• 제목/요약/키워드: 6M model

검색결과 3,895건 처리시간 0.032초

Facilitated Transport of Cr(VI) through a Supported Liquid Membrane with a Carrier

  • Park, Sang-Wook;Lee, Jae-Wook;Kim, Sung-Soo;Choi, Byoung-Sik
    • 한국응용과학기술학회지
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    • 제20권2호
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    • pp.154-164
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    • 2003
  • This paper has applied a simple model to the mass transfer mechanism of Cr(VI) with crownether in a batch-type, supported liquid membrane module. Concentration at pH 3 are as follows : 0.012 kmol/$m^3{\le}$18-crown-6${\le}$0.036 kmol/$m^3$ and 20 g/$m^3{\le}$ Cr(VI)${\le}$500 g/$m^3$. The measured values of forward- and backward-reaction rate constants between Cr(VI) and 18-crown-6 were used to simulate the model with the mass conservation equation and associated boundary conditions. Comparison between the experimental and simulated facilitated factor of Cr(VI) transport led to classification of reaction regions.

HTMAB로 표면처리된 안트라사이트에 의한 비소 및 셀렌 이온의 흡착 특성 (Adsorption Characteristics of As and Se Ions by HTMAB Modified Anthracite)

  • 김정배
    • 한국환경과학회지
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    • 제27권3호
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    • pp.167-177
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    • 2018
  • The removal characteristics of As and Se ions from aqueous solution by hexadecyl trimethyl ammonium bromide (HTMAB) modified anthracite (HTMAB-AT) were investigated under various conditions of contact time, pH and temperature. When the pH is 6, the zeta potential value of anthracite (AT) is -24 mV and on the other hand, the zeta potential value of the HTMAB-AT is +44 mV. It can be seen that the overall increase of about 60 mV. Increasing the (+) potential value indicates that the surface of the adsorbent had a stronger positive charge, so adsorption for the anion metal was increased. The isotherm data was well described by Langmuir and Temkin isotherm model. The maximum adsorption capacity was found to be 7.81 and 6.89 mg/g for As and Se ions from the Langmuir isotherm model at 298 K, respectively. The kinetic data was tested using pseudo first and pseudo second order models. The results indicated that adsorption fitted well with the pseudo second order kinetic model. The mechanism of the adsorption process showed that adsorption was dependent on intra particle diffusion model according to two step diffusion. The thermodynamic parameters(${\Delta}G^{\circ}$, ${\Delta}H^{\circ}$, and ${\Delta}S^{\circ}$) were also determined using the equilibrium constant value obtained at different temperatures. The thermodynamic parameters indicated that the adsorption process was physisorption, and also an endothermic and spontaneous process.

Mechanical and Thermal Behavior of Polyamide-6/Clay Nanocomposite Using Continuum-based Micromechanical Modeling

  • Weon, Jong-Il
    • Macromolecular Research
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    • 제17권10호
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    • pp.797-806
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    • 2009
  • The mechanical and thermal behaviors of polyamide-6/clay nanocomposites were studied using the continuum-based, micromechanical models such as Mori-Tanaka, Halpin-Tsai and shear lag. Mechanic-based model prediction provides a better understanding regarding the dependence of the nanocomposites' reinforcement efficiency on conventional filler structural parameters such as filler aspect ratio ($\alpha$), filler orientation (S), filler weight fraction (${\Psi}_f$), and filler/matrix stiffness ratio ($E_f/E_m$). For an intercalated and exfoliated nanocomposite, an effective, filler-based, micromechanical model that includes effective filler structural parameters, the number of platelets per stack (n) and the silicate inter-layer spacing ($d_{001}$), is proposed to describe the mesoscopic intercalated filler and the nanoscopic exfoliated filler. The proposed model nicely captures the experimental modulus behaviors for both intercalated and exfoliated nanocomposites. In addition, the model prediction of the heat distortion temperature is examined for nanocomposites with different filler aspect ratio. The predicted heat distortion temperature appears to be reasonable compared to the heat distortion temperature obtained by experimental tests. Based on both the experimental results and model prediction, the reinforcement efficiency and heat resistance of the polyamide-6/clay nanocomposites definitely depend on both conventional (${\alpha},\;S,\;{\Psi}_f,\;E_f/E_m$) and effective (n, $d_{001}$) filler structural parameters.

