• Title/Summary/Keyword: high safety

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Preparation of blocking ultraviolet mica composites using Nano-TiO2 (Nano-TiO2를 이용한 자외선차단 마이카 복합체 제조)

  • Yun, Ki Hoon;Lee, Jaebok;Moon, Young-Jin;Go, Hee Kyoung;Lee, Yi;Lee, Dong-Kyu
    • Journal of the Korean Applied Science and Technology
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    • v.35 no.4
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    • pp.1197-1205
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    • 2018
  • UV protection cosmetics belong to functional cosmetics and contain organic or inorganic UV blocking pigments. The inorganic UV blocking pigments are mainly zinc oxide and titanium dioxide. It is known that inorganic UV blocking pigment has a diameter of 60 to 100 nm and has good blocking ability of UVA and UVB. Also, it has high inactivity against sunlight including UV and is excellent in safety. In addition, it is not absorbed or accumulated on the skin like organic pigments and does not cause skin irritation or allergy. In this study, mica, a plate-shaped inorganic pigment, nanosized titanium dioxide, an UV blocking material, and hydrophobic silica were surface-treated with surfactants. And then, titanium dioxide nanoparticles and silica were physically adsorbed on the mica by non-chemical mutual attraction due to differences in charge. Thereafter, the mica complex was surface-treated with silane to prepare a hydrophobic UV blocking pigment complex. The plate-shaped UV blocking composite improves the cohesiveness of a general nanoparticle material titanium dioxide, enhances UV blocking effect due to uniform dispersion, and can greatly improve dispersion stability in cosmetic formulations by surface treatment with hydrophobic property. The surface charge of the pigment was evaluated by zeta potential. The properties of the UV blocking pigment complex were evaluated by FE-SEM, XRD, FT-IR and UV-VIS.

A Study on Measures for Strengthening Intelligence-Led Policing Using HUMINT (휴민트를 이용한 정보지향적 경찰활동 강화방안)

  • Shin, Jae-Hun;Kim, Sang-Woon
    • The Journal of the Korea Contents Association
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    • v.19 no.2
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    • pp.112-120
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    • 2019
  • This study conducts survey on currently working police officers to examine the actual utilization of HUMINT and suggest measures for strengthening the effective intelligence police activity, Intelligence Led Policing. For the completeness of study, this study presented evidences based on survey data from police officers at sites and this study also suggested improvement measures. in regulating the scope of duty, "Act on the Performance of Duties by Police Officers" regulates that 'Gathering, preparation, and distribution of public safety information' is the duty of police officer and defines the information gathering activity of police as the unique work of police officer. Thus, in accordance with "Act on the Performance of Duties by Police Officers", police officers gather various information to prevent crimes and maintain orders. Among the information gathering methods used by police officer, HUMINT is the oldest measure and it is still utilized. HUMINT has the advantages of low expense, high accuracy, and critical impact on the other. Nevertheless, due to limitations in data objectification, measurement, and responses to double attack, HUMINT is underappreciated. With awareness on such HUMINT issues, this study conducted survey on in-service police officers and examined the actual state of HUMINT. Based on the survey result, this study suggested Intelligence-Led Policing as the effective application method.

Derivation of Flood Hazard Curves for SOC Facilities under Local Intensive Precipitation (LIP(극한강우) 조건하에서 중요 SOC 시설물에 대한 재해도 곡선 작성)

  • Kim, Beom Jin;Han, Kun Yeun*
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.39 no.1
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    • pp.183-194
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    • 2019
  • In recent years, the risk of external flooding of major national facilities has increased significantly since 2000 due to the increase in local heavy rainfall events. For important domestic national facilities, it is necessary to analyze the risk of external flooding as flooding in major sites due to heavy rain can cause functional paralysis in major facilities and ultimately lead to massive trouble events. In order to manage the safety of main facilities and its related facilities at a high level, it is necessary to analyze the degree of disaster such as flood depth, flood flow rate, flood time and flood intensity when extreme floods (LIP) are introduced. In addition, the degree of vulnerability of these related facilities should be assessed and risk assessments should be reassessed through linkage analysis that combines the degree of disaster and vulnerability. By calculating a new flood hazard curve for the flood depth and flood intensity in major national facilities under the heavy rainfall conditions through this study, it is expected to be a basis for the waterproof design of important SOC facilities, flood prevention function design, advancement of flood prevention measures and procedures and evaluation of flood mitigation functions.

Increased Youth Single-person Households and Solitary Deaths realized by College Students (대학생이 인식한 청년 1인 가구 및 청년 고독사 증가 현상)

  • Park, Su-Sun
    • Journal of Digital Convergence
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    • v.16 no.12
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    • pp.635-640
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    • 2018
  • The study conducted a Focus Group Interview (FGI) on college students to identify single-person households and Solitary Deaths of single-person households recognized by college students. This can be provided as basic data to address problems in single-person households and social problems such as future youth solitary death and will contribute to building a social safety net. This study conducted FGI to analyze data for five fourth graders majoring in social welfare. In the case of involuntary independent living, the high poverty and unemployment rate of single-person households was cited as the cause of economic instability, housing problems and emotional relationship formation. He said that he thinks about young loneliness because he has vague fears about what happens in the media and what can happen to them. As the number of young single-person households will inevitably increase in the coming months and economic difficulties are the biggest problem and the biggest cause of young solitude, institutional support is needed first, especially for housing costs.

