Chemistry - Science topic

Sayantan Mukherjee

Nanofluid is a technical term. For example, a dispersed system of magnetite nanoparticles in kerosene is called a nanofluid. A dispersed system in kerosene is a heterogeneous system that consists of two phases of magnetite nanoparticles and kerosene . This system can be studied in chemical thermodynamics. The enthalpy and entropy of such a system cannot be theoretically and experimentally determined. You can only determine their change in some process. For example, we can determine their change if we study the process of compression of such a system from atmospheric pressure to 100 atm.

The entanglement of nanofluids is related to quantum mechanics.

A heterogeneous system of surfactant/water spherical micelles can be attributed to nanofluids. Such a system may have quantum entanglement. It is too long to explain this process on these pages. One must first understand the entanglement of two quanta, decoherence, quantum fluctuations, Schrödinger's cats...

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Achievement Goal Theory is a psychological framework that aims to explain how individuals' goals and motivations influence their behavior and performance in achievement settings. The theory suggests that individuals adopt different goal orientations or achievement goal orientations, which shape their behavior and responses to achievement-related situations.

Students with a mastery goal orientation are primarily focused on developing their skills, mastering new knowledge, and improving themselves. While students with a performance goal orientation are primarily focused on demonstrating their competence and outperforming others.

Developed by John Nicholls and Carol Dweck in the 1980s and has been widely studied in the context of education, particularly regarding academic achievement among students.

محتمل

Hi Mariah,

for cross-national funding programs in your field, asking the respective embassies might help.

If you're interested in the acceptance rates for the Journal of Materials Chemistry C or any other Royal Society of Chemistry (RSC) journal, I recommend visiting the official RSC website or the specific journal's website for the most up-to-date information. Journals often publish their acceptance rates or may provide information on their peer review process, which can give you a better understanding of their publication standards.

R = K[A][B]

Rahim,

They're certainly original.

But I've read the 'mission statement' of BEN, and can find no compelling reason to submit work there.

Indeed, here's one reason to not submit to the journals run by Prof. Aydin:

I quote from:

"An artificial intelligence based English proof system checks the language of the paper."

Mmm.

Call me old-fashioned, but it shouldn't be too hard to find someone to read a submission who is a native english speaker.

I've used with great success for everything IR search: KnowItAll Analytical Edition Software - Wiley Science Solutions

I know this feed is old, but I'm working with CDK and trying to discern FP37 with a similar issue and cannot seem to find any resources on the matter.

Have you found a suitable reference since posting this?

Thanks in advance!

The question is of whether the cellulose might become soluble in aqueous based solutions such as some foods, when the utensils or containers are held together by the cellulose. A waterproof outer lacquer might be needed.

Cellulose analogues are used in medications as a binder/release timing instrument for the active pharmaceutical ingredient. Cellulose is also used in foods, such as grated Parmesan cheese, to absorb moisture to keep the cheese flakes from caking and so they flow properly.

Dear friend Atefeh Shiri

The wavelength of maximum absorption for glycerol monostearate can vary depending on the solvent used and the concentration of the solution. However, a study published in the Journal of Lipid Research found that the maximum absorption wavelength for glycerol monostearate in methanol is around 230-235 nm. (Reference: https://www.jlr.org/content/16/6/674.abstract)

It is important to note that the specific wavelength of maximum absorption may vary depending on the instrument used and the experimental conditions, so it is recommended to conduct a calibration curve using different concentrations of glycerol monostearate and measuring the absorbance at different wavelengths in order to determine the most suitable wavelength for quantification.

In the case where you are comparing two or more spectra or peaks and the absolute value of the absorbance is not critical to what is being reported, then arbitrary units should be acceptable. This is generally done to avoid unnecessary complexity in the plots of data.

Yüzeydeki silisyum dioksit tabakası temizleme sırasında oksitlenmiştir. Tabaka saf silisyum dioksit ile temizlenmeye çalışılmalıdır.

Dear friend Boeun Choi

Indium nitrate hydrate is said to be water soluble, but it does not dissolve well both in deionized water and organic solvents above 20 mM. One possible reason for this is that the indium nitrate hydrate is not pure (4.4 Solubility - Chemistry....). Another possibility is that the indium nitrate hydrate is not being dissolved properly. You can try dissolving it in hot water or by adding a small amount of acid (Indium(III) nitrate 99.9 trace metals...).

I hope this helps! Let me know if you have any more questions.

Source:

(1) Indium(III) nitrate 99.9 trace metals 207398-97-8 - Sigma-Aldrich. https://www.sigmaaldrich.com/US/en/product/ALDRICH/326135.