도시농업을 위한 소형온실 설계요인 분석 및 구조모델 개발 (Development of Structural Model and Analysis of Design Factors for Small Greenhouse of Urban Agriculture)

  • 김형권;유영선;김영화;이태석;오성식;이원석;김용현
    • 생물환경조절학회지
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    • 제28권4호
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    • pp.388-395
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    • 2019
  • The purpose of this study is to suggest structural model and analyze design factors for the development of small greenhouse standardization model. The average dimensions of small greenhouse desired by urban farmers were 3.3m in width, 1.9m in eaves height, 2.7m in ridge height, 5.7m in length. The cladding materials for small greenhouse were preferred to glass, PC board and plastic film, framework to aluminum alloy and steel, and heating method in electrical energy. In addition, it was analyzed that small greenhouses need to develop structural model by dividing them into entry-level type and high-level type. The roof type that was used for entry-level type was arch shape, framework was steel pipe, cladding material was plastic film. On the other hand, high-level type was used in even span or dutch light type, framework with square hollow steel, cladding materials with glass or PC board. In consideration of these findings and practicality, this study developed four types of small greenhouses. The width, eaves height, ridges height, and length of the small greenhouses of even span type, which were covered with 5mm thick glass and 6mm thick PC board were 3m, 2.2m, 2.9m, and 6m, respectively. The small greenhouse of dutch light type covered with 5mm thick glass was designed with 3.8m in with, 2.2m in eaves height, 2.9m in ridges height, and 6m in length. The width, eaves height, ridges height, and length of the arch shape small greenhouse covered with a 0.15mm PO film were 3m, 1.5m, 2.8m, and 6m, respectively.

벼에 의한 인산흡수의 기작에 관한 연구 (A Kinetic Study of Phosphate Absorption by Rice Roots)

  • 장남기
    • Journal of Plant Biology
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    • 제21권1_4호
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    • pp.33-38
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    • 1978
  • Phosphate absorption from a Na2H32PO4 solution by Oryza sativa L. was studied in order to elucidate kinetic mechanisms of ion transport. The rates of phosphate absorption from different concentraitons indicated the presence of dual mechanisms in root tips, one in the low (1$\times$10-6 to 8$\times$10-5M) and the other in the high (1$\times$10-4 to 8$\times$10-3M). A phosphate compensation point of phosphate transport was revealed with a 1$\times$10-6M solution of Na2H32PO4. The kinetic model that ion transport involves an exchange reaction of absorption and desorptin is prosposed as follows: where C represents an ionic-specific organic carrier in the membrane; M, Mo and Mi are the mineral ions, M-outside and M-inside; MC is a carrier-ion complex; and the K's represent rate constants. In this model, the Mi velocity, v, is given by: {{{{v= {dMi} over {dt}= {(K1K3Mo-K2K4Mi) Ct} over {(K2+K3)+K1Mo+K4Mi} }} where Ct is equal to C+MC, and t is time.

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목조주택 모형개발을 위한 평면모듈 설정에 대한 연구 - 기둥-보 방식 구조를 중심으로 - (A study on the Plan Modular Establishment for the Development of Wooden Dwelling Model - Focused on the Post & Beam Structure -)

  • 강만호;주석중;김재덕
    • 한국주거학회논문집
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    • 제18권1호
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    • pp.141-148
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    • 2007
  • In this research, to develope wooden house model with post & beam structure which is commensurate with domestic environment, we analyzed the size and module of a unit space and space organization of existing habitation, then, based on the result, we tried to suggest general wood house modules. For this, we investigated 98 floor plans for 30 pyeong apartment in Seoul, Gyounggi-do, Gwangju, and Jeolla-do. The results are showed as follows. 1) It has shown that 7 posts distances are available in 2 bay floor plan type - 3.0 m, 3.3 m, 3.6 m, 3.9 m, 4.2 m, 4.5 m, and 4.8 m. 2) It has shown that 8 posts distances are available in 3 bay floor plan type - 3.0 m, 3.3 m, 3.6 m, 3.9 m, 4.2 m, 4.5 m, 4.8 m, and 5.1 m. It was concluded as follows, applying the standard of regulations of horizontal modular coordination design, from $\ulcorner$the standard of modular coordination design in architecture(KSF 1525)$\lrcorner$. 1) The available widths are 3.0 m, 3.3 m, 3.6 m, 4.2 m, and 4.8 m, and the available depths are 3.0 m, 3.3 m, 3.6 m, and 4.2 m. 2) To guarantee a space through post module of a room combination, we can use a module of 3.6 m, 4.2 m, 4.8 m except 3.0 m, 3.3 m among available modules. The module investigated in post & beam structure wooden house is applied in basic 6 floor plans as follows. 1) When organize the room on the basis of tile module of 3.6 m, 4.2 m, it was possible to organize the floor plan. 2) After arranging main room, making practical application of variableness which is advantage of post & beam structure, putting to practical use of extra space that becomes the combination of atypical room such as kitchen, dining room, and bathroom, it was possible to organize the floor plan of the residence. 3) It is possible to organize whole rooms through the plan module from 3.6 m to 4.2 m, that decides the floor plan of a wooden house.

