping usually refers to reduction in size with time (omega having an imaginary part).
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Options a) -40Hz b) 0Hz c) -22Hz d)20Hz e)None of the above
Why none of the above sir?
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I have heard we can use the phase and amplitude modulation of SLM to implement a lens on SLM. How should I do it, please provide some references. Thanks
Dear Sahil,
in addition to the previous mentioned paper and lecture, you can add the following material:
-Akondi Vyas et al., "Spatial Light Modulator for wavefront correction", 2009.
-A Reflectance Display: Supplemental Appendix - Harvard University at vision.seas.harvard.edu/reflectance_display/SLM_appendix.pdf
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I have some diffraction patterns and i am attaching.
Except one pattern i dont know what phase is it. Either Al20Cu2Mn3 or Cu3Mn2Al...
please let me know how to do analysis and suggest some literatrue...
Hi man, Please see the papers and books below,
A Handbook of Lattice Spacings and Structures of Metals and Alloys, By W. B. Pearson.
Advances in X-Ray Analysis: Volume 9 Proceedings of the Fourteenth Annual, By Gavin R. Mallett, Marie Fay, William M. Mueller
Hope this help.
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If anatase, rutile and Brookite phases are present, how would you calculate the percentage? Is there any software available like Rietveld Analysis?
you can choose any user friendly softwares such as POWDER CELL , GSAS,  MATCH, etc., which will give the quantify ratio either in manual or automatic mode. you just compare the stimulated pattern with the observed pattern then u can proceed accordlngly...
all the best
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I need .cif file for Ca-Sialon which i couldn't find on online database. It would be great if someone could provide me the .cif file.
Regards
Bilal
Hi Bilal,
There are several examples in the ICSD-Database of it - e. g. the collection code 20-1683 for a Ca-alpha-Sialone or the isostructural Eu-alpha-Sialone 16-7908.
If you can't find any of these, you can also use alpha-Si3N4 as the basic structure (alpha is the one with space group P31c). You will have to adjust the lattice parameters by a bit. Ca will enter the structure on the 2b-site with a z of around 0.24 depending on the exact composition.
Hope this helps.
Regards,
Daniel
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Hello,everyone.
1,can I  extarct spiramycin from fermentation broth using PEG4000/PEG6000-Na2SO4/(NH4)2SO4 system?
2, if the  aqueous two-phase system is formed, how can I know which is the PEG-riched phase or aqueous-riched phase?
PEG 4000 density 1.09 g/cm3 Density of solution Na2SO4 25 0C, 29%, 1. 3 g/cm3
PEG solution is at the top. Inorganic salts solution is in buttom.
Best regards.
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I'm working conversion of glycerol  to value added value added product in gas phase. i want to convert liquid phase to gas phase. if any external vaporized processes? how? or any system? or general idea liquid to gas?
If you want to convert liquid glycerol into gaseous glycerol you have 3 options: increase temperature, decrease pressure, and both simultaneously.
If you are trying to produce gaseous non-glycerol products from glycerine, you will need to crack it chemically. I am not aware of any efficient gassification reactions with glycerol other than combustion, but it could be an interesting research direction...
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Hello,
I am working on a piping network consisting of one inlet and two outlets. I am introducing air(primary phase) and water (secondary phase) into this network and I am interested in finding out the mass flow rate of each phase through each outlet. For this purpose I am using Eulerian multiphase model in Ansys Fluent. The problem I am facing is, the mass of each phase coming out of the two outlets is actually greater then the mass introduced at the inlet.
Can anyone help me with this ? Thanks
Hello Ahmed,
Do you use the fully-resolved Euer-Euler model (mass and momentum equations for each of the phases) or the Euler mixture model in ANSYS Fluent? Assuming the first, you may want to check your solver settings, in particular the descretization schemes - second order schemes may be preferrable for the mass conservation, even though they show less convergence. In previous works, I got good results with the QUICK scheme for the volume fraction and momentum, even though the First-Order-Upwind is set by default. Which convergence criteria did you define (usually the absolute criteria for the residuals is set to 0.001)? This may be not sufficient to meet mass conservation in your system. Also, do you achieve these criteria at all? If not, you may want to modify the relaxation factors - in my own cases the default settings were tyically too high (I often reduced the factors for density, body forces, momentum and turbulence by a factor of 0.8 compared to the default - this usually increases the number of iterations but can improve the convergence).
Last but not least (and I should have asked this first): do you use a transient or steady-state calculation? I haven't seen ANY steady-state multiphase case that gave correct results and mass conservation in a multi-phase simulation. Of course, then the defined time step size can also have an influence on your results - just make sure that the time step size is small enough, but ensure that the simulation doesn't run forever...
Hope this helps.