(2) Solvent properties of water (article) | Khan Academy. https://www.khanacademy.org/science/biology/water-acids-and-bases/hydrogen-bonding-in-water/a/water-as-a-solvent.

(3) What Happens When Salt Is Added to Water? | Sciencing. https://sciencing.com/happens-salt-added-water-5208174.html.

(4) How can i dissolve Sodium Nitrate in organic solvents?? - ResearchGate. https://www.researchgate.net/post/How-can-i-dissolve-Sodium-Nitrate-in-organic-solvents.

(5) 4.4 Solubility - Chemistry LibreTexts. https://chem.libretexts.org/Courses/Purdue/Purdue:_Chem_26505:_Organic_Chemistry_I_%28Lipton%29/Chapter_4._Intermolecular_Forces_and_Physical_Properties/4.4_Solubility.

Yes, there are several purine-based ionic liquids that have been described in the scientific literature.

Examples of purine-based ionic liquids include 1-butyl-3-methylimidazolium adenosine monophosphate ([BMIM][AMP]), which was first synthesized and characterized in 2011 (reference: "Synthesis and characterization of a new purine-based ionic liquid: 1-butyl-3-methylimidazolium adenosine monophosphate" by L. Zhao et al., in Tetrahedron Letters, vol. 52, p. 1130-1133, 2011).

Other examples of purine-based ionic liquids include 1-butyl-3-methylimidazolium guanosine ([BMIM][GMP]) (reference: "Synthesis and characterization of a novel purine-based ionic liquid: 1-butyl-3 -methylimidazolium guanosine" by L. Zhao et al., in Journal of Molecular Liquids, vol. 170, p. 63-66, 2012) and 1-allyl-3-methylimidazolium hypoxanthine ([AMIM][Hpx]) (reference : "Synthesis and Characterization of a New Purine-Based Ionic Liquid: 1-Allyl-3-methylimidazolium Hypoxanthine" by L. Zhao et al., in Chemical Research in Chinese Universities, vol. 32, p. 157-161, 2016) .

Having tested a lot of essential oils for this specific purpose, I can ensure you that different essential oils give very different results. There is also a possibility that fumigation doesn't kill the adults but stops the developements of the eggs inside the grains.

Way of applying the product (fumigation, direct spraying...) also gives different results, so there is no easy direct answer to your question

You`re Welcome, dear Friend.

Well, if your teacher said that the valence orbitals play the major role in the bond formation, that would actually be pretty close to most current models as the core electrons are just shifted a little in energy. Of course the frontier orbital method used in 1980s organic chemistry is outdated, or as Fleming's newer textbook phrases it, "had no [physical] right to function as well as it did", and of course there is the radical statement "there is no physics in orbitals", but when you ask people who insist upon that what they use instead, the room usually turns pretty quiet.

I wouldn't see this as a major problem in secondary education, though, especially since this question here was about laboratories.

Both Origin software and X'Pert HighScore software can be used to determine the hkl values of a crystal structure. Here are the steps to follow for each software:

Using Origin software:

1. Open the data file in Origin software and select the graph containing the diffraction pattern.

2. Click on the "Peak Analyzer" button in the toolbar.

3. In the Peak Analyzer window, select the peak of interest by clicking on it.

4. In the "Peak Information" tab, note down the "2Theta" value and the "Counts" value for the peak.

5. Use the Bragg's law equation (2dsinθ = nλ) to calculate the d-spacing value for the peak. Here, n = 1 for first-order diffraction. λ is the wavelength of the X-ray used in the experiment.

6. Use the d-spacing value to calculate the hkl values for the peak using the Miller indices formula (hkl = [n1d1,n2d2,n3d3]).

Using X'Pert HighScore software:

1. Open the data file in X'Pert HighScore software and select the diffraction pattern.

2. Click on the "Peak Fitting" button in the toolbar.

3. In the Peak Fitting window, select the peak of interest by clicking on it.

4. In the "Peak Information" tab, note down the "2Theta" value and the "d-spacing" value for the peak.

5. Use the Bragg's law equation (2dsinθ = nλ) to calculate the wavelength of the X-ray used in the experiment.

6. Use the d-spacing value to calculate the hkl values for the peak using the Miller indices formula (hkl = [n1d1,n2d2,n3d3]).

Great idea Ramin, it can solve not only the chemistry related and also bio- chemistry related problems also

Dear Sir you may try the protein separation with foam fractionation coloumn. it would suppose to help you

Greetings Ali Safaa

To solve for molarity (M) in the equation:

ppm = M x m.wt x 1000

We can rearrange the equation as follows:

M = ppm / (m.wt x 1000)

So if you have a solution with a concentration of 50 ug/ml and you want to know the molarity, you would first need to know the molecular weight of the solute. Let's say the molecular weight is 100 g/mol.

