mtCO1-based population structure and genetic diversity of Pacific oyster *Crassostrea gigas* populations acquired from two farms in South Korea

Since the early 1990s in South Korea, climatic and anthropogenic factors have incurred the reduction of the wild seeds of the Pacific oyster, Crassostrea gigas, which raised concerns about losing genetic diversity and accelerating genetic deterioration. We assessed the genetic diversity of C. gigas populations from two farms (Tongyeong and Gadeokdo) on the southern coast, where about 80% of the cultivated oysters in Korea are produced. Tongyeong showed slightly higher diversity than Gadeokdo, but both populations had a similar genetic structure characterized by low nucleotide diversity. Comparative haplotype analyses provided data supporting genetic features of the populations that include (1) weak genotype-locality relationship, (2) low levels of gene flow between populations, and (3) possible seasonal fluctuation of genetic variation within a population. Furthermore, the highly alike haplotype network patterns were observed between the wild and farm populations as well as among the populations in neighboring countries, which suggests that the genetic structure is conserved between wild and hatchery populations, and geographic proximity has minimal influence on the genetic composition

Design and Implementation of EMB System

The EMB(Electric Mechanical Brake) system is replacing the former hydrodynamic brake system. A brake system is a nonlinear system which applies a different compressive force depending on the position of the brake pad. The EMB system operates the brake by the motor instead of the hydrodynamic system. So the new design of brake caliper and the development of the motor controller and the invertor are needed. The gap between the pads shall be controlled exactly to operate an accurate force control. The new algorithm to compensate the pad abrasion and the disk abrasion is needed. In this paper, the mechanical part are designed to operate the brake and the EMB controller are designed and implemented with a motor controller and an inverter. The EMB controller model is verified by the MATLAB. The initialization algorithm is developed to compensate the pad abrasion and the backlash of the gear to make the same gap between the disk and the pad. The suggested algorithm detects the pad gap equally and the force depending on the pad gap is measured consistently

Large Eddy Simulation of flow and tracer transport in multichamber ozone contactors

Three-dimensional numerical analyses of flow and transport characteristics in two representative multichamber ozone contactor models with different chamber width were conducted using large eddy simulation (LES). Both time-averaged and instantaneous flow patterns suggest that the flow is characterized by the occurrence of large turbulent structures leading to extensive short-circuiting between chambers and internal recirculation inside the chambers. The flow is also found to be highly three-dimensional, as secondary vortices and recirculation zones develop. The simulation results further suggest that the hydrodynamics in ozone contactors can be improved by reducing the chamber width. The results of the LES are qualitatively verified using previously reported tracer test results obtained from laboratory experiments. The LES technique, applied to the ozone contactor flow and transport of a tracer for the first time, is expected to serve as a powerful tool for existing reactor flow diagnosis, reactor retrofitting as well as for new reactor design

Small Fermi pockets intertwined with charge stripes and pair density wave order in a kagome superconductor

The kagome superconductor family AV3Sb5 (A=Cs, K, Rb) emerged as an exciting platform to study exotic Fermi surface instabilities. Here we use spectroscopic-imaging scanning tunneling microscopy (SI-STM) and angle-resolved photoemission spectroscopy (ARPES) to reveal how the surprising cascade of higher and lower-dimensional density waves in CsV3Sb5 is intimately tied to a set of small reconstructed Fermi pockets. ARPES measurements visualize the formation of these pockets generated by a 3D charge density wave transition. The pockets are connected by dispersive q* wave vectors observed in Fourier transforms of STM differential conductance maps. As the additional 1D charge order emerges at a lower temperature, q* wave vectors become substantially renormalized, signaling further reconstruction of the Fermi pockets. Remarkably, in the superconducting state, the superconducting gap modulations give rise to an in-plane Cooper pair-density-wave at the same q* wave vectors. Our work demonstrates the intrinsic origin of the charge-stripes and the pair-density-wave in CsV3Sb5 and their relationship to the Fermi pockets. These experiments uncover a unique scenario of how Fermi pockets generated by a parent charge density wave state can provide a favorable platform for the emergence of additional density waves

Characteristics and correlations of leaf stomata in different Aleurites montana provenances.

