• Title/Summary/Keyword: 결정수(結晶水)

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Investigation of Heavy Metal Migration from Food Contact Materials used for Food Delivery Using an Inductively Coupled Plasma-Mass Spectrometer

  • Chae-Yeon Hwang;Young-Jun Kim
    • Journal of Food Hygiene and Safety
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    • v.38 no.2
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    • pp.37-45
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    • 2023
  • The surge in food delivery systems during the coronavirus 2019 pandemic necessitated this study of heavy metal migration from food contact materials (FCMs). A total of 104 samples of FCMs, comprising 51 polypropylene (PP), 21 polyethylene (PE), and 32 polystyrene (PS) samples of six different types of FCMs (containers, covers, table utensils, cups, pouches, and wrappers) used for food delivery distributed in Korea, were collected and investigated for migration of three heavy metals (Pb, Cd, and As) using inductively coupled plasma-mass spectrometry (ICP-MS) to determine whether they complied with Korea's Standards and Specifications for Utensils, Containers, and Packages. Acetic acid (4%, v/v) was used as the food simulant, and tests were performed at 100℃ (in harsh conditions) for 30 min. Linearity of Pb, Cd, and As showed acceptable results with a coefficient of determination (R2) value of 0.9999. Limit of detection (LOD) and limit of quantification (LOQ) of Pb, Cd, and As were 0.001, 0.001, and 0.001 ㎍/L and 0.002, 0.003, and 0.003 ㎍/L, respectively. Accuracy and precision results complied with the criteria presented in the European Commission Joint Research Centre guidelines. The average concentration of Pb, Cd, and As migration detected in a total of 104 samples was 0.009-0.260 ㎍/L, which was very low compared with the migration specification set in the Standards and Specifications for Utensils, Containers, and Packages. The maximum level of Pb corresponded to 0.23% of the migration limit. There were no samples exceeding the limit. Thus, this study confirmed that the heavy metal contents of FCMs used for delivery food distributed in Korea were safely managed. The data from this study represent an invaluable source for science-based safety management of hazardous heavy metals migrating from FCMs used in the food delivery industry.

Estimation of Structural Deterioration of Sewer using Markov Chain Model (마르코프 연쇄 모델을 이용한 하수관로의 구조적 노후도 추정)

  • Kang, Byong Jun;Yoo, Soon Yu;Zhang, Chuanli;Park, Kyoo Hong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.43 no.4
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    • pp.421-431
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    • 2023
  • Sewer deterioration models can offer important information on prediction of future condition of the asset to decision makers in their implementing sewer pipe networks management program. In this study, Markov chain model was used to estimate sewer deterioration trend based on the historical structural condition assessment data obtained by CCTV inspection. The data used in this study were limited to Hume pipe with diameter of 450 mm and 600 mm in three sub-catchment areas in city A, which were collected by CCTV inspection projects performed in 1998-1999 and 2010-2011. As a result, it was found that sewers in sub-catchment area EM have deteriorated faster than those in other two sub-catchments. Various main defects were to generate in 29% of 450 mm sewers and 38% of 600 mm in 35 years after the installation, while serious failure in 62% of 450 mm sewers and 74% of 600 mm in 100 years after the installation in sub-catchment area EM. In sub-catchment area SN, main defects were to generate in 26% of 450 mm sewers and 35% of 600 mm in 35 years after the installation, while in sub-catchment area HK main defects were to generate in 27% of 450 mm sewers and 37% of 600 mm in 35 years after the installation. Larger sewer pipes of 600 mm were found to deteriorate faster than smaller sewer pipes of 450 mm by about 12 years. Assuming that the percentage of main defects generation could be set as 40% to estimate the life expectancy of the sewers, it was estimated as 60 years in sub-catchment area SN, 42 years in sub-catchment area EM, 59 years in sub-catchment area HK for 450 mm sewer pipes, respectively. For 600 mm sewer pipes, on the other hand, it was estimated as 43 years, 34 years, 39 years in sub-catchment areas SN, EM, and HK, respectively.

