Chemistry - Science topic

Cf. H. Simchi, Sh. Bahreani, M.H. Saani, "Cleaning InSb wafers for manufacturing InSb detectors", Eur. Phys. J. Appl. Phys., 33, 2006, pp. 1-4.

Dear Mohammad Javaherian many thanks for the interesting technical question. It's interesting to see that there are already some rather differing answers. I agree with Sebastian Jung in that the "alpha effect" does not play any important role here. I don't see a mesomeric effect of the methyl groups either because the phosphorus atom has a free electron pair and not a positive charge. Instead, the electron-withdrawing oxygens in trimethylphosphite will lead to the effect that the free electron pair at phosphorus has more s-character, making P(OMe)₃ a weaker nucleophile. In contrast, the free electron pair at the P atom in trimethylphosphine has more p-character so that PMe₃ is the stronger nucleophile and a better donor ligand toward transition metals. For some very useful overview on the different properties of various ligands please have a look at the following article:

I am not sure if rhodamine b are sensitive to substances like washing, buffer or even PBS. Make sure the fluorophore is hold tight on the sample.

Dear Amit Kumar Acharzo

Has your pharmacotechnical development taken into account the properties of your active ingredient? and whether it is compatible with many aggregating and / or gliding excipients?

Dear Arina Levina thank you for your interesting technical question. The question would certainly get more qualified answers if you explained what you mean by DES. I had a hard time finding it out. When you check the Wikipedia entry on the abbreviation DES you find no less than 26 different meanings of DES on the English page, from "Data Encryption standard" to "Deep Eutectic Solvent" (https://en.wikipedia.org/wiki/DES).

Since you were talking about hydrogen bonds in your original question I assume that in your case DES stands for desloratadine, right?

In this context, please have a look e.g. at the following useful link which is freely available as public full text:

For the stability of desloratadine in water, please also see the following relevant article:

It could also pay off to use the "Search" function of RG to find and access other useful references on this topic. Just search for "desloratadine" and then click on "Publications". This will result in a large number of interesting articles:

Nanoparticle-Based Strategies to Combat COVID-19

Hi Pranav, could you find the answer?

Interested question. In my opinion the best superplasticizer that can handle hydration processes under nano scale. In many cases capillaries filled with nano particles without any water reaching possibility. I think the best superplasticizer must manufacturing to overcome this problem specifically!. Then all nano materials react with Ca(OH)2.

My regards

Dear Ekaterina E. Khramtsova please have a look at the following useful link:

Hi Shaun! I'm not sure where you are located, but I would recommend researching Research Experience for Undergraduates (REUs) in the U.S. Many schools here offer a summer internship program for students from another school. I am unsure of their stance on international students though.

If you are a U.S. citizen, then I highly recommend looking into internships with NASA if they align with your interests. You can learn more about those opportunities at intern.nasa.gov.

You might look up some companies that you are interested and reach out to them specifically. The easiest way to do that might be to find employees of the company on LinkedIn and reach out to them. They might be able to point you in the right direction on how to get an internship with their company.

Good luck and I hope this helps!

Dear Natrawee Khetwunchai thank you for your very interesting technical question. Please find cited below some research articles in which the mechanism of gold leaching using Fe₂(SO₄)₃ has been investigated:

1. Recovery of Gold from the Refractory Gold Concentrate Using Microwave Assisted Leaching

(see attached pdf file)

2. Bacterially generated Fe₂(SO₄)₃ from pyrite, as a leaching agent for heavy metals from lignite ash

This article is freely available as public full text on ResearchGate.

3. Leaching kinetics of gold bearing pyrite in H2SO4−Fe2(SO4)3 system

(see attached pdf file)

Hi Taufiq Ahmad . From literature, it looks like the BCA assay works only with secondary amines. As the secondary amines form a colored chelate complex with cupric ions (Cu2+) in an alkaline environment and form Cuprous (Cu+) ions. The Cuprous ions form a complex with the BCA assay.

