2,294 research outputs found
Analysis of Slab and Slab Heater Cover in a Compact Endless Cast and Rolling Mill Process using Finite Element Methods
Compact Endless cast and rolling Mill (CEM) processes were developed and used to fabricate steel products such as steel slabs. However, the coiling furnace in this process was very expensive, so a new layout was suggested. As the coiling furnace was removed, the interval among the slab heaters had to be increased. This led to a temperature drop in the slab. The temperature distribution of the slab impacts quality, so new layout was developed. This paper presents a Finite Element Method (FEM) simulation of thermal behavior in the slab employing slab heater covers. All of the simulation results were verified by comparing them with experimental results. The slab moving distance at which the temperature was saturated during the process was determined to consider the steady-state and analyze the temperature distribution of the slab and slab heater. Those results revealed that the efficiency of heat conservation increased by more than 50% using the slab heater cover. Finally, a sensitivity analysis of the slab heater cover was conducted with respect to the cover design. The effects of insulator thickness, the gap distance between the slab and cover, and material parameters such as density, and specific heat were investigated to optimize the design of the slab heater cover to produce the best quality slab.11Ysciescopuskc
Room-temperature polariton lasing in quantum heterostructure nanocavities
Controlling light-matter interactions in solid-state systems has motivated
intense research to produce bosonic quasi-particles known as
exciton-polaritons, which requires strong coupling between excitons and cavity
photons. Ultra-low threshold coherent light emitters can be achieved through
lasing from exciton-polariton condensates, but this generally requires
sophisticated device structures and cryogenic temperatures. Polaritonic
nanolasers operating at room temperature lie on the crucial path of related
research, not only for the exploration of polariton physics at the nanoscale
but also for potential applications in quantum information systems, all-optical
logic gates, and ultra-low threshold lasers. However, at present, progress
toward room-temperature polariton nanolasers has been limited by the thermal
instability of excitons and the inherently low quality factors of nanocavities.
Here, we demonstrate room-temperature polaritonic nanolasers by designing
wide-gap semiconductor heterostructure nanocavities to produce thermally stable
excitons coupled with nanocavity photons. The resulting mixed states of
exciton-polaritons with Rabi frequencies of approximately 370 meV enable
persistent polariton lasing up to room temperature, facilitating the
realization of miniaturized and integrated polariton systems
Meibomian Epithelioma of the Lower Eyelid in a Thoroughbred Horse
A 9-year old, castrated male, thoroughbred horse presented for a left lower eyelid mass with ocular signs of mucopurulent discharge, conjunctival hyperemia and ocular discomfort. On physical examination, there was no other abnormality. Surgically, the mass arising from the inner surface of left lower eyelid was excised and examined histopathologically. Microscopically, the eyelid mass exhibited neoplastic basaloid cells forming irregular cell masses of variable size separated by thin fibrous tissues. The basaloid cells showed mildly pleomorphic and undifferentiated appearances with prominent oval nuclei and scant cytoplasm. Poorly differentiated meibocytes were observed occasionally in the periphery regions of the cell masses suggesting the mass of lower eyelid originated from meibomian glands. Based on histopathological observation, the present case was diagnosed as an equine meibomian epithelioma in the lower eyelid. To the authorās knowledge, the present case is the first report of equine meibomian epithelioma in veterinary literatures
Structural safety inspection of reinforced concrete structures considering failure probabilities of structural members
Regular safety inspections of existing reinforced concrete (RC) structures are required according to the regulations and criteria set by each country. In South Korea, the safety inspection regulations provided by the Korea Infrastructure Safety and Technology Corporation (KISTEC) are followed. These regulations were developed based on fuzzy theory to avoid subjective decisions, and provide standardized deterioration grades for member types, floors, and the entire structure. However, the safety inspection regulation by the KISTEC often provides unconservative evaluation results. In particular, as the importance factors of beam and slab members are set lower than those of other members, there are cases in which deteriorations occurring in beams and slabs are not properly reflected in the floor level evaluation. In this study, to overcome such limitations, case studies were carried out and modified importance factors for structural member types were proposed considering the failure probabilities of each member type based on the reliability theory. The importance modification factor was calculated based on the strength ratio of structural members so that the more dangerous the members are, the more impact they give on the evaluation. Overall, compared to the KISTEC method, the proposed method provided conservative but practical assessment results, and it was found that the proposed importance factors can be very useful to properly reflect the effects of damaged members on the deterioration status evaluation of the floors and the entire structure
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