Analysis of Factors Affecting the Length of Stay in Children(Aged 0 to 12) with Injuries: Centering Around the Data from the Korea National Hospital Discharge In-Depth Injury Surveys (어린이(0-12세) 손상환자의 재원일수에 미치는 요인분석: 퇴원손상심층자료를 중심으로)

  • Lee Chae Kyung
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.3
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    • pp.137-143
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    • 2023
  • This study was conducted to analyze factors affecting the length of stay in children with injuries by determining relationships between length of stay and characteristics of children(aged 0 to 12) with injuries. 7,804 patients aged 0 to 12 who participated in the Korea Nation Hospital Discharge In-Depth Injury Surveys, got a diagnosis of sequelae of injuries and of other consequences of external causes(S00-T98), and were discharged between 1 January 2016 and 31 December 2020 were investigated. A frequency analysis, independent samples t-test, and ANOVA were performed. Also, to identify factors affecting the length of stay, a regression analysis was performed. The average length of stay for the patients investigated in this study was 5.5 days. The length of stay for school-age children(aged 7 to 12) and children who had either public or private coverage was higher than that for preschoolers(aged 0 to 6) and children who didn't have public or private coverage, respectively. The length of stay for children admitted to a hospital in a rural area(Jeolla-do or Gyeongsang-do) was higher than that for children admitted to a hospital in a metropolitan area and the length of stay for children admitted to a hospital that had 100-299 hospital beds was relatively long. However, children who first visited a hospital for outpatient care stayed relatively short in hospital and children who had been burned or injured in traffic crashes stayed relatively long in hospital. Children who got a secondary diagnosis and had a principal procedure or who died after being discharged were in hospital for a long time. The findings of this study shall be useful, as they identified characteristics related to the length of stay for Korean children with injuries and factors that determine the length of stay for those children by analyzing the national dataset, or more specifically, the data from the Korea National Hospital Discharge In-Depth Injury Surveys. The risk of child injuries can be easily reduced by taking actions to prevent them and providing safety education programs. The present study has provided essential baseline data for the provision of aggressive care for child injuries and the establishment of a range of policies for child injury prevention.

Discuss on the Historical Development and Change of Chinese Piquancy Addiction (중국사람들의 매운 맛 기호의 역사적 추이에 대한 논술)

  • Zhao, Rong-Guang
    • Journal of the Korean Society of Food Culture
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    • v.23 no.2
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    • pp.293-300
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    • 2008
  • It determines Chinese addiction to piquancy that the Chinese traditional food production laid excessively particular stress on agriculture coming into being long before in the history and the state of Chinese food living was that the people were very difficult to live. The history of Chinese addiction to piquancy could be traced back to prehistory. And in Chinese “hot” is separated from “peppery” and it refers in particular to the piquancy more than general peppery. The character of “Hot” appeared after Han Dynasty in Chinese. Capsicum was brought to China from the sea in the middle of Ming Dynasty. Then it surpassed the formers soon and became the most popular and addictive piquancy food in China. Capsicum has many names in China, such as “$F{\bar{a}}nji{\bar{a}}o$”, “$H{\bar{a}}iji{\bar{a}}o$”, “$L{\grave{a}}ji{\check{a}}o$”, “$L{\grave{a}}h{\breve{u}}$”, “$L{\grave{a}}zi$”, etc., and they indicate the geographical and humanistic character of the distribution. (eight books on preserving one’s health) is the earliest history record about capsicum in existent Chinese history record that was finished in 1591. In this article the author puts new opinion forward on the record in this book. It is because the hottest piquancy of capsicum, capsicum’s better adaptability and low cost to plant combine with Chinese piquancy addiction at large that capsicum can replace the status of pepper and other traditional peppery flavorings soon and cause worldwide attention to the Chinese piquancy addiction finally. The human common characters of unchangeable inertia, depending to fully grow addiction and aggrieved delight are the most important reasons to cause piquancy addiction that has formed a custom through long-repeated practice and this custom do not change with condition change. The unbalanced spread process of capsicum in China shows that the region is poorer and the addictive degree is deeper.

Studies on the Maturation of the Follicular Oocytes by Xenoplastical Transplantation in the Anterior Chamber of the Eye (異種動物의 眼前房에 이식된 濾胞卵子의 成熟에 관한 연구)

