Raptor wing morphing with flight speed

In gliding flight, birds morph their wings and tails to control their flight trajectory and speed. Using high-resolution videogrammetry, we reconstructed accurate and detailed three-dimensional geometries of gliding flights for three raptors (barn owl, Tyto alba ; tawny owl, Strix aluco , and goshawk, Accipiter gentilis ). Wing shapes were highly repeatable and shoulder actuation was a key component of reconfiguring the overall planform and controlling angle of attack. The three birds shared common spanwise patterns of wing twist, an inverse relationship between twist and peak camber, and held their wings depressed below their shoulder in an anhedral configuration. With increased speed, all three birds tended to reduce camber throughout the wing, and their wings bent in a saddle-shape pattern. A number of morphing features suggest that the coordinated movements of the wing and tail support efficient flight, and that the tail may act to modulate wing camber through indirect aeroelastic control.

Линейная динамика спиновых волн в массив ЖИГ-волноводов

The features of spin-wave transport in a system of coupled magnetic microwaveguides with perpendicular magnetization relative to the longitudinal axis of the system are considered. In this case, the system has uniaxial anisotropy, the horizontal and vertical coupling coefficients have different signs, and the isofrequency surfaces have a "saddle" shape. In the propagation of transversely limited beams of spin waves, the type of curvature of the wave fronts is determined by the direction of wave propagation relative to the external magnetic field.

Quantitative analysis of mitral annulus morphology in aortic stenosis using real time 3-dimentional transesophageal echocardiography

Background Normal mitral annulus morphology is known to be saddle shape. There are a few reports regarding the relationship between flattening of the mitral annular saddle shape and mitral regurgitation. However, the relationship between aortic stenosis (AS) and mitral annulus morphology is unknown. Purpose To assess the impact of AS on mitral annular saddle shape using 3-dimentional transesophageal echocardiography. Methods A total of consecutive 83 subjects including 44 patients with severe AS (AS group) and 39 patients without AS (control group), who underwent real-time 3-dimentional transesophageal echocardiography of the mitral valve, were enrolled. The 3-dimentional geometry of the mitral annulus apparatus was evaluated by the parameters analyzed using dedicated quantification software such as anteroposterior diameter (APD), commissural width (CW), annular height (AH), mitral annulus (MA) area and annular height to commissural width ratio (AHCWR) as shown in Figure. We assessed the impact of severe AS on AHCWR, which is the key parameter showing flattening of the mitral annular saddle shape. These parameters were adjusted by body surface area (BSA). Exclusion criteria included left ventricular ejection fraction <50%, the presence of aortic regurgitation, mitral valve disease, pericardial or congenital diseases, endocarditis, cardiomyopathy, prior myocardial infarction, and paroxysmal or persistent atrial fibrillation. Results Comparisons of mitral valve geometry between AS group and control group are summarized in Table. AH/BSA and AHCWR were significantly lower in AS group compared with control group. Multiple linear regression analysis revealed severe AS to be a significant and independent predictor of lowering AHCWR (β=−0.39, t=−4.04, p<0.001) (adjusted with MA area, selected by stepwise analysis). Conclusions Severe AS might contribute to flattening of the mitral annular saddle shape, lead to the mitral annular structural remodeling. Assessment of the mitral annulus morphology might help evaluating severe AS. Mitral annulus 3-dimensional geometry Funding Acknowledgement Type of funding source: None

The Development Law of the Freezing Temperature Field of a Calcareous Clay Layer

The problem of “difficult” freezing of the calcareous clay layer fractures in freezing pipes has been investigated. Based on the engineering background of the deep calcareous clay in the Yangcun Mine, model tests were carried out in order to conduct in-depth research on the development law of the freezing temperature field of this clay layer. The test results have shown that the calcareous clay has a freezing point of −1.3°C under the action of both the water and the soil’s chemistry and the supercooling temperature can be as low as −3.8°C because of its complex mineral composition causing poor thermal conductivity. This means that the calcareous clay will freeze slowly than the other layers of the soil. The time taking for the temperature fields to intersect is 2.5 h, which is equivalent to 127.6 days in the actual engineering. In the three sections, each temperature measurement point in the temperature field had an irregular saddle shape in the temperature space at the same time, and the ratio of the time between the formation and total melting of the frozen wall was 1 : 1.91. The development speed of the thickness of the frozen wall from 5 h to 16 h was 17.9 mm/h, and the development speed from 16 h to 70 h was 1.96 mm/h; corresponding to the actual development speed of the thickness of the frozen wall which were 0.0123 m/d and 0.0014 m/d, respectively. These speeds were significantly slower than the development speed of the thickness of the freezing wall of the general sandy clay layer, which were 0.0515 m/d in the early stage and 0.02 m/d in the later stage. The thin thickness and low strength of the frozen wall of the calcareous clay layer cause the fracture of the frozen pipes, which should be paid attention to in actual engineering construction.

