• 제목/요약/키워드: Branch system

검색결과 1,333건 처리시간 0.025초

Performance evaluation of membrane bioreactor (MBR) coupled with activated carbon on tannery wastewater treatment

  • Alighardashi, Abolghasem;Pakan, Mahyar;Jamshidi, Shervin;Shariati, Farshid Pajoum
    • Membrane and Water Treatment
    • /
    • 제8권6호
    • /
    • pp.517-528
    • /
    • 2017
  • This study evaluates the performance of membrane bioreactor (MBR) coupled with a modified walnut shell granular activated carbon (WSGAC) for tannery wastewater treatment. For this purpose, a pilot with overall volume of 80L and 12 hours hydraulic retention time (HRT) is operated in three scenarios. Here, the chemical oxidation demand (COD) of wastewater is reduced more than 98% in both C:N ratios of 13 (S1) and 6.5 (S2). This performance also remains intact when alkalinity depletes and pH reduces below 6 (S3). The ammonium removal ranges between 99% (S2) and 70% (S3). The reliability of system in different operating conditions is due to high solids retention time and larger flocs formation in MBR. The average breakthrough periods of WSGAC are determined between 15 minutes (S2) and 25 minutes (S1). In this period, the overall nitrate removal of MBR-WSGAC exceeds 95%. It is also realized that adding no chemicals for alkalinity stabilization and consequently pH reduction of MBR effluent (S3) can slightly lengthen the breakthrough from 15 to 20 minutes. Consequently, MBR can successfully remove the organic content of tannery wastewater even in adverse operational conditions and provide proper influent for WSGAC.

사출 금형의 병렬 냉각 채널 설계 방법 (DESIGN OF PARALLEL COOLING CHANNELS IN A PLASTIC INJECTION MOLD)

  • 김현수;정휘권;한병윤;김영만;박형구
    • 한국전산유체공학회지
    • /
    • 제17권3호
    • /
    • pp.93-98
    • /
    • 2012
  • The injection molding process is suitable for manufacturing complicated plastic products. As the customer request higher quality products increase, realization of the precise dimensional and shape controls is getting more important. For this purpose it is important to obtain uniform cooling procedure over the whole surface of the high temperature molded plastic. Failure to this may lead to different shrinkage speed, internal stresses and unwanted shape deformations. It is necessary to distribute coolant flow rates to the main channel and to the sub-channels properly to insure uniform cooling process when there are parallel cooling channels. In this study, three-dimensional turbulent flow simulations for representative parallel cooling channels were performed. To insure the intended flow rate to each sub-channels, various shape designs for the channel system were investigated. The results show that as the Reynolds number increases the effect of shape design is more profound. Through the proper flow distribution, uniform cooling effects would be expected.

Familial Mediterranean fever presenting as fever of unknown origin in Korea

  • Lee, Jun Hee;Kim, Jong Hyun;Shim, Jung Ok;Lee, Kwang Chul;Lee, Joo Won;Lee, Jung Hwa;Chae, Jae Jin
    • Clinical and Experimental Pediatrics
    • /
    • 제59권sup1호
    • /
    • pp.53-56
    • /
    • 2016
  • Familial Mediterranean fever (FMF) is the most common Mendelian autoinflammatory disease, characterized by uncontrolled activation of the innate immune system that manifests as recurrent brief fever and polyserositis (e.g., peritonitis, pleuritic, and arthritis). FMF is caused by autosomal recessive mutations of the Mediterranean fever gene, MEFV which encodes the pyrin protein. Although FMF predominantly affects people from Mediterranean and Middle Eastern ethnic origins, 3 cases of FMF have been reported in Korea since 2012. We report another case of FMF in Korea in which the patient presented with a month-long fever without serositis. After treatment with colchicine was initiated, the patient's symptoms quickly subsided. The response to colchicine was helpful for diagnosis. We compare the FMF genotypes in Korea with in other countries. Studying FMF cases in Korea will help establish the best MEFV exons to use for screening and diagnosis of Korean FMF.

