• Carbon letters
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• v.23
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• pp.38-47
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• 2017

In this study, magnetite ($Fe_3O_4$) nanoparticles were electrochemically synthesized in an aqueous electrolyte at a given potential of -1.3 V for 180 s. Scanning electron microscopy revealed that dendrite-like $Fe_3O_4$ nanoparticles with a mean size of < 80 nm were electrodeposited on a glassy carbon electrode (GCE). The $Fe_3O_4/GCE$ was utilized for sensing chloramphenicol (CAP) by cyclic voltammetry and square wave voltammetry. A reduction peak of CAP at the $Fe_3O_4/GCE$ was observed at 0.62 V, whereas the uncoated GCE exhibited a very small response compared to that of the $Fe_3O_4/GCE$. The electrocatalytic ability of $Fe_3O_4$ was mainly attributed to the formation of Fe(VI) during the anodic scan, and its reduction to Fe(III) on the cathodic scan facilitated the sensing of CAP. The effects of pH and scan rate were measured to determine the optimum conditions at which the $Fe_3O_4/GCE$ exhibited the highest sensitivity with a lower detection limit. The reduction current for CAP was proportional to its concentration under optimized conditions in a range of $0.09-47{\mu}M$ with a correlation coefficient of 0.9919 and a limit of detection of $0.09{\mu}M$ (S/N=3). Moreover, the fabricated sensor exhibited anti-interference ability towards 4-nitrophenol, thiamphenicol, and 4-nitrobenzamide. The developed electrochemical sensor is a cost effective, reliable, and straightforward approach for the electrochemical determination of CAP in real time applications.

• Journal of the Korean Geotechnical Society
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• v.21 no.5
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• pp.187-196
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• 2005

Since the allowable bearing capacities of piles in weathered/fractured rock are mainly governed by settlement, the load-displacement behavior of pile should be known accurately. To predict pile head settlement at the design stage, the exact understanding of the load-transfer mechanisms is essential. Therefore, in this research, the load-transfer mechanism of drilled shaft socketed into weathered rock was investigated. For the investigation, five cast-in-place concrete piles with diameters of 1,000 mm were socketed into weathered gneiss. The static axial load tests and the load-transfer measurements were performed to examine the axial resistant behavior of the piles. A comprehensive field/laboratory testing program on weathered rock at the Held test sites was also performed to describe the in situ rock mass conditions quantitatively. And then, the effect of rock mass condition on the load transfer mechanism was investigated. The f-w (side shear resistance-displacement) curve of the pile in moderately weathered rock reached to yielding point at a for millimeter displacements, and after yielding point, the rate of resistance increment dramatically decreased. However, the f-w curve in the highly/completely weathered rock did not show the obvious yielding point, and the resistance gradually increased showing the hyperbolic pattern until relatively high displacement (>15 mm). The q-w (end bearing resistance-displacement) curves showed linear response at least until the base displacement of approximately 10 mm, regardless of rock mass conditions.

• Journal of dental hygiene science
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• v.6 no.1
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• pp.47-53
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• 2006

This study is performed both for notification of knowledge level about water fluoridation program for residents of Haeundae, Busan and for finding out the purpose of solving methods of problems which could appeared in water fluoridation program, it has resulted by the survey of 460 Haeundae citizens from August 5, 2005 thru 20th of same month. 1. The drinking water for Haeundae Residents is occupied of 42.8% of the purified water and 31.3% of public tap water, among these, the cooking water is consist of 48.3% of the tap water and 35.4% of the purified water. 2. 35.7% of participants has already known about the water fluoridation program, but 42.0% hasn't, 22.4% were no answer. 3. For the question why water fluoridation program has done 42.0% answered for caries prevention, 32.3% for disinfection of tap water and 15.0% for tap water purification. 4. For water fluoridation program, 78.0% approved and 22.0% disapproved, among reasons 51.0% of approvals were caries prevention and 38.6% of disapproval were that fluorine can be harmful for the human body. 5. There is a fact that fluorine is contained in food, beverage, water, and air, only 21.3% has notified that fact, on the other hand 78.7% hasn't, among teens, 93.5% doesn't know the fluorine containing facts. 6. In the safety notification rate of water fluoridation program, 39.3% notifies it safe, 55.7% showed unknown response, and the speech 28.3% may be the best way to notify it.