P762 Preserved mitral apparatus dynamics predict the improvement of acute ischemic mitral regurgitation: four-dimensional quantitative echocardiographic study

Background We sought to evaluate the predictive value of acute stage mitral apparatus geometry and dynamics for the reduction of ischemic mitral regurgitation (IMR) in the remote phase after successful primary percutaneous coronary intervention (pPCI) by using real-time 3D-transthoracic echocardiography (3D-TTE). Methods We performed 2D and 3D-TTE in consecutive 44 first acute MI patients with more than mild IMR within 3 days after successful pPCI. 3DTTE of left ventricle (LV) volumes and mitral apparatus dynamics through the cardiac cycle were quantified offline. We compared the 3D geometric and dynamic parameters in the acute phase between 1)20 remained MR group and 2)24 improved MR group in 6-to-12 months after MI onset. Results Ejection fraction (EF) was preserved in the improved MR group compared to the remained MR group (49.0 ± 11.2 vs. 56.5 ± 7.0%, p = 0.013). Mitral valve annulus area, leaflet tenting length and papillary muscles spatial position had no significant difference between the two groups (all p > 0.05) throughout cardiac cycle. In contrast, mitral annulus saddle shape was preserved in the improved MR group than the remained MR group (p = 0.010) and annular area changed dynamically through early- to late-systole in the improved MR group (phasic p = 0.017) despite it was adynamic in remained MR group (phasic p = 0.201). Conclusions: IMR improvement in the remote phase after AMI associated with preserved EF, mitral annulus saddle shape and dynamics during systole in the acute phase of MI. 4D dynamics of the mitral apparatus can be clinically useful predictor of the improvement in acute IMR and may contribute to the clinical decision making including surgical or percutaneous intervention for IMR.

Shape Stability of Metallic Nanoplates: A Molecular Dynamics Study

Metallic nanoplates have attracted widespread interests owing to their functional versatility, which relies heavily on their morphologies. In this study, the shape stability of several metallic nanoplates with body-centered-cubic (bcc) lattices is investigated by employing molecular dynamics simulations. It is found that the nanoplate with (110) surface planes is the most stable compared to the ones with (111) and (001) surfaces, and their shapes evolve with different patterns as the temperature increases. The formation of differently orientated facets is observed in the (001) nanoplates, which leads to the accumulation of shear stress and thus results in the subsequent formation of saddle shape. The associated shape evolution is quantitatively characterized. Further simulations suggest that the shape stability could be tuned by facet orientations, nanoplate sizes (including diameter and thickness), and components.

P43673D analysis of mitral annular reshape with third generation MitraClip XTr in functional and degenerative mitral regurgitation

The 3rd generation Mitraclip XTr was recently introduced to improve device performance, through longer clip arms that should allow better grasping of the mitral leaflets, thus improving coaptation and results eventually. Several studies have demonstrated additional effects such as the reshape of the mitral annulus immediately after clip implantation. The aim of our study was to evaluate the mitral valve (MV) annular remodelling with MitraClip XTr. Between March 2018 and November 2018, 75 consecutive patients were enrolled. The population was divided in two groups: functional mitral regurgitation (FMR) and degenerative mitral regurgitation (DMR). The 3D MV datasets at baseline and immediately after the procedure were acquired and then analysed with semiautomatic MVQ software (QLAB Cardiac 3DQ v.10.0; Philips Medical Systems). The software provides the following parameters: annular diameters (antero-posterior, AP, and inter-commissural, IC), circumference, area, height and ellipsicity (IC/AP ratio as percentage); saddle-index, defined as annular height to IC diameter ratio was derived. The 3D post-processing was feasible in 54 patients (108 3D datasets): 28 had FMR (52%) and 26 had DMR (48%). An average of 1.8 clips per patient were implanted: 2 clips in 38 (70%), 1 clip in 14 (26%) and 3 clips in 2 (4%) patients. The position was central in 93% of the procedures. Results are reported in table 1. In the FMR group, a reduction in the AP diameter (p=0.001), an increase in both IC diameter (p=0.001) and annular ellipsicity (p<0.001) were observed. In the DMR group, an increase in annular ellipsicity (p=0,008) and in saddle-index (p<0.05) were observed. Table 1 Functional mitral regurgitation (N=28) Degenerative mitral regurgitation (N=26) Pre-clip Post-clip P-value Pre-clip Post-clip P-value IC diameter (mm) 39.3±4.2 41.9±4.1 0.001 40.9±6.5 41.8±5.8 0.257 AP diameter (mm) 32.8±4.6 30.4±3.2 0.001 32.6±4.8 31.7±4.5 0.199 Annular Height (mm) 5.1±1.8 5.4±1.8 0.336 4.8±1.9 5.7±2.2 0.026 3D circumference (mm) 122.7±15.1 123.5±11 0.718 123.5±19.0 124.0±17.1 0.812 3D area (mmq) 1128.0±280 1113.7±206 0.752 1160±346.7 1156.8±318.0 0.926 Annular ellipsicity (%) 121.5±12.2 138.5±11.8 0.0005 125.9±9.6 132.4±10.7 0.008 Saddle index 13.0±4 13.0±4 0.957 11.8±4.2 13.6±4.2 0.048 Our study demonstrates that the XTr implantation produces a MV annular remodelling both in FMR and DMR probably with different mechanisms. In FMR the MV annulus resulted more elliptical, wheras in DMR the geometrical modifications involve both the ellipsicity and the saddle-shape morphology.