Application of laser"shock"wave treatment to increase crack resistance of materials

A finite element model is developed for predicting the appearance of new and the propagation of existing cracks during laser-shock-wave treatment (LSWT) of materials with linear and V-shaped cracks. The optimal modes of LSWT were determined for the maximum reduction in the rate of crack propagation. Keywords laser-shock-wave treatment, finite element method, residual stresses, stress intensity factor, crack growth rate, crack resistance. [email protected]

New well-head device for shock-wave treatment of bottomhole zone

For the implementation of shock-wave treatment on bottomhole zone of formation, there are various devices not providing efficient resonant shakedown of borehole fluid column creating shock waves of pressure and vacuum, which is not efficiently productive and reliable as well. To reduce filtration resistances and reset hydrodynamic relation of the reservoir and well, a new construction of wellhead device for shock-wave treatment on bottomhole zone, which may be used for increasing oil recovery rate via the effect through the well on Productive Series during completion and repair of producing well, has been developed. By developing a reliable and constant pressed airflow with low pressure, the paper solves the task of increasing the frequency of closing and opening of wellhead device, enabling to use it for creating shocking waves of pressure and vacuum in the well. The implementation of developed device improving hydrodynamic relations and hereby, simplifying filtration in the “reservoir-well” system, puts in production low permeable and isolated zones of Productive Series, which promotes the oil recovery rate increase and reduce oil prime cost as well.

Effect of Shock Wave on Vascular Lesions in Diabetic Rats

Background: Diabetes is one of the most common diseases in today’s society. Diabetes can cause multiple vascular lesions in the body, renal insufficiency, blindness, and so on. However, the evidence concerning the role of extracorporeal shock wave therapy in diabetic vascular disease is insufficient. Objectives: Observation of the effect of shock wave on vascular lesions in diabetic rats. Study Design: This study used an experimental design. Setting: The research took place in the laboratory research center at The Third Military Medical University. Methods: Eighteen healthy adult male Sprague Dawley rats were randomly divided into 3 groups: normal control group (group A), diabetic group (group B), and diabetes + shock wave treatment group (group C). Groups B and C were established by intraperitoneal injection of streptozotocin 60 mg/kg to demonstrate a diabetic rat model. Shock wave treatment was performed on the left lower extremity femoral artery in group C for 1 week (T1), 2 weeks (T2), 3 weeks (T3), and 4 weeks (T4) while the other 2 groups were reared normally. At the end of T4 shock wave treatment, the femoral arteries of each group were observed under an electron microscope. The expression of vascular endothelial growth factors (VEGF), endothelial nitric oxide synthase (eNOS), and angiotensin type 1 (AT1) were measured by western blot, and the changes of VEGF expression were detected by real-time polymerase chain reaction. Results: The VEGF and eNOS in group C were higher than those in group B (P < 0.05). The AT1 of the rats in the B and C groups was significantly higher than that in the A group (P < 0.05), but the C group was significantly lower than the B group (P < 0.05). After shock wave therapy, the surface of vascular endothelium in group C was flatter and smoother than that in group B, and the endothelial basement membrane and foot process were relatively tight. Limitations: Potential mechanisms that underlie the relationship between vascular dysfunction and diabetic neuropathy pain were not examined in this study. Conclusions: Shock wave may promote the formation of new blood vessels and improve vasomotor function by upregulating VEGF, eNOS, and downregulation of AT1 in diabetic rats and improve the damage of blood glucose to blood vessels to some extent. Key words: Shock wave, diabetic rats, vascular dysfunction, neovascularization