Spatial Distribution of Urination by Cattle in a Daytime Grazing System

  • Hirata, M.;Higashiyama, M.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제10권5호
    • /
    • pp.484-490
    • /
    • 1997
  • Spatial distribution of urination by Japanese Black heifers and steers was investigated, and compared with the distribution of defecation. The animals grazed a bahiagrass (Paspalum notatum $Fl\ddot{u}gge$) pasture in the daytime, and spent the rest of the day in a barn. The distribution of urination to the pasture was greater than that expected from the proportion of time that the animals spent in the pasture. Correspondingly, the distribution was smaller in the barn. Such a distribution pattern of urination to the pasture and barn was similar to that of defecation, and affected by the intake of supplement on the previous day. The distribution of urination within the pasture, i.e. the distribution to the paddock, alley and resting area, was often uneven on an area basis. The animals often urinated sparsely in the alley and resting area, while they urinated in the paddock almost proportionally to its area. This was a clear contrast to the distribution pattern of defecation, which was sparse in the paddock and dense in the resting area. The degree of aggregation of urination in the paddock, alley and resting area varied with the meteorological factors and the intake of supplement.

일본 대덕사의 용원완정원의 조직성에 관한 연구 (A Study on the Organization of Ryu Gen in at Aai Toku Ji temple in Japan.)

  • 안계복
    • 한국조경학회지
    • /
    • 제24권3호
    • /
    • pp.5-13
    • /
    • 1996
  • This study is about to prove one factor among many ones that contribute to the formation of the Japanese Garden's pattren. It is believed by this study that distinguished Japanese Garden's pattren are made possible by an organized ability of the japaneses traditional landscape artists who had ability to develope a diversified forms of applications within the organized framework. To verify this assumption, the study has chosen Ryu Gen In, temple garden that is considered to determine the pattren of Japanese Garden best with a new concept ; Organization. The results of this analysis show as follows : 1. Ryu Gen In, consists of a series of building and five-small gardens, is largely organized by the union of two geometric formations : concave and convex. Each garden as a sub-organization is further organixed with a series of tree-branch typed structure. 2. The five-small gardens are formed jinto a whole system by connecting each one with floor. This connection makes a timely organization. 3. Each small garden is further organized alloted roles, namely, depends upon whether they play a major or minor role. 4. It is believed that sands and moss play a cotrolling role to conbine the elements into one within each unit of small garden. 5. It is found that figured sands, moss, sands and moss, or shrubs are used as means of organization to connect the small group elements within each small gardens. 6. It is considered that buildings and mud-walls are used as means of separation between Ryu Gen In and an outer world, and betwen small gardens.

  • PDF

외부의 물과 Er:YAG Laser의 작용에 의한 Dental Hard Tissue에서의 열과 역학적 효과: Free-running 방식 (Exogenous-Water-Induced Thermal and Mechanical Effects on Dental Hard Tissue by the Er:YAG Laser: Free-running Mode)

  • 권용훈
    • 대한의용생체공학회:학술대회논문집
    • /
    • 대한의용생체공학회 1997년도 추계학술대회
    • /
    • pp.380-384
    • /
    • 1997
  • This study was performed to understand the exogenous-water-drop induced thermomechanical effect on the tooth in the free-running Er:YAG laser mode for the proper use of water as a laser energy absorber and coolant in dentistry. The ree-running Er:YAG laser was used in the dental hard tissue ablation study. A Microjet system was employed to dispense precise water drops. Ablation rate, recoil momentum, and temperature rise in the pulp cavity were measured with and without an exogenous water drop on the tooth surface. Exogenous water enhanced ablation rate in the thick tooth in which the ablation rate on the dry surface does not increase linearly but shows plateau. Optimal exogenous water volume was shifted from 2 nl to 4 nl as the laser energy was increased from 48 mJ to 145 mJ. The magnitude of the recoil momentum was increased as the volume of exogenous water increased. The results of this study suggest that we must pay attention to the recoil momentum or recoil pressure study or the optimal and safe usage of water in the dental treatment because these mechanical effects depend on the volume of exogenous water on the tooth surface.

  • PDF

이천 태양전파 분광시스템 및 운용 소프트웨어 개발 (ICHON SOLAR RADIO SPECTROGRAPHIC SYSTEM AND DEVELOPMENT OF ITS OPERATION SOFTWARE)

  • 조경석;이근호;김갑성
    • Journal of Astronomy and Space Sciences
    • /
    • 제14권2호
    • /
    • pp.320-329
    • /
    • 1997
  • 전파연구소 이천 분소에는 각각 세 개의 안테나로 30MHz∼2500MHz 대역의 태양전파를 관측할 수 있는 광대 역 태양전파분광시스템이 1995년에 설치되었다. 그 동안 태양전파 데이터를 수집 분석할 수 있는 소프트웨어가 없어 실질적인 관측이 이루어지지 않았으나 본 연구에 의해 운용 소프트웨어가 개발됨으로써 본격적인 태양전파관측 연구를 수행할 수 있게 되었다. 개발된 운용 소프트웨어를 실험 이용한 결과 1997년 11월 4일 06시경(UT)에 연속하여 발생한 3개의 TYPE III Burst에 대한 양질의 관측자료를 얻을 수 있었다. 본 논문에서는 전파연구소 이천 분소의 광대역 전파분광시스템을 소개하고 태양전파 데이터의 취득, 처리 및 분석을 위해 개발한 소프트웨어와 이를 통해 관측된 결과에 대하여 설명한다.

