Boussinesq Modelling of Waves and Currents in the Presence of Submerged Detached/Discontinuous Breakwaters

The effect of beach configurations with the main focus on the detached submerged breakwater on shoreline currents is investigated numerically. The Boussinesq equations are used to model the beach with a constant slope, continuous submerged breakwater, and discontinuous/detached submerged breakwater. Our numerical simulation results show that the transient rip currents are generated near the shoreline at the beach with constant slope while the continuous submerged breakwater structure creates a calm beach area along the shoreline. The presence of the gap in submerged breakwater changes the currents along the shoreline by generating rip currents with two pairs of vortices. One pair of vorticities, located around the gap, damage the breakwater by transmitting sediments along the breakwater foundation and eroding its surface. The second pair, created near the shoreline, erodes the shoreline due to sediment transportation and leads to a dangerous and unsafe situation for swimmers. The rip current creates five main critical areas with the maximum velocity towards the shoreline and offshore. The first set of three areas (numbered 1, 2, 3) has an approximately average velocity of 1-1.25 m/s towards the shoreline. One of these areas (numbered 2) is located close to the shoreline and the other two (numbered 1 and 3) are found to occur near the edge of the detached part of the breakwater. The second set of the two areas (numbered by 4 and 5) has the average velocity that is higher than 2.1 m/s towards the offshore and is located at the beginning part of the rip neck. An approximately linear relationship between the returning velocity and the gap length is observed. As the gap length decreases the location of the areas (numbered 4 and 5) gets closer to the center of the gap. Our simulations indicate that the return velocity towards the offshore increases at the gap center while the gap length decreases. Furthermore, the velocity profiles have a sharp jump for gap length that is approximately smaller than 80 m. Also, the return velocity at the gap center is related to the height of the breakwater. The breakwater that is higher (the breakwater height d = 4.2 m) damps wave energy more than shorter breakwater and the return velocity decreases for this structure. For smaller heights (d = 3.7 and 3.2) damping is nearly the same and the returning flow varies depending on the available space through the gap. Specifically, the return velocity for d = 3.7 is higher than that for d = 3.2. The numerical results presented herein suggest that aggressive rip currents are generated in the case of detached submerged breakwater beach configurations

Analogue mouse pointer control via an online steady state visual evoked potential (SSVEP) brain-computer interface

The steady state visual evoked protocol has recently become a popular paradigm in brain–computer interface (BCI) applications. Typically (regardless of function) these applications offer the user a binary selection of targets that perform correspondingly discrete actions. Such discrete control systems are appropriate for applications that are inherently isolated in nature, such as selecting numbers from a keypad to be dialled or letters from an alphabet to be spelled. However motivation exists for users to employ proportional control methods in intrinsically analogue tasks such as the movement of a mouse pointer. This paper introduces an online BCI in which control of a mouse pointer is directly proportional to a user's intent. Performance is measured over a series of pointer movement tasks and compared to the traditional discrete output approach. Analogue control allowed subjects to move the pointer faster to the cued target location compared to discrete output but suffers more undesired movements overall. Best performance is achieved when combining the threshold to movement of traditional discrete techniques with the range of movement offered by proportional control

Bridging sd1 molecular knowledge with recent breeding strategies for the improvement of traditional rice varieties - a japonica case-study

The rice semidwarfing gene, sd1, also known as the “green revolution gene”, has been studied intensively due to its contribution to the increase of crop production. Although sd1 breeding was extensively applied since the 1960s, the recent advances in the molecular basis of this gene alloweddesigning a more precise breeding strategy - marker assisted backcrossing (MAB) - to track sd1 introgression in two traditional rice varieties. For selection of sd1 plants we first confirmed the efficiency of specific markers based on Os200 x 2 gene sequence. Background selection was alsoperformed with the help of microsatellites markers (SSR) and a total of 7 breeding lines were recovered containing a higher percentage of recurrent parent genome (RPG). Analysis of Covariance (ANCOVA) using mean progenitor plant height as covariate was performed to compare several agronomic and quality-related parameters in two different environments. The results suggest that plant height differs significantly between the two environments F(1, 220) = 155.336; p < 0.001. From the total variability ofplant height we could conclude that 73% is due to the genotype, while 10.4% depends on the environment. In addition, the percentage of RPG seems negatively correlated with plant height (p < 0.005). MAB and background selection thus revealed as useful tools to assist breeding forsemidwarfism in traditional rice varieties

A theorem for a fluid Stokes flow

A sphere theorem for non-axisymmetric Stokes flow of a viscous fluid of viscosity μe past a fluid sphere of viscosity μi is stated and proved. The existing sphere theorems in Stokes flow follow as special cases from the present theorem. It is observed that the expression for drag on the fluid sphere is a linear combination of rigid and shear-free drags

The Epidemiology and Outcomes of Percutaneous Coronary Intervention Before High‐Risk Noncardiac Surgery in Contemporary Practice: Insights From the Blue Cross Blue Shield of Michigan Cardiovascular Consortium (BMC2) Registry

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139074/1/jah3534.pd