• Title/Summary/Keyword: blockage

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Road Runoff Treatment using Pilot Scale-NPS Treatment Plant Filling up Expended Polypropylene Media (발포고분자여재가 충전된 파일럿 규모의 비점오염물질 처리장치를 이용한 도로 강우유출수 처리)

  • Kim, Seogku;Oh, Hyecheol;Ahn, Jaehwan
    • Journal of Korean Society of Environmental Engineers
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    • v.36 no.10
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    • pp.711-718
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    • 2014
  • Investigated the processing characteristics of the pollutants and runoff due to storm events in the actual application of the road fields and a Non-Point Sources (NPS) pilot scale equipment. This phenomenon has occurred in the influent bypass the blockage occurs after 90 min the expended polymeric media was filled with filtered column. When entering a treatment tank SS 200 mg/L or more high concentration of effluent treatment efficiency was reduced from the reaction time 60 min. Influent concentration less then SS 180 mg/L was stable handling. The $COD_{Cr}/SS$ ratio were analyzed with 0.67, median value. Showed 92.1% and 82.3% respectively with an average removal rate of the SS and the $COD_{Cr}$. If the influent concentration of TP is the 0.5 mg/L or less, the quality of the treated water is 0.1 mg/L levels were expressed in a stable process. And when entering the 1.0 mg/L or more of the treated water, had a greater than average 0.2 mg/L. If the influent concentration of TN is 4~10 mg/L, the treatment water quality level was kept a 1.5~3.0 mg/L. The average removal efficiency of TP and TN respectively 73.9%, 50.4%.

Systematic Review : Comparative Safety and Efficacy of Mono- and Combination Therapy of Anti-hypertensive Agents Acting on the Renin-Angiotensin System (레닌-안지오텐신계에 작용하는 항고혈압 약제의 단독요법과 병용요법의 안전성 및 유효성에 대한 체계적 문헌고찰)

  • Choi, Kyung-Eob;Kim, Hyun-Kyung
    • Korean Journal of Clinical Pharmacy
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    • v.21 no.4
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    • pp.364-375
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    • 2011
  • Given that single blockade with angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) can achieve only partial and undurable suppression of the Renin Angiotensin System (RAS), it has been hypothesized that dual blockage would be more beneficial in the management of blood pressure (BP) reduction and prevention of progressive chronic kidney disease (CKD) than either agent alone. Thus, it has been suggested that the combination of an ACEI and an ARB might provide renal benefits to hypertensive patients over and above BP reduction. However, this might also expose patients to additive or synergistic side effects. We attempted to conduct a systematic review to evaluate the benefits and harms of combination therapy in hypertensive patients with or without kidney diseases. MEDLINE and KoreaMed were searched for relevant randomized clinical trials in adult hypertensive patients with or without diabetes (restricted to 1997, limited to trials published in English). Results were summarized using the random-effects model, and between-studies heterogeneity was estimated with $I^2$. A final analysis of ten trials (23,928 patients) revealed that the combination of an ACEI and an ARB reduced blood pressure (SBP/DBP) by 3.95/2.02 mmHg (95% confidence interval [CI], -4.38 to -3.53/-2.33 to -1.71) compared with ACEI monotherapy, and 2.83/2.64 mmHg (95% CI, -3.25 to -2.41/-4.95 to -0.33) compared with ARB monotherapy. Eight trials (391 patients) demonstrated a significant reduction in 24h-proteinuria (weighted mean difference, 0.16 g/day, 95% CI, -0.26-0.05), but they did not translate into an improvement in GFR. Tests for heterogeneity showed no difference in effect among the studies. The combination therapy reduced proteinuria by 30% (95% CI, 23% to 37%) and 39% (95% CI, 31% to 48%) compared with ACEI monotherapy and ARB monotherapy, respectively. However, in patients who had proteinuria more than 0.5 g/day, the combination therapy failed to show significant reduction in urinary protein excretion. The current cumulative evidence suggests that diabetic patients with proteinuria on dual RAS blockade have an increase risk of adverse events such as hyperkalemia, hypotension, and so on, compared with ACEI or ARB alone. It is, therefore, proposed that the combination therapy should not be routinely used for the treatment of hypertension with or without compelling indications.