In experience I have found a linear response of BCA assay with Primary amines too. I do not know what the exact mechanism is for that. Did you find it out?

Anurag Roy perfect question and you can surely have a look at this blog with many experts from around the globe and they will help you for sure

you can also find some books listed there too,....

Thank you both!

Hi Gregoire,

Thanks a lot for the information and the links! Really helpful!

Cheers,

R

It is true that transparent materials may have imperfections that result in sub wavelength fluctuations in the density and produce Rayleigh scattering. For example, this is an important component of the transmission range in optical fibers. True also for molecular scattering in the atmosphere.

However, if you are asking about the penetration depth into a homogenous material with some degree of absorption, absorption is NOT described by Rayleigh scattering. Instead, see

Absorption is the resonant interaction of the EM wave with some allowed energy transition of the charges in the material that has a transition dipole moment. Because this is a resonance phenomenon the strength of the interaction, i.e. the absorption probability, can have a lot of shape as a function of wavelength (energy). Near a discrete transition the absorption may increase as you shorten the wavelength and then decrease again as the energy increases further past the absorption. (Absorption bands). The absorption probability results in a Beer’s law exponential decay of the field. So you can see the penetration depth may decrease or increase with shorter wavelength depending which side of a discrete absorption you are on. However, there is also an intrinsic inverse dependence on wavelength. (See wiki article) if the absorption is almost constant with wavelength (and so the complex index is constant) as is common above the band gap energy of semiconductors or transparent materials, the intrinsic 1/lambda dependence becomes apparent.

First I would like to ask you a question. I have doubt on the composition of your ink, how uniform?. If your ink preparation is not uniformly dispersed, your loading on GCE may not be uniform. Thus I recommend the following. Amount of catalyst to solvent ration (e.g. m/v), choice of solvent and binding reagents, cleaning GCE strategy and drying systems must be carefully manipulated. For example, if the catalyst added to the solvent system is too large, the distribution/solubility of your catalyst may not be good (try to tune this too e.g. catalyst/solvent ratio 1/1, 1.5/1 and so on). As recommended by other researchers please try ethanol as a solvent and Nafion as a binding agent, here the amount of Nafion also matters, to my understanding should not be higher than 30 μL to obtain uniformly coated GCE. Moreover, if you keep your electrode for long time on air for drying (after loading your ink), your electrode may not be uniformly coated too. Alternatively, you can use 40 or 60 oC oven for short time to dry your electrode with required amount of your catalyst (e.g. 5 μL on 3 mm diameter GCE). Hope this will help you a little.

Dear Asfak Patel thank you for your interesting technical question. It is known that the contact of metallic copper with sodium chloride solutions in the presence of oxygen (air) can lead to corrosion of the metallic copper. Did you check the composition of the precipitate?

For some general information about copper corrosion in NaCl solutions please have a look at the following useful articles:

1. Investigation of copper corrosion in sodium chloride solution by using a new coating of polystyrene/g-C3N4

This paper is freely available as public full text on ResearchGate.

2. Influence of pH and Chloride Concentration on the Corrosion Behavior of Unalloyed Copper in NaCl Solution: A Comparative Study Between the Micro and Macro Scales

(see attached pdf file)

To ensure understandability, reproducibility, and replicability, the research methodology must be clearly spelled out and expatiated upon. In other words, all procedures carried out in a study must be explained in detail in the methods section, leaving no room for whats or whys. The following could render more insights.

PLOS. (2021, February 26). How to write your methods. https://plos.org/resource/how-to-write-your-methods/

USC Libraries. (2021, March 18). Research guides: Organizing your social sciences research paper: 6. The methodology. Research Guides at University of Southern California. https://libguides.usc.edu/writingguide/methodology

Thank you for sharing idea Madhukar Baburao Deshmukh

Good afternoon Mrs / Ms.

What kind of the specific information you probably need ?

