• 한국세라믹학회지
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• 제55권1호
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• pp.36-43
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• 2018

The physical and chemical analyses of mineral waste such as moisture content, water absorption, freezing-thawing resisting sexual, chemical composition and crystal structure were investigated. In the technological process of crushing, screening, molding, drying, preheating, sintering and cooling, many parameters were changed to eliminate the influence of freeze thaw stability and the ball billets were processed into slate ceramsites eventually. Adopting orthogonal experiment and range analysis, the optimal technology parameters were confirmed as preheating temperature of $300^{\circ}C$ for 25 minutes and sintering temperature of $1230^{\circ}C$ for 20 minutes. Slate wastes in Shangri-la could foam and expand without any additive. The ultra-light ceramsite could be directly used as building aggregate, since the analysis results of its leaching toxicity were eligible. Besides, effects of sintering temperature on physical property and crystal phase were also explored in this study.

• Elastomers and Composites
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• 제41권2호
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• pp.125-130
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• 2006

폴리우레탄(PU)과 폴리에틸렌비닐아세터이트(EVA) 미드솔이 스포츠화의 굽힘 강성에 미치는 영향을 이해하기 위하여 두께와 경도가 다른 중창으로 스포츠화를 제조하여 중창이 스포츠화의 굽힘특성에 미치는 영향을 고찰하였다. 스포츠화의 굽힘 모멘트는 굽힘 각도 $19^{\circ}$에서 나타나기 시작했으며, 이 초기 굽힘각도는 중창의 경도나 두께에 무관한 것으로 나타났다. 중창의 경도 및 두께가 증가함에 따라 스포츠화의 굽힘 모멘트의 값은 현저하게 증가하는 경향을 나타내었다. 발포체 시트나 미드솔 자체만으로 비교하였을 때보다 스포츠화의 굽힘 강성이 미드솔의 두께나 경도 등 신발의 설계에 따라 더욱 크게 영향을 받는 것으로 나타났다.

• 한국식생활문화학회지
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• 제9권4호
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• pp.335-340
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• 1994

The objective of this study was to determine effects of soybean oil(SO), cottonseed oil(CO) and ricebran oil(RO) on stability and flavor of yackwa. This study consisted of yackwa fried in 3 differnet oils, then stored for 0, 3, 6 weeks in normal wrap at room temp. or vaccum package at $4^{\circ}C$. The moisture, oil contents, Hunter color values(L, 'a' and 'b'), % free fatty acid(FFA), thiobarbituric acid(TBA) value and sensory scores for color, flavor and acceptability were analyzed. The foam height of the oil after frying was also determined. Yackwa fried in RO was more red('a'=11.43) than yackwa fried in SO(10.64) or CO(10.51). TBA value of yackwa showed no difference among frying oils. Yackwa fried in SO showed better acceptability than those fried in CO. Yackwa fried in RO showed similar acceptability to yackwa fried in SO. The % FFA and TBA value of yackwa averaged across oil and package showed increasing tendency during 6 weeks storage.

• 한국재료학회지
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• 제12권9호
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• pp.729-734
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• 2002

Porous Al metal was produced by batch type casting process. In this foaming process, the viscosity and surface tension of molten Al as two most important factors have been investigated in the temperature range of 680-95$0^{\circ}C$ by the ring method and rotational method respectively. The experimental results showed that both the surface tension and viscosity of the melt decreased linearly with increasing temperature. Addition of Ca decreased surface tension, but increased viscosity significantly.

• International Journal of Automotive Technology
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• 제6권2호
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• pp.95-105
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• 2005

Diesel engines have low specific fuel consumption, but high particulate emissions, mainly soot. Diesel soot is suspected to have significant effects on the health of living beings and might also affect global warming. Hence stringent measures have been put in place in a number of countries and will be even stronger in the near future. Diesel engines require either advanced integrated exhaust after treatment systems or modified engine models to meet the statutory norms. Experimental analysis to study the emission characteristics is a time consuming affair. In such situations, the real picture of engine control can be obtained by the modeling of trend prediction. In this article, an effort has been made to predict emissions smoke and NO$_{x}$ using cylinder combustion derived parameters and diesel particulate filter data, with artificial neural network techniques in MATLAB environment. The model is based on three layer neural network with a back propagation learning algorithm. The training and test data of emissions were collected from experimental set up in the laboratory for different loads. The network is trained to predict the values of emission with training values. Regression analysis between test and predicted value from neural network shows least error. This approach helps in the reduction of the experimentation required to determine the smoke and NO$_{x}$ for the catalyst coated filters.