Absolute Age Determination of One of the Oldest Quaternary(?) Glacial Deposit (Bunthang Sequence) in the Tibetan Plateau Using Radioactive Decay of Cosmogonic $^{10}Be$ and $^{26}Al$, the Central Kavakoram, Pakistan: Implication for Paleoenvironment and Tectonics (방사성 우주기원 동위원소를 이용한 티벳고원에서 가장 오래된 제4기(?) 빙성퇴적물인 Bunthang sequence의 절대 연대측정과 이의 고환경 및 지반운동에 대한 의미)

  • Seong, Yeong-Bae
    • Journal of the Korean Geographical Society
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    • v.42 no.2 s.119
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    • pp.165-176
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    • 2007
  • Absolute age of the deposition of 1.3 km-thick Bunthang sequence within the Skardu intermontane basin of the Central Karakoram was determined using radioactive decay of cosmogonic $^{10}Be$ and $^{26}Al$ burial dating. The Bunthang sequence deposited around 2.65 Ma, which is the oldest glaciation in the region. The timing of deposition of the Bunthang sequence is consistent with the previous suggestion that the basin filling took place between Brunhess and Matuyama chrons. Four major sedimentary facies interfinger within the Bunthang sequence: glacial diamict, lacustrine, fluvial and lacustrine facies upward. This sedimentary distinctiveness and the lack of evidence on the faults for alternative pull-apart basin model around the Bunthang sequence, suggest that the depressional basin was formed by deep subglacial erosion during the exrtensive Bunthang Glacial Stage and subsequently the sediments underlain by basal diamict, was quickly deposited by preglacial and paraglacial processes. Temporary ponding of the Indus River due to tectonic uplift in the downstream or blockage by mass movements might make the basin filing more possible. The hypothesis that the single ice sheet developed on the Tibetan Plateau during the global last glacial cycle should be refuted by the existence of the older extensive Bunthang glacier Furthermore, the extensive glaciation during the early Quaternary (and thus progressive decrease in extent with time) suggests that there may have been significant uplift of the Pamir to the west and Himalaya to the south, which would have reduced the penetration of westerlies and Indian summer monsoon and hence moisture supply to the region.

The Effect of Pore Structure of Zeolites on their Product Distribution and Deactivation in the Catalytic Cracking of n-Octane (n-옥탄의 촉매 분해반응에서 제올라이트의 세공구조가 생성물 분포와 활성저하에 미치는 영향)

  • Min, Byung Goo;Lee, Jae Youl;Song, Yo Soon;Seo, Gon
    • Korean Chemical Engineering Research
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    • v.45 no.6
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    • pp.547-553
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    • 2007
  • The catalytic cracking of n-octane over FER, MFI, MOR and BEA zeolites was studied by the protolytic cracking mechanism in order to understand the effect of pore structure of zeolites on their product composition and deactivation. The selectivities for $C_3$ and $C_3{^=}$ were high over the zeolites with medium pores due to additional cracking, while those for $C_4$ and $C_4{^=}$, the initial products, were high over the zeolites with large pores. MFI zeolite showed slow deactivation due to small carbon deposit, while FER zeolite with small pores deactivated rapidly with severe carbon deposit. The deactivation of BEA zeolite was slow even with a large amount of carbon deposit, but MOR zeolite showed a rapid deactivation even with a small amount of carbon deposit. The conversion measured along with the time on stream on these zeolite catalysts was simulated by a mechanism based on the simplified reaction path of n-octane cracking and the deactivation related to the pore blockage by carbon deposit.

Estimation of Road Capacity at Two-Lane Freeway Work Zones Considering the Rate of Heavy Vehicles (중차량 비에 따른 편도 2차로 고속도로 공사구간 도로 용량 추정)

  • Ko, Eunjeong;Kim, Hyungjoo;Park, Shin Hyoung;Jang, Kitae
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.19 no.2
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    • pp.48-61
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    • 2020
  • The objective of this study is to estimate traffic capacity based on the heavy-vehicle ratio in a two-lane freeway work zone where one lane is blocked by construction. For this, closed circuit television (CCTV) video data of the freeway work zone was collected, and the congestion at an upstream point was observed. The traffic volume at a downstream point was analyzed after a bottleneck was created by the blockage due to the upstream congestion. A distribution model was estimated using observed-time headway, and the road capacity was analyzed using a goodness-of-fit test. Through this process, the general capacity and an equation for capacity based on the heavy-vehicle ratio passing through the work zone were presented. Capacity was estimated to be 1,181~1,422 passenger cars per hour per lane (pcphpl) at Yeongdong, and 1,475~1,589pcphpl at Jungbu Naeryuk. As the ratio of heavy vehicles increased, capacity gradually decreased. These findings can contribute to the proper capacity estimation and efficient traffic operation and management for two-lane freeway work zones that block one lane due to a work zone.

