• 제목/요약/키워드: Barrier protection

검색결과 213건 처리시간 0.022초

후처리 적용에 따른 방식용 Al-3%Mg 용사코팅 층의 해수 내 전기화학적 특성 (Electrochemical Characteristics in Sea Water of Al-3%Mg Arc Spray Coating Layer for Corrosion Protection with Sealing Treatment)

  • 박일초;김성종
    • 한국통신학회논문지
    • /
    • 제40권5호
    • /
    • pp.974-980
    • /
    • 2015
  • 해양환경 하에서 강재에 대한 방식 목적으로 Al-3%Mg 용사선재를 이용하여 아크 용사코팅을 실시하였다. 그리고 Al-3%Mg 용사코팅 층의 내식성을 개선하기 위하여 유/무기 복합 세라믹 후처리를 실시하였다. 후처리 적용에 따른 용사코팅 층의 다양한 전기화학적 실험 결과, 양극분극과 음극분극 실험 시 모든 전위구간에서 후처리 적용 시 전류밀도가 작게 나타나 내식성 개선이 확인되었다. 그리고 후처리된 용사코팅 층의 표면에서 관찰된 마이크로 크랙의 영향으로 자연전위 계측 시 심한 전위변동이 나타났으며, 양극분극 실험 시에는 후처리 층의 탈리손상이 용이하게 발생하였다. 그럼에도 불구하고 타펠분석을 기반으로 외부 환경차단 효과를 나타내는 코팅 효율이 92.11%로 산출되어 Al-3%Mg 용사코팅 층의 내식성이 향상되었다.

고 강도 차폐벽돌을 이용한 방사선치료실의 차폐설계 (Design for Radiotherapy Room with High Density Shielding Block)

  • 서창옥;김귀언;추성실
    • 한국의학물리학회지:의학물리
    • /
    • 제15권4호
    • /
    • pp.247-254
    • /
    • 2004
  • 신체 심부의 악성종양치료를 위한 6~15 MV의 강력한 에너지의 방사선과 종양만을 조사하기 위한 입체조형치료, 세기 조절방사선치료, 입체적 치료방법 등이 개발됨으로써 방사선의 사출구가 전체 공간으로 확대되고 출력선량도 환자당 5~10 Gy의 과다 선량을 방출하기 때문에 고밀도의 차폐벽이 요구된다. 저자들은 세기조절방사선치료(IMRT)용 고 에너지 선형가속기를 기존건물에 설치하기 위하여 일반 콘크리트와 철, 티타늄등 중금속을 혼합한 고 밀도 차폐벽돌을 제작하여 방어벽을 설계하고 건축된 차폐벽으로부터 투과 산란된 선량을 측정하여 상호 비교하였다. 고 밀도 차폐벽돌을 사용함으로서 기존의 콘크리트(3.5 g/cc)에 비하여 고 에너지의 차폐율 즉 반가층 두께를 약 1/2로 줄일 수 있었다.

  • PDF

DIAPERS AND INFANT SKIN HEALTH

  • Song Ji Ho;Kim Sang Tae
    • Child Health Nursing Research
    • /
    • 제5권3호
    • /
    • pp.241-249
    • /
    • 1999
  • Diaper dermatitis, or commonly called 'diaper rash', is among the most prevalent cutaneous disorders of infancy and early childhood and important issue in nursing. The term itself is not diagnostic since it encompasses a variety of acute inflammatory reactions which are best regarded as a family of disorders arising from a combination of factors specifically attributable to the use of diapers Intensive study of the rash Process has shown that skin wetness and fecal enzyme activity are damaging to skin and lead to the development of diaper rash. This suggests that it is important to keep urine away from babies' skin, so that the skin remains as dry as Possible and maintains its barrier function abilities. Controlling the urine will also minimize the mixing of urine and feces within the diaper. which helps prevent the increased activity of enzymes that attack the skin and cause irritation. Therefore, a diaper that keeps the skin drier and limits the mixing of urine and feces will help Prevent the conditions that lead to diaper rash. Since their introduction about 35 years ago, disposable baby diapers have undergone many design and performance changes. In Particular. the Performance of diapers was advanced by the introduction of absorbent gel materials (AGMs) to Provide advantages in skin care. dryness, and leakage Protection Especially, important was the introduction of AGM which increased the absorbent capacity of the diaper several fold and Yielded marked reductions in the degree of skin hydration occurring under the diaper Studies show not only drier skin but more stable skin pH and less dermatitis with AGM diapers than with home-laundered cloth diapers or single-use diapers without AGM Minimizing diaper area skin wetness is important for managing and Preventing diaper rash. To minimize wetness, parents should use super absorbent diapers.

