• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제21권2호
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• pp.89-107
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• 2017

In this paper, we have proposed a modified Marker-And-Cell (MAC) method to investigate the problem of an unsteady 2-D incompressible flow with heat and mass transfer at low, moderate, and high Reynolds numbers with no-slip and slip boundary conditions. We have used this method to solve the governing equations along with the boundary conditions and thereby to compute the flow variables, viz. u-velocity, v-velocity, P, T, and C. We have used the staggered grid approach of this method to discretize the governing equations of the problem. A modified MAC algorithm was proposed and used to compute the numerical solutions of the flow variables for Reynolds numbers Re = 10, 500, and 50000 in consonance with low, moderate, and high Reynolds numbers. We have also used appropriate Prandtl (Pr) and Schmidt (Sc) numbers in consistence with relevancy of the physical problem considered. We have executed this modified MAC algorithm with the aid of a computer program developed and run in C compiler. We have also computed numerical solutions of local Nusselt (Nu) and Sherwood (Sh) numbers along the horizontal line through the geometric center at low, moderate, and high Reynolds numbers for fixed Pr = 6.62 and Sc = 340 for two grid systems at time t = 0.0001s. Our numerical solutions for u and v velocities along the vertical and horizontal line through the geometric center of the square cavity for Re = 100 has been compared with benchmark solutions available in the literature and it has been found that they are in good agreement. The present numerical results indicate that, as we move along the horizontal line through the geometric center of the domain, we observed that, the heat and mass transfer decreases up to the geometric center. It, then, increases symmetrically.

• Corrosion Science and Technology
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• 제7권1호
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• pp.27-34
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• 2008

In industrial and fluid handling systems, frequently the protective film forming materials suffer from severe corrosion due to microbial effects. As an example, various micro-organisms, including bacteria, exist in seawater normally fed to power and desalination plants. Unless seawater intakes are properly disinfected to control these microbial organisms, biological fouling and microbial induced corrosion (MIC) will be developed. This problem could destroy metallic alloys used for plant construction. Seawater intakes of cogeneration plants are usually disinfected by chlorine gas or sodium hypochlorite solution. The dose of disinfectant is designed according to the level of contamination of the open seawater in the vicinity of the plant intake. Higher temperature levels, lower pH, reduced flow velocity and oxidation potential play an important role in the enhancement of microbial induced corrosion and bio-fouling. This paper describes, in brief, the different types of bacteria, mechanisms of microbiological induced corrosion, susceptibility of different metal alloys to MIC and possible solutions for mitigating this problem in industry. A case study is presented for the power plant steam condenser at Al-Taweelah B-station in Abu Dhabi. The study demonstrates resistance of Titanium tubes to MIC.

• 한국간호교육학회지
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• 제23권1호
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• pp.5-14
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• 2017

Purpose: The purpose of this study was to examine the effects of the mental health promotion program based on Positive Psychology for adolescents with problem behavior. Methods: The study used a nonequivalent control group pretest-posttest design. Eligible participants were first grade students in two high schools in K Province. The inclusion criteria for the study were those with scores in the upper 15% on the Korean Youth Self-Report. A total of 74 participants were assigned to an 8-session program (n=38) or to a control (n=36) group. The outcome variables were psychological well-being, depression, and self-esteem. Results: There were no statistically significant differences in demographic variables or outcome variables, except self-esteem, between the two groups at the baseline. The experimental group had higher mean scores on psychological well-being and self-esteem and a lower mean score on depression. There were significant differences in psychological well-being (t=3.45, p=.001), self-esteem (F=5.45, p=.022), and depression (t=-2.80, p=.007) between the two groups. Conclusion: The mental health promotion program based on Positive Psychology was effective in decreasing depression as well as improving psychological well-being and self-esteem for adolescents with problem behavior. This study contributes to suggesting a framework for promoting mental health for high school students with problem behavior.

• BMB Reports
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• 제54권2호
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• pp.124-129
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• 2021

In current times, obesity is a major health problem closely associated with metabolic disease such as diabetes, dyslipidemia, and cardiovascular disease. The direct cause of obesity is known as an abnormal increase in fat cell size and the adipocyte pool. Hyperplasia, the increase in number of adipocytes, results from adipogenesis in which preadipocytes differentiate into mature adipocytes. Adipogenesis is regulated by local and systemic cues that alter transduction pathways and subsequent control of adipogenic transcription factors. Therefore, the regulation of adipogenesis is an important target for preventing obesity. Myonectin, a member of the CTRP family, is a type of myokine released by skeletal muscle cells. Although several studies have shown that myonectin is associated with lipid metabolism, the role of myonectin during adipogenesis is not known. Here, we demonstrate the role of myonectin during adipocyte differentiation of 3T3-L1 cells. We found that myonectin inhibits the adipogenesis of 3T3-L1 preadipocytes with a reduction in the expression of adipogenic transcription factors such as C/EBPα, β and PPARγ. Furthermore, we show that myonectin has an inhibitory effect on adipogenesis through the regulation of the p38 MAPK pathway and CHOP. These findings suggest that myonectin may be a novel therapeutic target for the prevention of obesity.

