• Wind and Structures
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• 제22권5호
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• pp.555-571
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• 2016

A hanging-type sand-retaining wall is a very common sand-blocking fence structure used to prevent sand movement. This type of wall is widely used along the Qinghai-Tibet and Gobi desert railways in Xinjiang, Western China. To analyze the characteristics of wind-sand flow fields under the effect of such a sand fence structure, a wind tunnel test and a field test were carried out. The wind tunnel test showed the zoning characteristics of the flow fields under the effect of the hanging-type sand-retaining wall, and the field test provided the sediment transport data for effective wind-proof interval and the sand resistance data in the front and behind the sand-retaining wall. The consistency of the wind-sand flow fields with the spatial distribution characteristic of wind-carried sand motion was verified by the correspondences of the acceleration zone in the flow field and the negative elevation points of the percentage variations of the sand collection rate. The spatial distribution characteristic of the field sand collection data further showed the spatial structural characteristic of the sandy air currents under the action of the hanging-type sand-retaining wall and the sand resistance characteristic of the sand-retaining wall. This systematic study on the wind-sand flow fields under the control of the hanging-type sand-retaining wall provides a theoretical basis for the rational layout of sand control engineering systems and the efficient utilization of a hanging-type sand-retaining wall.

• Membrane and Water Treatment
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• 제6권3호
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• pp.225-235
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• 2015

During low-pressure membrane treatments of cyanobacterial cells, including microfiltration (MF) and ultrafiltration (UF), there have reportedly been releases of intracellular compounds including cyanotoxins and compounds with an earthy-musty odor into the water, probably owing to cyanobacterial cell breakage retained on the membrane. However, to our knowledge, no information was reported regarding the effect of growth phase of cyanobacterial cells on the release of the intracellular compounds. In the present study, we used a geosmin-producing cyanobacterium, Anabaena smithii, to investigate the effect of the growth phase of the cyanobacterium on the release of intracellular geosmin during laboratory-scale MF experiments with the cells in either the logarithmic growth or stationary phase. Separate detection of damaged and intact cells revealed that the extent of cell breakage on the MF membrane was almost the same for logarithmic growth and stationary phase cells. However, whereas the geosmin concentration in the MF permeate increased after 3 h of filtration with cells in the logarithmic growth phase, it did not increase during filtration with cells in the stationary phase: the trend in the geosmin concentration in the MF permeate with time was much different between the logarithmic growth and stationary phases. Adsorption of geosmin to algogenic organic matter (AOM) retained on the MF membrane and/or pore blocking with the AOM were greater when the cells were in the stationary phase versus the logarithmic growth phase, the result being a decrease in the apparent release of intracellular geosmin from the stationary phase cells. In actual drinking water treatment plants employing membrane processes, more attention should be paid to the cyanobacterial cells in logarithmic growth phase than in stationary phase from a viewpoint of preventing the leakage of intracellular earthy-musty odor compounds to finished water.

• 한국태양에너지학회 논문집
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• 제39권6호
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• pp.127-135
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• 2019

In this study, we analyzed the relationship between five factors: long-wave radiation, short-wave radiation, cloudiness, SVF and summer shelters. In the previous study, we recognized the correlation between single building SVF and long-wave radiation. Furthermore, this study attempted to confirm the relationship at the summer shelter with high solar radiation blocking rate. The observations are as follows. ① Cooling in summer shelters was not the effect of temperature but the effect of radiation reduction due to short-wave radiation shielding. ② In the case of the canopy tent with low heat capacity, the long-wave radiation was observed to be 16.7% higher per hour than the comparison control point due to the increase in surface temperature. ③ The long-wave radiation increase rate was different according to SVF, but showed very similar pattern according to the material characteristics of the summer shelters. ④ Passive Cooling effect on the type of summer shelters are determined by the size of the total long and short-wave radiation at that point.

• 약학회지
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• 제22권3호
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• pp.163-174
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• 1978

차전자(Plantaginis Semen)은 우리나라 전국 각지의 원야와 노방의 자생하는 다년생 초목으로 Plantaginaceae(질경이과)에 속하는 Plantago major L. var. asiatica Decaisne 질경이의 종자를 말하며 그의 성분으로는 다량의 점액, 지방유, pentosan 및 galactan, succinic acid, plantanolic acid, adenine, choline. K-염등이 알려져 있다. 이 차전자는 한방과 민간에서 소염, 이뇨, 진해, 지사제로서 널리 사용되어 왔으며 그의 약리작용에 관해서는 이미 저자들이 가토를 이용한 실험에서 이의 methanol extract가 자궁수축작용, 호흡흥분작용, 혈압강하작용, 장관수축작용, 심장박동의 완제작용, 항이뇨작용이 있음을 보고한 바 있다. 그러나 그의 기전에 관해서는 거의 알려진 바가 없다. 따라서 저자들은 위의 여러가지 작용중 특히 혈압강하작용에 관한 본태를 파악하여 그의 실용성 여부를 구명코자 이 실험을 착수하였다.

