• Journal of the Semiconductor & Display Technology
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• v.18 no.1
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• pp.1-4
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• 2019

Reactive sputtering is widely used because of its high deposition rate and high step coverage. The deposition layer is often affected by target poisoning because the target conditions are changed, as well, by reactive gases during the initial stage of sputtering process. The reactive gas affects the deposition rate and process stability (target poisoning), and it also leads unintended oxide interlayer formation. Although the target poisoning mechanism has been well known, little attention has been paid on understanding the interlayer formation during the reactive sputtering. In this research, we studied the interlayer formation during the reactive sputtering. A DC magnetron sputtering process is carried out to deposit an aluminum oxide film on a silicon wafer. From the real-time process monitoring and material analysis, the target poisoning phenomena changes the reactive gas balance at the initial stage, and affects the interlayer formation during the reactive sputtering process.

• Journal of agricultural medicine and community health
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• v.9 no.1
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• pp.18-26
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• 1984

With the increase of using pesticides, pesticide poisonings become more frequent. In the previous epidemiological study on pesticide poisoning and the reports of the authorities concerned, it is carefully affirmed that pesticide poisonings are caused by farmers' ignorance and negligence in using the pesticides. But the pesticide poisoning should be taken into account in terms of the person who sprays the pesticides, its spraying process, farming style and farmers' socio-economic conditions. And based on the understanding mentioned above, preventive measures for pesticide poisoning should be established. In this socio-medical point of view, this study examined the public health problems caused by using pesticides and the treatment of pesticide poisoning, based on the interviews with farmers in a area of Kyunggi-Do about the spraying process of pesticides, poisoning experiences and its treatments. The results are as follows ; 1) The style of spraying pesticides in the target area is mostly an individual one, not cooperative one. And the subjects of spraying are householders, whose educational backgrounds are beneath notice. More than 2~5 of the subjects are women or old men of 60 years old or so. These are seen to derive from the socio-economic status of Korean agricultural families; their younger generation's moving to greater cities and their petty farming styles. 2) As for the safety measures for the spraying of pesticides, those which have nothing to do with the economic, problems such as efficient spraying and productivity, are well obeyed. On the other hand, some safety measures as the use of safety devices, and spraying time, the degree of dilution of pesticides and the spraying method In windy days, are not obeyed very well, for to keep those makes spraying difficult to do and productivity worse. These facts indicate that the safety measures for using pesticides must be directly concerned with the spraying process, farming style and farmers' socio economic status, rather than the subject's knowledge or carefulness. 3) Even In cases of poisoning they do rarely consult the doctors. This is caused by the problem of their locality and transportation since one should pass away a day even in the busiest season to consult doctors, and by their low socio-economic status. 4) The epidemiological studies on pesticide poisonings should be necessarily led to a socio-medical one which are concerned together with the spraying process of pesticides, farming style, farmer's socio-economic status and discrepancies in public health policies between agricultural communities and urban ones.

• Biomedical Science Letters
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• v.28 no.2
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• pp.83-91
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• 2022

This study was performed to investigate the contamination status of microorganisms that cause food poisoning in shellfish distributed in the metropolitan area of South Korea. The analyses were conducted according to the sample type, season, and region. In particular, the genotype of food poisoning viruses that explosively cause collective food poisoning was analyzed. Total 483 each of four types of shellfish (Crassostrea gigas, Mytilus coruscus, Pectea albicans albicans, and Scapharca subcrenata) were collected from four distribution sites located in the metropolitan area. We investigated foodborne pathogen by multiplex PCR and RT/Nested PCR from shellfish. As a result, Vibrio parahaemolyticus and Bacillus cereus were detected in 13 and 21 samples and Norovirus (NoV) GI and GII were detected in 7 and 12 samples, respectively. V. parahaemolyticus and NoV GI and GII showed differences in types of shellfish and seasons, and no correlation was confirmed with regional differences. Also, as a result of genotyping for the detected NoV GI and GII, they were confirmed as NoV GI.7, GI.5 and GII.3, which are causes of collective food poisoning. Therefore, cross-infection with shellfish can cause food poisoning. In particular, attention must be paid to the handling and cooking of shellfish in organizations that implement group feeding, and it is necessary to establish a management system for microorganisms that cause food poisoning in the process of shellfish farming and distribution.

