• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.405-405
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• 2010

Thermocouple 을 통해 Inductively coupled plasma 에 노출된 실리콘 기판 표면온도를 공정조건 변화 에 따라 실시간 (in-situ) 측정하였다. 이를 바탕으로 공정변화에 따른 플라즈마 내 활성종의 거동을 연구하였다. 더 나아가 기판의 표면온도변화 및 활성종의 거동해석을 토대로 공정변화에 의한 딥 실리콘 구조형성 메커니즘을 해석하였다. 플라즈마에 노출된 기판표면 온도를 상승시키는 주 활성종은 positive ion 이며 ICP power, Bias power, 플라즈마 압력 변화에 따라 positive ion 의 밀도 및 가속에너지가 변화하는데 이러한 거동변화는 기판의 표면온도를 변화시킴을 알 수 있었다. 딥 실리콘 구조의 측벽 및 바닥에 형성되어 있는 passivaiton layer 즉 $SiO_xF_y$(silicon oxyflouride) 는 온도에 매우 민감한 물질이며 이는 딥 실리콘 구조 내부로 입사하는 positive ion 거동변화에 따라 그 성질이 변화하여 deep Si 구조 형상을 변화시킴을 알 수 있었다. 기판표면 온도가 $0^{\circ}C$ 이하의 극저온으로 유지된 상황에서 플라즈마를 방전할 경우 positive ions 의 가속에너지로 인해 기판표면온도가 상승하며 액화질소 유량증가를 통해 다시 기판의 표면온도를 유지시킬 수 있었다. 이를 통해 플라즈마 방전 전과 방전 후의 기판 표면온도는 상온의 기판뿐만 아니라 극저온의 기판에서도 다름을 알 수 있었다. 냉각환경 변화에 따른 딥 실리콘 구조형성 메커니즘을 positive ions 거동 그리고 온도 감소에 의한 $SiO_xF_y$ 성질 변화를 이용해 해석할 수 있었다.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.1
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• pp.6-11
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• 2023

Objective: This study was conducted to identify the cause of suffocation accident. Methods: We analyzed the components of zinc concentrates by ICP-OES (inductively coupled plasma optical emission spectroscopy) and tested the oxygen consumption by zinc concentrates in a 13.2-liter closed chamber. Results: Zinc, sulfur and iron were the main components of the four types of zinc concentrates, and accounted for 76~89% by weight. Zinc concentrates (0.5 or 0.927 kg) depleted the oxygen concentration from 20.9% to 7.4~18.9% during seven days. The rate of oxygen consumption was in the range of 3.0~11.0 mM/day·kg-sample at 21~24℃ and around 95% of free air space within the closed chamber. Conclusion: Since zinc concentrate consumes oxygen in a confined space, measures should be taken to prevent suffocation accident (such as ventilation and monitoring of oxygen concentration).

• Journal of Korean Society of Environmental Engineers
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• v.22 no.1
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• pp.33-42
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• 2000

Adsorption onto the surfaces of solid particles is a well known phenomenon that causes the retardation effect of heavy metals in soils. For adequate remediation of soil and groundwater contamination, it is important to investigate the mobility of heavy metals that largely depends on pH conditions in the soil water since adsorption of heavy metals is pH-dependent. In this study, we investigated the transport of Zn ion under various pH conditions in a sandy soil by conducting batch and column tests. The batch test was performed using the standard procedure of equilibrating fine fractions collected from the soil with eleven different initial $ZnCl_2$ concentrations, and analysis of Zn ion in the equilibrated solutions using ICP-AES. The column test consisted of monitoring the concentrations of soil solutions exiting the soil column with time known as a breakthrough curve (BTC). We injected respectively $ZnCl_2$ and KCl solutions with the concentration of 10 g/L as a tracer in a square pulse type under three different pH conditions (7.7, 5.8, 4.1) and monitored the flux concentration at the exit boundary using an EC meter and ICP-AES. The resident concentration was also monitored at the 10cm-depth by Time Domain Reflectometry (TDR). The results of batch test showed that ion exchange process between Zn and other cations (Ca, Mg) was predominant. The retardation coefficients obtained from adsorption isotherms (Linear, Freundlich, Langmuir) resulted in the various values ranging from 1.2 to 614.1. No retardation effect but ion exchange was found for the BTCs under all pH conditions. This can be explained by the absence of other cations to desorb Zn ion from soil exchange sites under the conditions of ETC experiment imposing blank water as leachate in steady-state flow. As pH decreased, the peak concentration of Zn increased due to the competition of Zn with hydrogen ions ($H^+$) and the concentrations of other cations decreased. The peak concentration of Zn was increased by 12.7 times as pH decreased from 7.7 to 4.1.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.5
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• pp.583-589
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• 2002

