How to find a correlation between coordinates in a curvilinear coordinate system?

Hello. I have a skewed elliptical coordinate system (I use alternative elliptical coordinates). And I need to determine connections between coordinates in order to fetch a covariance matrix of...

28 February 2021 364 3 View

Failed Chromatograms on HPLC-ESI Orbitrap?

Hello fellow researchers, I recently have a problem with an HPLC coupled to an Orbitrap mass analyzer. I usually use some protein mix to make sure the equipment is ready to separate and read...

09 February 2021 3,595 8 View

PEG coated Fe3O4 nanoparticles in aqueous NH3?

Hello, I synthesized PEG coated Fe3O4 nanoparticles by coprecipitation methods and I would like to ask whether they can be dispersed in aqueous NH3 since they have a PEG coating and theoretically...

06 February 2021 5,217 4 View

Is there such a function? Is it unique?

21 January 2021 8,962 13 View

What are the current developments in terms research and publications in anthropology in general and social anthropology in particular?

I am interested in examples of anthropological methods that have been applied across different disciplines, for exmple in mathematics education.

20 January 2021 3,090 3 View

How did the tests or exams get to Latin America, specifically the written tests?

I am looking for some bibliographic references that explain how tests or exams (measurement and assessment in education) came to Latin America, specifically written tests. I would like to know if...

13 January 2021 8,607 0 View

Do you know any available open-source data on animal behavior for model validation?

In my research related to monitoring the cow behavior with help of sensors I have a permanent and principal problem with the data for model validation. I tried to find some available open-source...

26 December 2020 8,197 2 View

Is this true for all values c > 0?

25 December 2020 3,621 45 View

Can children from 1 year old to 15 years be given MODANA and Pfizer Anti-COVID-19 vaccine?

The clinical disease of COVID-19 has been low in children generally and vaccine has been develop.Any evidence of its safety,efficacy and risk for allergy in children? any exemption for children...

23 December 2020 7,177 12 View

Can large samples be stored at -20 degrees prior to RNA extraction?

As part of a Covid project we are sampling urban rodents and performing RNA extractions and serology work. We have too many samples to store at -80 and have opted to perform extractions the same...

15 December 2020 5,252 2 View

Resistor definition in Piezoelectric bimorph with ANSYS workbench

Hello, good day! I am trying to simulate similar bimorph piezoelectric harvester with below commands. However, the output power doesn't change with resistor value. Please help to find the reason. ET,10,CIRCU94,0 !SET UP RESISTOR R,1,100000 !RESISTANCE VALUE TYPE,10 !SET ELEMENT TYPE E,1,2 !CREATE RESISTOR BETWEEN NODES 1 AND 2 Thanks in advance Regards,

02 March 2021 0 0 View

Waters 2707 HPLC autosampler problem?

I am using a 2707 waters HPLC device. When I try to inject a sample, it says missing plate or rack. I changed the needle and calibrated its position but I still get the same problem. I even get...

02 March 2021 1,408 1 View

How optimize the Size Exclusion Chromatography?

Hello! I'll do a size exclusion chromatography, but I only have an open column, and I'll perform the peptide extraction from yeast, using buffer lysis (sodium phosphate 50 mM/NaCl 30 mM/DNAse and...

01 March 2021 2,215 2 View

No title

01 March 2021 3,905 5 View

What test should I use to compare two or three means, if data is not normally distributed but sample size is > 30 in each group?

I personally feel this as a most confusing question. As per my understanding, if sample size is > 30, and sample is skewed, we can still use paramteric approach, as it will follow Z...

01 March 2021 1,587 6 View

Precipitate after adding laemmli buffer to protein solution containing Potassium Acetate?

Hi, I am running a size exclusion chromatography experiment with a buffer containing Potassium Acetate as a salt. I analyse these fractions through SDS-PAGE. After boiling my SEC fractions in...

01 March 2021 2,622 3 View

Any research papers for extraction of nutrient deprivation on macroalgae? Analysed by HPLC-UV and GC/MS. Possibly from macroalgae genus Rhizoclonium?

I am doing my thesis on the nutrient deprivation on the macroalgae Rhizoclonium sp. I will be analysing the levels over a period of roughly 5 days by HPLC-UV and GC/MS. I will be using seawater as...

28 February 2021 6,477 1 View

How to define tie constraint between rigid body and another part in dynamic explicit model of Abaqus?

Hi dear researchers I connected a rigid body into the part of my structure by tie constraint and then I added displacement to rigid body, in static general step every thing is fine and these two...

28 February 2021 3,442 2 View

Sample size determination for non-parametric tests?

How do I run a a priori sample size determination for non-parametric tests, like the Mann-Whitney U-test and the Kruskall-Wallis or other non-parametric tests that accord with the unpaired t-test...

24 February 2021 166 6 View

Do you kow of any database containing data on retention time, log P and polarizability for a large number of molecules?

Hi, I am a chemistry undergraduate doing my dissertation project on HPLC. In my project, I need to predict the HPLC retention time of 20 aromatic molecules, the calibration set. To do this I will...

24 February 2021 2,602 1 View