• 한국어병학회지
• /
• 제34권1호
• /
• pp.63-70
• /
• 2021

As a part of research to elucidate the pathogenesis of so called Soft Tunic Syndrome(STS), that caused mass mortalities in the cultured sea squirts, Halocynthia roretzi, the epidemiological and pathological analysis were done to both clinically normal and diseased groups of the farms of Tongyoung and Geoje coastal areas in southeast sea from February to July, 2008. In the histological finding of the tunic, most of individuals showed tunic softness syndromes that included the disarrangement and destruction of tunic fiber with the simultaneous presence of flagellates-like cells, recently suspected as main agents of tunic softness syndromes. Simultaneously, the intensive degenerative changes of the skeletal muscle of diseased sea squirts were recognized. The changes were characterized with the hyalinization and condensation of muscle fibril and hemocytic infiltration in the muscle fibers. Those were thought to be a kind of typical Zenker's necrosis as in the skeletal muscle of higher vertebrates. Besides of the diseased sea squirts, Zenker's necrosis of skeletal muscles were seen in the normal ones. Epidemiological inquiry for diseased groups revealed that the higher incidences of tunic softness syndrome were recorded in the fast growing groups and in the sites presuming the organic pollution. And Higher malondialadehyde(MDA) and glutathione peroxidase(GPx) activity were detected in the groups showing STS. Those results suggested that Zenker's necrosis of body muscles was a kind of"nutritional myopathy" by oxidative stress. Conclusively, it was considered that Zenker's necrosis of body muscles gives an important clue for elucidating pathogenesis of STS of cultured squirts. And it seems that the necrosis were caused by the oxidative stress to body muscle during abnormal rapid growth of sea squirts.

• 대한화상학회지
• /
• 제23권1호
• /
• pp.7-12
• /
• 2020

Purpose: Due to rapid changes in the industrial structure in last decade, the wider various types of chemical agents were introduced. Burn surgeons should be well-informed with rapid changes of chemical burns. We present the recent incidence trends of causing agents of chemical burns. Methods: From 2010 to 2019, 92 chemical burn victims were included in this study. A retrospective study was made about the type, distribution and incidence of the causing agents of chemical burns. Initial treatments of most chemical burn wounds are copious saline irrigation by tap water, except hydrofluoric acid burn cases managed by 10% calcium gluconate injection. In alkali chemical burns on extremity, if thin eschars appear in postburn 2~3 days, acute early surgical escharectomy and split thickness skin graft were done. Results: More than 9 types of major chemicals causing chemical burns were surveyed, and the most common causing agent of chemical burns was Hydrofluoric acid (23.9%) followed by Acetic acid (19.6%) and Sodium hydroxide (8.7%). Conclusion: From 2010 to 2019, changes in the causing agent of chemical burns are that the types of major causing agents of chemical burns have increased and the distribution and incidence of causing agents have changed compared to previous reports. According to this study, more than 9 types of major chemicals causing chemical burns were surveyed, and the most common causing agent of chemical burns was Hydrofluoric acid (23.9%) followed by Acetic acid, Sodium hydroxide.

• Journal of Cardiovascular Imaging
• /
• 제31권2호
• /
• pp.71-82
• /
• 2023

BACKGROUND: Cardiac magnetic resonance fingerprinting (cMRF) enables simultaneous mapping of myocardial T1 and T2 with very short acquisition times. Breathing maneuvers have been utilized as a vasoactive stress test to dynamically characterize myocardial tissue in vivo. We tested the feasibility of sequential, rapid cMRF acquisitions during breathing maneuvers to quantify myocardial T1 and T2 changes. METHODS: We measured T1 and T2 values using conventional T1 and T2-mapping techniques (modified look locker inversion [MOLLI] and T2-prepared balanced-steady state free precession), and a 15 heartbeat (15-hb) and rapid 5-hb cMRF sequence in a phantom and in 9 healthy volunteers. The cMRF_5-hb sequence was also used to dynamically assess T1 and T2 changes over the course of a vasoactive combined breathing maneuver. RESULTS: In healthy volunteers, the mean myocardial T1 of the different mapping methodologies were: MOLLI 1,224 ± 81 ms, cMRF_15-hb 1,359 ± 97 ms, and cMRF_5-hb 1,357 ± 76 ms. The mean myocardial T2 measured with the conventional mapping technique was 41.7 ± 6.7 ms, while for cMRF_15-hb 29.6 ± 5.8 ms and cMRF_5-hb 30.5 ± 5.8 ms. T2 was reduced with vasoconstriction (post-hyperventilation compared to a baseline resting state) (30.15 ± 1.53 ms vs. 27.99 ± 2.07 ms, p = 0.02), while T1 did not change with hyperventilation. During the vasodilatory breath-hold, no significant change of myocardial T1 and T2 was observed. CONCLUSIONS: cMRF_5-hb enables simultaneous mapping of myocardial T1 and T2, and may be used to track dynamic changes of myocardial T1 and T2 during vasoactive combined breathing maneuvers.