An Experimental Study and Value Analysis for Performance Assessment of the Embo-thane Membrane Waterproofing Method (엘보탄도막방수공법의 성능평가를 위한실험적 연구 및 VE분석)

  • Yoon, Cha-Woong;Lee, Seung-Soo;Kim, Sang-Rok;Seo, Jong-Won
    • Korean Journal of Construction Engineering and Management
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    • v.10 no.5
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    • pp.123-134
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    • 2009
  • Since 1970s, urethane waterproofing method is broadly used in rooftops, underground spaces, and sports stadium for its outstanding ultraviolet blockage, watertightness, and elasticity. However, development of slippage-resistance and endurance, improvement of function considering convenience and visually pleasing of users, urethane waterproofing method is necessary, since rooftops and underground spaces have slippage and external force risks. Therefore, many improved waterproofing methods are being developed and, recently, embo-thane waterproofing method, which applies embo-spray coating system, has been developed. This paper explains exposure, nonexposure, and floor-material of embo-thane waterproofing method, and then perform experimental study for comparison with urethane waterproofing method about tensile strength, coefficient of expansion, performance of bond, anti-abrasion, and slippage-resistance. In addition, the performance index was presented for the superiority of embo-thane waterproofing method compared to urethane by setting up evaluation criteria considering not only physical performance but also design side of embo-thane waterproofing method, and Value Analysis applying AHP. Also for an assessment considering uncertain result, Monte Carlo Simulation Method was used to operate reliability analysis through statistic approach method.

Role of $K^+$ Channels in $H_2O_2$- and Cryo-induced Apoptosis of Mouse and Bovine Embryos (과산화수소와 동결에 의해 유도된 생쥐와 소 수정란의 사멸에 있어서 칼륨 통로의 역할)

  • Choe, Changyong;Kim, Chang-Woon;Kang, Dawon;Han, Jaehee
    • Journal of Embryo Transfer
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    • v.29 no.3
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    • pp.249-255
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    • 2014
  • Programmed cell death or apoptosis is associated with changes in $K^+$ concentration in many cell types. Recent studies have demonstrated that two-pore domain $K^+$ ($K_{2P}$) channels are involved in mouse embryonic development and apoptotic volume decrease of mammalian cells. In cerebellar granule neurons that normally undergo apoptosis during the early developmental stage, TASK-1 and TASK-3, members of $K_{2P}$ channels, were found to be critical for cell death. This study was performed to identify the role of $K^+$ channels in the $H_2O_2$-induced or cryo-induced cell death of mouse and bovine embryos. Mouse and bovine two-cell stage embryos (2-cells) exposed to $H_2O_2$ for 4 h suffered from apoptosis. The 2-cells showed positive TUNEL staining. Treatment with high concentration of KCl (25mM) inhibited $H_2O_2$-induced apoptosis of 2-cells by 19%. Cryo-induced death in bovine blastocysts showed positive TUNEL staining only in the cells near the plasma membrane. Cryoprotectant supplemented with 25 mM KCl reduced apoptosis slightly compared to cryoprotectant supplemented with 5 mM KCl. However, the combination of antioxidants (${\beta}$-mercaptoethanol) with 25 mM KCl significantly decreased the rate of $H_2O_2$-induced and cryo-induced apoptosis compared to treatments with only antioxidants or 25 mM KCl. These results show that blockage of $K^+$ channel efflux for a short-time reduces $H_2O_2$- and cryo-induced apoptosis in mouse and bovine embryos. Our findings suggest that apoptosis in mouse and bovine embryos might be controlled by modulation of $K^+$ channels which are highly expressed in a given cell type.

