Propagation of solitary waves through signicantly curved shallow water channels

Propagation of solitary waves in curved shallow water channels of constant depth and width is investigated by carrying out numerical simulations based on the generalized weakly nonlinear and weakly dispersive Boussinesq model. The objective is to investigate the effects of channel width and bending sharpness on the transmission and reflection of long waves propagating through significantly curved channels. Our numerical results show that, when travelling through narrow channel bends including both smooth and sharp-cornered 90°-bends, a solitary wave is transmitted almost completely with little reflection and scattering. For wide channel bends, we find that, if the bend is rounded and smooth, a solitary wave is still fully transmitted with little backward reflection, but the transmitted wave will no longer preserve the shape of the original solitary wave but will disintegrate into several smaller waves. For solitary waves travelling through wide sharp-cornered 90°-bends, wave reflection is seen to be very significant, and the wider the channel bend, the stronger the reflected wave amplitude. Our numerical results for waves in sharp-cornered 90°-bends revealed a similarity relationship which indicates that the ratios of the transmitted and reflected wave amplitude, excess mass and energy to the original wave amplitude, mass and energy all depend on one single dimensionless parameter, namely the ratio of the channel width b to the effective wavelength [lambda][sub]e. Quantitative results for predicting wave transmission and reflection based on b/[lambda][sub]e are presented

The boundary contour method for magneto-electro-elastic media with quadratic boundary elements

AbstractThis paper presents a development of the boundary contour method (BCM) for magneto-electro-elastic media. First, the divergence-free of the integrand of the magneto-electro-elastic boundary element is proved. Second, the boundary contour method formulations are obtained by introducing quadratic shape functions and Green’s functions [Ding, H.J., Jiang, A.M., 2004. A boundary integral formulation and solution for 2D problems in magneto-electro-elastic media. Computers and Structures, 82 (20–21), 1599–1607] for magneto-electro-elastic media and using the rigid body motion solution to regularize the BCM and avoid computation of the corner tensor. The BCM is applied to the problem of magneto-electro-elastic media. Finally, numerical solutions for illustrative examples are compared with exact ones. The numerical results of the BCM coincide very well with the exact solution, and the feasibility and efficiency of the method are verified

Combined laparoscopy and hysteroscopy vs. uterine curettage in the uterine artery embolization-based management of cesarean scar pregnancy: a retrospective cohort study

BACKGROUND: The number of cesarean scar pregnancy (CSP) has significantly increased in the recent decade. Although uterine artery embolization (UAE) has been adopted to minimize the blood loss during uterine curettage removing of CSP, massive bleeding and uterine rupture can still be frequently encountered. The aim of this study was to compare the efficacy and safety of a novel combined laparoscopy and hysteroscopy technique with the traditional curettage in removing the conceptus and repairing the incision defect following the UAE management of CSP. METHODS: The CSP patients (n = 58) diagnosed between March 1, 2005 and March 1, 2010 were enrolled in three medical centers in Shanghai, China. All of these patients have undergone intra-arterial methotrexate, UAE and one of the following treatments: combined laparoscopy and hysteroscopy (study group, n = 25) and uterine curettage (control group, n = 33). Their medical records and 2-year outcomes were reviewed. The CSP removal rate, amount of blood loss during the treatment, incision repair rate (note: the post-curettage healing process of the incision defect was seen as a form of natural incision repairing, i.e., the self-repair mode), hospital stay, β-hCG regression time and postoperative sequelae were compared between two groups. RESULTS: The CSP removal rate in the study group (100%) was significantly higher than that (79%) in the control group (p = 0.024). The average blood loss was 78.0 mL in the study group, which was much less than the 258.5 mL (p = 0.004) in the control group. A satisfactory incision repair rate (96%) was achieved in the study group, while it was 25% (p < 0.001) in the control group. Moreover, the study group had significantly shorter hospital stays (p = 0.043) and β-hCG regression times (p = 0.033), lower rates of postoperative abdominal pain (p = 0.035) and menstruation abnormalities (p = 0.043). CONCLUSIONS: Combined laparoscopy and hysteroscopy is much safer and more effective than uterine curettage as a supplementary measure to remove the conceptus and repair the cesarean incision following the UAE management of CSP