• Title/Summary/Keyword: critical means

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Supercritical CO2 Dyeing and Finishing Technology - A Review (초임계 이산화탄소 염색 및 가공 기술)

  • Lee, Gyoyoung;Chae, Juwon;Lee, Sang Oh;Kim, Sam Soo;Lee, Jaewoong
    • Textile Coloration and Finishing
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    • v.31 no.1
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    • pp.48-64
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    • 2019
  • With evolution in the production environment of the textile industry, the need for non-water-based dyeing technologies and eco-friendly process facilities in the dyeing and processing stages has increased. In recent years, supercritical fluid dyes have been developed and commercialized in Europe, centering on this demand. However, so far, such dyes have been mainly applied in the processing of PET fibers. Basic research has mainly involved investigation of dyeing by supercritical carbon dioxide or solubility of such dyes, and more in-depth research should be continuously carried out. In this review, we describe the types and characteristics of supercritical fluids that exhibit specific properties at pressures and temperatures over the critical point. In addition, the state of the art in the dyeing and processing technology using supercritical fluids and associated, processing problems, environmental regulation, and wastewater treatment issues are described in detail. We hope this review can contribute to the supercritical fluid technology being further developed as an environment friendly dyeing processing method. Furthermore, we expect that the technique can be used as a means of ensuring different, high-quality dyed products.

Performance Improvement in Single-Phase Electric Spring Control

  • Wang, Qingsong;Zuo, Wujian;Cheng, Ming;Deng, Fujin;Buja, Giuseppe
    • Journal of Power Electronics
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    • v.19 no.3
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    • pp.784-793
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    • 2019
  • Two objectives can be pursued simultaneously with the ${\delta}$ control of a single-phase electric spring (ES). These objectives are the stabilization of the voltage across the critical load (CL) of a power system, and the achievement of a specific functionality similar to the pure compensation of reactive power or the correction of the power factor. However, existing control systems implementing the ${\delta}$ control do not cope with non-ideal operating conditions, such as line voltage distortions, and exhibit a somewhat sluggish regulation of the CL voltage. In an effort to improve both the steady-state and transient performances of an ES power system, this paper proposes implementing the ${\delta}$ control by means of a control system built up on the repetitive control and assisted by state feedback with pole assignment. This paper starts by analyzing the dynamics of an ES power system in terms of its poles and zeros. After that, a reduced second-order model of the dynamics is formulated to avoid a notch filter in the pole assignment. A repetitive control for an ES power system is then designed to meet the two above mentioned objectives. Experimental tests carried out on a laboratory setup demonstrate the effectiveness of the proposed control system in significantly improving the ES power system performance, while reaching the two objectives. In particular, the tests outline the large mitigation of harmonics in the CL voltage under line voltage distortions and its fast stabilization action.

Mitophagy Improves Ethanol Tolerance in Yeast: Regulation by Mitochondrial Reactive Oxygen Species in Saccharomyces cerevisiae

  • Jing, Hongjuan;Liu, Huanhuan;Lu, Zhang;Cui, liuqing;Tan, Xiaorong
    • Journal of Microbiology and Biotechnology
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    • v.30 no.12
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    • pp.1876-1884
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    • 2020
  • Ethanol often accumulates during the process of wine fermentation, and mitophagy has critical role in ethanol output. However, the relationship between mitophagy and ethanol stress is still unclear. In this study, the expression of ATG11 and ATG32 genes exposed to ethanol stress was accessed by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). The result indicated that ethanol stress induced expression of the ATG11 and ATG32 genes. The colony sizes and the alcohol yield of atg11 and atg32 were also smaller and lower than those of wild type strain under ethanol whereas the mortality of mutants is higher. Furthermore, compared with wild type, the membrane integrity and the mitochondrial membrane potential of atg11 and atg32 exhibited greater damage following ethanol stress. In addition, a greater proportion of mutant cells were arrested at the G1/G0 cell cycle. There was more aggregation of peroxide hydrogen (H2O2) and superoxide anion (O2•-) in mutants. These changes in H2O2 and O2•- in yeasts were altered by reductants or inhibitors of scavenging enzyme by means of regulating the expression of ATG11 and ATG32 genes. Inhibitors of the mitochondrial electron transport chain (mtETC) also increased production of H2O2 and O2•- by enhancing expression of the ATG11 and ATG32 genes. Further results showed that activator or inhibitor of autophagy also activated or inhibited mitophagy by altering production of H2O2 and O2•. Therefore, ethanol stress induces mitophagy which improves yeast the tolerance to ethanol and the level of mitophagy during ethanol stress is regulated by ROS derived from mtETC.