• Archives of Plastic Surgery
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• 제48권4호
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• pp.448-456
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• 2021

Background Locoregional stem cell delivery is very important for increasing the efficiency of cell therapy. Amnisite BA (Amnisite) is a freeze-dried amniotic membrane harvested from bovine placenta. The objective of this study was to investigate the retention of cells of the stromal vascular fraction (SVF) on Amnisite and to determine the effects of cell-loaded Amnisite in a porcine radiation-induced chronic wound model. Methods Initially, experiments were conducted to find the most suitable hydration and incubation conditions for the attachment of SVF cells extracted from pig fat to Amnisite. Before seeding, SVFs were labeled with PKH67. The SVF cell-loaded Amnisite (group S), Amnisite only (group A), and polyurethane foam (group C) were applied to treat radiation-induced chronic wounds in a porcine model. Biopsy was performed at 10, 14, and 21 days post-operation for histological analysis. Results Retaining the SVF on Amnisite required 30 minutes for hydration and 1 hour for incubation. A PKH67 fluorescence study showed that Amnisite successfully delivered the SVF to the wounds. In histological analysis, group S showed increased re-epithelialization and revascularization with decreased inflammation at 10 days post-operation. Conclusions SVFs had acceptable adherence on hydrated Amnisite, with successful cell delivery to a radiation-induced chronic wound model.

• Safety and Health at Work
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• 제12권2호
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• pp.184-191
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• 2021

Background: Hearing protection devices (HPDs) are often used in the workplace to prevent hearing damage caused by noise. However, a factor that can lead to hearing loss in the workplace is improper HPD fitting, and the previous literature has shown that instructing workers on how to properly insert their HPDs can make a significant difference in the degree of attenuation. Methods: Two studies were completed on a total of 33 Hydro One workers. A FitCheck Solo field attenuation estimation system was used to measure the personal attenuation rating (PAR) before and after providing one-on-one fitting instructions. In addition, external ear canal diameters were measured, and a questionnaire with items related to frequency of use, confidence, and discomfort was administered. Results: Training led to an improvement in HPD attenuation, particularly for participants with poorer PARs before training. The questionnaire results indicated that much HPD discomfort is caused by heat, humidity, and communication difficulties. External ear canal asymmetry did not appear to significantly influence the measured PAR. Conclusion: In accordance with the previous literature, our studies suggest that one-on-one instruction is an effective training method for HPD use. Addressing discomfort issues from heat, humidity, and communication issues could help to improve the use of HPDs in the workplace. Further research into the effects of canal asymmetry on the PAR is needed.

• Journal of Microbiology and Biotechnology
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• 제32권11호
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• pp.1406-1415
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• 2022

The formation of macrophage foam cells stimulated by oxidized low-density lipoprotein (ox-LDL) is deemed an important cause of atherosclerosis. Transcription factor Yin Yang 1 (YY1), which is a universally expressed multifunctional protein, is closely related to cell metabolism disorders such as lipid metabolism, sugar metabolism, and bile acid metabolism. However, whether YY1 is involved in macrophage inflammation and lipid accumulation still remains unknown. After mouse macrophage cell line RAW264.7 cells were induced by ox-LDL, YY1 and proprotein convertase subtilisin/kexin type 9 (PCSK9) expressions were found to be increased while low-density lipoprotein receptor (LDLR) expression was lowly expressed. Subsequently, through reverse transcription-quantitative polymerase chain reaction (RT-qPCR), Western blot analysis, Oil Red O staining and cholesterol quantification, it turned out that silencing of YY1 attenuated the inflammatory response and lipid accumulation in RAW264.7 cells caused by ox-LDL. Moreover, results from the JASPAR database, chromatin immunoprecipitation (ChIP) assay, luciferase reporter assay and Western blot analysis suggested that YY1 activated PCSK9 by binding to PCSK9 promoter and modulated the expression of LDLR in the downstream of PCSK9. In addition, the results of functional experiments demonstrated that the inhibitory effects of YY1 interference on ox-LDL-mediated macrophage inflammation and lipid accumulation were reversed by PCSK9 overexpression. To sum up, YY1 depletion inhibited its activation of PCSK9, thereby reducing cellular inflammatory response, cholesterol homeostasis imbalance, and lipid accumulation caused by ox-LDL.

• 대한본초학회지
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• 제38권3호
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• pp.11-18
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• 2023

Objectives : This study aimed to investigate the effect of face washing on pore changes in a controlled environment without external condition changes. The research compared the results of water washing, foam cleanser (F/C) washing, and herb cp (cold process) soap washing on pore reduction. Methods : The experiment was conducted using the same water and towel, in the same place, before and 10 minutes after washing. The skin test was performed before and after washing, and three cases of herb cp soap were tested: Ginseng, Liriope platyphylla (LP), and Castanea crenata inner shell (CCIS). A control group was established using water and F/C washing. Results : Water washing and F/C washing showed a similar degree of pore reduction. Men and individuals with complex skin types showed significantly larger pores. LP cp soap showed the greatest significance in pore reduction. Conclusion : This study found that pore shrinking effects were observed regardless of the use of facial cleansers. LP cp soap was found to be the most effective in reducing pore size. It is important to emphasize the importance of face washing for individuals with large pores and combination skin types, especially men.