The cavitation peening (CP) and cavitation abrasive jet polishing (CAJP) processes employ a cavitating jet to harden the surface or remove surface irregularities. However, a zero incidence angle between the jet and the surface limits the efficiency of these two processes. This limitation can be improved by introducing a secondary jet. The secondary jet interacts with the main jet, carrying bubbles to the proximity of the workpiece surface and aligning the disordered bubble collapse events. Through characterizing the treated surface of AL6061 in terms of the hardness distribution and surface roughness, it was found out that the secondary jet can increase the hardening intensity by 10%, whereas the material removal rate within a localized region increased by 66%. In addition, employing multiple secondary jets can create a patched pattern of hardness distribution. Another finding is that the hardening effect of the cavitation increases with the processing time at first and is then saturated.
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http://dx.doi.org/10.3390/mi13010086 | DOI Listing |
J Invasive Cardiol
January 2025
Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Diseases, China; State Key Laboratory of Cardiovascular Diseases, Zhongshan Hospital, Fudan University; NHC Key Laboratory of Ischemic Heart Diseases; Key Laboratory of Viral Heart Diseases, Chinese Academy of Medical Sciences; National Clinical Research Center for Interventional Medicine, Shanghai, China.
Objectives: The ValveClamp system (Hanyu Medical Technology) is a novel transcatheter edge-to-edge repair (TEER) system designed for ease of operation; however, there is a lack of data on its application in secondary mitral regurgitation (SMR). The authors report the mid-term outcomes of TEER using the ValveClamp system in SMR.
Methods: The study prospectively analyzed consecutive severe SMR patients who underwent transapical ValveClamp implantation at 10 Chinese centers.
Can J Cardiol
January 2025
Department of Cardiology, Istituto Auxologico Italiano, IRCCS, Milan, Italy; Department of Medicine and Surgery, University of Milano- Bicocca, Milan, Italy.
Background: In patients with moderate and severe secondary tricuspid regurgitation (STR), the effective regurgitant orifice area (EROA), corrected using the proximal isovelocity surface area (PISA) method for tricuspid valve leaflet tethering and low TR jet velocities, has an unclear threshold for identifying high-risk patients. This study aimed to establish a risk-based EROA cutoff and assess the impact of right ventricular (RV) remodeling on outcomes in low-risk STR patients according to EROA.
Methods: We included 513 consecutive outpatients (age 75±13 years, 47% male) with moderate and severe STR.
Cureus
December 2024
Department of Neurological Surgery, Ryofukai Satoh Neurosurgical Hospital, Fukuyama, Hiroshima, JPN.
Coil embolization of cerebral aneurysms often encounters challenges in achieving complete filling of the aneurysm sac due to complex shapes and hemodynamic factors, frequently resulting in the formation of a residual cavity (RC) at the aneurysm neck. The hemodynamic mechanisms underlying RC formation and growth, however, remain poorly understood. Computational fluid dynamics (CFD) analysis, combined with silent MRA free from contrast agents and metal artifacts, offers a promising approach to elucidate these mechanisms, potentially enhancing the clinical management of cerebral aneurysms post-coiling.
View Article and Find Full Text PDFSci Rep
December 2024
School of Mechanical and Electrical Engineering, North University of China, Taiyuan, 030051, Shanxi, China.
Due to the sensitivity of the shaped charge jet to standoff and the complexity of its impact under lateral disturbances, this study aims to investigate the dynamic impact evolution of the jet influenced by standoff and lateral disturbances. A finite element model for the dynamic impact of shaped charge jets was established. Dynamic impact experiments were designed and conducted to validate the effectiveness of the numerical simulations.
View Article and Find Full Text PDFRev Sci Instrum
December 2024
College of Intelligent Manufacturing, Long Dong University, Qingyang, Gansu 745000, China.
The deflector jet pressure servo valve (DJPSV), a critical component of the aircraft brake servo system, requires a precise foundational model for performance analysis, optimization, and enhancement. However, the complexity of the jet process within the V-groove of the deflector plate presents challenges for accurate mathematical modeling. To address this issue, the paper takes the DJPSV as the research object, carries out detailed mathematical modeling of its components, analyzes the influencing factors of the performance of the key component-the front stage-and optimizes the design of the key factors.
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