The Internet is absolutely contributed to information telecommunication revolution nowadays. Realizing local network at the various type of buildings such as a company and a university, ethernet is used for subnet and FDDI, ATM are used for backbone mainly in order to get internet services. Processing TCP/IP protocol suite and analyzing the protocol exactly is essential to detecting the problem occurring in the network and developing communication equipment. This paper presents implementation of ethernet LAN protocol analyser which monitors and simulates ICP/IP protocol suite carrying the Internet and non-Internet protocol such as Netware and NetBIOS. MS window98 and visual C are used for development environment and application program operates on the NDIS firmware. The performance analysis on the proposed system is carried out as monitoring and simulating the traffic over LAN of a university. In the result of monitoring the system, the processing time of a packet captured over the LAN is about 1.5ms. In case of simulating the system, the processing time to be taken carrying out TCP connection and disconnection once is packet is about 8.6ms. The performance analysis of monitoring and simulation results satisfies with 10 Mbps ethernet LAN environment.

• Journal of Food Hygiene and Safety
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• v.31 no.6
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• pp.420-425
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• 2016

The present study aimed to calcium (Ca), iron (Fe) and zinc (Zn) contents were compared with reference values indicated on the nutrition label of nutrition emphasized food. Also, this paper will briefly review and evaluate what is currently known about Fe-Zn and Ca-Fe interaction. Ca, Fe or Zn-emphasized product, including cereal, snack, soy milk, chocolate product, other cocoa product, sugars product, beverage and tea were analyzed. The contents of Ca, Fe, and Zn in samples after dry-ashing were examined by ICP. The measured Ca (n = 42), Fe (n = 13), Zn (n = 6) values were ranged 87~176%, 98~167%, 98~275% of reference value indicated product, respectively. All samples were ranged more than 80% of the reference value, which were complied with food regulation. High intake of Ca has been shown to adversely affect Fe absorption and the negative effect of Fe on Zn absorption is well known. Therefore, it is important to consider Ca-Fe and Fe-Zn absorption interaction, when Ca, Fe or Zn-emphasized product produce and nutrition labeling policy should be managed regularly with continuous monitoring.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.466-475
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• 2017

The purpose of this study was to investigate the status of infection control in long term care hospitals. Data were gathered from 156 long term care hospitals that received certification evaluation from May 1, 2016 to July 31, 2016. We used a questionnaire consisting of 85 items regarding the status and perceived importance of infection control. The data were analyzed using the SPSS / WIN 21.0 program. All of the hospitals have infection control regulations, 80.4% of them have an infection control committee and 86.0% of them employ an ICP(infection control practitioner) who holds this position in addition to another. Hand hygiene showed the highest score at 4.47 in the perceived importance of infection control. Employee education and compliance with the validity period of sterilized products showed the highest frequency and perceived importance among the infection control activities. The above results show that almost all of the long term care hospitals have infection control regulations, but that these regulations are not properly implemented, because of the lack of applicable regulations on the policy level. Therefore, it is necessary to develop infection monitoring standards and infection control guidelines for long term care hospitals and provide the infection control practitioners with training in how to apply them.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.1
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• pp.15-21
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• 2022

The purpose of our study was to investigate the migration level of lead (Pb), cadmium (Cd), and barium (Ba) from glassware into a food simulant and to evaluate the exposure of each element. The test articles were glassware, including tableware, pots, and other containers. Pb, Cd, and Ba were analysed by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The analytical performance of the method was validated in terms of its linearity, limit of detection (LOD), limit of quantification (LOQ), recovery, precision, and uncertainty. The monitoring was performed for 110 samples such as glass cups, containers, pots, and bottles. a food simulant. Migration test was conducted at 25? for 24 hours in a dark place using 4% acetic acid as a food simulant. Based on the data; exposure assessment was carried out to compare the estimated daily intake (EDI) to the human safety criteria. The risk levels of Pb and Ba determined in this study were approximately 1.9% and 0.3% of the provisional tolerable weekly intake (PTWI) and tolerable daily intake (TDI) value, respectively, thereby indicating a low exposure to the population.