Ecological Risk Assessment for Cadmium in Environmental Media (환경매체별 카드뮴의 생태위해성평가)

  • Lee, Byeongwoo;Lee, Byoungcheun;Yoon, Hyojung;Park, Kyunghwa;Kim, Pilje
    • Journal of Environmental Health Sciences
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    • v.44 no.6
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    • pp.548-555
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    • 2018
  • Objectives: We conducted ecological risk assessment for cadmium, a heavy metal and carcinogen, to identify safety standards by environmental media and to determine its impact on ecosystems by estimating and evaluating exposure levels. Methods: Species sensitivity distributions (SSDs) were generated using ECOTOX DB. A hazardous concentration of 5% (HC5) protective of most species (95%) in the environment was estimated. Using this estimate, predicted no effect concentrations (PNECs) were calculated for aquatic organisms. Based on the calculated PNECs for aquatic organisms, PNEC values for soil and sediment were calculated using the partition coefficient. Predicted exposure concentrations (PECs) were also calculated from environmental monitoring data with hazard quotients (HQs) calculated using PNECs for environmental media. Results: Chronic toxicity data were categorized into four groups and 11 species. In species sensitivity distribution (SSD) analysis, HC5 was $0.340{\mu}g/L$. Based on this value, the PNEC value for aquatic organisms was calculated as $0.113{\mu}g/L$. PNEC values for soil and sediments using a partition coefficient were calculated as 15.02 mg/kg and 90.61 mg/kg, respectively. In an analysis of environmental monitoring data, PEC values were calculated as $0.017{\mu}g/L$ for water, 1.01 mg/kg for soil, and 0.521 mg/kg for sediment. Conclusions: HQs were 0.150, 0.067 and 0.006 for water, soil and sediment, respectively. HQs of secondary toxicity were 0.365 for birds and 0.024 for mammals. In principle, it is judged that an HQ above 1 indicates a high level of risk concern while an HQ less than 1 indicates an extremely low level of risk concern. Therefore, with HQs of cadmium in the environment being <1, its risk levels can be considered low for each media.

Mechanical Properties and Impact Resistance Review of Carbon Fiber Reinforced Cement Composites with Different Fiber Contents and Fiber Lengths (섬유혼입률 및 섬유길이 변화에 따른 탄소섬유 보강시멘트 복합재료의 역학적 특성과 내충격성 검토)

  • Heo, Gwang-Hee;Song, Ki-Chang;Park, Jong-Gun;Han, Yoon-Jung;Lim, Cae-Young
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.23 no.4
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    • pp.86-95
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    • 2019
  • Recently, the applications of carbon fiber have been broader than ever when it comes to such industrials as automobiles, ships, aerospace, civil engineering and architecture because of their lightweight-ness and high mechanical properties. This study analyzed mechanical properties and flexural behavior of carbon fiber reinforced cement composites(CFRC) with different fiber contents and fiber lengths, and also impact resistance by natural drop test on mortar specimens was compared and examined. In addition, contents of carbon fiber(CF) were varied by 0.5%, 1.0%, 2.0% and 3.0%. Fiber lengths was used for 6 mm and 12 mm, respectively. As a result of the test, the flow value was very disadvantageous in terms of fluidity due to the carbon fiber ball phenomenon, and the unit weight was slightly reduced. In particular, the compressive strength was decreased with increasing carbon fiber contents. On the other hand, the flexural strength was the highest with 12 mm fiber length and 2% fiber content. As the results of the impact resistance test, the specimens of plain mortar takes about 2~3 times to final fracture, while the specimens of CFRC is somewhat different depending on the increase of the fiber contents. However, when the fiber length is 12 mm and the fiber content is 2%, the impact resistance was the highest.

Seismic Fragility Analysis of Rahmen-type Continuous Bridge Supported by High Piers (고교각으로 지지된 라멘형 연속교의 지진취약도 분석)

  • Kang, Pan-Seung;Hong, Ki-Nam;Yeon, Yeong-Mo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.23 no.5
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    • pp.84-95
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    • 2019
  • This paper reports the process of seismic fragility analysis for the rahman-type continuous bridge system. The target structure was the five span highway bridge with maximum pier hight of 72m. OpenSees software was used for the nonlinear time history analysis. In this study, 50 ground motions are considered for nonlinear time history analysis. For each ground motion, PGA was scaled from 0.1g to 2.0g with intervals of 0.1g in order to consider a wide range of the seismic intensity measure. In addition, yield displacement and ultimate displacement of each pier were calculated through section analysis. Based on the result of non linear time history analysis and section analysis, damage condition of target bridge was classified according to the definition of damage condition proposed by Barbat et al. As a result, it was predicted that Extensive Damage occurred at P1 when 0.731 g earthquake occurred in the longitudinal direction. Based on the seismic fragility analysis results, it is found that the probability of occurrence of Extensive Damage in the 4,800 - year period earthquake was about 4.2%. Therefore the target bridge has enough safety for earthquake.

