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# Thermal Properties - Science topic

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I'm working on project where I need the thermal property of fertilizer but I have know Idea how to calculate it. Could anyone suggest the formula to calculate the thermal conductivity of solid mixture?
I need this thermal conductivity because the fertilizer I'm working on is getting heated during size reduction operation and I need to design Chiller to reduce heat from it. Hence, for Area calculations I need to calculate Overall heat transfer coefficient first and I can't calculate it without thermal conductivity.
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Using the Boltztrap and Quantum espresso I was able to calculate the electronic part of thermal conductivity but still struglling for the phononic part of thermal conductivity.
I tried the SHENGBTE but that demands a good computational facility and right now I am not having such type of workstation. Kindly suggest some other tool that can be useful for me in this regard.
Thanks,
Dr Abhinav Nag
There really isn't a comparable method in terms of computational cost at the same level of theory. The third order IFCs that you need to get the lattice conductivity require many force evaluations, so your best bet may be to reduce the level of theory at which you compute them. Of course this comes with its own drawbacks/concerns as well.
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In many cases, e.g. the thermal hydraulics of thermal waters, or the HDR or the one tube heat extraction, the estimation of the rock/water heat exchange is of central importance. It now turns out, that not infrequently the thermal properties of water and rock are so different that the the properties of the water can be neglected. This leads to a drastic simplification of the rock/water heat exchange. This is shown by an example, the heat loss of the thermal water in the discharge section.
It is strange that apparently no one has seen this so far.
The resistance is not a property of a substance, but primarily a property of the geometric configuration of this substance. And often the water layer is thin and therefore resistance is small. And Your discussion about the porosity tells me that I do not have to go into details about this in my text. Best thanks C.
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Can anyone provide ASTM E1007-90? For measuring concrete thermal property ASTM E1007 or ISO 10534-2-90 can be used?
Amit Shiuly Please check it in the attached files.
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We assume that the answer is yes and that it would be of great importance in the theory of heat conduction and in experimental measurements of the thermal properties of different materials.
There's the Sherwood number (Sh=Kd/D) and the Schmidt number (Sc=μ/ρD). There is a table in the CRC Chem Physics Handbook that lists every dimensionless number. The table includes the parameters (like thermophysical properties) so that you can see every dimensionless number that contains a certain property. You can use this to cross-reference the dimensionless parameters. Reynolds Analogy (St=f/2) and the Chilton-Colburn Analogy (f/2=Sh/Re/Sc^(1/3)) are very useful. For example, you won't find a correlation for the convective heat transfer coefficient (Nusselt number) for the entrance region to a tube sheet or through a pipe fitting, but you can find the pressure drop, which means you can calculate the friction factor, from which you can calculate the Stanton number, and ultimately calculate the Nusselt number. I have mass transfer examples that you can get free online.
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I'm researching on the comparative analysis of the different waste-based innovations in the Philippines but the existing materials do not have information on its thermal properties. Is there any testing center in the Philippines that specializes in testing for thermal properties or maybe thermal comfort?
Sorry, I don't know any testing lab in the Philipines, but the attached hadndbook may helpo you or any lab to do the job.
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The study revolves around finding the mechanical as well as thermal properties of a bamboo species commonly found in North Eastern states of India. For example, on the preliminary studies conducted, there have been no such properties found for thermal coefficient of expansion, as well as the properties of the particular species to conduct analysis for FEM analysis on a Bamboo Cross-Section.
It would be of great help if someone could help me find these properties for my final year thesis.
Wishing a huge thanks to everyone in advance.
See attached book chapter
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Hi there,
I'm working for graduation thesis, and want to simulate the heat generation process of 18650 battery, and i need to have some parameters from experiment like Resistance vs SOC, entropy change vs SOC, ... I searched the data sheet from manufacturer, but it's not enough.
Any body know about it? Please give me. Thank you so muchhh.
Dear Tan,
I would like you to suggest some important papers.
for basic understanding.
Friedrich Emanuel Hust has already shared some data related to it.
Regards,
Ekta
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I have performed some thermal transport calculation of multi-component alloys using MD simulation. Now, I am trying to see the effect of chemical short-range order on these thermal properties. I have read some related papers, but they are not describing this method elaborately. If anybody can provide me some directions regarding this short-range order in MD simulations, it would be a great help.
I have the same question and am waiting for the answers.
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I am studying and researching on a nano sheet using quantum espresso computing software. But how to do PDOS, phonon,thermal properties calculations I do not know, with this software and I do not have anyone to teach me, please help me if you have information including: booklet, PDF, command ....thank you
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I have a pipe that carries a fluid. The pipe is drawing heat from a source and is transferring to the fluid which is being circulated. I need to know the exit temperature of the fluid.
Known variables are:
1. Inlet temperature of the fluid
2. Inlet pressure of the fluid
3. Outlet pressure of the fluid
4. Constant mass flow rate
5. Thermal properties of the pipe
6. Temperature of the pipe
Goal:
Exit temperature of the fluid
How to proceed with this question?
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Machine learning, for example Artificial Neuron Network method has benn widely used in predicting various properties of oxide glasses in recent years, including mechanical, chemical and thermal properties, etc. but it is rarely used for non-oxide glasses (e.g., fluoride, fluorophosphate, chalcogenide).
What is the reason, because few data can be obtained for non-oxide glasses as compared with the oxide ones?
Hi, Mohamed, main parameters of various optical glasses can be obtained from the database of glass manufactures such as Schott, Corning, Hoya, Ohara, CDGM, etc., just for specific applications.
