Ayoub Najem

19 Questions 4 Answers 0 Followers

Questions related from Ayoub Najem

Is DEL ( DNA Encoded Library ) a good field for job opportunities in the futur ?

Do you think that DNA encoded libraries (DELs) holds promising future prospects and job opportunities ? I will be very thankful to receive your suggestions

04 June 2023 1,474 1 View

Anyone has encountered this kind of 13C NMR peak shapes?

Please, do you have any experience with this kinf of peaks in 13C NMR chromatogram? Do I have to consider 2 carbons or just 1 for each peaks shape?

28 February 2022 2,252 6 View

What is the suitable TLC solvent to separate polymethoxyflavones from plant material?

I'm looking for the isolation of polymethoxyflavones from my crude extract. Which TLC plate is better, normal or reverse phase? And which kind of solvents giving a best separation? Anyone...

08 October 2021 2,489 8 View

How to determine the percentage of essential oil constituents by GC MS ?

I would like to determine the proportion of every constituent of my essential oil. I made GC MS and the the qualitative analysis by recognising the different constituents presents using...

23 September 2021 1,902 3 View

Could we use computer simulation or modeling to test a natural inhibitor against corrosion?

Silico experiments are considered the cheaper way to test and examine a substrate against an activity. In corrosion science, could we use software, a computer simulation, or modeling to...

23 June 2021 2,532 4 View

Any Platform or course to master NMR spectroscopy?

I'm working in the field of plants, isolation, and structure determination of biologically active natural compounds. I need NMR of proton, carbon-13, 2D,... Any suggestions in this regard; free...

13 May 2021 2,590 5 View

Does the boiling point of essential oil constituents go necessarily with their retention time?

The boiling point of α-Pinene surrounding 155 °C and that of β-Pinene surrounding 166 °C. And we find always the α-Pinene before the β-Pinene. Does the boiling point go necessarily with the...

10 April 2021 5,601 3 View

Can I use UV- liquid in anticorrosion activity?

After emersing my material (mild steel ) in the different present concentrations tested in the anticcorosion activity. I pull out the material and I analysed the liquide on UV-liq. How can I...

09 April 2021 6,194 3 View

What is the best column for analyzing essential oil through GC-MS?

I'm using an HP-5MS column with a length of 60 m, but in the literature I find so many papers using 30 m! Firstly, what is the best column ( HP-5MS, HP-5, DB-5, ...) for characterizing essential...

06 April 2021 3,585 7 View

Does tween have an effect on the anti-corrosion activity while we use it to make essential oil well mixed with acid?

We use either tween 80 or tween 20 to mix the essential oil with acid while we are preparing the stock solution in order to carry out the test of anticorrosion activity in an acidic medium. I'm...

27 March 2021 3,465 2 View

Any software to predict the antioxidant activity of essential oil from the chemical profil?

As we know, an essential oil is a mixture of components playing a pivot role in various domains. I'm carrying out the antioxidant activity using in vitro tests. Before doing this task, can we...

26 March 2021 9,842 3 View

How increasing in temperature decrease the efficiency of my inhibitor on corrosion of mild steel?

The temperature has a major effect on the decreasing anticorrosion activity of an inhibitor( organic component, essential oil...). What is the mechanism happening between my substrate (mild steel)...

24 March 2021 2,042 3 View

What is the benefit of using essential oils instead of botanical extracts?

As we know essential oils don't contain heavy molecules and significant active chemical compounds as polyphenols, alkaloids...Furthermore, when we extract the essential oil, we obtain a tiny...

23 March 2021 9,066 5 View

Why we explain always the activity of essential oil by synergistic effect ?

Can we give a little bit whether an explanation or interpretation of the potential played by essential oil against free radicals for example without saying only the synergistic effect? Is there...

21 March 2021 7,512 7 View

Why we don't use Electrochemical Impedance Spectroscopy (EIS) when we are testing the effect of temperature?

Almost all studies reported in the investigation of the potential of a product (organic, inorganic, or plant extract) on the corrosion inhibition don't use the technique EIS (Electrochemical...

20 March 2021 9,345 5 View

How can we transit the use of essential oil as a natural inhibitor on a large scale ( the industry)?

I want to have an idea about the way to put natural inhibitors into practical use to reduce the corrosion rate. Where we can apply those inhibitors for example? Can anyone give me a company using...

19 March 2021 2,132 4 View

Why FRAP method is not considered as a valuable method as DPPH and ABTS for the antioxidant assay ?

Recently, FRAP (Ferric Reducing Antioxidant Power Assay) is not accepted by some journals for the investigation of the antioxidant power of a sample like essential oil! I don't know the reason...

19 March 2021 9,170 4 View

Are essential oils containing ketones not toxic?

In a lot of studies, they consider essential oil as non-toxic, whereas it contains a significant amount of ketones and those are toxic! for example, in absinthe we find thujone. And this plant is...

19 March 2021 8,424 2 View

What is the interest of studying essential oils on the inhibition of corrosion?

I'm working on the field of valorization of natural resources (fruit waste, plants) by the extraction of essential oil and botanical extracts. I do the application of those recovered substances on...

18 March 2021 4,478 4 View