• 제목/요약/키워드: harmful material

검색결과 341건 처리시간 0.023초

An Interpretation of the Gaps between 'Fact' and 'Oral Materials' in Political Elite Oral History ('사실'과 '구술자료'의 간극에 대한 하나의 해석 정치엘리트 구술연구를 중심으로)

  • Jo, Young-Jae
    • The Korean Journal of Archival Studies
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    • 제43호
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    • pp.43-70
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    • 2015
  • The value and validity of elite oral materials have been questioned because of their gaps with 'fact'. The purpose of this article is to analyze these gaps and to propose some solutions that can reduce the gaps. According to the analysis of this article, there are three types of the gaps that qualitatively differ from each other. The first type of the gaps is produced in the process of generation of memory. This type is made because informants cognize and memorize the facts that exist outside themselves. Selective cognition, selective memory and individual experience come under this category. The second type is produced in the process of preserving the memory. Forgetting and memory transformation are main examples of this type. The third type is produced in the process of the interviews with the informants. False statements or lies fall into this category. The main conclusions are as follows. 1) all gaps in oral materials are not necessarily negative. It is because Some of these gaps- the first and the second type- are not only parts of the real world but also very useful for interpreting the world. 2) The third type of the gaps are very harmful and it is need to be eradicated or reduced. For this, this article proposes some solutions.

A Criticism about Neo-Confucianism and progressive Thought of Fu-Shan(傅山) (부산(傅山)의 리학(理學)비판과 개혁사상)

  • Hwang, Byong Kee
    • (The)Study of the Eastern Classic
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    • 제37호
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    • pp.411-439
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    • 2009
  • Fu-Shan(傅山, 1607~1684) was a progressive actualist between the late Ming(明) dynasty and the early Qing(淸) dynasty. He regards the intellectuals at that time as scarecrows leaned on the empty and exaggerative moral philosophy which the neo-confucian of Song(宋) dynasty established. He thinks that the neo-confucian discussion cause harmful side effects, disregarding the utility side and the variety of the actual world. His thought becomes known all in political thought and literature. He asserts that the neo-confucian ideas provides the logical frame which regulates the actual world and creates a kind of absolute moral ideology. Therefore he insists that the Saint in the true sense of the word consequently is the social reformer and revolutionist who exposes the irrational elements of society. He insists that literature also must be able to express vividness of the actual world. He thinks that genuine literature must have creative contents and find one's own free wild way. He asserts that old literary style from the mimicry is the act which goes against human natural. He thinks that the writing must be able to express the actual world.

Characteristics of fruiting body growth according to alternative substrates of king oyster mushroom (Pleurotus eryngii) (큰느타리 대체배지 종류에 따른 자실체 생육 특성)

  • Hye-Sung, Park;Gyong-Jin, Min;Eun-Ji, Lee;Tai Moon, Ha
    • Journal of Mushroom
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    • 제20권4호
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    • pp.274-278
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    • 2022
  • The present study aimed at selecting a cost-effective substrate for king oyster mushroom based on the growth characteristics of fruiting body for use as a basic resource to ensure stable production on farms. Compositional analysis of substrates manufactured with different materials in each process revealed that the total carbon content was 42.24-48.22% higher and the total nitrogen content was 1.7-2.29% higher in the processed lot than in the control (i.e., substrate used by the farmhouse; 40.86% and 1.39%, respectively). Meanwhile, the carbon-to-nitrogen ratio was the highest in the control (27.9% vs. 19.12-27.88% in the processed lot). When cultured for 28 days, the mycelium growth was 11.5 and 11.3 mm in substrates 1 and 6, respectively, indicating the fastest growth; meanwhile, the values were 10.1-10.3 mm in the control and substrate 11, showing a similar tendency. Mycelial density did not differ significantly among the processed lots. Yield per bottle was higher in substrates 8 (205.95 g/bottle), 7 (178.51 g/bottle), and 11 (170.63 g/bottle) than in the control (152.2 g/bottle). Fruiting body quality was comparable to controls in all processed lots. Overall, economic effects, such as substrate material prices, should be analyzed, and stability evaluations, such as residual pesticide and harmful microorganisms, should be undertaken along with further detailed examination to ensure safe and stable production on farms.