More conveniently, you can get massive amounts of data from both the Interglad and SciGlass databases, for which you can refer to the paper-Glass Property Databases: Their History, Present State, and Prospects for Further Development.
Cheers
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Anyone has experienced using the AFLOW framework to predict the mechanical and thermal properties of high entropy alloys?
For Mechanical Properties Calculating, There are not Different Between High entropy Alloys and Other Alloys and Metals.Furthermore, Researches Indicates that some High entropy Alloys have Considerably Better Strength-to-Weight Ratios, with a Higher Degree of Fracture Resistance, Tensile Strength, as well as Corrosion and Oxidation Resistance than Conventional Alloys.
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I am looking for the viscosity of paraffin waxes like C18 ,C22 and etc. I have been searching for the viscosity or temperature dependent viscosity of different paraffin waxes for a week and yet can not find it. Is there any reference that you can suggest, which include thermal properties of paraffin waxes such as C18, C22, OM47 and etc.?
Dear Nazanin Variji, please check the following website. My Regards
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I need to know the best proportions of graphene oxide to add in the cement mixture and does it affect the thermal properties?
Hi Dr Zainab Basim Abd . I hope the following article could help you: https://www.hindawi.com/journals/tswj/2014/276323/
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I am using indocyanine green in my simulation research project. from google and disparate papers i got some optical property of ICG nevertheless i didn't found any thermal property! it would be so much obliging if someone render thermal and optical property of ICG for different wavelength of light !
Dear Torikul Islam this is a very interesting question. In addition to the valuable references suggested by Manuel Gómez and Hayder Ibrahim Mohammed please also have a look at the following potentially useful articles:
Optical properties of indocyanine green under ultrasound treatment
The paper is freely available as public full text.
This is the RG link to the paper suggested by Hayder Ibrahim Mohammed:
There is also a freely accessible PhD thesis on the following topic:
(see attached pdf file)
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I am using Gaussian 16 software.
Check these out including 2021 article:
ACS Appl. Nano Mater. 2021, 4, 5, 4474–4483.
Chapter 6: Thermal Properties of Crystals | Engineering360 (globalspec.com).
(2002) Thermal Properties of Crystals. In: Fundamentals of Solid State Engineering. Springer, Boston, MA. https://doi.org/10.1007/0-306-47567-7_7.
Thesis | Thermal properties of structure one hydrates using density functional theory | ID: 6d570200x | eScholarship@McGill.
Thank you
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Hi community
I'm working on a mono-layer compound I'm focused on electron phonon calculations and i want to calculate thermal properties such us thermal conductivity and electron phonon factor G i want to know how i can proceed
best
Hello Serifi,
as far as I can imagine you ant to calculate more semi conductors because the phonons in metals are (more or less) unsignificant for thermal transport.
I would suggest to have a look at (theory) the book of J.M. Ziman: "Elektrons and Phonons", (application) D.M. Rewe: "Thermoelectrics Handbook" -- just for the fun of it I like to cite C. Herring "Transport Properties of a Many-Vally Semiconductor"BellSysTechJour, p.237(1955) -- "... And if the crystal is strained any or all of these parameters may change ..." :-)
Regards
Ernst
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I am trying to simulate solar cell using Lumerical DEVICE smulation software. I need to add material data for electrical and thermal properties. Where to find those?
I require data for PCBM, PEDOT:PSS.
Kindly help.
Dear Sandip Das ,
You can find the electrical and optical properties for the the intended materials in the following two papers:
and
Best wishes
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Dear all,
How to calculate thermal conductivities of composites using 3DFEA based RVE analysis, can anyone suggest the procedure? in Abaqus CAE
Best regards
Nagappa
The difficult part of RVE analysis is to apply the boundary conditions. The multiscale code SwiftComp eliminates all this difficulty by directly computing the thermal potential. It is pretty straight forward if you use SwiftComp. You only need to mesh the microstructure and providing the thermal conductivities for all the constituents.
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Hi I am working recently on a project where I have to study how the thermal properties or heat transfer enhancement of nanofluids as the volume fraction changes, or if a magnetic field is applied to a ferrofluid how does that affect the heat transfer. Is there a way I could model any of this in ANSYS. Im not sure but I was looking through ANSYS APDL to investigate this effects, is there a better way to model them.
as volume fraction increases heat transer increases due to the increase in the total surface of the nanparticles. hope helpful.
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I need thermophysical and electrical oil properties to investigation of DC discharge in oil.
Are multicomponent mixture models effective and precise in such calculations? If yes, what MC-modells can You suggest?
Thank you a lot in advance!
You may try several engineering models for a reasonable temperature range up to about 600 K to 700 K. Although there are no extensive data measurements for this fluid. The one-parameter friction theory model: https://doi.org/10.1016/S0378-3812(00)00474-X, combined with the Peng and Robinson EoS can give you some reasonable pvT, viscosity, and phase behavior estimations. This approach can also be extended to thermal conductivity.
But for most of the temperature range you are looking at, the octadecane will certainly be degraded. I even doubt you will have any CH4 left at all, as it starts decomposing at about 1000 K.
So, you need to first figure out what compounds you will have left.
But, at such temperatures, you are likely only to have some light gases and C. For the fluid phase, a simple model that may be useful to consider would be the one by Chung et al.:
I would start here.
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Especially the specific heat (Cp) at both liquid and solid phases. Thank you
Have you found any information Rami Ammar ?
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I want to study the thermal properties of the composite (MWCNT+silver nanoparticles), so what method of synthesis do i use so that the composite sustains itself under elevated temperatures.