• Journal of Food Hygiene and Safety
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• v.33 no.4
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• pp.240-247
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• 2018

This study was carried out to determine the levels of lead and cadmium as found in nine agricultural products (n = 578) sold in Korea, and to estimate the risk to human health that is summarily associated with their intake. The concentrations of Pb and Cd were measured using an ICP-MS after microwave digestion in this study. The average contents of Pb and Cd were measured as 0.014 and 0.017 mg/kg for barley, 0.006 and 0.005 mg/kg for mung bean, 0.008 and 0.007 mg/kg for kidney bean, 0.010 and 0.004 mg/kg for green bean, 0.008 and 0.001 mg/kg for pineapple, 0.016 and 0.002 mg/kg for apricot, 0.015 and 0.002 mg/kg for Japanese apricot, 0.021 and 0.002 mg/kg for plum and 0.019 and 0.003 mg/kg for jujube, respectively. The levels of Pb and Cd in the study samples were less than the maximum residual levels established by the European Union (EU), CODEX, and the Korea Food Code. As we have seen, the daily dietary exposures of Pb and Cd from these agricultural products for the general population were noted as 0.067% of PTWI ($25{\mu}g/kg$ b.w./week) and 0.28% of PTMI ($25{\mu}g/kg$ b.w./month), respectively. In line with the study conclusions, these results suggest that the current dietary intakes of Pb and Cd from these agricultural products in Korea have no appreciable risk effects on health for humans as noted in this experiment.

• Microbiology and Biotechnology Letters
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• v.26 no.6
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• pp.537-544
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• 1998

The cultivation conditions of transformant Alcaligenes eutrophus AER5 harboring cloned phbC gene for mass production of poly (3-hydroxybutyrate-3-hydroxyvalerate)[P(3HB-3HV)] containing high molar fraction of 3-hydroxyvalerate (3-HV) were investigated. In two-stage batch cultivation, transformant accumulated P(3HB-3HV) containing 52.2 mol% of 3HV compared to 30 mol% of parent strain A. eutrophus H16. The increased 3-HV molar fraction was due to the amplified activity of PHB synthase participating in condensation of 3-HB and 3-HV. To increase efficiency of P(3HB-3HV) accumulation, fructose was added along with precursor compound valerate, and total cell mass and P(3HB-3HV) concentrations remarkably increased, but not 3-HV molar fraction. The effect of magnesium ion showed that P(3HB-3HV) concentration and 3-HV molar fraction were significantly increased upto 6.1 g/L and 71.3 mol% at 0.01 g/L of MgSO$_4$, respectively. The efficiency of several pH adjuster, NaOH, NaOH and (NH$_4$)$_2$SO$_4$, and NH$_4$OH, on total cell mass, p(3HB-3HV) concentration, and 3-HV molar fraction was also compared. To overcome the disadvantage of two-stage cultivation, one-stage intermittent fed-batch cultivation was attempted, such a way 10.0 g/L of fructose was supplied for cell growth at initial 36 hr and then 10.0 g/L of valerate and 5.0 g/L of fructose were applied to induce the accumulation of P(3HB-3HV), consequently, 10.4 g/L of P(3HB-3HV) with 38 mol% of 3-HV fraction could be obtained after 72 hr. These results can be used for elucidating cultivation strategy for mass production of P(3HB-3HV) containing high 3-HV molar fraction using transformant A. eutrophus AER5 harboring cloned phbC gene.

• Korean Journal of Food Science and Technology
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• v.41 no.3
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• pp.238-244
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• 2009

This survey was conducted as a surveillance program following the establishment of safety guidelines for agricultural products in Korea. Concentrations of arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg) were measured in 421 samples using a mercury analyzer or ICP-MS. The average levels of Pb in mg/kg were 0.021 for rice, 0.020 for corn, 0.028 for soybeans, 0.034 for red beans, 0.025 for sweet potatoes, 0.021 for potatoes, 0.019 for Chinese cabbage, 0.031 for spinach, 0.021 for Welsh onions, and 0.011 for radishes. The average levels of Cd in mg/kg were 0.021 for rice, 0.002 for corn, 0.020 for soybeans, 0.006 for red beans, 0.008 for sweet potatoes, 0.011 for potatoes, 0.007 for Chinese cabbage, 0.035 for spinach, 0.006 for Welsh onions, and, 0.006 for radishes. The average levels of As in mg/kg were 0.103 for rice, 0.005 for corn, 0.007 for soybeans, 0.005 for red beans, 0.005 for sweet potatoes, 0.004 for potatoes, 0.007 for Chinese cabbage, 0.015 for spinach, 0.009 for Welsh onions and, 0.006 for radishes. Finally, the average levels of Hg in ${\mu}g/kg$ were 2.3 for rice, 0.2 for corn, 0.6 for soybeans, 1.4 for red beans, 0.1 for sweet potatoes, 0.3 for potatoes, 0.5 Chinese cabbage, 2.1 for spinach, 0.5 for Welsh onions, and 0.2 for radishes. Based on the Korean public nutrition report 2005, these levels (or amounts) are calculated only at 2.6% for Pb, 8.7% for Cd, 1.2% for Hg of those presented in provisional tolerable weekly intake (PTWI) which has been established by FAO/WHO. Therefore, the levels presented here are presumed to be adequately safe.