• Title/Summary/Keyword: R410a

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Factors Affecting Perceived Stress, Depression and Sleep Disturbance on the Dysmenorrhea among Female University Students (여대생의 지각된 스트레스, 우울 및 수면장애가 월경곤란증에 미치는 영향 요인)

  • Kim, Hyang-Soo
    • Journal of the Korean Applied Science and Technology
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    • v.38 no.2
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    • pp.399-410
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    • 2021
  • This study is a descriptive research to provide the basis of program development for further dysmenorrhea relief by looking into identify the degree of perceived stress, depression, sleep disturbance, and dysmenorrhea in female university students, the relationship between these variables, and the factors influencing dysmenorrhea. We collected 160 data female university students who are attending J university. The study period lasted four weeks, going from Nov 11 to Dec 9. The correlated factors of dysmenorrhea included perceived stress(r=.420, p<.001), depression(r=.459, p<.001), sleep disturbance(r=.429, p<.001). The prevalent factors influencing dysmenorrhea are sleep disturbance, depression, perceived stress. Therefore, it will be needed to find ways and development of an intervention program to relieve perceived stress, reduce depression and enhance the sleep quality for female university students' dysmenorrhea relief.

The Effect Self-esteem, Major satisfaction and Career identity on Nurse image, in Nursing Students Perceive (간호대학생의 인지하는 자아존중감, 전공만족도 및 진로정체감이 간호사 이미지에 미치는 영향 요인)

  • Kim, Young-Hee;Kwon, Young-Chae
    • Journal of Digital Convergence
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    • v.16 no.2
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    • pp.215-224
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    • 2018
  • The Purpose of this study was to examine the relations between nurse image, self-esteem, major satisfaction and career identify of nursing students perceive. The participants of 410 subjects, data was analyzed using t-test, ANOVA, multiple linear regression with the SPSS/WIN 20.0 program. The results: The mean score of nurse image(3.82), self-esteem(2.64), major satisfaction(3.76), career identity(2.64) were abve the average. Nurse image, self-esteem, major satisfaction and career identity showed a positive correlation. The results of multiple linear regression analysis showed that the variables of self - esteem, major satisfaction, and career identity had an explanatory power(Adj R2=33.2% )on image of nurses. Study results suggested that, we propose a program for establishing a positive nurse image to improve the self - esteem, major satisfaction and career identity of nursing students.

A study on prospective dental hygiene students awareness of child abuse and attitudes towards mandatory reporting (예비 치과위생사의 아동학대 인식 및 신고 의무태도에 관한 연구)

  • Seon-Yeong Kim
    • Journal of Korean society of Dental Hygiene
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    • v.23 no.5
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    • pp.403-410
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    • 2023
  • Objectives: To confirm the awareness of child abuse and attitudes toward mandatory reporting among dental hygiene students in the Gwangju and Jeonnam regions. Methods: The level of awareness of child abuse according to general characteristics, attitudes toward reporting obligation, and awareness of the mandatory reporting system were analyzed using t-test or one-way analysis of variance (ANOVA) analysis, and correlation was analyzed using Pearson correlation coefficient. Results: Awareness of child abuse was 3.76, 3.68, 3.67, and 3.18 points for neglect, sexual abuse, physical, and emotional abuse, respectively. The attitude toward reporting obligation were 3.60 and 2.62 points for positive and negative reporting attitudes, respectively. Regarding awareness of child abuse, a significant positive correlation was observed between positive reporting attitude (r=0.326, p<0.01) and awareness of mandatory reporting system (r=0.272, p<0.01). Conclusions: To increase the reporting rate among dental hygienists, awareness should be improved starting from the undergraduate level, perceptions of prospective dental hygienists should be reflected in the development and direction of educational programs, and it is necessary to increase accessibility to educational opportunities and continuously seek institutional and policy measures.

