• Journal of Korean Library and Information Science Society
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• v.50 no.4
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• pp.635-658
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• 2019

In this study, the harmful factors measured in S university's central library were divided into ① air harmful substance ② biological harmful factors ③ carbon monoxide, carbon dioxide, and nitrogen dioxide concentration, measured and analyzed compared to the relevant criteria. The analysis showed that the harmful substances in the air - fine dust, asbestos, volatile organic compounds and formaldehyde - were all lower than the relevant standards, and that biological harmful factors such as fungi in the air, gramophageal bacteria, and endotoxin were also found to have no particular problems. The concentration of carbon monoxide, carbon dioxide, and nitrogen dioxide in the air was also maintained without any unusual factors compared to the concentration in the ordinary atmosphere. However, the library is a multi-use facility that needs regular cleaning and ventilation to manage the environment.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.1
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• pp.17-24
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• 2014

We measured black carbon concentration in rural area to understand the characteristic of atmospheric aerosol by comparing the black carbon concentration and meteorological factors such as PM10 concentration, relative humidity, temperature and wind velocity. A MAAP (Multi Angle Absorption Photometer) which is one of filter based equipments was used to measure black carbon concentration. Black carbon concentration was measured to be high from April to May and low from June to September. Black carbon concentration was proportional to PM10 concentration. Black carbon concentration was correlated to relative humidity. Black carbon concentration was inversely proportional to wind velocity and temperature. Finally, we suggest that the volume fraction of black carbon in the atmosphere can be estimated from the size, number concentration and absorption coefficient measured using the MAAP.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.7
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• pp.42-49
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• 1999

In this paper, we proposed a simple measurement method to find the behaviors of the fiber-to-waveguide coupler. The polished fiber blocks and planar waveguides on silicon dioxide were fabricated independently and then optically coupled by physical pressure. Several kinds of polymer with different refractive indices were used for waveguide films. The proposed method makes it possible to measure the center wavelength, bandwidth, extinction ratio, and polarization dependence of the coupler during fabrication procedure. The wavelength sensitivity increased with refractive index of polymer. The symmetric planar waveguide structure and isotropic property of guiding materials reduced polarization dependent property. Insertion loss of the coupler was less than 0.5dB. It is expected that our measurement method is useful for developing various optical devices using evanescent coupling between polished fiber and planar waveguide such as optical modulators and filters etc.

• Analytical Science and Technology
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• v.25 no.4
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• pp.230-235
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• 2012

It is to use many plastic materials as living essential goods. But when the fire is happened, owing to noxious gases, many men should be injured. Therefore as the noxious gases are measured by open path FT-IR spectrometer as remote monitoring, the demage of men could be minimized. Such this system consists of a Fourier transform spectrometer and infrared lamp fitted to long length. The study was to do the quantitative analysis on CO, $NO_2$, HCl, HF gas by remote monitoring open path FT-IR spectrometer. And the method of it should use MLR (multiple linearity regression) method. As result, It was confirmed to be more than 0.95 as $R^2$ of MLR. And then Urethane and PVC of plastic materials selected was burned, the concentration of polluted gases were measured by remote monitoring method.

• Korean Chemical Engineering Research
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• v.43 no.2
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• pp.215-221
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• 2005

A Fe-containing mesoporous silica (Fe-MCM-41) in which part of Si in the framework was replaced by Fe(Si-O-Fe) has been successfully prepared using $Fe^{3+}$ salt by a direct synthesis route. Physical properties of the material were characterized by XRD, $N_2$ adsorption, SEM/TEM, UV-vis and FT-IR spectroscopies. Fe-MCM-41 exhibited high catalytic activity in phenol hydroxylation using $H_2O_2$ as oxidant, giving phenol conversion of ca. 60% at $50^{\circ}C$ [phenol : $H_2O_2$ = 1:1, water solvent]. Fe-MCM-41 was also applied to the growth of CNTs, utilizing a thermal-CVD reactor using acetylene gas, which demonstrated that multi-wall CNTs could be prepared efficiently using the Fe-MCM-41 catalyst.

• Journal of Radiation Protection and Research
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• v.30 no.1
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• pp.35-37
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• 2005

The radiation detector research group at KAERI has developed a high efficiency neutron detector using a Gas Electron Multiplier (GEM). The double GEM was fabricated and operated in an Ar/Isobutane mixture. For an application to a high efficiency neutron detector, $^6Li\;or\;^{10}B$ neutron converters coated on each surface of the multi GEM foils were considered. The optimized thickness of the thin film for a neutron detection was calculated with the MCNP and SRIM. The neutron efficiency was calculated by changing the chemical components of the thin film, and the thickness of the thin film. The thermalized neutrons were measured by a GEM detector with a thin neutron converter on the drift plate.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.3
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• pp.220-226
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• 2019

