Science topics: Chemistry
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Chemistry - Science topic

Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds.
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Here is the completed list of Impact Factor for 2022.
Journal Citation Reports 2022
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This is fast
Even the scientist in the Netherlands publishing this on a website did not have it yet!
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We are testing new chemicals for redox flow batteries. We consistently see this weird potential "x" with galvanostatic bulk electrolysis cycling experiments in an H cell, has anyone had this issue before? We have this same issue with the novel anolyte/catholyte chemicals we are testing, so we ran a bulk electrolysis experiment with Fc/Fc+ symmetric cell to see if the issue persisted (both with membrane and with fritted H cells). I see this potential crossover all the time with 100% and 80% SOC experiments, I'm going to test 50% SOC to see if the crossover remains. The reference electrode seems fine based on CV experiments, the reference electrode issues are the only thing I can think of. Isn't it theoretically impossible for the oxidation to start at a more negative potential than the reduction? I see some solvent loss over the period of the experiment. This is the first redox cycle and the crossover is consistent throughout the experiment.
Symmetric h-cell setup
0.001 M Analyte (Fc/FcPF6)
0.1M TBAPF6 in MeCN
10 mL Volume on each side
AMI-7001 selective membrane
BASI nonaqueous coralpor fritted reference electrode (0.01M AgNO3 in 0.1M TBAPF6 in MeCN)
0.27 mA for 1 h (100% SOC)
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Simon Gersib Hi, the resistance of the glass frit ion flows is surely an issue. Have you measured the ac impedance of your cell in the background electrolyte? With your current being 0.27 mA, it means that a resistance of 350 ohm in the glass frit will produce roughly 100 mV voltage drop (iR drop) which is high enough to cause the crossover.
However, I shall point out that in the bridge section of your H-cell, stirring is almost no effect.
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I want to prepare 2% solution of chitosan using 0.5 M acetic acid but need to adjust pH to 4. How can I do that? I added NaOH to the chitosan solution, precipitates were formed in chitosan solution.
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I think you should add the conjugate base (CH3COONa) but not NaOH
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Forgive some of my ignorance in the math for thermodynamics and heat exchange but my background is heavier in Chemistry and could use some help.
The project is to keep about 70L of water in an aquarium at 17C when the ambient temperature is 22C in the room. The original project built had the following set up:
(Top to Bottom):
1. 80x80x38mm fan running at 5700 RPMs and 76CFM
2. 80x80x20mm copper fin heatsink (0.5mm fin thickness and 40 fins with a 3.5mm bottom thickness)
3. 2-TEC1-12706 hot side towards heatsink, cold side down towards water block (Imax: 6.4A, Umax: 15.4V, Qmax: (dT=0) 63W, dTmax=68C)
4. 40x80x12mm water block centered under the heatsink (surrounded on the sides with 20mm styrofoam and 10mm styrofoam at the back)
5. ~26mm thick styrofoam
6. Wood base
• All power is supplied by an AC/DC converter (12V 20A 240W)
• Power to the system is managed by a W1209 Temperature Control Module (Relay)
• Water flow is achieved by a 4L/min water pump (slowest I can find)
This set up is only cooling the water to 18C at night and will slowly creep up to 18.7 across the day so I know this set up is not keeping up with the heat load. (also worth noting that output temp is about 1.5-2C cooler than input temp to the waterblock). My hypothesis is that the water does not have enough time in the water block for good thermal exchange or that the cooler is not creating enough of a dT in the water block to absorb the amount of heat needed to in that cycle time. The fact that the Aluminum water block has a 5x lower specific heat than water is what is making me think either more contact time or great dT is needed.
My thoughts were to swap out the water block for an 40x200x12mm water block and increase the number of peltier coolers from 2->5 and going with the TEC1-12715 (Imax: 15.6A, Umax: 15.4V, Qmax: (dT=0) 150W, dTmax=68C).
This is where is am lost in the weeds and need help. I am lacking in the intellectual horsepower for this. Will using the 5 in parallel do the trick and not max out the converter? OR Will using 5 in series still produce the needed cooling effect with the lower dT associated with the lower amperage? Or is there another setup someone can recommend? I am open to feedback and direction, thank you in advance.
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Have you considered evaporative cooling for your aquarium. As long as the relative humidity in the room is not pushing 100%, you can achieve cooling using this technique. This link will show your how it is done:
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I have a chemical I dissolve in DMSO. But if I put it in the centrifuge and spin it, all the chemical 'bits' will drop out of its dissolved state and form pellet on side of eppendorf.
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Your suspect compound is one with mid-high molecular weight that must be of organic nature. Centrifugating over 5000 rpm will "pelletize" this kind of compounds. Assuming you're working with inorganic or low-molecular compounds it would be a contamination: of your reagents, the DMSO itself or both.
In my experience DMSO is prone to contaminate due his highly miscibility with organic compounds, even some bacterial spores could survive on 99% DMSO. I recommend you to centrifugal your DMSO alone to see if pellets form. If that happens, try using a switch to another batch of reagent, or change to another supplier. You can also try to filter your DMSO with a 0,22 um filter, but I suspect it won't help.
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Hey, I have been looking for it a lot. Are there sigma + - constants for meta substitution?
And also I couldn't find the sigma * constants.
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Yumiao Ma Thanks for your reply.
I am looking for sigma *(Taft), sigma - and + with meta and para substitutes.
And I think that in this article there are only Hammett constants? (Benzoic acid).
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In AlSi alloy, what will be the difference in the chemistry and mechanical properties if Mg metal is added instead of AlMg alloy? Is it advantageous to add AlMg alloy over pure Mg metal? And why?
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Also Al3Mg2 phase will not achieve if we add Mg metal directly into the AlSi alloy, and Mg may react with other alloying elements which might not be accepted for the final alloy
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ethanol can change chemistry of biochar. what possible changes could occur in biochar by washing with ethanol.
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The washing with ethanol helps to a deep removal of organic matter. Depending on the further use of it, it could be beneficial.
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Hello all,
I am preparing a compilation file for doing MESMER calculations but I am having an issue. I am running some g08 calculations with acetyl and it seems like the transition state from for going to the RO2 to QOOH is unstable as the difference between the target energy and the calculated energy differs by about 0.1 - 1.1. There is too big a difference in the energy barriers between the RO2 and QOOH, but all other energies for the stationary points in the channels are comparative to the expected value. The IRC from the obtained transition state gave a significantly high "jump" in the potential energy graph. Would anyone happen to know what is going on?
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By unstable, I mean that the SCF Done is coming out too low than the expected. The target energy is coming from a the Ethanal+OH/O2 system that has been studied in literature that we are trying to emulate. The unit of measurement is in Hartrees
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We are planning to extract phosphorus from biochar by organic acids. If anyone has some procedure (concentration of organic acids & steps) please inform.
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The common method for phosphorus solubilization efficiency measurement of soil microbes is zone formation in agar media (generally Pikovskaya media) but this is a qualitative study. However, there is also a liquid culture method with insoluble phosphorus in liquid media. The estimation of available phosphorus by ICP-OES is quite promising and precise.
