• 제목/요약/키워드: $V_S$-profile

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자유수면에서 블레이드 수 변화가 마이크로 중력식 와류 수차 성능에 미치는 영향 (Effect of Blade Number Variations on Performance of Micro Gravitational Vortex Turbine in Free Water Surface)

  • 김종우;최인호;정기수
    • 한국습지학회지
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    • 제25권3호
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    • pp.176-183
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    • 2023
  • 본 연구는 자유수면 아래 원통형 와류발생부에서 와류 수차 성능에 대한 블레이드 수가 미치는 영향을 이해하는 것이다. 동일한 블레이드 형상을 사용하여 상대 와류 수심비(y/hv) 0.065 ~ 0.417 범위에 설치된 2개, 3개, 4개, 5개 및 6개의 블레이드로 마이크로 와류 수차의 성능을 실험하였다. 연구 결과로서 블레이드 수가 증가함에 따라 회전수, 전압, 전류 및 출력이 유속 0.7 m/s 이하일 때 상대 와류 수심비 0.065와 0.111 지점에서 증가한다. 5개 블레이드 수차의 평균 출력은 다른 블레이드 수보다 높게 나타난다. 오리피스 근처에 설치된 직경 130 mm인 4개의 블레이드 수차의 성능이 와류발생부에서 동일한 수의 직경 220 mm인 블레이드 수차보다 높다.

1 ${\mu}m$ CMOS 소자의 대칭적인 문턱전압 결정을 위한 최적 이온주입 시뮬레이션 (Simulation of optimal ion implantation for symmetric threshold voltage determination of 1 ${\mu}m$ CMOS device)

  • 서용진;최현식;이철인;김태형;김창일;장의구
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1991년도 추계학술대회 논문집 학회본부
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    • pp.286-289
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    • 1991
  • We simulated ion implantation and annealing condition of 1 ${\mu}m$ CMOS device using process simulator, SUPREM-II. In this simulation, optimal condition of ion implantation for symmetric threshold voltage determination of PMOS and NMOS region, junction depth and sheet resistance of source/drain region, impurity profile of each region are investigated. Ion implantation dose for 3 ${\mu}m$ N-well junction depth and symmetric threshold voltage of $|0.6|{\pm}0.1$ V were $1.9E12Cm^{-2}$(for phosphorus), $1.7E122Cm^{-2}$(for boron) respectively. Also annealing condition for dopant activation are examined about $900^{\circ}C$, 30 minutes. After final process step, N-well junction, P+ S/D junction and N+ S/D junction depth are calculated 3.16 ${\mu}m$, 0.45 ${\mu}m$ and 0.25 ${\mu}m$ respectively.

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LYα LINE FORMATION IN HUBBLE-TYPE SPHERICAL OUTFLOWS IN STARBURST GALAXIES

  • AHN SANG-HYEON;LEE HEE-WON
    • 천문학회지
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    • 제35권4호
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    • pp.175-185
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    • 2002
  • Almost half of primeval galaxies show P-Cygni type profiles in the Ly$\alpha$ emission line. The main underlying mechanism for the profile formation in these systems is thought to be the frequency re-distribution of the line photons in expanding scattering media surrounding the emission source. A Monte Carlo code is developed to investigate the Ly$\alpha$ line transfer in an optically thick and moving medium with a careful consideration of the scattering in the damping wings. Typical column densities and expansion velocities of neutral hydrogen investigated in this study are $N_{H1}{\~}10^{17-20}\;cm^{-2}$ and ${\Delta}V{\~} 100 km\;s^{-1}$. We investigate the dependence of the emergent profiles on the kinematics and on the column density. Our numerical results are applied to show that the damped Ly$\alpha$ absorbers may possess an expanding H I supershell with bulk flow of ${\~}200 km\;s^{-l}$ and H I column density $N_{H1}{\~}10^{19}\;cm^{-2}$. We briefly discuss the observational implications.