Jason Wilt, Because no one knows the degradation products have higher or lower boiling points than the mother amine, I recommend that you use at least two receiver flasks to eliminate both lower and higher bp materials together. Imagine you distill 25 mL, I usually take the first 3 mL and last 1-2 mL each in a same small flask together. Collect the first, low bp portion till the gas temperature becomes constant. Then, you will have a main fraction in a big flask. The gas temperature tends to decrease during the last half of your distillation, heat to keep the gas temp. It's time to stop collecting the main fraction and to change the flask to the drain receiver, if the gas temp. goes down even if the mother liquor is heated. After cooling the whole system to rt, introduce argon or nitrogen to the system, to break the vacuum. Do not dry up the mother flask. Stop the distillation before the mother, heated flask loses all the liquid, because there may be peroxides there. (Dried peroxides are said to be explosive sometimes when they meet oxygen, at high temp. That's why you should cool the system before stopping the pump. You also use argon not air. All of these avoid the danger.) Put a septum cap with an argon balloon to the main fraction, and by a syringe or a cannula, transfer the freshly distilled amine to ampules which are already dry and have argon inside. Close the ampules immediately by flame, and keep them in a dark fridge till you use them, after you warm up to rt. Refluxing with CaH2 for 1 h will usually be done before the distillation. Good luck!

Usually the elements are selected. Those, elements assembled in a group should not have very different parameters (for example, operating voltage, internal resistance). If, for example, during series connection one of the elements has a relatively high internal resistance, then it will limit the entire series, and so on. If you have access to a large number of same elements (for example, in manufarture), then it is not difficult to collect the required quantity for assembly, but with a limited quantity, this can be a problem. In the "professional case", the elements are connected in a circuit using active components to neutralize their differences, both initial and arising during the discharge process.

Dear M. Mozammel Hoque,

I think that Book Organic Chemistry Morrison & Boyd is good for you.

Kind regards

Dear Ahmed Lotfy

Thanks for the response. However, after considering all of the criteria you mentioned, we have to choose a proper journal for our paper.

Let me put the question in this way, what makes a journal better than others!?

In the main question, I gave three examples; could you please choose one of them?

I agree with you Mr. Naimish Kumar Verma.

Dear Lokesh Murali thank you for this interesting technical question. I only found a references in which the combination of nickel selenide with Ti3C2Tx has been reported:

This paper is freely available as public full text on ResearchGate.

Something that has to do with study involving production of nanocomposites for the production of fire resistant parts or shear resistant parts of mechanical equipments.

Production of Biodiesel from non-edible composition of biomaterials by transesterification

Dear Gabris Mahamid thank you for this interesting technical question. As an inorganic chemist I'm not really familiar with this topic, but I can try to suggest to you a few potentially useful articles. Please have a look e.g. at the following papers:

1. Can a single molecule trap the electron?

This article can be freely downloaded as pdf file from the general internet.

2. Functional group dependent dissociative electron attachment to simple organic molecules

This article is freely available as public full text on ResearchGate.

bioinorganic chemistry and applications

I think these attachments can be useful for you

Maybe that helps you: https://typeset.io/formats/elsevier/analytica-chimica-acta/b2233832fb58f1aaa72b712a67a0cc69

I am guessing some kind of click chemistry so some kind of amide or alkyl group that would then be complementary to group on what you attach to.

A safety data sheet (SDS) from one manufacturer attached. This material is very high risk and requires special handling and storage. It does not say on the SDS that it is incompatible with organic peroxides, but in contact, it will release hydrogen gas. I would recommend looking for a safer substitute if possible.

The University of Jena, Germany, and the New York State College of Ceramics at Alfred University, in the USA, are among the most specialized and traditional centers in glass science.

The Federal University of Sao Carlos, in Brazil, also offers very equipped facilities, if you prefer a tropical country.

Of course, there are a lot of other good institutions... it depends on the subject you are interested in within the topic of glass chemistry. For example, if you want to research Bioactive Glasses, the Imperial College London has nice researches in this field.

Both the PBE and PBEsol are first-principles generalized gradient approximations (GGAs). A simple modification of PBE is the PBEsol functional, which differs from PBE only in two parameters, and is designed to improve upon PBE for equilibrium properties of bulk solids and their surfaces. The main difference between them is that they are based upon different selections of exact constraints to satisfy.

