Asymmetric Flow Control in a Slab Mold through a New Type of Electromagnetic Field Arrangement

This research aims to investigate the control effect of asymmetric flow in a slab mold using a novel magnetic field arrangement: freestanding adjustable combination electromagnetic brake (FAC-EMBr). Three scenarios (submerged entry nozzle moves to the narrow face, wide face of the slab mold, and rotates 10°) were studied using three-dimensional numerical simulation. The results show that the magnetic field generated by the FAC-EMBr system can effectively cover three key zones in mold and that the magnetic flux density in the zone cover by a vertical magnetic pole can be adjusted according to the actual flow condition. The FAC-EMBr can effectively improve the asymmetric flow in a mold and near the narrow surface caused by the asymmetric arrangement of the nozzle and can effectively inhibit the occurrence of the flow deviation phenomenon and stabilize the steel/slag interface fluctuation. At the same time, FAC-EMBr has obvious inhibition effects on the surface velocity and can optimize the asymmetric distribution of the surface velocity and the upper reflux velocity caused by the asymmetric arrangement of the nozzle. This study can provide theoretical evidence for the development and utilization of a new electromagnetic brake technology

Characterization, phylogeny, alternative splicing and expression of Sox30 gene

<p>Abstract</p> <p>Background</p> <p>Members of the Sox gene family isolated from both vertebrates and invertebrates have been proved to participate in a wide variety of developmental processes, including sex determination and differentiation. Among these members, <it>Sox30 </it>had been considered to exist only in mammals since its discovery, and its exact function remains unclear.</p> <p>Results</p> <p><it>Sox30 </it>cDNA was cloned from the Nile tilapia by RT-PCR and RACE. Screening of available genome and EST databases and phylogenetic analysis showed that <it>Sox30 </it>also exists in non-mammalian vertebrates and invertebrates, which was further supported by synteny analyses. Tissue expression in human, mouse and tilapia suggested that <it>Sox30 </it>was probably a gonad-specific gene, which was also supported by the fact that <it>Sox30 </it>EST sequences were obtained from gonads of the animal species. In addition, four alternatively spliced isoforms were isolated from tilapia gonad. Their temporal and spatial expression patterns during normal and sex reversed gonadal development were investigated by RT-PCR and <it>in situ </it>hybridization. Our data suggest that expressions of <it>Sox30 </it>isoforms are related to stage and phenotypic-sex, observed in the germ cells of male gonad and in somatic cells of the female gonad.</p> <p>Conclusions</p> <p><it>Sox30 </it>is not a gene only existed in mammals, but exists widely throughout the animal kingdom as supported by our bioinformatic, phylogenetic and syntenic analyses. It is very likely that <it>Sox30 </it>is expressed exclusively in gonads. Expression analyses revealed that <it>Sox30 </it>may be involved in female and male gonadal development at different stages by alternative splicing.</p

Parallel Architecture Design for OpenVX Kernel Image Processing Functions

Although the traditional programmable processors are highly flexible, their processing speed and perfor-mance are inferior to the application specific integrated circuit (ASIC). Image processing is often a diverse, intensive and repetitive operation, so the processor must balance speed, performance and flexibility. OpenVX is an open source standard for preprocessing or auxiliary processing of image processing, graph computing and deep learning applications. Aiming at the kernel visual function library of OpenVX 1.3 standard, this paper designs and implements a programmable and extensible OpenVX parallel processor. The architecture adopts an application specific instruction processor (ASIP). After analyzing and comparing the topological characteristics of various interconnection networks, the backbone of the ASIP chooses the hierarchically cross-connected Mesh+ (HCCM+) with outstanding performance, and processing element (PE) is set at network nodes. PE array is constructed to support dynamic configuration, and a parallel processor is designed to realize programmable image processing based on efficient routing and com-munication. The proposed architecture is suitable for data parallel computing and emerging graph computing. The two computing modes can be configured separately or mixed. The kernel visual function and graph computing model are mapped to the parallel processor respectively to verify the two modes and compare the image processing speed under different PE numbers. The results show that OpenVX parallel processor can complete the mapping and linear speedup of kernel functions and high complexity graph calculation model. The average speedup of scheduling 16 PEs to various functions is approximately 15.0375. When implemented on an FPGA board with a 20 nm XCVU440 device, the prototype can run at a frequency of 125 MHz

Multiple antiferromagnetic phases and magnetic anisotropy in exfoliated CrBr3_3 multilayers

