Anyone with experience in high frequency OAE testing and calibration?

More Lucretia Petersen's questions See All

What is a good method to select variables for Cox Regression?

Dear biostats community, I am trying to build a Cox (Proportional Hazards) Regression and have a dataset with several variables. I am trying to decide which variables are the most useful to use...

09 April 2022 5,875 2 View

What effects does the zero-interest policy have on risk taking behavior of private investors, especially large ones who can afford high losses?

What effects does the zero-interest and negative-interest policy of the central banks have on the willingness to take risks of private investors in venture capital and private equity firms,...

30 January 2022 1,124 6 View

Are the venture capital and private equity firms a new vehicle to trigger a future financial crisis?

Shadow banks, which played a key role in triggering the recent global financial crisis, and venture capital companies that followed, have partly displaced traditional banks from corporate...

30 January 2022 6,333 8 View

How do I manage sibling observations of nutritional status of children in a regression analysis?

I have data from households, where two types of data were collected: A validated questionnaire (Household Dietary Diversity Score (HDDS)), which gives a score between 0 and 12 for each...

17 August 2021 9,577 3 View

Time dilation in the early universe?

Something which has always bugged me about the standard model is how can we approximate the age of the universe, when at the beginning, the incredible density would dilate time to the point to...

15 June 2021 9,631 51 View

How do you create a batch report in Agilent Chemstation version B04.02 while applying an internal standard?

I have an old version of Chemstation B.04.02 for GC and HPLC systems. I am able to create a batch report of my results with a calibration curve, however, I also have an internal standard. I have...

25 April 2021 8,065 1 View

Why is my Shimadzu Tvcsh-tnm yielding different total nitrogen results when internal sparging is on and off?

My Shimadzu TOC/TN analyzer is yielding inconsistent total dissolved nitrogen results for samples, but not standards and is likely due to sparging. The samples are all filtered and the instrument...

19 April 2021 9,690 4 View

What are some common oxidants used to oxidize iron sulfur clusters in proteins for techniques like EPR?

I have used potassium ferricyanide (which is likely the most common) extensively in the past, but I am curious to know if there are other oxidants that work well. I need to generate the oxidized...

29 January 2021 10,087 4 View

Which litter bag fabric is recommended for 10 year decomposition experiment in peat soil?

Which litter bag fabric (the fabric of the bag itself, not the litter material) would you recommend for a decomposition experiment in which litter bags will be buried in wetland peat soils for up...

30 April 2020 3,534 0 View

How can I test for categorical trait correlation/coevolution given a phylogeny?

I have a phylogeny and two categorical traits (one binary, one multi-state) mapped to its tips. My claim is that there is a correlation in their phylogenetic distribution, i.e. that they evolved...

10 February 2020 10,121 7 View

Which type of compound does lamda max of 218 indicate in a uv-vis spectrum of a partially purified compound through column and TLC?

A crude extract of fungal culture using EtOH was subjected to column and TLC and partially purified compound was obtained. UV vis spectrum of the compound/s has max absorbance at 218nm. The...

11 August 2024 9,801 2 View

Can you connect an HPLC to a Mass Spec only at a certain time point?

Can anyone explain this method? Especially the last statement where it says only at 1.5 to 2.5mins was the MS/MS connected to the UPLC. How is that possible, is it a feature in this specific...

11 August 2024 8,141 3 View

GC-MS retention index prediticon?

Hello experts, Does anyone know any free software about retention index prediction ?

08 August 2024 7,403 2 View

Can I use a HisTRAP column for affinity chromatography?

I'm working on selecting antibodies against a recombinant protein that has a His-tag. My idea is to first bind the recombinant protein to a HisTRAP column and then use this column for an affinity...

07 August 2024 505 3 View

Why does my protein refolded to beta sheet during thermal denaturation analysis?

Hi! So i attempted to understand a novel protein behavior towards heat application by analyzing its secondary structure change. I subjected the protein to a thermal denaturation analysis using...

06 August 2024 1,989 3 View

Why is electronic energy 0.000 for liquid crystal compounds and is invariable with temperature in Guassian 09 software?

Are there any suggestions or insights you can provide to help address this problem

06 August 2024 1,443 2 View

Why is TLC not a form of partition chromatography?

Why is TLC not a form of partition chromatography and paper chromatography not a form of absorption chromatography?

03 August 2024 7,035 3 View

Is there any Indian Company or Startups, from any universiy or IITS, which manufacture Gas Chromatography instrument , i want to make a custOmized G?

or we can collaborate

01 August 2024 6,705 2 View

Is there a good freeware software for photodocumentation of TLC?

I need something like Camag's VisionCat software for photodocumentation of TLCs. Could you recommend something?

31 July 2024 8,415 1 View

Transfection in HEK293T cells?

Dear All, I am trying to transfect a pCDNA3.1 vector containing my gene of interest. The purpose is to figure out the localization of the protein of interest. I have fused the protein with GFP on...

31 July 2024 9,892 4 View