• Journal of Environmental Health Sciences
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• v.46 no.5
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• pp.565-575
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• 2020

Objective: South Korea still lacks systematic national poisoning data collection or a poison control center (PC). The objectives of this study are to provide estimates of poisoning incidents in South Korea and to stress the necessity of a national poisoning surveillance framework managed by a national PC. Method: The number of poisoning incidents was estimated based on the 2018 annual report of the American Association of Poison Control Centers' National Poison Data System (NPDS). Our estimation of poisoning data was classified according to age group, reason for poison exposure, and case management site. Results: Total poisoning cases estimated numbered 326,636, which is tantamount to 631 cases per 100 thousand. Poisoning cases among those younger than five years old accounted for 71.7% in the United States. Fatal poisoning cases were estimated to be 210.63 (95% CI: 199.70-222.15). Non-intentional poisoning cases (250,378 cases, 95% CI: 249,992-250,764, 76.7%) were estimated to be far higher than intentional cases (62,399 cases, 95% CI: 62,207-62,593, 19.1%). Conclusion: Our results can be used to suggest the necessity of producing national poisoning data and establishing a PC despite the uncertainty of estimation.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.4
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• pp.325-331
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• 2007

In this study, the inter-metal dielectric material of FSG was changed by low-k material in $0.13{\mu}m$ foundry-compatible technology (FCT) device process based on fluorinated silicate glass (FSG). Black diamond (BD) was used as a low-k material with a dielectric constant of 2.95 for optimization and yield-improvement of the low-k based device process. For yield-improvement in low-k based device process, some problems such as photoresist (PR) poisoning, damage of low-k in etch/ash/cleaning process, and chemical mechanical planarization (CMP) delamination must be solved. The PR poisoning was not observed in BD based device. The pressure in CMP process decreased to 2.8 psi to remove the CMP delamination for Cu-CMP and USG-CMP. $H_2O$ ashing process was selected instead of $O_2$ ashing process due to the lowest condition of low-k damage. NE14 cleaning after ashing process lot the removal of organic residues in vias and trenches was employed for wet process instead of dilute HF (DHF) process. The similar-state of SRAM yield was obtained in Cu/low-k process compared with the conventional $0.13{\mu}m$ FCT device by the optimization of these process conditions.

• Journal of Food Hygiene and Safety
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• v.23 no.2
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• pp.91-97
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• 2008

Kimchi is a representative traditional food in Korea and a type of vegetable product that is the unique complex lactic acid fermentation in the world. It can be considered as a unique fermented food generated by various flavors, which are not included in raw materials, that can be generated by mixing and fermenting various spices and seasonings, such as red pepper powder, garlic, ginger, and salted fish, added to Chinese cabbages. Functionalities in Kimchi have been approved through several studies and the probiotic function that is mainly based on lactic acid bacteria including their physical functions in its contents has also verified. Studies on the verification of the safety of Kimchi including its physiological functions have been conducted. In particular, the function of lactic acid bacteria, which is a caused of the fermentation of Kimchi. Although the lactic acid bacteria contributed to the fermentation of Kimchi is generated from raw and sub-materials, the lactic acid bacteria attached on Chinese cabbages has a major role in the process in which the fermentation temperature and dominant bacteria are also related to the process. The salt used in a salt pickling process inhibits the growth of the putrefactive and food poisoning bacteria included in the fermentation process of Kimchi and of other bacteria except for such lactic acid bacteria due to the lactic acid and several antimicrobial substances generated in the fermentation process, such as bacteriocin and hydrogen peroxide. In addition, the carbon dioxide gas caused by heterolactic acid bacteria contributes to the inhibition of aerobic bacteria. Furthermore, special ingredients included in sub-materials, such as garlic, ginger, and red pepper powder, contribute to the inhibition of putrefactive and food poisoning bacteria. The induction of the change in the intestinal bacteria as taking Kimchi have already verified. In conclusion, Kimchi has been approved as a safety food due to the fact that the inhibition of food poisoning bacteria occurs in the fermentation process of Kimchi and the extinction of such bacteria.

• Journal of KIISE
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• v.43 no.11
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• pp.1233-1244
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• 2016

In the IoT network environments for LLNs(Low power and Lossy networks), IPv6 Routing Protocol for Low Power and Lossy networks(RPL) has been proposed by IETF(Internet Engineering Task Force). The goal of RPL is to create a directed acyclic graph, without loops. As recommended by the IETF standard, RPL route recovery mechanisms in the event of a failure of a node should avoid loop, loop detection, DIO Poisoning. In this process, route recovery time and control message might be increased in the sub-tree because of the repeated route search. In this paper, we suggested RPL route recovery method to solve the routing overhead problem in the sub-tree during a loss of a link in the RPL routing protocol based on IoT wireless networks. The proposed method improved local repair process by utilizing a route that could not be selected as the preferred existing parents. This reduced the traffic control packet, especially in the disconnected node's sub tree. It also resulted in a quick recovery. Our simulation results showed that the proposed RPL local repair reduced the recovery time and the traffic of control packets of RPL. According to our experiment results, the proposed method improved the recovery performance of RPL.