  • PDF

직접 검파 펄스 위치 변조 광통신 채널에서의 터보 부호의 성능 (Performance of Turbo Codes in the Direct Detection Optical PPM Channel)

  • 이항원;이상민
    • 한국통신학회논문지
    • /
    • 제28권6C호
    • /
    • pp.570-579
    • /
    • 2003
  • 본 논문에서는 펄스 위치 변조를 사용하는 직접 검파 광통신 채널에서의 터보부호의 성능에 대하여 연구한다. 직접 검파기로서는 이상적인 광자 계수기를 사용하는 경우를 가정하며, 채널 잡음으로는 양자 잡음뿐 만 아니라 배경 잡음도 있는 경우를 가정한다. 즉 사용된 채널 모델은 M-ary PPM Poisson 채널이다. 이 채널에 터보 부호를 적용하기 위한 송수신기의 구조를 제시하고, 또한 제안된 터보 부호화 시스템을 위한 터보 복호 알고리즘을 유도한다. 복호 알고리즘의 유도는 기존의 AWGN 채널을 위한 터보 복호 알고리즘에서 가지 메트릭 연산 부분을 수정함으로써 얻어진다. 이론적인 비트 에러 확률 상한 값의 유도 및 컴퓨터 시뮬레이션의 실행을 통하여, 제안된 터보 부호화 방식의 성능을 분석하고 그 결과를 Reed-Solomon 부호 및 길쌈 부호의 성능과 비교한다.

닭에 집단 발병한 뮤코마이코시스 (Mucormycosis in a group of chickens)

  • 정기수;임병무
    • 대한수의학회지
    • /
    • 제29권1호
    • /
    • pp.75-79
    • /
    • 1989
  • Mucormycosis는 자연 환경속에 상채하고 있는 Mucorales 목의 곰팡이류에 의해 발생하는 질병인데, 강원도 속초시의 한 양계장에서 82수(연령 100일~2년)의 닭에 집한 발병하였다. 임상중상은 식욕감퇴, 하리, 영양실조, 호흡곤란, 마비 등으로 발병 후 수 주간에 폐사하였으며, 부검시 호흡기관을 비롯하여 간장, 심장, 비장, 신장, 소화관 등에서 회황색의 다발성 결절(0.14~4.6cm)과 소출혈반점을 발견하였다. 병리 조직학적으로 병소는 화농성 혹은 건락성 괴사소와 이를 둘려싸는 위산성 백혈구, 대식세포, 임파구, 거대핵세포의 침륜 등 급성 육아종성염증 소견을 나타내었으며, 본균 특이성의 균사(두께 $4{\sim}24{\mu}$)를 괴사병소 내에서 관찰하였다. 본 질병의 발생은 사료 첨가제와 치료제로써 항생제의 남용이나 타질병의 일차 감염 등이 전소인으로 작용하는 것으로 사료된다.

  • PDF

비 지질 산화손상에 대한 어성초 뿌리의 항산화 효과 (Antioxidative effects of Houttuynia cordata root on non-lipid oxidative damage)

  • 하대식;김충희;김의경;강정부;김종수
    • 대한수의학회지
    • /
    • 제47권1호
    • /
    • pp.25-32
    • /
    • 2007
  • Houttuynia cordata root on non-lipid oxidative damage. The antioxidative efects of methanolic (MeOH) extract of Houttuynia cordata rooton non-lipid, including liposome oxidation, oxidation of deoxyribose, protein oxidation, chelating, scavenging,and 2'-deoxyguanosine (2'dG) oxidation were investigated. Houttuynia cordata root exhibited highantioxidative effect in a liposome model system. The inhibitory effect of MeOH extract on deoxyribosedamage exhibited antioxidative effect and it afforded considerable protection against damage to deoxyribose.In addition, MeOH extract at over 300extracts exhibited metal binding ability for hydrogen peroxide. Furthermore, the oxidation of 2'dG to 8-hydroxy-2-deoxyguanosine was inhibited by MeOH extracts, and scavenging activity for hydroxyl radicalexhibited a remarkable effect. The present results on biological model systems showed that MeOH extractswas effective in the protection of non-lipids against various oxidative model systems.