• 환경영향평가
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• 제21권1호
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• pp.25-39
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• 2012

This study was aimed to assess the effects of additional installation of two different types of weirs, one is a curtain-type weir and another is a submerged-type weir, on the control of algal growth in Daechung Reservoir. A two-dimensional(2D) coupled hydrodynamic and eutrophication model that can accommodate vertical movement of the curtain weir following the water surface variations was verified using field data obtained in two distinctive hydrological years; dry(2008) and wet(2010). The model adequately simulated the temporal and spatial variations of water temperature, nutrients and algal(Chl-a) concentrations during the periods. The effectiveness of curtain weir on the control of algal bloom was evaluated by applying the model to 2001(dry year) and 2010 assuming 6 different scenarios according to installation locations. The curtain weirs that already installed at 3, 5, 7 sites(scenario C-2) showed significant effect on the control of algal growth in the reservoir; the reduction rates of algal concentration were placed in the range of 7.5~31.5% and 9.1~44.9% for 2001 and 2010, respectively. However the simulation results revealed that additional installation of curtain weirs(scenario C-3~C-6) in the bay area (choosori) have marginal effect. The effectiveness of submerged weir was evaluated against 2010 assuming 7 different scenarios according to installation locations, but all scenarios(S-1~S-7) showed neglectable or negative effect on the control of algal growth.

• 멤브레인
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• 제30권2호
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• pp.131-137
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• 2020

본 연구에서는 가압식 분리막 여과에서 무기입자의 존재가 유기파울링에 미치는 영향을 관찰하였다. 유기파울링의 유발을 위해 알긴산나트륨(sodium alginate, SA)를 이용한 정밀여과 실험에서 무기 실리카(SiO₂) 입자의 존재 유무와 상관없이 분리막 파울링은 여과초기 완전공극막힘에서 여과시간이 경과할수록 케이크 형성에 의해 주로 지배되었다. 그러나 무기입자의 존재 시 정압여과에서 알긴산나트륨 파울링 케이크 비저항값과 압축성은 상대적으로 낮게 관찰되었고 이로 인해 낮은 파울링 속도가 관찰되었다. 동일한 시료를 이용한 정량여과 실험을 수행한 결과 정압여과에 비해 정량여과에서 여과초기 공극막힘현상 및 파울링 속도는 더욱 증가하였다. 이와 같은 현상은 파울링층이 지닌 압축성으로 막간차압의 증가 시 케이크 비저항값이 함께 증가하였기 때문인 것으로 판단된다. 알긴산나트륨과 실리카 입자가 함께 존재 시 알긴산나트륨이 단독으로 존재하는 것보다 수리학적 세정을 통한 파울링 제거효과는 더욱 좋은 것으로 관찰되었다.

• 동의생리병리학회지
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• 제17권4호
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• pp.1031-1036
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• 2003

To certify the protective effect of herbal medicine against oxygen free radical-induced myocardiotoxicity, cytotoxicity was measured using TBARS assay and Beating rate in the presence of Tongryeong-san(TRS) extracts or single constituents of this prescription. Myocardial toxicity was evaluated in neonatal rat myocardiocytes in cultures. In the present study, xanthine oxidase/hypoxanthine (XO/HX) resulted in a increase in lipid peroxidation and decreases in beating rate in cultured myocardial cells. In the effect of TRS extract, it showed the prevention from the XO/HX-induced cardiotoxicity by the increases of beating rate as well as the decrease of lipid peroxidation, In the protective effect of Faeces Trogopterori(FT), Pollen Typhae(PT), Caulis Akebiae(CA) and Radix Paeoniae Rubra(PRR), all the extracts were significantly effective in the protection of XO/HX-induced cardiotoxocity in cultured myocardial cells by the increase of beating rate as well as th decrease of lipid peroxidation. From these results, they show that XO/HX is cardiotoxic in cultured myocardial cells derived from neonatal rat, and it suggests that TRS, FT, PT, CA and PRR extracts are positively effective in the blocking in XO/HX-induced cardiotoxicity.

