Calibration - Science topic

This may be a late answer. However, if you need any sort of help related to APSIM simulations I can be of help

Mohammed Almajidi

I appreciate your response,

you wrote " Prepare a series of quality control samples by spiking known amounts of the target analytes and RS into a matrix. Extract the QC samples to prepare them for analysis"

I have some questions:

1) It seems the QC sample preparation is the same with the sample preparation, what is the difference exactly?

2) what do you mean by "series of QC samples" ?

my advisor told me the feature of QC samples is the fact that we can consider their recovery as 100%,, I thought it means we have to do the same process like the sample preparation BUT add the RS after the extraction process (because in this way we know that the QC recovery is 100%)

I dont know, maybe I am wrong. I am working with HPLC-ESI-mass

another question, you wrote I need to spike the RS into the calibration serial dilution too, is there any extraction process for calibration serial dilution?

waiting for your response, Zeinab.

Thank you Katie A S Burnette .

Thank You.

Go immediately for a training internship to some laboratory that uses the ICP-MS technique on a daily basis, preferably for analyzing water samples, and is equipped with a spectrometer that is the same or technically similar to yours.

Study:

1. ICP Operations Guide. A Guide for using ICP-OES and ICP-MS

by Paul R. Gaines, PhD Inorganic Ventures

2.

3. Book https://www.sciencedirect.com/book/9780444594822/sample-introduction-systems-in-icpms-and-icpoes#book-info

And some other very good books and company materials on the websites of spectrometer manufacturers and manufacturers of elemental solutions for calibrating and checking ICP-MS spectrometers.

ZJ

Hi Dr. Rohit Jadhav,

As you mentioned in your question, we need to use the Nernst equation to convert E_Hg/HgO to E_RHE.

In this equation, I recommend you calibrate the Hg/HgO electrode potential using the SCE instead of the SHE.

We recently reported the way to check the potentials of Hg/HgO reference electrodes with different internal alkaline solutions:

I hope it can help you use the Hg/HgO electrode for your experiments!

Hi Brahmari Honnappa,

We recently reported the way to check the potentials of Hg/HgO reference electrodes with different internal alkaline solutions:

I hope it can help you use the Hg/HgO electrode for your experiments!

There are a few steps you can take to try and resolve this issue:

1. Check the source and make sure that it is properly aligned and that the lens voltage is correct.

2. Check the vacuum system, inspect the vacuum chamber and the turbomolecular pump to ensure they are functioning properly.

3. Check any electronic instrumentation aboard the mass spectrometer and make sure that the settings are correct.

4. Check the filament and replace if necessary.

5. Check the mass resolving power at various resolutions and make sure that the settings are as expected.

6. If all else does not work, contact the manufacturer for further assistance.

Dear Serdar Altin ,

please see attached a suggestion for Y-Zr balanced filter sets.

The Y K-edge energy is at 17,038 keV and the Zr K edge energy is at 17,997keV.

The Mo K-apha line is just in between at around 17,4keV.

As I wrote above, the difference of the XRD pattern filtered by Zr and Y XRD_Zr -XRD_Y) will give an XRD pattern with strongly reduced background components which are caused by fluorescence and by Compton scatter.

Balancing of the filters is done by chosing the filter tranmission(s) close to the edges to be equal:

T(Y) = T(Zr) e.g. at 17keV or 18keV or even at 20keV.

From this equation one will have access to the filter thicknesses via:

T(Y) = exp(-µ_y*d_Y) = exp(-µ_Zr*d_Zr) = T(Zr) with µ_Y and µ_Zr being the linear attenuation coefficients of Y and Zr, and d_y and d_Zr being the thicknesses of the filters.

One will get: µ_y*d_y =µ_Zr*d_Zr and thus d_Y/d_Zr =µ_Zr/µ_Y

It turns out^*) that this ratio is very close to 1,5.

An example of the transmission behavior of two of such filter sets is given in the attachment.

The filter set 75µmY & 50µm Zr is a special one, because these filters are commercially available^**).