50 ug/ml x 1000 = 50,000 ppm

M = 50,000 ppm / (100 g/mol x 1000)

M = 0.5 M

Therefore, the molarity of the solution is 0.5 M.

It is important to note that ug/ml and ppm are not equivalent units of measurement. Ug/ml is a unit of concentration based on mass per volume, while ppm is a unit of concentration based on the number of parts per million. To convert from ug/ml to ppm, you would need to know the density of the solution and the molecular weight of the solute.

For filtering chitosan solutions, it is recommended to use a filter with a pore size of 0.2 µm or smaller

One suitable filter for this purpose is a syringe filter with a 0.2 µm pore size, made of materials such as nylon, PVDF, or PTFE. These filters can effectively remove particles and aggregates from chitosan solutions without causing clogging or loss of chitosan

@Ed Gerck

Irrational numbers are uncomputable with probability one

================================================= ===

My deepest apologies, but I have read your Answer dated December 14, 2022 in the FLT thread https://www.researchgate.net/post/Are-there-other-pieces-of-information-about-Victory-Road-to - FLT#view=641367549777ccc70c026256/234 .

There was a link to your own thread given by you. This thread gives your erroneous statement from the very beginning, namely: "Irrational numbers are uncomputable with probability one".

Please agree, Dear Professor Ed G., that any irrational number is calculated with 100% accuracy with a probability of 1 for any number of orders p-1, if you write down p orders. Thus, if you write for the root of 2 one order before point and three orders after point, you will have sqrt(2)=1.414..., i.e., you can consider that you have written 4 orders. At the same time, the accuracy of 100% with a probability of 1 is provided for 3 orders, i.e. 1.41, etc., for any number of orders...

Speaking of some kind of all orders "full notation" , as you would like to see it, it's not possible for such a representation of irrational numbers.

If you point out my mistake to me, I will be grateful.

Greetings,

SPK

Hello Noor Ul Ain ,

Your copper nitrate trihydrate is a deliquescent salt, which means that it will absorb water from the atmosphere and eventually liquify. The only way to slow down this process is to store the bottle containing the salt in a sealed descicator backfilled with dry nitrogen gas. Every time you take out and open the bottle to use some of the salt, you should backfill the bottle with dry nitrigen gas before you screw the bottle lid back on and place the sealed bottle back in the descicator, which you refill with dry nitrogen gas.

Regards,

Tom Cuff

Can you be more specific? What is "repositioning" and to what "drugs" do you refer?

Since you're located in a pacific country, maybe check out if the PacifiChem has the right segment for you.

i don't know

Hi, you already got the topology file (itp), so you don't need topology.

In your case, just create the protein topology using pdb2gmx and then combine it later. YOu should follow this tutorial:

Just consider the thiol group as a ligand. If you have downloaded it from the ATB, then, I hope the structure and charges are already optimized.

Good luck.

Treating bark with acid (HCl) first and then with base (NaOH) second is a common method for isolating plant compounds for analysis or extraction, such as tannins, lignin, and cellulose. This method is known as acid-base treatment or A/B extraction.

The reason for this order of treatment is that acid treatment hydrolyzes and breaks down the plant cell walls, making the cell contents more accessible for extraction. Acid treatment can also help to remove impurities, such as pigments and waxes, from the sample.

After acid treatment, the sample is then neutralized with a base, typically sodium hydroxide (NaOH), to restore the pH to a neutral or slightly alkaline state. The neutralization step is important to prevent the acid from interfering with subsequent analytical techniques or reactions.

The use of acid and base treatments in this order allows for selective extraction of different plant compounds based on their solubility and chemical properties. For example, tannins are more soluble in acidic solutions, while lignin and cellulose are more soluble in basic solutions.

Treating the bark with base first would result in a saponification reaction, where the ester linkages in the plant compounds would be hydrolyzed by the base, resulting in a loss of their original structure and properties. Therefore, treating the bark with acid first and then with base is the preferred order for A/B extraction of plant compounds from bark.

Maria Anna Dzierżyńska, ma'am you can try AutoGrow4. It uses a genetic algorithm to evolve predicted ligands on demand and is not limited to a virtual library of pre-enumerated compounds. It can also be used to generate entirely novel drug-like molecules and for optimizing preexisting ligands.

The effect of diluent on nitrosamine recovery can vary depending on the specific diluent used and the chemical properties of the nitrosamines and drug substance. In some cases, the presence of certain solvents or diluents can enhance the recovery of nitrosamines, while in other cases, they can have the opposite effect and decrease the recovery.

