• Title/Summary/Keyword: Effective size

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Phase Behavior of Simvastatin Drug in Mixtures of Dichloromethane and Supercritical Carbon Dioxide and Microparticle Formation of Simvastatin Drug Usins Supercritical Anti-Solvent Process (디클로로메탄과 초임계 이산화탄소의 혼합용매에서 Simvastatin 약물의 상거동과 초임계 역용매 공정을 이용한 Simvastatin 약물 미세입자의 제조)

  • Oh, Dong-Joon;Lee, Byung-Chul
    • Clean Technology
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    • v.13 no.1 s.36
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    • pp.34-45
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    • 2007
  • Phase behavior of the ternary systems of water-insoluble simvastatin drug, which is well known to be effective drugs for hypercholesterolemia therapy, in solvent mixtures of dichloromethane and supercritical carbon dioxide was investigated to present a guideline of establishing operating conditions in the particle formation of the drugs by a supercritical anti-solvent recrystallization process utilizing dichloromethane as a solvent and carbon dioxide as an anti-solvent. The solubilities of simvastatin in the mixtures of dichloromethane and carbon dioxide were determined as functions of temperature, pressure and solvent composition by measuring the cloud points of the ternary mixtures at various conditions using a high-pressure phase equilibrium apparatus equipped with a variable-volume view cell. The solubility of the drug increased as the dichloromethane composition in solution and the system pressure increases at a fixed temperature. A lower solubility of the drug was obtained at a higher temperature. The second half of this work is focused on the particle formation of the simvastatin drug by a supercritical anti-solvent recrystallization process in a cylindrical high-pressure vessel equipped with an impeller. Microparticles of the simvastatin drug were prepared as functions of pressure (8 MPa to 12 MPa), temperature (303.15 K, 313,15 K), feed flow rate of carbon dioxide, and stirring speed (up to 3000 rpm), in order to observe the effect of those process parameters on the size and shape of the drug microparticles recrystallized.

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Full-scale EFC Study on Oil Recovery and Reuse from Discharge Gas of Tenter Facility in Textile Industry (Full-scale EFC (Electric Fume Collector)를 활용한 텐타공정 배출가스 정화 및 오일 회수)

  • Hwang, Yeal-Soon;Park, Hee-Jae;Chung, Gu-Hoi;Kim, Duk-Hyun;Na, Byung-Ki
    • Clean Technology
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    • v.17 no.3
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    • pp.259-265
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    • 2011
  • The textile industry is suffered from air pollution problems which must be resolved. In particular, white smoke and odor after the tenter process require abatement. The major air pollution problem in the textile industry occurs during the finishing stages, where various chemicals are used for coating the fabrics. Lubricating oils, plasticizers, and water repellent chemicals are the fabric treatment chemicals. The coated fabrics are cured by heating in tenter facility. In this process, most of air pollutants emitted into the air. White smoke is basically made up of tiny solid or liquid particles of VOCs less than one micron in size. The oil mist can be carried over long distance from their point of origin. The most effective method of removing odor from tenter process is to get rid of tiny oil mist at the emitted gas. For this reason, the full-scale EFC (Electric Fume Collector) of 700 CMM was tested for removing odorous substances emitted from tenter facility. As a result of this study, odor and white smoke can be eliminated effectively and quite large amounts of oil can be recovered.

Capability of CO2 on Metal-Organic Frameworks-Based Porous Adsorbents and Their Challenges to Pressure Swing Adsorption Applications (금속-유기 골격계 다공성 흡착제의 이산화탄소 흡착성능과 압력순환흡착 공정 적용의 문제점)

  • Kim, Moon Hyeon;Choi, Sang Ok;Choo, Soo Tae
    • Clean Technology
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    • v.19 no.4
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    • pp.370-378
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    • 2013
  • This review has shown the capability of MOFs and ZIFs materials to adsorb $CO_2$ under typical PSA temperatures and pressures. The usual operating conditions are adsorption temperatures of $15{\sim}40^{\circ}C$ and adsorption pressures of 4~6 bar based on numerous PSA processes which are widely employed in gases industry for adsorptive separation of $CO_2$. The extent of $CO_2$ adsorption on the microporous materials depends on the metal species and organic linkers existing in the frameworks. The pore size and the surface area, and the process variables are the key parameters to be associated with the efficiency of the adsorbents, particularly adsorption pressures if other variables are comparable each other. The MOFs and ZIFs materials require high pressures greater than 15 bar to yield significant $CO_2$ uptakes. They possess a $CO_2$ adsorption capacity which is very similar to or less than that of conventional benchmark adsorbents such as zeolites and activated carbons. Consequently, those materials have been much less cost-effective for adsorptive $CO_2$ separation to date because of very high production price and the absence of commercially-proven PSA processes using such new adsorbents.