In a second attachment you will see an overlay of a measured x-ray spectrum a Mo target (35kV)^***) with the 75µm Y & 50µm Zr balanced filter.

Here you see, that

a) there is an excellent match to the Mo K-alpha line and

b) that already a Zr filter alone will help to reduce the Mo K-beta contribution and the Compton background in the high energy region (you mentioned Zr already).

It should be noted here, that the width of the Mo K-alpha is due to the 'poor' energy resolution of the HPGe detector in that region of about some 100 eV, and that the natural bandwidth of Mo K-alpha(s) nicely fits into the Y/Zr edge gap.

A second reason for showing the Mo spectrum, is to provide you an impression onto the ratio of the Mo K-alpha photon flux compared to the flux of the bremsspectrum. So from this spectrum one can see that you will have a lot of Compton scatter from above the Mo K-alpha energy but also from below the K-alpha energy. The balanced filter will effectively cut off the background arising from both parts of energy regions...

*) for µ/rho please see for example the NIST/XCOM data base or the Veigele tables in the CRC Handbook of spectroscopy....

**) I will send you a suggestion for a company including the reference numbers for the foils in a privat massage here via RG.

***) measured by me a lot of years ago...

Best regards

G.M.

Thank you, José Augusto Solís Benites, for the suggestion. Rbacon seems better than Bacon.

regards,

Swagata

Dear Barry Croke & Takuya Iwanaga thank you so much for your suggestions. The modelling results have eventually increased after using satellite derived evapotranspiration data. I have also recalculated the catchments area for the study catchments. The calibration results produced more than 0.8 NSE values. I appreciate your support and time.

Michelle--unfortunately I'm not familiar with Swat Cup software; so I just don't know whether or not Swat Cup can update these two parameters--sorry I can't help you more with this; hopefully someone who works with Swat software will be able to help with your question.

Merck has a carotene standard

Hi Daniel,

When using secondary calibration points, it's highly recommended to use a few. But when you want to incorporate fossils or biogeographics events you should use as many as you can. This because when you implement secondary calibrations it is highly probable to incorporate errors and bias associated to the methodology used with the secondary calibration.

Here at the Institute of Biology-UNAM, there is a very good class on molecular systematics and a module focuses on dating analysis including calibrations. It is offered by Dr. Susana Magallón. I include some of his references in case they help you.

Hope this will help you!!!!

Saludos.

Hi,

I suggest you see the links on the topic.

Best regards

Hi Daniil Marinov

You may make an inquiry at Alfa Chemistry, they offer kinds of good-quality materials.

You can refer to the following link for more information about dCt.

Hello,

you derived the equation from the measurement values having uncertainties. For this reason, the coefficients of your functions are also uncertain. Several approaches are known to transfer the measurement uncertainties to the coefficients, for instance, propagation of uncertainty or the Monte-Carlo simulation. Please take a look to the "Guide to the Expression of Uncertainty in Measurement" to get further information, cf. https://www.bipm.org/en/committees/jc/jcgm/publications

All the best

Michael

Serhii

You have not said what you are measuring, internal or external diameter or length, or width of the part. I used to work in PM fabrication as a Plant Metallurgist, producing hundreds and thousands of bearings, gears, and so on for autos, washing machines, and many more. Thus, let me know.

Dr. K

Seems that Tim Vidmar should know...

Did you ask him?

Dear Roel, Eva, and Alrik,

Thank you very much to all of you for your helpful insights into the topic. I really appreciate your answers, but I see that there might be no easy or single answer as it highly depends on the underlying data set and the research question... However, I am convinced that the method will benefit from this scientific exchange and that we will expand our knowledge in the long term!

Best regards

Katja

Hi Renhua,

I am also wandering why it's still the same then.

Marnel Altius I suggest reading this aricle https://arxiv.org/pdf/2111.10832

I measure 201 points of S parameters from each side, total 402, see the picture attached. Now I found that the shift of S21 changes if I disassemble the scheme and then assemble again, though I had several times the same 3 % deviation. In my last measurements I had -0.21 % and +0.49 %. It looks like it depends on accuracy of assembling.

