• Title/Summary/Keyword: artificial aging

Search Result 220, Processing Time 0.029 seconds

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
    • Proceedings of the SCSK Conference
    • /
    • 2003.09a
    • /
    • pp.659-659
    • /
    • 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.

  • PDF

Cognitive and Behavioral Intelligent Artificial Liferobot

  • Zhang, Yong-guang
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2001.10a
    • /
    • pp.154.1-154
    • /
    • 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.

  • PDF

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

  • Park, Jong-Seo;Lim, Yu-Jin
    • Analytical Science and Technology
    • /
    • v.25 no.3
    • /
    • pp.197-206
    • /
    • 2012
  • Ambers are composed of polymer molecules which contain aromatic moieties such as benzene, naphthalene, phenanthrene and anthracene. They emit fluorescence when irradiated with ultraviolet light, which was used for confirming an amber. The fluorescence of amber, however, tends to decrease as the surface of amber is weathered with light, heat, oxygen for a long time. In this study, the reliability of confirming amber with its fluorescence by measuring the changes of fluorescence after artificial aging. Aging factors were UV light (${\lambda}$=340 nm), oxygen with heat (100%, $90^{\circ}C$) and heat ($90^{\circ}C$) and aging time was for 5, 15, 30 and 60 days, respectively. In the excitation and emission spectra of amber, the intensity decreased and the maximal wavelength was shifted to longer wavelength with artificial aging time. Especially, there was a drastic decrease in the intensity of spectra to 1.7% of initial value after 60 days aging under oxygen with heat. Only in Colombian amber there showed an increase of fluorescence intensity for a certain aging time, which could be explained by the production of aromatic ring in the presence of light and heat. Conclusively, the fluorescence can be lessened by the natural weathering with light, heat and oxygen and it is not accurate to recognize amber just with UV irradiation method.

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

  • 손건석;윤승원;고성혁;이귀영
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.9 no.1
    • /
    • pp.1-7
    • /
    • 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.

  • PDF

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

  • Choi, Eun-Yeon;Lee, Yong-Kyu;Cho, Byoung-Uk
    • Journal of Korea Technical Association of The Pulp and Paper Industry
    • /
    • v.46 no.4
    • /
    • pp.54-61
    • /
    • 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
    • /
    • v.4 no.2
    • /
    • pp.106-114
    • /
    • 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).

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

  • Cho, H.G.;Kim, I.S.;Ahn, M.S.
    • Proceedings of the KIEE Conference
    • /
    • 1994.07b
    • /
    • pp.1360-1363
    • /
    • 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.

  • PDF

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

  • Ha, Ju-Young;Park, Hyo-Jin
    • Journal of Korean Academy of Nursing
    • /
    • v.53 no.1
    • /
    • pp.55-68
    • /
    • 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.

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

  • Yoo, D.;Kim, J.H.;Park, S.;Jang, H.K.;Kim, D.
    • Transactions of Materials Processing
    • /
    • v.30 no.2
    • /
    • pp.61-68
    • /
    • 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.

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

  • Kim, Cheol;Park, Heung-Bae;Jin, Tae-Eun;Jeong, Ill-Seok
    • Proceedings of the KSME Conference
    • /
    • 2003.11a
    • /
    • pp.1174-1179
    • /
    • 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.

  • PDF