Has anyone done any work on the cosmogenesis of the heavier atmospheric isotopes of 18O and 15N?

03 July 2025 0 3K Report

The data record suggests that this process is higher than thought during X Class flares, but this seems to be an area of research not yet covered.

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Dear colegues, someone has MELO (1996) Manual de identificacao dos brachyura (caranguejos e siris) do litoral brasileiro?

After looking in Google Scholar, BHL and several repositories I hope someone could have a pfd copy of the MELO (1996). Melo, G. A. S. (1996). Manual de identificacao dos brachyura (caranguejos e...

21 May 2024 492 0 View

How does my new Research Associate sign up for accesss to ResearchGate?

I have long been a member of ResearchGate. I have a new Research Associate. She has been trying to sign up through the website, but has been unable to gain access. How do we get her signed up...

21 April 2024 1,895 6 View

Do I have permission to cite and include photos in papers that I author?

Paper concern the Yucca Mountain Nuclear Waste Repository project and the Waste Isolation Pilot Project.

09 April 2024 746 4 View

How does cell supernatant affect enzyme assays using pnpp substrates?

For enzyme assays using cell supernatant which are slight yellow and using pnpp substrate which will also produce the yellow pnp substrate will predictably have a distortion on the absorbance. to...

02 March 2024 5,149 3 View

Why does the absorbance for my enzyme assay increase then decrease?

Hi, I am measuring the production of 4nitrophenol at 405nm for my enzyme assay. In the neg control (buffer + substrate) and the enzyme reaction at pH 5.5, 6.5 I observe the absorbance initially...

09 December 2023 1,091 4 View

Preparation of 3-(Trifluoromethyl)-3phenyldiazirine using methanolic ammonia or anhydrous liquid ammonia?

Hi everyone, I would like to ask that if the reaction can be used with ammonia solution in methanol (7N), because in my place is hard to get pure anhydrous ammonia. I have seen an article that...

27 August 2023 7,830 0 View

Multiple Finance models in a single research, is it a feasible aspect or an epistemological error?

Is it possible to run Sharpe s Index, Value at Risk ( historical model or minte carlo model) and Monte carlo simulation simultaneously on the same data set to get a detailed understanding on the...

21 August 2023 4,774 3 View

Wave optics module and time domain with Comsol?

I am developing a 2D photonic crystal resonator and would like help from colleagues to configure the propagation of electromagnetic waves in the time domain using the wave optics module....

30 July 2023 2,592 2 View

Do the methyl branch on a propylene carbonate have a greater surface tension reduction effect than ethylene carboante?

Surfactants with branched chains are known to reduce surface tension more than linear chain. However to what effect does a methyl branch on a propylene carbonate have compared to ethylene carbonate?

14 July 2023 1,678 0 View

Photonic crystal device with comsol?

which "study", from comsol, to use to calculate the transmission spectrum of 2D photonic crystal device? And how to configure it? Basically the device is a crystaline network of silicon rods...

02 July 2023 5,728 2 View

Collecting/storing plant stable isotope samples?

Hello! I am planning to collect plant leaf samples for stable isotope analysis. I will be collecting them from the field and storing fresh tissue on ice. I have heard that bringing along a food...

01 July 2024 9,125 1 View

How to properly label fish feed pellets with stable isotopes for tracing C and N flow?

Hi, I´d like to trace the C and N flow in a recirculating aquaculture system by labelling the fish feed with concentrated stable isotopes. From a supplier, I found a product ouf of algae lysate...

19 June 2024 746 0 View

How do I calculate endogenous peptide using Isotope Dilution Mass Spectrometry (IDMS)?

Dear Researchers, I'm trying to develop the quantification of endogenous peptide in tissue using IDMS as the primary method of characterization. I performed analysis for the calibration curve of...

17 June 2024 9,797 0 View

How to distinguish the origin of sulfides in subduction zone interface rocks?

If we find sulfides in subduction zone interface rocks, how can we distinguish whether these sulfides are related to crust-derived fluids or originate from the original mantle wedge? Especially...

15 June 2024 654 1 View

Does the zirconium isotope fractionate as through the column?

Is the zirconium isotope of geological sample fractionated when passing through the column, and how to determine whether this fractionation is or not？

26 May 2024 6,721 2 View

What type of natural sample should be targeted to make secondary reference material for oxygen isotope analysis?

What kind of rock should be targeted to prepare secondary oxygen isotope standard? The mineral of interest is quartz.

27 April 2024 6,251 2 View

Why am I getting low isotopic enrichment in my expressed protein even though I am using labeled media?

I am expressing a membrane protein (about 15 kDa) in BL21(DE3) cells. The expression is good, and the yield is decent, but each time I checked the mass with a TOF mass spec, the mass I get is...

11 April 2024 7,169 3 View

How should I interpret the points which plot above the LMWL on the d2H vs d18O bivariate plot?

So, I am unsure how I should interpret the situation when the majority (let’s suppose 3/4) of my data aligns above the LMWL, while a smaller part (suppose 1/4) aligns below the LMWL. I conduct...

03 April 2024 1,958 0 View

Can anyone help me to find relevant lab to measure Mg isotope in soil and water?

I will plan to measure Magnesium isotope in water and soil. Can anyone help me to find a relevant lab to measure Mg isotope and their sample requirement (sample quantity, preservative techniques,...

25 March 2024 1,216 1 View

Is it possible to know the dwell time for a given isotope/mass from a raw LA-ICP-MS trace elements data file?

I have a dataset of trace elements LA-ICP-MS analyses with raw data, which consists of a set of a single file for each spot analysis. Each of these files has some columns (masses) and plenty of...

24 March 2024 898 6 View