Incident Investigator's Perspectives on Incident Investigations Conducted in Korea Industry (한국 산업계에서 사고조사 수행 시 사고조사자의 관점에 관한 연구)

  • Kwon, Jae Beom;Kwon, Young Guk
    • Journal of the Korean Society of Safety
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    • v.36 no.2
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    • pp.58-67
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    • 2021
  • Incident investigation is regarded as a means to improve safety performance. For the prevention of industrial accidents, measures such as providing safety education, enhancing management interest and participation, establishing a safety management system, and conducting inspection of the work site are necessary. In particular, accident investigation activities, which are an important element of safety management, help to prevent similar accidents, thereby minimizing damage and enhancing work safety. They are critical for understanding business-related incidents and the vulnerabilities and opportunities associated with them. Therefore, it is clear that accident investigation activities are important for accident prevention. The primary focus of many incident investigation processes is on identifying the cause of an event. While considerable research has been conducted on potential accident investigation tools there has been little research on including the views and experiences of practitioners in the accident investigation process. In this study, a questionnaire survey was conducted among safety managers in the domestic manufacturing/construction industry to understand the practice of accident investigation. The investigation pertained to companies' accident investigation systems, the competence of investigators, and the identification and recommendations of the cause of accidents. From the analysis results of accident investigations, investigators' competence, the difficulty level of investigations, and the root causes of accidents were identified from the viewpoint of the participants of the accident investigations. In particular, the development of standardized and simple accident investigation methods and their dissemination to companies were found to be necessary for activating the root cause of accidents. Based on this, it can be used as basic data for the development of root cause analysis investigation techniques that are easily applicable to organizations.

Critical Review on Theory of "Eccentric Diseases are Due to Phlegm" (괴병다속담(怪病多屬痰) 이론에 대한 비판적)

  • Bae, Sung-Jin;Choi, Jun-Yong;Kim, Kibong;Ha, Ki-Tae
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.34 no.6
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    • pp.279-284
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    • 2020
  • The theory of "eccentric diseases are generally due to phlegm (怪病多屬痰)" means that phlegm is a major cause for intractable diseases including cerebrovascular accident, depression, insanity, and shock from strange things or evil sprint. It has been a key foundation for the diagnosis and treatment of phlegm in traditional Korean medicine. However, the origin of the theory is not clear and controversial. In this study, we critically reviewed the origin and developing process of the theory in the viewpoints of philology and pathology in Korean medicine. Wang Yin-Jun (王隱 君) did not claim that eccentric diseases are generally due to phlegm in Taidingyangshengzhu-lun (泰定養生主論). The miscitation by following medical literature caused the misunderstanding in the meaning of Taidingyangshengzhu-lun, that phlegm can cause variable symptoms and signs. In the Ming dynasty, some poor medical doctors had tended to diagnose any difficult case as phlegm syndrome and to use Kuntan-huan (滾痰丸) as a standard herbal formula for treating phlegm syndrome. However, the tendency to categorize delicate cases easily to phlegm syndrome is not desirable. Besides, the tendency to use Kuntan-huan as a basic formula for the phlegm syndrome might cause diverse and severe adverse effects. Thus, we cannot accept the theory of eccentric diseases is generally due to phlegm without a doubt. In conclusion, this theory might be a valuable aphorism in terms of considering the possibility of the secondary pathologic factors including phlegm and blood stasis which should be considered first in case of intractable diseases.