Regards,
Stephan
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Has any one used a voltage controlled phase shifter in the measurements of phased arrays? i need some help in clearing some ambiguities regarding the use of voltage controlled phase shifters in phased array radiation pattern measurements. Your response will be highly appreciated.
Semiconductor phase shifters, based primarily on GaAs, but also on SiGe and InP, have enjoyed steady progress for the past two decades. Their small size and relatively low power consumption  compared to ferrite devices has created new insertion opportunities. Many possible circuit topologies, using diode or FET switches in various configurations, exist.
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sampling rate is 100Hz
Give a try!
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The material is sinergle phase and present size lies in range of micrometer. I desire to increase up to mili meter range.
Thank u so much every one. The material included Chalcogen oxyhalgenide.
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In Phase measurement Unit (PMU), we require sampling clock pulses of 1pps through GPS. How will I create this Time synchronization or 1pps in MATLAB??
How will I generate timing pulses in order of 1 microsecond/1pps in MATLAB?
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I have 60 ml aqueous phase and 10 ml organic phase for nanoparticles while evaporating organic phase if I evaporate 40 ml of water too at rotary evaporator, is it right?
If you subject it for rotary flash evaporation, definitely, some amount of water will also get evaporated. The purpose for which you want to evaporate aqueous phase has not been mentioned.
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I can`t find the applicable software.
Hi Valerii,
Here is the segmentation recipe file and results I came up with. You may run this load this recipe in your copy of MIPAR and it will automatically segment and measure the area fraction of your particles. It came out to 15%. Let me know if you have questions!
Cheers,
John
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The small angle x- ray scattering profiles for ripple phase frequently indicate a 01 direction (as found in many literatures) but scattering along this direction is not found in the gel phase phosphatidylcholines, why?
The ripple phase is a 2D pattern with in and out-of-plane reflection in the SAXS regime. The gel phase is a 1D pattern in the SAXS regime. A nice paper showing this on aligned lipids is:
Katsaras, J, S Tristram-Nagle, Y Liu, R L Headrick, E Fontes, P C Mason, and J F Nagle. 2000. “Clarification of the Ripple Phase of Lecithin Bilayers Using Fully Hydrated, Aligned Samples.” Physical Review. E, Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics 61 (5 Pt B): 5668–77. doi:10.1103/PhysRevE.61.5668.
or
Rappolt, Michael, Heinz Amenitsch, Janez Strancar, Cilaine V Teixeira, Manfred Kriechbaum, Georg Pabst, Monika Majerowicz, and Peter Laggner. 2004. “Phospholipid Mesophases at Solid Interfaces: In-Situ X-Ray Diffraction and Spin-Label Studies.” Advances in Colloid and Interface Science 111 (1-2): 63–77. doi:10.1016/j.cis.2004.07.004.
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Mixture of metals that are not in single phase, but a mixture of two phases of individual metals themselves are also termed as alloys at many places. This creates confusion regarding definition of alloys. Could anyone please give clarity on this?
When two elements follow Hume-Rothery rules a single phase of the two elements in the solid state and the alloy is termed isomorphous alloy. This is the so-called ideal system. Departures from ideal systems occur in most cases either due to increased liquid clustering or solid clustering. The outcome could be eutectic, monotectic, peritectic and so on. In every case however, it is a (binary) alloy. See the text book by Schaffer, Saxena,et all for full details.
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three Phase Induction Motors
Its an AC three phase motor. whose applications are universal commonly seen as water pumping motors, and very popular motor, a lot of information is available over the net and in any Electrical Machines text books.. Few useful links are already posted above.
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For a 12 pulse diode rectifier is it necessary a transformer for a phase shift of 30 degrees. What is the difference between the Y/Y/D and D/Y/D transformers for 12-pulse rectifier?
The reason why Y/Y transformers are normally not used is that the neutral is not available at the primary side. Any zero sequence component experiences a high impedance.The reason is that the field pattern goes from yoke to yoke and this is a really much higher leakage impedance compared to concentric windings in normal field patterns.
One can avoid third harmonic and other zero sequence problems while using YZ configurations as well. It is rarely used, as windings from two legs are put in series and one has about 15% less voltage for the same resistance.
I used in previous times YY transformers for rectifiers with a low voltage output, with star point connected and 6 diodes to the +. It allows having 120° current blocks instead of 60°, without using a bridge. A third harmonic voltage appears on the neutral.
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I want to measure XRD on 1T-MoS2 phase, but sinceit is unstable phase I am wondering whether it will transform into stable 2H-MoS2 phase after measurement.
Although many phases are metastable phases, certain energy barriers will block their transformation unless the systems are stimulated by external forces, such as pressure, temperature and deformation. So far there is no report, to my best knowledge, that X-ray diffraction can stimulate such phase changes. X-ray may have photoelectric effects, and any such weak interaction with electron systems will not induce phase changes.