In any case I am very thankful to you for your interest.@

It should be superior for the same method and linear range, because it shows that the calibration responses increase in a linear fashion. However, this may not be so for a different method or calibration range, even on the same equipment. And like you said, having a quality correlation coefficient alone does not suffice for a robust calibrated method for analysis.

Thank you for your suggestion, I will try that too:-)

See

I believe that equation 6 may be wrong and the signs in both top brackets should be negative.

You can generalise the equations to use any three different calibration loads (I think), but it is best if they are significantly different from each other.

Dear Dr. Nachiket Gokhale ,

linear range is important for accurate detection of your target samples and the interpretation of your results.

For more details, please see the source:

-What is a Western Blot Linear Range and Why is it Important? by LI-COR

Available at: https://www.licor.com/bio/blog/understanding-western-blot-linear-range

My best regards, Pierluigi Traverso.

I am interested in following up on this topic..

Hi Mohammad Mianroodi , welcome to join us for discussion. The propose in designing new material is mainly focuse on the microstructure , but not the chemical composition or other. Moreover, the propose is to design a texture.

Hello,

The graphs show the deviations from 1:1 line (perfect simulation results).

Try the followings which could be if help:

- Adding upper and lower confidence interval limits

- Showing on log-log plot axes

Yasin Hoşgör If I have understood your comments correctly, you are applying cables of different length that were not a part of the calibration setup. Since your antenna simulation results are at the 'antenna port', for the physical antenna measurements all cables upto the antenna port should be a part of calibration process. The measurement plane and calibration plane must be same.

Hope it helps.

Hi

Thanks a lot for all of your useful comments.

When dealing with modeling processes, everything can happen since you cannot predict the performance of a model before you test it on a data set. But you can confidently say that since the models are trained to fit the calibration data it is natural that the calibration efficiency (precision) is higher than validation.

Furthermore, I don't think you would find such a paper. I mean, to be honest, the subject it is not important to try to find a way to analytically prove whether the validation precision of a modeling process will tend to be lower. What will be the gain of such a result? Take also into account that it is not even certain that such proof even exists.

Moreover, to make a robust statistical claim we need to analyze a very huge set of models with a very much more enormous set of data. It is virtually impossible to study every model using every kind of data for every purpose possible.

I think if you stated more precisely, what you exactly you are after you definitely can find your answer here.

Cheers!

First of all, thank you for your response. Independently if we use OpenSees or any commercial program of three-dimensional finite element, when we work with cracking from the continuous function focus we have a problem when we introduce numerical cracking. E.g. if we work with fracture energy Gf and we use the displacement of the open crack Wu, it is known that the cinematic equation for the strain calculus in the FEM formulation needs to be divided by the characteristic length strain_u=strain_cr+(Wu/Lc).

Suggest the following paper:

Hi Nagarajan, Theoretically, you can move the target closer to the off-axis parabola to replicate a finite conjugate. However, the further the conjugate is away from infinity, the larger the aberrations become. The magnitude of the aberrations depend on the focal length of the collimator and the aperture of the camera lens you are using. You really need optical design software to quantify the aberrations. A simpler option is to not use the collimator but to set the target 20m from your camera. If you do not have access to a controlled area this long, it is generally easier anyway to set up a flat mirror approximately half the distance required and then the target can be placed close to the camera.

This is the typical signature if a bad contact (loose connector) somewhere in your setup

Fateme Khoshtarash for PLS using python, pls follow this https://www.kaggle.com/code/phamvanvung/partial-least-squares-regression-in-python

If you need any technical help, pls let me know.

Best !!