• 대한수학회보
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• 제57권4호
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• pp.1003-1031
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• 2020

We consider the following Dirichlet initial boundary value problem with a gradient absorption and a nonlocal source $$\frac{{\partial}u}{{\partial}t}-div({\mid}{\nabla}u{\mid}^{p-2}{\nabla}u)={\lambda}u^k{\displaystyle\smashmargin{2}{\int\nolimits_{\Omega}}}u^sdx-{\mu}u^l{\mid}{\nabla}u{\mid}^q$$ in a bounded domain Ω ⊂ ℝ^N, where p > 1, the parameters k, s, l, q, λ > 0 and µ ≥ 0. Firstly, we establish local existence for weak solutions; the aim of this part is to prove a crucial priori estimate on |∇u|. Then, we give appropriate conditions in order to have existence and uniqueness or nonexistence of a global solution in time. Finally, depending on the choices of the initial data, ranges of the coefficients and exponents and measure of the domain, we show that the non-negative global weak solution, when it exists, must extinct after a finite time.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제16권2호
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• pp.231-238
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• 2005

연구목적 : 우리나라 청소년들에서 성주체성 혼란과 동성애 성향의 빈도를 우선 파악하고자 하였으며, 성주체성의 혼란이나 동성애 성향을 보이는 청소년들이 성개방성과 자아 존중감에서 그렇지 않은 청소년들과 차이를 보이는지에 대해 알아보고자 하였다. 방법 : 서울지역 1,748명의 중, 고등학생(남자 중학생 359명, 여자 중학생 452명, 남자 고등학생 483명, 여자 고등학생 454명)을 대상으로, 성주체성, 동성애 성향, 성개방성, 자아 존중감에 대하여 자기 보고식 평가척도를 사용하여 측정하였다. 결과 : 1) 남중생의 $15\%$, 남고생의 $16.7\%$, 여중생의 $39.4\%$, 여고생의 $40.5\%$에서 성주체성 문제의 가능성을 보였다. 경미한 성주체성 문제는 여학생에서 많았으나 성주체성장애가 우려되는 심각한 성주체성 혼란은 남자, 특히 남고생에서 많았다. 2) 성주체성 문제 유무에 따른 성개방성은 여중생에서 만이 성주체성 문제군에서 성개방성이 높았고(p=0.044), 자아존중감은 성주체성 문제군에서 낮았는데, 특히 남중생(p=0.033), 여고생(p=0.020)에서는 통계적으로 유의하게 낮았다. 3) 남중생의 $17.2\%$, 남고생의 $5.4\%$, 여중생의 $17.7\%$, 여고생의 $12\%$에서 동성애적 성향이 있었다. 심각한 동성애 성향은 여중생 $3.3\%$, 남중생 $3.1\%$, 여고생 $2.1\%$, 남고생 $1.7\%$순이었다. 4) 동성애 성향 유무에 따른 성개방성 차이는 없었고, 자아존중감은 여고생의 경우만 동성애 성향이 있는 군에서 통계적으로 유의하게(p=0.039) 낮았다. 5) 성주체성 문제가 있는 경우에 통계적으로 유의하게(p=0.001) 동성애 성향이 많았다. 6) 성주체성은 연령간 차이가 없었으나 동성애 성향은 특히 남학생에서 연령이 증가하면서 감소하였다. 결론 : 성주체성의 문제나 동성애 성향을 보이는 청소년에서 자아존중감이 낮았다. 따라서 보다 체계적인 방법으로 이들을 선별하여 적절한 정신과적 조치를 취하는 방안이 요구된다.