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I am doing the DICTRA simulation for AL12MG17_A12 phase.
But this phase is not available in any of the mobility databases. Can anyone suggest me where I can find the mobility data for this phase, or is it possible to proceed further without it?
It depends completely on the problem. If diffusion through the al12mg17_a12 phase is rate determining, then you shouldn't. If it isn't, or not to any large degree, then there are some options: assume that you can ignore the diffusion through the phase or find estimates of tracer/impurity diffusivities in the literature and use those.
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Trying to install Heterodyne Interferometry.
I am not sure I did understand the question. A lock-in amplifier should lock the reference frequency straightforwardly. The ref frequency can either be set internally or provided externally by a modulator that is also modulating the input signal. Phase locking is usually done by changing the phase until the amplified signal is minimum or even zero (that is searching the quadrature phase of the ref with respect to the input) and then adding 90° phase shift. Almost all lock-in amplifiers all have the Auto-phase option.
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Theoretically a signal peak  which appears within positive phase in DEPT135 should appear within negative phase  in DEPTQ. But mines, both  (meaning signals with same chemical shifts) appear in the same phase. Is there any reason why this happens? Is this normal?
My solvent peaks, however appear in the opposite phases. The pulse sequence for DEPTQ used is deptqgpsp.2
Sometimes, the software will take the absolute tallest peak (which could happen to be a negative peak) and flip to make it positive to make it easy to view.
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What kind of industry or process that use micro-extraction acetone from aqueous to toluene phase?  Please give an example of the application of it in that industry.
Useful!
1. High-speed gas chromatographic analysis of solvents in pharmaceuticals using solid phase microextraction
AR Raghani - Journal of pharmaceutical and biomedical analysis, 2002 - Elsevier
... we recommend you upgrade to a newer version of IE or use a different browser: Firefox ... in samples is one of the most demanding tasks for analytical chemists in pharmaceutical industry. ... On the other hand, correlation coefficient of acetone extracted from aqueous matrix with 100
A simple, inexpensive and rapid analytical approach for the determination of organic volatile impurities in pharmaceutical drug substances is developed, where sample preparation step was conducted using solid phase microextraction (SPME), followed by a fast GC separation. With an extraction time between 3 and 5 min and separation of 13 solvents in less than 3 min employing fast temperature programming using resistively heated column, organic volatile impurities can be analyzed within a total analysis time of 6–9 min. Various SPME phases were evaluated towards sensitivity and selectivity for the extraction of 13 commonly found solvents in drug substances dissolved in dimethyl sulfoxide and water. A 2-cm Carboxen/polydimethyl siloxane/divinylbenzene (Carboxen/PDMS/DVB) phase and a 65-μm DVB/PDMS phase showed better sensitivity towards these solvents when extracted from organic and aqueous matrix in comparison with the sensitivity obtained with direct injection approach. Extraction parameters such as extraction time, extraction stir rate, etc. are discussed. %RSD of peak area of replicate extraction was between 2 and 10% when 100 μm PDMS was used for extracting solvents from aqueous matrix. When DVB/PDMS fiber was evaluated for precision, %RSD of peak area from replicate extractions of solvents from organic matrix was between 2 and 8%. One-hundred micrometer PDMS showed excellent linearity from 10 to 500 μg/ml for analytes extracted from water solutions. On the other hand, DVB/PDMS phase showed better linearity than Carboxen/PDMS/DVB fiber when it was used to extract analytes in the concentration range of 10–5000 μg/ml from organic matrix.
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transport intensity equation
phase values
Phase shift(radian) = wavefront distortion(microns) x 2 pi / wavelength(microns)
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XRD analysis of Ceramic formed shows the presence of TiB2 and TiB phases, how will you distinguish both and how did TiB phases  formed along with TiB2
I would suggest using Electron backscatter diffraction (EBSD). SEM analysis could also help up to some extent since TiB2 and TiB have different crystal structures and morphology. I think attached three articles would be helpful. Best,
Azmi Mert.
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The 2 common winding types of three phase motors are star(Y) and Delta winding. In the catalog of a PMSM the Winding type is expressed as Wdg#1.
wdg#1 always star
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why in a traveling wave tube , in chart of phase velocity versus frequency, phase velocity decreases as frequency increases?
Simply phase velocity of the wave propagation speed in the environment. The phase velocity of the wave, wave it in the space of phase transitions. The speed of a wave frequencies can be defined for each phase. For each specific frequency can be quickly identified phase of a phase (eg wave peak) can be calculated. Phase velocity and wavelength can be obtained by wave period.
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Is the phase the same everywhere at the focal plane of a high NA objective? or the phase front is always spherical as it just pass the lens?
Yes,  the phase front is  the same(<RMS WFE budget) everywher at the focal plane of a hing NA objective.
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