It depends on the surface material. Electrodeposition is one the best option
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Hi all,
I am conducting physical experiments that involve heat exchange between the water being pumped inside a galvanized iron pipe and the pipe's surrounding heated temperature. I would later be simulating the physical experiments using a software (Fluent) as well and then comparing the numerical and experimental results. So, the thermal properties of the galvanized iron pipe I enter to the software should closely match the real properties of the pipe in order for the comparison to be successful.
I searched a lot of books but the thermal properties were either available for steel or galvanized steel. But I could not find any thermal properties for "galvanized iron" or even normal "cast/wrought iron". Hence, could anybody kindly suggest a resource where I may be able to find the thermal properties (thermal conductivity, specific heat capacity) of iron pipes - if possible "galvanized iron" specifically?
Thank you!
Sampath Suranjan Salins Thank you. Properties of Iron are not there in Ansys Fluent but will check the material databases in other Ansys software.
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I'm currently working on a project that involves the simulation of CHT (Conjugated Heat Transfer) problems potentially leading to the evaporation of a water/glycol mixture.
Thus I would need to have the thermal properties (especially the coefficient of volume expansion) of both ethylene glycol (1,2-ethanediol) and propylene glycol (1,2-propanediol) in liquid and gaseous phases.
So far I've managed to find (relatively easily) the properties of the liquid components, but nothing regarding the gaseous components.
Could someone points me in the right direction for such data ?
The ideal gas approximation can typically be used with reasonable accuracy for sufficiently high molar volume (or low pressure). Otherwise, the gases should be taken as real.
The real gas/vapour density of pure substances or mixtures can often be correlated quite accurately based on the corresponding-states principle. Accordingly the two-parameter principle of corresponding states; for real gases (or vapours), even if saturated, the same compressibility factor (Z) holds for both reduced temperature (Tr = T/Tc) and reduced pressure (Pr = P/Pc).
The compressibility factor can then be read from a generalized compressibility chart, obtained after published data (tables) from a well-known selected reference substance such as dry air or steam, calculated after some chosen equation of state, or estimated from some convenient PVT correlation.
For better accuracy, a three-parameter corresponding state approach is preferred. For saturated vapours, PVT data/predictions should be consistent with vapour pressure data/predictions.
The volumetric thermal expansion for the real gas can be then readily derived from PVT data/predictions, but also depends on the type of thermodynamic process by which temperature changes (e.g. isobaric, isochoric, polytropic).
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Greet
how can be defined S-CO2 thermal properties in EES?
it means that supercritical CO2 has changed thermal properties.
are the properties the same as CO2 in EES software?
thanks
There are 3 different types of system for CO2 working fluid. These are including sub-critical, trans-critical, and super-critical. Thermal properties of any 3 system calculated Similarly. These systems separate From each other Due to different working pressure.
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I am looking for a formula to calculate specific temperature drop in duct based on airflow, knowing the specific power loss, airflow, thermal properties of the duct, and air temperatures. The goal is to be able to produce the graph attached.
I can digitize the curves and obtain a formula that will accurately reproduce them if that would help. It doesn't tell why or reveal the basis but it's something, perhaps a step toward achieving the ultimate goal.
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Need to determine the thermal properties of a polymer.
Is DMA could provide reliable thermal properties: specific heat capacity, thermal conductivity, thermal diffusivity etc?
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I do not know how to determine if plasma treatment of lignocellulosic fibers provokes superficial crosslinking and increases hydrogen bonding between cellulose chains. I have only found unverified explanations and information to hypothesise. In this sense, does anyone know if experimental or modelling evaluation techniques are available?
Here, some related references:
Britannia Vondrasek and Omkar Singh Kushwaha thank you very much for your contributions.
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Dear all,
Can somebody please put some light on how the position of band inversion, near or away the Fermi level affects the electrical transport and thermal properties in semi-metals?
Thank you so much for the explanation and the picture, Dear Payal Wadhwa.
I will try to digest the adiabatic continuity hypothesis. Your explanation is very clear, thank you so much.
As I said previously, I am learning. These new materials are no sot intuitive as conventional ones. Your threads in RG are very informative and ask properly many questions regarding fundamental symmetries in solid-state physics.
An excellent review :)
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In order to model the crater formation (considering Inconel 825 as workpiece material) in EDM process, thermal properties such as Boiling temperature, Latent heat of melting and
Latent heat of vaporization are required. Where can I find the the values of the above mentioned properties.
Nice Dear Xiangzhi Wang
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Actually, I need free software for calculating thermal properties of crystalline solids namely, lattice thermal conductivity, and minimum thermal conductivity.
Your thread is a relevant one. ab initio calculation of thermal transport properties in different compounds, that is, semiconductors, normal metals, superconductors & other compounds.
Impurities effects calculations added to those nobel ab initio methods plays a fundamental role in their further development. Physical kinetics is a hard subject to study.
& the references given by this review:
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I am working in 2D materials, please suggest best open access software for windows to analysis of electronic, optical and thermal properties
Hi Bhanu,
I hope you are doing well.
I suggest "Quantum Espresso" which is one of the best DFT packages. It is user friendly and free. You can install it using this link:
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Hello to all :
This question is originated from the idea that every material (except for Superconductors) has a Seebeck Coefficient (S) different than zero, and from the idea that in every case when different metals or semiconductor materials are joined together, a Seebeck Effect at any scale is observed on the pair of materials.
So my question is:
When we measure the S of a given material, we place the sample between two plates at different temperatures, so we can stablish a Temperature Gradient and an unidirectional Heat Flux across the material. Then, we vary the Thermal Power imput, so we can vary the Temperature Gradient and obtain a set of Output Seebeck Voltages.