Removal of Harmful Impurities Including Microplastics in Sun-Dried Sea Salt by Membrane Technology (분리막을 이용한 천일염내 불순물 및 미세플라스틱 제거에 관한 연구)

  • Lim, Si-Woo;Seo, Chae-Hee;Hong, Seung-Kwan;Kim, Jeong-Hoon
    • Membrane Journal
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    • 제32권5호
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    • pp.314-324
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    • 2022
  • This study is aimed to design a membrane process that systematically removes contaminants including microplastics in sun-dried salt using a separation membrane. In this study, we selected the separation membrane material, pore size, and module suitable for the sun-dried salt fields, and proceeded with the experiments under the salt fields and laboratory conditions. A pilot plant was constructed and tested in our lab and in the actual saltern with the selected 200 kDa, 4 kDa ultrafiltration membranes, and 3 kDa nanofiltration membranes. Most of the impurities in the sea salt were 0.1 ㎛ in size, and more than 7 types of various microplastics were detected in the impurities. After that, as a result of checking the filtered water through the separation membrane process, no impurities were detected. As a result of comparing the existing sea salt component and the sea salt component prepared with separation membrane filtrate, impurities were effectively removed without change in the sea salt component.

Prototype Fabrication and Performance Evaluation of Metal-oxide Nanoparticle Sensor for Detecting of Hazardous and Noxious Substances Diluted in Sea Water (해수 중 유해위험물질 검출을 위한 금속산화물 나노 입자 센서의 시작품 제작 및 성능 평가)

  • Sangsu An;Changhan Lee;Jaeha Noh;Youngji Cho;Jiho Chang;Sangtae Lee;Yongmyung Kim;Moonjin Lee
    • Journal of the Korean Society of Marine Environment & Safety
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    • 제28권spc호
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    • pp.23-29
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    • 2022
  • To detect harmful chemical substances in seawater, we fabricated a prototype sensor and evaluated its performance. The prototype sensor consisted of a detector, housing, and driving circuit. We built the detector by printing an Indium-Tin-Oxide (ITO) nanoparticle film on a flexible substrate, and it had two detection parts for simultaneous detection of temperature and HNS concentration. The housing connected the detector and the driving circuit and was made of Teflon material to prevent chemical reactions that may affect sensor performance. The driving circuit supplied electric power, and display measured data using a bridge circuit and an Arduino board. We evaluated the sensor performances such as response (ΔR), the limit of detection (LOD), response time, and errors to confirm the specification.

It Was Possible to Reduce the Pain of the Victims of Humidifier Disinfectant (가습기살균제 피해자의 아픔을 줄일 수 있었다)

  • Kim, Pangyi;Choi, Yoon-Hyeong;Park, YeongChul;Park, Tae-Hyun;Leem, JongHan
    • Journal of Environmental Health Sciences
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    • 제48권1호
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    • pp.1-8
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    • 2022
  • Objectives: The purpose of this study is to reveal the circumstances under which the cases of harm to health caused by humidifier disinfectant were neglected and show the points where the number of victims and the degree of damage could have been reduced. In addition, it attempts to describe how damage management proceeded immediately after the incident and actually exacerbated the damage. Finally, it explores the unfortunate aspects of the recent trial. By doing so, it attempts to take this as an opportunity to consider whether a tragic event such as the humidifier disinfectant incident could occur in the future. Methods: This study collected and analyzed data on chemical material characteristics related to humidifier disinfectants, data on health effect characteristics, data on related laws and regulations from the Ministry of Environment, data related to the damage investigation by the Korea Environmental Industry and Technology Institute, and current contents. Results: The lack of related systems and laws is the area where the greatest responsibility for the cause of the humidifier disinfectant disaster falls, so it is difficult for the government to escape this responsibility. Establishing a dedicated department to identify the prevalence of certain diseases within the functions of the Health Insurance Review and Assessment Service to monitor health can greatly contribute to the prevention and management of diseases through early detection and management of group outbreaks caused by harmful factors. Humidifier disinfectant damage relief should have been expanded earlier beyond HDLI (humidifier disinfectant lung injury) to include non-specific diseases such as asthma, pneumonia, and interstitial pneumonia. The scope of relief benefits should have also been expanded earlier to include the payment of disability benefits. Fortunately, with the 2020 revision of the Special Act, the conditions for estimating causal relations were eased and individual screening systems such as health impact assessment were reorganized along with the introduction of a rapid screening system. Conclusions: The management system for chemical substances in a country is clearly of paramount importance, and the ministry in charge must have a response system in case of damage to health effects. Administration that looks at the victims' situation from their point of view is needed, and technical countermeasures are required to quickly recognize the prevalence of certain diseases.

