• 제목/요약/키워드: artificial aging

검색결과 220건 처리시간 0.026초

DA-3711:A POTENT TISSUE-ENGINEERED ACTIVE INGREDIENTS FOR ANTI-AGING

  • Kim, B. M.;Lee, M.;Lee, J. H.;I. S. Doo;M. K. Son;S. H. Kang;Kim, W. B.;J. W. Kwon
    • 대한화장품학회:학술대회논문집
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    • 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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    • pp.659-659
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    • 2003
  • In this study, we have investigated the potent anti-aging effect of DA-3711, a cosmetic ingredient derived from artificial skin culture. The artificial skin was originally developed as a skin replacement for the treatment of chronic skin wounds. To produce DA-3711, neonatal human fibroblasts were seeded into biocompatible collagen/chitosan/glycosaminoglycan (GAG) scaffolds and cultured in Dulbecco's modified Eagle's medium (DMEM) supplemented with fetal bovine serum and nonessential amino acids. Analysis of the culture broth (DA-3711) showed that growth factors such as VEGF, TGF-$\beta$, KGF were present at significantly higher levels that in the culture broth of fibroblasts cultured in monolayer. The biological activity of DA-3711 was assessed by measuring in vitro cell proliferation and collagen synthesis of normal human fibroblasts. Fibroblasts treated with 10% DA-3711 showed a 2-fold higher proliferation and 2 to 4-fold higher collagen synthesis than untreated cells. DA-3711 also exhibited anti-oxidative effects, since cells under peroxide-induced oxidative stress showed a 30% higher viability in DA-3711-containing medium than in medium without DA-3711 addition. The results suggest that DA-3711 may have anti-aging effects by stimulating skin regeneration and protecting against oxidative stress.

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Cognitive and Behavioral Intelligent Artificial Liferobot

  • Zhang, Yong-guang
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.154.1-154
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    • 2001
  • The paper describes a new type of robot called "artificial liferobot" which is able to learn, make decisions, and behave by itself based on a brain-type computing technique called "artificial brain". The artificial liferobot has self-learning ability from the environment by the interactions between human being and it. The artificial brain makes the artificial liferobot to behave by itself with its intensions like living things as human being. We briefly introduce one attempt of our researches for developing cognitive and behavioral intelligent artificial liferobot in out laboratory. One of our purposes is the development of the artificial liferobot, which plays an Important role in taking care of elderly and infirm people in a rapidly aging society.

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인공열화에 따른 호박(amber)의 형광특성 변화 (Change of fluorescence in ambers according to artificial aging)

  • 박종서;임유진
    • 분석과학
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    • 제25권3호
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    • pp.197-206
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    • 2012
  • 호박은 benzene, naphthalene, phenanthrene, anthracene과 같은 aromatic ring을 포함하는 화합물로 구성되어 있어 자외선 조사 시 형광을 나타낸다. 하지만, 공기, 열, 빛 등에 노출되어 자연적인 열화과정을 거치면서 표면이 풍화되고 그에 따라 형광특성이 약해지는 경향이 있다. 본 연구에서는 인공적인 열화를 실시하고 형광의 변화를 관찰하여 형광현상을 이용한 호박 확인방법의 유효성을 평가하고자 하였다. 열화인자는 자외선(${\lambda}$=340 nm), 산소(100%, $90^{\circ}C$), 열($90^{\circ}C$)이고, 열화기간은 5, 15, 30, 60일로 하여 열화를 실시하였다. 자외선 조사에 따른 형광스펙트럼에서는 세 가지 인자에 대해 시간이 경과하면서 형광의 세기가 감소하고 형광의 파장은 장파장으로 이동하였다. 특히, 산소 분위기에서 열화된 호박에서는 60일이 경과한 후 형광의 세기가 초기값의 1.7%로 급격하게 감소하였다. 다만, Colombian호박의 경우 열화 후 일정시간까지 형광의 세기가 증가하고 있어 열, UV등의 인자가 오히려 aromatic ring을 생성하면서 호박화를 촉진하는 것으로 판단된다. 결론적으로, 열, 빛, 산소 등이 존재하는 자연 상태에서 호박의 형광이 약화됨을 확인할 수 있었고, 호박유물 조사에서 호박의 확인을 형광 관찰에만 의존하기는 어려운 것으로 판단된다.

