scholarly journals The variations of wear readings study according to EN 295-3 method using the ISO 6133 standard for analysis of multi-peak curves

2021 ◽  
pp. 7-9
Author(s):  
V. V. Kovriga ◽  
L. G. Kurmanina ◽  
V. V. Sevastyanov ◽  
V. R. Gumen

It is shown that the set of data on the loss of wall thickness when determining the magnitude of hydroabrasive wear is a multipeak curve. An attempt was made to determine the amount of wear in accordance with the requirements of ISO 6133 "Analysis of multipeak traces". It has been shown that this treatment reveals higher wear values than those applied according to EN 295-3.

1996 ◽  
Vol 35 (05) ◽  
pp. 146-152 ◽  
Author(s):  
A. Kögler ◽  
H.-A. Schmitt ◽  
D. Emrich ◽  
H. Kreuzer ◽  
D. L. Munz ◽  
...  

SummaryThis prospective study assessed myocardial viability in 30 patients with coronary heart disease and persistent defects despite reinjection on TI-201 single-photon computed tomography (SPECT). In each patient, three observers graded TI-201 uptake in 7 left ventricular wall segments. Gradient-echo magnetic resonance imaging in the region of the persistent defect generated 12 to 16 short axis views representing a cardiac cycle. A total of 120 segments were analyzed. Mean end-diastolic wall thickness and systolic wall thickening (± SD) was 11.5 ± 2.7 mm and 5.8 ± 3.9 mm in 48 segments with normal TI-201 uptake, 10.1 ± 3.4 mm and 3.7 ± 3.1 mm in 31 with reversible lesions, 11.3 ± 2.8 mm and 3.3 ± 1.9 mm in 10 with mild persistent defects, 9.2 ± 2.9 mm and 3.2 ±2.2 mm in 15 with moderate persistent defects, 5.8 ± 1.7 mm and 1.3 ± 1.4 mm in 16 with severe persistent defects, respectively. Significant differences in mean end-diastolic wall thickness (p <0.0005) and systolic wall thickening (p <0.005) were found only between segments with severe persistent defects and all other groups, but not among the other groups. On follow-up in 11 patients after revascularization, 6 segments with mild-to-moderate persistent defects showed improvement in mean systolic wall thickening that was not seen in 6 other segments with severe persistent defects. These data indicate that most myocardial segments with mild and moderate persistent TI-201 defects after reinjection still contain viable tissue. Segments with severe persistent defects, however, represent predominantly nonviable myocardium without contractile function.


1995 ◽  
Vol 32 (3) ◽  
pp. 453
Author(s):  
Sung Hoon Chung ◽  
Hyun Sook Kim ◽  
In Oak Ahn ◽  
Goo Lee ◽  
Joon Hee Joh

Author(s):  
Deepak D. ◽  
Nitesh Kumar ◽  
Shreyas P. Shetty ◽  
Saurabh Jain ◽  
Manoj Bhat

The expensive nature of currently used materials in the soft robotic industry demands the consideration of alternative materials for fabrication. This work investigates the performance of RTV-2 grade silicone rubber for fabrication of a soft actuator. Initially, a cylindrical actuator is fabricated using this material and its performance is experimentally assessed for different pressures. Further, parametric variations of the effect of wall thickness and inflation pressure are studied by numerical methods. Results show that, both wall thickness and inflation pressure are influential parameters which affect the elongation behaviour of the actuator. Thin (1.5 mm) sectioned actuators produced 76.97% more elongation compared to thick sectioned, but the stress induced is 89.61 % higher. Whereas, the thick sectioned actuator (6 mm) showed a higher load transmitting capability. With change in wall thickness from 1.5 mm to 6 mm, the elongation is reduced by 76.97 %, 38.35 %, 21.05 % and 11.43 % at pressure 100 kPa, 75 kPa, 50 kPa and 25 kPa respectively. The induced stress is also found reduced by 89.61 %, 86.66 %, 84.46 % and 68.68 % at these pressures. The average load carrying capacity of the actuator is found to be directly proportional to its wall thickness and inflation pressure.


2014 ◽  
Vol 11 (1) ◽  
pp. 51
Author(s):  
Mohd Helmy Ibrahim ◽  
Mohd Nazip Suratman ◽  
Razali Abd Kader

Trees planted from agroforestry practices can become valuable resources in meeting the wood requirements of many nations. Gliricidia sepium is an exotic species introduced to the agricultural sector in Malaysia mainly for providing shade for cocoa and coffee plantations. This study investigates its wood physical properties (specific gravity and moisture content) and fibre morphology (length, lumen diameter and cell wall thickness) of G. sepium at three intervals according to age groups ( three, five and seven years of ages). Specific gravity (0.72) was significantly higher at seven years ofage as compared to five (0.41) and three (0.35) years age group with a mean of 0.43 (p<0.05). Mean moisture content was 58.3% with no significant difference existing between the tree age groups. Fibre diameter (22.4 mm) was significantly lower (p<0.05) for the trees which were three years of age when compared to five and seven years age groups (26.6 mm and 24. 7 mm), respectively. Means of fibre length, lumen diameter and cell wall thickness were 0.83 mm, 18.3 mm, and 6.2 mm, respectively, with no significant differences detected between trees in all age groups. Further calculation on the coefficient of suppleness and runkel ratio suggest that wood from G.sepium may have the potential for insulation board manufacturing and paper making. However, future studies should experiment the utilisation of this species for these products to determine its full potential.


Author(s):  
J Downing ◽  
A Hook

Two steel substrate test panels were developed to represent common plate thicknesses found on naval vessels and scanned using the Babcock developed ultrasonic technique. One sample comprised of a series of slotted surface breaking flaws of varying widths and through thicknesses to represent fracturing/cracking. The inspection method detected simulated cracking to a depth of 2mm and 0.5mm in width. The second sample included numerous loss of wall thickness areas of varying diameters and through thicknesses, with the smallest detectable loss of wall thickness being 0.1mm at a 15mm diameter. After proving confidence in detection, there was a need to characterise flaws to provide support and ascertain a repair action. Samples were produced that were subjected to either impact or heat exposure to induce realistic representative damage. The practical ultrasonic method was successfully used to independently characterise between the samples, with induced de-laminations caused by blisters, and multi layered matrix cracking caused by varying levels of projectile impacts, due to their unique morphology.


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