• 동의생리병리학회지
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• 제21권3호
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• pp.617-625
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• 2007

Samul-Tang (SMT) has been used for nourishing of the blood, hematopoiesis as a herbal medicine history. The purpose of this study is to find out anti-allergic inflammatory reaction of SMT. To clarify the mechanism, the effect of SMT on vascular permeability of rat cutaneous tissue and histamine and cytokines (IL-6, IL-8, TNF-${\alpha}$) release from mast cells were observed. The results are the pretreatment with SMT significantly decreased the compound 48/80-induced degranulation and histamine release from RPMC, SMT also inhibited the anti-DNP lgE-induced increment of vascular permeability of rat cutaneous tissue. SMT significantly reduced the PMA plus A23187-induced increment of expression of IL-6, IL-8, and TNF-${\alpha}$ in HMC-1 Cell. The Present study provide evidence that SMT inhibits mast cell-derived inflammatory allergic reactions by blocking histamine release and pro-inflammatory cytokine expression, and suggest the mechanisms of action. Furthermore, in vivo and in vitro anti-allergic effect of SMT suggests a possible therapeutic application of this agent in inflammatory allergic diseases.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
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• pp.337-347
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• 2006

Papers made from unbleached and bleached bagasse chemimechanical pulp were chemically modified by acetylation. The effects of irradiation on unbleached and bleached also reduced papers of bagasse chemimechanical pulp before and after acetylation were investigated in this study. Chemimechanical pulp was prepared from bagasse and then bleached with hydrogen peroxide. Unbleached and hydrogen bleached pulps were reduced by Sodium borohydride in different procedures. Paper sheets were prepared from pulps and then acetylated using a technical grade of acetic anhydride. Accelerated photo-aging was run on the samples using fluorescent lamps to verify photo-stability of paper sheets before and after pretreatments. Brightness reversion (as Post-color number) and other optical properties of the paper sheets were measured. Efficient inhibition of photo-yellowing of papers made from bagasse CMP was achieved by acetylation. The acetylated unbleached CMP was noticeably photo-bleached during irradiation. Sodium borohydride reduction followed by acetylation had the same effect as acetylation alone at the same degree of reaction time and reductive treatment did not affect the yellowing rate to any great extent. The pre-reduced, acetylated unbleached papers were, however, not brightened during irradiation. Calculation done by Kubelka-Munk equation showed that reductive treatment had little effect in reducing the photo-yellowing of paper made from CMP pulp; a small stabilization effect was observed in the case of bleached CMP, while unbleached CMP was slightly more prone to discolor in the later phase of photo-reversion. The improved stability towards light may was closely related to the decrease in the phenolic hydroxyl content as a result of blocking by acetyl groups during treatment with acetic anhydride. The results support the hypothesis that phenolic hydroxyl has an important role in the process of photo-reversion of high-yield pulps. The results obtained in this study demonstrate that the acetylation of paper manufactured from peroxide bleached Bagasse CMP significantly retards light-induced discoloration. The inhibition of yellowing is connected with a decrease in the phenolic hydroxyl content of both unbleached and peroxide bleached papers.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 추계학술대회
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• pp.65-65
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• 2019

In this study, we evaluated the anti-inflammatory effect of extracts of leaves (LCLE) and branches (LCBE) from L. caerulea in LPS-stimulated RAW264.7 cells. Inhibitory effect of LCLE and LCBE against LPS-induced overproduction of NO, iNOS and $IL-1{\beta}$ was higher than LCFE. Furthermore, LCLE and LCBE significantly inhibited the overexpression of COX-2, IL-6 and $TNF-{\alpha}$ in LPS-stimulated RAW264.7 cells. LCLE and LCBE did not inhibited LPS-induced degradation of $I{\kappa}B-{\alpha}$, but blocked the nuclear accumulation of p65. LCLE did not inhibited LPS-induced phosphorylation of ERK1/2 and p38, while LCBE significantly attenuated phosphorylation level of p38. LCLE and LCBE increased HO-1 protein level and decrease of iNOS and $IL-1{\beta}$ expression by LCLE and LCBE was inhibited by HO-1 knockdown. The inhibition of p38 by SB203580 and ROS by NAC blocked HO-1 expression by LCLE and LCBE. LCLE and LCBE increased p38 phosphorylation and the inhibition of ROS by NAC blocked p38 phosphorylation LCLE and LCBE. LCLE and LCBE induced nuclear accumulation of Nrf2, but this was significantly reversed by the inhibition of p38 and ROS. In addition, LCLE and LCBE increased ATF3 expression and decrease of iNOS and $IL-1{\beta}$ expression by LCLE and LCBE was inhibited by ATF3 knockdown. Collectively, LCLE and LCBE inhibited LPS-induced $NF-{\kappa}B$ activation by blocking p65 nuclear accumulation, increased HO-1 expression by ROS/p38/Nrf2 activation, and increased ATF3 expression. Furthermore, LCBE inhibited LPS-induced p38 phosphorylation.