• 폴리머
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• 제30권6호
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• pp.486-491
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• 2006

본 연구에서는 폐수중에 함유된 암모늄 이온을 전기투석 방법으로 회수하기 위하여 불균질 이온교환막을 압축성형 방법으로 제조하였다. 설폰화 양이온교환수지의 설폰화도는 설폰화제인 chlorosulfonic acid의 함량이 증가함에 따라 증가하였고, 최대 설폰화율은 10 vol%일때 3.32 meq/g이었다. 불균질 이온교환막의 인장강도와 신장률은 이온교환수지의 함량이 증가함에 따라 각각 감소하였으며 인장강도는 LLDPE 막이 가장 높게 나타났으며, 신장률의 경우 EVA 막이 가장 높게 나타났다. 불균질 이온교환막의 함수율은 이온교환수지의 함량이 증가함에 따라 증가하였으며 이온수송수는 PE 막의 경우 최대 0.973이었고, 전기저항값은 LLDPE막이 가장 낮게 나타났으며 수지의 함량 70 wt%일때 $10.36{\Omega}/cm^2$이었다.

• 분석과학
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• 제13권6호
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• pp.789-801
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• 2000

본 연구에서는 isotope dilution HRGC/HRMS 방법으로 저니토중의 PCDDs/PCDFs를 분석하였다. 분석결과 surrogate 표준물질의 평균 회수율은 70.1-80.8%로 양호하였다. 17종의 2, 3, 7, 8-치환이성체 분포에서는 OCDD가 총 농도의 40.6-78.5%를 나타내었으며, OCDF는 6.6-14.7%, 1, 2, 3, 4, 6, 7, 8-HpCDD는 5.1-7.7%를 나타내었다. 또한 PCDDS가 총 PCDDs/PCDFs중 62.4-86.9%를 나타내었다. TEQ 농도분포에서는 2, 3, 4, 7, 8-PeCDF가 22.7-35.6%를 나타내었다.

• 분석과학
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• 제14권5호
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• pp.422-431
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• 2001

염소표백공정을 포함하고 있는 펄프 제지폐수 배출시설의 폐수 중 다이옥신류의 배출특성을 파악하기 위해 표백공정 전 후단을 제외한 회수공정, 마감공정집수조 및 방류수의 알칼리 폐수를 채취 분석하였다. 회수공정과 마감공정에서 2,3,7,8-치환이성체의 배출분포는 2,3,7,8-사염화퓨란(TCDF) > 팔염화다이옥신(OCDD) > 팔염화퓨란(OCDF)의 순으로 배출되고 있으며, 퓨란류(PCDFs)와 다이옥신류(PCDDs)의 배출비는 76:24, 62:38로 조사되어 주로 퓨란류가 배출되고 있음을 알 수 잇었다. 그러나, 집수조에서는 팔염화다이옥신(OCDD) > 1,2,3,7,8-오염화다이옥신(PeCDD) > 1,2,3,4,7,8-육염화다이옥신(HxCDD)의 순으로 2,3,7,8-치환이성체가 배출되고 있으며, 독성등가환산농도로 환산한 결과 1,2,3,7,8-오염화다이옥신(PeCDD)이 81%, 1,2,3,4,7,8-육염화다이옥신(HxCDD)이 12%를 차지하는 것으로 나타났으며, 검출된 다이옥신류의 농도는 0.2266ng-TEQ/L로 조사되었다. 또한, 방류수에서의 2,3,7,8-치환이성체 배출분포는 팔염화다이옥신(OCDD) 및 2,3,7,8-사염화퓨란류(TCDF)의 순으로 배출되고 있으며, 독성등가환산농도의 배출분포는 1,2,3,7,8-오염화다이옥신(PeCDD) 및 2,3,7,8-사염화퓨란(TCDF)의 순으로 배출되었으며, 배출되는 다이옥신류의 농도는 0.377 ng-TEQ/L로 조사되었다.

