scholarly journals Experimental Investigations on Penetration Rate of Percussive Drill

2015 ◽  
Vol 11 ◽  
pp. 89-99 ◽  
Author(s):  
S.B. Kivade ◽  
Ch. S.N. Murthy ◽  
Harsha Vardhan
2016 ◽  
Vol 100 ◽  
pp. 207-212 ◽  
Author(s):  
Yoseph Bar-Cohen ◽  
Kris Zacny ◽  
Mircea Badescu ◽  
Hyeong Jae Lee ◽  
Stewart Sherrit ◽  
...  

Two of the key purposes of future NASA’s solar system exploration of planetary bodies are the search for potentially preserved bio-signatures and for habitable regions. To address these objectives, a biologically inspired wireline deep rotary-percussive drill, called Auto-Gopher, has been developed. This drill employs a piezoelectric actuated percussive mechanism for generating impulsive stresses and breaking formations, and an electric motor to rotate the bit to break material and remove the cuttings. Initially, the drill was designed as percussive mechanism for sampling ice and was demonstrated in 2005 at Lake Vida, Antarctica, reaching about 2 m depth. The lessons learned suggested there is a need to augment the percussive action with bit rotation in order to maximize the penetration rate. The first generation implementation of the rotary augmentation was focused on the demonstration of this capability. In 2012, during the 3-day field test, the drill reached a 3-meter deep in gypsum. A separate mechanism was used to break and remove the cores. The average drilling power consumption was in the range of 100-150 Watts, while the rate of penetration was approximately 2.4 m/hr. Currently under development is the second-generation drill, called Auto-Gopher 2. The drill will be fully autonomous. In this paper, the capabilities that are being integrated into the Auto-Gopher-2 are described and discussed.


Author(s):  
Luiz Fernando P. Franca ◽  
Hans Ingo Weber

New drilling techniques have been studied to increase the penetration in hard rock. These techniques use harmonic load and, in some cases, also impacts to generate a greater penetration rate. Analyzing only a percussive penetration phenomenon, the new model presented in this paper allows the forward motion (with a drift) in stick-slip condition without impact. Numerical and experimental investigations are presented and are qualitatively compared. Expanding the numerical analysis it is shown that the behavior may vary from periodic to chaotic motion.


2000 ◽  
Vol 21 (3) ◽  
pp. 322-328 ◽  
Author(s):  
T ZAHNERT ◽  
K HUTTENBRINK ◽  
D MURBE ◽  
M BORNITZ

1987 ◽  
Vol 48 (C5) ◽  
pp. C5-183-C5-186
Author(s):  
J. BLEUSE ◽  
P. VOISIN ◽  
M. VOOS ◽  
L. L. CHANG ◽  
L. ESAKI

2020 ◽  
pp. 51-58
Author(s):  
Aleksandr I. Kazmin ◽  
Pavel A. Fedjunin

One of the most important diagnostic problems multilayer dielectric materials and coatings is the development of methods for quantitative interpretation of the checkout results their electrophysical and geometric parameters. The results of a study of the potential informativeness of the multi-frequency radio wave method of surface electromagnetic waves during reconstruction of the electrophysical and geometric parameters of multilayer dielectric coatings are presented. The simulation model is presented that makes it possible to evaluate of the accuracy of reconstruction of the electrophysical and geometric parameters of multilayer dielectric coatings. The model takes into account the values of the electrophysical and geometric parameters of the coating, the noise level in the measurement data and the measurement bandwidth. The results of simulation and experimental investigations of reconstruction of the structure of relative permittivitties and thicknesses of single-layer and double-layer dielectric coatings with different thicknesses, with different values of the standard deviation (RMS) of the noise level in the measured attenuation coefficients of the surface slow electromagnetic wave are presented. Coatings based on the following materials were investigated: polymethyl methacrylate, F-4D PTFE, RO3010. The accuracy of reconstruction of the electrophysical parameters of the layers decreases with an increase in the number of evaluated parameters and an increase in the noise level. The accuracy of the estimates of the electrophysical parameters of the layers also decreases with a decrease in their relative permittivity and thickness. The results of experimental studies confirm the adequacy of the developed simulation model. The presented model allows for a specific measuring complex that implements the multi-frequency radio wave method of surface electromagnetic waves, to quantify the potential possibilities for the accuracy of reconstruction of the electrophysical and geometric parameters of multilayer dielectric materials and coatings. Experimental investigations and simulation results of a multilayer dielectric coating demonstrated the theoretical capabilities gained relative error permittivity and thickness of the individual layers with relative error not greater than 10 %, with a measurement bandwidth of 1 GHz and RMS of noise level 0,003–0,004.


1961 ◽  
Vol 38 (1) ◽  
pp. 73-87 ◽  
Author(s):  
Christian Lauritzen ◽  
Semih Velibese

ABSTRACT A description is given of experimental investigations and preliminary clinical experience with the long-acting oestriol compound polyoestriol phosphate – a water-soluble polymere of oestriol and phosphoric acid. The compound seems to exert all the physiologically important effects of oestriol. Even with high doses the hormone causes no proliferation of the endometrium and no withdrawal bleeding. It has no untoward effect on metabolism. It decreases slightly the cholesterol concentration (to the extent of ⅓–⅕ of the effect produced by long-acting oestradiol esters). The compound has a wide therapeutic range. No side-effects have been observed. Doses of 10 mg or more have a prolonged duration. Additional prolongation of the effect is largely dependent on dosage. To ensure an effect lasting for 4 weeks 40 mg polyoestriol phosphate (corresponding with 30 mg oestriol) is required – an amount which roughly corresponds with physiological quantitative data. The compound, which involves an interesting new principle of prolongation, was most effectively used in the treatment of menopausal symptoms and genital organic disorders. For these indications it can be recommended without reservation.


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