Development of harmful algae collecting system for agricultural material recycling (농업재료 자원화를 위한 유해조류 포집 시스템 개발)

  • Kim, J.H.;Kim, J.M.;Jeong, Y. W.;Kwack, Y.K.;Sim, S.K.
    • Proceedings of the Korea Water Resources Association Conference
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    • 한국수자원학회 2022년도 학술발표회
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    • pp.50-50
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    • 2022
  • 한국농어촌공사 산하의 농업용저수지 중 3786개소에 대한 수질조사를 '19년도에 실시한 결과, TOC 기준 4등급 초과 저수지 비율은 약 20%로써, 도심 근교 저수지에서 녹조현상 빈발로 인해 수질, 악취, 미관 등의 환경문제 개선 민원이 다수 발생하고 있다. 현재 녹조 발생 사후관리를 위해 주로 사용되고 있는 대형 조류제거선은 저수심 수변부에서의 적용성에 한계가 있고, Al 기반의 응집제를 사용하여 조류를 수거해서 폐기하고 있는 실정이다. (주)이엔이티는 농어촌연구원, (주)코레드, (주)삼호인넷과 함께 호소나 정체하천의 수변지역에 적용될 수 있는 저에너지형 유해조류 포집시스템 개발과, 수거된 조류부산물을 무독화하여 농업재료로 재활용하는 방안을 연구하고 있다. 저수지나 정체수역의 녹조는 바람, 수면유동 등에 의해 수변에 집적되는 특성이 있어, 인공지능 기술로 녹조현상을 감시하여 조류 밀집구간에 접근할 수 있는 자율이동식 수상이동장치를 개발 중이다. 수상이동장치는 조류포집장치를 탑재하기 위한 부력체, 원격 운전이 가능한 무인항법장치, 수변식생대 및 저수심지역 이동을 고려한 수차방식 추진체, 전체 장치의 전원 공급을 위한 고성능 배터리 등으로 구성하여 상세 도면 설계를 진행하고 있다. 조류포집장치에는 표층에 주로 분포하는 남조류를 선택 흡입하는 포집 부표를 적용하였고, Al계 응집제 사용을 배제한 분리막 실험을 통해 침지형 막분리조 및 가압형 농축조를 설계하였다. 유해조류 포집 및 농축은 수상에서 이동체에 탑재하여 이뤄지고, 육상에서는 자원 회수가 가능하도록 회분식 응집공정으로 구분하였다. 조류 밀집지역에서 수거된 조류의 무독화 및 농업재료 자원화 타당성 평가를 위해 특용 버섯균주를 활용한 시료별 분석항목을 선정하고 실험 매트릭스에 따라 실증실험을 수행하였다. 수거조류를 전처리하여 성분 및 발열량을 분석하고 버섯재배 전후의 마이크로시스틴 독소(LR, RR, LR)를 포함한 성분 분석을 수행하여, 고체연료, 비료 및 사료로 활용방안을 검토하였다. 무인자율이동 조류포집장치는 실증화 규모로 제작하여 기선정된 테스트베드에서 현장적용성 평가를 수행할 예정이다. 본 연구를 통해 개발된 유해조류 포집 시스템은 기존의 녹조제거 방안을 보완하여 정체수역의 생태계 복원 및 친수공간의 환경개선 등에 적용되며, 무독화가 입증된 유해조류의 농업재료 자원화 기술은 고부가 상품 개발 및 환경폐기물 감축에 활용될 것이다.

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The effects of the Reynoutria japonica on skin-barrier and moisturizing in HaCaT cells (인간유래각질형성세포에서 호장근 추출물이 피부장벽 보호능과 보습능에 미치는 영향)

  • Eun Jeong Kang;Jia Bak;Yun-Sik Choi
    • Journal of the Korean Applied Science and Technology
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    • 제40권5호
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    • pp.965-976
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    • 2023
  • Reynoutria japonica is a perennate plant belonging to Polygonaceae and grows wild in East Asia containing Korea. Roots of Reynoutria japonica (R. japonica), part of roots of Reynoutria japonica, has been used for anti-inflammation and antispasmodics and contains emodin as active compound. Epidermis of skin is crucial roles to defense our body against stimulants, harmful substance and prevent water loss. In this study, we examined the effect of R. japonica and emodin, its active compound, on skin-barrier and moisturizing on HaCaT cells. First, antioxidant effect of R. japonica was prominent by scavenging ABTS+ radicals. Next, we conducted real time PCR and expression of filaggrin mRNA which is crucial role in differentiation of keratinocyte increased by R. japonica and emodin dose-dependently. In addition, R. japonica and emodin significantly elevated the expression of HAS-2 mRNA which play a role in hyaluronic acid synthesis on HaCaT cells. Taken together, R. japonica containing emodin, as active compound has potential as a cosmetic material for enhancing the function of skin-barrier and moisturizing in epidermis.