AN

Please have a look at section 13.2 in 6.6 of the manual; https://classes.engineering.wustl.edu/2009/spring/mase5513/abaqus/docs/v6.6/books/gsa/default.htm?startat=ch13s02.html

As Napoleon almost said " give me preferably lucky researchers"

Low recoveries are typically due to too low a combustion temperature but high recoveries must be a calibration issue

Nacer Dilmi The price/performance ratio of the CILAS 990L is the best of any system on the market. Particles of diameters ranging from 0.2 to 500 m can be measured. You can see the manual available with your device.

Marcus Ferreira I suggest reading these articles:

1.

2.

3.

4. https://www.sciencedirect.com/science/article/pii/S0003267021005973

5.

That's right, it is necessary to have information on observed data, good engineering practices require that the model be calibrated.

The surprisingly similar question to that of :" What is the calibration system for phosphomolybdenum based antioxidant activity?"

Dear Newton Muhury

you should adjust the simulation period in cio file with the Calibration period in observed data files and in extraction file as well

for example if your simulation period is from 2001 then you need to prepare your observed data from 2001 and if you consider 2 years warm up the observed data must be from 2003.

the default observed data in observed and observed_reach files is just to show you how to prepare your own observed data you cannot use it to calibrate your model in your study Area

best of luck

OK, it looks like you have indeed highly correlated data.

Is it that you wonder whether the high correlation is indeed fully an r^2 of 1?

Perhaps at play is that you consider the regression results as shown in a graph in Excel, which I believe only shows 4 digits of precision for r^2.

You might want to try using the formula LINEST instead, which shows greater precision in its results. Or as Oluwaseyi Ayorinde Mohammed suggests: use different software than Excel. EViews or Stata may be good for your purposes, but if not, or if difficult to acquire, you can also use open source software such as R/RStudio or Python.

Total Antioxidant Capacity (TAC) assay by phosphomolybdenum method that based on the reduction of Mo (VI) to Mo (V) by the sample analyte and subsequent formation of a green phosphate/Mo (V) complex at acidic pH, usually detects antioxidants such as some phenolics, ascorbic acid, α-tocopherol and carotenoids (Prieto et al., 1999).

Prieto, P., M. Pineda and M. Aguilar, 1999. Spectrophotometric quantitation of antioxidant capacity through the formation of a phosphomolybdenum complex: Specific application to the determination of vitamin E. Anal. Biochem., 269: 337-341.

When you are not using the extensometer the displacement is obtained from the crosshead or actuator. In such cases we do not get only the change in dimensions of the specimen , instead some part of machine displacement is also involved since the specimens are gripped away from the gauge length. But when we are using extensometer only the change in displacement within the gauge length is recorded which is somewhat more correct provided the extensometer is calibrated properly.

It is always advisable to use extensometer data as it can capture the change in resistance due to change in gauge length when the specimen is subjected to loading. Once a test is done with the extensometer compare it with literature data for material properties like Youngs modulus, yield strength and ultimate strength. If the results are comparable then the data is correct. Do it at first for specimen which have existing literature data.

Once your extensometer results are validated you can carry tensile test without extensometer. In this case you need to calculate the actual specimen change in length. This can be done by finding out the machine compliance. In tests with extensometer compliance of the whole system is given by machine compliance +specimen compliance. You need to find out this machine compliance , find a relationship of machine compliance with load. Machine compliance for a particular fixture for a particular machine does not change. So if a test is done without extensometer then you can use the relationship of machine compliance with respect to load from the previous tensile test where you have used the extensometer and find out the machine displacement. Subtract it from the total displacement and you shall get ypur desired result.

For more information you can see instron documents for calculating corrected displacement using machine compliance.

Hope this helps you.

I think it is only appropriate if your using Collection 2 level 2 Landsat satellite images that has already been atmospherically corrected. But I will advise that you perform all the corrections on the level 1 imagery for an enhance results.

Hi Darren

to check the viability of a reference electrode you need to do

Perform an EIS test with a two-electrode system. Choose Galvano Mode EIS (GEIS) to avoid polarization of your reference electrode. The reference electrode (working electrode) and a platinum or gold electrode ( counter electrode. The impedance of the reference electrode should come below 1 kΩ. If it is higher, then it is not viability. perform an EIS test with a two-electrode system. Choose Galvano Mode EIS (GEIS) to avoid polarization of your reference electrode.

