• 제목/요약/키워드: Non-mass enhancement

검색결과 69건 처리시간 0.036초

계면활성제 첨가시 수평 냉각관 외부를 흘러내리는 LiBr수용액의 열 및 물질전달 특성에 관한 연구 (A Study on Heat and Mass Transfer Characteristics of LiBr-$H_2$O Solution with a Sufactant Flowing over a Cooled Horizontal Tube)

  • 김경희;설신수;이상용
    • 설비공학논문집
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    • 제14권4호
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    • pp.341-349
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    • 2002
  • Heat and mass transfer characteristics of a surfactant-added LiBr-$H_2O$ solution flowing over a single horizontal tube were examined experimentally. The parameters considered were surfactant (2-ethyl-1-hexanol) concentration, solution temperature at the top of the tube and absorber pressure. Even with an amount of the surfactant below the solubility limit, heat and mass transfer performances were enhanced tremendously. The Nusselt and Sherwood numbers increased by about 70% and 340%, respectively, when 10 ppm of the surfactant was added. However, an excess amount of the surfactant in the solution did not bring a further enhancement. The absorption performance deteriorated when the non-condensable gases were extracted from the system (by a vacuum pump) since the vaporized surfactant was also extracted during the process. Therefore, it is desirable to add a sufficient amount of the surfactant (more than 10 ppm) to maintain high performance of absorption.

중안면부에 발생한 염증성 가종양 (Inflammatory pseudotumor of the midfacial area)

  • 안현숙;최선영;고광준
    • Imaging Science in Dentistry
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    • 제31권2호
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    • pp.121-127
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    • 2001
  • Inflammatory pseudotumor was originally described in the lung, but recently has been recognized to occur in various sites. A 56-year-old female was referred to our department with a painless swelling of the right midfacial area since 3 months ago. Clinical examination showed non-specific intraoral findings, but asymmetric facial appearance and numbness of the right midfacial area. Plain radiographs and CT images showed aggressive destruction and irregular thickening of the right maxillary sinus wall, increased antral opacification, and destruction of the zygomatic arch. A relatively well-defined soft tissue mass occupied the right maxillary sinus, nasal cavity, zygoma, and infraorbital region. The soft tissue mass showed mild enhancement on CT. Radiographically, this lesion presented a rapidly enlarging mass demonstrating aggressive behavior, mimicking a malignant tumor. Histopathologic examinations showed plasma cells and inflammatory cells in variable fibrotic tissues and demonstrated positive reactivity for vimentin. No malignent changes could be found.

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Population Inquiry Regarding Mammography in Postmenopausal Women in Southern Brazil

  • Romeiro-Lopes, Tiara Cristina;Dell'Agnolo, Catia Millene;Rocha-Brischiliari, Sheila Cristina;Gravena, Angela Andreia Franca;de Barros Carvalho, Maria Dalva;Pelloso, Sandra Marisa
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권11호
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    • pp.6839-6844
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    • 2013
  • This study was conducted to analyze the prevalence of non-performance of mammography, and associated factors, among postmenopausal women. This analytical, exploratory, cross-sectional study, of a domicile population inquiry type, was performed in the municipality of Maringa, Parana, Brazil. A total of 456 women were interviewed, aged 45 to 69 years, who presented with natural menopause and cessation of menstruation for at least twelve months. Statistical associations were found between the non-performance of mammography and schooling of less than seven years, paid employment, sedentary lifestyle, smoking, the non-use of hormone replacement therapy, not having consulted a doctor in the previous year, not having consulted a gynecologist, lacking a family history of breast cancer, not having performed the Papanicolaou test, not having performed clinical breast examination, and not having difficult access to health services. After logistic regression analysis, not performing mammography was associated with reports of a fair or bad health status. The study data revealed factors "responsible" for the non-performance of mammography, and the results should contributing to improvement/enhancement of healthy behaviour of Brazilian women in the post-menopausal phase.