  • PDF

이층유체에서 부분 장벽에 의한 표면파와 내부파의 분산 (Surface and Internal Waves Scattering by Partial Barriers in a Two-Layer Fluid)

  • 슈레쉬 쿠마;오영민;조원철
    • 한국해안·해양공학회논문집
    • /
    • 제20권1호
    • /
    • pp.25-33
    • /
    • 2008
  • 파랑은 주로 바람에 의해서 발생하여 많은 에너지를 해안으로 전달하며 각종 수리현상을 야기하고 물질의 이송 등에 의하여 연안환경 뿐만 아니라 인간의 활동에도 큰 영향을 미친다. 또한, 해안 구조물과 파랑의 상호작용에 의한 효과를 정확히 예측하는 것은 구조물의 설계 및 거동특성 파악에 매우 중요하다. 본 논문에서는 이층 유체에서 수표면과 저층에 설치되어 있는 얇은 연직벽에 의한 표면파와 내부파의 분산을 선형파 이론을 이용하여 이차원으로 해석하였다. 반사계수를 계산하여 여러 경우에 대하여 효과를 분석한 결과 반사계수는 구조물의 형상과는 별도로 경계층의 위치와 유체간의 밀도차에 크게 영향을 받는 것으로 밝혀졌다.

ALD-Al2O3 보호층이 적용된 CrAlSiN 코팅막의 내부식성 특성에 관한 연구 (Effect of ALD-Al2O3 Passivation Layer on the Corrosion Properties of CrAlSiN Coatings)

  • 만지흠;이우재;장경수;최현진;권세훈
    • 한국표면공학회지
    • /
    • 제50권5호
    • /
    • pp.339-344
    • /
    • 2017
  • Highly corrosion resistance performance of CrAlSiN coatings were obtained by applying ultrathin $Al_2O_3$ thin films using atomic layer deposition (ALD) method. CrAlSiN coatings were prepared on Cr adhesion layer/SUS304 substrates by a hybrid coating system of arc ion plating and high power impulse magnetron sputtering (HiPIMS) method. And, ultrathin $Al_2O_3$ passivation layer was deposited on the CrAlSiN/Cr adhesion layer/SUS304 sample to protect CrAlSiN coatings by encapsulating the whole surface defects of coating using ALD. Here, the high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and energy dispersive X-ray spectrometry (EDX) analysis revealed that the ALD $Al_2O_3$ thin films uniformly covered the inner and outer surface of CrAlSiN coatings. Also, the potentiodynamic and potentiostatic polarization test revealed that the corrosion protection properties of CrAlSiN coatings/Cr/SUS304 sample was greatly improved by ALD encapsulation with 50 nm-thick $Al_2O_3$ thin films, which implies that ALD-$Al_2O_3$ passivation layer can be used as an effect barrier layer of corrosion.

