dual rotation
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2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zehba Raizah ◽  
Abdelraheem M. Aly

AbstractThe time-fractional derivative based on the Grunwald–Letnikove derivative of the 2D-ISPH method is applying to emulate the dual rotation on MHD natural convection in a hexagonal-shaped cavity suspended by nano-encapsulated phase change material (NEPCM). The dual rotation is performed between the inner fin and outer hexagonal-shaped cavity. The impacts of a fractional time derivative $$\alpha$$ α $$\left( {0.92 \le \alpha \le 1} \right)$$ 0.92 ≤ α ≤ 1 , Hartmann number Ha $$\left( {0 \le Ha \le 80} \right)$$ 0 ≤ H a ≤ 80 , fin length $$\left( {0.2 \le L_{Fin} \le 1} \right)$$ 0.2 ≤ L Fin ≤ 1 , Darcy parameter Da $$\left( {10^{ - 2} \le Da \le 10^{ - 4} } \right)$$ 10 - 2 ≤ D a ≤ 10 - 4 , Rayleigh number Ra $$\left( {10^{3} \le Ra \le 10^{6} } \right)$$ 10 3 ≤ R a ≤ 10 6 , fusion temperature $$\theta_{f}$$ θ f $$\left( {0.05 \le \theta_{f} \le 0.8} \right)$$ 0.05 ≤ θ f ≤ 0.8 , and solid volume fraction $$\varphi$$ φ $$\left( {0 \le \varphi \le 0.06} \right)$$ 0 ≤ φ ≤ 0.06 on the velocity field, isotherms, and mean Nusselt number $$\overline{Nu}$$ Nu ¯ are discussed. The outcomes signaled that a dual rotation of the inner fin and outer domain is affected by a time-fractional derivative. The inserted cool fin is functioning efficiently in the cooling process and adjusting the phase change zone within a hexagonal-shaped cavity. An increment in fin length augments the cooling process and changes the location of a phase change zone. A fusion temperature $$\theta_{f}$$ θ f adjusts the strength and position of a phase change zone. The highest values of $$\overline{Nu}$$ Nu ¯ are obtained when $$\alpha = 1$$ α = 1 . An expansion in Hartmann number $$Ha $$ Ha reduces the values of $$\overline{Nu}$$ Nu ¯ . Adding more concentration of nanoparticles is improving the values of $$\overline{Nu}$$ Nu ¯ .


Author(s):  
Hongfeng You ◽  
Long Yu ◽  
Shengwei Tian ◽  
Weiwei Cai

AbstractTo obtain more semantic information with small samples for medical image segmentation, this paper proposes a simple and efficient dual-rotation network (DR-Net) that strengthens the quality of both local and global feature maps. The key steps of the DR-Net algorithm are as follows (as shown in Fig. 1). First, the number of channels in each layer is divided into four equal portions. Then, different rotation strategies are used to obtain a rotation feature map in multiple directions for each subimage. Then, the multiscale volume product and dilated convolution are used to learn the local and global features of feature maps. Finally, the residual strategy and integration strategy are used to fuse the generated feature maps. Experimental results demonstrate that the DR-Net method can obtain higher segmentation accuracy on both the CHAOS and BraTS data sets compared to the state-of-the-art methods.


2021 ◽  
Vol 11 (9) ◽  
pp. 3917
Author(s):  
Francisco Javier Gómez-Uceda ◽  
Isabel Maria Moreno-Garcia ◽  
Álvaro Perez-Castañeda ◽  
Luis Manuel Fernández-Ahumada

Solar tracking is an efficient strategy to increase the radiative capture of photovoltaic collectors. Within the multiple efforts made in recent decades to improve the production of these facilities, various works have studied solutions to optimize the number of rotation axes (single or dual rotation axes), the degree of collector coverage, the distances between trackers, the geometric arrangement of trackers or the minimization of shading between collectors. However, although in this type of installation it is common to find collectors with geometric shapes other than rectangles, no studies on the influence of the shape of the collectors on the radiative incidence are found in the literature. In this connection, the present work systematically addresses the study of incident solar radiation in photovoltaic installations with dual-axis trackers with collectors of different geometric shapes. By means of the exhaustive study, the conclusion is drawn that, for dual-axis photovoltaic installations with an optimal tracking strategy, the main variables that influence the annual radiative incidence are the spacing between collectors, the coverage ratio (GCR), and the collector surface, while the type of arrangement of collectors and the shape of these do not show predictive values.