Then, we measure this Output Voltage and we plot a Graph of Delta(T) vs. Delta(V) as a linear x vs. y Graph. Finally we state that the slope of this Graph (positive for the N-Type materials and negative for P-Type) (because what we are measuring in our apparatus is the net Gradient (DeltaV/DeltaT), the formula in the Seebeck Coefficient has and additional (-) sign which turns S to a negative for N-Type semiconductors and positive por P-Type) is the Seebeck Coeff. for the material.
This measurement is always considered as if it was the absolute S coefficient of the material. But, What about the junction between the probe electrodes and our sample ? Since there is a Seebeck Voltage being generated at the junction too. Hence, our lecture from the voltmeter should be the Seebeck Coefficient of the junction: Se,s = Se - Ss
Where:
Se,s : is the Seebeck Coefficient of the junction between the sample and the electrode.
Se : is the Seebeck Coefficient of the Electrode.
Ss : is the Seebeck Coefficient of the Sample.
What do you think ?
Is this error virtually zero in practice, as much as we can ignore the effect of the Seebeck Effect of the junction electrodes/sample ?
How can we understand the fact that when we use these methods, we never talk about the contribution of he probe electrodes into the measured S Coefficient ?
Kind Regards !
Dear Thomas Anthony Troszak ,
if you use extensions of the same material and connect them under the same conditons, the additional thermovoltages rule out. But you must ever be sure, what you exactly do. Let me give an example used in practice:
Thermocouples are used in vacuum container to determine temperatures. Lets say, you want to bake out a recipient or you want to heat a sample holder to a certain temperature. You fix your thermocouple to the corresponding point the temperature T you want to control. It can be that the couple is not long enough. Furthermore, you have a feedthrough you must connect your wires with it. Then you have almost different metals. On the outside you must use a special plug which contains a contact of the identical material combination. The material combinations are standardized (example type K). The outer contact lies at room temperature. With a control unit which measures the T you control the heater. Of course, if you have more extensions, the contacts between different materials can be different (oxidation, lubrication). Therefore, it is important, if you want exact results, to control the measurement of T.
First test: The thermovoltage must be zero, if both contacts have the same T (room temperature). If there are any contact potentials then you see them.
Second test: You put your "hot contact" into a reference liquid (boiling point must be known). Then you must get the right temperature difference.
With Regards
R. Mitdank
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I am getting slightly different values of Tg from both DSC and DMA. The DMA results are giving me higher values of Tg compared to DSC. Which values should I trust?
Dear Tayyab Khan,
Two important applications of DMA are:
1. Measurement of the glass transition temperature of polymers
2. Polymer Composition
In the glass transition region, the storage modulus declines sharply and the loss modulus reaches to the maximum level.
DMA is more sensitive than DSC. The weight of the sample that is used for DMA analysis usually is more than that used for DSC analysis. Therefor, for obtaining thermal equilibrium, it is recommended to use low heating rates for example 2˚ C/min. In this way you can rely on the obtained results from DMA to measure the Tg.
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Dear colleagues, hope you 'r having a good day :
I may get somehow involved in a project about Sb2S3 for possible thermoelectric uses, behold the motivation behind my question.
I already searched for this in the literature, but the only I could find for was the electrical and thermal properties for Sb2S3 thin films. However I have bulk materials .
Does anyone have a good reference for the measured (or values) Electrical Conductivity, Seebeck Coefficient & Thermal Conductivity for bulk-Sb2S3, regardless of the fabrication method ? The material I have is a Sb2S3 compacted pellet.
Thank you for helping !
Regards ! :)
Franklin Uriel Parás Hernández:
You can refer this paper for the similar work related to antimony based material.
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Dear all :
May anyone share with me a Graph showing the curves for Temperature vs Thermal Conductivity, and Temperature vs. Electrical Conductivity/Seebeck Coefficient (in the same Graph) for distinct type of materials: (semiconductors, semiconductor alloys, metals, semimetals, etc.) showing the points in the range up to 1000°C ?
This is for use in Thermoelectric materials.
If someone can send it to me I'll appreciate it a lot
Thanks !
Dear Franklin,
You will get these graphs in many literature. But it is not possible to get these graphs upto 1000 degree celsius for all materials.
Anyway, I think it is better to get these results by your own Experiments because standard data always doesn't match with your working material due to impurities and difference in microstructures.
If anything you want regaring the Experimental details for these I can tell you ( but upto 600 degree Celsius)
Love and Regards
N Das
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Dear Members,
I am presently working on a project that mandates the modelling of temperature distribution across unclothed and clothed human skin tissue. The modelling should take into account the environment properties like temperature, humidity, wind velocity and biological parameters of the human body like blood perfusion rate, metabolic heat generation rate, thermal properties of various skin tissues etc..The geometry is similar to a co-axial cylinder assembly with each annulus representing a different tissue, such as , skin, muscle, bone, and blood. Kindly suggest a stepwise procedure for solving the problem using ANSYS FLUENT. The geometry is attached herewith for your perusal. I am using Penne's Bioheat model. I have, however, not been able to include human tissue and its properties such as perfusion rate and metabolic heat generation rate in the material section. Kindly help.
Transient temperature arising from contact can be calculated analytically and does not require FLUENT or any other "model". If you do use a computer model, then you will determine the outcome from the inputs provided. In other words, you can get any answer you want, depending on what you put in. If you indirectly specify the answer up front, you will not learn anything new about the process. I suggest that, instead of calculating it, you measure it. I designed a thermocouple capable of measuring heat transfer at rates in excess of 12,000 degrees C/second and presented the results at the 1982 International Heat Transfer Conference in Munich. The guy who fabricated the thermocouple for me (Doyle Dukes, who is long deceased) made replacement parts for antique watches and clocks. You may have a little trouble finding a watch maker, and it may cost more than the \$20 that Doyle charged me, but it can be done!
