• 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.

• Korean Journal of Social Welfare
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• v.56 no.2
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• pp.145-166
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• 2004

The purpose of this study is to offer information needed in developing mental health service programs which can help mental patients to improve their self-esteem. For that purpose, the difference and the interrelation between mental patients' characteristics, and their self-esteem, group consciousness and consciousness of right were examined. And also, in practice, I observed 374 patients suffering from mental problem, who live in Busan and in Kyeong Nam province. As the result, the several facts which could be got from this theoretical examination and practical observation are as follows: First, it is shown that what is meaningfully related to mental patients' self-esteem are their educational level, the families' monthly earnings, a feeling of satisfaction to family relationship, the time spending together with their friends, or a feeling of satisfaction to their friends Second, it is appeared that there was a significant interaction between group consciousness of mental patients, and whether they have got married and the time spending together with their friends. Third, it is found out that their feeling of satisfaction to family relationship and the time spending together with their friends have meaningful relation to consciousness of right which mental patients have. Finally, speaking of interaction among self-esteem, group consciousness and consciousness of right, it is understood that self-esteem has significant effect of group consciousness, and that group consciousness has confidential effect on consciousness of right.

• Korean Journal of Occupational Health Nursing
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• v.17 no.1
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• pp.23-33
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• 2008

Purpose: The purpose of the study was to identify attitudes of middle managers toward employees with psychological problems and to determine factors affecting their attitudes. Methods: A questionnaire with Community Attitudes Toward Mentally Ill (CAMI) scales was administered to 161 middle managers working in small and medium-sized enterprises based in Seoul and Gyeonggi Province. Results: There are four separate subscales on the CAMI. Mean score for authoritarianism was $35.0{\pm}4.4$, benevolence $23.0{\pm}4.8$, social restrictiveness $32.3{\pm}4.9$ and community mental health ideology $27.2{\pm}5.1$ According to multiple regression analysis, middle managers with no experience of learning mental illness through mass media or higher levels of depression symptom were more authoritative and less benevolent towards employees with psychological problems. The experience of meeting a patient with mental problem contribute to positive attitudes toward people with mental illnesses in social restrictiveness subscale and community mental health ideology subscale among CAMI. Conclusion: This study suggests that experience of having patients with mental problems and information on psychological problems will have great influence on attitudes of middle managers toward employees with psychological problems. It might be important to help middle manager manage their depression because their depression also affects their attitudes toward employees with psychological problems.

• Korean Journal of Environment and Ecology
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• v.26 no.1
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• pp.11-38
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• 2012

Located in the middle part of the Korean peninsula, Pyeong-chang and Yeong-wol (Gangwon-do) areas are limestone regions that are important biogeographically showing the peculiar flora. In order to manage efficiently endangered and rare plant species, we have investigated flora of these above regions from March to October, 2010. The result of the investigation showed a total of vascular plants of 1,145 taxa; 134 families, 503 genera, and 1,010 species, 11 subspecies, 110 varieties, 10 forms and four hybrids. Among taxa investigated, endangered species designated by the law called 'Protection Law for Endangered wild fauna and flora' were seven taxa, and 50 taxa were considered to be endemic to Korea. Based on the floristic degrees categorized by the specific distribution of plant species, 24 taxa revealed the floristic degree (FD) V, 30 for FD IV, and 60 for FD III, 45 for FD II and 79 taxa for FD I. The 82 taxa were identified to be naturalized. Of those species investigated in this survey, 53 taxa were identified as specific ones biogeographically as compared to flora of other terrestrial regions; 35 of calcicolous plants, 15 with distribution in the northern part of the Korean peninsula, three with coastal habitats.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.3 no.2
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• pp.153-169
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• 1996