2020 ◽  
Vol 267 ◽  
pp. 105503 ◽  
Author(s):  
Xiaoming Liu ◽  
Yanfeng Song ◽  
Zhao Xia ◽  
Renpeng Chen

Author(s):  
I. P. Popov ◽  

In this paper it is found that just as the result of composition of two uniform rectilinear motions is uniform rectilinear motion, the result of composition of two uniform one-way rotational motions is also uniform rotational motion. Basically generalization of Galileo relativity principle is presented on non-accelerated rotational motion. In this connection seven theorems having five corollaries have been proven. A hodograph in case of composition of two uniform oppositely directed rotational motions proves to be an ellipse. In particular case the ellipse can degenerate into a straight line segment. Characteristics of elliptical hodograph are determined, including large and small semi-axes, roots of characteristic equation, eccentricity, foci, the angle of the axes. The reverse problem is solved - determination of rotation speed by type of hodograph, including elliptical and circular. In composition of two asynchronous (multiple) rotations hodographs can be by type of a limacon, resembling Pascal’s limacon. The condition of occurrence of a limacon hodograph loop is found out. The practical aspect of the theme is determined by the fact that in milling cutter drives in machines for cleaning of large diameter pipes and many mechanisms (multi inert oscillator, planetary gear) summation of rotational motions is realized, and a hodograph shape is useful information while development of similar devices.


Plant Disease ◽  
2019 ◽  
Vol 103 (4) ◽  
pp. 729-736 ◽  
Author(s):  
Achour Amiri ◽  
Adrian I. Zuniga ◽  
Leandro G. Cordova ◽  
Natalia A. Peres

Botrytis fruit rot (BFR), caused by the necrotrophic fungus Botrytis cinerea, is the most important disease of strawberry and is mainly controlled by applications of fungicides from multiple chemical groups. To develop more effective and sustainable BFR management programs, field trials were conducted to evaluate the efficacy of fluopyram and penthiopyrad, two newly registered succinate dehydrogenase inhibitors (SDHIs), rotated or tank mixed with the multisites thiram and captan or the single-sites fludioxonil and fenhexamid. The treatments were applied at two different strawberry fields during the 2013–14 and 2014–15 seasons. Overall, tank mixtures of fluopyram and penthiopyrad increased yield and reduced BFR better than rotations with the same fungicides. The multisite thiram tank mixed with fluopyram reduced BFR incidence by 63 to 86% versus 56 to 84% when the two fungicides were rotated. Thiram tank mixed with penthiopyrad reduced BFR incidence by 55 to 72% versus 42 to 66% when rotated. Captan rotated or tank mixed with fluopyram had a positive effect on yield and BFR incidence, whereas the combination of captan with penthiopyrad had negative impacts. Similarly, the single-site fenhexamid had significant positive impacts when rotated or tank mixed with fluopyram but resulted in poor BFR control when combined with penthiopyrad. The rotation of fludioxonil with both SDHIs had a significant positive effect, although its combination with fluopyram was more effective. The multirotation consisting of both SDHIs and different multi- and single-site fungicides did not provide a greater efficacy than the dual rotation or tank-mixture programs. Our findings suggest more scrutiny is needed when recommending tank-mixture or rotation partners for new fungicides to ensure compatibility and enhanced BFR management. Future recommendations should emphasize the importance of such selections at an early stage for delaying fungicide resistance development and extending the lifespan of at-risk fungicides.


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