Hi Noel W Davies,

Sorry for not responding until now (busy days).

Can you please explain how it well help?

The former have been more extensively tested than the latter, for the time being.

Seed drills of different makes are fitted with seed metering devices to increase or decrease seed rates within specified limits. First, fix seed metering lever in appropriate seed rate delivery notch measure circumference of drive wheel (Cd). Measure width of the drill (Wd) or else multiply the number of tynes with distance between the two tynes. Put seed material in seed- box and rotate drive wheel manually ten full rotations and collect seed delivered trom each tube separately in polythene bagd. Weigh seeds in each bag and also determine pooled/ total seed weight (Sw). If the difference in seed weight between individual delivery tubes more than 10% contact the machinf for adjustment/repairs of the drll. Repeat operations with fertilizers in box to find weight of fertilizer material (Fw), delivered in ten full rotations of the drive wheel as described. Calculate seed and fertilizer application rate per hectare using the following formula:

Seed rate (kg/ha) = (Sw/ Cd x Wd)

Where, Sw = Total weight of the seed released in 10 revolutions (gm)

Cd = Circumference of drive wheel (m)

Wd = Width of the drill (m)

Similarly, fertilizer rate (kg/ha) can be determined using the same total weight of fertilizer released in gram (Fw) in place of total weight of seed (Sw).

It is cautioned that calculated seed and fertilizer rates can differ by 5% from the actual rates due to drag and slippage of the drive wheel depending upon the soil moisture, surface roughness, presence of crop residues and field level. Carry out minor adjustment in seed/ fertilizer rates by actually testing drill in the field.

The simplest and most accurate, also working with a very high speed (many thousand measurements in one second) method of the measurement of solution in which the concentration of one substance is changing (unknown) is the measurement of sound speed in this solution.

This can be made with extrem accuracy. Requires only calibration if the dependance of sound speed on the concentration is not known. We have many such systems for chemicists, that are controlling the concentration of dirrerent substances or their processes.

Dear Harsh Upadhyay,

Interesting question. In addition to the very useful comments and replies from colleagues, I would like to add some observations and comments. The calibration and validation strategy depends on different factors, such as the purpose of the modelling and possible final application, the availability of data and the hydroclimatological conditions in the studied catchment(s).

The modelling purpose can be very general (e.g. simulation of hydrological regime and behaviour of a catchment), specific (e.g. low flows) or supporting water systems and infrastructure design (extreme, non-observed conditions) and future impacts (e.g. due to climate change). Calibration and validation strategies for general purposes can be more straightforward by using the split-sample test and dividing the time series in two parts, indeed generally somewhat more data for calibration (e.g. 2/3) than for validation. Specific purposes and support for design and impact assessment require more tailor-made approaches showing the robustness of the model. For instance, for flood design purposes one would like to show that the calibrated model can also be used for more extreme conditions than the calibration conditions. Hence, one might select the calibration and validation periods in such a way that the validation period includes more extreme events than the calibration period. In this and similar cases a so-called differential split-sample test is therefore more appropriate. Similar reasoning applies for climate change impacts studies, where you might want to show that your model can also be used for changed climatic conditions. This can be (partly) achieved by selecting a validation period with (hydro)climatological conditions more similar to the expected changed climatic conditions than the calibration period.

Data avaliability obviously determines what is possible in the calibration and validation. When for instance streamflow data are not sufficiently available, you might look for alternative data regarding other output variables such as actual evaporation (e.g. based on satellite information) or state variables (e.g. soil moisture, snow and groundwater). Different calibration strategies for multiple variables (and objectives) are available in the literature, see for instance .