At the GGA level, but not at the higher meta-GGA level [Meta-GGA DFT functional in its original form includes the second derivative of the electron density (the Laplacian), whereas GGA includes only the density and its first derivative in the exchange-correlation potential], one can at most satisfy two out of the following three constraints exactly:

1. second-order gradient expansion for exchange.

2. second-order gradient expansion for correlation

3. the local spin density (LSD)-like linear density response of a uniform electron gas.

The PBE satisfies numbers 2 and 3 but not 1, whereas the PBEsol satisfies number 1 and compromises between numbers 2 and 3.

From the performance perspective, the PBEsol describes more correctly the stereoelectronic (SE) effects in many hydrocarbons than many other DFT functional approximations, applies to densely packed solids, and is also useful for large organic molecules (in the absence of free atoms). On the other hand, although no GGA without a dispersion correction can account for long-range correlation, the PBEsol (after the error cancelation between exchange and correlation) can apparently account for medium-range interaction better than the PBE.

The best way is to measure X-ray or electron diffraction accomplished with photoluminescence. It will give both insights into the nature and the quality of surface improvements.

Nobody forbids anyone to look for and use other relationships of rate constants on temperature than the Arrhenius equation. In design, it does not matter whether the equation/function used has a physical meaning or is merely an empirical equation. In science, however, one should not assign physical meaning to equations and thier parameters that they do not have. Unfortunately, this is a common procedure.

Dear Daniyal Ahmed just in case that this question is still of interest to you: The article cited below contains a detailed description of how to make oleum in the laboratory:

Personally I would suggest to buy oleum from commercial sources as it is an industrial product manufactured on a large scale.

Dear Talal Ashraf there are two potentially useful article on this topic available as public full texts right here on RG:

1. Predicting Feasible Organic Reaction Pathways Using Heuristically Aided Quantum Chemistry

2. Neural networks for the prediction organic chemistry reactions

Also, see the following RG links.

Follow

Hi Leonard, I would suggest you search review articles on your topic first, journals like the Review of Educational Research could be a good start to find the foundation studies for your proposal. Good Luck with your research proposal!

-Tingting

Dear Ethan,

There is a similar question which were posted in the research gate forum. This could answer your question. Please see the following link

Best wishes

Xuhua

Since the pKa's of acid and base are far apart, you probably start with a near neutral solution before you add the extra weak base. Then you pH goes up into the alkaline area.

Normally you prepare a buffer by either using a weak acid and adding about half of its concentration of a strong base or vica versa. I do not understand that you call a mix of a weak acid and a weak base a buffer.

What is the purpose of your 'buffer' ?

Sodium metabisulfite (Na₂S₂O₅) dissolves in water as sodium bisulfite: Na₂S₂O₅ + H₂O → 2NaHSO₃. Sodium bisulfite is converted to sodium sulfite (Na₂SO₃) by

NaOH. The solubility of sodium sulfite (Na₂SO₃) in the alkaline solution may have been exceeded due to the common-ion effect, as Na⁺ is also contributed by the NaOH aq. sol.

Ok sir !

Thank you and will update you too..

Dear Dr. Shafeek Buhlak ,

I suggest you:

-Advances in Nanotechnology and Its Applications

Ahmad Tariq Jameel and Abu Zahrim Yaser Editors

Publisher: Springer Verlag, Singapore

Publication year: 2020

ISBN 10: 9811547416

EAN: 9789811547416

-Nanotechnology

Paresh Chandra Ray Editor

Publisher: Nova Science Publishers Inc

Publication year: 2018

ISBN 10: 1536138894

EAN: 9781536138894

My best regards, Pierluigi Traverso.

Thanks for the multiple replies.

The probability of pick-off annihilation in positronium (Ps) is primarily due to electron density, as Rüdiger Mitdank has pointed out. It is described by the overlap of the positron and electron wave functions. However, in practical terms, it is not determined by that alone, but is also affected by various environmental factors. In this discussion, I would like to get into these factors.