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I am trying to calculate the interaction of a laser with refractory borides such as ReB2 and require this data.
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I am trying to model a composite made of both unidirectional and bidirectional prepregs. Is there a standard way to go about it? Furthermore how can one evaluate the thermal properties of a laminate made of BD prepregs?
Check following articles
On the constitutive modelling and damage behaviour of plain woven textile composite, International journal of solids and structures, 156-157, 73-86
Multi-scale approach based constitutive modelling of plain woven textile composites, Mechanics of materials, 112, 172-192.
Multi-scale damage framework for textile composites: application to plain woven composite, European Journal of Mechanics / A Solids, (DOI:https://doi.org/10.1016/j.euromechsol.2019.103809).
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I am a current MS Physics student where I work in a research lab studying condensed matter. Specifically, I use DFT based models (VASP, Quant. Espresso, Wien2k) and other software (ShengBTE, phonopy, thirdorder.py) to make calculations of electrical, magnetic, and thermal properties of materials.
I am curious to know how skills and experience with these programs translate in the professional world and career opportunities. I was unsure whether to post this as a question but I figured a discussion was more appropriate. I hope to get some insight from users of this site that can provide input on this topic. All responses are appreciated and encouraged.
Thank you.
Robert Appleton
CSULA Physics
• A postdoc at a national lab (Army, Naval, Air Force, Sandia, Los Alamos, Brookhaven, Argonne, Livermore, Oak Ridge, Pacific Northwest, Nation Renewable Energy research labs, etc.)
• Technical staff at a supercomputing center (NERSC, DOD HPCMP, XSEDE, etc.)
• Program manager at a funding agency (DOE, DOD, NSF, etc.)
• Industry research at a Gas company (ExxonMobil, Air Liquide, Air Products, etc.), pharmaceutical company (Johnson & Johnson, Merck, Eli Lilly, Teva, Astra Zeneca, GSK, etc.), or chemical company (Dow, Dupont, etc.) - you can find a lot of postings here https://www.google.com/search?q=density+functional+theory&ibp=htl;jobs#fpstate=tldetail&htidocid=PoXCLwIlhOVbXnbdAAAAAA%3D%3D&htivrt=jobs
• Quantum chemistry software company, if you've done some programming (Schrodinger, Spartan, Gaussian, Materials Studio, QChem, VASP, etc.)
This is, for sure, not an exhaustive list. If you have any follow-up questions, I'd be happy to answer them.
Best,
Rob
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Thermal properties calculation using quasi harmonic debye model.
In ATK, the entropy is evaluated using the quasi-harmonic approximation (see Eq.(5.5) in Dove, Martin T. (1993), Introduction to lattice dynamics, Cambridge university press).
Refer
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I am looking for the thermal degradation pathway and products of 6-mercaptopurine (Temp.: 200-1000 Celsius, Inert atmosphere).
Any relevant reading suggestions are also much appreciated. Thanks.
Polyhydroxyalkanoates (PHAs) are bacterial polyeste ars used in the production of biodegradable plastics. PHAs accumulate in bacterial cells under nutrient-limited conditions in response to excess carbon . The thiopurine drugs, including azathioprine, 6-mercaptopurine (6-MP) and 6-thioguanine (6-TG), are purinergic antimetabolite agents with profound antiproliferative effects. Azathioprine is converted into 6-MP, whose enzymatically driven metabolites 6-thioguanine nucleotides and 6-methylmercaptopurine interfere with RNA, DNA and protein synthesis as well as promote apoptosis of proliferating T cells. Numerous mechanisms are involved in the antiproliferative effects of 6-MP, which include its incorporation into nucleic acids chains. In addition, recent evidence indicates that 6-MP inhibits the phosphatidylinositol 3 kinase (PI3K) / mammalian target of rapamycin (mTOR) signaling pathway, suggesting that these drugs might interfere with metabolic checkpoints and impact metabolic reprogramming in normal T cells and cancer. The possible role in cell metabolic reprogramming, 6-MP regulates the activity of members of the orphan nuclear receptor NR4A family, which acts as key transcriptional regulators of glucose and lipid metabolism.
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Dear Sirs:
I am working on a heat transfer model for hollow alumina spheres for high temperature aplications, but I have had a difficult time finding the thermal properties of alumina (Al2O3, 94-95% purity). In particular its thermal conductivity for a wide range of temperatures (300 K up to 2,000 K). It would be of great help if you could point me out to technical handbooks or specific research papers with empirical or even theoretical information for this property.
Best Regards.
Nicolás Ripoll
Nicolás,
Give the NASA Technical Report Server a try too - a wide variety of exotic materials will have been examined for aerospace use too.
(also free access)
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I am looking for an instrument(s) to measure thermophysical properties, specifically the latent heat of melting, thermal conductivity, and heat capacity of a PCM (phase change material).
Mennatalla Elmanzalawy you can use Differential Scanning Calorimetry (DSC) for latent heat of melting (technically termed as latent heat of fusion). Perkins have plenty of those on offer.
For thermal conductivity, you can use TPS method using Hotdisk equipments. A good company for that , to my knowledge, is Thermtest Inc.
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I need to characterize several metamaterials, specifically the thermal properties, I was wondering if there's a experimental technique focused in the measurement of the apparent thermal resistance of not heterogeneous materials with complex geometries such as the ones attached in this question.
Aaron,
As Leander suggested there are many standards.