In twisted two-dimensional (2D) magnets, the stacking dependence of the magnetic exchange interaction can lead to regions of ferromagnetic and antiferromagnetic interlayer order, separated by non-collinear, skyrmion-like spin textures. Recent experimental searches for these textures have focused on CrI$_3$, known to exhibit either ferromagnetic or antiferromagnetic interlayer order, depending on layer stacking. However, the very strong uniaxial anisotropy of CrI$_3$ disfavors smooth non-collinear phases in twisted bilayers. Here, we report the experimental observation of three distinct magnetic phases -- one ferromagnetic and two antiferromagnetic -- in exfoliated CrBr$_3$ multilayers, and reveal that the uniaxial anisotropy is significantly smaller than in CrI$_3$. These results are obtained by magnetoconductance measurements on CrBr$_3$ tunnel barriers and Raman spectroscopy, in conjunction with density functional theory calculations, which enable us to identify the stackings responsible for the different interlayer magnetic couplings. The detection of all locally stable magnetic states predicted to exist in CrBr$_3$ and the excellent agreement found between theory and experiments, provide complete information on the stacking-dependent interlayer exchange energy and establish twisted bilayer CrBr$_3$ as an ideal system to deterministically create non-collinear magnetic phases

Optimal configuration of a two-heat-reservoir heat-engine with heat-leak and finite thermal-capacity

Based on a model of a two-heat-reservoir heat-engine cycle with a finite high-temperature source and bypass heat-leak, in which the maximum work output can be obtained under a given cycle time is determined with the considerations of heat-leak, finite heat-capacity high-temperature source and infinite heat-capacity low-temperature heat-sink with another linear heat-transfer law Q [is proportional to] [Delta](T-1). The heat-engine cycles considered are: (1) infinite low-and high-temperature reservoirs without heat-leak; (2) infinite low- and high-temperature reservoirs with heat-leak; (3) finite high-temperature source and infinite low-temperature sink without heat-leak and (4) finite high-temperature source and infinite low-temperature sink with heat-leak. It is assumed that the heat-transfer between the working fluid and the reservoirs obeys another linear heat-transfer law, i.e., the linear phenomenological heat-transfer law, Q [is proportional to] [Delta](T-1). It is shown that the existence of heat-leak does not affect the configuration of a cycle with an infinite high-temperature source. The finite heat-capacity of the high-temperature source without heat-leak makes the cycle a generalized Carnot heat-engine cycle. There exists a great difference of the cycle configurations for the finite high-temperature source with heat-leak and the former three cases. Moreover, the relations between the optimal power-output and the efficiency of the former three configurations are derived, and they show that the heat-leak affects the power versus efficiency characteristics of the heat-engine cycles.Finite-time thermodynamics Optimal configuration heat-engine Linear phenomenological heat-transfer law heat-resistance heat-leak

Optimal allocation of heat-exchanger area for refrigeration and air-conditioning plants

The performance of the Carnot cycle and a vapor-compression refrigeration cycle can be optimized by the choice of a heat-exchanger area between the evaporator and the condenser. In this paper, the analytical expressions for the optimal allocation of heat-exchanger area for the endoreversible and irreversible Carnot cycles with constant- and variable-temperature heat-reservoirs are derived. The optimal values for real vapor-compression cycles are obtained by numerical analysis. The results can guide the evaluation of existing refrigeration and air-conditioning plants or influence design practice for future plants.

Heat-conduction optimization based on constructal theory

An analysis of the "tree-like network" construct method is presented. The high effective-conduction channel distribution has been optimized, without the premise that the new-order assembly construct must be assembled by the optimized last-order construct. The "tree-like network" construct method is faultiness. A more optimal construct is obtained, and when the thermal conductivities and the proportion of the two heat-conduction materials are constants, the limit of the minimum-heat resistance is derived. These conclusions can be used as a guide for engineering applications.Constructal theory " Tree-like network" construct method High effective-conduction channel distribution Generalized thermodynamic optimization

Thermo-economics for endoreversible heat-engines

The thermoeconomics of endoreversible heat engines has been studied based on the linear phenomenological heat-transfer law [i.e., the heat flux Q [is proportional to] [Delta](1/T), where T is the absolute temperature]. Analytical formulae for profit, the maximum profit and the corresponding efficiency are derived.Endoreversible thermodynamics Endoreversible thermo-economics Linear phenomenological heat-transfer law Optimization