Evaluation on Corrosion Behaviour and Adhensivity of Oxide Coated Materials (산화물 피복강재의 부식거동 및 밀착성 평가)

  • Lee Jong-Rark
    • Journal of the Korean Institute of Gas
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    • v.2 no.4
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    • pp.34-41
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    • 1998
  • To oxide film, $A1_2O_3,\;Ta_2O_5$ and $ZrO_2$, coated on stainless steel (SUS410, SUS304) and pure Fe using RF magnetron sputtering method, the corrosion resistance on oxide coatings was studied using electrochemical measurement. Also, the adherence between film and substarte was studied. The adherence index ( $\chi$ ) was determined by the measure of micro hardness test. In this paper, we know that oxide film coated on SUS304 have better corrosion resistance than that coated on SUS410. In oxide film, the difference of corrosion resistance due to crystal structure have not been showed. In evaluating defect area rate of ceramic coated materials, CPCD method can be used effectively. In the micro-hardness test, with $1{\mu}m$ thickness film, it has only one the value of $\chi$. Above $2{\mu}m$ thickness film, however, get another value of $\chi$ as the cracks in film. The oxide film adhere well on the mild materials such as pure steel than high intensity materials like stainless.

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A Study on the Thermal Analysis of the Valve in the Selective Catalytic Reduction(SCR) System (선택적 환원촉매장치(SCR)에서 밸브의 열해석에 관한 연구)

  • Choi, Jae-Wook;Kwag, Dong-Gi
    • Journal of the Korea Convergence Society
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    • v.10 no.8
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    • pp.153-158
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    • 2019
  • The overall environmental regulations of the industry have been strengthened due to environmental pollution that occurred in modern society. Therefore, R&D of selective reduction catalyst (SCR) is needed to meet these environmental regulations. This paper carried out thermal analysis to develop the pneumatic damper valve (PDV), which is a key component of SCR system. For thermal analysis, verification of material properties was performed first. Verification was performed through the thermal properties test and the thermal tensile test of the specimen, and the results were reinforced with the material properties to enhance the reliability of the thermal analysis.The heat analysis was intended to identify thermal characteristics with PDV in total of three materials (SM400B, SS275, SB410) applied under the conditions of use of PDV, and to confirm the structural stability of the PDV.

Determination of Chlorpromazine Using Plasticizers as Extraction Solvent (가소제를 이용한 클로르프로마진의 용매 추출 분광광도법)

  • Lee, Ji-Yeoun;Jung, Moon-Mo;Hur, Moon-Hye;Ahn, Moon-Kyu
    • YAKHAK HOEJI
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    • v.42 no.3
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    • pp.243-247
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    • 1998
  • A method for the determination of basic drugs based on their reaction with picric acid to form an ion-association complex extractable into several plasticizers was developed. Ba sic drugs-picric acid complexes in acid medium could be extracted quantitatively into several plasticizers except phosphates. For example, the chlorpromazine-picric acid complex showed maximum absorbance at near 410nm and was applied to extraction spectrophotometric determination of chlorpromazine. The calibration curves are linear (r>0.998) within a range from $10^{-6}to\;5{\times}10^{-4}M$ and the precision of the method was acceptable because RSD was less than 2.6% (n=7). The factors affecting the extraction system was discussed.

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A Study on the Hall losses and Magnetoresistance in Cu-Al Composite Conductor (Cu-Al 전도체에서의 홀손실과 자기저항에 관한 연구)

  • Kim, Sang-Keol;Jung, Il-Hyung;Kim, Jin-Sa;Lee, Joon-Ung
    • Proceedings of the KIEE Conference
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    • 1997.11a
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    • pp.408-410
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    • 1997
  • An anomalous magnetoresistance effect has been observed at very low temperatures for composite normal metal conductors. This anomalous behavior is due to transverse Hall currents in the composite which would result in increased $I^2R$ losses and a higher effective resistance for the composite conductor. In this paper, transverse current flow and effective resistance of Cu-Al double-strip was analyzed using finite element method for predicting the Hall losses to be resulted in anomalous magnetoresistance effect, and then be able to visualized.

