• 한국환경복원기술학회지
• /
• 제24권1호
• /
• pp.25-36
• /
• 2021

The honey bee has a crucial ecological status for maintaining the natural ecology system. Pollination mediations by honey bees are recognized as an efficient way to enhance the quality of biological diversity and green areas in the nature and the urban ecological system. However, the population of bee around the world is decreasing and we do not know exactly how bees react to the physical environment in the urban area. This study is a basic research for the improvement of pollination services in the Korean urban ecological system. It aims to induce and review environmental variables which have high relations with the activities of pollination mediation insects in the urban area. The study established a Maxent model using five urban environmental variables that reflect the ecology of Bombus ignitus and the place information where Bombus ignitus appears in 18 spots of Seoul city, and compared with previous research results on Apis millifera. Bombus ignitus preferred places with more natural environments such as mountain forest areas and vicinities of streams. They preferred Stratified Tree Area the most among the vegetation types existing in the urban area. Comparing chicken models, both species saw their response value drop as the building coverage rose. In the case of Apis millifera and Bombus ignitus variables, the response value of both species was high in 10 out of 20 types. The result of this study is expected to provide basic information for improving the pollination services in the Korean urban area and to be utilized as the basic materials for the future urban planning.

• 공업화학
• /
• 제32권1호
• /
• pp.102-109
• /
• 2021

Recently, an interest in risk calculation methods has been increasing in Korea due to the establishment of classification code for explosive hazardous area on gas facility (KGS CODE GC101), which is based on the international standard of classification of areas - explosive gas atmospheres (IEC 60079-10-1). However, experiments to check for leaks of combustible or toxic gases are very difficult. These experiments can lead to fire, explosion, and toxic poisoning. Therefore, even if someone tries to provide a laboratory for this experiment, it is difficult to install a gas leakage equipment. In this study we find out differences among actual experiments, CFD by using FLACS and calculation based on classification code for explosive hazardous area on gas facility (KGS CODE GC101) by comparing to each other. We develpoed KGS HAC (hazardous area classification) program which based on KGS GC101 for convenience and popularization. As a result, actual gas leak, CFD and KGS HAC are showing slightly different results. The results of dispersion of 1.8 to 2.7 m were shown in the actual experiment, and the CFD and KGS HAC showed a linear increase of about 0.4 to 1 m depending on the increase in a flow rate. In the actual experiment, the application of 3/8" tubes and orifice to take into account the momentum drop resulted in an increase in the hazardous distance of about 1.95 m. Comparing three methods was able to identify similarities between real and CFD, and also similarities and limitations of CFD and KGS HAC. We hope these results will provide a good basis for future experiments and risk calculations.

• Korean Chemical Engineering Research
• /
• 제60권2호
• /
• pp.308-312
• /
• 2022

3D 프린팅 기술은 다양한 재료를 적층하여 구조물을 제작할 수 있으며, 다양한 장점을 바탕으로 최근 제조분야에 널리 활용되고 있다. 특히 고해상도의 액적 기반 3D 프린팅 기술은 주로 광경화성 물질을 사용하여 액적을 증착해 나가며 최종 구조물을 형성한다. 물질의 광경화 특성으로 인해 프린팅 과정에서 발생할 수 있는 빛 노출에 따라 액적의 물성 및 증착 특성이 달라질 수 있다. 이에 본 연구에서는 광경화성 하이드로겔 액적의 빛에너지 조사 조건에 따른 액적의 점도변화 및 표면과의 퍼짐 거동에 관해 실험적으로 관찰 및 분석을 수행하였다.

• 한국엔터테인먼트산업학회논문지
• /
• 제14권3호
• /
• pp.105-115
• /
• 2020

최근 대학입학 학령인구의 감소에 따라 입학생 모집에 큰 어려움이 예상되고 있다. 대학알리미에 공시된 전국 4년제 대학의 최근 3년간(2016-2018)의 중도 탈락률은 4.1%(217개 대학 기준), 4.3%(214개 대학 기준), 4.6%(212개 대학 기준)으로 매년 지속적으로 증가하고 있어, 대학의 당면한 가장 큰 현안으로 대두되고 있다. 본 연구에서는 H대학에서의 대규모 실증 연구를 통해 대학생의 중도탈락의도에 대한 분석과 그 의도에 영향을 미치는 교육 요인을 도출하였다. 먼저 중도탈락의도에 대한 분석결과, 공과계열 학생의 중도탈락의도가 인문계열에 비해서 높고, 고학년 일수록 높게 나타났다. 특성화고 출신이 일반고에 비해서 높았으며, 본인이 등록금을 마련하는 학생들이 그렇지 않은 경우에 비해서 높게 나타났다. 중도탈락 의도에 대한 요인분석결과 수업곤란도, 전공 만족, 학부모 만족, 국제화 만족, 대학교육성과 만족 순으로 중도탈락의도에 큰 영향을 미치는 것으로 분석되었다.

