• 제목/요약/키워드: Cavity Wall

검색결과 546건 처리시간 0.024초

서해안 양식 넙치에서 Neoheterobothrium 감염증의 발생 및 치료 (Occurrence and elimination of Neoheterobothrium infection from cultured oliver flounder (Paralichthys olivaceus) in the western coast of Korea)

  • 장환;문진산;김지연;조성준;손성완
    • 대한수의학회지
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    • 제47권3호
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    • pp.299-302
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    • 2007
  • Neoheterobothrium hirame (N. hirame) is a large blood-feed gill-worm infecting the highly prized olive flounder. The present study was reported the occurrence and elimination of Neoheterobothrium infection from young cultured oliver flounder in the western coast of Korea. Flounder (weight 18-25 g, length 10-15 cm) were obtained from a cultured farm at Taean of Korea at May 2006. A lot of flounder died with serious anemia. We isolated N. hirame from the buccal cavity wall of dead flounder. Adult parasites were 5-15 mm in total length, with 4 pairs of clamps on the pedunculated haptor and isthmus region embedded in host tissue, while immature and sub-adults were identified the attachment to the gill filaments, rakers and arches with the clamps. All fish with infection were treated with 8% NaCl-supplemented seawater for 1 and 10 min at $22^{\circ}C$, respectively. The significant reduction in mortality (6.7%) was observed among fish treated with 8% salt water for 10 minutes, when compared with that of non-treatment group (100%).

ENHANCED BIOAVAILABILITY OF NIFEDIPINE USING COATED DRY ELIXIR

  • Park, Jae-Yoon;Kim, Chong-Kook
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1996년도 춘계학술대회
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    • pp.282-282
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    • 1996
  • The purpose of this study was to prepare the nifedipine dry elixir (NDE) and coated nifedipine dry elixir (CNDE) containing nifedipine ethanol solution for improving the dissolution rate and bioavailability of nifedipine. NDE containing nifedipine and ethanol in wall materials of dextrin was prepared using a spray-dryer and then NDE was coated with eudragit acrylic resin to make CNDE. Shape and size of the NDE and CNDE were monitored by scanning electron micrograph and laser particle size analyzer In vitro dissolution tests were performed in simulated gastric and intestinal fluid. Bioavailability of NDE and CNDE were compared with drug powder suspension and commercial soft capsule after oral administration of the preparations to rats. NDE and CNDE are spherical in shape. Cross-sectional view of dry elixirs indicates the large inter cavity containing ethanolic drug solution in shell. Geometric mean diameter of NDE and CNDE is about 6.64 and 8.70 $\mu\textrm{m}$, respectively. Drug dissolution rate within first 5 min from NDE increased dramatically irrespective of dissolution medium. However, CNDE showed a particularly retarded dissolution rate in pH 1.2 simulated gastric fluid compared with NDE. The bioavailability of nifedipine in the NDE was increased dramatically compared with drug powder suspension. CNDE reduced initial burst-out plasma peak compared with NDE. CNDE as a sustained release delivery system could reduce the initial burst-out plasma peak due to controlling the release rate of nifedipine from NDE and maintain the effective plasma level over a longer period within therapeutic window with enhanced bioavailability of nifedipine.

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스캐닝 프로브를 이용한 미지의 자유곡면 점군 획득에 관한 연구 (Digitization of Unknown Sculptured Surface Using a Scanning Probe)

  • 권기복;김재현;이정근;박정환;고태조
    • 한국정밀공학회지
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    • 제21권4호
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    • pp.57-63
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    • 2004
  • This paper describes a method for digitizing the compound surfaces which are comprised of several unknown feature shapes such as base surface, and draft wall. From the reverse engineering's point of view, the main step is to digitize or gather three-dimensional points on an object rapidly and precisely. As well known, the non-contact digitizing apparatus using a laser or structured light can rapidly obtain a great bulk of digitized points, while the touch or scanning probe gives higher accuracy by directly contacting its stylus onto the part surface. By combining those two methods, unknown features can be digitized efficiently. The paper proposes a digitizing methodology using the approximated surface model obtained from laser-scanned data, followed by the use of a scanning probe. Each surface boundary curve and the confining area is investigated to select the most suitable digitizing path topology, which is similar to generating NC tool-paths. The methodology was tested with a simple physical model whose shape is comprised of a base surface, draft walls and cavity volumes.