I am familiar with ASTM's guarded double-sided hot plate method, reference C177.
We can directly measure the one dimensional thermal conductivity if you were to 3D print a few unit cells of those materials.
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QUESTION 1): According to the reference articles, hot disk method to low-density insulating materials is considered to be questionable, due to the low thermal conductivity and low thermal inertia of these materials when compared to the thermal properties of the probe.
Reference:
Coquard, R., Coment, E., Flasquin, G., & Baillis, D. (2013). Analysis of the hot-disk technique applied to low-density insulating materials. International Journal of Thermal Sciences, 65, 242-253.
when the method is applied to materials with thermal inertia strongly different from the probe (≈2 order of magnitude lower or more), the accuracy of the method becomes questionable. This is notably the case for common insulators used in the building industry like polymer foam or mineral wools. The preceding conclusions have been validated by experimental measurements on a standard low-density XPS foam sample and a superinsulating silica areogel. This is particularly the case for low-density XPS foams whose thermal inertia (r.C) is almost 2 order of magnitude lower than (rNi.CNi) and (rKa.CKa). In this case, the relative errors on k and (r.C) can exceed 10%. Lower errors are found for insulating materials with larger thermal inertia such as silica aerogel.
Answer from Dr. Silas E. Gustafsson - Pioneers of Thermal Conductivity Measurement ( silas.gustafsson@thermetrol.se ): Silas E. Gustafsson
Yes, it is true that the heat capacity of the probe is not included in the theory presented in my 1991 paper or in the standard ISO 22007-2 and so far, I have not seen any analytical theory which could take that aspect into consideration. The heat capacity of the probe is particularly important at the beginning of the transient recording and it will cause a longer rise time of the current and somewhat delay the output of power into the substrate. The traditionally way of taking this into consideration is to apply a time correction, which I think is a facility included in the commercial software.
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I have a few factors like temperature, humidity, radiation and thermal characteristics that affect thermal comfort inside a building. Now, I need the thermal simulation for a model in Ansys.
Following.
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For my undergrad thesis, I need to know CTE (Coefficient of Thermal Expansion), Poisson ratio, yield stress, Young's modulus of AZ91 magnesium alloy .
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I'm working on a research where we use laser induced forward transfer to place a nanowire on an interdigitated micro-electrode. The nanowire is originally suspended on ethylene glycol and part of the EG evaporates as part of the process. To make an accurate simulation of this process I need the thermal properties of ethylene glycol. Thanks!
Properties of ethylene glycol liquid at saturated state, k (thermal conductivity) and cP (specific heat)
at Oo C, k = 0.2419 W/m-K, cP = 2294 J/kg-K, density = 1131 kg/m3
20o C, 0.2489, 2382, 1116
40o C, 0.2559, 2474, 1101
60o C, 0.2594, 2562, 1087
80o C, 0.2617, 2650, 1077
100o C, 0.2628, 2742, 1058
The values above are takrn from Heat and Mass Transfer Data Book by C.P. Kothandaraman, S. Subramanyam, New Age International Publishers.
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Is there a technique by which one can characterize a structural and thermal properties of material at low pressure?
In order to study the thermal properties you can use PDSC – Pressure Differential Scanning Calorimeter. Is is differential scanning calorimeter under either high or low-pressure conditions.
Single crystal X-ray diffraction with specialized chambers, of high or low pressure, to study the structural properties.
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Hi,
Kindly suggest some articles where I can get mechanical and thermal properties of HDPE as a function of temperature.
Respected Rana Sir,
As stated in earlier comment by Raheem Al-Sabur sir, the applications of HDPE were not mentioned so I am uploading some generalized articles related to your need.
Hope it helps.
Regards
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In tribology of polymer cases we know that:
In contrast to other materials, the tribological properties of polymers depend on the tensile strength and the toughness rather than on the hardness. Due to their thermal properties, polymers are very sensitive to frictional heating. Please suggests in case of friction stir welding of polymer, property mainly depend on tensile strength or toughness or hardness?
Regards
Sudhir
Among three kinds of polymeric materials; thermoplastics, thermosets, and elastomers, only thermoplastics are the weldable polymers. It is due to their ability to be reshaped after heating below their degradation temperature.
Several researchers such as Bilici and Yukler are depending tensile strength especially lab shear.
Bilici MK, Yukler AI (2012) Effects of welding parameters on friction stir spot welding of high density polyethylene sheets. Mater Des 33:545–550
Regards
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We are adding RE elements in SnAgCu solder alloy to improve its thermal properties. Even through there isnt any large impact in decreasing of melting temperature then how to ananlyses the SAC alloy with these DSC graphs that its properties are improved. and what if graph contains more than one (or how closely or how large in amplitude) endothermic/exothermic peak.
It is difficult to analyze because the meaning of "305", "105", "0.15Ti", are not given. The thermograms indicate that "305" shows only one transition whereas other alloys show several thermal transitions with liquid+solid regions.
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I need the following values (literature references) for ITO :
1) Thermal conductivity
2) Thermal Expansion
3) Specific Heat
**Preferably as a thin film.
Yes. Please see the references we used for the ITO properties:
Absorption coefficient
1. N. M. Khusayfan and M. M. El-Nahass, “Study of Structure and Electro-Optical Characteristics of Indium Tin Oxide Thin Films,” Advances in Condensed Matter Physics, vol. 2013, Article ID 408182, 8 pages, 2013. https://doi.org/10.1155/2013/408182.