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Cell Death-Associated Ribosomal RNA Cleavage in Postmortem Tissues and Its Forensic Applications

  • Kim, Ji Yeon;Kim, Yunmi;Cha, Hyo Kyeong;Lim, Hye Young;Kim, Hyungsub;Chung, Sooyoung;Hwang, Juck-Joon;Park, Seong Hwan;Son, Gi Hoon
    • Molecules and Cells
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    • v.40 no.6
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    • pp.410-417
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    • 2017
  • Estimation of postmortem interval (PMI) is a key issue in the field of forensic pathology. With the availability of quantitative analysis of RNA levels in postmortem tissues, several studies have assessed the postmortem degradation of constitutively expressed RNA species to estimate PMI. However, conventional RNA quantification as well as biochemical and physiological changes employed thus far have limitations related to standardization or normalization. The present study focuses on an interesting feature of the subdomains of certain RNA species, in which they are site-specifically cleaved during apoptotic cell death. We found that the D8 divergent domain of ribosomal RNA (rRNA) bearing cell death-related cleavage sites was rapidly removed during postmortem RNA degradation. In contrast to the fragile domain, the 5' terminal region of 28S rRNA was remarkably stable during the postmortem period. Importantly, the differences in the degradation rates between the two domains in mammalian 28S rRNA were highly proportional to increasing PMI with a significant linear correlation observed in mice as well as human autopsy tissues. In conclusion, we demonstrate that comparison of the degradation rates between domains of a single RNA species provides quantitative information on postmortem degradation states, which can be applied for the estimation of PMI.

Relation among Students' Science-related Attitudes, Science Achievement, Science Process Skills, and Teachers' Attitudes (중학생의 과학에 관련된 태도, 과학생적, 과학 탐구능력, 과학교사의 과학에 대한 태도의 상관관계)

  • An, Gae-Won;Chung, Young-Lan
    • Journal of The Korean Association For Science Education
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    • v.16 no.4
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    • pp.410-416
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    • 1996
  • The purpose of this study is to determine which variable is the best predictor of students' science-related attitudes. Three influential variables were tested : students' science achievement. students' science process skills, and teachers' attitudes toward science. This study has been made on the basis of questionnaire from 205 1st graders in 5 different middle schools in Seoul. The instruments used for measuring attitudes were TOSRA and the questionnaire developed by Sung-Jae Pak(1980). The instrument used for measuring science process skills was a standardized test developed by Youne-Woo Lee(1989). The results was analyzed by multiple-regression in the statistical packages SPSS/PC+. The major findings of this study are as follows. 1. The mean score of students' science-related attitudes was 66.8, and there was no significant difference according to gender of students and teachers(p> .05). 2. The mean score of students' science process skills was 61.1, and there was no significant difference according to gender of students and teachers(p> .05). 3. Students' science process skills was the best predictor of students' science-related attitudes among three variables(R=0.3102, p< .05). 4. The subjects were divided into 2 groups by students' science achievement. In the high score group, students' science achievement was the best predictor of students' science-related attitudes (R=0.3406, p<.05). And in the low score group, none of the variables was related to students' science-related attitudes (p> .05). 5. In students who has a male science teacher, students' science process skill was the best predictor of students' science-related attitudes (R=0.3220, p<.05). And in students who has a female science teacher, students' science achievement was the best predictor of students' science-related attitudes (R=0.3480, p<.05).

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An Experimental Study on Evaperation Heat Transfer and Pressure Drop in Plated cleat Exchangers with Different Chevron Angles (판형열교환기의 세브론각에 따른 증발 열전달특성 및 압력강하에 대한 실험적 연구)

  • Kim, Yun-Ho;Lee, Gyu-Jeong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.2
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    • pp.269-277
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    • 2002
  • Experiments on the evaporation heat transfer and pressure drop in the brazed type plate heat exchangers were performed using refrigerants R410A and R22. To investigate the geometric effect, plate heat exchangers with the same pitch and height but different 45$^{\circ}$, 35$^{\circ}$and 20$^{\circ}$chevron angles are used. Tests were conducted fur the ranges of the mass flux of refrigerant from 13 kg/m$^2$s to 34 kg/m$^2$s, the evaporation temperatures of 15$^{\circ}C$, 1$0^{\circ}C$ and 5$^{\circ}C$, vapor quality from 0.15 to 0.95 and the heat flux from 2.5 kW/m$^2$to 8.5 kW/m$^2$. The evaporation heat transfer coefficients and pressure drops were measured. Most of flow patterns are in the chum flow regime and become close to the annular flow for increasing the mass flux and the vapor quality. The heat transfer coefficient increases with increasing the evaporation temperature at a given mass flux in all plate heat exchangers. Also, the pressure drop increases with increasing the mass flux and the quality and decreasing the evaporation temperature and the chevron angle.