• Title/Summary/Keyword: barrier factor

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An Investigation into the Characteristics of the Burial Ground Materials around Mummies in Andong (안동 미이라 지역 매장지반재료의 특성규명)

  • 황지호;김성수;박형동
    • Economic and Environmental Geology
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    • v.33 no.5
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    • pp.435-442
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    • 2000
  • Although the mummies of Lee Myeong-Jung and his wife who were a member of the Moon family, were buried in similar sites in around 1560, the degree of decay of the dead bodies and antiquities between two people were quite different. This study was focused on the cause of-those differences in terms of engineering geology. Cranular soil found several metered depth around the study site has good drainage ability and such characteristic could be a factor of excellent conservation of dead body. From the physical characteristics of the lime-containing material that is considered to be a barrier from water and air, it was observed that the material around dead body of wife was more compact and denser than that of husband. Such results could be a clear evidence that the lime containing material around dead body of wife was excellent barrier for keeping away from water and air. To investigate those differences of physical characteristics and constituent materials between two lime-containing materials, minerals had to be identified from the two materials. It was revealed that lime-containing material around dead body of wife contains gypsum and more calcite, which could be the reason for better barrier preventing from water and air than those around husband.

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Pathophysiology and protective approaches of gut injury in critical illness

  • Jung, Chang Yeon;Bae, Jung Min
    • Journal of Yeungnam Medical Science
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    • v.38 no.1
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    • pp.27-33
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    • 2021
  • The gut is a complex organ that has played an important role in digestion, absorption, endocrine functions, and immunity. The gut mucosal barriers consist of the immunologic barrier and nonimmunologic barrier. During critical illnesses, the gut is susceptible to injury due to the induction of intestinal hyperpermeability. Gut hyperpermeability and barrier dysfunction may lead to systemic inflammatory response syndrome. Additionally, gut microbiota are altered during critical illnesses. The etiology of such microbiome alterations in critical illnesses is multifactorial. The interaction or systemic host defense modulation between distant organs and the gut microbiome is increasingly studied in disease research. No treatment modality exists to significantly enhance the gut epithelial integrity, permeability, or mucus layer in critically ill patients. However, multiple helpful approaches including clinical and preclinical strategies exist. Enteral nutrition is associated with an increased mucosal barrier in animal and human studies. The trophic effects of enteral nutrition might help to maintain the intestinal physiology, prevent atrophy of gut villi, reduce intestinal permeability, and protect against ischemia-reperfusion injury. The microbiome approach such as the use of probiotics, fecal microbial transplantation, and selective decontamination of the digestive tract has been suggested. However, its evidence does not have a high quality. To promote rapid hypertrophy of the small bowel, various factors have been reported, including the epidermal growth factor, membrane permeant inhibitor of myosin light chain kinase, mucus surrogate, pharmacologic vagus nerve agonist, immune-enhancing diet, and glucagon-like peptide-2 as preclinical strategies. However, the evidence remains unclear.

Study on the Switching behavior of Customers of Local Monopolistic Department Store (지방 독점 백화점 고객들의 전환행동에 관한 연구)

  • Kang, Hee-Suk
    • Journal of Global Scholars of Marketing Science
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    • v.12
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    • pp.29-57
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    • 2003
  • Customers of local monopolistic department store can switch their store more easily than ever due to the rapidly changing environment in distribution system represented by multi-store-strategy of large department stores, increase in discount store and growing non-store retailing system. Consequently, local department stores which enjoyed their business with little competition are forced to study and understand the customer switching behavior. This work is intended to understand the switching behavior characteristics of monopolistic local clepartrrent store users. For the end, previous researches are reviewed firstly, then characteristics of store-switching behavior of custorrers amid rapidly changing distribution environment are studied in view of the relations of dissatisfaction factor, switching barrier, switch intention and custorrer characteristics such as shopping orientation, variety-seeking behavior, degree of openess to competition and sociodemographics. Study shows that; 1) dissatisfaction factor is related to customer characteristics (shopping orientation and degree of openess to competition), 2) switching barrier recognition is related to customer characteristics (degree of openess to competition and sociodemographics) and dissatisfaction factor, 3) intention to switch to expected competitor is related to customer characteristics (shopping orientation, degree of openess to competition and sociodemographics) and switching barrier recognition. Accordingly, switch control strategy of the monopolistic local department store facing competitors' entry into market, must be made, specifically, in a way to understand customer characteristics and to make deliberate effort to reduce customer dissatisfaction.