Regarding your specific question about candesartan cilexetil, the reason why you are getting good recovery of certain nitrosamines in water but not in methanol could be due to differences in the solubility and chemical properties of the drug substance and nitrosamines in the two solvents.

Candesartan cilexetil is generally considered to be insoluble in water, but it is possible that certain impurities or components in the drug substance could be soluble in water and thus affect the recovery of nitrosamines. On the other hand, methanol is a more polar solvent that may interact differently with the drug substance and nitrosamines.

In addition, the specific nitrosamines in question, NDIPA and NDPA, have different chemical structures and properties, which could affect their solubility and recovery in different solvents. Without more detailed information about the specific experimental conditions and methods being used, it is difficult to provide a definitive answer.

However, in general, factors such as solvent polarity, pH, and temperature can all affect the solubility and recovery of nitrosamines and other impurities during the extraction process. Careful selection of appropriate solvents and optimization of extraction conditions are important to ensure accurate and reliable measurements of nitrosamines and other impurities in drug substances.

Hi Tristan, in my experience with carbonate ramps the role of algae would be secondary to other factors that would, in fact, control the type and distribution of algae. These factors would include the slope of the surface that the ramp grows on and climatic conditions. One good outcrop example comes to mind that you might want to check out: The Permian San Andres (note: not a misspelling of San Andreas) carbonates occur as a series of ramps that gradually give way upward into a rimmed shelf capped by the famous Capitan Reef of Guadalupe Mountains National Park. The literature is voluminous so you could research the role of algae in the ramps vs. rimmed shelves and maybe see something no one has thought of before. Cheers!

Hydrothermal vents and lava flows can affect upwelling and ocean currents in a number of ways.

Hydrothermal vents are underwater geysers that release hot, mineral-rich water into the ocean. The heat and chemicals released by these vents can create a unique ecosystem that supports a variety of marine life. The heat can also contribute to upwelling, which is the process by which deep, nutrient-rich water rises to the surface. This can have a significant impact on ocean currents, as upwelling can alter the temperature and salinity of the water, affecting the direction and strength of currents.

Lava flows, on the other hand, can create new land masses or alter existing ones, which can also have an impact on ocean currents. For example, the formation of new islands or the alteration of coastlines can affect the direction and strength of currents, as well as the distribution of nutrients and other materials in the water.

The ocean chemistry in these areas is also affected by the release of heat and minerals from hydrothermal vents and the alteration of land masses from lava flows. These changes can create unique chemical environments that support certain types of marine life and affect the overall chemical balance of the ocean in those regions.

Current terrestrial models do incorporate data and equations to reflect the impact of hydrothermal vents and lava flows on the biosphere. However, the extent to which these models incorporate data on deep ocean currents and the impact of underwater ecological regions on climate models may vary.

Climate model researchers do incorporate models of ecological regions underwater, as these regions can play a significant role in the overall climate system. However, there is still much to be learned about the complex interactions between deep ocean currents, underwater ecosystems, and climate change. Ongoing research and data collection are necessary to improve our understanding of these processes and incorporate them into climate models.

Hai KS

The effectiveness of teaching chemistry through elective courses depends on many factors, such as the quality and relevance of the course material and the qualifications and enthusiasm of the instructor. Some benefits of teaching through electives include engaging students in the subject, developing students' critical thinking skills, and encouraging independent learning. Disadvantages include unequal distribution of resources and an inability to keep up with the latest developments in the field. To ensure the success of elective courses in chemistry, it is necessary to have a clear scientific-pedagogical basis for their development. This basis should include a thorough introduction to the topics covered in the course and a discussion of their associated practical applications. It is also important to consider course goals and expectations, as well as students' prior knowledge and existing skills. Finally, it is important to create engaging and interactive activities that capture students' interest and motivate them to learn.

Extracción de colágeno sin perder las propiedades químicas. Cada método tiene ventajas y desventajas. Piensa que necesitas usar al menos dos métodos. Incluyo adjunto un artículo que compara una "solubilización" ácida y enzimática. Se incluyen varios métodos de caracterización.

Dear Janaki Devi Somasundaram

If you need use the software for organic chemical structures i advise https://biomodel.uah.es/en/DIY/JSME/draw.es.htm from Alcalá University, many times I used for draw and was really usefull, is free and you can use online don't need download.

