Chemistry - Science topic

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.

Hello,

Teaching of chemistry in Argentina is almost similar to other part of the world.

Thank you

I think the public perception about chemistry and chemicals is negative due to environmental education. Nevertheless, drugs, plastics, textiles, dyes, fertilizers, pesticides etc. are still purchased and used on large scale.

Dear Philipp Selenschik, the best way is to get experimentaly the average MW via viscometry, GPC, or any other available technique at your place. My Regards

Yunus Shukor thank you very much for your help! We will try to find some mechanism to separate plastic from sea life :)

Also check https://blog.v-hr.com/blog/how-autonomous-cleaning-drones-could-save-the-ocean?hs_amp=true

From my long experience of teaching, the researchers who have rich researching CV usually have poor teaching records and vice versa. That is especially true for the universities that haven't a sufficient researching budget. The reason behind that is that researching needs more time at the expense of teaching.

I guess that the hydroxyl-terminated polymer will have a strong bond with the plasma treated PDMS. Because after the treament with oxygen plasma, PDMS surface will be covered by a lot of hydroxyl group.

Specific Gravity is calculated based on the weight of a substance dissolved in particular volume divided by weight of an equal volume of water. You can try this method to calculate the specific gravity of a substance.

The ETL must satisfy specific requirement to function properly:

- The electron concentration must be as high as possible.

- The mobility of electrons must be also as high as possible.

- The energy levels must must match those of perovskite.

The lumolevel of the ETL must be lower than the conduction band of the active layer.

What is the effect of the molecular weight on these parameters must be known to judge which material alternative will be more suitable.

I would propose that you pragmatic on the issue and make planned experiments with the materials to evaluate it. Or you can measure the electronic properties of the material to assess its properness.

Best wishes

Nor Maisurah so what is your question?

regards,

GB

Dear all, there exists various approaches to correlate conductivity to concentration. Please take a look at the following documents. My Regards

Hi;

I worked on Nigella sativa oil, and I isolated the neutral lipids by soxhlet and then by chromatography on silica column. In the most nonpolar fractions, I determined the triglycerides using HPLC-ELSD detector. I haven't published this last part yet. for the extraction steps, please read these articles. I will be at your disposal if you have any questions.

Widad Sobhi

1- Sobhi et al., 2016. PEffect of lipid extracts of Nigella sativa L. seeds on the liver ATP reduction and alpha-glucosidase inhibition.

2. Sobhi et al., 2011. Hepatotoxicity and Langerhans Islets Regenerative Effects of Polar and Neutral Lipids of Nigella sativa L. in Nicotinamide/streptozotocin-Induced Diabetic Rats

Hello, thank you for proposing this question.

I have been working on estimating gas permeation in 'gas diffusion layers' (GDLs) used in PEM fuel cells for power generation. During my course of research I could essentially utilize fundamentals models into working experiments and secure results. However, I would rather specify the challanges here, and would expect the community to help me with some leads.

1. Transport of gas in porous media, can be affected in more than one way, however the concept of Knudsen diffusion (in relation to the nature of gas) needs a far more rigorous interpretation.

2. The influence of relative humidity (Dry gas+vapour) flow in the porous media also needs a strong understanding.

Thanks and regards

Askar Soltani

The term adsorption is used when something is soak (поглащается) by a surface. Surfactant adsorption by activated carbon. If something is soak (поглoщается) by volume, then the term absorption is used. Sound absorption by liquid, gas absorption by liquid.

Dear all, please check these documents. My Regards

Dear all, if you want to get a complete vision on the most important solvents search for 'exfoliation of graphite to produced graphene', a wide possibilities of dispersing solvents are available. Meanwhile, please check the following RG thread. My Regards

Because in chemistry research we dceal with facf and not behavoiu. r s

Look at Crystallography Open Database (COD). It's a free database for crystal structure. You can download the cif files to perform analysis and Rietveld refinement.

Locating a single proton from e density difference maps would be tricky to say the least. Structurally, μ₃-O^2- will be planar, whereas μ₃-OH^- will be pyramidal.

There are physical techniques like magnetometry and EPR that may help you assess the spin of the metal ions if they are magnetic.

Please read my responses again. No opinion(s) are given except that your question does not address the features available in most research grade chromatography software. Curve fits can not be categorized into just two types, linear and quadratic. You make it sound like we must choose only between these two choices. Are you using a software package that limits you to only 2 types of curve fits? If so, that may pose a problem for some sample types. Why do you limit this to just two curve fit types when in fact, several types may be needed for some sample types (e.g. the n-polynomial fits are useful too)? Some real world samples require far more than 2 (proof can be found from experience using many types of specialized detectors and different compounds. The literature is filled with examples, but the easiest way to see examples would be to search for HPLC-ELSD based methods). To ask 'why' instrument vendors include various curve fit options in their software does not address an actual need, but a perceived one. IN the case of curve fits, the DATA determines which fits are appropriate (not the vendor) and we are fortunate that so many chromatography software vendors have continued to include and offer many different types, similar to what is found in good quality statistical software packages.