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Based on the following study it has been concluded that Phosphorus measurements by HP-ICP-OES showed accurate results with very small uncertainties (0.1%) can be obtained with ICP-OES on digested DNA as has been seen with single-element solutions also, it is suitable for any size of nucleic acid from nucleotides to genomic DNA.
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Hello Community,
I am currently restarting my work on battery management systems, I plan to use Lithium Iron Phosphate cells for their better energy density and relatively better resistance to thermal behaviour than few other commonly sought after battery chemistries. I require some help with good materials or references to help me accomplish BMS for 2W EV. I see that there are Kalman filter based estimations available, but they seem complex and expensive in terms of computations such algorithms require to be implemented.
Kindly request the experienced fraternity to guide me to understand and implement SOX estimation for LiFePO4 Cells.
Thanks in advance.
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Hello,
Firstly I would like to give a small correction: the energy density of LFP is lower than other lithium ion batteries. This is mainly due to the lower voltage produced by this anode-cathode pair. I have made my master thesis on this subject 5 years ago so I will give you some information based on what I still remember (keep in mind that some of my references may be a bit outdated).
On the state of charge (SoC) discussion: the major difficulty with LFP is that its voltage-SoC curve is very flat over a large part of its capacity. This means that the open-circuit voltage does not change strongly as the cell is being charged-discharged. Only at the tails of the capacity (generally about < 20% SoC and > 80% SoC) will the voltage change strongly for a change in Coulombs (which can be expressed as the differential voltage, or dV/dQ). A comparison of estimation methods can be found at (Wladislaw Waag, Christian Fleischer, and Dirk Uwe Sauer. Critical review of the methods for monitoring of lithium-ion batteries in electric and hybrid vehicles. Journal of Power Sources) and another good reference is (Wen-Yeau Chang. The state of charge estimating methods for battery: A review. ISRN Applied Mathematics, 2013)
To make a simple but decent estimation of the SoC of an LFP battery, I'd propose you need 1 main piece of battery/cell-related information and one optional piece of information: mainly the voltage-SoC curve at sufficiently high resolution (which can be transformed to a dV/dQ-SoC curve) and additionally a mapping of the internal resistance of the battery over a range of temperatures & SoC. With this information, you can use a current counting algorithm which simply integrates the current (dis)charged by the battery and uses this to determine the SoC. The issue with current counting is that any measurement error is also integrated and over time this results in a large error. There are some simple fixes for this, at least if your use case allows for it. The idea is to reset the counter and SoC at specific moments: the most useful moment is to reset it when the battery is full, is empty, and/or when it is at rest. If the battery is at rest in the "flat" part of its profile you could also reset the counter, assuming your voltage measurement is sufficiently accurate. If at rest for a very high (or low) SoC, reseting becomes more accurate. If there are not many "rest moments" then it becomes more tricky, but you could use the internal resistance map to estimate the OVC of the battery while it is under load (you could even implement a higher order equivalent circuit model of a battery for a better estimation).
You could also use a simple recursive least squares method to estimate the SoC which has been widely documented in the literature (one example is here: Hongwen He, Xiaowei Zhang, Rui Xiong, Yongli Xu, and Hongqiang Guo. Online
model-based estimation of state-of-charge and open-circuit voltage of lithium-ion
batteries in electric vehicles. Energy, 39(1):310 – 318, 2012. Sustainable Energy
and Environmental Protection 2010)
Good luck!
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Dear science community!
I need your help, please!
I`m totally disapointed and at a loss!
In 2020 (at the end of October) there were the IOP Conference Series: Materials Science and Engineering (ICoSiET 2020). Me and my colegues took part in these conference. As the result (like a result of any other conference) the thesis collection should have been published (at the 4th quarter of the 2020)). Unfortanately, these collection still haven`t publised (despite the fact that 2021 is already at its end).
So, I wonder, if there are anybody, who know something about this situation? Maby there are any of those who also waiting for their thesis?
We have wrote lots of messages to the organizators and the head of the university (in which this conference took place) but they stoped to respond us.
I think this situation shows disrespect for the conference participants. And I believe that such situations should be inlighted in our community!
Thank you, for your attention!
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Using the link as indicated by Shoffan Saifullah , the good news is now that your paper is finally published https://iopscience.iop.org/article/10.1088/1757-899X/1212/1/012013 The thing is that “IOP Conference Series: Materials Science and Engineering” is ' suffering' from their own success and are recently even discontinued (see enclosed file) in Scopus.
The reason is most likely the enormous increase in number of accepted and published papers over the last few years which can be seen by clicking on “Scopus content coverage” here https://www.scopus.com/sourceid/19700200831
I think that the people behind IOP now try to ‘spread’ the papers over more than one year so that the number of papers published annually goes down again towards more acceptable/realistic numbers (at least in terms of inclusion criteria for Scopus).
So, at the very best this is a desperate attempt of the publisher to correct their suspicious behavior (by publishing too many papers in a year which raises questions on how to maintain scientific standards/quality control). This victimize researchers like you who learn the hard way how a publisher is trying to get their act together (again).
Best regards.
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We are doing a fab process involving a patterned titania layer sitting on quartz. We now want to etch a few microns of the quartz underneath the titania, in order to "release" the slab. What could be a could wet etching chemistry to etch quartz without etching (too much) titania?
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In principle silica is more sensitive to hot concentrated base than titania. However, a "quartz" substrate, whether silica glass or real crystalline quartz, is dense and etches very slowly, while your titania is probably deposited from the gas/plasma phase and not very dense. Selectivity may go the "wrong" way.
HF-based solutions will also attack both silica and titania, as you know. You may be able to find conditions of concentration and pH where silica will etch faster than titania, but to etch away the substrate while keeping the (presumably much thinner) deposited film is asking much.
One option I would consider is to interpose a thin Ti metal between the silica and the titania. Ti metal etches very fast in HF, even dilute HF, so you may be able to lift off the titania film without much damage. However, if the titania requires high-temperature annealing it is possible that the Ti will react with the titania to form TiO2-x.
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Heterogeneous catalysts (CaO, MgO, ZnO) have been shown to be less effective in low methanol and oil mole ratios. So, what is the best mole ratio for a heterogeneous catalyst in transesterification?
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For CaO catalyst the best methanol/oil ratio is 12 (molar ratio).
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Can you please suggest some *primary amine protecting group* which one do not chemically disturb by *nBuLi* reagent.
I already tried with PMBCl and Boc
In *PMBCl*, it facilitate ortho direction by itself only.
In the case of *Boc* it doesn't stable, hence it cleave during the reaction and enhance the formation of unwanted side reaction.
I'm studying the chemistry of below listed protecting compound
1) TBDMS
2) Trimethylsilyl chloride
3) MEM
4) MOM
Please give your suggestion which one is compatible protecting group for primary amine in presence of nBuLi reagent.
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The only N protection that is stable enough to allow typical n-BuLi chemistry of which I am aware is to attach two benzyl groups to a primary amine nitrogen, one benzyl group to a secondary amine nitrogen. Removal is by hydrogenation in the presence of one equivalent of HCl added to an ethanolic solution 0.2 M in your benzyl-protected amine derivative, where the HCl is added in the form of 1 M aqueous HCl (the ethanol can be 100% anhydrous or 95% ethanol). The typical catalyst for this is 10% Pd/C. The typical reducing agent is H2 at 60 psi. Typical times for complete removal vary depending on steric crowding around the amine group. PMB (para-methoxybenzyl) is easier to remove by both hydrogenation and by treatment with various acids.
