The penetration of magnetic field into superimposed films of normal and superconducting metals

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The effect of turbulence and shear on the flow around three dimensional square cylinders

PhDThe effect of turbulence and shear on the flow around square cylinders has been investigated (i) for models without a free end at incidence a in the range 00<a< 45 0 for models with and without end plates and, (ii) for models with a free end at a=00 and a= 45 0 for model height H to width D ratio H/D in the range 2 :5 H/D 5 11. The Reynolds number, based on 4 the model width was 4.8 x 10 It has been found that end plates are necessary to simulate a two dimensional flow condition in uniform smooth flow provided the wall boundary layer is greater than about 10% of the model span. In other uniform flow conditions, away from the wall boundary layer affected region, which is about the physical thickness of the boundary layer, two dimensionality could be assumed. In linear shear flow., end plates reduced the base pressure in the low velocity region. Two dimensional model results agree well with the published results. Finite square cross-section cylinders exhibit a free end region of length ZF and a root region. Three regimes, Low H/D, Middle H/D and High H/D are found in all flow conditions. The drag on the finite cylinder in smooth flow is lower than that in turbulent flows. Provided the flow is turbulent, increasing turbulence decreases the drag. For a particular flow condition, increasing H/D ratio increases the drag. It appears that in the high H/D regime there is a shedding of the free end eddy. The shedding frequency is lower than the shedding frequency in the root region of the cylinder. The effect of shear can be ascertained by correcting the flow results for the local velocity and thus shear need not be considered a critical flow simulation parameter

Unroofed coronary sinus and coronary sinus orifice atresia Implications for management of complex congenital heart disease

Objectives.The aim of this study was to assess the morphology of the coronary sinus, its drainage and associated cardiac malformations when there is either complete unroofing of the coronary sinus or atresia of its connection to the right atrium.Background.As more children with complex cardiac anomalies are accepted for primary surgical repair or palliation with cavopulmonary anastomoses, a knowledge of coronary sinus and systemic venous anomalies is important if coronary venous return is to be preserved and residual shunts avoided.Methods.Twenty-six heart-lung specimens without a coronary sinus draining to the right atrium were identified from the Leiden collection of congenital heart malformations. These were classified into specimens with an unroofed coronary sinus and those with atresia of the coronary sinus orifice. Attention was paid to the associated cardiac malformations.Results.In 14 (54%; confidence limits [CL] 35%, 73%) of 26 specimens, there was an unroofed coronary sinus, associated with persistence of the left superior caval vein. An inferoposterior location of an atrial septal defect was detected in 2 (14%; CL –4%, 33%) of 14. Atrial appendage anomalies were seen in 13 (93%; CL 79%, 106%) of 14 specimens, exemplified by both right and left isomerism. These were frequently associated with an atrioventricular septal defect (12 [86%; CL 67%, 104%] of 14). An atretic coronary sinus orifice was seen in 12 (46%; CL 27%, 65%) of 26. Atrial appendage anomalies (2 [17%; CL –4%, 38%] of 12) were rare in these cases. The drainage was then by way of a left superior caval vein or, in its absence, a coronary sinus to left atrial window. Ventricular hypoplasia was seen in both categories of coronary sinus abnormalities. Important ventricular hypoplasia was seen in 12 cases (46%; CL 27%, 65%).Conclusions.These findings emphasize the need to study coronary sinus drainage before procedures such as ligation or transcatheter coil embolization of a left superior caval vein, venous redirection or closure of a dorsal atrial septal defect are contemplated. These procedures might inadvertently lead to impairment of coronary venous return or persistence of an intracardiac shunt

Fracture resistance and surface treatment of Y-TZP prepable ceramic abutments and bars