Recommended splits for calibration and validation periods (e.g. 50-50 or 70-30) will also depend on the hydroclimatological conditions in the study catchment (e.g. the occurrence of dry and wet periods) and the hydrological model used. The systematic study mentioned by Mehmet Cüneyd Demirel provides a nice example of the detemination of the optimal data length, but results obviously depend on the hydroclimatological conditions, the catchment characteristics and the model used.

Good luck,

Martijn

We also had a problem and after consulting with the experts of Kiagene Fanavar Company, who are based in our university, we finally decided to buy a MIC machine. I will send you the company link and email, maybe they can help you

Dear Xiaojin Li ,

you may have a look at the answers of a similar questions here on RG:

Best regards

G.M.

Vadym Chibrikov

Hence the scallops are not coated with a polysaccharide. If with glue, then it was necessary to write with what kind of glue. Your source is not readily available to consultants.

Please respond if any one has idea?

Dear Dr. Celia Fuentes Chust ,

in general, the input impedance of a pH meter is so high that the electrode should not be affected by the ignition or not of the instrument connected to it and therefore the life of the electrode is therefore not modified in keeping the electrode on or off. instrument.

The electronic part can be considered to be affected by the greatest electrical and thermal stresses upon switching on and off, while an instrument constantly switched on has a very slow but inexorable aging.

In the case of a pH meter, it is therefore necessary to rely on common sense based on the actual methods and frequency of use.

In the case of occasional use, it would be better to turn it off and turn it on only during the days of use, considering that cleaning, methods of use and conservation of the electrode over time are much more important.

My best regards, Pierluigi Traverso.

I think you do mistake in local input entering. Please check one by one including units. To be assure, please dont change no inputs and run the software. If the results seems reasonable, then based on default inputs, you can enter your local inputs.

At 0.5 ppm (ug/mL) you need a more sensitive detector like MS (in general it is about 1000 X more sensitive than DAD/PDA). Even at 4 gummies in 10 mL water we are talking about 20 ug in 10 mL or 2 ug/mL (assuming each gummie is 5 g). This calculation does not involved the mass you are injecting on your column (which is another factor)! BTW the old AOAC had a colorimetric procedure for B12 that used Bathophenantroline.

Anne Nordli Yes, I solved... I remember there was a wrong defined variable. But I don't remember how I solved it. If you want, maybe we can speak. Let me know in such a case.

Your question is very abstract... Can you make it a little bit more concrete?

Dear Antara,

First of all, it would be better if you specify the other chromatographic conditions related to the analysis in more detail, such as column, detector and analysis time.

However, since there is no methanol in the mobile phase, I think you can get better results if you remove the methanol from the sample. It is always preferred that the sample is in a solution similar to the mobile phase.

Good luck

Kind regards

The data shown in the two jpg images are not consistent. Beers law is widely used for solution spectrophotometry. It holds well as long as the absorbance is 1.0 or less (range 0.000 to 1.000). It is possible to have absorbance above 1.000 but the relationship between the measured absorbance and solute concentration is rarely a simple linear function. Absorption = -Log₁₀(T). when T=1.000 then A=0, when T=0.100 then A=1.000, when T=0.010 then A=2.000, when T=0.001 then A=3.000. It is difficult to read higher absorbances than about 3.000.

The concentration of interest, given in the tabular display is 30.50% or 0.0305 (as suggested by Mayerhoefer. But the equation given in the Excel worksheet image is Absorbance = 0.108 + 0.554 x Conc. If one substitute 0.0305 for the Conc variable, the equation yields an Absorbance of 0.125. Either the calibration table is not the correct table or the calculated Absorbance was obtained from a different calibration, such as proposed by Van de Moortel.

Katia Souza These manuals might help:

1. https://www.promega.de/-/media/files/resources/profiles-in-dna/601/spectral-calibration-or-making-a-matrix.pdf?la=en

2. https://tools.thermofisher.com/content/sfs/manuals/4401661.pdf

3. https://strbase.nist.gov/pub_pres/ForensicsNIST-ABI3500.pdf

4. http://afdaa.org/2013/wp-content/uploads/2013/01/AFDAA-CE-Updated.pdf