A more thorough discussion is available if you have access to Green's book of protecting groups (Online ISBN: 9780470053485). More rugged groups each have their own problems. For example, a primary amine treated with succinaldehyde [HC(=O)CH2CH2C(=O)H] gives a pyrrole that can be cleaved back to an amine under various conditions. Converting the amine to a succinimide followed by TMSCl and a base gives an easier to remove 2,5-bis(trimethylsilyloxy)pyrrole. 1,2-bis(chlorodimethylsilyl)ethane and base protects the amine as 5-membered ring stable to base but labile to acid and TBAF.
You can mask the amine group as some other group; phenylselenyl chloride makes a phenylselenylamine; similarly phenylsulfenyl chloride makes a phenylsulfenylamine. These can be removed by mercuration or H2/Raney nickel. You can react the amine with an electron-deficient aryl chloride, displacing chloride and generating an electron-deficient aniline derivative that may lose one proton but not react further. Picryl chloride and chloropentafluorobenzene can react with amines to give anilines, and there are probably cutting-edge protecting groups based on these.
I would recommend against using MOM and MEM groups because under basic conditions these might result in a more reactive imine forming that can react with n-BuLi. These protecting groups are not suited to amines. They work well with alcohol protection, where the products are acetals of formaldehyde. If you are interested in that kind of group, think about exploring turning your primary amine into a derivative of thiamorpholine [a two-step but very clean reaction sequence avoiding the use of bis(2-chloroethyl)sulfide is treatment with 2,2'-thiodiacetic acid using a coupling reagent strong enough to form the cyclic imide, followed by reduction by borane-dimethylsulfide to the thiamorpholine group]. Removal can be the same as removing other sulfur-based groups (H2/Raney nickel, which leaves behind a diethylamino group) or oxidation (by MCPBA/bicarbonate or H2O2 etc.) in acetonitrile followed by aqueous base like 5%-10% potassium carbonate (the end product is the primary amine and 2,2'-sulfonyldiethanol, a water-soluble diol byproduct). I did the latter and it is a high-yielding, very mild protection and deprotection in which BOC-protecting group, acetals, esters, nitro groups, and conjugated C=C-C=O survive, but isolated C=C groups, carboxylic acid, aldehyde and ketones don't. I don't recall the literature references I used, off-hand, sorry. I would need access to a literature searching tool better than Google Scholar, but I don't have that. However, it's an example of "seek and you will find" that worked for my particular synthesis of a differentially protected non-natural amino acid, 2,4-diaminobutanoic acid, sometime around the late 1990's. So keep seeking. Best wishes.
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I am looking for a topic to start my research in chemistry. something which is untouched so far or where research gap persists. A topic which has national and international importance. Completed my coursework so far.
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You're welcome Roma. All the best.
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I have synthesized the metal nanoparticles and I want to know that the size of magnets used for stirring purpose has any effect on size of nanoparticles so does the speed of stirring.
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Dear all, the size of the stirring bar influence essentially two factors, i.e., shear degree or level and heat conduction and dissipation. These two factors are in direct influence on all NPs features : growth kinetics, shape, size and its distribution. The effect may not be monotonically scaled, but for sure it is a compromise between these factors. My Regards
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I am using commercially available vitamin A mix for a project. It comes in capsules and is very dense so I thought to dilute it with soybean oil.
The vitamin A solution has an approximate density of 0.8523 g/mL (I calculated this by filling 0.3 ml of the VA solution in a microtube and then weight it [minus the tube weight of course] and it was 255.7mg). Then I added 0.3ml of soybean to the microtube and mixed them. This allows me to easily use a micropipette but now I don't know how much vitamin A solution I'm taking each time (in 20ul of the solution for example).
I need this because I add the carotenoids to a feed and I need to know how many mg I'm adding.
This might have a very simple solution but the fact that is the oil is throwing me off. Thank you in advance.
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Hi David ,
You may use the web tool to calculate
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Collected the FTIR spectra of an unknown polymer sample and tried to match with my database.
But it is not matching with any entry of my database. Indeed quite different from the existing entries. So please help me out in identifying its chemistry and how can I do it in future?
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Kamran Nasir Yes, you are right, as long as you compare it to other spectra that are recorded under the same conditions (same angle of incidence, ATR crystal and polarization state) there should be no problem.
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Dear experts
The study of metal pollution in continental rivers is it still a current topic and a primary research focus? What are the new research axes for environmental chemistry?
Thank you
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Heavy metal pollution will always be relevant. However, I think that further studies on remediation strategies will be a plus.
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respected all,
i'm looking for reacting gaseous reactant with a liquid reactant, resulting product is gaseous, please tell me how to do such reaction and collect product with accuracy.
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Adding to Dr. Hanson's setup, if you want the gaseous product to be free (or mostly free) of reactant gas, you can connect multiple gas dispersion tube in parallel so that all the reactant gas is converted to product. Reactant gas to inlet of gas dispersion tube containing liquid reagent, outlet connected to the inlet of 2nd gas dispersion tube containing more liquid reagent, outlet of the 2nd gas dispersion tube connected to the inlet of 3rd, if required, and so on.. You can collect the product gas from the last outlet.
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If you have a substance of density x g/mol with boiling point y and one with density z and boiling point a and we make a 90% mix of 1 and 2, what is the resulting density and boiling point?
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In principle it is an easy calculation but in practice it depends heavily on the substances and their interaction.
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As well known
In almost all papers the experimental section is so short and not detailed for instance no clear weights setup and so on
Where can we find expanded detailed narration of experiments and methods
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The same concerns will be shared here which means I agree. The supposed standard concept of ethical publishing and research were taught and still in practice. Direct communication to the author/ correspondent is necessary, and in this way, limited access or limited amount of the manuscript maybe shared, both parties protected, and continuum of knowledge is not compromise. Best wishes.@Mahamid
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I have tried to cure the CNSL resin with a Hot air oven of 180 degrees Celsius. Still, I am not getting the proper solidification of the resin, the specimen which is kept in a Hot air oven is in a spongy state. I want to know the process/ steps/ procedure for curing the CNSL resin?
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Cashew Nut Shell Liquid - an overview | ScienceDirect Topics
https://www.sciencedirect.com › topics › engineering › ca...
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Hi! I have two small molecule structures, and I need to create a model of them connected by a bond. I have found plenty of software where I can upload one, and then add or subtract atoms one at a time (PubChem Sketcher, Avogadro, there are tons available as web tools or downloadable software) but I have yet to find one where I can upload two molecules and then... combine them. This seems like such a simple task but I've run out of ideas! I would love any suggestions. If you cannot think of any free tools, suggestions for paid software is also welcome.
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I have figured it out and it's a little less tedious than Christina Ertural's excellent answer. I took the simpler of the two molecules, converted it to SMILES, and then did Build > Insert > SMILES in Avogadro. If I ever need to conserve the coordinates, I'll use the Excel trick. Thanks!
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In biodiesel production through transesterification, various of heterogeneous catalysts could be utilized. However, each heterogeneous catalysts are showed different yield. My question is What are the factors of heterogeneous catalyst that affect their activation during transesterification?