• Journal of Haehwa Medicine
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• v.8 no.1
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• pp.865-878
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• 1999

With advances in neonatal medicine, smaller and sicker infants are surviving premature birth. As these tiny patients battle for their lives, their parents also struggle with psychological consequences of an unexpected role. The birth of a sick infants has long been documented as stressful events for the parents. High stress levels may alter parents' interaction with their baby and impair their communication with health professionals, which can in turn affect parents' participation in care planning and decision making. Nursing interventions aimed at reducing the parental stress and anxiety levels during this crisis may have a positive impact on their ability to form an attatchment to their baby and make prudent decisions about his care. The planning of such interventions would be inhanced if the contributions of various factors to increased parental stress levels were identified. This descriptive study was conducted to understand the contents and degree of parental stress in the NICU during their premature's hospitalization, and to give a baseline data in developing nursing intervention program. Subjects were the 60 mother of hospitalized newborn in NICU of 2 University Hospital in Taejon City from April 1st, 1999 to June 30th, 1999, who agreed to take part in this study. The instrument used in this study were Parental Stressor Scales:NICU(PSS:NICU) developed by Miles et al.. and validated by 3 NICU practitioners and 3 child health nursing faculties. The questionnaire has 4 dimensions and 45 items; sight and sounds of NICU(5 items), babies' appearance and behavior nursing intervention(19 items), parental role alteration and relationship with their baby(10 items), health team communication(11 items). The questionnaire asks parents to rate each item on a five-point Likert type scale that ranges from "not stressful" (1) to "extremely stressfu1"(5). Total scores representing overall stress from the NICU environment are calculated by summing response to each item. A high score indicates high stress. A subscale score is calculated by summing the responses to each item in the subscale. Cronbach's ${\alpha}$ coefficients were .93. The data was analyzed as average, Frequency, Standard deviation, t-test, ANOVA, Pearson correlation coefficient by use of SPSS/PC+. The results of this study is summarized as follows ; 1. The total perceived stress level score of mothers of premature baby was slightly high($3.66{\pm}1.1$). The highest scored dimension was 'relationship with their baby and parental role change'($4.21{\pm}0.9$), and next were 'appearance and behavior of the baby'($3.92{\pm}1.1$), 'communication with health team'($3.32{\pm}1.3$), 'sight and sounds of NICU'($3.30{\pm}1.1$). 2. There were statistically significant correlation noted ; mother's perceived severity of the baby's condition(F=8.0012, P= .0125) and baby's gestational age(r = -.4724, P = .0500). In summary, information about physical environment of NICU, the mother's perceived severity of premature baby's state, maternal role change related variables and the knowledge of characteristics of premature baby must be included in nursing intervention program of mother's of premature baby in reducing the parental stress and anxiety level. It is suggested that each NICU needs to develop a nurse managed supportive care program for parents of premature baby. Also, it is suggested that there need to investigate the coping mechanism of mother of premature baby.

• Ocean Systems Engineering
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• v.6 no.1
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• pp.61-97
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• 2016

This is the second of two papers on the 3D numerical modeling of nearshore hydro- and morphodynamics. In Part I, the focus was on surf and swash zone hydrodynamics in the cross-shore and longshore directions. Here, we consider nearshore processes with an emphasis on the effects of oceanic forcing and beach characteristics on sediment transport in the cross- and longshore directions, as well as on foreshore bathymetry changes. The Delft3D and XBeach models were used with four turbulence closures (viz., ${\kappa}-{\varepsilon}$, ${\kappa}-L$, ATM and H-LES) to solve the 3D Navier-Stokes equations for incompressible flow as well as the beach morphology. The sediment transport module simulates both bed load and suspended load transport of non-cohesive sediments. Twenty sets of numerical experiments combining nine control parameters under a range of bed characteristics and incident wave and tidal conditions were simulated. For each case, the general morphological response in shore-normal and shore-parallel directions was presented. Numerical results showed that the ${\kappa}-{\varepsilon}$ and H-LES closure models yield similar results that are in better agreement with existing morphodynamic observations than the results of the other turbulence models. The simulations showed that wave forcing drives a sediment circulation pattern that results in bar and berm formation. However, together with wave forcing, tides modulate the predicted nearshore sediment dynamics. The combination of tides and wave action has a notable effect on longshore suspended sediment transport fluxes, relative to wave action alone. The model's ability to predict sediment transport under propagation of obliquely incident wave conditions underscores its potential for understanding the evolution of beach morphology at field scale. For example, the results of the model confirmed that the wave characteristics have a considerable effect on the cumulative erosion/deposition, cross-shore distribution of longshore sediment transport and transport rate across and along the beach face. In addition, for the same type of oceanic forcing, the beach morphology exhibits different erosive characteristics depending on grain size (e.g., foreshore profile evolution is erosive or accretive on fine or coarse sand beaches, respectively). Decreasing wave height increases the proportion of onshore to offshore fluxes, almost reaching a neutral net balance. The sediment movement increases with wave height, which is the dominant factor controlling the beach face shape.

