Is it possible to obtain a negative cronbach alpha?

Good evening everyone. If a questionnaire has 4 factors measuring different constructs as for example CAMI questionnaire measuring attitudes toward the mentally ill that has four factors:...

18 February 2021 3,223 3 View

Where to find data set for big data analytics ?

I am looking for a data set (preferred to be spatial data) in order to apply big data analytics on it, can you help me to find such a data set please?

05 January 2021 4,860 4 View

How do I properly normalize spectra/peaks for comparison (Photoluminescence and Electroluminescence) ?

Hello, This questions pertains to comparing peaks from spectra of 2 or more different samples in a fair way through normalizing I know Origin normalizes based on the highest peak however if I...

12 December 2020 403 1 View

Can xylose be formed from fructose over acid catalysts?

I am new in the field of sugar chemistry. I wanted to know if it is possible for fructose to be converted to xylose over acidic conditions. I saw in some schemes a pathway from fructose to xylose...

07 December 2020 5,247 3 View

What is exact impact of pH on preparation method of nanoparticles? why some nanoparticles are synthesized in ACIDIC pH while others in alkaline pH?

I am trying to prepare Cerium oxide nanoparticles. literature suggested the acidic pH of the reaction. what is the reason? what is the mechanism if so

28 November 2020 8,825 2 View

Estimate / Predict remaining useful life of a bearing without data of previous failure?

Hello, I am trying to write a program in Matlab to estimate the remaining useful life of a bearing without data of a previous failure. Do you think this is possible? I was thinking to use the...

27 November 2020 9,863 3 View

Two way ANOVA with non normal data?

Good afternoon everyone. I would like to know your oppinion or advise for the following: I would like to compare the results of a variable measured with a likert scale. I have two (or three)...

19 October 2020 4,564 4 View

Comparing two independent groups with very different sample size?

Hello eveyone. I would like to know your oppinion on the following. Do you think that it is adequate to compare two groups with very different sample size and non normal sample distribution? for...

19 October 2020 8,475 4 View

Why I obtain very high surface area under HMF peak in HPLC even with suitable dilution?

I am converting Fructose into HMF, Levulinic acid and formic acid are possible side products. I analyze the data via HPLC, bio rad column, I got nice results for some reaction set. But when I...

23 September 2020 6,375 7 View

What is so special about graphene?

Why is graphene so important?

18 September 2020 3,857 9 View

How is single molecule's fluorescence lifetime depending on excitation density?

It is known, that the fluorescence lifetime of an ensemble of molecules being in close vicinity can change, as intermolecular processes between excited chromophores (e.g. superradiance,...

28 October 2020 7,656 3 View

Iam looking for a laboratory space to synthesise a novel organic chromophores for dye sensitized solar cells??

Iam a Ph.D student working on synthesis of novel organic chromophores for dye sensitized solar cells, the organic chromophores to be synthesise will be based on indoline, benzothiophenes,...

21 May 2020 2,946 3 View

How can I measure antioxidant capacity of cosmetic lotion?

Dear scientist: I want to measure the antioxidant capacity of cosmetic creams and lotions with the DPPH and ABTS methods, but I am not sure how to prepare the samples. Will dissolving them in a...

10 February 2020 3,597 4 View

I want to carry out analytical method development method for gadobutrol drug a MRI contrast reagent . Not able to get uv in these .could anyone help??

I not able to carry out uv response on these could any one suggest how to take uv as these compound dont have any chromophoric group present in these .

09 February 2020 3,291 3 View

How to calculate percentage inhibition in ABTS method?

27 January 2020 2,632 3 View

How to calculate percentage inhibition in ABTS method?

31 December 2019 8,117 3 View

After adding stop solution (sulphuric acid) in reaction mixture of HRP assay with TMB, yellow color becomes brighter. What is the mechanism?

Yellow colour, before the reaction is stopped, is due to the formation of oxidized TMB, which isTMB(2+). The reaction is stopped by degrading HRP, but are there any further oxidations happening?...

13 December 2019 269 3 View

After adding stop solution (sulphuric acid) in reaction mixture of HRP assay with TMB, yellow color becomes brighter. What is the mechanism?

Yellow colour, before the reaction is stopped, is due to the formation of oxidized TMB, which isTMB(2+). The reaction is stopped by degrading HRP, but are there any further oxidations happening?...

11 December 2019 376 3 View

I am preparing ABTS solution in Buffer 1 mM concentration of ABTS it appears in light green color. what colour it should have?

how can i prepare ABTS solution for laccase assay?

09 October 2019 3,933 1 View

Which method should choice of method to calculate antioxidant activity of plant extract ?

#DPPH #ABTS #FRAP #PFRAP #CUPRAC #ORAC #HORAC #TRAP #Fluorimetry

09 October 2019 6,807 3 View