• 소성∙가공
• /
• 제19권3호
• /
• pp.152-159
• /
• 2010

Rapid mold heating has been recent issue to enable the injection molding of thin-walled parts or micro/nano structures. High-frequency induction is an efficient way to heat mold surface by electromagnetic induction in a non-contact manner, and has been recently applied to the injection molding due to its capability of rapid heating and cooling of mold surface. The present study covers a three-dimensional finite element analysis to investigate heating efficiency and structural safety of the induction heating process of an injection mold. To simulate the induction heating process, an integrated simulation method is proposed by effectively connecting an electromagnetic field analysis, a transient heat transfer analysis and a thermal stress analysis. The estimated temperature changes are compared with experimental measurements for various types of induction coil, from which heating efficiency according to the coil shape is discussed. The resulting thermal stress distributions of the mold plate for various types of induction coils are also evaluated and discussed in terms of the structural safety.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2017년도 춘계 학술논문 발표대회
• /
• pp.169-170
• /
• 2017

Recently in the construction industry there has been an increasing use of increasing replacement of cement with blast furnace slag cement(BS), an industrial by-product, to reduce environment load and production costs, and other increasing uses of BS cement. However in the case of BS being delivered in RMC factories, only score reports submitted when the are delivered are relied upon and ways to test the quality of fineness is inadequate. Therefore this study gave many changes to various cements and BS fineness to test the variations of BS as a cement, then used the correlation between this and the density value in the Hydrometer method to test the possibility for rapid appraisal of quality fineness of BS cement. Results showed that if the one fifth graph of the density and fineness correlation were to be used, a rapid appraisal of BS cement fineness quality would be possible.

• Applied Science and Convergence Technology
• /
• 제26권6호
• /
• pp.208-213
• /
• 2017

Flexible opto-electronic devices are developed on the insulating layer deposited stainless steel (STS) substrates. The silicon dioxide ($SiO_2$) material as the diffusion barrier of Fe and Cr atoms in addition to the electrical insulation between the electronic device and STS is processed using the plasma enhanced chemical vapor deposition method. Noble silver (Ag) films of approximately 100 nm thickness have been formed on $SiO_2$ deposited STS substrates by E-beam evaporation technique. The films then were annealed at $650^{\circ}C$ for 20 min using the rapid thermal annealing (RTA) technique. It was investigated the variation of the surface morphology due to the interaction between Ag films and $SiO_2$ layers after the RTA treatment. The results showed the movement of Si atoms in silver film from $SiO_2$. In addition, the structural investigation of Ag annealed at $650^{\circ}C$ indicated that the Ag film has the material property of p-type semiconductor and the bandgap of approximately 1 eV. Also, the films annealed at $650^{\circ}C$ showed reflection with sinusoidal oscillations due to optical interference of multiple reflections originated from films and substrate surfaces. Such changes can be attributed to both formation of $SiO_2$ on Ag film surface and agglomeration of silver film between particles due to annealing.

• 대한안전경영과학회:학술대회논문집
• /
• 대한안전경영과학회 2010년도 추계학술대회
• /
• pp.507-516
• /
• 2010

Product liability as a process has developed significantly in the United Kingdom and the United States of America. The safety of the product becomes one of the most important elements in modern corporate management. The rapid introduction of product liability has recently been a prevalent phenomenon, as global changes arising from rapid development in science and the economy have resulted in a highly interconnected world economy. This thesis was established, based on current literature and business consulting cases in the position of companies, and is one of the operating subjects in a system for legal responsibility in manufactured products.

• 한국기계가공학회지
• /
• 제14권2호
• /
• pp.121-126
• /
• 2015

In this research, a tool was developed for the rapid performance of three-dimensional finite element analysis (3D FEA) of a machine tool spindle system made of a shaft and bearings. It runs the FEA with data, such as the bearing stiffness and the coordinates of the points, to define the section of the shaft, bearing positions, and cutting point. developed for the spindle system and then implemented with the tool using an object-oriented programing technique that allows the use of the objects of the CAD system used in this research. Graphic user interfaces were designed for a user to interact with the tool. It provides rapid evaluation of the design of a spindle system, and therefore, it would be helpful to identify a near optimal design of a spindle system based on, say, static stiffness with design changes and, consequently, FEA.

• 전기학회논문지
• /
• 제67권3호
• /
• pp.433-439
• /
• 2018

In this paper, a SDINS(strapdown inertial navigation system) rapid initial alignment technique with adaptive time delay compensation is proposed. The proposed method consists of two steps. In first step, misalignment and data latency are estimated by conducting pre-transfer alignment. Then, hybrid alignment is designed to rapidly find the misalignment changes induced by pyro-shock. To improve the performance of hybrid alignment, adaptive time delay compensation method is suggested. We verify the performance improvement of the proposed alignment scheme comparing with the conventional transfer alignment method by van test. The test result shows that the proposed alignment technique improves alignment performance.

• 천문학회보
• /
• 제38권2호
• /
• pp.86.1-86.1
• /
• 2013

Observations of a filament showing an activated barb recorded from the at the Dutch Open Telescope (DOT) on 2010 August 20 are presented. The filament developed a barb in 10 minutes, which disappeared within the next 35 minutes. Such a rapid formation and disappearance of a filament barb is unusual, and has been seldom reported. Line-of-sight velocity maps were constructed from images in seven line positions along the H-alpha line. We observe flows in the filament spine towards the barb location prior to its formation, and flows in the barb towards the spine during its disappearance. Photospheric magnetograms from Helioseismic Magnetic Imager on board the Solar Dynamics Observatory were used to determine the changes in magnetic flux in the region surrounding the barb location. The variation of magnetic flux in this duration support the view that barbs are rooted in minor magnetic polarity.