산소센서의 열환에 관한 연구 (II) (A Study of Aging of Oxygen Sensor (II))

  • 손건석;윤승원;고성혁;이귀영
    • 한국자동차공학회논문집
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    • 제9권1호
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    • pp.1-7
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    • 2001
  • Oxygen sensor taken from the aftertreatment systems of 4 vehicles which had been aged in domestic field examined for aging effects on emissions using a idel engine bench. also the artificial sensor signal generated by function generator was supplied to ECU, instead of oxygen sensor to simulate aging effects of oxygen sensor. This study shows that reduction of amplitude, deformation and shift of mean value of aged sensors seriously affect on the engine out emissions and the performance of TWC.

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건열처리 인공노화가 시판지의 색상변화에 미치는 영향 (Effects of Artificial Thermal Aging on Variations in Color of Commercial Papers)

  • 최은연;이용규;조병욱
    • 펄프종이기술
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    • 제46권4호
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    • pp.54-61
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    • 2014
  • Effects of artificial thermal aging on color variations of various commercial papers (fine paper, coated paper, newsprint and filter paper) were investigated. With thermal aging at $105^{\circ}C$, most of papers showed a special trend in $a^*-b^*$ plane: the $a^*$ (red-green) values of the samples were initially reduced (heading to - $a^*$ side) and after a turning point they increased to +$a^*$ side while the $b^*$(blue-yellow) values were kept increased to +$b^*$ side (yellowing of paper). Different papers had different turning points for $a^*$ value. The filter paper consisted of a pure chemical pulp and the copy paper with OBA (optical brightening agent) showed the latest turing points. In addition, the papers without OBA showed less reduction in brightness compared with that with OBA, suggesting that OBA could adversely influence the brightness stability during thermal aging.

Chemical Transformation of Individual Asian Dust Particles Estimated by the Novel Double Detector System of Micro-PIXE

  • Ma, Chang-Jin
    • Asian Journal of Atmospheric Environment
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    • 제4권2호
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    • pp.106-114
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    • 2010
  • By the application of novel double detector system of micro-PIXE that can detect light elements (Z<14), we made an attempt to provide a thorough discussion on the aging processes of Asian dust (hereafter called "AD") particle by reaction with sea-slat. The elemental spectra and maps obtained from the microbeam radiation of micro-PIXE to individual AD particles were useful for fractionating AD particles into both internally and externally mixed particles. A spatial distribution of elements in a minute domain of single particle obtained by scanning the microbeam irradiation enabled us not only to estimate the chemical mixing state of individual AD particles but also to presume their aging processes in both ambient air and cloud. By calculating the normalized micro-PIXE net count of elements, it was possible to classify individual AD particles into three distinct groups (i.e., (1) Aging type 1: AD particle coated by the gaseous Cl evaporated by the reaction between artificial acids and sea salt; (2) Aging type 2: AD particle mixed with sea salt but no additional reaction with artificial acids; and (3) Non-aged type) A relatively high transformation rate (63.3-75.9%) was shown in large particles (greater than $5.1\;{\mu}m$ in diameter).

가속열화에 따른 옥외용 epoxy 수지 애자의 전기적특성 평가 (Evaluation on the Electrical Properties of Outdoor Epoxy Resin Insulators under Accelerated Agings)

  • 조한구;김인성;안명상
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1994년도 하계학술대회 논문집 C
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    • pp.1360-1363
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    • 1994
  • Epoxy resin insulator have good electrical properties (high electric strength, high resistivity, low dielectric loss) in addition to high mechanical strength, small dimensions and design versatility. Polymer insulator, however, are subjected to aging processes, caused by the surrounding atmosphere, which may lead to degradation of their properties. This paper describes the results of a important study on the artificial pollution test, Weather-Ometer properties and rotating wheel dip test of high voltage different aging insulators which are the most important factors for outdoor uses. Also, the objects of this paper are to (a)result of insulator under dry(wet) flashover voltage, (b)artificial pollution test of salt spay, (c)Accelerated aging test of Weather-Ometer, (d) wet and dry flashover voltage under rotating wheel dip test.