고온용 히트파이프형 태양열 흡수기 (High-Temperature Heat-Pipe Type Solar Thermal Receiver)

  • 부준홍;정의국
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2007년도 춘계학술대회
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    • pp.668-671
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    • 2007
  • A numerical study was conducted on a simplified model of a high-temperature solar receiver which incorporates liquid-metal heat pipe. The objective of this paper is to compare the isothermal characteristics of the heat pipe receiver with the conventional receiver utilizing convection of molten salt as heat carrier. The solar receiver was assumed to be subject to a concentration ratio between 50 and 1,000 to supply high-temperature heat to a stirling engine for electric power generation. For simplicity of the analysis, a cylindrical geometry was assumed and typical dimensions were used based on available literature. The heat pipe had a shape of double-walled cavity and the working fluid was a sodium. The analysis was performed assuming that the radiation heat flux on the inner walls of the receiver was uniform, since the focus of this study was laid on the comparison of the conventional type and heat pipe type receiver. The results showed that the heat pipe type exhibited superior performance when the operating temperature becomes higher. In addition, to explore the advantage of the heat pipe receiver, the channel shape and dimensions should be adjusted to increase the heat transfer area between the wall and the heat trnasfer medium.

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높은 음압에서의 내부 확장관형 음향 공명기의 설계를 위한 실험적 음향 임피던스 모델 (An Empirical Acoustic Impedance Model for the Design of Acoustic Resonator with Extended Neck at a High Pressure Environment)

  • 박순홍;서상현
    • 한국소음진동공학회논문집
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    • 제22권12호
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    • pp.1199-1205
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    • 2012
  • An empirical acoustic impedance model of acoustic resonators with extended neck at a high sound pressure environment is proposed. The acoustic resonator with extended neck into its cavity is appropriate for the launcher fairing application because the length of neck does not increase the total height of the resonator. This enables one to design slim and light acoustic resonators for launch vehicles. The suggested acoustic impedance model considers the incident pressure and geometric variables(the neck length, the perforation ratio and the hole diameter) in terms of non-dimensional variables. Several acoustic resonators with extended neck are manufactured and their wall impedances are measured according to the pre-defined incident pressure levels. Effects of non-dimensional variables on the non-linear acoustic impedance are investigated so that a simple non-linear impedance model for the launcher fairing application can be proposed. It is demonstrated that the estimated acoustic resistance and acoustic length correction show reasonable agreement with the measured ones within the range of design parameters for launcher fairings.

Computational Study of the Mixed Cooling Effects on the In-Vessel Retention of a Molten Pool in a Nuclear Reactor

  • Kim, Byung-Seok;Ahn, Kwang-Il;Sohn, Chang-Hyun
    • Journal of Mechanical Science and Technology
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    • 제18권6호
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    • pp.990-1001
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    • 2004
  • The retention of a molten pool vessel cooled by internal vessel reflooding and/or external vessel reactor cavity flooding has been considered as one of severe accident management strategies. The present numerical study investigates the effect of both internal and external vessel mixed cooling on an internally heated molten pool. The molten pool is confined in a hemispherical vessel with reference to the thermal behavior of the vessel wall. In this study, our numerical model used a scaled-down reactor vessel of a KSNP (Korea Standard Nuclear Power) reactor design of 1000 MWe (a Pressurized Water Reactor with a large and dry containment). Well-known temperature-dependent boiling heat transfer curves are applied to the internal and external vessel cooling boundaries. Radiative heat transfer has been considered in the case of dry internal vessel boundary condition. Computational results show that the external cooling vessel boundary conditions have better effectiveness than internal vessel cooling in the retention of the melt pool vessel failure.

식도중복증의 1례 (Duplication of the Esophagus -Report of A Case-)

  • 홍기우
    • Journal of Chest Surgery
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    • 제7권2호
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    • pp.169-174
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    • 1974
  • Duplication of the alimentary tract, especially of the esophagus, have been regarded as rare cong- enital anomalies. However, they are being reported with increasing frequency in the literature. In the . ,- past they have been described by a variety of names, such as "enteric cysts", "intestinal cysts", "giant diverticula", "`mediastinal cysts of foregut origin" "enterogenous cysts" and other descriptive terms. . Most authorities now agree that these anomalies are best described by the term "duplications of the alimentary tract. The duplications [of the alimentary tract] are spherical or tubular structures which poses a well developed smooth muscle layer and are lined with a mucous membrane from any part of the alimentary tract. They may occur at any place in the digestive tube from the tongue to the rectum and usually are intimately attached to some portion of the alimentary tube. We have experienced a duplication of the esophagus in 14 years old middle schoolboy. He complained dysphagia, eructation and substernal pain associated with intermittent high fever and chilliness, increasing in severity for recent three weeks. Routine chest X-ray film revealed nore markable abnormal finding but esophagogram. revealed marked narrowing of the esophagus throughout with a large blind pouch in lower half with fistulous communication at mid portion of the esophagus. On thoracotomy, a large infected blind pouch communicating with the lumen of normal esophagus proximally, Was extended from the level of 5th to 10th thoracic spine. The duplicated segment of the esophagus has a common muscular .wall and proximal communication with the adjacent esophagus. The infected, duplicated esophagus was segmentally resected, and esophagogastrostomy with pyloroplasty was done by displacing the stomach into the right thoracic cavity through midline laparotomy. His Postoperative course was uneventful and discharged without complication.