Poisson’s ratio, Young’s Modulus, Coefficient of thermal expansion
2. Nasr Saleh, M., & Lubineau, G. (2014). Understanding the mechanisms that change the conductivity of damaged ITO-coated polymeric films: A micro-mechanical investigation. Solar Energy Materials and Solar Cells,130(November), 199-207. doi:https://doi.org/10.1016/j.solmat.2014.07.011
Thermal conductivity
3. Ashida, T., Miyamura, A., Oka, N., Sato, Y., Yagi, T., Taketoshi, N., … Shigesato, Y. (2009). Thermal transport properties of polycrystalline tin-doped indium oxide films, 2–5. https://doi.org/10.1063/1.3093684
Heat capacity
4. Ohtaki, M., Ogura, D., Eguchi, K., & Arai, H. (1994). High-temperature Thermoelectric Properties, 4, 653–656.
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thermal properties of Silicon
That is clear, Thank you :)
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Flexural and shear strength values of common building materials?
Please check reference below.. hope it will be helpful for you… Regards…
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Actually i am performing some thermodynamic analysis for my system and i dopnot have the Novec649 refrigerant in my Refprop. I need the excel file in which Temperature (from -20 till critical point), Sg and Sf values are enlisted so that i can draw the Ts diagram for this refrigerant ..If somebody can help me with this...
Waiting...
In EES, the following equations are implemented:
Novec649 is a trade name.  However, it is used here for brevity to indicate fluid 1,1,1,2,2,4,5,5,5-Nonafluoro-4-(trifluoromethyl)-3-pentanone (CAS No. 756-13-8, Molar Mass=316.0444).
Property data for this fluid are provided using the Fundamental Equation of State presented in: Thermodynamic Properties of 1,1,1,2,2,4,5,5,5-Nonafluoro-4-(trifluoromethyl)-3-pentanone: Vapor Pressure, (p, ñ, T) Behavior, and Speed of Sound Measurements, and an Equation of State Mark O. McLinden, Richard A. Perkins, Eric W. Lemmon, and Tara J. Fortin J. Chem. Eng. Data 2015, 60, 3646-3659
The correlation is valid for temperatures in the range between 165 K and 500 K for pressures less than 50 MPa.  Enthalpy and entropy values are referenced to 200 kJ/kg and 1.0 kJ/kg-K, respectively, for saturated liquid at 0°C.
Viscosity is determined using the correlation published by: Chenyang Wen, Xianyang Meng, Marcia L. Huber, and Jiangtao Wu "Measurement and Correlation of the Viscosity of 1,1,1,2,2,4,5,5,5-Nonafluoro-4-(trifluoromethyl)-3-pentanone" J. Chem. Eng. Data 2017, 62, 3603-3609
Thermal conductivity for the liquid phase is provided using correlations based on data provided by 3M Corporation in: http://multimedia.3m.com/mws/media/569865O/3mtm-novectm-649-engineered-fluid.pdf
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Hello all :
I have just got myself interested on the topic of thermal transistors and started to search some readings about the subject, but it has n't come clear for me yet.
Does anyone can give a rough description of the working mechanisms of a thermal transistors ?
Is there a straightforward analogy between an Electric Transistors and a Thermal one ?
Are Thermal transistors and Heat transistors the same thing ?
Are there more than one kind of thermal transistor?
How can we associate the imput DeltaT or imput Heat Flux to the response of a Thermal Transistor.
I hope someone can give base ideas upon we can build a disscution on
Regards ! :)
Dear Franklin,
The basic functioning of thermal and electrical transistors is the same (a transport mechanism that has 2 differentiated states and a way to control that transport in a channel). In a normal transistor the on and off states are pretty much ideal (there are several orders of magnitude in the conductivity of the channel between states) and the control on the switch is almost ideal (ok, I am not talking here about charge trapping, capacitive couplings, etc). In a thermal transistors achieving something similar is rather difficult or
impossible. The heat flow (the equivalent to the current) is not characterised by a single carrier, but by a combination of electron transport, vibrations ( phonons in crystalline materials, propagons/diffusons/locons in amorphous), and finally radiation. The electronic contribution,if any, can be switched off using electromagnetic fields as in normal transistors. However switching off the other two contributions becomes really challenging. The diffusive part (vibrations) requires to somehow control how the atoms interact to each other in the material. A way to do that is by a controlled diffusion of a third material in to the lattice as in the above-mentioned paper. In a "dry" version you will need to look for something triggering a reversible phase change resulting in very different vibrational spectra for each state or something similar. As far as I know there is no easy way to do that, and the concepts proposed by Li in his seminal work have not been properly implemented yet.
Kind regards,
Julian
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Assume a design space of N physical variables (e.g. flow rate, particle size, thermal properties, etc.) that can be reduced to M < N dimensionless variables by applying dimensional analysis.
The region of the N-dimensional hyperspace which is experimentally accessible is assumed to be known. The set of dimensionless variables Qi defines M families of curves in sub-parts of the space, e.g. if Q1 = x1*y1 then y1 = Q1/x1 where x1, y1 are physical variables and Q1 a dimensionless variable that becomes as a parameter in this family of curves.
The question is now how to find "extreme conditions" (points) along the edges of the permissible physical (hyper)region that maximize the differences in values of the dimensionless variables?
For the simplest case of N = 2 and M = 1, this could be done graphically by taking intersections of the family of curves obtained by varying Q1 with the 2-dimensional region (e.g. rectangle) given by the physically accessible variable space.
For N = 3 this already seems more challenging and for N > 3 no direct visualisation seems possible.
Can anyone point me towards suitable algorithms or texts addressing this problem? The end goal is an experimental design in Q space yielding e.g. a regression function for a dimensionless target variable.