For example, water and many other liquids expand as their temperature rises. Since expansion decreases the molecular density (electron density), it is assumed that the higher the temperature, the longer the Ps lifetime. However, this assumption is not true. In fact, the lifetime of Ps is shorter in warm water than in cold water.

Similarly, the relationship between Ps lifetime and pH is not easy to estimate. Therefore, we should base our decisions on experimental data.

Most of the basic Ps chemistry was done in the 1960s and 1970s. In those days, the resolution and stability of measuring instruments were not as good as they are today, and the use of computers was limited. Straight lines were drawn with a ruler on hand-drawn one-log graphs. Therefore, the environmental factors that were reported to be "independent" at that time may or may not be due to the lack of measurement accuracy. As the application of positron science to medicine has progressed, motivation to revisit some of the issues has arisen.

I hope somebody will continue to let us know if you have any information on the relationship between pH and the lifetime of Ps. Thank you very much for your time.

Try to reduce pH of the solution. May be it will help.

Kafia Oulmi Thank you for the recommendations.

Thanks, Jukka. I've gone with ethanol to be safe.

Timothy Braun I am using MFiX for several months and I saw a Barracuda VR. But some reasons (like a budget :) ) I couldn't use a Barracuda.

Each software have different pros and cons for MPIC schemes. Firstly, MFiX is open-source and you can change everything that you want (like a user-defined-function). Also, MFiX has some different discretization schemes, solver types, etc.

Btw, Turbulent solvers are different. I'm working on turbulent case and chemical solvers these days. It seems Barracuda is beginner user friendly, but need to time for learning advanced things for MFiX.

Thanks a lot, it was interesting to read it, but it still did not answer my question about OH-. I feel more and more that nobody knows. One option could be that the OH- goes into the tissues but it is silent about it because it is very difficult to measure. I cannot really see any other solution.

If you want to solve your problem as it appears in the image, I recommend using an equation of state for the enthalpy departure.

I also recommend the following articles:

-A computationally effective formulation of the thermodynamic properties of LiBr-H2O solutions from 273 to 500 K over full composition range

- Exergy calculation of lithium bromide-water solution and its application in the exergetic evaluation of absorption refrigeration systems LiBr-H2O

-Thermodynamic Evaluation of LiCl-H2O and LiBr-H2O Absorption Refrigeration Systems Based on a Novel Model and Algorithm

-Mathematical Model of a Lithium-Bromide/Water Absorption Refrigeration System Equipped with an Adiabatic Absorber

Dear Huyen Tran Dang to my knowledge the formation of difluorosilane, SiF₂H₂, cannot be explained by the reaction of SiF₄ with HF. The latter two compounds will react under formation of H₂SiF₆ (see e.g. the link cited below). I think that the formation of SiF₂H₂ can only be explained by the presence of elemental hydrogen, H₂.

https://brainly.in/question/1115388

Hello Mr. Hajipour

"N" refers to a molecular nitrogen presents in a defined concentration of a molecule or ion. You can find it out by multiplying the molecular weight ratios.

In your example if N in the form of nitrate (NO3^-) is 10 mg, then the concentration of nitrate molecule will be 10 mg N*(62 mgNO3/mmolN)/(14 mgN/mmolN), i.e. 44.28 mg NO3^-.

Same concept is valid for any other atoms and molecules.

Regards

In all metabolic processes in nature, electron transfer takes place at the molecular level. Two fundamental atoms in all living entities are oxygen (O) and nitrogen (N). In direct combination, they form NO, which is one of the most crucial biomolecules because it has a free electron ("free radical"). It is part of a universal communication system in biologicals cells.

If we go one level of abstraction higher, we find the amino (NH2) and the carboxyl (COOH) groups. In the carboxyl function, the electrons can migrate from one O to the other via the C atom (mesomerism). Thus, the H atom can easily migrate to the "partner" NH2 - the electrons are "free" and can participate in biological processes.

