Experimental study of the relation between the relative resistance of rock and punch penetration depth

2014 ◽  
Vol 698 ◽  
pp. 529-533
Author(s):  
Alexander Petrovich Osipov ◽  
Victor Vassilevich Fedotov ◽  
Alexander Alexandrovich Zharov

In machining with grinding, it is necessary to know values of geometrical parameters of cutting edges of abrasive grains. In this paper for modeling of cutting edges of abrasive grains with rotation surfaces based on generatrix as a power function and for division cutting edges on both plowing and forming a chip, values of basic parametersBP,NPwere obtained experimentally. The influence of abrasive grain size, sieve-shaking procedure, mechanical properties of workpiece and type of abrasive material on these parameters was determined. The restrictions of this model were designated. It is established that traditional parameters such as corner radiusrand apex angle 2θ can be used in case of microcutting with small grain penetration depth.


2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Said Dhaimy ◽  
Sara Imdary ◽  
Sara Dhoum ◽  
Imane Benkiran ◽  
Amal El Ouazzani

Introduction. This experimental study is to compare radiographs based on the penetration depth of the irrigant following three final irrigation techniques.Material and Method. A sample of sixty teeth with single roots were prepared with stainless steel K files followed by mechanized Ni-Ti files iRace® under irrigation with 2.5% sodium hypochlorite. Radiopaque solution was utilized to measure the penetration depth of the irrigant. Three irrigation techniques were performed during this study: (i) passive irrigation, (ii) manually activated irrigation, and (iii) passive irrigation with an endodontic needle CANAL CLEAN®. Radiographs were performed to measure the length of irrigant penetration in each technique.Results. In comparison, passive irrigation with a conventional syringe showed infiltration of the irrigant by an average of0.682±0.105, whereas the manually activated irrigation technique indicated an average of0.876±0.066infiltration. Irrigation with an endodontic syringe showed an average infiltration of0.910±0.043. The results revealed highly significant difference between the three irrigation techniques (α=5%).Conclusion. Adding manual activation to the irrigant improved the result by 20%. This study indicates that passive irrigation with an endodontic needle has proved to be the most effective irrigation technique of the canal system.


2017 ◽  
Vol 1 (2) ◽  
pp. 157
Author(s):  
Danang D. Cahyadi ◽  
Yoga N. Adhitama ◽  
Ikhsan Setiawan ◽  
Agung B. S. Utomo

<p class="Abstract">Thermoacoustic prime movers work by using thermal energy to produce acoustic energy in the form of sound wave through thermoacoustic effect which occurs in a porous medium called stack. This paper describes an experimental study on the relation between the order of resonance frequencies generated by a thermoacoustic prime mover and the length of the resonator and the viscous penetration depth. Extending the resonator length will decreasing the resonance frequency which result in the increasing in the viscous penetration depth. Generally, the generated sound consists of only one frequency, that is the first-order one. However, under certain conditions, the sound has only the second-order frequency or comprises two frequencies of the first-order and second-order resonance frequencies. This phenomenon can be explained by considering the comparison between the effective hydraulic radius of stack () and the viscous penetration depth (). It is found that the first-order frequency appears when , while when   (with  calculated by using the first-order frequency) then the second order frequency is produced so that  is back to a smaller value and therefore the condition of  is recovered. In addition, when of  the thermoacoustic prime mover will<em> </em>generate the first and second order frequencies together.</p>


Author(s):  
Douglas Ricardo Sansão ◽  
L. Enrique Ortiz-Vidal ◽  
Oscar Mauricio Hernandez Rodriguez ◽  
Pedro José Miranda Lugo

2020 ◽  
Vol 257 ◽  
pp. 119595
Author(s):  
Janez Perko ◽  
Rafael Zarzuela ◽  
Inés Garcia-Lodeiro ◽  
María Teresa Blanco-Varela ◽  
Maria J. Mosquera ◽  
...  

2020 ◽  
Vol 10 (13) ◽  
pp. 4581
Author(s):  
Amal Kabalan

Micropillar arrays with radial p–n junctions are attractive for photovoltaic applications, because the light absorption and carrier collection become decoupled. The main challenge in manufacturing radial p–n junctions is achieving shallow (dopant depth <200 nm) and heavy doping (>1020 cm−3) that will allow the formation of a quasi-neutral region (QNR) and space charge region (SCR) in its tiny geometry. This experimental study investigates an approach that allows shallow and heavy doping in silicon micropillars. It aims to demonstrate that silicon dioxide (SiO2) can be used to control the dopant penetration depth in silicon micropillars.


1971 ◽  
Vol 8 (2) ◽  
pp. 151-162 ◽  
Author(s):  
Sven–Erik Rehnman ◽  
Bengt B. Broms

An experimental study is presented on the point bearing capacity of piles in rock. The bearing capacity for granite, limestone, and sandstone was found to be approximately four to six times the unconfined compressive strength of the rock material when the load was applied perpendicular to the rock surface. The ultimate bearing capacity was affected by the inclination of the applied load and by the penetration depth. The ultimate strength decreased rapidly when the inclination exceeded 45°. The strength increased with increasing penetration depth. The increase for granite and sandstone was 25 to 50% when the depth increased from 0 to 1.0 times the point diameter. The corresponding increase for limestone was 60 to 70%.The point bearing capacity was calculated by the Coulomb–Mohr and by the Griffith failure theories. The test results indicated that the effect of the inclination of the rock surface and of the penetration depth for granite and sandstone was less than calculated. Satisfactory agreement was found for the limestone between measured and calculated values. Comparisons with the Griffith failure theory indicated that the measured failure loads were approximately twice the calculated failure loads.


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