Theory of the limiting equilibrium of cylindrical samples with external annular cracks

1975 ◽  
Vol 10 (3) ◽  
pp. 258-266
Author(s):  
A. E. Andreikiv ◽  
V. V. Panasyuk ◽  
I. N. Pan'ko
Keyword(s):  
Limiting Equilibrium ◽  
Cylindrical Samples ◽  
Annular Cracks

Investigation of irradiated metal of WWER-type reactor internals after 45 years of operation. Part 1. Research program and cutting out of samples from pressure vessel internals

2020 ◽  
pp. 135-143
Author(s):  
B. Z. Margolin ◽  
A. Ya. Varovin ◽  
A. J. Minkin ◽  
D. A. Gurin ◽  
V. A. Glukhov
Keyword(s):  
Research Program ◽  
Pressure Vessel ◽  
The Core ◽  
Type Reactor ◽  
Cutting Out ◽  
Cylindrical Samples ◽  
Reactor Internals

The program is presented for investigations of the metal of the most irradiated elements of the WWER-440 reactor of the Novovoronezh NPP Unit 3 decommissioned after 45 years of operation. The fragments (cylindrical samples) were cut out from various zones of the core baffle and segment of forming ring of core barrel.

scholarly journals Kinetics of the Boride Layers Obtained on AISI 1018 Steel by Considering the Amount of Matter Involved

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 259 ◽  
Author(s):  
Pablo A. Ruiz-Trabolsi ◽  
Julio Cesar Velázquez ◽  
Carlos Orozco-Álvarez ◽  
Rafael Carrera-Espinoza ◽  
Jorge A. Yescas-Hernández ◽  
...  
Keyword(s):  
Sample Size ◽  
Growth Kinetics ◽  
Duration Of Treatment ◽  
Solid Diffusion ◽  
Treatment Conditions ◽  
Wear And Corrosion ◽  
Different Diameters ◽  
Boriding Process ◽  
Kinetics Of ◽  
Cylindrical Samples

Boride layers are typically used to combat the wear and corrosion of metals. For this reason, to improve our knowledge of the boriding process, this research studied the effect of the size of the treated material on the kinetics of the growth of the boride layers obtained during a solid diffusion process. The purpose was to elucidate how the layers’ growth kinetics could be affected by the size of the samples since, as the amount of matter increases, the amount of energy necessary to make the process occur also increases. Furthermore, the level of activation energy seems to change as a function of the sample size, although it is considered an intrinsic parameter of each material. Six cylindrical samples with different diameters were exposed to the boriding process for three different exposure times (1.5, 3, and 5 h). The treatment temperatures used were 900, 950, and 1000 °C for each size and duration of treatment. The results show that the layer thickness increased not only as a function of the treatment conditions but also as a function of the sample diameter. The influence of the sample size on the growth kinetics of the boride layers is clear, because the growth rate increased even though the treatment conditions (time and temperature) remained constant.

scholarly journals The dynamics of cylindrical samples in dual wind-up extensional rheometers

2011 ◽  
Vol 55 (3) ◽  
pp. 571-580 ◽  
Author(s):  
Kaijia Yu ◽  
Henrik Koblitz Rasmussen ◽  
Jose Manuel Román Marín ◽  
Ole Hassager
Keyword(s):  
Cylindrical Samples

Effect of Paper Sludge Ash on the Compressive Strength of Plaster of Paris/Paper Sludge Ash Composites

2012 ◽  
Vol 501 ◽  
pp. 34-38 ◽  
Author(s):  
Kar Keng Lim ◽  
Roslinda Shamsudin ◽  
Muhammad Azmi Abdul Hamid
Keyword(s):  
Compressive Strength ◽  
Construction Material ◽  
Paper Industry ◽  
Pulp And Paper Industry ◽  
Paper Sludge ◽  
Mixed Powder ◽  
Plaster Of Paris ◽  
Paper Sludge Ash ◽  
Sludge Ash ◽  
Cylindrical Samples

In this study, paper sludge ash, a waste from pulp and paper industry was used as a filler in fabricating Plaster of Paris/paper sludge ash composites. Various percentage of paper sludge ash was used, namely 1wt.%, 3wt.%, 5wt.% and 7wt.%. The effect of paper sludge ash on the compressive strength of the Plaster of Paris was studied. The mixed powder of paper sludge ash and Plaster of Paris were form into a 6 mm diameter and 12 mm height cylindrical samples. The composites were characterized theirs density where it shows that the density decreased as the amount of paper sludge ash increased. The compressive strength of the composites also decreased from 11.67 MPa without paper sludge ash addition to 0.50 MPa at 7wt.% paper sludge ash. However, the requirement of strength for Plaster of Paris in industry is between 8.96 MPa to 20.68 MPa. From the SEM observation, sample contain higher percentage of paper sludge ash exhibited more porosity. Therefore with the addition of 1wt.% of paper sludge ash into Plaster of Paris can be a promising construction material.