CCSEM을 이용한 대기 중 개별분진의 분류에 관한 연구 (Classification of Individual Ambient Particles by CCSEM)

  • 장여진;김동술
    • 한국대기환경학회지
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    • 제13권5호
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    • pp.345-353
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    • 1997
  • The purpose of the study was to stastically classify individual PM-10 measured by SEM/EDX (scanning electron microscopy/energy dispersive x-ray analyzer). The SEM/EDX provided various physical parameters like optical diameter, as well as major 18 chemical information (Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Pb) for a particle-by-particle basis. The total of 1,419 particles were analyzed for the study. Thus density and mass of each particle can be estimated based on its chemical composition. Further the study developed 4 semisource profiles including highway, oil boiler, incinerator, and soil emissions, where each sample was collected near the source in the ambient air The profiles developed were consisted of mass fractions and their uncertainties based on a particle class concept. To obtain mass fraction of each particle class, an agglomerative hierarchical cluster analysis was initially applied to create particle classes for each sample. Then uncertainties were calculated for each class based on the jacknife method. The 1,258 particles out of 1,419 (88.7%) were assorted in newly generated particle classes. The study provides opportunities to identify particle's source quantitatively and to develope various receptor models.

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Primary Central Nervous System Lymphoma: A Clinicopathological and Cytomorpholgical Study from A Tertiary Care Centre in Chennai, India

  • Ambroise, M. Moses;Ghosh, Mitra;Mallikarjuna, V.S.;Annapurneswari, S.;Kurian, Ann;Chakravarthy, Ranjani
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권2호
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    • pp.727-731
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    • 2013
  • Background: The aim of this study was to analyze the clinicopathological and immunohistochemical features of primary central nervous system lymphoma (PCNSL) cases occurring in Indian patients and also study the utility of the crush smear preparation in intraoperative diagnosis. Materials and Methods: The immune status, clinical, radiological details, immunohistochemical profile, histopathological findings and cytological features in smear preparation of 32 cases of PCNSL were analyzed. Patients with systemic NHL and skull-base lymphomas were excluded. Results: The mean age of our patients was 52 years with a male: female ratio 1:1. A periventricular location was found in 62.5% of patients. None of our PCNSL cases were associated with AIDS. All cases except one were diffuse large B-cell lymphomas. Intraoperative diagnosis using crush smears allowed correct prediction in 93% of cases. Conclusions: Our study shows that PCNSL is seen predominantly in immunocompetent patients in India. The age of presentation is relatively young as compared to the West. Our study also stresses the utility of crush smear preparation in establishing an intraoperative diagnosis.

Development and Applications of TOF-MEIS (Time-of-Flight - Medium Energy Ion Scattering Spectrometry)

  • Yu, K.S.;Kim, Wansup;Park, Kyungsu;Min, Won Ja;Moon, DaeWon
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.107.1-107.1
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    • 2014
  • We have developed and commercialize a time-of-flight - medium energy ion scattering spectrometry (TOF-MEIS) system (model MEIS-K120). MEIS-K120 adapted a large solid acceptance angle detector that results in high collection efficiency, minimized ion beam damage while maintaining a similar energy resolution. In addition, TOF analyzer regards neutrals same to ions which removes the ion neutralization problems in absolute quantitative analysis. A TOF-MEIS system achieves $7{\times}10^{-3}$ energy resolution by utilizing a pulsed ion beam with a pulse width 350 ps and a TOF delay-line-detector with a time resolution of about 85 ps. TOF-MEIS spectra were obtained using 100 keV $He^+$ ions with an ion beam diameter of $10{\mu}m$ with ion dose $1{\times}10^{16}$ in ordinary experimental condition. Among TOF-MEIS applications, we report the quantitative compositional profiling of 3~5 nm CdSe/ZnS QDs, As depth profile and substitutional As ratio of As implanted/annealed Si, Ionic Critical Dimension (CD) for FinFET, Direct Recoil (DR) analysis of hydrogen in diamond like carbon (DLC) and InxGayZnzOn on glass substrate.

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LiMnBO3/C: A Potential Cathode Material for Lithium Batteries

  • Aravindan, V.;Karthikeyan, K.;Amaresh, S.;Lee, Y.S.
    • Bulletin of the Korean Chemical Society
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    • 제31권6호
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    • pp.1506-1508
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    • 2010
  • $LiMnBO_3$ was successfully synthesized by a solid-state reaction method both with and without a carbon coating. Adipic acid was used as source material for the carbon coating. $LiMnBO_3$ was composed of many small polycrystalline particles with a size of about 50 - 70 nm, which showed a very even particle morphology and highly ordered crystalline particulates. Whereas the carbon coated $LiMnBO_3$ was well covered by mat-like, fine material consisting of amorphous carbon derived from the carbonization of adipic acid during the synthetic process. Carbon coated cell exhibited improved and stable discharge capacity profile over the untreated. Two cells delivered an initial discharge capacity of 111 and 58 mAh/g for $LiMnBO_3$/C and $LiMnBO_3$, respectively. Carbon coating on the surface of the $LiMnBO_3$ drastically improved discharge capacity due to the improved electric conductivity in the $LiMnBO_3$ material.