염증성 장 질환 동물 모델에서 황금탕과 감초사심탕의 효능 연구 (A Study of the Effectiveness of Hwanggeum-tang and Gamchosasim-tang in the Mice Model of Inflammatory Bowel Disease)

  • 김영광;문영호
    • 대한한방내과학회지
    • /
    • 제42권3호
    • /
    • pp.351-374
    • /
    • 2021
  • Objectives: This study investigates the mechanism of Hwanggeum-tang (HGT) and Gamchosasim-tang (GST) on inflammatory bowel disease (IBD). Methods: The mice (C57BL/6N) were treated with distilled water and 3% dextran sulfate sodium (DSS) to experimentally induce ulcerative colitis. The mice were divided into 7 groups of (6 mice: normal, negative control, positive control (with sulfasalazine), 4 experimental groups (with HGT and GST, respectively). RAW 264.7 cells were used for cell experiments. The experiment was conducted in two ways: in vitro and in vivo. Results: In the experimental group (HGT, GST) of in vitro experiments, NO production decreased, and significant changes in gene expression and protein activation were observed. The length of the colon recovered in the experimental groups (HGT, GST) of the in vivo experiment was longer than that of the negative control group, and the mucosal barrier was recovered. Sone significant changes in the amount of mRNA expression were partially observed, and significant changes in protein activation also were confirmed. Conclusions: HGT and GST are effective in treating IBD caused by DSS. In the same herbal preparation group, the higher the concentration, the better the experimental effect, and when the same concentration was tested, HGT was more effective than GST. Herbal medicine has a higher antioxidant effect than sulfasalazine, so it is also excellent for cell protection.

A Study on the Effects That SMEs' Response to Non-Tariff Barriers Exerts on Export Performance: Focusing on Technical Barriers to Trade

  • Joo, Se-Hwan;Lee, Jae-Sung
    • Journal of Korea Trade
    • /
    • 제25권6호
    • /
    • pp.105-125
    • /
    • 2021
  • Purpose - This study analyzes the effects that the response to the technical barriers to trade (TBT), which are used by various countries as means to restrict imports, exerts on exports at a time when protectionism is emerging in the face of a global economic downturn. TBT has been widely used in developed countries for the safety and protection of their people. Recently, the use of TBT as a tool of protectionism has increased considerably in developing countries as well. Therefore, this study analyzes the South Korean SMEs' response and export performance. Design/methodology - To analyze SMEs' response to TBT and their export performance, this study conducted empirical analysis through statistical analysis. To this end, the research established a theory based on previous research and designed its hypothesis and research model. To verify the hypothesis and research model, factor analysis addressing validity and reliability was performed using SPSS 25 and AMOS 26, and the structural equation model was analyzed. Findings - This study found the causal relationship between the independent variable, the mediating variable, and the dependent variable adopted against the theoretical background to have little or no effect, in contrast with previous studies. In a break from previous studies, all hypotheses were rejected for innovation strategic competencies, one of the sub-factors of the independent variable, which is believed to be a result of the lack of practical research related to TBT. Originality/value - Previous studies performed analysis using trade statistics or macro data. A number of such studies analyzed the relationship between technical regulation and trade volume. This study differs from previous studies in some respects, because it analyzed the export performance of companies by establishing a hypothesis and implementing a research model with the factors analyzed in previous studies. In addition, a new attempt has been made by classifying the TBT response factors into technology competencies, human resource competencies, and innovation strategic competencies, and utilizing technology innovation and the export support system as mediating effects.

정신건강의학과 급성기 병동 공간계획을 위한 국외 가이드라인에 관한 연구 (A Study on the Ward Design Guideline Abroad for Architectural Planning of Acute Psychiatric Ward)

  • 지수인;박경현;채철균
    • 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
    • /
    • 제29권1호
    • /
    • pp.53-62
    • /
    • 2023
  • Purpose: Recently, the number of severely mentally ill patients has been increasing rapidly in Korea, but there are no design guidelines for spatial planning of Korea's acute psychiatric wards. The study aims to clarify the areas and required rooms in Korea's acute psychiatric wards which are important in establishing the design guidelines for Korea's acute psychiatric wards. Methods: This study proposed a structural framework based on the results of investigating and analyzing the acute psychiatric ward guidelines in the UK, Australia, and the U.S. and the areas and the required rooms of the wards stipulated in the basic data for establishing acute psychiatric ward design guidelines in Korea. The design guidelines for overseas acute psychiatric wards are 'Adult Acute Mental Health' in the UK, 'Adult Acute Mental Health Inpatient Unit' in the Australia, and 'Specific Requirements for Mental Health Hospitals' in the United States. Results: As a result of investigating and analyzing the design guidelines for overseas acute psychiatric wards, the areas of wards applicable to acute wards in domestic psychiatric wards were access, patient, treatment, support, and employee areas. In addition, the required rooms for each area were defined around major considerations such as visibility, convenience, comfort, security, safety, patient observation, barrier-free design, and privacy protection. Implications: The results of the study will be presented as a structural framework and basic data for establishing design guidelines for Korea's acute psychiatric wards, which is still absent.