  • Cho, Wan Kyoo
    • The Korean Journal of Zoology
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    • v.13 no.3
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    • pp.68-74
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    • 1970
  • In the previous studies, the present author found that high proportion of the follicular oocytes from mouse and rabbit ovaries are able to resume their maturation division in the anterior chamber of the eye in which they have been incubated by auto- or homoplastic transplantation. Especially in the case of the homoplastic transplantation, it was known that no trouble has been detected in the process of resumption of the oval maturation in particular connection with the antigen-antibody reaction between donor and recipient. These findings provide a possibility that the follicular oocytes from various animals would be matured in the eye even after the xenoplastic transplantation. Under such an assumption, the present studies were performed to examine the behavior of the follicular oocytes in the eye chamber of the animals of different species. For the donor of the follicular oocytes, domestic rabbits, albino rats of Sprague-Dowley strain, and albino mice of A-strain bred in our laboratory were used. The oocytes obtained from the ovarian follicules were introduced to the anterior chamber of the eye of different species of animals, with an exception of rabbit in which only the female animals were used as a recipient. The procedures of collection of ova, introduction to the eye, harvest from the eye ball, fixation, and staining were the same as mentioned in the previous reports (Cho, 1967b; Cho and Kim, 1968). The conclusions obtained are summarized as below. 1. The rabbit follicular oocytes are able to mature in the eye chambers of both male mouse and rat, although the proportion of the maturation is lower than when they are incubated autoplastically in the eye. When the ova were incubated in the male mouse eye for 24 hours, 21 per cent of them showed chromosomes at metaphase I and II, whereas the rate was 32 per cent when they were incubated in the eye of the male rat. These are apparently low comparing to the rate of 52 per cent of autoplastic transplantation. 2. When rat follicular oocytes were transferred into the mouse eye chamber and recovered after 24 hours, 43 per cent of them produced the mataphase I and II chromosomes. This proportion was higher than the result of the homoplastic transplantation which yielded 23 per cent of the ova on maturation. 3. The most striking result was found in the experiment with mouse follicular oocytes. Seventy-six per cent of the oocytes resumed their maturation division within 24 hours after they were transferred into the male rat eye chamber, and this figure was significantly high compared to the result o 55 per cent obtained by the homoplastic transplantation. In the rat eye, the induction of the degenerative ova also was low (19%). On the other hand, the proportion of the oval maturation decreased to 45 per cent, while that of degeneration increased 33 per cent when they were incubated in the eye of the female rabbit. 4. It was apparent from the present experiments that the follicular oocytes can reveal their activation to maturation in the eye chamber which contains aqueous humor which is known to be composed of low protein content and of very little gamma-globulin which acts as an antibody(Oser, 1965), and that it shows higher osmolarity than blood serum(Levene, 1958). Taking these properities into consideration the humor may provide unfavourable environment to the cells and tissues incubated in. However, it could be noteworthy finding that only the follicular oocytes in the eye of the different species can grow in healthy condition although the maturation rates are varied with the animal species. The fact that the rabbit follicular oocytes show the lower proportion in maturation may be due to the greater amount of the yolk granules in the egg cytoplasm than those in the mouse and rat oocytes. That the mouse oocytes incubated in the eye of the rat mouse and rat oocytes. That the mouse oocytes incubated in the eye of the rat resumed their maturation process in greater proportion would e explained by the fact that the rat eye chamber particularly provides the better environment to the mouse oocytes than the eye chamber of mouse does.

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Factors influencing happiness among Korean adolescents: With specific focus on the influence of psychological, relational and financial resources and academic achievement (한국 청소년의 행복: 심리적, 관계적, 경제적 자원과 학업성취의 영향)

  • Youngshin Park;Uichol Kim
    • Korean Journal of Culture and Social Issue
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    • v.15 no.3
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    • pp.399-429
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    • 2009
  • The purpose of this research examines the factors that influence happiness among Korean adolescents by focusing on psychological resource (as measured by self-efficacy), relational resource (as measured by social support) and financial resource (as measured by family's monthly income). In addition, the influence of academic achievement on happiness is examined. To examine the influence of socio-economic status and family's monthly income, adolescents living in three different districts in Seoul (from working to middle to upper class districts) were randomly selected and interviewed in their home. A total of 190 elementary school, middle school, high school and university students (male=83, female=107) completed the resiliency of efficacy scale developed by Bandura (1995) and emotional support and happiness scale developed by the present researchers, in addition to background information. The results of the path analysis are as follows. First, the most important predictor of happiness among Korean adolescents is relational resources. In other words, emotional support received from significant others was most predictive of happiness; more than 60 times the effect of family's monthly income, three times the effect of academic achievement, and two times the effect of resiliency of efficacy. The second most important factor that predicted the happiness of Korean adolescents was psychological resource (i.e., resiliency of efficacy), which had 30 times the effect of family's monthly income. In addition resiliency of efficacy played a mediating role between emotional support on one hand and happiness on the other. Third, those respondents who had higher academic achievement reported higher levels of happiness, which had 20 times the effect of family's monthly income. Fourth, family monthly income did not predict happiness among Korean adolescents. Fifth, socio-economic status and school level did not have direct influence on happiness but had mediating influence through their influence on emotional support. In other words, those respondents with higher socio-economic status and elementary school students were more likely to receive social support from significant others, which in turn increased their happiness. These results indicate that the most important predictor of happiness among Korean adolescents is emotional support, followed by resiliency of effic acy and academic achievement, indicating that those adolescents from wealthy families are not necessarily happier.