• 대한간호학회지
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• 제44권5호
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• pp.495-503
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• 2014

Purpose: The purpose of this study was to identify factors affecting the social competence of school-aged children according alcohol consumption by their parents. Methods: The participants were 558 5th grade elementary school students. Data were collected using structured questionnaires from September 17 to October 2 2013, and analyzed using descriptive statistics, ${\chi}^2$-test, t-test, ANOVA, Pearson correlation coefficients, and Stepwise multiple regression analysis with the SPSS PC+ 21.0 program. Results: Participants were classified into three groups according to alcohol use; Non-use parent group (52.7%), social use parent group (31.0%), and problem use parent group (16.3%). Participants whose parents were problem users had significantly lower scores on emotional awareness and expression (F=14.45, p<.001), social support (F=5.82, p=.003), and social competence (F=16.33, p<.001) compared to students in the other two groups. In school-aged children with parents who were alcohol abusers, the variables that predicted social competence was friend support (66.0%). Conclusion: These results emphasize the importance of focusing on the crucial role of peer support in the development of social competence in school-aged children of parents who abuse alcohol. Further, for these children, interventions aimed at improving social support and children's emotional awareness and expression may be most beneficial.

• 센서학회지
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• 제19권5호
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• pp.391-397
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• 2010

This paper proposes a differential structure sensor for detecting Ringer's solution exhaustion, in which three C-type electrodes of 10 mm width are disposed on a ringer hose at a distance of 5 mm each other in the direction of Ringer's solution flow. In the center of middle electrode, two capacitances are formed at the proposed sensor. When ringer hose is filled with Ringer's solution, there is no difference between two capacitances. But capacitance difference exist under the Ringer's solution shortage, because the shortage causes the hose filled with air from the top position electrode. The capacitance difference got to maximum 1.81 pF, when air was filled between top and middle electrode and the last of hose was filled with 10 % dextrose injection Ringer's solution. The capacitance difference varied with hose-wraparound coverage of electrodes as well as the width of them. For hose-wraparound electrode coverage of 90 % and 70 %, the maximum capacitance difference was 1.81 pF and 1.56 pF, respectively. A differential charge amplifier converted the capacitance difference to electric signal, and minimized electrodes' adhering problem and external noise coupling problem.

• Asian Pacific Journal of Cancer Prevention
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• 제17권9호
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• pp.4275-4279
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• 2016

Background: Cancer is a major health problem due to the aging population with increasing deaths. Family functioning is affected by cancer diagnosis and treatment. The aim of this study was to comparative analysis of the perception of family functioning by heads of families with and without cancer members during illness, focusing on changes or probable changes. Materials and Methods: This comparative study was conducted on two groups (families with a member of the cancer and controls without a family member with cancer). The families were of patients referred to the clinics and hospitals of Imam Khomeini, Taleghani and Omid of Urmia city, the number of samples being 148 for cases and 176for the control group. To collect the data, valid and reliable family functioning (FAD) was applied, a 60-item questionnaire with seven dimensions, with heads of families. To analyze the data SPSS- 23 Software was used for descriptive and analytical statistics. Significance level was defined p <0.05. Results: Among the seven items : problem solving, communication, roles, emotional response, emotional involvement, behavior control and overall functioning, only differences for average scores of problem-solving were statistically significant. Discussion: Contrary to common perception of severe damage for family functioning in families with cancer members, results of this study indicate that functioning in terms of family caregivers is more or less similar to that of the families with other diseases. Only in problem-solving item do these families experience more difficulty. Conclusion: According to the research findings, in nursing from families with cancer patient, it is recommended to focus more on the problem-solving item of the families.

• 한국간호교육학회지
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• 제27권2호
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• pp.210-222
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• 2021

Purpose: This study was conducted to develop and test the effects of a nursing information literacy competency education program for undergraduate nursing students. Methods: A non-equivalent control group pretest-posttest design was used. The subjects consisted of 42 sophomore undergraduate nursing students who had completed a fundamental nursing course (experimental group: n=21, control group n=21). The nursing information literacy competency education program consisted of 8 steps in 8 sessions, taught over 4 weeks, which was 20 hours in total. Data were collected between January 23 and March 14, 2019 and were analyzed using Chi-square test, Fisher's exact test, t-test, paired t-test, and repeated measure ANOVA with SPSS/WIN 23.0. Results: Significant differences were shown between the experimental and control groups regarding nursing information literacy competency (F=91.74, p<.001), problem-solving ability (F=52.43, p<.001), self-directed learning ability (F=36.61, p<.001), and evidence-based practice competency (F=59.66, p<.001). Conclusion: The nursing information literacy competency education program was effective in improving the nursing information literacy competency, problem-solving ability, self-directed learning ability, and evidence-based practice competency of nursing students. Hence, we recommend the nursing information literacy education program will be included as an independent course in the nursing curriculum for undergraduate nursing students to promote a needed proficiency in nursing information literacy competency.