I never stated that Linear output should always be used. I stated that you should use the best fit, the best formula that describes the data. This is not an opinion, but the mathematical model used to describe a data set.

Regarding calibration of mixtures. This has nothing to do with them all coming in the same vial. It is about measuring the response obtained from EACH sample or standard (which is not related to them being in the same vial. That is concentration, not response). We calibrate and fit points based on response. Two different proteins with the same concentration in solution can have two different responses (e.g. depending on the detector used), and this is why we measure it, record it and then plot it for each compound.

The research knowledge shared during the webinar is much more significant .It also extend your CV and during promotion it will be helpful.

Thanks for your invitation. We can contribute if publication charges are waived.

The chemistry would help respondents

Anything that would have a charge at basic pH, such as phosphate, sulfate, carboxylate, or tetrazole would help with solubility, but these are negative charges, of course. A quaternary ammonium group has a positive charge.

I will get back to you soon.

In the paper, "Heterogeneous photo–Fenton treatment for degradation of indigo carmine dye ". Cosme-Torres, et al., MRS Advances © 2019 Materials Research Society DOI: 10.1557/adv.2019.451 . 23 de febrero 2020. https://www.cambridge.org/core/terms,

you can read about this topics

Dear Lokesh Murali, by in-situ polymerization, you can easily solve MXene and aniline in the same solutions, then mix them by ultrasonication, and next initiate polymerization with dropwise addition of APS. the following paper is the same approach for PANI and clay layers:

Kindly check https://www.jbc.org/content/239/8/2496.full.pdf

Well, if I were you, I wouldn't "mix a chemical reaction", just a reaction mixture. I wouldn't "move a chemical reaction" either. The chemical reaction also cannot be "pushed around by fluid flows" or "flow". Unfortunately, there are more awkward or incorrect phrases in your text. It is clear that you are a physicist and not a chemist.

Dear Jitesh Pandya, please check the attached file and the references therein. My Regards

Recall that the award goes to someone that made a discovery with significant impact. The MRI for medicine, Black Holes for Physics, past organic chemistry discoveries for Chemistry, etc their is now a bit more a blur between physiology/medicine and chemistry. In the past so much was still being discovered in chemistry but now discovery is being made but the award is not for just discovery but for knowledge and impact. So the lines blur for medicine and chemistry. We find discoveries in chemistry that impact medicine and have real world impact. So the cheap answer is that the lines are blurring and utility and impact are becoming felt in society thus making an argument for the justification.

Hello

you will find the answer in the following articles

Previous studies are mostly using default commercial codes for their modelling, perhaps developing your own code for a specific model could be useful for future studies.

Try to use processing in HMDS (hexamethyldisilazane). For photoresists it work well.

Research proposal in Organic chemistry some more topics I want to suggest 1)Microwave assisted synthesis of heterocyclic compounds

2)Extraction of the plant products and their biological activity

Please note that sodium chloride solution with a concentration of 245.3g/L is not to be obtained by dissolving 245.2 grams of sodium chloride into 1 L water. Instaed 245.3g of NaCl should be dissolved in somewhat less water, in a volumetric 1L flask, after that filled up to 1.000 L of solution.

Dear Elecia Henry ,

The journal ”International Journal of Pharmacy and Chemistry” is published by SciencePG (or Science Publishing Group) which is listed in the Beall’s list of potential predatory publishers:

This is an important red flag. Other red flags are:

-In the indexing info no serious indexing in fact for example “Directory of Research Journals Indexing (DRJI)” is an example of a misleading metrics: https://beallslist.net/misleading-metrics/

-Misleading location: ‘office’ is USA is a virtual office (something predatory publisher often use to suggest another location than the real location Pakistan)

-See for numerous examples of predatory features of this publisher: http://flakyj.blogspot.com/2017/01/science-publishing-group-sciencepg.html

So better to avoid.

Best regards.

Dear Alvin Kissoondoyal, if it has such a shielding effect it will help and contribute in sound isolation. The main effect is that of PU bulk structure. My Regards

I will recommend COMSOL Multiphysics . It does take care of chemistry and mechanical properties

Dear Lokesh Murali please see this useful article entitled MXene supported CoxAy (A = OH, P, Se) electrocatalysts for overall water splitting: unveiling the role of anions in intrinsic activity and stability

In the same way of Moosa Faniband, when you add NaCl, to aqueous phase become more polar, changing the partition coefficient. So, the analyte will be push to organic phase, increasing concentration in isooctane.