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A study of analytical method for Benzo[a]pyrene in edible oils (식용유지 중 벤조피렌 분석법 비교 연구)

  • Min-Jeong Kim;jun-Young Park;Min-Ju Kim;Eun-Young Jo;Mi-Young Park;Nan-Sook Han;Sook-Nam Hwang
    • Analytical Science and Technology
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    • v.36 no.6
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    • pp.291-299
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    • 2023
  • The benzo[a]pyrene in edible oils is extracted using methods such as Liquid-liquid, soxhlet and ultrasound-assisted extraction. However these extraction methods have significant drawbacks, such as long extraction time and large amount of solvent usage. To overcome these drawbacks, this study attempted to improve the current complex benzo[a]pyrene analysis method by applying the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method that can be analyzed in a simple and short time. The QuEChERS method applied in this study includes extraction of benzo[a]pyrene into n-hexane saturated acetonitrile and n-hexane. After extraction and distribution using magnesium sulfate and sodium chloride, benzo[a]pyrene is analyzed by liquid chromatography with fluorescence detector (LC/FLR). As a result of method validation of the new method, the limit of detection (LOD) and quantification (LOQ) were 0.02 ㎍/kg and 0.05 ㎍/kg, respectively. The calibration curves were constructed using five levels (0.1~10 ㎍/kg) and coefficient (R2) was above 0.99. Mean recovery ratio was ranged from 74.5 to 79.3 % with a relative standard deviation (RSD) between 0.52 to 1.58 %. The accuracy and precision were 72.6~79.4 % and 0.14~7.20 %, respectively. All results satisfied the criteria ranges requested in the Food Safety Evaluation Department guidelines (2016) and AOAC official method of analysis (2023). Therefore, the analysis method presented in this study was a relatively simple pretreatment method compared to the existing analysis method, which reduced the analysis time and solvent use to 92 % and 96 %, respectively.

The Effect of Service Experience on Behavioral Loyalty in Luxury Restaurant Service Setting : The Causal Role of Cognitive Satisfaction and Emotional Attachment (고급레스토랑의 서비스경험이 행동충성도에 미치는 영향 : 인지만족과 정서애착의 인과적 역할)

  • Choi, Chuljae
    • Journal of Venture Innovation
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    • v.4 no.3
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    • pp.1-15
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    • 2021
  • Due to long-term social distancing due to the spread of COVID-19, business trends of restaurant companies are being implemented in accordance with the changed environment such as packaging and subscription. However, even in this environment, upscale restaurants are generating high profits by trying to differentiate themselves from existing restaurants by providing high-quality services with the best facilities. Therefore, this study describes how customers' experience of upscale restaurant service influences behavioral loyalty. That is, the purpose of this study is to determine the effect of service experience on cognitive satisfaction and emotional attachment, and to examine the causal role of cognitive satisfaction and emotional attachment by confirming the relationship between these constructs and relationship commitment and behavioral loyalty. To verify this, data were collected through face-to-face interviews with 300 consumers who recently used a upscale restaurant. Of the collected data, 275 copies(91.6%) were used for the final analysis, and inaccurate or erroneous data among 25 response sheets were excluded. In this study, the validity and reliability of the data were checked and the research hypothesis was verified by using SPSS 21.0 and AMOS 20 statistical package. Frequency analysis was performed to confirm the demographic characteristics of the respondent. Structural equation model analysis(SEM) was used to confirm the fit of the research model and to verify the research hypothesis. As a result of the research hypothesis analysis, it was found that service experience had a positive effect on cognitive satisfaction, and cognitive satisfaction had a positive effect on emotional attachment, relationship commitment, and behavioral loyalty. Also, it was found that emotional attachment had a positive effect on relationship commitment and behavioral loyalty, and relationship commitment had a positive effect on behavioral loyalty. However, service experience did not affect emotional attachment. With this study, marketers and managers of upscale restaurants such as hotel restaurants need to accurately select their target audience, understand their service needs, and then present the appropriate service to them. In addition, they should not only induce cognitive satisfaction by providing excellent service to their customers, but also identify moments of truth and present appropriate services so that satisfied customers can strengthen their emotional attachment. In addition, it is necessary to strengthen the relationship with their firms by forming friendly relationships with customers who have high emotional attachment, and also to induce relationship commitment so that such customers have a strong sense of belonging and attachment to their firms.