Intraoral preparation of zirconia implant abutments creates deep surface defects making abutments susceptible to fracture during loading. Fracture strengths were tested for (1) HIP-processed zirconia bars (Astra-Tech) after preparation and/or surface repair treatments: no preparation (NP), dry-preparation (DP), wet-preparation (WP), or we-tpreparation and 30d water storage (WP+30d), mitigating treatment of bonding agent (WP+B), sandblasting (WP+SB), or polishing (WP+P), and (2) abutment-assemblies (preparations of 0, 0.5, or 1mm margin reduction). NP established the strength for pristine zirconia bars (1634 plus or minus 95MPa). DP (1144 plus or minus 109MPa), WP (1442 plus or minus 89MPa), WP+30d (1193 plus or minus155MPa), and WP+B (1218 plus or minus 77MPa) groups had significantly (p less than or equal to 0.05) reduced strengths. WP+SB (1632 plus or minus 134MPa) or WP+P (1664 plus or minus 176MPa) repairs equally well recovered original strengths (p0.05) among different abutment-assembly groups and no logical relationship of strength to increasing amount of reduction. All fractures occurred at the interface where the abutment was connected to the analog, suggesting that fracture was unrelated to the actual abutment

Combined effects of nitric oxide and oxygen during acute pulmonary vasodilator testing

AbstractOBJECTIVESWe compared the ability of inhaled nitric oxide (NO), oxygen (O2) and nitric oxide in oxygen (NO+O2) to identify reactive pulmonary vasculature in pulmonary hypertensive patients during acute vasodilator testing at cardiac catheterization.BACKGROUNDIn patients with pulmonary hypertension, decisions regarding suitability for corrective surgery, transplantation and assessment of long-term prognosis are based on results obtained during acute pulmonary vasodilator testing.METHODSIn group 1, 46 patients had hemodynamic measurements in room air (RA), 100% O2, return to RA and NO (80 parts per million [ppm] in RA). In group 2, 25 additional patients were studied in RA, 100% O2and 80 ppm NO in oxygen (NO+O2).RESULTSIn group 1, O2decreased pulmonary vascular resistance (PVR) (mean ± SEM) from 17.2 ± 2.1 U·m2to 11.1 ± 1.5 U·m2(p < 0.05). Nitric oxide caused a comparable decrease from 17.8 ± 2.2 U·m2to 11.7 ± 1.7 U·m2(p < 0.05). In group 2, PVR decreased from 20.1 ± 2.6 U·m2to 14.3 ± 1.9 U·m2in O2(p < 0.05) and further to 10.5 ± 1.7 U·m2in NO+O2(p < 0.05). A response of 20% or more reduction in PVR was seen in 22/25 patients with NO+O2compared with 16/25 in O2alone (p = 0.01).CONCLUSIONSInhaled NO and O2produced a similar degree of selective pulmonary vasodilation. Our data suggest that combination testing with NO+O2provides additional pulmonary vasodilation in patients with a reactive pulmonary vascular bed in a selective, safe and expeditious fashion during cardiac catheterization. The combination of NO+O2identifies patients with significant pulmonary vasoreactivity who might not be recognized if O2or NO were used separately

AV-Deepfake1M: A Large-Scale LLM-Driven Audio-Visual Deepfake Dataset

The detection and localization of highly realistic deepfake audio-visual content are challenging even for the most advanced state-of-the-art methods. While most of the research efforts in this domain are focused on detecting high-quality deepfake images and videos, only a few works address the problem of the localization of small segments of audio-visual manipulations embedded in real videos. In this research, we emulate the process of such content generation and propose the AV-Deepfake1M dataset. The dataset contains content-driven (i) video manipulations, (ii) audio manipulations, and (iii) audio-visual manipulations for more than 2K subjects resulting in a total of more than 1M videos. The paper provides a thorough description of the proposed data generation pipeline accompanied by a rigorous analysis of the quality of the generated data. The comprehensive benchmark of the proposed dataset utilizing state-of-the-art deepfake detection and localization methods indicates a significant drop in performance compared to previous datasets. The proposed dataset will play a vital role in building the next-generation deepfake localization methods. The dataset and associated code are available at https://github.com/ControlNet/AV-Deepfake1M