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The Influence of the Service Quality on Switching Barrier and Customer Satisfaction in Skin Care Shop (피부미용실의 서비스품질이 고객만족과 전환장벽에 미치는 영향)

  • Nam, Eun-Joo;Kim, Soon-Sim
    • Journal of the Korea Fashion and Costume Design Association
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    • v.17 no.1
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    • pp.69-82
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    • 2015
  • This study is conducted to verify out whether any important differences can be made with factors of service qualities by the population statistics and trait of skin care shops. And this study is conducted to find out the relation that service qualities may influence on switching barrier and customer satisfaction. For this study, 396 questionnaires were used which had been returned from the customers of the skin care shops of Seoul, Gyeonggi and Chungchyung provinces from 15th April to fifth May, 2013. To analyze above data, frequency analysis, t-test, ANOVA, factor analysis, regression analysis are carried out by using an SPSS 18.0 statistical package. The results are as follows : The features of services of the skin care shops are analyzed into four factors which were Assurance, Materiality, Responsiveness, Agreeability. The features of switching barrier are analyzed into three factors which are Alternative attractiveness, Interpersonal relationship, Switching cost. There are important differences in the concept four service qualities of skin care shops by the features of the statistics of population according to sex, marriage, monthly income and the types of job. The four features of service qualities of the skin care shops have positive influences on the three features of switching barrier - Assurance, Responsiveness, Agreeability and the three features of customer satisfaction - Assurance, Materiality, Agreeability. Through this study, We can have the conclusion that the switching barrier made by the building up the qualities of service can prevent the customers from dropping away.

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Al2O3 High Dense Single Layer Gas Barrier by Neutral Beam Assisted Sputtering (NBAS) Process

  • Jang, Yun-Seong;Hong, Mun-Pyo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.157-157
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    • 2015
  • Recently, the growing interest in organic microelectronic devices including OLEDs has led to an increasing amount of research into their many potential applications in the area of flexible electronic devices based on plastic substrates. However, these organic devices require a gas barrier coating to prevent the permeation of water and oxygen because organic materials are highly susceptible to water and oxygen. In particular, high efficiency OLEDs require an extremely low water vapor transition rate (WVTR) of $1{\times}10^{-6}g/m^2day$. The Key factor in high quality inorganic gas barrier formation for achieving the very low WVTR required ($1{\times}10^{-6}g/m^2day$) is the suppression of defect sites and gas diffusion pathways between grain boundaries. In this study NBAS process was introduced to deposit enhanced film density single gas barrier layer with a low WVTR. Fig. 1. shows a schematic illustration of the NBAS apparatus. The NBAS process was used for the $Al_2O_3$ nano-crystal structure films deposition, as shown in Fig. 1. The NBAS system is based on the conventional RF magnetron sputtering and it has the electron cyclotron resonance (ECR) plasma source and metal reflector. $Ar^+$ ion in the ECR plasma can be accelerated into the plasma sheath between the plasma and metal reflector, which are then neutralized mainly by Auger neutralization. The neutral beam energy is controlled by the metal reflector bias. The controllable neutral beam energy can continuously change crystalline structures from an amorphous phase to nanocrystal phase of various grain sizes. The $Al_2O_3$ films can be high film density by controllable Auger neutral beam energy. we developed $Al_2O_3$ high dense barrier layer using NBAS process. We can verified that NBAS process effect can lead to formation of high density nano-crystal structure barrier layer. As a result, Fig. 2. shows that the NBAS processed $Al_2O_3$ high dense barrier layer shows excellent WVTR property as a under $2{\times}10^{-5}g/m^2day$ in the single barrier layer of 100nm thickness. Therefore, the NBAS processed $Al_2O_3$ high dense barrier layer is very suitable in the high efficiency OLED application.