An Effects of Blended Novel Engineering on Improving Creative Problem-Solving Ability (블렌디드 노벨 엔지니어링이 창의적 문제해결력 향상에 미치는 영향)

  • Hong, Ki-Cheon;Lee, Woo-Jin;Yoo, Jun-Hee
    • Journal of Industrial Convergence
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    • v.19 no.1
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    • pp.27-32
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    • 2021
  • Novel Engineering(NE) is integrated learning model to figure out problems in a book and solve them with creative engineering process. NE has been performed on offline until now. We have to research blended learning projects for COVID-19 outbreak. In this paper, we are going to explore that blended NE is effective to creative problem solving ability. The results showed that blended NE is highly effective to all of four sub-elements; self conviction & independence, diffusion thinking, critical thinking and motivational element. This means that blended novel engineering class is effective to competence-centered class proposed in 2015 revised curriculum. We hope that the research is spread and settled into our school.

Anti-tumorigenic Effects of Angelica gigase Nakai Extract on MBA-MB-231 through Regulating Lats1/2 Activation (유방암세포에서 LATS1/2 활성에 의한 당귀 추출물의 항암효과)

  • Kim, Cho-Long;Kim, Nambin;Jeong, Han-Sol;Shin, Yu-Su;Mo, Jung-Soon
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.34 no.4
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    • pp.177-183
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    • 2020
  • The Hippo-YAP signaling pathway is critical for cell proliferation, survival, and self-renewal in both Drosophila and mammals. Disorder of Hippo-YAP pathway leads to tumor development, progression and poor prognosis in various cancers. YAP/TAZ are the key downstream effectors of the Hippo pathway and they can be inhibited through LATS1/2, core kinases in the Hippo pathway, mediated phosphorylation. In this study, we investigated the effect of Angelica gigas Nakai extract (AGNE) on Hippo-YAP/TAZ pathway. First, ANGE induced YAP/TAZ phosphorylation and dissociation of the YAP/TAZ-TEAD transcription complex. By qRT-PCR, we found that ANGE inhibits the expression of YAP/TAZ-TEAD target gene, CTGF and CYR61. In addition, the transcriptional activity of YAP/TAZ was not suppressed significantly in LATS1/2 double-knockout (DKO) cells by ANGE compared to LATS1/2 wild-type (WT) cells, which means AGNE inhibits YAP/TAZ signaling through direct action on LATS1/2. Further, it was confirmed that AGNE-induced activation of LATS1/2 inhibited the migration potential of the vector-expressing cells by suppressing YAP/TAZ activity. The reduced migration potential was restored in active YAP-TEAD expressing cells. Taken together, the results of this study indicate that ANGE downregulates YAP/TAZ signaling in cells through the activation of LATS1/2.

Contents of 'true education' in the Era of New Media and the Consciousness Structure of Modern People (뉴미디어 시대 속 '참교육' 콘텐츠와 현대인의 의식구조)

  • Kim, Se-Yeon
    • The Journal of the Korea Contents Association
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    • v.22 no.4
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    • pp.468-478
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    • 2022
  • 'True education', which was the core ideology of 'the Korean Teachers & Educational Workers Union', is re-appropriated in the new media era. This word, which is actively used by young people, means 'punishment against the object of social condemnation'. One of the characteristics of 'true education contents' commonly seen on the Internet is that it shows a tendency to 'fragmentation'. True educational contents are short in length, and the contents are very local. This reflects the characteristics of a postmodern society where totality disappears and small stories are consumed. Second, the standard for dividing good and evil is extremely 'arbitrary'. Whereas the existing stories of rewarding virtue and punishing vice had universal values such as love, consideration, and peace, the content of true education distinguishes good and evil with an extremely narrow perspective. The way to justify arbitrary standard is to incite public outrage. Third, 'humour' is added. Here, humor is combined with the emotion of hatred, causing the problem of weakening people's critical consciousness.