Ultrasonic Test on Recycled Concrete: Relationship among Ultrasonic Waves Velocity, Compressive Strength and Elastic Modulus

2014 ◽  
Vol 894 ◽  
pp. 45-49 ◽  
Author(s):  
Luisa Pani ◽  
Lorena Francesconi
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Ultrasonic Wave ◽  
Ultrasonic Test ◽  
Ultrasonic Waves ◽  
Recycled Concrete ◽  
Recycled Aggregates ◽  
Experimental Program ◽  
Static Modulus ◽  
Cylindrical Samples

In this paper an experimental program has been carried out in order to compare compressive strength fcand elastic static modulus Ecof recycled concrete with ultrasonic waves velocity Vp, to establish the possibility of employing nondestructive ultrasonic tests to qualify recycled concrete. 9 mix of concrete with different substitution percentage of recycled aggregates instead of natural ones and 27 cylindrical samples have been made. At first ultrasonic tests have been carried out on cylindrical samples, later elastic static modulus Ecand compressive strength fchave been experimentally evaluated. The dynamic elastic modulus Edhas been determined in function of ultrasonic wave velocity Vp; furthermore the correlations among Ed, Ec, fce Vphave been determined. It has been demonstrated that ultrasonic tests are suitable for evaluating different deformative and resisting concrete performances even when variations are small.

Variations in the Compression Strength of Cylindrical Samples Made of Dense Hydroxyapatite

2007 ◽  
Vol 361-363 ◽  
pp. 103-106 ◽  
Author(s):  
Sergey V. Dorozhkin ◽  
Oguzhan Gunduz ◽  
Faik N. Oktar
Keyword(s):  
Ambient Temperature ◽  
Compression Strength ◽  
Total Mass ◽  
Processing Parameters ◽  
Hydraulic Press ◽  
Geometrical Dimensions ◽  
Cylindrical Samples ◽  
Spray Dried

Dense bioceramics made of pure hydroxyapatite (HA) was prepared and characterized. The cylindrical samples were compacted from HA powders of diverse pretreatments; namely, from spray-dried HA, calcined HA and mixtures thereof. The samples were prepared by a hydraulic press under different compaction loads both with and without auxiliary compounds (a binder and a lubricant). Both the total mass and geometrical dimensions of the prepared cylinders were measured. Then, the cylindrical samples were sintered at 1200 °C for 4 hours. After cooling down to ambient temperature, the sintered cylinders were weighed and their geometrical dimensions were measured once again. Mass decreasing and the shrinkage degree were calculated as a result. Afterwards, the compression strength of the sintered cylinders was measured by an Instron 5587 machine. Preparation of dense HA bioceramics possessing the highest possible compression strength was the purpose of this study. The necessary processing parameters were discovered.

scholarly journals Bioactivity of PEEK GRF30 and Ti6Al4V SLM in Simulated Body Fluid and Hank’s Balanced Salt Solution

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2059
Author(s):  
Piotr Prochor ◽  
Żaneta Anna Mierzejewska
Keyword(s):  
Simulated Body Fluid ◽  
Salt Solution ◽  
Body Fluid ◽  
Stress Shielding ◽  
Shielding Effect ◽  
Orthopedic Implant ◽  
New Materials ◽  
Optical Analysis ◽  
Calcium Phosphate Layer ◽  
Cylindrical Samples

In recent years, scientists have defined two main paths for orthopedic implant fabrication: searching for new materials with properties closest to natural bone in order to reduce the stress-shielding effect or creating individually adapted geometry of the implant with the use and Rapid Prototyping methods. Therefore, materials such as PEEK GRF30 and Ti6Al4V selective laser melting (SLM) are of interest. They are defined as materials suitable for implants, however, the knowledge of their bioactivity, a feature which is one of the most desirable properties of biomaterials, is still insufficient. Using Simulated Body Fluid and Hank’s Balanced Salt Solution, the bioactivity of PEEK GRF30 and Ti6Al4V SLM was assessed, as well as commercial Ti6Al4V as a reference material. Ten cylindrical samples of each material were prepared and immersed in solutions per period from 2 to 28 days at 37 °C. Optical analysis of the changes on the examined surfaces suggested that right after 2-day crystals with different morphologies were formed on each material. Further analysis of the chemical composition of the altered surfaces confirmed the formation of a calcium phosphate layer on them, however, the Ca/P ratio was slightly different from 1.67. On the basis of the obtained results, it can be concluded that both PEEK GRF30 and Ti6Al4V SLM are characterized by appropriate—comparable to Ti6Al4V—bioactivity.

Extreme-Value Problems of Limiting Equilibrium

1979 ◽  
Vol 105 (10) ◽  
pp. 1155-1171
Author(s):  
Michael Garber ◽  
Rafael Baker
Keyword(s):  
Extreme Value ◽  
Limiting Equilibrium
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