It is also why phenols, especially polyphenols (green tea EGCG, resveratrol, quercetin), are biologically very active. If both functional groups occur within one molecule, we have one of nature's most essential building blocks, amino acids.

With more atoms and larger molecules, the electron transfer becomes more complicated, but it can explain almost any drug's mechanism of action. It is perhaps interesting to note that electron transfer within biomolecules is sometimes completely different from what we know from the chemical laboratory.

That is why "free radicals" in the body are not generally harmful but vital.

SUMMARY

In summary, it is one of the most important functional groups in nature. That is the reason why it occurs as a functional group in so many drugs.

Attached you will find a link to a paper describing the effect of some functional groups in drugs.

But ICP-OES is a costly instrument and therefore available in a few research laboratories of third world countries.

Hi Simon, I have used many cleavage cocktails and scavangers for peptide cleavage. My opinion: The cocktails aren't that stable, especially the TIPS and thioanisol. Maybe one week is fine if you keep it in the freezer. I would recommend to start with a fresh cocktail each day for best results.

Dear Prof James

thanks for sharing your nice answer

Heating is to be done

I only want to get rid of the trapped gas and bubbles first

Thanks for your answer !

5%Ti 1%B add as a master alloy of Aluminum in wieght ratio 100:1 Kg

I think the main established routes employ biochemical catalysts. I've been working in this area for more than 7 years and I haven't heard of any new developments in solids catalysts for the saccharification of lignocellulosic biomass. Enzymes are very specific and productive towards breaking glycosidic bonds. Enzymatic reactions also require mild reaction conditions such as low temperature and mildly acidic pH.

Nice question

Good question

Dear Sweety Rani, to a very low extent because of the hindrance of two bulky neighborhood benzene rings. Chain stiffness and compactness reflected by high Tg limit (almost excluded) diffusion at ambiant conditions. These are the main reasons behind PES chemical modification. My Regards

لم استطيع التحميل

Mr. Solis,

What you shall synthesis in your home-lab? Something for the market in United States?

Have you decided to compete with Colombian home laboratories; and reagents in Mexico are freely available in stores?

we have ZnO powder, how can i coat on glass or ITO substrate

The experience of the development of science shows that the quality and significance of a scientific discovery and its usefulness or harm for human civilization are inversely dependent on any expectation, be it the expectations of the entire scientific community, and even more so the expectations of a "non-professional" society. For example, it is known that the great Rutherford, who discovered the atomic nucleus, believed that his discovery would have no practical application.

I think you mean to say the amount of emission by pharma sector. There is no study available but pharma industry is one of the major contributor of pollution. Pharma market is 28 per cent smaller yet 13 per cent more polluting than the automotive sector

The answer to this can be very subjective. It is like saying how much of polution comes from airplane pilots. I have no data to support this but let's try common sense: most human waste comes from factories, mining, transport, institutions and households. There has to be a line between processed and unprocessed waste. If your question meant chemists in academia then I would say it is negligible (<<1%). But if you want to highlight it based on potency, that number can increase if you take subcategories of chemicals only produced in lab.

I may need more information to answer your question. However, you may read my paper to get an idea of how molecular motors and switches work.

1. Proton‐Gated Photoisomerization of Amino‐Substituted Dibenzofulvene Rotors

2. Synthesis and Photoisomerization of Substituted Dibenzofulvene Molecular Rotors

We discuss this aspect in detail.

We have used this technique for one drug and confirmed stability for 12 months at 20C but it is impossible to generalise. Stability will have to be established for every individual drug and set of conditions I;m afraid

.

Hi

As for your Expectation, Analytical Chemistry will be the best option.

Chemistry, Biochemistry and Biotechnology all need Analytical Chemistry - tough than other subjects.

Next Organic Chemistry

Study Analytical Chemistry and contact me for better position in US

Best Regards

- Saranya Bharathi

Dear Eric Täuscher here is another interesting paper by the famous henry Gilman entitled "Color Tests for Some Organolithium Compounds"

this depends on which type of ligand used

Dear Gang Zhu

The applications of chemo-mechanical coupling discipline are going on for the time being into two directions that covering by materials research and development activity:

Designing and manufacturing a multifunctional components that characteristics in a variety of applications e.g. artificial organs.