• Journal of The Korean Society of Clinical Toxicology
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• v.18 no.1
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• pp.11-17
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• 2020

Purpose: This study examines errors in death certificates (DCs) issued to cases of poisoning. Methods: DCs issued in poisoning cases were retrospectively reviewed. Errors in the DC were classified as major and minor errors, and were evaluated in accordance with their impact on the process of selecting the cause of death (COD). Results: A total of 79 DCs were evaluated; 43 (54.4%) DCs were issued in the emergency department (ED), and 36 (45.6%) DCs were issued outside the ED. The average major and minor errors per DC were determined to be 0.4 and 3.3, respectively. Moreover, an average of 3.0 errors were discovered in DCs issued at the ED, and 4.4 errors in DCs issued outside the ED. The most common major errors were incorrect manner of death (11.4%, 9/79), followed by unacceptable COD (7.6%, 6/79), and the mode of dying as an underlying COD (5.1%, 4/79). The common minor errors most frequently encountered were incorrect time interval (86.1%, 68/79), followed by incorrect other significant conditions (73.4%, 58/79), and no record for date of onset (62.0%, 49/79). Conclusion: Our results indicate that the total numbers of major errors, minor errors and cases of misjudged cause of death were greater in DCs issued outside the ED than in DCs issued at the ED. The most frequently quoted major error of DCs related to poisoning was determined to be the incorrect manner of death.

• Safety and Health at Work
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• v.10 no.3
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• pp.265-274
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• 2019

Background: Methyl alcohol poisoning in mobile phone-manufacturing factories during 2015-2016 was caused by methyl alcohol use for cleaning in computerized numerical control (CNC) processes. To determine whether there were health complications in other workers involved in similar processes, the Occupational Safety and Health Research Institute conducted a survey. Methods: We established a national active surveillance system by collaborating with the Ministry of Employment and Labor and National Health Insurance Service. Employment and national health insurance data were used. Overall, 12,048 employees of major domestic mobile phone companies and CNC process dispatch workers were surveyed from 2016 to 2017. We investigated methyl alcohol poisoning by using the national health insurance data. Questionnaires were used to investigate diseases due to methyl alcohol poisoning. Results: Overall, 24.9% of dispatched workers were employed in at least five companies, and 23.9% of dispatched workers had missing employment insurance history data. The prevalence of blindness including visual impairment, optic neuritis, visual disturbances, and alcohol toxicity in the study participants was higher than that reported in the national health insurance database (0.02%, 0.07%, 0.23%, and 0.03% versus 0.01%, 0.07%, 0.13%, and 0.01%, respectively, in 2015). Moreover, 430 suspicious workers were identified; 415 of these provided an address and phone number, of whom 48 responded (response rate, 11.6%). Among the 48 workers, 10 had diseases at the time of the survey, of whom 3 workers were believed to have diseases related to methyl alcohol exposure. Conclusion: This study revealed that active surveillance data can be used to assess health problems related to methyl alcohol poisoning in CNC processes and dispatch workers.

• Journal of The Korean Society of Clinical Toxicology
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• v.16 no.2
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• pp.131-140
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• 2018

Purpose: The National Emergency Medical Center has been running a project for the storage and delivery of antidotes for acute poisoning patients of the Department of Health and Welfare, Korea. This study analyzed the results of this project over the past two years. Methods: The requests received by the National Emergency Medical Center and the data on the delivery process were analyzed. Results: This study analyzed a total of 121 patients with acute poisoning, who were requested to receive an antidote reserved at 20 key hospitals in 2015-2017, and whose age was $52.3{\pm}23.5\;years$; old; 54 were women. Intentional poisoning were 58.7%, and the home was the most common place of exposure (66.9%). The toxic substances were chemicals (32.2%), pesticides (27.3%), medicines (24.8%), and snake venom (4.1%). The patient's poison severity score was $2.4{\pm}0.7$ (median 3) indicating moderate-to-severe toxicity. Antidote administration was the cases treated in key hospitals 67.8% (82/121), in which transferred patients accounted for 57.3% (47/82). After receiving an antidote request from a hospital other than the key hospitals, the median was 75.5 minutes (range 10 to 242 minutes) until the antidote reached the patient, and an average of 81.5 minutes was required. The results of emergency care were intensive care unit (70.3%), general wards (13.2%), death (10.7%), and discharge from emergency department (5.0%). Conclusion: This study showed that the characteristics of acute poisoning patients treated with an antidote were different from previous reports of poisoned patients in the emergency department, and basic data on the time required for delivery from key hospitals was different.