The Effect of Consumption Value and Consumers' Need for Cognition on Satisfaction through the Mediating Role of Trust in Online Shopping Websites (소비가치와 소비자의 인지욕구가 온라인 쇼핑 웹사이트에 대한 신뢰성을 매개로 만족도에 미치는 영향)

  • Lee, Yun-sun
    • Journal of Venture Innovation
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    • v.6 no.4
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    • pp.99-111
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    • 2023
  • This study aims to confirm that consumers' satisfaction with online shopping websites has changed to a phenomenon different from the past. In other words, in a situation where the use of e-commerce is expanding worldwide after the pandemic and various types of commerce such as mobile commerce and social commerce are formed, the consumer's information processing and decision-making process are meaningful in examining the behavior that has been changed based on the perceived motivation level of consumers by the new environment according to the consumption value and personal characteristics perceived by the consumer. In other words, the purpose of this study was to investigate the effect of consumption value and need for cognition on the satisfaction toward online websites as a mediating role in the trust of the website. As a result of testing Hypothesis 1, not only the hedonic value of the consumer for the website but also the utilitarian value had a positive influence on the satisfaction toward the website, and in particular, the utilitarian value showed a relatively greater influence than the hedonic value. However, the negative relationship between the need for cognition and satisfaction was found to be at a significant level under one-sided verification. In Hypothesis 2, only the utilitarian value among the consumption values of 2-1 showed a positive effect on satisfaction through a mediating role of trust. It was confirmed that the utilitarian value among the consumption values was an important factor in the satisfaction toward the website. The significance of this study is that, unlike previous research results, not only consumption value based on senses and emotions but also utilitarian value has a greater influence. Therefore, utilitarian value and need for cognition have a stronger influence on satisfaction if they play a mediating role based on the trust of the website used by consumers. These findings reflect the current market trend of online consumption, and they are helpful in the management and strategy of online websites based on consumer behavior understanding and major factors.

The study of heavy rain warning in Gangwon State using threshold rainfall (침수유발 강우량을 이용한 강원특별자치도 호우특보 기준에 관한 연구)

  • Lee, Hyeonjia;Kang, Donghob;Lee, Iksangc;Kim, Byungsikd
    • Journal of Korea Water Resources Association
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    • v.56 no.11
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    • pp.751-764
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    • 2023
  • Gangwon State is centered on the Taebaek Mountains with very different climate characteristics depending on the region, and localized heavy rainfall is a frequent occurrence. Heavy rain disasters have a short duration and high spatial and temporal variability, causing many casualties and property damage. In the last 10 years (2012~2021), the number of heavy rain disasters in Gangwon State was 28, with an average cost of 45.6 billion won. To reduce heavy rain disasters, it is necessary to establish a disaster management plan at the local level. In particular, the current criteria for heavy rain warnings are uniform and do not consider local characteristics. Therefore, this study aims to propose a heavy rainfall warning criteria that considers the threshold rainfall for the advisory areas located in Gangwon State. As a result of analyzing the representative value of threshold rainfall by advisory area, the Mean value was similar to the criteria for issuing a heavy rain warning, and it was selected as the criteria for a heavy rain warning in this study. The rainfall events of Typhoon Mitag in 2019, Typhoons Maysak and Haishen in 2020, and Typhoon Khanun in 2023 were applied as rainfall events to review the criteria for heavy rainfall warnings, as a result of Hit Rate accuracy verification, this study reflects the actual warning well with 72% in Gangneung Plain and 98% in Wonju. The criteria for heavy rain warnings in this study are the same as the crisis warning stages (Attention, Caution, Alert, and Danger), which are considered to be possible for preemptive rain disaster response. The results of this study are expected to complement the uniform decision-making system for responding to heavy rain disasters in the future and can be used as a basis for heavy rain warnings that consider disaster risk by region.