Determination of shock waves by convergence acceleration

2005 ◽  
pp. 81-100
Author(s):  
Max Bausset
Keyword(s):  
Shock Waves ◽  
Convergence Acceleration

Use of non-contrast computed tomography determined urinary stone fragility in predicting the outcome of extracorporeal shockwave lithotripsy treatment: a single-center study

2020 ◽  
Vol 14 (2) ◽  
pp. 59-63
Author(s):  
Athar Hameed ◽  
Khazir Hayyat Gondal
Keyword(s):  
Shock Waves ◽  
Renal Stone ◽  
Plain Film ◽  
Renal Stones ◽  
Renal Calculus ◽  
Urinary Stone ◽  
Stone Disease ◽  
Urinary Stones ◽  
Fisher Exact Test

Background: Renal stones represent a common urological pathology where standard treatment advised is ESWL in current practice. However, NCCT based determination of stone fragility may help to predict the outcome of ESWL treatment, hence optimizing its clinical use. Therefore, this study evaluated the role of NCCT determined urinary stone fragility in predicting the outcome of ESWL treatment in local clinical settings. Patients and methods: One hundred patients with single renal calculus of 0.6-2 cm in size were included. NCCT based determination of stone fragility in HU units was done for all patients. Patients were then subjected to ESWL, with a maximum of 3000 shock waves given per ESWL session. Plain film and/or ultrasonography was used to monitor ESWL treatment progress with a final NCCT evaluation at 12 weeks to determine the clearance of the calculi for each patient. Association of NCCT based stone fragility and outcome of ESWL was statistically analyzed using Fisher exact test. Results: The mean age of the patients was 37.7 ± 10.9 years with 54% being male. Decreasing stone fragility on NCCT (high = <500HU, moderate = 500-1000HU, and high = 1000HU) required more number and intensity of ESWL sessions (1-2 visits and 3000-6000 shock waves for high stone fragility group, 3-5 visits and 7000-18000 shock waves for the moderate group, and 6 visits and >18000 shock waves for low fragility group, respectively) necessary for clearance of urinary stones (p<0.001). In 98% of patients, the clearance of urinary stones was excellent. Conclusion: Renal stone patients with NCCT determined high and moderate stone fragility show an optimal response after ESWL treatment, whereas, for low fragility renal stones attenuative treatment like percutaneous nephrolithotomy and/or ureteroscopy should be considered instead of ESWL. This approach can enable patient stratification before ESWL therapy ensuring better clinical management of the renal stone disease.

Experimental determination of the parameters behind strong reflected shock waves in air

1976 ◽  
Vol 12 (5) ◽  
pp. 683-686
Author(s):  
B. K. Tkachenko ◽  
S. I. Titarov ◽  
A. B. Karasev ◽  
S. V. Alipov
Keyword(s):  
Shock Waves ◽  
Experimental Determination ◽  
Reflected Shock

scholarly journals Determination of Forces under Hydroexplosion in a Restricted Environment. Part 1. Calculation of Forces Caused by the Action of Shock Waves

2016 ◽  
Vol 37 (2) ◽  
pp. 221-231
Author(s):  
Yu. O. Neveshkin ◽  
◽  
V. V. Ostapchuk ◽  
O. U. Solomianyi ◽  
◽  
...  
Keyword(s):  
Shock Waves ◽  
Restricted Environment

scholarly journals Comparison of oblique shock wave angle in analytical and numerical solution

2019 ◽  
Vol 31 ◽  
pp. 137-142 ◽  
Author(s):  
Assen Marinov
Keyword(s):  
Shock Wave ◽  
Shock Waves ◽  
Wave Drag ◽  
Oblique Shock Wave ◽  
Friction Drag ◽  
Total Drag ◽  
Induced Drag ◽  
Drag And Lift ◽  
Wave Angle

The drag of the subsonic aircraft is largely formed by the skin friction drag and lift-induced drag. At transonic flight occurs shock wave. Determination of shock wave angle is important part of design of every aircraft, which working in supersonic airflow regimes. Formation of shock waves cause formation the wave drag. The wave drag could account about 35% from total drag of aircraft. Shock wave angle is directly linked with the intensity of itself. This work compares shock wave angle calculations using analytical and numerical solving methods.

scholarly journals Advances in the investigation of shock-induced reflectivity of porous carbon

2013 ◽  
Vol 31 (3) ◽  
pp. 457-464 ◽  
Author(s):  
Dimitri Batani ◽  
Stefano Paleari ◽  
Tommaso Vinci ◽  
Roberto Benocci ◽  
Keisuke Shigemori ◽  
...  
Keyword(s):  
Shock Waves ◽  
Numerical Simulations ◽  
Porous Carbon ◽  
Simultaneous Measurement ◽  
Accurate Determination ◽  
Sample Temperature ◽  
Optical Pyrometry ◽  
Shock Dynamics

AbstractWe studied the behavior of porous carbon compressed by laser-generated shock waves. In particular, we developed a new design for targets, optimized for the investigation of carbon reflectivity at hundred-GPa pressures and eV/k temperatures. Specially designed “two-layer-two materials” targets, comprising porous carbon on transparent substrates, allowed the probing of carbon reflectivity and a quite accurate determination of the position in the P, T plane. This was achieved by the simultaneous measurement of shock breakout times, sample temperature (by optical pyrometry) and uid velocity. The experiments proved the new scheme is reliable and appropriate for reflectivity measurements of thermodynamical states lying out of the standard graphite or diamond hugoniot. An increase of reflectivity in carbon has been observed at 260 GPa and 14,000 K while no increase in reflectivity is found at 200 GPa and 20,000 K. We also discuss the role of numerical simulations in the optimization of target parameters and in clarifying shock dynamics.

Determination of the parameters of shock waves in liquid cementing agents

1970 ◽  
Vol 4 (11) ◽  
pp. 1014-1018
Author(s):  
D. M. Kushnarev
Keyword(s):  
Shock Waves
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