Stomata are important indexes in studies of plant origin, evolution, and classification and are important organs in plant phylogenetic relationship studies. Nine Aleurites montana provenances were used in this study to examine stomatal density, stomatal area, stomatal perimeter, long axis length, and short axis length. The correlation and cluster analyses were conducted among the morphological parameters of the pores. The results showed that there were significant differences in different A. Montana provenances in terms of stomatal morphology parameters. The average stomatal density, stomatal area, stomatal perimeter, stomatal long axis length, and stomatal short axis length of each provenance was between 224.16-307.10 stomata/mm2, 80.42-99.76 μm, 36.39-41.32 μm, 15.89-18.44 μm, and 6.53-7.46 μm, respectively, and the coefficient of variation was between 9.18%-20.15%, 17.57%-33.77%, 9.31%-18.79%, 9.71%-18.48%, and 10.26%-21.57%, respectively. Correlation analysis shows that there was a significant negative correlation between stomatal density and stomatal shape parameters (stomatal area, stomatal perimeter, stomatal long axis, stomatal short axis) and there was a significant positive correlation between stomatal parameters. There was no significant correlation between geographical environment factors and stomatal characteristics. There is a close relationship between stomatal morphology and stomatal conductance whereby dense small stomata can quickly adapt to changes in the environment; considering the characteristics A. montana stomata in terms of stomatal stability and ability to adapt to the environment, the Jianyang, Zhenghe, Fuding, Shaxian provenances were identified as being more suitable for planting at different sites. This study provides a theoretical basis for the genetic improvement and breeding of high quality A. montana provenances

Modeling aspects of flow and solute transport simulations in water disinfection tanks

Water disinfection tanks such as chlorine and ozone contactors typically consist of multiple compartments featuring a serpentine flow pattern. Due to the complex hydrodynamics, the design and optimization of these tanks are often carried out by employing computational fluid dynamics (CFD) simulations. The present study demonstrates the influence of certain modeling aspects when the widely used Reynolds-Averaged Navier Stokes (RANS) based CFD approach to predict hydrodynamics and disinfection performance is employed. Three different contact tank geometries are examined numerically using RANS. The time-averaged velocity predictions are reasonably accurate when compared to validation data. However, in baffled contact tanks, the time-averaged flow differs quite significantly from the instantaneous flow, with the consequence that RANS-based models require careful calibration of the turbulent mixing parameter, i.e., the turbulent Schmidt number, when computing transport of solutes

The effect of baffle spacing on hydrodynamics and solute transport in serpentine contact tanks

The effect of baffle spacing on the hydrodynamics and transport characteristics in a scaled variable-baffle-spacing contact tank is investigated by employing large-eddy simulation. Simulated solute transport is quantitatively validated by comparing simulated and measured residence time distribution curves, for which good agreement is found. The flow in serpentine disinfection tanks is dominated by a path of high streamwise velocities, a so-called short-circuiting path, which is almost constant in width regardless of the baffle spacing. In addition, large-scale turbulent vortices are shed from baffle edges and their size and dynamics depend on the spacing between subsequent baffles. The transport in serpentine-flow contact tanks is advection dominated and transport occurs mainly along the short-circuiting path. Wider compartments feature large recirculation zones with instantaneous vortices entraining solutes into these zones and thereby increasing residence times. Contact tanks with wide compartments suffer from severe short-circuiting and internal recirculation. This is directly reflected in hydraulic efficiency indicators

Development of model output statistics based on the least absolute shrinkage and selection operator regression for forecasting next-day maximum temperature in South Korea

Regression models for model output statistics (MOS) based on least absolute shrinkage and selection operator methods were developed to forecast next-day maximum surface air temperature (TMAX) during the warm season in South Korea. The forecast fields from the operational numerical weather prediction (NWP) system of the Korean Meteorological Administration for global and local forecasts and the observed TMAX data in 225 observation stations were used as input variables for the MOS. The training period was July and August (JA) from 2015 to 2018, and the regression models were tested using data from JA 2019. As a result of hindcasting for the test period, the MOS models performed significantly better for next-day TMAX forecasting over South Korea than the numerical models during JA 2019. The mean TMAX errors were reduced by over 1 degrees C in MOSs compared to those in the numerical models. However, the TMAX forecast performance was generally lower in the higher-resolution NWP Local Data Assimilation and Prediction System (LDAPS)-based MOS (LMOS) than in the lower-resolution NWP Global Data Assimilation and Prediction System (GDAPS)-based MOS. This pattern was dominant when LDAPS simulated the TMAX more accurately than average. In particular, the random TMAX error of LDAPS was larger than that of GDAPS during the training period, and a positive random error of TMAX was magnified in LMOS. Because the other predictors forecasted from LDAPS can be associated with lower TMAX forecast performance of LMOS, in addition to TMAX effects as a predictor, a new MOS was developed using both LDAPS and GDAPS outputs. The forecast accuracy was improved by up to 0.3 degrees C when the forecast fields from the GDAPS substituted several LMOS predictors, even though TMAX was the primary predictor for LMOS