Feasibility Study of Phosphor Particle Blended Hybrid Dosimeter for Quality Assurance in Radiation Therapy (Phosphor Particle 혼합형 Hybrid 선량계의 방사선치료 Quality Assurance에 대한 적용가능성 평가)

  • Shin, Yohan;Han, Moojae;Jung, Jaehoon;Cho, Heunglae;Park, Sungkwang
    • Journal of the Korean Society of Radiology
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    • v.13 no.3
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    • pp.333-338
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    • 2019
  • In the field of radiotherapy, the Quality Assurance(QA) procedure to verify the safety of treatment is considered to be very important. However, due to various problems of the conventional dosimeters used for the QA, researches on these dosimeters have been actively carried out to replace them. In this study, to maximize the sensitivity by visible light(VL) emitted from phosphors, blended hybrid sensors were fabricated by blending various weight percent(wt%) of $Gd_2O_2S:Tb$ which is a phosphor with excellent fluorescence efficiency into $PbI_2$. Then, the electrical properties to high energy radiation from the blended sensors and the pure $PbI_2$ sensor were compared and evaluated. As a result of the sensitivity evaluation, the sensor of 3wt% showed the highest value with more than 40% difference from the other sensors, and gradual decreasing in sensitivity was observed with increasing wt% except for the sensor of 3wt%. Also, in the reproducibility evaluation, the pure $PbI_2$ sensor exhibited a large variation in coefficient of variation(CV)>0.015, while all the blended sensors showed CV<0.015.

Assessment of Damage for the Three­Storied Stone Pagoda of Bulguksa Temple in Gyeongju (경주 불국사 삼층석탑(석가탑)의 손상도 평가)

  • Lee, Gemma
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.9
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    • pp.299-305
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    • 2019
  • As the damage factors of the three­storey stone pagoda of the Bulguksa Temple in Gyeongju could cause a reduction in the historical and artistic value and accelerate the deterioration of the stone, an appropriate solution is needed. The aim of stone conservation is to conserve the original shape and convey originality from the ancestors to their descendants. This procedure includes a record of the condition, being available in the future. In particular, the damage assessment could be used in conservational research, educational data, conservational treatment, and preventive data. As a result of quantitative damage assessment, biological damage indicated 159 %, chemical damage 114 %, and physical damage 16 %. The west direction revealed 95 % because of the amount of sunshine, moisture, and expansion of rock. Complex factors and high range damage were observed on the foundation and body of the pagoda. Since the top of pagoda was restored in the 1970s, the state presented a good condition. By doing this, the number of organisms could be reduced by cleaning and the physical damage could be minimized by bonding. On the other hand, continuous monitoring will be needed because there is a possibility of reforming the damage in the future.

Anti-oxidative and anti-inflammatory effects of Danpitang in RAW 264.7 cell (단피탕(丹皮湯) 추출물의 항산화 및 항염증 효과 연구)

  • Oh, Sol-La;Park, Hye-Su;Kim, Ee-Hwa;Kim, Yong-Min
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.32 no.3
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    • pp.37-47
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    • 2019
  • Objectives : The purpose of this study is to investigate the anti-oxidative and the anti-inflammatory effects of Danpitang(DPT) extract in RAW 264.7 macrophages. Methods : The macrophage cell line RAW 264.7 cells were used and MTT assay was performed to measure the cell viabilities at the various concentrations of DPT($50-400{\mu}g/m{\ell}$). Nitric oxide(NO) was measured in LPS-induced RAW 264.7 cells. Expressions of iNOS, COX-2, $TNF-{\alpha}$, $IL-1{\alpha}$, $IL-1{\beta}$ and IL-6 were also performed by real-time PCR. Protein expression of iNOS and COX-2 was confirmed by western blot. The anti-oxidant activities of DPT was measured by DPPH radical scavenging activity. Results : 1. There was no cytotoxicity in RAW 264.7 cells treated with DPT compared to the control. 2. DPT treated group significantly inhibited NO production compared to the LPS treated group. 3. DPT treated group significantly decreased mRNA expressions of iNOS, COX-2, $TNF-{\alpha}$, $IL-1{\alpha}$, $IL-1{\beta}$ and IL-6 compared to the LPS treated group. 4. To evaluate the safety of the products for the human body, Adverse events, SCORAD Index Assessment were conducted; There were no severe adverse events during this study. And SCORAD Index showed a statistically significant decrease in treatment group in baseline, 2 weeks and 4 weeks. Therefore, it is suggested that products, if used for certain period, should be safe for the human body. 5. DPT was found to have high DPPH free radical scavenging ability. Conclusions : According to the above results, DPT can be used as a therapy in various anti-inflammatory skin diseases.