• 제목/요약/키워드: Surface area

검색결과 11,232건 처리시간 0.043초

철전기분해장치(FNR)에서 철판의 표면적이 인제거에 미친 영향에 관한 연구 (A Study on Phosphorus Removal Effects Per Iron Surface Area in FNR Process)

  • 김영규
    • 한국환경보건학회지
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    • 제38권6호
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    • pp.568-574
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    • 2012
  • Objectives: The purpose of this experiment is to understand the phosphorus removal ratio effects of iron plates per unit of surface area through the iron electrolysis system, which consists of an anoxic basin, aerobic basin, and iron precipitation apparatus. Methods: Iron electrolysis, which uses an iron precipitation reactor in anoxic and oxic basins, consisted of iron plates with total areas of 400 $cm^2$, 300 $cm^2$ and 200 $cm^2$ respectively. The FNR process was operated with a hydraulic retention time and a sludge retention time of 12 hours and three days, respectively. Wastewater used in the experiments was prepared by dissolving $KH_2PO_4$ in influent water. Results: The iron plates 400 $cm^2$ (16.6 $mA/cm^2$), 300 $cm^2$ (13.3 $mA/cm^2$) and 200 $cm^2$ (7.3 $mA/cm^2$) in surface area in the phosphorus reactor had respective phosphorus of 2.4 mg/l, 2.7 mg/l and 3.2 mg/l in the effluent and phosphorus removal respective efficiencies of 90.3%, 89.1% and 87.1%. The effluent in the reactor, where the iron plate was not used, had relatively very low phosphorus removal efficiency showing phosphorus concentration of 15.3 mg/l and a phosphorus removal efficiency about 38.3%. Phosphorus removal per ferrous was 0.472 mgP/mgFe in the iron electrolysis system where the surface area of iron was low. Phosphorus pollution load per active surface area and the phosphorus removal efficiency had an interrelation of RE = -0.27LS + 89.0 (r = 0.85). Conclusion: With larger iron plate surface area, the elution of iron concentration and phosphorus removal efficiency was higher. The removal efficiency of phosphorus has decreased by increasing the initial phosphate concentration in the iron electrodes. This shows a tendency of decreasing phosphorus removal efficiency because of decreasing of iron deposition as the phosphorus pollution load per active surface area increases.

혀의 재건을 위한 부피 및 표면적의 측정 (Estimation of Volume and Surface Area for Reconstruction of Tongue)

  • 박하나로;김희진;정우진;안순현
    • 대한두경부종양학회지
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    • 제27권1호
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    • pp.27-31
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    • 2011
  • Purpose : Anterolateral thigh and radial forearm flap is the most important fasciocutaneous flap widely used for reconstruction of tongue. One important purpose of flap is replacing the volume of tongue but still there is no data about the surface area and volume to be reconstructed after glossectomy. In this paper, surface area and volume is estimated from the 3-dimensionally reconstructed MRI images to see which flap is more ideal and to give the reference value for reconstruction. Materials and Methods : With coronal MRI image, tongue including only the intrinsic muscle is delineated in every section and reconstructed 3-dimensionally and calculated the volume and surface area to be reconstructed according to the degree of glossectomy. This volume and surface area was compared with the volume of anterolateral thigh and radial forearm flap. Results : The volume and surface area to be reconstructed in hemiglossectomy was $39.0{\pm}4.0cm^3$ and $31.8{\pm}2.7cm^2$ respectively. The average thickness of anterolateral thigh flap is $9.4{\pm}2.8mm$ and that of radial forearm is $3.8{\pm}1.0mm$. Comparing the curve of tongue surface area and volume with the volume of flap, the anterolateral thigh flap has more ideal volume to replace the defect. Conclusions : The surface area and volume requested for reconstruction could be suggested and the anterolateral thigh flap has more ideal volume for reconstruction of glossectomy defect.

캐릭터 인형용 밀착커버 패턴개발 프로세스의 가이드라인 (Guidelines of 2D Pattern Development Process for 3D Fitted Cover of Character Toys)

  • 이희란
    • 한국의류산업학회지
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    • 제19권5호
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    • pp.635-645
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    • 2017
  • The industry of character toys is increasing and new characters are constantly being developed. However, the development of 2D cover patterns for toys is time-consuming due to frequent pattern modifications made through trial and error. Studies are now underway to obtain 2D clothing patterns from 3D body data, however, little research has been done on 2D pattern of character toys. This study suggests efficient guidelines to develop 2D cover patterns with a reasonable accuracy and processing time. Two 3D models of a dog and rabbit were used to develop 2D cover patterns. Independent variables of this study are set as 3 levels of triangle area (small, medium, and large) that influence the efficacy of 3D and 2D pattern development. The determination of the appropriate triangular area was based on the area and shape change of the 2D pattern. A medium or large triangle area was shown to be suitable for a character dog with a smooth curved surface. However, the appropriate triangle area was small if the characteristics of the curved surface are complicated as in the case of rabbit. The head of a dog (a double-curved surface) and the curved forepaw of a rabbit (a triangular area) should be small when the characteristics of the curved surface (such as the hind leg of a rabbit having a large convex surface and a small surface area) are complicated. Grouping by 3D surface characteristics could be a suitable guideline for the triangle area selection.