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Hello Viraj,
thank you for posting this very interesting technical question on RG. We work in the field of synthetic inorganic chemistry, so that I would not call myself a proven expert in the field of heterogeneous catalysis and transesterification. However, I can suggest to you two very instructive review articles which will certainly help you in your analysis. Thus please have a look at the following references:
Heterogeneous catalysis for sustainable biodiesel production via esterification and transesterification
Fortunately this paper has been posted by the authors as public full text on RG, so that you can freely download it as pdf file.
The other paper can also be accessed as public full text as it has been published Open Access:
Application of Heterogeneous Catalysts for Biodiesel Production from Microalgal Oil—A Review
(Please see the attached pdf file)
I hope this helps. Good luck with your work!
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What is the chemistry behind chloropicrin used as a pesticide, as it available in three different formulation registered in Pakistan e.g. in one registered product it act as an active ingredient, in 2nd it as an inert ingredient while in third one it act as a warning agent.
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Over the last few months, I have come across several posts on social media where scientists/researchers even Universities are flaunting their ranking as per AD Scientific Index https://www.adscientificindex.com/.
When I clicked on the website, I was surprised to discover that they are charging a fee (~24-30 USD) to add the information of an individual researcher.
So I started wondering if it's another scam of ‘predatory’ rankings.
What's your opinion in this regard?
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I need to find a proper method to prepare sample solution by digestion for Pt-Pd-Rh elements from spent automotive catalysts. Any suggestion except application of microwave-assisted digestion would help me.
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Dear colleague,
I am sending the following decomposition procedure which we used in the analysis of catalyst samples [1]:
1 g of the catalyst samples was weighed in a 50 ml beaker. 15 ml of
freshly prepared mixture of acids (5 ml conc. HNO3+15 ml conc. HCl)
was added to the sample and the beaker was covered with a watch
glass. The sample was left to stand for 1 h at room temperature in
order to prevent vigorous reactions. After that, the sample was heated
for 6 h on a water bath and allowed to cool down slowly to room
temperature. The content of the beaker was transferred quantitatively
into a 100 ml volumetric flask and filled up to the mark with redistillated
water. The undissolved material (γ-alumina+silicates)
has settled down and the supernatant solution was subjected to
analysis by ICP-AES. The volume of the solid residue is less than 0.4% of
the final volume.
Please, see Ref.[1]
REFERENCES
[1] P. Petrova, S. Velichkov, N. Velitchkova, I. Havezov, N. Daskalova “Problems, possibilities and limitations of inductively coupled plasma atomic emission spectrometry in the determination of platinum, palladium and rhodium in samples with different matrix composition”, Spectrochimica Acta Part B 65 (2010) 130–136, doi:10.1016/j.sab.2009.12.005
With kind regards, N.Daskalova
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I have purified crude glycerol which is come from as a byproduct of transesterification. I need to know, the purity of the sample after purification. What methods can I apply to get the glycerol purity?
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The following useful RG link is also very useful:
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I'm working on metal-organic coordination complexes, I got a wavy and large NMR shifts for some of complexes which I anticipated as paramagnetic.
Can you explain the relation between paramagnetic nature and large shifting in NMR ?
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Dear Manel Taferguennit in this context, please have a look at the following instructive presentation:
Paramagnetic NMR
The presentation is freely available on the internet. It might also be worth reading the answers given to the following closely related question which has been asked earlier on RG:
Why do unpaired electrons make NMR measurements difficult?
(6 answers)
Good luck with your work!
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As a byproduct I obtatin glycerol from transesterification reaction. I currently expecting to developed a handsanitizer from crude glycerol. My question is how I can develope a handsanitizer from crude glycerol?
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Kindly see also the following useful link: https://www.wired.com/story/how-to-make-hand-sanitizer/
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I am engaged in purifiying crude glycerol made from biodiesel. As a first step, acidification was carried out with phosphoric acid, however, K3PO4 percipitate must contain inorganic salts. But, in my case, I did not see any salt after the pH of the medium dropped to 1. What is the reason?
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Dear Viraj,
many thanks for sharing this very interesting technical question with the RG community. Did you follow a published procedure? Perhaps I did not fully understand your question. However, after the acidification step, you don't have any potassium present in your mixture. Thus at this stage no K3PO4 precipitate can form. This can only form after separation of the different phases and neutralizing the purified glycerol with KOH. Please have a look at the following published procedure (citation):
"As the crude glycerol received is solid at room temperature, around 200 g of the crude glycerol was melted at 55 °C in a 500 ml beaker placed on a magnetic hot plate. The molten crude glycerol under gentle stirring was acidified with different acids (sulfuric acid, hydrochloric acid, and phosphoric acid, respectively) to a desired pH level and was kept for a sufficiently long time to allow the formation of three separate layers. The top layer is fatty acid phase, the middle one is glycerol rich phase and the bottom one is inorganic slat phase. The bottom phase was separated by simple decantation. The fatty acid-rich top phase was separated from the glycerol-rich phase by using a separator funnel. The extracted glycerol was neutralized using 12 M KOH solution followed by evaporation of water at 110 °C for 2 h and filtration to remove the precipitated salt."
As you can see, you need to separate the phases, neutralize with KOH, and then remove the remaining water by evaporation. Only after these steps have been carried out, the potassium phosphate salt will precipitate.
This is the article from which the cited procedure was taken:
I hope this helps. Good luck with your work!
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Glycerol is the primary by product of the transesterification reaction which is in the biodiesel production. However, this crude glycerol have contaminated with various of compounds ( monoglyceride, diglyceride, triglyceride, salts, FFA..etc). My question is, what are the possible value added produt that can be produced ny crude glycerol whithout a purification?
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It depends on the type of crude oil you are using and the type of other reactants
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I am currently working with an experiment producing biodiesel from a heterogeneous catalyst. After the reaction I have to recover the catalyst after the reaction is over. I hope to use the centrifugal method to bind the catalyst to the surface of the centrifugal tube as a Pellet. However, I can not take the bound catalyst superficially.
How i can recovered this heterogeneous catalyst?
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After the last reaction analysis is complete. Dilute it with methanol and wash it, centrifuge again, the catalyst will be better recovered.
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I'm currently working on my chemistry research proposal, focusing on the synthesis of ZSM-5 from natural resources (Kaolin and Clinoptilolite). However, I'm struggling to gather the needed reagents such as the SDA. Common SDAs used in published literature and studies are Tetrapropylammonium bromide and Tetraethyl orthosilicate, but these are expensive and hard to find. Can you suggest any alternatives for these? Thank you in advance.
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Dear Jhune Dominique Peralta Galang thank you for sharing this very interesting chemical question with the RG community. I'm not really a specialist in this chemistry. However, I can suggest to you the following potentially useful review article which might help you in your analysis:
Zeolite synthesis from low-cost materials and environmental applications: A review
Fortunately this article has been posted by the authors as public full text on RG. Thus you can freely download it as pdf file. Moreover, most of the authors of this paper have RG profiles. You can easily contact the corresponding author via RG and discuss your question directly with him as he is a proven expert in the field.