Genome Profiling for Health Promoting and Disease Preventing Traits Unraveled Probiotic Potential of Bacillus clausii B106

  • Kapse, N.G.;Engineer, A.S.;Gowdaman, V.;Wagh, S.;Dhakephalkar, P.K.
    • 한국미생물·생명공학회지
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    • 제46권4호
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    • pp.334-345
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    • 2018
  • Spore-forming Bacillus species are commercially available probiotic formulations for application in humans. They have health benefits and help prevent disease in hosts by combating entero-pathogens and ameliorating antibiotic-associated diarrhea. However, the molecular and cellular mechanisms of these benefits remain unclear. Here, we report the draft genome of a potential probiotic strain of Bacillus clausii B106. We mapped and compared the probiotic profile of B106 with other reference genomes. The draft genome analysis of B106 revealed the presence of ADI pathway genes, indicating its ability to tolerate acidic pH and bile salts. Genes encoding fibronectin binding proteins, enolase, as well as a gene cluster involved in the biosynthesis of exopolysaccharides underscored the potential of B106 to adhere to the intestinal epithelium and colonize the human gut. Genes encoding bacteriocins were also detected, indicating the antimicrobial ability of this isolate. The presence of genes encoding vitamins, including Riboflavin, Folate, and Biotin, also indicated the health-promoting ability of B106. Resistance of B106 to multiple antibiotics was evident from the presence of genes encoding resistance to chloramphenicol, ${\beta}$-lactams, Vancomycin, Tetracycline, fluoroquinolones, and aminoglycosides. The findings indicate the significance of B. clausii B106 administration during antibiotic treatment and its potential value as a probiotic strain to replenish the health-promoting and disease-preventing gut flora following antibiotic treatment.

Aureivirga callyspongiae sp. nov., Isolated from Marine Sponge Callyspongia elegans

  • Park, So Hyun;Kim, Ji Young;Heo, Moon Soo
    • 한국미생물·생명공학회지
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    • 제49권3호
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    • pp.384-390
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    • 2021
  • A Gram-negative, aerobic, motile by gliding, and rod-shaped marine bacterium, designated CE67T was isolated from the marine sponge Callyspongia elegans on Biyang-do in Jeju Island. The CE67T strain grew optimally at 25℃, pH 7.5, and in the presence of 2-3% (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain CE67T was related to the genus Aureivirga and had the highest 16S rRNA gene sequence similarity to the Aureivirga marina VIII.04T type strain (96.3%). The primary fatty acids (>10%) of strain CE67T were iso-C15:0 (35.3%) and iso-C17:0 3OH (21.8%). The polar lipid profile of strain CE67T contained phosphatidylethanolamine, unidentified aminolipids, and unidentified lipids. The predominant menaquinone was MK-6. The DNA G+C content was 29.1 mol%. Based on the polyphasic taxonomic analysis, strain CE67T was determined to be a representative novel species of the genus Aureivirga for which we propose the name Aureivirga callyspongiae sp. nov., whose strain type is CE67T (=KCTC 42847T=JCM 34566T).

Elastic settlements of identical angular footings in close proximity

  • R. Sarvesha;V. Srinivasan;Anjan Patelb
    • Geomechanics and Engineering
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    • 제32권2호
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    • pp.193-207
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    • 2023
  • In general, the numerous classical approaches available in the literature can anticipate the settlement of shallow foundations. As long as the footings are not in close proximity to other subsurface buildings, the findings achieved using these methods are legitimate and acceptable. However, due to increased urbanisation and land scarcity, footings are frequently built close together. As a result, these footings' settlement behaviour differs from those of isolated footings. A simpler approach for assessing the settlement behaviour of two square or rectangular footings placed in close proximity is presented in this work. A Parametric study has been carried out to examine the interference effect on the settlement of these footings placed in close vicinity on the surface of a homogeneous, isotropic and elastic soil medium. The interaction factors are examined by varying the different aspect ratios (L/B), clear spacing ratio (S/B) and intensity of loading on the right footing with respect to the left footing. Further, variation of the settlement ratio (δ/B) with respect to embedment depth ratio Df/B is examined. For square and rectangular footings, the interference settlement profile is also investigated by varying the clear spacing ratio (S/B) and the degree of loading. The results were compared to 3D finite element analysis and experimental data that were available.