This study was designed to identify, describe and classify orientations of cancer patient's family members to death and to identify factors related to their attitudes on death. Death to the male is understood as a comprehensive system and believed to be highly subjective experience. Therefore attitude on death is affected by personalities. As an attempt to measure the subjective meaning toward death, the unstructured Q-methodology was used. Korean Death Orientation Questonaire prepared by Kim was used. Item-reliability and Sorting-reliability were tested. Forty five cancer patients' family members hospitalized in one university medical center in Seoul were sampled. Sorting the 65 Q-itmes according to the level of personal agreement ; A forced normal distribution into the 11 levels, were carried out by the 45 P-samples. The demographic data and information related to death orientation of the P-sample was collected through face to face in depth interviews. Data was gathered from August 30 till September 22, 1995. The Z-scores of the Q-items were computed and principal component factor analysis was carried out by PC-QUANL Program. Three unique types of the death orientation were identified and labeled. Type I consists of twenty P-samples. Life and death was accepted as people's destiny, They firmly believed the existence of life after life. They kept aloof from death and their concern was facing the and of the life with dignity, They were in favor of organ donation. Type II consists of Nine P-Samples. They considered that death was the end of everything and did not believed the life after life. They were very concerned about the present life. Type III consists of Sixteen P-samples. They regarded the death as a natural phenomena. And they considered that the man is just a traveller and is bound to head for the next life which is believed to be free of agony, pain or darkness. They neither feared death nor its process. Their conserns were on the activities to prepare themselves for the eternal-life after death. Thus, it was concluded that there were three distinctiven type of attitudes on death among cancer patient family members, and their death attitudes were affected by demographic and socio-cultural factors such as sex, education, and religion.

• Publications of The Korean Astronomical Society
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• v.21 no.2
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• pp.67-74
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• 2006

We have developed a control electronics system for an infrared detector array of KASINICS (KASI Near Infrared Camera System), which is a new ground-based instrument of the Korea Astronomy and Space science Institute (KASI). Equipped with a $512{\times}512$ InSb array (ALADDIN III Quadrant, manufactured by Raytheon) sensitive from 1 to $5{\mu}m$, KASINICS will be used at J, H, Ks, and L-bands. The controller consists of DSP(Digital Signal Processor), Bias, Clock, and Video boards which are installed on a single VME-bus backplane. TMS320C6713DSP, FPGA(Field Programmable Gate Array), and 384-MB SDRAM(Synchronous Dynamic Random Access Memory) are included in the DSP board. DSP board manages entire electronics system, generates digital clock patterns and communicates with a PC using USB 2.0 interface. The clock patterns are downloaded from a PC and stored on the FPGA. UART is used for the communication with peripherals. Video board has 4 channel ADC which converts video signal into 16-bit digital numbers. Two video boards are installed on the controller for ALADDIN array. The Bias board provides 16 dc bias voltages and the Clock board has 15 clock channels. We have also coded a DSP firmware and a test version of control software in C-language. The controller is flexible enough to operate a wide range of IR array and CCD. Operational tests of the controller have been successfully finished using a test ROIC (Read-Out Integrated Circuit).

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.4
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• pp.492-498
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• 2018

This study was conducted to investigate the characteristics of subculture times in the early, middle, and late passages by measuring the time under subculture until it was judged that the supernumerary tooth-derived pulp stem cells (sDPSCS) were no longer proliferating. Three supernumerary teeth from two healthy six-years old boys were extracted and stem cells were obtained from the pulp tissue. This was called SNT1 (supernumerary tooth 1), SNT2, and the supernumerary tooth from another child was named SNT3. SNT1 and 2 were subcultured at the same time and SNT3 was subcultured a little faster. The mean time of complete subculture was $3.6{\pm}1.1$ days. Total passages were cultured up to $23.3{\pm}0.6$ and took 83 days. These were divided into three groups based on the passage. The increase rate of time taken in subculture between group I and group II was 11.9%, but the rate between group II and group III was 28.6%, which was 2.4 times increased. The time taken between passages during long-term subculture up to 22 passages shows a regressive pattern y = 0.1169x + 2.25 and y = 0.1169x + 2.0. In conclusion, the passage time of SPSCs increased in late passages, and it shows a similar pattern.