식물의 온도 완화효과에 관한 기초적 연구 (A Quantitative Study on the Effect of Temperature Control by a Shade Tree and the Lawn Area)

  • 안계복;김기선
    • 한국조경학회지
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    • 제14권1호
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    • pp.1-13
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    • 1986
  • The purpose of this study is to investigate the effect of temperature control by a shade tree and the lawn area. In this investigation, we find out that artificial-lawn, concerte, and exposed soil are more higher temperature than covered with plant materials. The results of the measurement may to summerized as follows; 1) Low-temperature effects of zoysia japonica is more controlled by condition of growth than leaf length of grass. Surface temperature make 0.7$^{\circ}C$ difference between long grass (15cm), and short grass (5cm), but make 5$^{\circ}C$ difference between good growth grass (230/10$\textrm{cm}^2$) and bad growth grass (80/10$\textrm{cm}^2$). 2) The surface temperature of the lawn area is 40.5$^{\circ}C$ lower on a maxinum than that of the artificial lawn (July 28, 1985). During the day of summer, shade area under the shade tree is 0.9$^{\circ}C$ lower then lawn area surface temperature, 6.9$^{\circ}C$ lower than bad growth lawn, 10.3$^{\circ}C$ lower than exposed soil, and 18$^{\circ}C$ lower than concrete surface temperature. 3) Natural irrigation effect on the surface temperature fluctuation. But this effect is changed by compositions of ground materials and time-lapse. 4) Sunny day is more effective than cloud day. 5) In summer season, surface temperature make a difference compare to temperature of 0.5-1.5m height from ground : Surface temperature is 3.4$^{\circ}C$ lower at the lawn area (11 a.m.), 4.2$^{\circ}C$ lower at the shade area the shade tree, 12.7$^{\circ}C$ higher at the concrete area (3p.m.), 38.8$^{\circ}C$ higher at the artificial lawn (2p.m.) 6) According to compositions of ground materials and season have specific vertical temperature distribution curve. 7) In summer season, temperature distribution of 0.5-1.5m hight at the shade tree is 4.8-5.7$^{\circ}C$ lower than concrete area (noon-3p.m.)

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일정표면적 변단면 보의 자유진동 (Free Vibrations of Tapered Beams with Constant Surface Area)

  • 이병구;오상진;박창은;이태은
    • 한국소음진동공학회논문집
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    • 제21권1호
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    • pp.66-73
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    • 2011
  • This paper deals with free vibrations of the tapered beams with the constant surface area. The surface area of the objective beams are always held constant regardless shape functions of the cross-sectional depth. The shape functions are chosen as the linear and parabolic ones. Ordinary differential equations governing free vibrations of such beams are derived and solved numerically for determining the natural frequencies. In the numerical examples, hinged-hinged, hinged-clamped and clamped-clamped end constraints are considered. As the numerical results, the relationships between non-dimensional frequency parameters and various beam parameters such as section ratio, surface area ratio, end constraint and taper type are reported in tables and figures. Especially, section ratios of the strongest beam are calculated, under which the maximum frequencies are achieved.

지표포화지역-중간류유출-흙수분저류량 관계: I. 정상류 분석 (Surface Saturation Area-Subsurface Outflow-Soil Moisture Storage Relationships: I. Steady-State Analysis)

  • 이도훈;이은태
    • 물과 미래
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    • 제28권5호
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    • pp.129-140
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    • 1995
  • 다공성 매질에서의 불포화-포화 흐름을 묘사하는 Richards 방정식을 이용한 수치실험을 통하여 경사면에서 지표포화지역-중간류유출 정상류 관계 및 지표포화지역-흙수분저류량 정상류 관계를 유도하였다. 수치실험에서는 지형인자 및 토양 수리특성의 변화가 지표포화지역-중간류유출 관계에 미치는 민감도를 분석하고, 지표포화지역을 중간류유출 또는 흙수분저류량의 함수로 표시하는 멱법칙을 결정하였다.

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Influence of Growth Rate on Biosorption of Heavy Metals by Nocardia amarae

  • Kim, Dong Wook;Daniel K. Cha;Hyung-Joon Seo;Jong Bok Bak
    • Journal of Microbiology and Biotechnology
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    • 제12권6호
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    • pp.878-881
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    • 2002
  • The goal of the current research was to assess the influence of the growth rate of Nocardia amarae on its overall metal binding capacity. Batch sorption isotherms for cadmium (Cd), copper (Cu), and nickel (Ni) showed that Nocardia cells harvested from chemostat cultures at a dilution rate of $0.33d^-1$ had a significantly higher metal sorption capacity than cells grown at 0.5 and $1d^-1$. The cell surface area estimated using a dye technique indicated that pure N. amarae cells grown at a lower growth rate had a significantly more specific surface area than cells harvested from a higher growth rate operation. Accordingly, this difference in the specific surface area seemed to indicate that the higher metal sorption capacity of the slowly growing Nocardia cells was due to their higher specific surface area.