Design of In-Wheel Motor for Automobiles Using Parameter Map (파라미터 맵을 이용한 차량용 인휠 전동기의 설계)

  • Kim, Hae-Joong;Lee, Choong-Sung;Hong, Jung-Pyo
    • Journal of the Korean Magnetics Society
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    • v.25 no.3
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    • pp.92-100
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    • 2015
  • Electric Vehicle (EV) can be categorized by the driving method into in-wheel and in-line types. In-wheel type EV does not have transmission shaft, differential gear and other parts that are used in conventional cars, which simplifies and lightens the structure resulting in higher efficiency. In this paper, design method for in-wheel motor for automobiles using Parameter Map is proposed, and motor with continuous power of 5 kW is designed, built and its performance is verified. To decide the capacity of the in-wheel motor that meets the automobile's requirement, Vehicle Dynamic Simulation considering the total mass of vehicle, gear efficiency, effective radius of tire, slope ratio and others is performed. Through this step, the motor's capacity is decided and initial design to determine the motor shape and size is performed. Next, the motor parameters that meet the requirement is determined using parametric design that uses parametric map. After the motor parameters are decided using parametric map, optimal design to improve THD of back EMF, cogging torque, torque ripple and other factors is performed. The final design was built, and performance analysis and verification of the proposed method is conducted by performing load test.

Is higher dose always the right answer in stereotactic body radiation therapy for small hepatocellular carcinoma?

  • Lee, Kyung Hwa;Yu, Jeong Il;Park, Hee Chul;Park, Su Yeon;Shin, Jung Suk;Shin, Eun Hyuk;Cho, Sungkoo;Jung, Sang Hoon;Han, Young Yih;Lim, Do Hoon
    • Radiation Oncology Journal
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    • v.36 no.2
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    • pp.129-138
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    • 2018
  • Purpose: This study was conducted to compare clinical outcomes and treatment-related toxicities after stereotactic body radiation therapy (SBRT) with two different dose regimens for small hepatocellular carcinomas (HCC) ${\leq}3cm$ in size. Materials and Methods: We retrospectively reviewed 44 patients with liver-confined HCC treated between 2009 and 2014 with SBRT. Total doses of 45 Gy (n = 10) or 60 Gy (n = 34) in 3 fractions were prescribed to the 95% isodose line covering 95% of the planning target volume. Rates of local control (LC), intrahepatic failure-free survival (IHFFS), distant metastasis-free survival (DMFS), and overall survival (OS) were calculated using the Kaplan-Meier method. Results: Median follow-up was 29 months (range, 8 to 64 months). Rates at 1 and 3 years were 97.7% and 95.0% for LC, 97.7% and 80.7% for OS, 76% and 40.5% for IHFFS, and 87.3% and 79.5% for DMFS. Five patients (11.4%) experienced degradation of albumin-bilirubin grade, 2 (4.5%) degradation of Child-Pugh score, and 4 (9.1%) grade 3 or greater laboratory abnormalities within 3 months after SBRT. No significant difference was seen in any oncological outcomes or treatment-related toxicities between the two dose regimens. Conclusions: SBRT was highly effective for local control without severe toxicities in patients with HCC smaller than 3 cm. The regimen of a total dose of 45 Gy in 3 fractions was comparable to 60 Gy in efficacy and safety of SBRT for small HCC.