유방에 발생한 일차성 비호지킨림프종의 자기공명 분광법 및 확산강조 영상: 2예 (MR Spectroscopy and Diffusion Weighted Imaging Findings of Primary Non-Hodgkin Lymphoma of the Breast: Two Case Reports)

  • 남상유;유은영;최혜영
    • Investigative Magnetic Resonance Imaging
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    • 제18권2호
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    • pp.176-181
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    • 2014
  • 유방의 일차성 비호지킨림프종은 드문 종양으로 유방촬영술과 초음파에서 다양한 영상소견을 보인다. 하지만 자기공명영상소견은 여러개의 증례로만 보고되어 있고, 자기공명분광법과 확산강조영상에 대한 보고는 거의 없다. 저자들은 유방의 일차성 비호지킨림프종을 진단받은 두명의 여자환자의 증례를 기본 자기공명영상에 더하여 자기공명 분광법 및 확산강조 영상소견과 함께 보고하고자 한다. 종양은 유방촬영술과 초음파에서 경계가 좋은 종괴로 나타났으며, 조영증강자기공명영상에서 강한 조영증강을 보였다. 또한 다른 악성종양에서 나타나는 것과 같이 확산강조영상에서는 확산제한을 보이고, 자기공명분광법에서는 콜린값이 증가하는 소견을 보였다.

선발과 비선발 참돔 (Pagrus maior) 계통의 성장 양상 비교 (Comparative Growth Performance of the Selected and the Non-selected Red Sea Bream (Pagrus major) Lines)

  • 노충환;홍경표;오승용;최희정;박용주;명정구;김종만
    • 한국수산과학회지
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    • 제37권5호
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    • pp.400-404
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    • 2004
  • Growth performances of the selected and the non-selected red sea bream (Pagrus major) lines were evaluated up to marketable size. The offspring were mass-produced either from the selected line (the fourth generation of broods from mass selection) or the non-selected line (the second generation of wild broods). Early (59 to 103 days old, trial I) and late growth performances (4 to 24 months old, trial II) were evaluated based on communal rearing in land-based tanks and sea cages, respectively. In trial I, the selected line exhibited significantly higher values in both weight gain (WG) and specific growth rate (SGR) when compared to those observed in the non-selected line (P<0.05). In trial II comprising of three growth phases (4-9, 9-16 and 16-24 months old), selected line showed only slightly improved in WG and SGR at the beginning two growth phases (4-9 and 9-16 months old) (P>0.05), however, displayed significantly higher values at the last growth phase (16-24 months old) (P<0.05). Overall WG and SGR throughout the experiment (4-24 months) were also significantly higher in the selected line than the non-selected line (P<0.05). Consequently, mean body weight of the selected line at 24 months old was 1.4-fold (40.8{\%}\;increased) as compared to that of the non-selected line. This present result indicates that mass selection of this species against the growth traits might be quite effective, and the present advance has important Implication in the productivity enhancement of red sea bream aquaculture.

열교환기 내부 유로의 꺾임각 변화에 따른 국소 열/물질전달 특성 고찰 (Effects of Corrugation Angle on Local Heat/Mass Transfer in Wavy Duct of Heat Exchanger)

  • 장인혁;황상동;조형희
    • 대한기계학회논문집B
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    • 제28권7호
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    • pp.789-799
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    • 2004
  • An experimental study is conducted to investigate the effects of duct corrugation angle on heat/mass transfer characteristics in wavy ducts of a primary surface heat exchanger application. Local heat/mass transfer coefficients on the wavy duct sidewalls are determined by using a naphthalene sublimation technique. The corrugation angles(${\alpha}$) of the wavy ducts are 145$^{\circ}$, 130$^{\circ}$, 115$^{\circ}$ and 100$^{\circ}$. And the Reynolds numbers based on the duct hydraulic diameter vary from 300 to 3,000. The results show that at the low Re(Re $\leq$1000), the secondary vortices called Taylor-Gortler vortices perpendicular to the main flow direction are generated due to effect of duct curvature. By these secondary vortices, high heat/mass transfer regions are formed on both pressure-side and suction-side walls. At the high Re(Re $\geq$ 1000), these secondary flows are vanished with helping flow transition to turbulent flow and the regions which show high heat/mass coefficients by flow reattachment are formed on suction side. As corrugation angle decreases, the local peak Sh induced by Taylor-Gortler vortices increase at Re $\leq$1000. At high Re(Re $\geq$ 1000), by the existence of different kind of secondary flows called Dean vortices, non-uniform Sh distribution appears along spanwise direction at the narrow corrugation angle (${\alpha}$=100$^{\circ}$). Average Sh also increase by the enhanced effect of secondary vortices and flow reattachment. More pumping power (pressure loss) is required with the smaller corrugation angle due to the enhancement of flow instability.