활성탄의 표면 구조 변화에 따른 흡착 특성 연구 (Adsorption properties of surface - modified activated carbon)

  • 김정렬;서문원;신창호;김영호;이근회;지상운
    • 한국연초학회지
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    • 제16권2호
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    • pp.191-197
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    • 1994
  • Relationships between surface structure and adsorption properties of smoke components were investigated in surface-modified and un-modified activated carbon filter cigarettes. Commercially available activated carbon was treated with nitric acid and hydrogen peroxide as oxidant, and their pore volume, surface structure, BET surface area, pore type and size were studied. BET surface area and pore volume were decreased by nitric acid treatment, but median pore diameter was 8.1 $\AA$, which showed better development of pore compared with that of un-modified activated carbon, 6.9 $\AA$. In case of hydrogen peroxide treatment, BET surface area and pore volume were increased. Their pore was found to be a slit type based on V-t plot analysis. Neutralization capacities for bases of different strength (NaHCO3, Na2CO3, NaOEt and NaOH) showed that the majority of the acidic surface groups are of weak acidity. Modification of the activated carbon surface led to a slight change in adsorption properties when analyzing the smoke of triple-filter cigarette with surface-modified activated carbon.

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신발 굽 높이에 따른 Kager씨 삼각의 면적과 후종족부의 표면온도 측정 (Measurement of Kager's Triangle Area and Retrocalcaneal Surface Temperature by shoes heel height)

  • 전병규;여진동;신정섭
    • 한국방사선학회논문지
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    • 제6권6호
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    • pp.521-529
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    • 2012
  • 본 연구의 목표는 신발 굽 높이에 따른 Kager씨 삼각 면적의 방사선영상 변화와 후종족부의 표면온도 변화를 알아보고자 연구하였다. 카이거씨 면적은 단순 방사선촬영검사와 인피니티 영상저장전송시스템을 이용하여 측정 하였다. 후종족부의 표면온도는 전산화적외선체열검사를 이용하여 측정하였다. 운동화 착용 대상자에게 신발 굽 높이가 다른 하이힐을 착용시켜 카이거씨 삼각 면적과 후종족부의 표면온도 차이를 분석 하였다. 하이힐 대상자들은 운동화 대상자들에 비하여 카이거씨 삼각 면적이 $0.88cm^2$, 후종족부의 표면온도가 $1.4^{\circ}C$ 각각 감소하였다. 최고신장과 최저신장의 카이거씨 면적과 표면온도의 차이는 운동화와 하이힐에서 각각 $0.9cm^2$, $1.2cm^2$, $1.6^{\circ}C$, $0.5^{\circ}C$이며 모두 미세한 차이를 나타냈다. 최고체중과 최저체중의 카이거씨 면적과 표면온도의 차이는 운동화와 하이힐에서 각각 $1.8cm^2$, $0.8cm^2$, $1.1^{\circ}C$, $0.2^{\circ}C$이며 체중이 높을수록 카이거씨 면적과 표면온도가 감소하였다. 하이힐 최장시간 착용자와 최저시간 착용자의 카이거씨 면적과 표면온도의 차이는 각각 $0.8cm^2$, $1.4^{\circ}C$, 이며 착용시간이 증가함에 따라 카이거씨 면적과 표면온도가 감소하였다. 결론적으로 하이힐을 장시간 착용하면 후종족부 통증과 혈류 장애를 유발 할 것으로 고려된다.

표면적이 증가된 반코마이신 결정화 공정에서 이온성 액체의 영향 (Effect of Ionic Liquid on Increased Surface Area Crystallization Process for Vancomycin)

  • 김성재;김진현
    • 한국미생물·생명공학회지
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    • 제42권3호
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    • pp.297-301
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    • 2014
  • 본 연구에서는 실리카겔을 이용한 반응액 부피당 표면적(surface area per volume of reaction solution)이 증가된 반코마이신 결정화 공정에서 이온성 액체의 영향을 조사하였다. 실리카겔로 표면적을 증가시킨 경우에 이온성 액체([BMIm][$BF_4$])를 접목하면 결정화 효율을 더욱 향상시킬 수 있었다. 실리카겔을 이용한 표면적이 증가된 결정화에서 이온성 액체(20%, v/v)를 첨가한 경우 결정화 4시간에 반코마이신 결정이 생성되었으며 실리카겔과 이온성 액체를 사용하지 않은 경우보다 결정화에 소요되는 시간을 6배 정도 단축시킬 수 있었다. 또한 이온성 액체 첨가량이 증가함에 따라 반코마이신 결정 입자크기가 감소할 뿐만 아니라 결정이 균일하고 일정해짐을 알 수 있었다.