• Korean Journal of Plant Resources
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• v.21 no.5
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• pp.374-387
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• 2008

This study was carried out to investigate the distribution of the useful resources plants and the flora of the sand dune on South Coast and Jeju Island. The flora of sand dune on South Coast and Jeju Island was investigated from February to November in 2006. Vascular plants of this area consist of total 171 taxa; 1 forma, 18 varieties, 152 species, 130 genera, 51 families. The dominant species in the vegetations of the south coast sand dune were Calystegia soldanella, Ischaemum anthephoroides, Vitex rotundifolia, Carex pumila, Carex kobomugi. It corresponds to 11.1 % of totally 4,071 taxa appeared in Korea. Useful plants of this area were investigated 113 taxa. It corresponds to 66% of collected plants in this area under our study. Among the useful plants, there are 73 taxa of edible source, 61 taxa of medicinal source, 22 taxa of pasture source, 16 taxa of ornamental source, 7 taxa of fiber source, 1 taxa of timber source. Korean endemic plants were composed 1 taxa.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.1
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• pp.91-99
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• 2008

A multilayer tower-type photoreactor, in which $TiO_2$-coated glass-tubes were installed, was used to measure the vapor-phase BTEX removal efficiencies by ozone oxidation ($O_3$/UV), photocatalytic oxidation ($TiO_2$/UV) and the combination of ozone and photocatalytic oxidation ($O_3/TiO_2$/UV) process, respectively. The experiments were conducted under various relative humidities, temperatures, ozone concentrations, gas flow rates and BTEX concentrations. As a result, the BTEX removal efficiency and the oxidation rate by $O_3/TiO_2$/UV system were highest, compared to $O_3$/UV and $TiO_2$/UV system. The $O_3/TiO_2$/UV system accelerated the low oxidation rate of low-concentration organic compounds and removed organic compounds to a large extent in a fixed volume of reactor in a short time. Therefore, $O_3/TiO_2$/UV system as a superimposed oxidation technology was developed to efficiently and economically treat refractory VOCs. Also, this study demonstrated feasibility of a technology to scale up a photoreactor from lab-scale to pilot-scale, which uses (i) a separated light-source chamber and a light distribution system, (ii) catalyst fixing to glass-tube media, and (iii) unit connection in series and/or parallel. The experimental results from $O_3/TiO_2$/UV system showed that (i) the highest BTEX removal efficiencies were obtained under relative humidity ranging from 50 to 55% and temperature ranging from 40 to $50^{\circ}C$, and (ii) the removal efficiencies linearly increased with ozone dosage and decreased with gas flow rate. When applying Langmuir-Hinshelwood model to $TiO_2$/UV and $O_3/TiO_2$/UV system, reaction rate constant for $O_3/TiO_2$/UV system was larger than that for $TiO_2$/UV system, however, it was found that adsorption constant for $O_3/TiO_2$/UV system was smaller than that for $TiO_2$/UV system due to competitive adsorption between organics and ozone.

• Journal of Biosystems Engineering
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• v.27 no.2
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• pp.117-124
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• 2002

This research was conducted to develop a method to remove the effect of surface temperature of Shingo pears for sugar content measurement. Sugar content was measured by a near-infrared spectrum analysis technique. Reflected spectrum and sugar content of a pear were used for developing regression models. For the model development, reflected spectrums having wavelengths in the range of 654 to 1,052nm were used. To remove the effect of surface temperature, special sample preparation techniques and partial least square (PLS) regression models were proposed and tested. 71 Shingo pears stored in a cold storage, which had 2$^{\circ}C$ inside temperature, were taken out and left in a room temperature for a while. Temperature and reflected spectrum of each pear was measured. To increase the temperature distribution of samples, temperature and reflected spectrum of each pear was measured four times with one hour twenty minutes interval. During the experiment, temperature of pears increased up to 17 $^{\circ}C$. The total number of measured spectrum was 284. Three groups of spectrum data were formed according to temperature distribution. First group had surface temperature of 14$^{\circ}C$ and total number of 51. Second group consisted of the first and the fourth experiment data which contained the minimum and the maximum temperatures. Third group consisted of 155 data with normal temperature-distribution. The rest data set were used for model evaluation. Results shelved that PLS model I, which was developed by using the first data group, was inadequate for measuring sugar content of pears which had different surface temperatures from 14$^{\circ}C$. After temperature compensation, sugar content predictions became close to the measured values. Since using many data which had wide range of surface temperatures, PLS model II and III were able to predict sugar content of pears without additional temperature compensation. PLS model IV, which included the surface temperatures as an independent variable. showed slightly improved performance(R$^2$=0.73). Performance of the model could be enhanced by using samples with more wide range of temperatures and sugar contents.