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High Quality Nano Structured Single Gas Barrier Layer by Neutral Beam Assisted Sputtering (NBAS) Process

  • Jang, Yun-Sung;Lee, You-Jong;Hong, Mun-Pyo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.251-252
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    • 2012
  • Recently, the growing interest in organic microelectronic devices including OLEDs has led to an increasing amount of research into their many potential applications in the area of flexible electronic devices based on plastic substrates. However, these organic devices require a gas barrier coating to prevent the permeation of water and oxygen because organic materials are highly susceptible to water and oxygen. In particular, high efficiency OLEDs require an extremely low Water Vapor Transition Rate (WVTR) of $1{\times}10^{-6}g/m^2$/day. The Key factor in high quality inorganic gas barrier formation for achieving the very low WVTR required ($1{\times}10^{-6}g/m^2$/day) is the suppression of defect sites and gas diffusion pathways between grain boundaries. In this study, we developed an $Al_2O_3$ nano-crystal structure single gas barrier layer using a Neutral Beam Assisted Sputtering (NBAS) process. The NBAS system is based on the conventional RF magnetron sputtering and neutral beam source. The neutral beam source consists of an electron cyclotron Resonance (ECR) plasma source and metal reflector. The Ar+ ions in the ECR plasma are accelerated in the plasma sheath between the plasma and reflector, which are then neutralized by Auger neutralization. The neutral beam energies were possible to estimate indirectly through previous experiments and binary collision model. The accelerating potential is the sum of the plasma potential and reflector bias. In previous experiments, while adjusting the reflector bias, changes in the plasma density and the plasma potential were not observed. The neutral beam energy is controlled by the metal reflector bias. The NBAS process can continuously change crystalline structures from an amorphous phase to nano-crystal phase of various grain sizes within a single inorganic thin film. These NBAS process effects can lead to the formation of a nano-crystal structure barrier layer which effectively limits gas diffusion through the pathways between grain boundaries. Our results verify the nano-crystal structure of the NBAS processed $Al_2O_3$ single gas barrier layer through dielectric constant measurement, break down field measurement, and TEM analysis. Finally, the WVTR of $Al_2O_3$ nano-crystal structure single gas barrier layer was measured to be under $5{\times}10^{-6}g/m^2$/day therefore we can confirm that NBAS processed $Al_2O_3$ nano-crystal structure single gas barrier layer is suitable for OLED application.

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A Study About Electrical Properties and Fabrication Schottky Barrirer Diode Prepared on Polar/Non-Polar of 6H-SiC (극성/무극성 6H-SiC 쇼트키 베리어 다이오드 제조 및 전기적 특성 연구)

  • Kim, Kyung-Min;Park, Sung-Hyun;Lee, Won-Jae;Shin, Byoung-Chul
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.23 no.8
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    • pp.587-592
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    • 2010
  • We have fabricated schottky barrier diode (SBDs) using polar (c-plane) and non polar (a-, m-plane) n-type 6H-SiC wafers. Ni/SiC ohmic contact was accomplished on the backside of the SiC wafers by thermal evaporation and annealed for 20minutes at $950^{\circ}C$ in mixture gas ($N_2$ 90% + $H_2$ balanced). The specific contact resistance was $3.6{\times}10^{-4}{\Omega}cm^2$ after annealing at $950^{\circ}C$. The XRD results of the alloyed contact layer show that formation of $NiSi_2$ layer might be responsible for the ohmic contact. The active rectifying electrode was formed by the same thermal evaporation of Ni thin film on topside of the SiC wafers and annealed for 5 minutes at $500^{\circ}C$ in mixture gas ($N_2$ 90% + $H_2$ balanced). The electrical properties of SBDs have been characterized by means of I-V and C-V curves. The forward voltage drop is about 0.95 V, 0.8 V and 0.8 V for c-, a- and m-plane SiC SBDs respectively. The ideality factor (${\eta}$) of all SBDs have been calculated from log(I)-V plot. The values of ideality factor were 1.46, 1.46 and 1.61 for c-, a- and m-plane SiC SBDs, respectively. The schottky barrier height (SBH) of all SBDs have been calculated from C-V curve. The values of SBH were 1.37 eV, 1.09 eV and 1.02 eV for c-, a- and m-plane SiC SBDs, respectively.