Please see and possibly implement these:

One is using 5 or 10 % Pd on carbon to conduct hydrogenation of a number of functional groups in substances, then other factors are the solvent; the hydrogen pressure one provides to the Parr apparatus (and conduct the shaking in a constant way). One can calculate the amount but Pd/C is a catalyst which means that after reaction it will be present in almost quantitative way. I would advise to check the literature and take into account the amount of Pd/C which is reasonable. At the limit if you would use equal millimoles Pd/C and substrate, your reaction might not proceed quicker. In making 100 substances during my Ph.D I have always used say 50-100 mg for 20-25 g of substrate (I NEVER calculated millimoles). One reaction I recall is the conversion of 4-nitro-anthranilic acid to 4-amino-anthranilic acid with Pd/C in ethanol overnight at 3 bar hydrogen overnight.

What you are searching for is a so-called "cumulative doctoral thesis" [or in German "kumulative Promotion"]. There are some universities which offer it as an option, although I am not aware of any database on the issue.

If you have it as an option, it's probably a nice thing, but publications in general aren't plannable before your PhD work assuming you don't set a low bar for your research, so you must always stay ready to write a monography thesis.

In any case, I wouldn't recommend making that the top priority for choosing which group you join. The major criteria should be (a) that the topic is interesting enough for you to spend several yours of your life on it and (b) that the group you join is decently managed.

Vahid Rakhshan I will definitely spread the word about this amazing initiative. It's great to know that we can contribute to such a noble cause by simply utilizing our excess computer power. Thank you for bringing this opportunity to my attention. Let's join hands in making a difference in the fight against diseases.

I would not recommend to add [Ru(II)(bpy)3]2+ to your sample. Illumination of your sample with 454 nm light will result in an extremely complex photochemically initiated processes in your sample. In commercially available O2-sensors the sample is separated from [Ru(II)(bpy)3]2+ solution by a membrane. Such a sensor is a pretty complex device but not very expensive (several hundred US$).

Measuring the gel fraction is important in determining the monomer conversion in polymerization processes. The gel fraction is defined as the fraction of the polymerized material that has formed a three-dimensional network, which is insoluble in the solvent used for polymerization.

It is important to note that the gel fraction can be affected by various factors, such as the type and amount of initiator used, the temperature and pressure conditions, and the molecular weight of the polymer. Therefore, it is important to carefully control these variables and standardize the measurement procedure to ensure accurate and reproducible results.

you welcome

The reaction time and the temprature depends on the level of deacetylation that you would like to achieve. If you let your mixture react longer then the level of deacetylation will be higher.

You might need to experiment a bit till you get a product that has the desired characteristics. Or if you have a procedure for a product with the desired characteristics in the literature then you can simply follow that and get some good results.

Hi Wares,

This is very odd, and I have yet to experience such a problem. I guess that we are talking about point chirality where a carbon atom is a stereogenic center, and not axial or planar chirality? Could you share the molecule that you're talking about? Maybe that could give some insight into the issue.

Also, I would suggest you not to use molecular mechanics for the optimization (Avogadro offers only MM), but rather semiempirical methods or, even better, some DFT calculations. For semiempirical calculations, you could try ArgusLab software, it is free and fairly easy to use. It is getting a bit dated by now, but you'll get somewhat reasonable structures (for sure better than MM optimization). Also, MOPAC is a good software if you have some experience using it, but otherwise, I'd suggest using ArgusLab. However, DFT is the way to go if you need good structures. There are some free software packages (such as NWChem or GAMESS), and you could use Avogadro as a graphical interface.

Hope this helps.

May explode on heating

Applying the Addison parameter τ5 (a geometric parameter permitting the identification of the geometry around the central atom whether it is trigonal bipyramidal or square pyramidal) to describe the coordination polyhedron.

τ5 = (β-α)/60

where β and α are the two largest ligand–metal–ligand angles of the coordination sphere (τ = 0 for an ideal square pyramidal geometry and τ = 1 for an ideal trigonal bipyramidal geometry)

Refrences :

Hchicha, K., Korb, M., Badraoui, R., & Naïli, H. (2021). A novel sulfate-bridged binuclear copper (II) complex: Structure, optical, ADMET and in vivo approach in a murine model of bone metastasis. New Journal of Chemistry, 45(31), 13775-13784.

No, nitrogen in graphene cannot form covalent bonds through one of its lone pairs. Nitrogen atoms in graphene are typically incorporated as nitrogen doping and form pyridinic nitrogen, which only has one N-C bond, rather than covalent bonds.

Your cyclic peptide also includes a thiazole.

Check

The dry weight of the plant is determined based on the certain amounts of live/wet plant biomass and is variable (the physical, chemical and biomechanical processes are carried out in its content). The dry extract of the plant will undergo a physical phase change after the initial extraction based on a series of special post-processing in accordance with the relevant protocols.