Effects of natural mono- and di-saccharide as alternative sweeteners on inflammatory bowel disease: a narrative review

  • Eunju Kim
    • 대한지역사회영양학회지
    • /
    • 제28권3호
    • /
    • pp.181-191
    • /
    • 2023
  • Objectives: The incidence of inflammatory bowel disease (IBD) is increasing globally, and excessive added sugar consumption has been identified as one of the contributing factors. In the context of IBD, it is essential to explore functional sweeteners that can improve metabolic health and minimize the risk of IBD-related symptoms. This review article aims to shed light on the effects of natural mono- and di-saccharides as alternative sweeteners, specifically focusing on potential benefits for IBD. Methods: A comprehensive literature review was performed using PubMed and Google Scholar databases with articles published after the year 2000. The search terms 'IBD', 'added sugar', 'sweeteners', 'mono-saccharide', and 'di-saccharide' were combined to retrieve relevant articles. A total of 21 manuscripts, aligning with the objectives of the study, were selected. Papers focusing on artificial or high-intensity sweeteners were excluded to ensure relevant literature selection. Results: Multiple studies have emphasized the association between the high consumption of added sugars such as simple sugars and the increased risk of developing IBD. This is suggested to be attributed to the induction of pro-inflammatory cytokine productions and dysbiosis of the gut microbiota. Consequently, there is a growing demand for safe and functional sweeteners, in particular mono- and di-saccharides, that can serve as alternatives for IBD patients. Those functional sweeteners regulate inflammation, oxidative stress, and Intestinal barrier protection, and restore microbiome profiles in various IBD models including cells, animals, and humans. Conclusions: Understanding these mechanisms resolves the link between how sugar consumption and IBD, and highlights the beneficial effects of natural alternative sweeteners on IBD when they were administered by itself or as a replacement for simple sugar. Further, exploration of this relationship leads us to recognize the necessity of natural alternative sweeteners in dietary planning. This knowledge could potentially lead to more effective dietary strategies for individuals with IBD.

Preliminary study for the development of radiation safety evaluation methodology for industrial kV-rated radiation generator facilities

  • Hye Sung Park ;Na Hye Kwon ;Sang Rok Kim ;Hwidong Yoo;Jin Sung Kim ;Sang Hyoun Choi;Dong Wook Kim
    • Nuclear Engineering and Technology
    • /
    • 제55권10호
    • /
    • pp.3854-3859
    • /
    • 2023
  • Background: This study aims to develop an evaluator that can quickly and accurately evaluate the shielding of low-energy industrial radiation generators. Methods: We used PyQt to develop a graphical user interface (GUI)-based program and employed the calculation methodology reported in the National Council on Radiation Protection and Measurements (NCRP)-49 for shielding calculations. We gathered the necessary factors for shielding evaluation using two libraries designed for Python, pandas and NumPy, and processed them into a database. We verified the effectiveness of the proposed program by comparing the results with those from safety reports of six domestic facilities. Results: After verifying the effectiveness of the program using the NCRP-49 example, we obtained an average error rate of 1.73%. When comparing the facility safety report and results obtained using the program, we found that the error rate was between 1.09% and 6.51%. However, facilities that did not use a defined shielding methodology were underestimated by 31.82% compared with the program (the final barrier thickness satisfied the shielding standard). Conclusion: The developed program provides a fast and accurate shielding evaluation that can assist personnel that work in radiation generator facilities and government officials in reviewing safety.