Efficient assay for respiration inhibitor using Saccharomyces cerevisiae (Saccharomyces cerevisiae를 이용한 효율적인 호흡저해제 검정법)

  • Choi, Gyung-Ja;Kim, Jin-Cheol;Kim, Heung-Tae;Cho, Kwang-Yun
    • The Korean Journal of Pesticide Science
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    • v.4 no.3
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    • pp.52-59
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    • 2000
  • A rapid assay to determine respiration inhibition of Saccharomyces cerevisiae by chemicals was developed. S. cerevisiae was harvested with two different liquid media, yeast extract-peptone-dextrose (YPD) medium capable of occurring both glucose fermentation and mitochondrial respiration, and non-fermentable carbon-yeast extract (NFY) medium capable of occurring respiration only Wells in 96-well plate were loaded with each cell suspension and various concentrations of 46 fungicides with various modes of action. n NFY medium, the non-fermentable carbon source, ethanol (NFY-E medium), glycerol (NFY-G medium) or lactate (NFY-L medium), was used. After incubation for $1{\sim}3$ days, minimum inhibitory concentrations (MICs) of the chemicals were recorded in the media. Of the 46 inhibitors employed in this study, four inhibitors of fungal respiration by blockage of electron flux in the mitochondrial respiratory chain, azoxystrobin, kresoxim-methyl, metominostrobin, and trifloxystrobin, exhibited strong antifungal activity in all of NFY media, but no activity in YPD medium. In contrast to this, five N-trihalomethylthio fungicides showed much stronger antifungal activities in YPD medium than three NFY media. Eleven fungicides inhibited growth of S. cerevisiae in all media and the other 26 fungicides showed no antifungal activity in all media. Thus, our rapid and efficient in vitro method can be considered as an alternative assay system for respiration inhibitor.

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Experimental Study for Establishment of Long-term Monitoring System using Fiber Optical Sensor for Pipeline System for Waste Transportation (광섬유센서를 이용한 쓰레기 이송관로의 장기 계측시스템 구축을 위한 실험적 연구)

  • Kim, Haeng-Bae;Song, Jae-Ho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.20 no.4
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    • pp.35-43
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    • 2016
  • Recently, the pipeline system for waste transportation has been increasingly constructed as new solution for the waste collection and disposal system by constantly increasing domestic waste which issued as social problem. The pipeline system is constructed through long distance, so proper long-term monitoring system is necessary which available to detect the damage location for the effective maintenance. In this paper, the experimental study is carried out to evaluate the applicability of optical strain gauge sensor based on FBG for the long-term monitoring system. Three test parameters such as pressure leaking, blockage and deformation are considered as typical damages for real-scale pipeline test specimen. In order to measure flexural and volumetric strain and temperature, three FBG sensors are installed at each monitoring sections. From the test results, this study suggested effective methods of sensor installation and arrangement. Also the sensor spacing for the design of monitoring system using FBG sensor is derived by the correlation of distances from deformation between sensor responses.

Effects of Stranded Oil on Seawater Infiltration in a Tidal flat Environment (조간대에 표착한 기름이 해수의 침투에 미치는 영향)

  • Cheong Jo, Cheong
    • Journal of Soil and Groundwater Environment
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    • v.8 no.1
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    • pp.75-80
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    • 2003
  • Understanding the seawater infiltration into tidal flat sediments is very important, because it is significantly correlated with the supply of dissolved oxygen, nutrients and organic matter to benthic organisms for survival. However oil blocks interstitial spaces of sediments, reduces seawater infiltration and results in the decrease in oxygen, nutrients and other food supply to benthic communities. The penetration depth of the stranded oil into the sediments is one of the most significant information to know the effect of spilled oil on biological communities and to set up a cleaning method. So we initiated this study to quantify the penetration behavior of spilled oil and to evaluate the influence of the penetrated oil on seawater infiltration in tidal flat environment and its ecological implications. The penetration depth of the crude oil into the tidal flat sediments was two times deeper than that of the fuel oil C, and the depth was significantly affected by stranded oil volume. However, the penetration depth of stranded oil was abruptly dropped at first falling tide but not significantly fluctuated after that. Moreover, hydrocarbon concentration showed the highest within the upper 2 cm. Seawater infiltration was decreased in proportion to the stranded oil volume. The seawater infiltration was more affected by the penetrated fuel oil C about 1.7 times than the crude oil, because the interstitial spaces of the top of sediments were more cleared by the fuel oil C. Therefore, quick cleaning actions for penetrated oil will be necessary for recovery of seawater infiltration because the seawater contains oxygen and nutrients necessary for the survival of benthic organisms in tidal flat.