Magnesium hydride has a high hydrogen storage capacity (7.6 wt.%), and is cheap and lightweight, thus advantageous as a hydrogen storage alloy. However, Mg-based hydrides undergo hydrogenation/dehydrogenation at high temperature and pressure due to their thermodynamic stability and high oxidation reactivity. MWCNTs exhibit prominent catalytic effect on the hydrogen storage properties of $MgH_2$, weakening the interaction between Mg and H atoms and reducing the activation energy for nucleation of the metal phase by co-milling Mg with carbon nanotubes. Therefore, it is suggested that combining transition metals with carbon nanotubes as mixed dopants has a significant catalytic effect on the hydrogen storage properties of $MgH_2$. In this study, Material life cycle evaluation was performed to analyze the environmental impact characteristics of Mg-CaO-10 wt.% MWCNTs composites manufacturing process. The software of material life cycle assessment (MLCA) was Gabi 6. Through this, environmental impact assessment was performed for each process.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.485-491
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• 2021

This study examined the effects of preschool teachers' social support and mindfulness on job exhaustion. The study subjects were 138 preschool teachers in OO city. As an analysis method, frequency analysis, reliability analysis, and correlation analysis were performed using the SPSS 22.0 program, and multiple regression analysis was performed on the causal relationship between the variables. An examination of the effect of social support on preschool teachers on job exhaustion found that the material support factor, a sub-factor of social support, had a negative effect (-) on job exhaustion. Second, the sub-factors of mindfulness, decentered attention, and present awareness had a significant negative effect on job exhaustion. A higher the current awareness, the decentered attention of mindfulness, and the material support factor of social support perceived by preschool teachers indicated lower job exhaustion. These results provide the basic data for the preparation of measures for reducing job exhaustion of preschool teachers.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.419-419
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• 2023

하천의 최종 유출부와 해양이 만나는 지점을 하구라고 하며, 우리나라는 주로 서해안 지역에 하구 방조제 건설에 따른 담수호가 조성되어 다양한 목적으로 수자원이 활용되고 있다. 이러한 하구 담수호는 바다로 유입되기 직전의 물을 저류시켜 수자원 확보에 긍정적이나, 일반적으로 유역의 최하류에 위치해 있어 오염물질 유입, 부영양화, 염분 침출로 인한 오염물질 용출 등에 취약하다. 따라서 담수호의 회복탄력성 향상과 지속가능한 수자원 관리를 위해서는 미래 기후변화에 따른 영향 분석이 필수적이다. 특히 기후변화는 거대규모의 홍수과 같은 자연재난, 농업가뭄 및 식생가뭄 등의 증가로 이어질 수 있으므로, 이에 효과적으로 대비하기 위해서는 미래 기후조건에 따른 하천의 미래 유출량 변화 예측이 수행되어야 한다. 본 연구에서는 불확실한 미래 수문변화를 예측하기 위해 CMIP6(Coupled Model Intercomparison Project Phase 6) GCMs(Global Climate Models)의 SSP(Shared Socioeconomic Pathways) 시나리오를 유역 유출모델에 적용하여 기후변화에 따른 미래 유출특성의 변화를 예측하였다. 충청남도 서산시에 위치한 간월호 유역을 대상유역으로 선정하고, HSPF(Hydrological Simulation Program-FORTRAN) 모형을 적용하여 상류유역의 과거 및 미래 장기유출량 모의를 수행하였다. 모의된 시나리오별 유출량을 기반으로 최빈유량곡선법을 적용하여 미래의 기준유량 발생시점 및 지속기간의 변화를 분석하였으며, CVDs(Center-of-volume dates)의 변화를 통해 기후변화에 따른 홍수기의 시기적 변화 양상을 파악하고자 하였다. 본 연구의 결과는 미래 유역 환경변화를 고려한 담수호의 수자원 보전관리계획 수립에 있어 기초자료로 활용될 수 있을 것으로 기대된다.

• Journal of Korea Entertainment Industry Association
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• v.13 no.6
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• pp.287-295
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• 2019

The purpose of this study was to identify the factors affecting mental health status according to gender of persons with physical disabilities and to try their healthy life. Using the 6th Korean Retirement and Income Study, 333 persons with physical disabilities were included in the study. Descriptive statistics, t-test, and regression analysis were conducted to examine the general characteristics, instrumental activities of daily living, material support, and the effects on mental health status. There was no statistically significant difference in mental health status by gender, but there was a difference in Instrumental Activities of Daily Living and life satisfaction. In the case of males, instrumental daily activities performance, material support, depression, and life satisfaction were found to be influential. In the case of females, spouse, depression, and life satisfaction were factors affecting mental health status. Based on the results of this study, we will be able to understand persons with physical disabilities and use them as a basis for developing mental health promotion programs.