Regards

Photoelectron circular dichroism (PECD) is a phenomenon that occurs when a molecule is irradiated with circularly polarized light, resulting in a difference in the yield of photoelectrons emitted from the molecule depending on the handedness of the circular polarization. PECD can be used to study the chiral properties of molecules, and is sensitive to the electronic and geometric structure of the molecule.

To calculate PECD using quantum chemistry, one can use a multi-reference configuration interaction (MRCI) approach, which is a method for treating electron correlation in molecules. MRCI calculations can be used to calculate the transition dipole moments for different electronic states, which are needed to calculate the PECD signal.

Another approach is time-dependent density functional theory (TD-DFT) which is a first-principle method to calculate PECD signal. TD-DFT can be used to calculate the transition dipole moments, and the PECD signal can be calculated by comparing the transition dipole moments for different electronic states.

It is important to note that the PECD signal is usually very small and difficult to measure experimentally and so it is important to use high level of theory and a good basis set to obtain accurate results.

You can do either of two things:

1. First, convert a Dowex cation exchanging resin, H+ form, to the desired ionic form by washing with 0.5-1M solution of a salt containing the desired cation followed by the extensive washing of the resin with water. Next, pass, at a slow flow rate, an aqueous solution of your nucleotide through a column containing min. 10-fold excess of the resin prepared as above and wash the column with several volumes of water to complete the elution of the nucleotide. Freeze-drying will give you your nucleotide in the desired ionic form.

2. If your nucleotide is retained on a C18 reverse phase column, you can dissolve the nucleotide in a solution containing the desired cation and apply the solution to the column. Next, wash the column with 3 volumes 0.1 M aqueous solution of the salt containing the desired cation. Next, wash the column with water, min 1 column volume. Finally, elute the nucleotide with 10-15% aq acetonitrile and evaporate the eluate to dryness. It would be advantageous to monitor the UV absorbance of all eluates by an on-line detector and collect only the UV-absorbing fractions. Not all nucleotides are retained by C18 reverse phase, particularly in the step of washing with water. If you decide to use this method make sure to check all eluted fractions.

In case you want to consider an acetic acid / sodium acetate buffer solution:

The pK_a of acetic acid is 4.75, from what we can only expect fair pH buffering effect between approx. 3.75 to 5.75. The pH of acetic acid / sodium acetate buffer solutions can be simply calculated based on the Henderson-Hasselbalch equation, after the molar concentrations of acetic acid (C_a) and sodium acetate salt (C_s) at the buffer solution: pH = pK_a + log10(C_s/C_a); what can be generally expected to hold for C_a > 100K_a. A possible derivation for this equation, along with a justification for the stated minimum concentration limit for its validity, can be found elsewhere at this forum: https://www.researchgate.net/post/pH_calculation_of_a_mixture_of_formic_acid_NaOH_and_water

I'm also concerned about this because the Nanopore's Barcode recognition often goes wrong

Hi, the starting material doesn't matter. I would use the unprotected amino acid (its way more cheaper), add dry methanol and at least 5 eq of TMSCl. Starting with an ice bath and after 30 min stirring raise to 40 °C for 2-3 h. Check the reaction progess via TLC. Good luck.

At lower pH, the adsorption backpedal by H+ ion factor or proton factor and at higher pH, adsorption hampered because of yhe metallic ions start to precipitate as metallic hydroxide or metallic oxide. So it is looking good the pH value near between 4-6, and you should have to study for optimum pH for the removal of particular metal like Cr.

On contrast, time mainly find out the breakthrough time for column study is not so easy like batch study. Here you need to conduct a lot of trial and also need to modeling of Thomas model, Adam-Bohart model, Yoon-Nelson model for the much more accurate BTC curve.

Thank you.

Dear Saifur Rahman Khan and Al,

lI wish you Happy New Year: success in your spiritual achievement, good health and prosperity for it!

I found the next on the facbook (https://www.facebook.com/USGSVolcanoes):

'A volcanologist is a person who studies volcanoes, but there are many different specialties within the field of volcanology. Which interests you and what steps should you take to achieve your goal? Find out more in #VolcanoWatch.

Earthquakes are one primary tool used to study volcanoes. A volcano seismologist studies the earthquakes that are generated as magma moves through Earth’s crust.

A volcano geodesist studies the deformation, or change in shape, of a volcano caused by the movement of magma and gases beneath the surface. Many features of volcanoes can be studied from space, as well, using satellite sensors. Tools like these provide clues about the state of the volcano.

Geologists and geochemists study the composition of lavas and gases to understand the source and style of the eruption. Measuring gas emissions is especially important, as the vog (volcanic air pollution) caused by toxic volcanic gases can contribute to breathing problems, acid rain, and agricultural problems downwind, especially during long-lived eruptions.