I hope this helps. Good luck with your work and best wishes, Frank Edelmann
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I am just creating here a space for the discussions about the recent groundbreaking advancements in the synthetic organic chemistry and hence anybody can discuss about very recent and interesting inversions in organic chemistry including novel methods.
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Interesting topic. I think these documents (in attached) may actually interest you since the book summarizes the groundbreaking advancements in organic chemistry made during the19th century while the review article those of twenty-first century.
Best wishes,
Sabri
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In transesterification some of heterogeneous catalyst such as BaO, SrO, MgO, and CaO shows different biodiesel yields. In general, BaO and SrO show high activity than MgO and CaO. My question is how these compounds do have different catalytic activity?
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Dear Viraj Miyuranga . See the following useful link: http://www.bioline.org.br/pdf?st11020
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Several studies on combustion of bio diesel/petroleum fuel blends in IC engines and other power generation / combustion devices discussed extensively about the influence of fuel unsaturation on NOx emissions. A fundamental question arises on how we quantify fuel unsaturation?
I would like to start a discussion on the topic - How to quantify fuel unsaturation ? what would be an appropriate index to quantify unsaturation irrespective of the family of origin of fuels - like methyl esters, ether, alcohol , alkanes, alkenes, alkynes or aromatics or a weighted combination of aforementioned categories.
Our research group's take on this -
We have established a parameter - Degree of unsaturation that serves as a common platform across different fuel families (esters/alkanes/aromatics) to quantify the effects of fuel unsaturation, particularly with petroleum/bio-diesel blends. DOU can be evaluated based on the average molecular formula of the fuel alone without involving complex and expensive experimental procedures such as those involved in the measurement of iodine number and bromine number.
If interested, please follow the link to access the research work we have conducted at our laboratory to investigate the effect of fuel unsaturation on nitric oxide emissions.
Message me to get a copy of this article.
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SNAP
How to use SNAP as a nitric oxide donor correctly? Is it possible to prepare a stock solution and store it in a freezer, and prepare the working concentration by dilution before application?
Or should SNAP crystals be dissolved immediately before use?
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The reagent SNAP, are prepared by mixing solutions of N-acetyl-penicillamine, with equimolar NaNO2 in 0.5 N HCl. The reaction is typically complete within 1 min; for reasons of stability, the solution is neutralized by addition of NaOH immediately before addition to the protein solution. source: Nitric Oxide Synthase: Characterization and Functional Analysis
Ying-Yi Zhang, Joseph Loscalzo,
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As I have read a paper on Vlab for molecular symmetry, I want to know where else this can be used?
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See attached article
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Occasionally when handling wetted picric acid or saturated solutions some solution can be transferred to gloves or a very small spillage (a few drops) might need wiping up with a tissue. I then dispose of these gloves and tissues in the bin where they can dry out. How dangerous are these dry residues in terms of explosion? What is the best practice in this case? Thanks.
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contact with even a small amount can cause an allergic reaction with symptoms such as skin redness, itching, rash and swelling.
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Does anyone has an experience with sodium tert-butoxide? How dangerous it actually is?
Do I need to use a glovebox while weighting and handling it?
Do I have to dissolve it in THF at -30C or room temperature will also do?
How do you store it after the can is opened?
We have 100g of sodium tert-butoxide in total, the planned amount for my synthesis is ca. 1.5 g.
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Precautions for safe handling
Do not breathe dust/fume/gas/mist/vapours/spray.
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In the Lupine industry when lupin beans are detoxificated, lupanine goes to the wastewater. There is market for Lupanine and Spartein. But instead of extract they dispose of the brackish water in the sewers.
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Hi Hector,
May be you can do it your self using SPE protocol in this paper.
You have an overview of the method recovery and matrix effect.
I hope this helps!
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In the near future some non-biodegradable materials will be replaced in production processes for other, biodegradable. For example, plastics in the European Union until 2021 are to be withdrawn from packaging and replaced with other biodegradable materials such as paper or packaging produced from food, eg from cereals. But this is just the beginning of the revolution in the development of pro-ecological material innovations. This is only the first step towards the withdrawal of plastic as one of the main factors of littering the natural environment.
Do you know other types of examples already implemented or planned to implement projects to replace plastics with biodegradable materials?
Which biodegradable materials will be replaced in the future by plastic that is being phased out of production?
Please, answer, comments. I invite you to the discussion.
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Very interesting topic. In my opinion, bioplastic may a more realistic / alternative solution since the actual research works are focusing on the possibility to elaborate bioplastic from renewable resources, which will have the characteristics to be biodegradable / recyclable.
Here's in attached a recent article treating the economical potential of bioplastic.
Best wishes,
Sabri
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It is difficult to determine the volume % of Cpx, Olv, and Opx in mylonitic peridotites and very fine grained ones. Sometimes, Cpx, Olv and Opx % can be estimated from bulk chemistry based on CIPW norm.
I need trusted spreadsheet for CIPW calculation. Thanks so much.
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Hello, here is the spreadsheet for CIPW calculation.
Best regards, Zilong
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Hello everyone,
Recently, I've been confused about how to calculate the needed weight equivalent from the hydrated salt MgCl2.6H2O (M.W=203.3) to match the final concentration of 1mM from the anhydrous salt of MgCl2 (M.W=95.2), in the same volume of H2O (1L).
Should I just keep the final concentration as it is for both of these salts and only use the molecular weight of MgCl2.6H2O (M.W=203.3), leading to this calculation >> g=M*M.W*V=1mM*203.3*1=0.2033 g/L?
Or should I use the conversion factor obtained from dividing the molecular weights of both salts (203.3/95.2=2.14), then use it to recalculate the final concentration for the use of MgCl2.6H2O instead of MgCl2 then calculate the needed weight within the same volume (1L) which will be 2.14mM*203.3*1=0.4351 g/L?
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Your "conversion factor" is actually a "confusion factor". Let's go back to basics here:
  • 1 mole of MgCl2 has 1 mole of Mg2+, 2 moles of Cl- (total molecular weight 95.2)
  • The hydrated salt MgCl2.6H2O has 6 moles of H2O per mole of MgCl2 (m.w. is now 203.3 because of all the water molecules).
  • 1 millimole will be 95.2 x 0.001 = 0.095 g. When dissolved in 1 litre of MgCl2, this is 1 mM of Mg, 2mM of Cl.
  • 1mM of MgCl2.6H2O will be 203.3 x 0.001 = 0.203 g in 1 litre. Same mass of Mg and Cl, but there is water weighed with the salt as well.
You can check your calculations by using the Mg/MgCl2 ratio e.g. 24.3/95.2 = 25.5% (of the 0.095g will be 0.0242 g of Mg2+). (Is this where you got confused?)
Similarly, 24.3/203.3 = 11.9% (of the hydrated 0.203 g is ... 0.0242 g of Mg2+).
This should be found and probably explained better than what I have written in most(!) undergraduate textbooks.
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Hello,
currently I'm implementing a battery degradation model (for li-ion/LFP-tec) to an existing energy management optimization framework in stationary context.
Because stationary battery racks are often located in ground floor of a building where the environmental temperature is not fluctuating so much, I assume that the actual operating temperature of the battery might be in a pretty narrow range.