Dear Jan,
I am not sure if I understand your question... but typically I take "physical limits" for the variables to set the boundaries of the DoE and then to efficiently populate the space I use a flavor of the Latin Hyper-cube algorithm (see attached document).
Kind regards,
Julian
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During my work on mechanical and thermal properties of solids particularly for elementary and compound Semiconductors I found a Sharing point between solid-solid phase transition and the melting point of these materials. In fact any phase transition acts as a melting point temperature value in my calculations in equations to determine mechanical or thermal properties such as thermal expansion and crystalline structure of those solids. The phenomenon works also on nanoscale solids, please make use the following articles.
It is of my interest to open a discussion for further understanding in this regard
Dear Dr. Rietveld
Thank you for your comment and discussion on this subject. The idea In this case is when we deal with a case all the parameters should belong to the same situation one of them is the transition temperature, and similar parameters such as thermal expansion, lattice structure, Deby temperature .... in this case I ment inorganic materials . So any phase transition will change all the properties for the next phase.
According to this idea all the materials properties (parameters) should change with a transition temperature and that’s what I found at list the parameters lattice spacing, thermal expansion and phase transition for binary inorganic components
you are perfectly correct for the difference between the solid solid and melting transition but still the properties are belong the solid before it melts not during or after that’s why it should be all cases before it’s phase transition
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What I see is these are two of the severals ways to go about a hybrid composite, but I am curious about the difference which these processes would bring about in the composite hybrid just because of the difference in processes.
Process paramerters and manufacturing methods greatly influence the product properties of composites. Each process has its own merits and demerits. The concepts in composites are based on volume fraction and void fraction acheived after manufacturing. In fact you can tailor the product to meet your property requirements.
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We want to use calcium carbonate filled/reinforced homo polymer polypropylene for heat application - 290 Deg F for cycle duration of at least one hour or higher. Parts would be statically loaded and we would like no flat spot / heat deflection. Is there any other additive which may improve the thermal performance , if not by itself ( 40% Calcium carbonate and PP).
Dear Gnanendra
I think the following paper has all the details required
Best Regards
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I feel that addition of any metallic powder (like metallic iron powder) should change the TGA and the DSC curves of calcite. However, I am not able to pin down the references.
Are there some references anyone can help me to identify, which gives the effect of an additive with different thermal properties on the TGA and the DSC curves?
Schawe, J.E., Vermeulen, P.A. and van Drongelen, M., 2015. A new crystallization process in polypropylene highly filled with calcium carbonate. Colloid and polymer science, 293(6), pp.1607-1614.
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Hello everyone,
I would like to compute what temperature my pressed organic powder-based pellet reached after the application of a high voltage (max voltage around 250 V, experiment carried on at room temperature). I though to use joule effect formula and to equate it to the usual Q=m*C*(T-T0). This is however an abrupt method...do you ever know a more reliable one? My material is a natural polymer which exhibit both ionic and electronic conduction. It can be considered as a conducting polymer (low conducting anyway).
Finally, could anyone of you indicate me where I can find a complete table chart showing the thermal properties of solid conducting polymers (particularly the specific heat) ?
Thank you very much.
The measurement will not be easy. If you have a low conductivity powder then you have to use a relatively large electrode surface and thin sample to get measurable current. You can measure the sample temperature only laterally, from the edge by e.g. non-contact thermometry (pyrometers work only at high temperatures), and even that will be loaded with error due to temperature distribution. Another problem can be breakdown within the powder and repoducibility problems related to compaction. The heat capacity of the polymer can be determined by DSC. Heat conductivities of most polymers are within a relatively narrow range in the order of 0.1-1.2 W/mK, see e.g. http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=7510502
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I want to know how I can solve this problem in Ansys workbench?
you can analysis heat transfer analysis by giving the thermal conductivity and thermal coefficient expansion
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Want to predict properties of alloy before actually developing it. Is there any simulator, analytical or numerical method available for the purpose?
With a THERMOCALC software (or other Calphad products such as MTDATA and PANDAT) you can predict the equilibrium thermodynamic properties of alloy, e.g. phase diagram. using such a phase diagram, you can predict the phases developed at a certain temperature and chemical composition, which enables to determine the mechanical and physical properties.
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Dear all,
I have seen many kinds of literature in which researchers talk about thermal properties enhancement of a nanofluid by inserting metal nanoparticle to the base fluid and gave reasons like the enhancement is due to nanolayer formation, due to aggregation of nanoparticles, due to enhanced Brownian motion of the base fluid molecules via MSD etc.
I have two basic questions:
1) Why can't we simply attribute this enhancement to the metal particle only as it has higher conductivity than the base fluid, i.e. due to metal particle we have this enhancement?
2) In metals most of the heat carriers are electrons and molecular dynamics do not calculate electronic contribution in determining thermal conductivity but do rather calculate lattice vibration contribution (phonon contribution) to it which is less than electronic contribution?
Then why researchers have found out the properties with metal nanofluid and rest of them have cited those papers too?
I am really grateful if I could get the answers. Thank you in advance.
You will need ultrasonic vibrator to mix the required nano particles with the fuel, and you can scan a sample of the mixture to show if it homogeneous solution or no. Also, with naked eyes, You can observe the time through which settlement occurs.
for number of samples required, this depends on your operating conditions range, and I prefer that you use dilute solution (φ<1%) to avoid blockage
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I am working on a deep brain stimulation project and wanted to measure temperature rise in the brain when electrodes are inserted. I am looking for a commercially available phantom that has the same thermal properties as the brain for accurate temperature rise measurements.
Please let me know if you know of any such phantom gels.
Thank you!