• 한국산학기술학회논문지
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• 제22권4호
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• pp.56-66
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• 2021

본 연구에서는 가축분뇨 처리시설의 호기성 액비화 과정에서 발생하는 열을 회수하기 위한 폐열회수 시스템을 고안하여 시스템을 구성하는 요소 장치의 성능을 분석하였다. 또한, 회수된 열의 활용 가능성을 확인하였다. 실험 설정을 위해 가축분뇨 처리시설의 액비 발효조에서 발생하는 발효열을 확인하였다. 호기성 액비화를 위한 발효조의 온도가 균일성을 나타낸 특성과 34.5 ~ 43.9 ℃의 범위에서 운영되는 점을 고려하여 실험 온도 수준을 35, 40, 45 ℃로 설정하였다. PE 및 STS 파이프로 구성된 복합열교환기는 53.5, 65.6, 74.4 MJ/h 열에너지를 회수하고, 5 RT 용량의 히트펌프는 95.6, 96.1, 98.9 MJ/h 열에너지를 축열 하였으며, 이때 히트펌프의 난방성능계수는 4.53, 4.62, 4.65이었다. 발효조의 온도를 45 ℃로 가정한 열교환기의 최대 온수 생산능력을 급탕량 산정 방법으로 비교했을 때 56 360 kcal/day의 에너지 공급량을 확인하였다. 축열조와 연계된 FCU의 온풍 난방능력은 20.8 MJ/h, 에너지 이용효율은 96.1 %였다. FCU의 온풍으로 퇴비를 건조하였을 때 초기함수율 50.5 %에서 건조 후 함수율 45.8 %로 4.7 % 감소함을 확인할 수 있었다.

• 한국환경과학회지
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• 제19권12호
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• pp.1355-1359
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• 2010

The application of metal caps has been continuously increased as real life are extended. Metal caps is usually made of aluminum and polyethylene(PE) as packing. Since metal caps contain 75% aluminum on a weight basis, metal caps may be a valuable source when these were properly recovered. The recovery methods of metal caps have mechanical peeling and incineration. However these are either hard to apply in some case or environmentally unacceptable. So in this investigation, recovery method of aluminum from metal caps was investigated using pyrolysis. The result shows that pyrolysis temperature and pyrolysis time was $450^{\circ}C$ and 120min. respectively. Also 100% of aluminum was recovered from metal caps. Heat content of recovered oil was high enough to use as a fuel representing 7,425.0, 7,793.1, 7,583.2, 7,726.2(cal/g). Heavy metal contens in the oil were under regulatory limit indicating.

• Environmental Analysis Health and Toxicology
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• 제21권4호
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• pp.365-373
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• 2006

Emission of methyl bromide (MeBr) from soil was implicated in stratospheric ozone depletion. To determine multi analysis of alternatives fumigants for MeBr, this paper describes the methods of analysis in water and soil. The MeBr, methyl iodide (Mel), propargyl bromide (PBr), cis 1,3-dichloropropene (cis 1,3-D), trans 1,3-dichloropropene (trans 1,3-D) and chloropicrin(CP) are separated on the base line on GC-ECD at three column of AT+DB+DB (90m) with temperature programing of $35^{\circ}C{\rightarrow}110^{\circ}C$ on GC-ECD. The relative retention time for MeBr, Mel, PBr, cis 1,3-D, trans 1,3-D and CP is 1.0, 1.4, 2.3, 3.2, 3.6 and 3.7, respertively. The detection limit for MeBr, Mel, PBr, cis 1,3-D, trans 1,3-D and CP is 469 pg, 5 pg, 21 pg, 79 pg, 101 PE and 5pg, respectively. Recovery of MeBr Mel, PBr, cis 1,3-D, trans 1,3-D and CP in water added 150 ppm fumigants were 81%, 96%, 95%, 97%, 98% and 99%, respectively. Recovery of MeBr, MeI, PBr, cis 1, 3-D, trans 1,3-D and CP in soil added 150ppm fumigants were 56%, 84%), 85%, 81%, 87% and 88%, respectively.

• Journal of information and communication convergence engineering
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• 제2권1호
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• pp.9-14
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• 2004

In this paper the modeling of the RLP layer in CDMA2000 is presented, which uses the NAK based ARQ scheme for Random Error Channels. The RLP performs a partial link recovery through limited number of RLP frame transmission in case of frame error. In case when the RLP fails due to excessive frame error, the control is passed on to the higher (TCP) layer. The TCP layer provides the complete end-to-end recovery. Thus the reliable performance at the TCP/RLP is essential to maintain the required Quality of Service in the DS-CDMA wireless links. The modeling is done for the performance analysis of the system in terms of the throughput and the mean extra delays, which are calculated analytically and are compared with the results generated by the simulations. This paper studies the effect of the random errors over different types of RLP frame formats and also the performance of the NAK based ARQ mechanism used under these conditions. The simulation provides with the over all characteristics of the throughput and the mean extra delay in terms of realistic environment parameters like Eb/No and probability of packet error (PE), based on the channel conditions.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2021년도 학술발표회
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• pp.146-146
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• 2021