• Women's Health Nursing
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• v.7 no.3
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• pp.305-316
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• 2001

The purpose of this study was to identify characteristics related to self assertiveness in teenage girls, and to identify the relationship between the self assertiveness and sexual experiences in teenage girls in Korea. The subjects for this study were 12,733 girls from an accessible population of 19,000 girls who were a multi-stage cluster sample from a population of 1,988,902 girls attending to 4,684 schools in the seven large cities and nine provinces of Korea. The response rate was 68.9%. Data were collected by mail from October 2 to October 28, 2000. A structured questionnaire of 125 items which included measurement of general characteristics, sexual experiences, and self-assertiveness was used. The sexual experiences were defined as dating, holding hands, putting arms on the shoulders, light kissing, French kissing, touching breasts, touching genitalia, and coitus. The self assertiveness measurement was developed by S. B. Chang et al.(2000) and has a Cronbach's alpha of .6031. Data was analyzed with SPSS 10.0 Program using descriptive statistics, reliability, and t-test. The results of this study are as follows; 1. The subjects were from 9th to 11th graders and 42.7% answered that they followed their partner's request. The range for the self assertiveness score was 7-21 out of a possible range of 7-21. The group of girls who were in vocational schools, lived away from family or in rural areas, attended night school, took part in drinking, smoking, and glue inhalation, who had cyber sex or phone sex or were exposed to pornography, and who had run away from home showed significantly lower self assertiveness scores than those without these characteristics (P<.05). 2. The group which had experience in dating(t=2.379, P=.017), French kissing (t=5.425, P=.000), touching breasts (t=8.637, P=.000), touching genitalia (t=6.057, P=.000), and coitus(t=6.057, P=.000) showed significantly lower self assertiveness scores than the group which had not had these sexual experiences. But there was no difference in the self assertiveness scores between the group which had experience of holding hands, light kissing, and using contraceptives compared to the group which did not. It can be concluded that the group which had delinquent behavior showed lower self assertiveness, and the lower self assertiveness led to unwanted sexual experiences. It is suggested that self assertiveness training be provided for the group with delinquent behavior as a first priority, and then analyze of the process of self assertiveness in relation to sexual experiences.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.3
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• pp.672-681
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• 2015

Edwardsiellosis has become a serious diseases problem in cultured eels for many years. This study was performed to investigate possibility of vaccination against edwardsiellosis caused by Edwardsiella tarda. We conducted a immersion and/or oral vaccination using formalin-killed E. tarda in eel Anguilla japonica. Three groups of fish ($26.8{\pm}1.2g$, $7.1{\pm}0.7g$ and $2.2{\pm}0.4g$) were used in this study. The protection (relative percentage survival, RPS) and serum antibody response (agglutination titer) were evaluated in the vaccinated fish. No correlation between agglutination titer and survival rate was observed in vaccinated fish. However, there was a satisfactory protective (RPS>50%) in vaccinated fish. Immersion (10 mg/mL, 1 hr) and immersion (10 mg/mL, 1 hr) plus oral (10 mg/g, 10 days) of $26.8{\pm}1.2g$, immersion (10 mg/mL, 1 hr) plus oral (10 mg/g, 10 days) of $7.1{\pm}0.7g$ showed RPS of 62.6%, 52.2% and 56.8%, respectively.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.40
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• pp.16.1-16.5
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• 2018