근접굴착 시 벽체에 선행하중 재하에 따른 터널의 거동 (Behavior of tunnel under the influence of pre-loading on braced wall during the adjacent ground excavation)

  • 김일;이상덕
    • 한국터널지하공간학회 논문집
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    • 제9권4호
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    • pp.331-341
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    • 2007
  • 기존터널에 근접 굴착 할 때 발생하는 흙막이벽체의 수평변위를 억제시키기 위해 버팀대에 선행하중을 가했다. 이러한 목적으로 흙막이벽체에 큰 선행하중을 가할 수 있는 새로운 선행하중 시스템을 모형시험에 적용하였다. 대형 시험은 폭 2.0m, 높이 6.0m, 길이 4.0m인 모형 토조에서 수행하였고 시험지반은 모래로 조성하였다. 직경 1.2m인 모형 터널은 시험지반 굴착 전에 설치하고 지반을 조성한 후에 모형터널에 근접해서 흙막이벽체를 설치하고 시험지반을 굴착하면서 모형 터널과 흙막이벽체 및 지반의 거동을 측정하였다. 이때에 선행하중 재하효과를 확인하기 위하여 선행하중을 가하지 않는 시험은 물론 선행하중을 가하여 흙막이벽체의 수평변위를 억제하는 시험을 실시하였고 수치해석을 실시하여 대형 시험결과와 비교하였다. 그 결과 선행하중을 설계축력 이상으로 적용시켜 흙막이벽체의 수평변위를 감소시켰을 때 벽체 배면에 있는 기존 터널의 안정성이 크게 향상되는 것을 확인할 수 있었다.

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모형실험에 의한 트러스형 리프트 게이트의 진동 특성 (Dynamic Characteristic of Truss Type Lift Gate by Model Tests)

  • 이성행;신동욱;김경남;정경섭
    • 대한토목학회논문집
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    • 제32권6A호
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    • pp.337-345
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    • 2012
  • 본 연구에서는 4대강 사업으로 건설중인 트러스형 리프트의 진동특성을 검토하기 위하여 모형실험이 수행된다. 경간 40 m, 높이 9 m의 트러스형 리프트게이트를 축척 1/25로 모형이론에 따라 아크릴과 납으로 모형을 제작하고, 폭 1.6 m, 길이 25 m, 높이 0.8 m의 수로에서 실험된다. 먼저 모형의 고유진동수가 측정되고 모형을 검증하기 위하여 유한요소 해석결과와 비교된다. 검증된 모형에서 상하류 수위와 문비 개방고에 따른 진동가속도 진폭이 측정된다. 또한 문비의 진동을 줄 일수 있는 하부형상을 검토하기 위하여 문비 최하부의 각도가 $20^{\circ}$, $35^{\circ}$, $50^{\circ}$인 모형을 제작하고 실험결과를 서로 비교한다. 실험 결과는 수문 조작 시 유지관리지침의 기본 자료를 제공하고, 수문의 진동특성과 진동을 줄일 수 있는 수문의 하부형상을 검토한다.

Novel Resectable Myocardial Model Using Hybrid Three-Dimensional Printing and Silicone Molding for Mock Myectomy for Apical Hypertrophic Cardiomyopathy

  • Wooil Kim;Minje Lim;You Joung Jang;Hyun Jung Koo;Joon-Won Kang;Sung-Ho Jung;Dong Hyun Yang
    • Korean Journal of Radiology
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    • 제22권7호
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    • pp.1054-1065
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    • 2021
  • Objective: We implemented a novel resectable myocardial model for mock myectomy using a hybrid method of three-dimensional (3D) printing and silicone molding for patients with apical hypertrophic cardiomyopathy (ApHCM). Materials and Methods: From January 2019 through May 2020, 3D models from three patients with ApHCM were generated using the end-diastolic cardiac CT phase image. After computer-aided designing of measures to prevent structural deformation during silicone injection into molding, 3D printing was performed to reproduce anatomic details and molds for the left ventricular (LV) myocardial mass. We compared the myocardial thickness of each cardiac segment and the LV myocardial mass and cavity volumes between the myocardial model images and cardiac CT images. The surgeon performed mock surgery, and we compared the volume and weight of the resected silicone and myocardium. Results: During the mock surgery, the surgeon could determine an ideal site for the incision and the optimal extent of myocardial resection. The mean differences in the measured myocardial thickness of the model (0.3, 1.0, 6.9, and 7.3 mm in the basal, midventricular, apical segments, and apex, respectively) and volume of the LV myocardial mass and chamber (36.9 mL and 14.8 mL, 2.9 mL and -9.4 mL, and 6.0 mL and -3.0 mL in basal, mid-ventricular and apical segments, respectively) were consistent with cardiac CT. The volume and weight of the resected silicone were similar to those of the resected myocardium (6 mL [6.2 g] of silicone and 5 mL [5.3 g] of the myocardium in patient 2; 12 mL [12.5 g] of silicone and 11.2 mL [11.8 g] of the myocardium in patient 3). Conclusion: Our 3D model created using hybrid 3D printing and silicone molding may be useful for determining the extent of surgery and planning surgery guided by a rehearsal platform for ApHCM.