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Laparoscopic Transabdominal Transfer of Blastocysts in Korean Black Goats

  • Cho, Sang-Cheol;Cho, Jong-Ki;Shin, Sang Tae
    • 한국수정란이식학회지
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    • 제32권2호
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    • pp.47-52
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    • 2017
  • As a part of the effort to improve post-transfer survival rate of embryos in Korean black goats, a technique for laparoscopic uterine transfer of blastocysts was carried out. A total of 26 transferrable embryos (morula to expanded blastocysts) were transferred to 13 recipient goats via transabdominal laparoscopic method. In consequence of our hormone protocol, 65% of the recipients (13/20) were found to have synchronized estrus. After confirmation of corpus luteum in each recipient goat, a Babcock laparoscopic forceps was inserted into the lower abdominal cavity to hold a uterine horn and fasten it near the peritoneum without causing injury. Then 7.5cm long 16G IV catheter was inserted directly into the uterine lumen through the abdominal wall. After removal of the stylet of the IV catheter, the embryo transfer tube (identical in size to the stylet and loaded with blastocysts) was inserted into the uterine lumen through the catheter to unload the embryos. Of the 13 estrus synchronized recipients, 9 were transferred blastocysts and 4 were transferred molurae (2 embryos in each recipient) in uterine ipsilateral to the ovary with corpus luteum. Four of the 9 recipients which blastocysts were transferred using this method has been confirmed pregnant (44.4% pregnancy rate).

Substitutions for Cys-472 and His-509 at the Active Site of $\beta$-Galactosidase from Lactococcus lactis ssp. lactis 7962 Cause Large Decreases in Enzyme Activity

  • Chung Hye-Young;Yang Eun-Ju;Chang Hae-Choon
    • Journal of Microbiology and Biotechnology
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    • 제16권8호
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    • pp.1325-1329
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    • 2006
  • Structural modeling of $\beta$-galactosidase from L. lactis ssp. lactis 7962 has shown that the residues Cys-472 and His-509 are located in the wall of the active-site cavity. To examine the functions of Cys-472 and His-509, we generated five site-specific mutants: Cys-472-Ser, Cys-472-Thr, Cys-472-Met, His-509-Asn, and His-509-Phe. $\beta$-Galactosidase substituted at Cys-472 with Met or His-509 with Phe had <3% of the activity of the native enzyme when assayed using ONPG as substrate. The other mutants Cys-472-Ser, Cys-472-Thr, and His-509-Asn had ca. 10-15% of the native enzyme activity. The V$_max$ values of the five mutated enzymes were lower (60-7,000-fold) than that of native enzyme. These results show that the catalytic ability of $\beta$-galactosidase is significantly affected by mutations at Cys-472 or His-509.

슬롯방향 변화에 따른 충격파 간섭유동 특성변화에 관한 연구 (Variation of the Characteristics of Shock-Interaction Flows for Different Slot-Directions)

  • 장성하;이용희;이열
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2006년도 제26회 춘계학술대회논문집
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    • pp.306-309
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    • 2006
  • 슬롯을 이용한 충격파와 난류 경계층의 간섭유동의 피동제어에 관한 연구가 이루어졌다. 슬롯의 다양한 형상 변화가 간섭유동에 미치는 영향이 관찰되었으며, 이를 위하여 간섭유동 후방에서 피토/벽압력 분포 및 쉴리렌, 오일막 간섭 줄무늬 형상과 같은 유동가시화 정보 등이 얻어졌다. 특정한 슬롯적용의 경우, 충격파를 통한 전압손실의 감소가 관찰되었으나 경계층의 두께는 두꺼워지는 것으로 나타났다.

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