Background: Proliferative verrucous leukoplakia (PVL) is an oral potentially malignant disorder, characterized by multifocal expression, progressive clinical evolution, and a high rate of malignant transformation. Evidence-based information regarding optimal PVL management is lacking, due to the paucity of data. The present report describes a case of PVL associated with HPV-16 infection and epithelial dysplasia treated by diode laser surgery, and the outcome of disease clinical remission over a 2-year follow-up period. Case report: A 61-year-old Caucasian male with oral verrucous hyperkeratosis presented for diagnosis. The lesions were localized on the maxillary gingiva and palatal alveolar ridge. Multiple biopsy specimens have been taken by mapping the keratotic lesion area. Microscopic examination was compatible with a diagnosis of PVL with focal mild dysplasia, localized in the right maxillary gingiva. Polymerase chain reaction (PCR) was done for human papillomavirus (HPV) detection which revealed presence of HPV DNA, and the genotype revealed HPV 16 in the sample. The PVL in the right gingival area was treated on an outpatient basis by excision with a diode laser. This approach resulted in good clinical response and decreased morbidity over a 2-year follow-up period. Conclusions: This case illustrates the benefit of a conservative approach by diode laser treatment than wide surgical excision for management of the PVL lesions associated with mild dysplasia and HPV-16 infection.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.3
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• pp.338-350
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• 2007

The objectives of this study were to analyze nutrition-related problems and to develop the nutrition education programs for high school students A survey was conducted with 500 students in the second grade level at high schools in Daegu who differed in socio-economic characteristics. In addition, body composition analysis was accomplished by the Inbody 3.0. The developed questionnaires were distributed and 481 questionnaires were collected with a 96.2% of response rate. Statistical data analysis was completed using SPSS WIN(ver.12.0) for descriptive analysis, reliability analysis, factor analysis, t-tests and $X^2$-tests. We first analyzed students' problems related to nutrition and environmental factors. In a question addressing skipping breakfast, only 11.5% answered they "do not eat" breakfast. In regards to BMI, the male students' degree of obesity was higher. Second, we analyzed living environments, which greatly influence dietary behavior. For the snacks-related categories, most of the students liked bread, cake and other snacks. When they chose the snacks, they mainly considered taste. There were significant difference among the males and females(p<.01) in terms of snacks intake habits, where 43.1 % of the males answered they snack "occasionally" and 43.4% of the females answered they snack "according to how they feel". In the case of beverages, the males consumed significantly more(p<.001). Based on their regional groups, the area A group preferred milk and milk products, and the area B group preferred soft drinks. As for the time of beverage intake, 77.6% of the females answered "with snacks", which was significantly higher than 61.4% of the males(p<.001), 12.2% of the males drank beverages after exercise. For late snacking, 68.0% of the male students and 71.1 % of the female students consumed late snacks. Most of them preferred bread, cake and other snacks. The reasons for taking a late snack were "when I feel hungry" by 61.8% of the males which was higher than the females(p<.001), 23.6% of the females consumed late snacks "impulsively". Ideally, in order to improve the food habits of high school students effective and practical nutrition education programs that consider gender and regional school group, should be carried out.

• Journal of IKEEE
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• v.14 no.2
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• pp.16-23
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• 2010

Since the interest of a brain science research is increased recently, various devices using brain waves have been developed in the field of brain training game, education application and brain computer interface. In this paper, we have developed a portable EEG measurement and a bluetooth based wireless transmission device measuring brain waves from the frontal lob simply and conveniently. The low brain signals about 10~100${\mu}V$ was amplified into several volts and low pass, high pass and notch filter were designed for eliminating unwanted noise and 60Hz power noise. Also, PIC24F192 microcontroller has been used to convert analog brain signal into digital signal and transmit the signal into personal computer wirelessly. The sampling rate of 1KHz and bluetooth based wireless transmission with 38,400bps were used. The LabVIEW programing was used to receive and monitor the brain signals. The power spectrum of commercial biopac MP100 and that of a developed EEG system was compared for performance verification after the simulation signals of sine waves of $1{\mu}V$, 0~200Hz was inputed and processed by FFT transformation. As a result of comparison, the developed system showed good performance because frequency response of a developed system was similar to that of a commercial biopac MP100 inside the range of 30Hz specially.