Identification of Adaptive Traits Facilitating the Mechanized Harvesting of Adzuki Bean (Vigna angularis)

  • Xiaohan Wang;Yu-Mi Choi;Sukyeung Lee;Myoung-Jae Shin;Jung Yoon Yi;Kebede Taye Desta;Hyemyeong Yoon
    • Korean Journal of Plant Resources
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    • v.35 no.6
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    • pp.785-795
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    • 2022
  • Traditional germplasms are unsuitable for mechanized production, limiting adzuki bean production. The creation of cultivars that can be harvested by mechanized means is an urgent task for breeders. The bottom pod height (BPH), lodging resistance, and synchronous maturing of adzuki beans are critical factors for the reduction of losses due to mechanized harvesting. In this study, 14 traits of 806 adzuki bean accessions were analyzed. All growth stages and the yield, lodging score, and synchronous maturing correlated negatively with the BPH. These negative correlations reflect the increased difficulty of breeding to simultaneously satisfy the needs for no lodging, high synchronous maturing rates, BPHs > 10 cm, and high yield. We screened three germplasms with no lodging, high synchronous maturing rates, and BPHs > 10 cm that were used as mechanization-adapted breeding material for crossing with high-yield cultivars. Agronomic trait diversity in adzuki beans was also examined in this study. Principal component and cluster analyses were conducted for 806 germplasms resulting in three clusters with the yield and three growth stage traits serving as the main discriminating factors. Cluster 1 included high-yield germplasms with the number of pods per plant and the number of seeds per pod being the major discriminant factors. Cluster 2 included germplasms with long growth periods and large 100-seed weights while cluster 3 contained germplasms with high BPHs. In general, the characteristics that make mechanical harvesting feasible and those assessed in this study could be utilized to choose and enhance adzuki beans production.

FATIGUE DESIGN OF BUTT-WELDED TUBULAR JOINTS

  • Kim, D. S.;S. Nho;F. Kopp
    • Proceedings of the KWS Conference
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    • 2002.10a
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    • pp.127-132
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    • 2002
  • Recent deepwater offshore structures in Gulf of Mexico utilize butt welded tubular joints. Application of welded tubular joint includes tendons, production risers, and steel catenary risers. Fatigue life assessment of these joints becomes more critical because the structures to which they are attached are allowed to undergo cyclic and sometimes large displacements around an anchored position. Estimating the fatigue behavior of these tubular members in the design stage is generally conducted by using S-N curves specified in the codes and standards. Applying the stress concentration factor of the welded structure to S-N approach often results in very conservative assessment because the stress field acting on the tubular has a non-uniform distribution through the thickness. Fracture mechanics and fitness for service (FFS) technology have been applied in the design of the catenary risers. This technology enables the engineer to establish proper requirements on weld quality and inspection acceptance criteria to assure satisfactory structural integrity during its design life. It also provides guidance on proper design curves to be used and a methodology for accounting for the effects of non-uniform stress distribution through the wall thickness. An attempt was made to develop set of S-N curves based on fracture mechanics approach by considering non-uniform stress distribution and a threshold stress intensity factor. Series of S-N curves generated from this approach were compared to the existing S-N curves. For flat plate butt joint, the S-N curve generated from fracture mechanics matches with the IIW class 100 curve when initial crack depth was 0.5 mm (0.02"). Similar comparison with API X′ was made for tubular joint.. These initial crack depths are larger than the limits of inspection by current Non-destructive examination (NDE) means, such as Automatic Ultrasonic Inspection (AUT). Thus a safe approach can be taken by specifying acceptance criteria that are close to limits of sizing capability of the selected NDE method. The comparison illustrates conservatism built into the S-N design curve.

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