My question would be if that's the case and if yes about which temperature range we're talking. The idea behind is to decide how exact temperature-aging-dependencies should be implemented into the degradation model or if it is possible to almost ignore them because stationary batteries are operating in a very narrow range.
Unfortunately during my research I only found information about best suitable temperature ranges for specific battery chemistries or how temperature influences battery degradation until now.
Thank you very much in advance!
Best,
Antonia
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With benzene ring as a typical aromatic structure, the uncompromising hydrogenation (ring saturation without altering the non-aromatic functionality such as the -OH and the -C=O) of benzene derivatives: phenol, benzyl alcohol, benzoyl moiety, aniline, etc. is well known.
However, little, if any, is documented about the reverse reaction. Have you come across or thought of the uncompromising dehydrogenation of the corresponding aliphatic (cyclohexane) derivatives to the benzene derivatives? If yes, please share your experiences, papers, weblinks, ideas, and so on.
Thanks in advance!
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Dear Stanislaus O. Okwundu thank you for sharing this very interesting chemical question with the RG community. As a synthetic inorganic chemistry I absolutely not an expert in this area of research. However, I at least found two literature references which at least come close to answering your question in part. Both describe the dehydrogention of cyclohexylamine under formation of aromatic amines. Please have a look at these articles:
A Ni–Mg–Al layered triple hydroxide-supported Pd catalyst for heterogeneous acceptorless dehydrogenative aromatization
and
Versatile routes for synthesis of diarylamines through acceptorless dehydrogenative aromatization catalysis over supported gold–palladium bimetallic nanoparticles
The second paper is even freely available as public full text. You can find and access other related articles by searching the "Publications" section of RG for the term "dehydrogenative aromatization":
Other articles are found when searching for terms like "acceptorless dehydrogenative aromatization". When searching for literature references, I think you should better avoid the term "uncompromising" as in your original question. This word seems to be rather unusual in this context.
I hope this helps. Good luck with your work and best wishes, Frank Edelmann
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For my artificial intelligence study, I need to create a database of chemistry molecular compounds. So, I am in search of free open software or tools which can help to collect and create the database of the chemistry molecular compounds. Some suggestions or tips would be appreciated. Thanking you.
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I know about a free tool with the name ACD ChemSketch which can be used to generate 2D and 3D chemical structures.
I have a created a course for learning this tool. Check it out at https://drravirawat.wordpress.com/the-art-of-writing-chemistry-in-electronic-notebooks/
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Given the absorbance spectrum, how could one calculate concentration using the slope (tangent) of linear part of that spectrum (e.g. from 300 nm to 450 nm is linear)
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This method has no benefit that I can see over the usual method of measuring the absorbance at a single wavelength and applying Beer's Law. It is also unrealistic in that absorbance spectra typical lack linear parts, except as approximations over short wavelength ranges. Nevertheless, below I examine the proposed method in detail.
Consider the absorption spectrum of a substance S in a dilute solution, such that Beer's Law pertains and the absorbance at any wavelength is directly proportional to the concentration. The constant of proportionality is called the extinction coefficient.
For the slope measurement, choose any 2 wavelengths (lambda 1 and lambda 2) at which the solution has a non-zero absorbance. The difference betwen the 2 wavelengths is Delta lambda. Measure the absorbances (A) of the solution at each wavelength: A1 and A2. If you draw a line between these two points on the spectrum, as for any two points in a plane, you can measure the slope of the line as (A2-A1)/(Delta lambda).
Now consider a solution of twice the concentration as before. Its absorbance values at the same two wavelengths will be 2A1 and 2A2, because for dilute solutions the absorbance is directly proportional to the concentration, according to Beer's Law. The slope of the line between the two points on the spectrum of this solution will be (2A2-2A1)/(Delta lambda) = 2(A2-A1)/(Delta lambda).
Thus, the slope of the line between the two points increases in direct proportion to the concentration. The result of the comparison of the spectra by this method is that you have determined the ratio between the concentrations of the 2 solutions, but not the actual concentrations. To get the actual concentrations, you either need to know the concentration of one of them to begin with, or to know the extinction coefficients at the two wavelengths.
Notice, by the way, that this calculation did not require that the two selected points on the spectrum lie along a linear portion of the spectrum. They could be anywhere on the spectrum. More to the point, the calculation achieved the same result as a measurement made at a single wavelength.
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In the structure of many drugs, there is a carboxylic group
What is the significance of this group? Why should it exist in the structure of a drug?
Do you know any article or book or reference about this subject?
Thanks a lot
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Nalidixic acid - A NSAID grs of drugs or pain killer .REF : en.wikipedia.org ( Image Source ) .
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Greetings
It is very difficult for me to choose between these two majors for the master's degree
Although I think this is a question for many other students as well
Regardless of interest, which of these two disciplines do you think has a better future? Which has more job markets, in the US and Europe? Which one is more suitable for studying abroad? And which one has more income? Are jobs related to organic chemistry less than analytical chemistry?
Please share with me if you have information about these two fields and their job market.
Thanks
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The subject of specialisations does not depend on the feature income rather your subject if interest . Organic chemistry has too much scopes as a synthetic( R&D) chemist in multinational pharmaceutical houses like Chem biotech , Pfizer , DRL labs etc etc. Even in post doc level abroad from India very high scope in organic nano synthesis like CNT . So scope of income is naturally very high in organic chemistry indeed . But in analytical chemistry the scope is narrow compared to organic chemistry . Since analytical and quality control laboratories are also guided by organic chemists / phyto chemists / petrochemicals for mainly UV-Visible spectrophotometric analysis / Chromatography like GC , HPLC , HPTLC , GC-Mass spectrophotometer and fluroscence spectroscopy .Yes analyical chemists are useful in effluent treatment / waste water analysis as well as drinking water analysis of trace heavy metals like Cu , Cd, As , Pb , Hg ( II , I ) by AAS ( Atomic abs Spectrophotometry ) AES ( Atomic emission spectrophotometry. In drinking / waste water lab there are so many important analytical parameters like B.O.D , C.O.D , D.O , pH , TDS , TSS and limit tests for heavy metals in trace metals .
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Kindly discuss your ideas and viewpoints on the origin of life and the RNA world hypothesis.
What are the contradictory views on why researchers are still unsure about the origin of life through RNA or such analogous molecular intermediate pre-cursors preceding its existence?
"The general notion of an “RNA World” is that, in the early development of life on the Earth, genetic continuity was assured by the replication of RNA and genetically encoded proteins were not involved as catalysts. There is now strong evidence indicating that an RNA World did indeed exist before DNA- and protein-based life. However, arguments regarding whether life on Earth began with RNA are more tenuous. It might be imagined that all of the components of RNA were available in some prebiotic pool and that these components assembled into replicating, evolving polynucleotides without the prior existence of any evolved macromolecules. A thorough consideration of this “RNA-first” view of the origin of life must reconcile concerns regarding the intractable mixtures that are obtained in experiments designed to simulate the chemistry of the primitive Earth. Perhaps these concerns will eventually be resolved, and recent experimental findings provide some reason for optimism. However, the problem of the origin of the RNA World is far from being solved, and it is fruitful to consider the alternative possibility that RNA was preceded by some other replicating, evolving molecule, just as DNA and proteins were preceded by RNA." - Robertson and Joyce
[This is as per the explanation by Michael P Robertson and Gerald F Joyce in the article: "The origins of the RNA world." published in the Cold Spring Harb. Perspect. Biol. 4, a003608 (2012).]