An Analysis of the Relationship between Career Barrier and Career Maturity of the Adolescents (청소년의 진로장벽과 진로성숙도간의 관계분석)

  • Song, Byeong Kug;Jeon, Ju Yeon
    • Journal of Agricultural Extension & Community Development
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    • v.20 no.1
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    • pp.235-264
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    • 2013
  • The purpose of this study was to investigate the relationship between career barrier and career maturity of the adolescents who were concretely worried about their career and occupation. 672 middle school students were participated to analyze the Pearson Correlation and Multiple Regression Analyses with data collected by the questionnaire. This study revealed the following results. First, the correlational analysis showed that career barrier associated negatively with career maturity. Second, the multiple regression analysis revealed that sub-elements of career barrier which the adolescents conceived, such as the shortage of self-understanding, the shortage of self-reliance, gender-role conflict and gender discrimination, and the shortage of career and occupational information were significantly effecting their career maturity. Third, as a result of multiple regression analysis to estimate the explanability of career barrier on career maturity, career barrier among various independent factors which were correlated statistically with career maturity showed most effects on it. Also, school academic achievement was confirmed as a significant factor effecting the career maturity. Above these results imply that the perception on the career barrier of the adolescent should be reduced for increasing the career maturity. For this, career education and counselling should be positively intervened and reinforced through the school curriculum and activities.

A study on nanoparticle filtration characteristics of multilayer meltblown depth filters

  • Lee, Kang-San;Hasolli, Naim;Jeon, Seong-Min;Lee, Jae-Rang;Kim, Kwang-Deuk;Park, Young-Ok;Hwang, Jungho
    • Particle and aerosol research
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    • v.12 no.3
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    • pp.51-56
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    • 2016
  • Due to recent development in nanotechnology and increasing usage and production of nanomaterials, numerous studies related to environment, sanitation and safety handling of nanoparticle are being conducted. Since nanoparticles can be easily absorbed into human bodies through breathing process, based on their toxic substances and their large specific surface, these particles can cause serious health damage. Therefore, to reduce nanoparticle emissions, nanofiltration technology is becoming a serious issue. Filtration is a separation process during which a fluid passes through a barrier by removing the particles from the stream. Barrier filters can be made of various materials and shapes. One of the most common type of barrier filter is the fibrous filter. Fibrous filters are divided in two types: nonwoven and woven fabrics. Polypropylene is a thermoplastic material, used as a base material for melt blown nonwoven fabric. In this study, we examined filtration property of KCl nanoparticles with a mean particle diameter of 75 nm using multilayer meltblown filter samples. These experiments verify that the penetration of nanoparticle in the filter correlate with pressure drop; the meltblown layer MB1 has the greatest effect on dust collection efficiency of the filter. Among all tested samples, dust collection efficiency of 2-layer filter was best. However, when considering the overall pressure drop and dust collection efficiency, the 4-layer filter has the highest quality factor for particles smaller than 70 nm.

Effect of Standardized Boesenbergia pandurata Extract and Its Active Compound Panduratin A on Skin Hydration and Barrier Function in Human Epidermal Keratinocytes

  • Woo, Seon Wook;Rhim, Dong-Bin;Kim, Changhee;Hwang, Jae-Kwan
    • Preventive Nutrition and Food Science
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    • v.20 no.1
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    • pp.15-21
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    • 2015
  • The skin plays a key role in protecting the body from the environment and from water loss. Cornified envelope (CE) and natural moisturizing factor (NMF) are considered as the primary regulators of skin hydration and barrier function. The CE prevents loss of water from the body and is formed by cross-linking of several proteins. Among these proteins, filaggrin is an important protein because NMF is produced by the degradation of filaggrin. Proteases, including matriptase and prostasin, stimulate the generation of filaggrin from profilaggrin and caspase-14 plays a role in the degradation of filaggrin. This study elucidated the effects of an ethanol extract of Boesenbergia pandurata (Roxb.) Schltr., known as fingerroot, and its active compound panduratin A on CE formation and filaggrin processing in HaCaT, human epidermal keratinocytes. B. pandurata extract (BPE) and panduratin A significantly stimulated not only CE formation but also the expression of CE proteins, such as loricrin, involucrin, and transglutaminase, which were associated with $PPAR{\alpha}$ expression. The mRNA and protein levels of filaggrin and filaggrin-related enzymes, such as matriptase, prostasin, and caspase-14 were also up-regulated by BPE and panduratin A treatment. These results suggest that BPE and panduratin A are potential nutraceuticals which can enhance skin hydration and barrier function based on their CE formation and filaggrin processing.