Evaluation of applicability of xanthan gum as eco-friendly additive for EPB shield TBM soil conditioning (친환경 첨가제로서 잔탄검의 토압식 쉴드 TBM 쏘일 컨디셔닝 적용성 평가)

  • Suhyeong Lee;Hangseok Choi;Kibeom Kwon;Byeonghyun Hwang
    • Journal of Korean Tunnelling and Underground Space Association
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    • 제26권3호
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    • pp.209-222
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    • 2024
  • The Earth Pressure Balance (EPB) shield Tunnel Boring Machine (TBM) is widely used for underground tunnel construction for its advantages, such as eliminating the need for additional facilities compared to the slurry shield TBM, which requires Slurry Treatment Plant (STP). During EPB shield TBM excavation, a soil conditioning technique is employed to enhance the physical properties of the excavated soil by injecting additives, thus broadening the range of applicable ground conditions to EPB shield TBMs. This study explored the use of xanthan gum, a type of biopolymer, as an alternative to the commonly used polymer additive. Biopolymers, derived from biological sources, are fully biodegradable. In contrast to traditional polymers such as polyacrylic acid, which contain environmentally harmful components, xanthan gum is gaining attention as an eco-friendly material due to its minimal toxicity and environmental impact. Test conditions with similar workability were established through slump tests, and the rheological characteristics were assessed using a laboratory pressurized vane shear test apparatus. The experiments demonstrated that, despite exhibiting similar workability, the peak strength in the flow curve decreased with increasing the content of xanthan gum. Consequently, a correlation between the xanthan gum content and peak strength was established. Replacing the traditional polymers with xanthan gum could enable stable EPB shield TBM operation by reducing equipment load, in addition to offering environmental benefits.

Evaluation of the Usefulness of the Transmittance of Metal Filaments Fabricated by 3D Printers in Radiation Therapy (방사선 치료에서 3D 프린터로 제작된 금속 필라멘트의 투과율에 관한 유용성 평가)

  • Kwon, Kyung-Tae;Jang, Hui-Min;Yoon, Myeong-Seong
    • Journal of the Korean Society of Radiology
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    • 제15권7호
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    • pp.965-973
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    • 2021
  • Since radiation therapy is irradiated with high-energy X-rays in a variety of at least 20 Gy to 80 Gy, a high dose is administered to the local area where the tumor is located, and various side effects of some normal tissues are expected. Currently, in clinical practice, lead, a representative material, is used as an effort to shield normal tissues, but lead is classified as a heavy metal harmful to the human body, and a large amount of skin contact can cause poisoning. Therefore, this study intends to manufacture a measurement sheet that can compensate for the limitations of lead using the materials Tungsten, Brass, and Copper of the 3D printer of the FDM (Fused Deposition Modeling) method and to investigate the penetration performance. Tungsten mixed filament transmission measurement sheet size was 70 × 70 mm and thickness 1, 2, 4 mm using a 3D printer, and a linear accelerator (TrueBeam STx, S/N: 1187) was measured by irradiating 100 MU at SSD 100 cm and 5 cm in water using a water phantom, an ion chamber (FC-65G), and an elcetrometer (PTW UNIDOSE), and the permeability was evaluated. As a result of increasing the measurement sheet of each material by 1 mm, in the case of Tungsten sheet at 3.8 to 3.9 cm in 6 MV, the thickness of the lead shielding body was thinner than 6.5 cm, and in case of Tungsten sheet at 4.5 to 4.6 cm in 15 MV. The sheet was thinner than the existing lead shielding body thickness of 7 cm, and equivalent performance was confirmed. Through this study, the transmittance measurement sheet produced using Tungsten alloy filaments confirmed the possibility of transmission shielding in the high energy region. It has been confirmed that the usability as a substitute is also excellent. It is thought that it can be provided as basic data for the production of shielding agents with 3D printing technology in the future.