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인공지능과 간호에 관한 언론보도 기사의 키워드 네트워크 분석 및 토픽 모델링 (Keyword Network Analysis and Topic Modeling of News Articles Related to Artificial Intelligence and Nursing)

  • 하주영;박효진
    • 대한간호학회지
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    • 제53권1호
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    • pp.55-68
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    • 2023
  • Purpose: The purpose of this study was to identify the main keywords, network properties, and main topics of news articles related to artificial intelligence technology in the field of nursing. Methods: After collecting artificial intelligence-and nursing-related news articles published between January 1, 1991, and July 24, 2022, keywords were extracted via preprocessing. A total of 3,267 articles were searched, and 2,996 were used for the final analysis. Text network analysis and topic modeling were performed using NetMiner 4.4. Results: As a result of analyzing the frequency of appearance, the keywords used most frequently were education, medical robot, telecom, dementia, and the older adults living alone. Keyword network analysis revealed the following results: a density of 0.002, an average degree of 8.79, and an average distance of 2.43; the central keywords identified were 'education,' 'medical robot,' and 'fourth industry.' Five topics were derived from news articles related to artificial intelligence and nursing: 'Artificial intelligence nursing research and development in the health and medical field,' 'Education using artificial intelligence for children and youth care,' 'Nursing robot for older adults care,' 'Community care policy and artificial intelligence,' and 'Smart care technology in an aging society.' Conclusion: The use of artificial intelligence may be helpful among the local community, older adult, children, and adolescents. In particular, health management using artificial intelligence is indispensable now that we are facing a super-aging society. In the future, studies on nursing intervention and development of nursing programs using artificial intelligence should be conducted.

하이브리드 센터필러 제조 시 열처리 이력이 7075 알루미늄 합금 판재의 인장강도에 미치는 영향 (Effect of Heat Treatment History in Fabrication of Hybrid Center Pillar on Tensile Strength of 7075 Aluminum Alloy Sheet)

  • 유동훈;김지훈;박상언;장홍규;김대용
    • 소성∙가공
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    • 제30권2호
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    • pp.61-68
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    • 2021
  • As part of efforts to reduce the weight of automotive body-in-white, a hybrid center pillar with high strength 7075 aluminum alloy (AA7075) sheet and carbon fiber reinforced plastic (CFRP) has been recently studied. In the fabrication of the AA7075-CFRP hybrid center pillar, the AA7075 sheet might go through heating-forming-in-die quenching (HFQ), artificial aging, hybridizing, and then paint baking processes. In this study, we investigate the effects of the heat treatment history associated with each process on the tensile strength of the AA7075 sheet. Typical heat treatment conditions are HFQ for 20 minutes at 480℃ and then cooling down with die, artificial aging of T6 temper for 24 hours at 120℃, hybridizing for 10 minutes at 150℃, and paint baking for 20 minutes at 180℃. The tensile strength of the AA7075 sheet is continuously increased by a series of heat treatments of hybridizing and paint baking and is expected to have yield stress above 500MPa without artificial aging of T6 temper.

인공신경망을 이용한 주조 스테인리스강의 열취화 민감도 평가 (Evaluation of Thermal Embrittlement Susceptibility in Cast Austenitic Stainless Steel Using Artificial Neural Network)

  • 김철;박흥배;진태은;정일석
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 추계학술대회
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    • pp.1174-1179
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    • 2003
  • Cast austenitic stainless steel is used for several components, such as primary coolant piping, elbow, pump casing and valve bodies in light water reactors. These components are subject to thermal aging at the reactor operating temperature. Thermal aging results in spinodal decomposition of the delta-ferrite leading to increased strength and decreased toughness. This study shows that ferrite content can be predicted by use of the artificial neural network. The neural network has trained learning data of chemical components and ferrite contents using backpropagation learning process. The predicted results of the ferrite content using trained neural network are in good agreement with experimental ones.

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