Hope helps

I think that the teacher can use some applications that are online intended for learning the nomenclature, elaboration and spatial representation of molecules. There are also reaction simulators and laboratory practices where through color change you can explain and discuss with students the causes of a color change or a gas release. Also the teacher and students can make representations through animation programs that are useful to represent (model) some change or transformation of the matter.

Hi Lokesh,

Can I ask more about your goals with this project? You can in principle get almost any conductive material to act as either a cathode or an anode based on the potential you apply to that material, so long as you have a counter electrode to facilitate the closure of the circuit. The question is how good of an anode or cathode your material is, and that will largely depend on what reaction you want to occur within that material or at its surface.

To give a concrete example - and sorry here if I am using a different sign convention (these things can be tricky, but I come from a U.S. Chemical Engineering background): if I apply a cathodic (negative/reductive) potential to a platinum electrode in a conductive aqueous solution, I'll drive a net cathodic/reductive reaction (such as hydrogen evolution). If I apply an anodic (positive/oxidative) potential to that same platinum electrode in that same aqueous solution, I'll drive a net anodic/oxidative reaction (such as oxygen evolution). And if I have two platinum electrodes in the system at the same time, then one can act as a counter to the other; one will drive hydrogen evolution, and the other, oxygen evolution. There is nothing different about the electrodes or the solutions they are in, except the fact that I am controlling the relative potentials of the electrodes through the input of energy into a potentiostat (or similar device). Note: this is an electrolytic example, but I'm happy to discuss things from a galvanic cell perspective if that is more useful.

Best wishes,

Kindle

When I was in high school I did an experiment on 3 different light colours (red, blue and green) and their respective effects on green bean plant growth. You can try this experiment using different light colours or different plants.

Or you can conduct a research on the effects on soil pH on plant growth.

Hi,

For those having a cross-talk problem, it is better to choose the deuterium or carbon isotope dilution method for internal standard (IS) quantitation. If you cant provide the isotope synthesized molecule or co-elution exist and you cant improve the chromatographic resolution then I strongly suggest switching your IS with an analog molecule, which behaves like your target compound (Extraction yield, ionization suppression effects etc.) but also giving fragmentation product at different MW far away from your target fragments.

Thank you so much for pointing out the article, Dear Cüneyt Altındaş.

I see that it is related to a time symmetry breaking state and that there were two possibilities, classical and quantum time crystals.

I will try to understand the idea of the classical time crystal. The authors point out two simple hamiltonians, with broke spatial and inversion symmetry. They find some lagrangians that would be interesting to compare to the lagrangian of isotropic crystals.

Not possible it is in dissolved state. You need to use evaporative crystallizer

In my opinion, no. as far as practical examination is concerned there is need to analyze the student capability in chemistry.

Brilliant, thanks for confirming!

Dear Zahra Nazemi, you can break down aggregates by sonication, but you should first check literature for possible degradation. My Regards

What equation? Do you mean the Michaelis-Menten equation? They can be determined graphically on the basis of the V = f (c_S) curve, or can be calculated using, for example, non-linear regression.

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Hi Luis, metabolomics studies the metabolome in a top-down, experimental manner. The metabolome comprehends the whole ensemble of small molecules, with grey limits within biological oligomers. Proteins, genes, transcripts, are not part of the metabolome, neither lipids or glycans in my opinion. While MS or NMR can/will 'virtually' be able to obtain information about any molecule, for sure it will not be in a high-throughput manner, measuring everything at the same time. In fact, metabolomics is the least high-throughput omic technique where robust bioinformatic pipelines are still under development when compared to proteomics, genomics, etc. Many analytical techniques are 'the true' technique to answer the problem to which the technique is focused to retrieve data valuable to be evaluated.

Endnote

Mendely

Origin

ChemDraw

Docking

Rstudio

Matlab

there are many soft wares, it depends on your work.

Dear Reads Nima Tabatabaei Rezaei,

Have you tried the way I propose to go ahead for the same? Just try it.Somebody has done and successfully got some very interesting synthesis results.

Because of the good thermal stability and superior carrier transport characteristics of formamidinium lead trihalide perovskite HC(NH2)2PbX3 (FAPbX3) has been considered to be a better optoelectronic material than conventional CH3NH3PbX3 (MAPbX3). The FAPbBr3 photodetector’s responsivity to two-photon absorption with an 800-nm excitation source can reach 0.07 A W−1, which is four orders of magnitude higher than that of its MAPbBr3 counterparts. Materials such as Formamidine acetate, lead bromide (PbBr2, > 98%) and hydrobromic acid (48 wt% in water), Gamma-butyrolactone (GBL) and N,N-dimethylformamide (DMF) may required for synthesis.