계류 고환염전으로 오인된 드문 형태의 고환 림프종: 증례 보고 (Unusual Presentation of a Testicular Lymphoma Mimicking a Missed Testicular Torsion: A Case Report)

  • 김미진;이영환;김유리
    • 대한영상의학회지
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    • 제82권5호
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    • pp.1287-1291
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    • 2021
  • 고환 림프종은 무통성 종괴를 주소로 내원하는 드문 고환 종양이다. 일반적으로 고환 림프종은 칼라 도플러 초음파에서 고혈관성을 보이며, 컴퓨터단층촬영이나 자기공명영상에서 조영증강을 보인다. 저자들은 우측 고환 종대를 주소로 내원한 67세 환자에서 초음파 검사상 크기가 커진 고환 내 혈류가 보이지 않아 계류염전으로 진단하였으나, 전산화단층촬영에서는 주변부에 일부 조영증강을 보이는 종괴로 관찰되었고, 수술 이후 림프종이 진단된 증례를 경험하여 보고하고자 한다.

Extranodal Malignant Lymphoma Concurrent Involving Female Urethra and Cervix: a Case Report

  • Kim, Dong Chan;Kim, You Me
    • Investigative Magnetic Resonance Imaging
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    • 제24권3호
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    • pp.168-173
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    • 2020
  • Extranodal lymphoma presents in almost one-third of all non-Hodgkin lymphoma cases. The gastrointestinal tract, skin, and central nervous system are common sites of involvement, whereas the urethra and cervix are very rare. To the best of our knowledge, this is the first report on concurrent extranodal involvement of the uterine cervix and urethra. We report imaging findings of malignant lymphoma involving urethra and cervix concurrently in a 79-year-old female patient with literature review. The magnetic resonance imaging showed huge intermediate to high signal intensity mass on T2 weighted images and strong homogeneous enhancement in uterine cervix and periurethral area, but no surrounding architectural disruption.

공냉형 수직 흡수식 시스템의 적용에 관한 연구 (A study on The Application of a Vertical Absorption System Cooled by Air)

  • 김정국;조금남
    • 한국에너지공학회:학술대회논문집
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    • 한국에너지공학회 2003년도 춘계 학술발표회 논문집
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    • pp.351-357
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    • 2003
  • In absorption system, the performance of the absorber is critical the overall system performance, size, and first-cost. The objective of this paper is to provide a comprehensive review of the significant effects that researchers have made to numerically analysis model the coupled heat and mass transfer process that occur during falling-film absorption and experimental researches. This study includes experimental work in the enhancement of absorption performance, the effect of the geometry of a vertical absorber, and the effect of configuration of absorption system. This paper is used to highlight key areas which need attention such as film ans vapor hydrodynamics, especially the non-periodicity, instability, and recirculatory motion of waves in the vertical absorber case.

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부산지역 내륙과 해안의 $PM_{10}$ 중의 금속농도와 이온농도 특성 (Characteristics of Metallic and Ionic Concentration in $PM_{10}$ at Inland and Seashore in Busan)

  • 전병일;황용식;오광중
    • 환경영향평가
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    • 제19권3호
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    • pp.323-333
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    • 2010
  • $PM_{10}$ mass were measured in Gwaebeopdong (inland) and Dongsamdong (seashore) of Busan in summer and fall, 2007 and the 24-hour averaged samples were analyzed to investigate temporal and spatial variability of metallic elements and water-soluble ions in $PM_{10}$. Overall average concentrations of $PM_{10}$ mass during the study period were 72.7 ${\mu}g/M^3$ and 64.3 ${\mu}g/M^3$ in Gwaebeopdong and Dongsamdong, respectively. As for metal elements, averaged concentrations of crustal components, Ca, Fe, K, Mn, and Ti, in Gwaebeopdong exhibited enhancement relative to Dongsamdong. Non-crustal elements, Pb and Cu, displayed elevated levels in Gwaebeopdong while Ni and Zn were observed to be high in Dongsamdong. Averaged nitrate concentration in Gwaebeopdong (6.36 ${\mu}g/M^3$) was greater than in Dongsamdong(5.68 ${\mu}g/M^3$) and both areas had higher level of nitrate in summer than in fall. Averaged sulfate concentrations in Dongsamdong (25.4%) exhibited elevated level relative to Gwaebeopdong (19.4%). Overall average contribution of water-soluble ions to $PM_{10}$ in Dongsamdong (47.5%) was higher than in Gwaebeopdong (37.8%). The average mass fractions of secondary ions in $PM_{10}$ were elevated in Dongsamdong (37.1%) as compared to Gwaebeopdong (31.4%). Equivalent ratio of [${SO_4}^{2-}/NO_3{^-}$] was seen to be lower in Gwaebeopdong (1.39) than that in Dongsamdong (1.79) and consistently higher in summer than in fall for both areas.