• 대한본초학회지
• /
• 제29권2호
• /
• pp.55-60
• /
• 2014

Objectives : The aim of this study was to evaluate whether herb mixture extract (HME) would affect allergic contact dermatitis induced by 1-chloro-2,4-dinitro-chlorobenzene (DNCB) in mice. For this, the level of blood IgE was identified. To evaluate anti-inflammatory effect of HME, we tested HMC-1 cells stimulated by PMA+A231867. Methods : In order to evaluate allergic contact dermatitis effects we observed HME on contact-hypersensitive skin of Balb/cmice induced by 0.5% DNCB and measured concentration of IgE in blood of Balb/c mice. In order to evaluate anti-inflammatory effect of cytokine expression we used the method of enzyme-linked immunosorbent assay. Results : We confirmed deep wounds, erosions, progress of keratinization and drop out of dead skin cells from Balb/c mice induced by 0.5% DNCB. We also observed a remarkable decrease in symptoms of atopic dermatitis in the group that received injection of 200mg/kg HME. In addition, in the measurement outcome for IgE concentration in blood, we confirmed that IgE concentration was increased by treatment with DNCB only, while it was markedly decreased by treatment with HME. We confirmed that cytokine expression decreased through enzyme-linked immunosorbent assay and pERK, pJNK, and pp38 also decreased through western blot test Conclusions : According to the above results, HME has some effect on alleviating symptoms of allergic contact dermatitis and has anti-inflammatory effects.

• 한방안이비인후피부과학회지
• /
• 제35권1호
• /
• pp.24-37
• /
• 2022

Objectives : The purpose of this literature review is to analyze process of manufacture and formulation and toxicity of Geumgweyoryak(金匱要略)'s external applicants for modern and safe using. Methods : This study used the Geumgweyoryak(金匱要略) reprinted by Zhao Kaimei(趙開美) as basic data for a understanding of the manufacture and formulation and toxicity for external applicants. Among the 25 chapters, the 22 chapters were studied except for the last three chapters, which are known to be written by later writers. Based on the above, Geumgweyoryeok(金匱要略)'s external applicants was analyzed the process of manufacture, formulation and the toxicity. Results : There are 11 types of external applicants of Geumgweyoryak(金匱要略). Washing method(洗法) was used 2 times, Drop method(瀝法) was used 1 time, Smoke method(熏法) was used 2 times, Rubbing method(摩法) was used 1 time, Plaster method(敷法) was used 2 times, Invading method(浸法) was used 1 time, Suppository method (坐法) was used 2 times, Flatiron method(烙法) was used 1 time. According to classified the modern formulation, there are 4 types of powder formulation, 4 types of liquid formulation, 2 types of suppository, and 1 type of Semi-solid formulation. Especially toxic drugs, such as Realgar(雄黃) or Hydrocerussite(鉛粉), should be careful. When Realgar(雄黃) smokes, a toxic substance called AS2O3 can come out. Hydrocerussite(鉛粉) can cause lead poisoning. Lead increases the risk of anemia, dehydration, and lead neuropathy when chronically exposed. Conclusion : We supposed that this study can serve as a basic data to help clinical Korean doctors to use the prescription for external applicants more safely and to easily apply it in the form of external applicants.

• 한국입자에어로졸학회지
• /
• 제18권3호
• /
• pp.79-86
• /
• 2022

Many commercial air purifiers currently have deployed granular activated carbon (GAC) filters for removing volatile organic compounds in the indoor air. GACs are generally used to remove gaseous contaminants in the air through adsorption by the inner surfaces of pores. In addition, airborne particles can be also filtered by the surface adsorption of the GACs, which can improve the life-time of the particulate filters. In this study, the filtration efficiency of GACs to ultrafine particles through surface adsorption was investigated at different volume flow rates by deploying a continuous particle filtration system. The polydisperse sodium chloride (NaCl) particles were generated by a set of an atomizer and a diffusion dryer, and then mixed with particle-free air at different volume flow rates. The penetration of ultrafine particles and pressure drop for each experimental condition were measured to figure out the effect of the volume flow rate on the surface adsoprtion of the GACs to particles, ~ 2 mm. The particle filtration efficiency of the GACs decreased as the volume flow rate increased from 4 to 14 lpm. However, the 5 times thicker GAC filter layer decreased the penetration of ultraparticles than a preious study. The filtration efficiency of the single granule was also higher than the previous result in the literature with smaller granule filter materials.