Highlight the mechanism of material degradation and failure case study e.g. high temperature oxidation process.

Now, in the case of high temperature oxidation the mechanical coupling with the oxidation chemical reaction results in stress generation in the oxide scale formed which in turn affects the chemical reaction rate and the diffusion process of the reactants and therefore, the process become a complex chemo-mechanical as the stress is diffusion dependent during the oxidation and the oxide growth is stress induced.

In other hand, the story may be different with the hydrogel coupling behavior as external mechanical load can induce redistribution of ionic concentration, while a chemical stimulus lead to swelling or shrinking of the hydrogel.

So for this multi-field coupling behavior in a medium, there are many approaches that have been proposed by many researchers leading to a bundle of knowledge for the same coupling behavior .Thus, I think that makes the topic appears as foggy to understand by many of the followers.

I hope the above contribution is helpful.

Best regards

Since the emergence of digitalization, we are moving more and more towards “a machine for every process or problem” This is good for achieving efficiency and effectiveness and for large unimaginative technology companies that follow a marketing strategy as ”convenience suppliers”. However, in school pupils should learn fundamentals of processes. In micro chemistry there is basically no difference between traditional chemistry except scale. So, if you can’t see particles you may be able to precipitate, to concentrate, to color, to separate in order to make them visible. Under Corona condition you don’t have to do that in a lab – you could ask kids to do that at home in their kitchen with household equipment.

I am also amazed that in high-school environments pupils are not taught about the most important purification-separation technologies. They grow up without understanding that today we separate any mixture into its individual particles or molecular components. And so, they do not understand that we should not cheat or lie because we can trace any evidence say in biology, forensics, analytical chemistry etc. The excuse of “too expansive” we are currently addressing by creating a low-cost chromatography instrument for schools. (see https://www.chromatographyshop.com/product/scholar-lc-system/ ) We are preparing easy to handle instructions and experiments that are relevant in our time and exciting. The idea is to get the pupils to do the experiments. Environmental education is best done by involving scholars to change the world.

Thanks a lot, dear professor Madhukar Baburao Deshmukh for your nice answer

Dear T.J. Samojedny ,

Indeed, a good point. I see papers like:

Cole, J. C., Smith, M. W., Penn, C. J., Cheary, B. S., & Conaghan, K. J. (2016). Nitrogen, phosphorus, calcium, and magnesium applied individually or as a slow release or controlled release fertilizer increase growth and yield and affect macronutrient and micronutrient concentration and content of field-grown tomato plants. Scientia Horticulturae, 211, 420-430.

https://www.sciencedirect.com/science/article/pii/S0304423816304691

were the ‘formal’ notation is ‘loosely’ used. I think everybody understands that when talking about Mg content in these type of studies is actually Mg2+.

Personally, I would use Mg2+ as much as possible or talk about Mg ions, but I can imagine that in other disciplines other notations are tolerated or simply more costume.

Best regards.

1. C1*V1 = C2*V2

200 mg/ml * V1 = 40 ug/ml * 300 ml, or V1 = 0.06 ml (of ampiciline)

2. If you mean 75 ml is the total volume of final medium, then:

C1 * V1 = 75 ml * C1/50

V1 = 75/50 = 1.5 ml (of bacteria)

I totally agree with you

INNATE Pharma (Marseille, France)

It varies from school district to school district but typically qualified Chemistry, Physics and other sciece teachers are hard to find. When they get somebody they try to keep him/her and if they can't find anyone the teacher and students learn the subject together.

Dear, did you characterized the product? This reaction requires a rigourous anhydrous conditions. May be the solvent is not dry enough. If this is the case, the NCO formed will immediately converts to an amine. My Regards

You can use Soxhlet or Soxtherm to separate oil by solvent extraction process and Hexane/ Methanol/ Acetone as a solvent.