Formamidinium iodide (FAI) and formamidinium bromide (FABr) can be synthesised by dissolving formamidinium acetate powder in a 2x molar excess of 57%w/w hydroiodic acid (for FAI) or 48%w/w hydrobromic acid (for FABr). FABr can be synthesized by slowly dropping 10 mL hydrobromic acid into 50 mmol (5.205 g) formamidine acetate in a flask, accompanied by continuous stirring at 0 °C for 2 h under argon atmosphere. The product FABr was formed once the solvent was removed using a rotary evaporator at 70 °C. The crude white powder was dissolved in ethanol and subsequently reprecipitated in diethyl ether. Then, the filtered product was dried at 60 °C in a vacuum oven for 24 h for further use.

Ashish

Claire Boyer I think that simply soaking the fibrous mat in a solution of Cu(acac)₂ in dichloromethane over night will be sufficient to impregnate the pores of the MOF with the copper precursor. As suggested earlier, use dichloromethane instead of chloroform to dissolve you Cu(acac)₂.

P.S. When other RG members help you by answering your questions, it is polite and a good practice on RG to recommend their answers.... 😎

Dear Michael Pujari-Palmer, why don't you use directly AFM for contact measurement? My Regards

Hi Alida, this is a really good question. I think that the basis for this is the combination of basic and acidic dyes to stain acidic/basophilic, and basic/acidophilic molecules in tissue, respectively. I realize that your question is really asking why some stains won't work without their counterpart. I know that you must use basic dyes before acidic dyes, and alcohol before aqueous, otherwise staining will not work. I suggest Animal tissue techniques (A Series of books in biology) 3rd ed. by Gretchen L Humason. It was published in 1972, but is still one of the best histology books I've ever seen. You can get it on amazon for about $10, ISBN-10: 9780716706922 .

Hameem Habib You need to have a centrifuge machine. The machine which I had access to, can go up to 12000 RPMs. However, I centrifuged my material at 8000 RPMs. Something over 3000 RPMs can also work (with problems). But, I recommend 8000 to 10000 RPMs. Steps are as below:

1) Arrange centrifuge tubes.

2) Fill centrifuge tubes with your GO liquid mixture upto two-third. For example, if your centrifuge tubes have a capacity of 10 ml. fill them upto 6ml. All tubes must be filled with the same volume of mixture.

3) Now put centrifuge tubes in the centrifuge machine. Remember to place them in such a way that there is gap of one slot between any two tubes. Which means if machine has 6 slots for tubes, only three must be occupied by the tubes. This is to maintain equilibrium of load for the wheel when it spins.

4) Centrifuge the tubes for 15 minutes at 8000 RPMs.

5) Take out the tubes. You'll see brownish substance sticked at the bottom of the tube.

5) Take out the tubes. You'll see brownish substance stuck at the bottom of the tube.

6) drain the liquid at the top of the substance. Don't worry, substance will not fall off.

7) Now add remaining GO mixture in tubes and centrifuge again with same RPMs and time.

8) Repeat this process until all of your GO liquid is finished.

9) Now add De-Ionized (DI) water in the tubes. And remember to fill the tubes upto two-third.

10) Now shake all the tubes by hand (closing them with their caps) so that the GO substance settled at bottom gets mixed with the water thoroughly to form a mixture.

11) Again place tubes in the machine (remember to place them with the same gap) and centrifuge them.

12) After centrifuging drain the liquid at the top of the substance.

** This step will reduce the Ph of the mixture by reducing the HCL present in it**

13) Repeat step 12 until you achieve a neutral Ph (Ph of 8 would also work but please do some hardwork to achieve 7, I know it would require a lot of labour).

14) You can check the Ph of the liquid in the tube before draining it through a Ph paper or with the help of a Ph meter.

15) After a neutral Ph is achieved, use something clean to take out the GO from centrifuge tubes carefully.

Hope it helps. If you

That is the weakness of lumping: The mass balance of components requires information on the product composition, which is not accessible after lumping. One might use average values for the products, such as molar mass or density. Those average values, however, depend on the composition, which is not known after lumping. The mass balance consequently contains errors. Therefore it is probably more meaningful to go for molar balances assuming constant density or flow rate (note that appropriate assumptions depend on the specific problem).

In general the applicability of lumping always depends on the accuracy required, which is defined in the problem statement. Therefore it has to be clear, which kind of assumptions are appropriate (e.g. constant density, flow rate, etc.). Furthermore, none of the products should affect the kinetics of the involved reactions.

Please also keep in mind that your question is rather generic and can't be answered in general, as the answer always depends on the specific problem.

Please go to this link:

There must be some problem with the pH meter then.. U should show it to a technician so that it can be fixed.

Can have a look - on the attached manuscripts

Please check the following link, I hope this can help:

I highly agree with the opinion reported by Frank T. Edelmann

Regards