If you are interested in becoming a volcanologist, you’ll need to work toward a bachelor’s degree, preferably in a STEM field (Science, Technology, Engineering, and Math). Volcanologists frequently pursue degrees in geology, chemistry, physics, and/or mathematics, but that is not always the case. Oceanography, computer science, engineering, environmental science are all potential pathways, and the list goes on. Explore different fields to find what interests you most.

After achieving a bachelor’s degree, consider options for advanced degrees like a Masters or Doctorate. Many advanced degree programs in the sciences are funded, meaning tuition may be waived, and you might get a stipend for doing the work. Basically, you get paid instead of having to pay for school, and you gain valuable work experience at the same time.

You might consider working for the USGS or other agencies and companies. You have seen many photos of HVO scientists working during the eruptions of Mauna Loa and Kīlauea. The National Park Service also offers a variety of positions for people with either bachelor’s or advanced degrees, such as park geologists, archaeologists, botanists, guides, interpretive rangers, and law enforcement rangers. Science writing and journalism are also excellent ways to explore the excitement of volcanology, natural disasters, and cutting-edge science, while encouraging those passions in others. Similarly, eco- and geo-tourism are great ways to get close to the action and work outdoors, while also meeting, educating, and inspiring people from all over the world. Careers in emergency management will have you helping people stay informed during crises.

Check out usajobs.gov for positions within the federal government. There is even a special section for students and recent grads.

Volcano Activity Updates

#MaunaLoa is not erupting. Webcam imagery shows weak, residual incandescence intermittently in the inactive Northeast Rift Zone fissure 3 lava flow at night. Seismicity remains low and ground deformation rates have decreased. Sulfur dioxide (SO2) emission rates are at background levels. For Mauna Loa monitoring data, see: https://www.usgs.gov/volcanoes/mauna-loa/monitoring-data.

#Kilauea is not erupting. Lava supply to the Halemaʻumaʻu lava lake in Hawai‘i Volcanoes National Park ceased on December 9. Sulfur dioxide emission rates have decreased to near pre-eruption background levels and were last measured at approximately 200 tonnes per day (t/d) on December 14. Seismicity is elevated but stable, with few earthquakes. Over the past week, summit tiltmeters recorded several deflation-inflation (DI) events. For Kīlauea monitoring data, see https://www.usgs.gov/.../past-week-monitoring-data-kilauea.

There were three earthquakes with 3 or more felt reports in the Hawaiian Islands during the past week: a M3.3 earthquake 14 km (8 mi) S of Fern Forest at 7 km (4 mi) depth on Dec. 27 at 4:33 a.m. HST, a M3.4 earthquake 7 km (4 mi) WSW of Volcano at 2 km (1 mi) depth on Dec. 24 at 8:31 p.m. HST, and a M2.5 earthquake 1 km (0 mi) S of Mountain View at 11 km (7 mi) depth on Dec. 24 at 9:57 a.m. HST.

In the photo, an HVO technician adjusts a volcanic gas analysis instrument that was specifically designed for this Unoccupied Aircraft System (UAS) unit, which carries three one-liter analysis bags. The instrument transmits gas concentration information in real-time during the flight at Kīlauea summit. USGS has special use permits from the National Park Service to conduct official UAS missions as part of HVO's mission to monitor active volcanoes in Hawaii, assess their hazards, issue warnings, and advance scientific understanding to reduce impacts of volcanic eruptions. Launching, landing, or operating an unoccupied aircraft from or on lands and waters administered by the National Park Service within the boundaries of Hawai‘i Volcanoes National Park is prohibited under 36 CFR § 1.5 - Closures and public use limits.

USGS image taken January 14, 2022 by M. Warren.

#USGS #HVO #HawaiianVolcanoObservatory'

Maybe it can help you!

Regards,

Laszlo

It is not uncommon for certain lab supplies to be in high demand or backordered due to various reasons such as an increase in demand for certain types of research or supply chain disruptions. In such cases, it may be helpful to try reaching out to the manufacturer or distributor directly to see if they can provide any information on when the vials will be back in stock. Additionally, you can try looking for alternative suppliers or checking with local scientific supply companies to see if they have any borosilicate glass vials in stock.

Alternatively, you could consider using other types of containers for storing and drying your tissue samples. For example, you could use pre-combusted aluminum foil packets as you mentioned, or you could try using pre-combusted tin capsules or pre-combusted glass vials. It is important to ensure that the containers you use are properly combusted and clean to avoid contamination of your samples.

It is also worth noting that the type of container you use may depend on the specific requirements of your stable isotope analysis method. It is always a good idea to consult with your laboratory or the manufacturer of the stable isotope analysis equipment to ensure that the container you choose is suitable for your specific application.