The scientific community must resolve this contradicting conjecture through rational discussion and debate backed by strong experimental evidence on what must be the pre-cursor molecule to the Origin of Life if it is not RNA!
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Dear Mrutyunjaya,
I am not really in a position to assess the likelihood of an RNA World scenario for the origin of life on Earth. However, I would like to point out that from an astrobiological standpoint, I think that we should keep an open mind on the huge variety and broad range of potential (evolutionary) pathways leading to life. Moreover, a lot also depends on the precise definition of "life" and from which stage or time onwards we classify certain phenomena as "life". If life exists outside of Earth, it may look very different to what we have become accustomed to on our "pale blue dot". Once we have confirmed at least a second, independent instance of a living system in the universe, we may also see clearer on how probable a RNA World scenario may have been for the case of Earth (even if we may never be able to reconstruct and verify the exact pathway...).
Thanks & all the best,
Julius
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I understand that in a galvanic cell, electrons in the form of an electric current can reduce various ions such as Cu(2+) to Cu(s). I am wondering if this same chemistry would apply to redox enzymes, and if applying a negative charge to a redox enzyme could change it from its oxidized state into its reduced state, or if the reduction of an enzyme is more complicated than this and requires the necessary reactants. Thanks.
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Hi, this paper is useful for you about this question:
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Yesterday I have read a news stating that The embryo fossil, nicknamed “Baby Yingliang,” was discovered in Ganzhou, Jiangxi Province in southern China, and is believed to be at least 66 million years old. Researcher Dr. Fion Waisum Ma told the AFP news agency that the discovery is “the best dinosaur embryo ever found in history” (globalnews, 2021).
Although there were several discoveries of Dinosaur components such as:
Eggs
DNAs from thier remains
are frequently being discovered, Since the biotechnology development is in its Zenith at 2022, Why nobody has attempted to create a dinosaur?
What type of scientific constraints would be encountered in such a laboratory experiment?
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The science fiction book Jurassic Park and the movies based on it are about recreating dinosaurs by extracting their DNA from the guts of dinosaur-biting insects trapped in amber.
DNA is not sufficiently stable to survive for the necessary 65 million years or longer since dinosaurs roamed the Earth, so dinosaur DNA is not available. What you would do with it, if you could get it, in order to recreate dinosaurs is another issue.
The oldest DNA ever recovered was recently reported from 1.2 million year old mammoth teeth in Siberia.
It has been seriously proposed to recreate mammoths, which went extinct several thousand years ago. Mammoth DNA is available from animals preserved in permafrost.
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I am able to attend two conferences/events with a focus on gas chromatography in 2022. Do you have a recommendation? Preferably in the US, and in the field of chemistry, safety, environment, fire or forensics.
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Today, introducing a fluorine atom into a biologically active molecule seems to be a valuable approach in the process of drug discovery.
What are the most challenges problems faced by the chemistry of Fluorine in Drug discovery?
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Dear Alexander Sinko many thanks for sharing this very interesting technical qustion. Unlike some other RG members I will give you only one answer at the moment. First of all, I would not worry about the toxic and hazardous nature of elemental fluorine, as I assume that you are most likely not equipped to handle elemental fluorine anyway. The potential toxicity of fluorides does not present a big problem either because you are certainly not planning to eat your compounds, right? There are, however, some simple fluoro-organic compounds which are really toxic. The most (in)famous example is monofluoroacetic acid and its salts. Besides, many fluorinated precursors are commercially available and easy to handle. A very nice aspect of introducing fluorine atoms into biologically active molecules is that it adds another NMR-active nucleus (19F). Moreover, fluorine-substitution can also improve the solubility and volatility of organic molecules (the latter aspect is important for mass spectrometry).
In this sense I wish you good luck with your own work. Please stay safe and healthy! With best wishes, Frank Edelmann
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Hi Academics,
Kindly could you clarify the meaning of the term " Researcher"?
Best.
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In my opinion, a true researcher is someone who try to find solutions for the well-being and prosperity of humanity and not to serve individual / personal interest.
That's why a good researcher should be modest, generous and have perseverance since this capacites or should I say personality traits make (in my own vision) a huge difference to qualify a person as a reserahcer since intelligence / competence alone are not enough.
Best wishes,
Sabri
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CO2 is used as raw material for chemical syntheses. It paves the opportunity to mitigate the greenhouse gas (GHG) emissions. However, it is not mathematically or logically proved yet that carbon capture benefits the environment in terms of resource efficiency. In my opinion, I believe that the life cycle assesment (LCA) would be the most suitable tool to quantify the resource-based benefits due to carbon based methane (CH4) production and to prove the resource efficacy of carbon capture.
I would like the researchers who read this discussion to provide their own ideas on whether LCA is the most suitable tool to identify the carbon capture resource efficacy or are there any methods better than LCA that can be applied on CO2 based methane production.
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"Life cycle assesment (LCA)" could be jointly addressed with the "circular economy (CE)" and the "ecosystem service valuation (ESV)", as an integrated tool to "quantify the resource-based benefits due to carbon based methane (CH4) production". Besides, this integrated approach can better control the excessive use of material, lowering the energy needs for new products, saving natural sources from overexploitation and environmental degradation, managing labour's capital, and proving the resource efficacy of carbon capture.
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I'm currently looking at the rheological properties of the polymer Xanthan Gum. focusing on its dynamic viscosity to be more specific. I'm assessing the effects of pH (ranging from 3.6 to 5.6, 0.4 increment, total of 6 pH's) on the dynamic viscosity of xanthan gum solution (dissolving xanthan gum powder into acetic buffer with equal ionic strength, concentration is kept at 0.04%).
Firstly, my viscosity data collected shows that, as pH increases from 3.6 to 4.0 then 4.4, the viscosity increases; but as I bring up the pH from 4.4 to 4.8, 4.8 to 5.2, then lastly 5.2 to 5.6, the increasing viscosity trend plateaus and the increase in viscosity is less significant compared to the 3.6-4.4 jump. At this range, does pH has an effect on the viscosity of xanthan gum based on its molecular configuration? Though some sources states that xanthan gum's viscosity remains stable and unchanged within the range of pH 3-12 at a high concentration like 1% not 0.04%, yet some suggest pH still plays an effect, though I'm not sure how on the chemical and molecular aspect.
A possible conjecture I can think of is the xanthan gum's order-disorder and helix-coil transition is affected by protonation. In figure 2, it demonstrates how electrolytes affect the structure of the polymer; in figure 3, it shows how at a state of a helical rod and no longer a random coil, it is capable to hydrogen bonds among each other. Hence, I'm wondering of pH plays an effect on it's structural transition, such that the increased intermolecular forces at the form of a helical rod would make it more viscous in solution.