A contamination event occurring in water distribution networks (WDNs) needs to be handled with the appropriate mitigation strategy to protect public health safety and ensure water supply service continuation. Typically the mitigation phase consists of contaminant sensing, public warning, network inspection, and recovery. After the contaminant source has been detected and treated, contaminants still exist in the network, and the contaminated water should be flushed out. The recovery period is critical to remove any lingering contaminant in a rapid and non-detrimental manner. The contaminant flushing can be done in several ways. Conventionally, the opening of hydrants is applied to drain the contaminant out of the system. Relying on advanced information and communication technology (ICT) on WDN management, warning and information can be distributed fast through electronic media. Water utilities can inform their customers to participate in the contaminant flushing by opening and closing their house faucets to drain the contaminated water. The household draining strategy consists of determining sectors and timeslots of the WDN users based on hydraulic simulation. The number of sectors should be controlled to maintain sufficient pressure for faucet draining. The draining timeslot is determined through hydraulic simulation to identify the draining time required for each sector. The effectiveness of the strategy is evaluated using three measurements, such as Wasted Water (WW), Flushing Duration (FD), and Pipe Erosion (PE). The optimal draining strategy (i.e., group and timeslot allocation) in the WDN can be determined by minimizing the measures.

• The Korean Journal of Physiology and Pharmacology
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• 제2권3호
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• pp.307-312
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• 1998

This study was performed to investigate the mechanism of central analgesic effects of antidepressants. Thirty four male rats were anesthetized with pentobarbital sodium (40 mg/kg, ip). A stainless steel guide cannula and a PE tube (PE10) were implanted into the lateral ventricle and cisterna magna area. Stimulating and recording electrodes were implanted into the incisor pulp and anterior digastric muscle. Electrodes were led subcutaneously to the miniature cranial connector sealed on the top of the skull with acrylic resin. The jaw opening reflex was used in freely moving rats, and antidepressants were administered intracisternally in order to eliminate the effects of anesthetic agents on the pain assessment and evaluate the importance of the central action site of antidepressants. After 48 hours of recovery from surgery, digastric electromyogram (dEMG) of freely moving rats was recorded. Electrical shocks (200 ${\mu}sec$ duration, 0.5-2 mA intensity) were delivered at 0.5 Hz to the dental pulp every 2 minute. Intracisternal administration of $15\;{\mu}g$ imipramine suppressed dEMG elicited by noxious electrical stimulation in the tooth pulp to $76{\pm}6%$ control. Intracisternal administration of $30\;{\mu}g$ desipramine, nortriptyline, or imipramine suppressed dEMG remarkably to $48{\pm}2,\;27{\pm}8,\;or\;25{\pm}5%$ of the control, respectively. Naloxone, methysergide, and phentolamine blocked the suppression of dEMG produced by intracisternal antidepressants from $23{\pm}2\;to\;69{\pm}4%,\;from\;32{\pm}5\;to\;80{\pm}9%,\;and\;from\;24{\pm}6\;to\;77{\pm}5%$ of the control, respectively. These results indicate that antidepressants produce antinociception through central mechanisms in the orofacial area. Antinociception of intracisternal antidepressants seems to be mediated by an augmentation of descending pain inhibitory influences on nociceptive pathways.

• 공업화학
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• 제18권2호
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• pp.168-172
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• 2007

회분 병류 5단 평형추출에 의해 4종류의 질소고리화합물[indole(In), quinoline(Q), iso-quinoline(iQ), quinaldine(Qu)], 3종류의 2환 방향족화합물[1-methylnaphthalene(1MN), 2-methylnaphthalene(2MN), dimethyl naphthalene(DMN)], biphenyl과 phenyl ether로 구성된 모델 혼합물로부터 In의 분리를 검토했다. 본 연구의 원료로서 사용된 모델 혼합물은 콜타르 유분(유출온도범위: $240{\sim}265^{\circ}C$)을 구성하고 있는 성분 및 조성을 고려하여 작성했다. 추출용매로서는 Formamide 수용액을 사용했다. 4단 평형추출을 통해 In을 99% 이상 회수할 수 있었다. 5단 평형추출을 통해 얻어진 DMN을 기준성분으로한 In의 선택도는 63~118의 범위를 나타냈다. 본 연구를 통해 얻어진 실험적 결과와 이전의 연구결과를 이용하여 콜타르 중에 함유된 In의 분리 및 회수공정을 검토했다.