• 지질공학
• /
• 제32권4호
• /
• pp.499-511
• /
• 2022

본 연구에서는 ETAG 027에서 제시하는 수직낙하실험법을 이용하여 100 kJ 낙석에너지를 포획할 수 있는 유연성 와이어로 낙석방지울타리에 대한 성능검증을 실시하였다. 유연성 와이어로프는 스프링과 와이어로프로 구성된 탄성력 증진 로프로서 와이어로프보다 탄성늘음이 향상되어 낙석과 와이어로프와의 접촉시간을 인위적으로 증가시켜 낙석 충격력 경감효과를 유발하고 낙석에너지 흡수효과 또한 향상시켰다. 9.8 kN의 콘크리트 공시체를 낙석방지울타리 상단 10.5 m 높이에서 자유낙하시켜 102.9 kJ의 낙석에너지를 낙석방지울타리에 가한 후 지주거동을 분석한 결과, 지주는 소성비틀림이 발생하였으며 탄성회복 후 최종변형량은 1.15 m로 ETAG 027에서 제시하는 기준인 2.0 m 이하의 결과가 제시되어 유연성 와이어로프 낙석방지울타리는 102.9 kJ의 낙석에너지를 성공적으로 흡수 가능한 것으로 확인되었다.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제13권1호
• /
• pp.599-616
• /
• 2021

The semi-submersible with three circular columns is an original concept of efficient multifunctional platform, which can be used for marginal oil, gas field, and Floater of Wind Turbines (FOWT). However, under certain flow conditions, especially in uniform current with specific velocities, the eddies will alternatively form and drop behind columns, resulting in the fluctuating lift force and drag force. Consequently, the semi-submersible will subject to the Flow-Induced Motions (FIM). Based on the Detached Eddy Simulation (DES) method, the numerical studies were carried out to understand the FIM characteristics of the three-column semi-submersible at two different parameters, i.e., current incidences (0°, 30°, and 60°-incidences) and reduced velocities (4 ≤ U_r ≤ 14). The results indicate that the lock-in range of 6 ≤ U_r ≤ 10 for the transverse motions is presented, and the largest transverse non-dimensional nominal amplitude is observed at 60°-incidence, with a value of A_y/D = 0:481. The largest yaw amplitude A_yaw is around 3.0° at 0°-incidence in the range of 8 ≤ U_r ≤ 12. The motion magnitude is basically the same as that of a four-column semi-submersible. However, smaller responses are presented compared to those of the three-column systems revealing the mitigation effect of the pontoon on FIM.

• The Korean Journal of Pain
• /
• 제35권3호
• /
• pp.291-302
• /
• 2022

Background: Spinal cord injury (SCI) is one of the most debilitating disorders throughout the world, causing persistent sensory-motor dysfunction, with no effective treatment. Oxidative stress and inflammatory responses play key roles in the secondary phase of SCI. Naringenin (NAR) is a natural flavonoid with known anti-inflammatory and antioxidative properties. This study aims at evaluating the effects of intrathecal NAR administration on sensory-motor disability after SCI. Methods: Animals underwent a severe compression injury using an aneurysm clip. About 30 minutes after surgery, NAR was injected intrathecally at the doses of 5, 10, and 15 mM in 20 µL volumes. For the assessment of neuropathic pain and locomotor function, acetone drop, hot plate, inclined plane, and Basso, Beattie, Bresnahan tests were carried out weekly till day 28 post-SCI. Effects of NAR on matrix metalloproteinase (MMP)-2 and MMP-9 activity was appraised by gelatin zymography. Also, histopathological analyses and serum levels of glutathione (GSH), catalase and nitrite were measured in different groups. Results: NAR reduced neuropathic pain, improved locomotor function, and also attenuated SCI-induced weight loss weekly till day 28 post-SCI. Zymography analysis showed that NAR suppressed MMP-9 activity, whereas it increased that of MMP-2, indicating its anti-neuroinflammatory effects. Also, intrathecal NAR modified oxidative stress related markers GSH, catalase, and nitrite levels. Besides, the neuroprotective effect of NAR was corroborated through increased survival of sensory and motor neurons after SCI. Conclusions: These results suggest intrathecal NAR as a promising candidate for medical therapeutics for SCI-induced sensory and motor dysfunction.