To reach the Scopus document search module, you should use academic IPs. If your institute has been listed in the Scopus database, you have permission to search documents in Scopus. It is not free of charge, and your university should pay its share to Scopus to provide this service for its academic researchers.

Bar Friedman

We have a substance. We study it using physical methods and determine that its molecules have a dipole moment , they are polarized under the action of an external electromagnetic field ... We determine the structure of the molecule. We compare with other molecules and come to the conclusion that in some molecules the electron density shifts under the action of a magnetic field along a chain of sigma bonds (inductive effect). For other molecules, the electron density shifts along the chain of pi bonds (resonant effect). Bonds between atoms in molecules are primary, while inductive and resonant effects are secondary.

As you mentioned it. The gas phase in VASP may be incorrect. An easy way to do the solid phase and gas phase could be:

1. Solid phase: compute the vibrational frequencies of the system. With that, you could calculate the enthalpy=U+KbT+H_vib., and then the Gibss as H-TS ( )

2. Gas phase: You could follow the tutorial of ORCA (free software: https://www.orcasoftware.de/tutorials_orca/prop/thermo.html). You must construct a good (and representative) model of your system in gas phase.

alcohols like methanol and ethanol are the best solvents to extract phenolic compounds. but these can also be extracted with water but it depends on the part of the plant drug used (leaves, flowers, roots ........) you must also do a bibliographic research on the optimization of the various extracts used on your plant in order to obtain the best yield in polyphenols. good luck

Dear Pablo Reguera ,

In short it is basically as said here by the Sigma-Aldrich site (https://www.sigmaaldrich.com/NL/en/product/sial/f9252) “Addition of the phenol reagent generates chromogens that give increasing absorbance between 550-750nm. Normally, absorbance at the peak (750nm) or shoulder (660nm) are used to quantitate protein concentrations between 1-100 mg/ml while absorbance at 550nm is used to quantitate higher protein concentrations.”.

Or as said in one of the most cited papers when it comes to Folin–Ciocâlteu reagent (FCR) “Because of the breadth of these peaks and the fact that other components in biological samples do not absorb in this region, analysis can be carried out at a wide range of wavelengths, 760 nm generally being chosen for FC.” (Analysis of total phenols and other oxidation substrates and antioxidants by means of folin-ciocalteu reagent).

See for what they mean by breadth for example the absorbance spectra in the following paper (Figure 1): https://www.researchgate.net/publication/237096981_Application_and_Analysis_of_the_Folin_Ciocalteu_Method_for_the_Determination_of_the_Total_Phenolic_Content_from_Limonium_Brasiliense_L

Although the overall message is that every wavelength between 750-765 nm is fine, personally, I would go for 765 nm. This is based on the official JAOAC method: https://academic.oup.com/jaoac/article/102/1/320/5658204 but as said every wavelength is fine as long as you clearly indicate in your method which wavelength you choose (and on which paper you based that choice).

Best regards.

You may also see the retrosynthesis pathway from scifinder

Koç university, Sabancı university (more suitable for interdisciplinary subjects), Boğaziçi university and METU.

Interesting situation. As soon as I write a question here, I immediately find the answer. Here are some papers on pharmaceutical salts (responding to my comment above): 1) 10.1016/j.ijpharm.2021.120993; 2) 10.1016/j.jddst.2021.102913

Hi Ioan, Gaussview can help you.

Best wishes,

Quang

origin

Formic Acid maybe. It is used in LC-MS.

Hello,

in order to determine ammonium, i find that the Nessler method of determining ammonium should be suitable for you. As suggested in Paul Milham's answer, it is a colorimetric assay. It has the advantage of being easy to perform (no need to heat, for urine there should be no need to correct the pH and the reaction is fast) and sensitive. Don't hesitate to ask if you have any questions. Good luck.

Clarivate announced that starting with 2023 ESCI-indexed journals will also be assigned an impact factor. See: https://clarivate.com/blog/clarivate-announces-changes-to-the-2023-journal-citation-reports-release/

It would depend on the jurisdiction because patents are national rights as are utility models. Many countries don't have utility models and there are some which have what are called "petty patents" which are like utility models. I am only qualified to advise on UK law (and it would be a criminal offense under the UK Patent Act to mark a product so as to claim to have a UK patent if you didn't have a UK patent), but the rule of thumb for every jurisdiction must be to act honestly and reasonably. So if you have a German Utility Model then say you have a German Utility Model, if you have an Indian Patent Application, then claim you have an Indian Patent Application, etc etc

When I was looking into data augmentation techniques, I came across SMILES enumeration for molecules.