Determination of material properties and failure using in-situ thermo-mechanical probe

Author(s):  
B. Arrazat ◽  
S. Orellana ◽  
C. Rivero ◽  
P. Fornara ◽  
A. Di-Giacomo ◽  
...  
1998 ◽  
Vol 120 (2) ◽  
pp. 188-194 ◽  
Author(s):  
B. R. Simon ◽  
M. V. Kaufmann ◽  
M. A. McAfee ◽  
A. L. Baldwin ◽  
L. M. Wilson

A “porohyperelastic” (PHE) material model is described and the theoretical frame-work presented that allows identification of the necessary material properties functions for soft arterial tissues. A generalized Fung form is proposed for the PHE constitutive law in which the two fundamental Lagrangian material properties are the effective strain energy density function, We, and the hydraulic permeability, k˜ij. The PHE model is based on isotropic forms using We=Ue(φ)=1/2C0(eφ−1) and the radial component of permeability, k˜RR=k˜RR(φ), with φ=C′1(I¯1−3)+C′2(I¯2−3)+K′(J−1)2. The methods for determination of these material properties are illustrated using experimental data from in situ rabbit aortas. Three experiments are described to determine parameters in Ue and k˜RR for the intima and media of the aortas, i.e., (1) undrained tests to determine C0, C′1, and C′2 (2) drained tests to determine K′; and (3) steady-state pressurization tests of intact and de-endothelialized vessels to determine intimal and medial permeability (adventitia removed in these models). Data-reduction procedures are presented that allow determination of k˜RR for the intima and media and Ue for the media using experimental data. The effectiveness and accuracy of these procedures are studied using input “data” from finite element models generated with the ABAQUS program. The isotropic theory and data-reduction methods give good approximations for the PHE properties of in situ aortas. These methods can be extended to include arterial tissue remodeling and anisotropic behavior when appropriate experimental data are available.


2003 ◽  
Vol 791 ◽  
Author(s):  
Vladimir P. Oleshko ◽  
James M. Howe

ABSTRACTQuantized high-frequency (∼1016 Hz) correlated longitudinal electron excitations (plasmons) generated in the energy-loss range 0–50 eV by fast electrons passing through any solid enable one to probe various states of matter. Their energy, Ep, is directly related to the density of valence electrons, thus allowing determination of solid-state properties that are governed by ground-state densities. Universal features and scaling in relations between Ep and the cohesive energy per atomic volume, bonding electron density and elastic constants have been established. The resulting correlations follow the universal binding energy relationship, thus providing new insights into the fundamental nature of structure-property relationships. They allow direct in situ determination of local material properties in an analytical electron microscope, as illustrated by examples utilizing Al- and Ti-based structural alloys.


1961 ◽  
Vol 38 (4) ◽  
pp. 545-562 ◽  
Author(s):  
L. Kecskés ◽  
F. Mutschler ◽  
I. Glós ◽  
E. Thán ◽  
I. Farkas ◽  
...  

ABSTRACT 1. An indirect paperchromatographic method is described for separating urinary oestrogens; this consists of the following steps: acidic hydrolysis, extraction with ether, dissociation of phenol-fractions with partition between the solvents. Previous purification of phenol fraction with the aid of paperchromatography. The elution of oestrogen containing fractions is followed by acetylation. Oestrogen acetate is isolated by re-chromatography. The chromatogram was developed after hydrolysis of the oestrogens 'in situ' on the paper. The quantity of oestrogens was determined indirectly, by means of an iron-reaction, after the elution of the iron content of the oestrogen spot, which was developed by the Jellinek-reaction. 2. The method described above is satisfactory for determining urinary oestrogen, 17β-oestradiol and oestriol, but could include 16-epioestriol and other oestrogenic metabolites. 3. The sensitivity of the method is 1.3–1.6 μg/24 hours. 4. The quantitative and qualitative determination of urinary oestrogens with the above mentioned method was performed in 50 pregnant and 9 non pregnant women, and also in 2 patients with granulosa cell tumour.


2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.


2020 ◽  
Author(s):  
Satoshi Morooka ◽  
Nobuo Nakada ◽  
Yuhki Tsukada ◽  
Wu Gong ◽  
Takuro Kawasaki ◽  
...  

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