Here are the resources I have used so far:
Brunchi, CE., Bercea, M., Morariu, S. et al. Some properties of xanthan gum in aqueous solutions: effect of temperature and pH. J Polym Res 23, 123 (2016). https://doi.org/10.1007/s10965-016-1015-4
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Dear Ryan Lo, you may find various stufies on this topic. Please have a look at the following free access RG fille. My Regards
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I am involved in a project to develop online software which simulates scientific instruments (such as absorption spectrometers) and chemistry experiments for science students (post 16 years) which is featured in the latest edition of Chemistry International (see following link):
Students can work their way through these online exercises producing data from the simulator, analyse that data and compile a laboratory report on their findings from anywhere that has an internet connection. We already have registered users from various institutions around the world incorporating these simulations into their degree programs.
1. I would be interested in the views of colleagues about the educational value of using our software, in general.
However, more specifically, I would also be interested to know how colleagues feel about the following:
2. Will this help to widen access to a science education, particularly for students from disadvantaged backgrounds?
3. As a company, we are eager to get involved with schemes/organisations that promote widening access to a science education. Can colleagues suggest how we might best go about this by identifying relevant organisations that may be interested in working with us/using our software?
We are a UK based company but would happily collaborate internationally with interested partners.
Delighted to receive any other comments/views.
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Very promising
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How long does it take to a journal indexed in the "Emerging Sources Citation Index" get an Impact Factor? What is the future of journals indexed in Emerging Sources Citation Index?
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According to Web of Science, ESCI Journal can be included in Science Citation Index (SCI), Social Science Citation Index (SSCI), or Arts and Humanities Citation Index (AHCI), if they meet "Impact Criteria".
Accordingly, journals are included in Web of Science Core Collection (SCI, SSCI, AHCI, and ESCI) if they meet 2 criteria, namely; 1) Quality 2) Impact. The "Quality criteria" comprises 24 sub-criterion, while the "Impact criterion" consist of 4 sub-criteria.
Hence, any journal captured in ESCI have already meet the quality criteria , therefore the quality criteria is the only requirement for journal to be considered in ESCI. Similarly, any journal on ESCI must wait to meet the "Impact Criteria", which can take time, and may be impossible to be predicted. This is because the Impact Criteria is evaluated according to the number of citations the journal is receiving, the performance of authors who published in the journal before, and the number of cross-references between journals in web of science, etc. Waheed Ur Rehman .
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How can we manage PH. control in a best possible way to form struvite in synthetic water? From PHREEQ, thermodynamic solubility limit can be calculated. However, we still not sure, if playing around to that PH can make your struvite.
So how can we be sure the right PH to precipitate it out (even considering synthetic water)? It might be the case, you reach your higher supersaturation at even higher PH than required? Please guide...
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Dear Salman Amjad thank you for posting this interesting technical question on RG. In fact, the influence of the pH value on the formation struvite in synthetic water has been studied previously. For example, please have a look at the following potentially useful article which might help you in your analysis:
Conductimetric study of struvite crystallization in water as a function of pH
This paper has not yet been posted as public full text on RG, but I assume that you have access to the full text through the university library. If not, you can request the full text directly from one of the authors via RG.
The following articles are freely available as public full texts on RG:
Struvite formation, analytical methods and effects of pH and Ca(2+)
and
Influence of pH and Temperature on Struvite Purity and Recovery from Anaerobic Digestate
I hope this helps. Good luck with your experiments and best wishes, Frank Edelmann
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For microbial lipase assy which is the best method titrimetric or spectrophotometric method
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UV-VIS spectrophotometry will be reliable.
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American Chemical Society (ACS) has provided a solvent selection tool for chemistry reactions from the perspective of Green Chemistry. Have you any idea how to operate the tool or any informative video? Here is the link to the tool. https://www.acs.org/content/acs/en/greenchemistry/research-innovation/tools-for-green-chemistry/solvent-tool.html
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Please fo thru this for proper usage information
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Excess of fluoride content in drinking water (more than 1.5mg/L) sourced from inland water bodies causes dental fluorosis and skeletal fluorosis. Although reverse osmosis (RO), electrodialysis, and distillation are available for deflouridating inland water bodies. However am not sure that how effective these methods can be used to deflouridate groundwater. I would like to hear some suggestions on the mechanisms effective at deflouridation of groundwater.
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Deflouridation techniques are simple and can be explained like Bone charcoal, contact precipitation, Algona, activated alumina, ion-exchange technology, membrane filtration, nanofiltration, and clay are all methods for defluoridating water that can be used. Reverse osmosis (RO), electrodialysis, and distillation are examples of cutting-edge treatment methods.
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Generally observed at low strain rate for fine grained material.
For industrial scale
which are viable materials?
which parameters need to alter?
Kindly express your views.
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Agree with Mohammad Abboud sir
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Hi everyone,
Sorry if the question is too basic, I want to know why Struvite recovery is to be done in such a way that salt solutions are made separately and then mixed? Why we cannot put, the salts all in a known volume and then just increase the Ph to create supersaturation?
and please, as I started with the phosphorus recovery project, would like to get advice to understand its thermodynamics and chemistry ? any useful material to follow, please share.
Thank you.
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Dear Salman Amjad thank you for posting this very interesting technical question on RG. As a synthetic inorganic chemists I'm not really a proven expert in this field of research. However, there are a few relevant and potentially useful references about this topic available in the current literature. For example, please have a look at the following articles:
Phosphorus recovery by struvite crystallization in WWTPs: influence of the sludge treatment line operation
Phosphorus recovery through struvite crystallisation: Recent developments in the understanding of operational factors
These two articles have not yet been posted as public full text on RG. Please check if you can access them through the OvGU library.
There is also an entire book chapter about this research topic available which can be freely downloaded as full text (after free registration):
Phosphorus Recovery by Struvite Crystallization from Livestock Wastewater and Reuse as Fertilizer: A Review
I hope this information is helpful. Good luck with your research and please stay safe and healthy. With best wishes, Frank Edelmann
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Kindly express your views what we can decipher from Storage modulus and tan δ.
w.r.t. to failure mechanism, tribological performance etc.
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These are great questions!
Storage modulus is related to the amount of elastic structure in the sample and the higher it is, the more solid like the material is (as opposed to liquid like). If the storage modulus exceeds the viscous modulus, the material will usually ultimately fail by breaking elastically rather than being viscously pulled apart. I say usually, as these moduli are determined usually in the linear viscoelastic region (LVR) of the material whereas destructive tests are outside of the LVR of the material.
The ratio of viscous modulus to elastic modulus is also the Tan delta. Therefore if Tan d is below one, the sample is solid-like and if above 1 then liquid-like (although it may be a very stiff liquid).
With regard to tribology, I have less information, however some assumptions may be as follows. If a grease, the elastic modulus would need to be high enough to prevent the material from flowing under it's own weight (and be able to start up flow at all likely environmental temperatures). You may want the viscous modulus to be higher for a system where there are high shear forces eg in a wind turbine (to prevent scratching etc) , whereas it should be lower viscosity (and lower modulus) for a lighter stress application, eg a small motor. People often use a Stribeck curve to mimic an application and measure the friction / lubricity of a surfaces or lubricant.
I hope this helps.
Best regards,
Phil
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As every keyword have certain experts associated with it, based on their area of expertise. Can we initiate a devoted section for research collaboration, especially for the calls requiring bilateral or multinational collaborator?
Presently, My group is looking for a German collaborator in the area of " High performance based C-C composites" on following call "