Color of spiro-ometad film?

What does the color of a spiro-ometad film indicate? I got purple, green, red, even black color of the spiro film. Is there anything we can get from the preliminary color analysis(e.g. oxidation...

21 February 2021 1,831 4 View

Dissolving AN-MA-IA copolymer in 50 % w/w sodium thiocyanate water solution. What is the white residue forming after polymer dissolved?

Dear colleagues! Recently I tried to dissolve commercially available samples of PAN precursors (acrylonitrile-methyl acrylate-itaconic acid terpolymers) in water solutions of sodium thiocyanate...

17 October 2020 6,083 4 View

What is the reason of poor resolution of AFM images of TiO2?

We prepare TiO2 samples using Titanium Isopropoxide, Ethanol, and Glacial Acid; We increase the amount of ethanol to decrease the thickness of the layer. However, the layers with thicknesses...

30 August 2020 4,031 13 View

Band in the negative control of qPCR product gel?

I persistently get a band in the negative control when trying to isolate RNA from cell samples and am wondering if it's contamination in the experiment, genomic contamination, or just the...

02 August 2020 6,486 1 View

If G is a tree, then L(G)D(G)L(G)=-2L(G). Is the opposite true?

It is well known that if graph G is a tree, then the following identity holds: LDL=-2L, where L is the Laplacian matrix of tree G, and D is its distance matrix. Is the opposite true? That is, if...

28 May 2020 4,298 3 View

Miocene green algae in thin sections?

Dear colleagues In attached photos, you will find green algae (?) from the Miocene glendonite-bearing rocks of Sakhalin (SEM photos of thin sections) Is anybody can help with identification of...

02 January 2020 4,041 3 View

Why images in scanning electron microscope(sem) got bright stripes?

why images in scanning electron microscope(sem) got bright stripes? an image is attached. it does not look like a material related contrast(polymers). it does not disappear with current, voltage...

02 January 2020 2,404 4 View

How to model Background Seismicity in EZ FRISK?

does anybody know how to model background seismicity in EZ FRISK 7.65? I understand we have to define it as grid source, but I don't quite understand the input parameter required, it requires...

03 September 2019 819 1 View

Could you recommend some papers where two CMIP5 experiemnts are compared: historical and pre-industrial control runs?

I am interested not in the technical description but in the case studies, e.g., when the variability of various fluxes is studied.

12 June 2019 3,088 2 View

Wrong ethanol IR spectra?

I've measured three different ethanol samples in my IR spectrometer, whose spectra are attached (one in absorbance and another in transmittance units). The measurement was made with liquid ethanol...

08 May 2019 5,677 9 View

Blast analysis of RC,UHPC slabs using material model *MAT_72R3 in LS-DYNA?

20 February 2021 5,984 3 View

Do you have any suggestions for me to modify my LS-DYNA model?

Hi, I use LS-DYNA to simulate the steel composite shear wall now. I use MAT_084/085 to simulate concrete, MAT_159 to simulate steel plates, and MAT_024 to simulate studs. The concrete section...

24 January 2021 3,863 1 View

I am trying to run a simulation on LS-Dyna and I am facing the error below with Nodal rigid constraints. Can anyone tell how to fix it?

*** Error 20393 (STR+393) Nodal rigid body ID 85000010 contains node ID 83500180 already used in a rigid body/nodal rigid body definition.

20 January 2021 2,019 1 View

Why does the impact force of barge pier collision suddenly increase to the peak value in finite element simulation?

I am learning the knowledge about barge pier collision these days, and have a problem that the impact force of barge pier collision suddenly increase to the peak value in ls-dyna. But the...

05 December 2020 9,978 3 View

Extracting Stiffness Matrix From LS-Dyna?

Hello, I am actually trying to optimize an armour plate for now. For this purpose, I need the stiffness matrix of the plate. While I can write a Matlab code to compute this it will be hard to...

02 November 2020 7,213 3 View

How to model deformable metal powder?? How to define gap between the particles?? Which modeling software can be used??

We need to model deformable metal powder. It will be further used in simulation process.

30 September 2020 9,329 7 View

How can I define 2 inlet and 2 output segment for X shaped Copper Conductor with same Applied Voltage ?

Hi, I am working on a diamond shaped Copper Conductor using LS Dyna EM Multiphysics Solver. I am able to run when I have a simple one inlet and one outlet (pic of results attached for a unit...

12 September 2020 2,877 1 View

Discrete Element Method Simulation Example Using Ls-Dyna?

I am interested to simulate the fracture process of glass using DEM in Ls-Dyna and need some example or bench mark case for learning.

21 July 2020 4,156 2 View

How can I model a simple plate-sphere impact in LS-Dyna as symmetry quarter model?

I want to model an impact simulation of the sphere at the center of a solid plate. How can I model it as quarter symmetry model? Full model snapshot attached.

20 July 2020 2,221 1 View

How to simulate dynamic problem with large process time almost 60 sec?

Dears i am trying to simulate friction stir spot welding process, it is process very similar to drilling process but with different tool, i need to know the effect of process time on the heat...

13 June 2020 1,052 3 View