Anti-pruritic Effect of Botulinum Toxin Type A against Histamine-induced Pruritus on Canine Skin (개에서 Histamine으로 유발한 피부소양증에 대한 보툴리늄 톡신의 항소양 효과)

  • Jeong, Byung-Han;Kim, Tae-Wan;Lee, Keun-Woo;Oh, Tae-Ho
    • Journal of Veterinary Clinics
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    • v.28 no.3
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    • pp.273-279
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    • 2011
  • Botulinum toxin type A (BoNT/A) has been proven to be a safe and effective treatment for wrinkles in human. As well as the anti-wrinkle effects, the anti-pruritic effect of BoNT/A has been revealed from several researches for new therapy. The aim of this study was to investigate the anti-pruritic effect of BoNT/A against histamine-induced pruritus on canine skin. Five clinically healthy beagles were included in the study. All dogs were received 0.05 ml (5 Unit) of BoNT/A on the right dorsal thoracic region as an experiment and the same volume of saline solution was injected on the left dorsal thoracic region as a control, respectively. Intradermal histamine injections were performed four times (before treatment and days 1, 3 and 7 after BoNT/A injection). The severity of pruritus, the diameter and thickness of wheal, the erythema index and cutaneous temperature were assessed. The severity of pruritus was reduced on BoNT/A treated sides, compared with saline treated sides (p < 0.05). BoNT/A decreased wheal size, in both diameter and thickness (p < 0.05). Although, erythema index of both sides were increased after first histamine injection, BoNT/A treated sides showed the low-value as compared with saline treated sides. Cutaneous temperature was decreased significantly on BoNT/A treated sides. These results indicates that BoNT/A reduce histamine-induced pruritus on canine skin and suggested a possibility of application of BoNT/A for local intractable dermatologic problem in dogs.

Plant Growth Responses and Indoor Air Quality Purification in a Wall-typed Botanical Biofiltration System (벽면형 식물바이오필터 내 식물 생육 및 실내공기질 정화)

  • Jung, Seul Ki;Chun, Man Young;Lee, Chang Hee
    • Korean Journal of Plant Resources
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    • v.28 no.5
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    • pp.665-674
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    • 2015
  • The final goal of this research is to develop a botanical biofiltration system, which combines green interior, biofiltering, and automatic irrigation, which can purify indoor air pollutants according to indoor space and the size of biofilter. The biofilter used in this experiment was designed as an integral form of water metering pump, water tank, blower, humidifier, and multi-level planting space in order to be more suitable for indoor space utilization. This study was performed to compare indoor air quality between the space adjacent to a botanical biofilter and the space away from the biofilter (control) without generation of artificial indoor air pollutants, and to evaluate plant growth depending on multiple floors within the biofilter. Each concentration of indoor air pollutants such as TVOCs, monoxide, and dioxide in the space treated with the biofilter was lower than that of control. Dracaena sanderiana ‘Vitoria’ and Epipremnum aureum ‘N Joy’ also showed normal growth responses regardless of multiple floors within the biofilter. Hence, it was confirmed that the wall-typed botanical biofilter suitable for indoor plants was effective for indoor air purification.

Condensable Gas Separation using Phenol! Alumina Composite Activated Carbon Hollow Fiber Membranes (페놀수지/알루미나 복합 활성탄소중공사막을 이용한 응축성 기체 분리)

  • Shin, Kyung-Yong;Park, You-In;Kim, Beom-Sik;Koo, Kee-Kahb
    • Membrane Journal
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    • v.20 no.4
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    • pp.312-319
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    • 2010
  • Carbon membrane materials have received considerable attention for the gas separation including hydrocarbon mixture of ingredients of the volatile organic compounds(VOCs) because they possess their higher selectivity, permeability, and thermal stability than the polymeric membranes. The use of activated carbon membranes makes it possible to separate continuously the VOCs mixture by the selective adsorption-diffusion mechanism which the condensable components are preferentially adsorbed in to the micropores of the membrane. The activated carbon hollow fiber membranes with uniform adsorptive micropores on the wall of open pores and the surface of the membranes have been fabricated by the carbonization of a thin film of phenolic resin deposited on porous alumina hollow fiber membrane. Oxidation, carbonization, and activation processing variables were controlled under different conditions in order to improve the separation characteristics of the activated carbon membrane. Properties of activated carbon hollow fiber membranes and the characterization of a gas permeation by pyrolysis conditions were studied. As the result, the activated carbon hollow fiber membranes with good separation capabilities by the molecular size mechanism as well as selective adsorption on the pores surface followed by surface diffusion effective in the recovery hydrocarbons have been obtained. Therefore, these activated carbon membranes prepared in this study are shown as promising candidate membrane for separation of VOCs.

A Development of Mechanism on Supply Chain Information Recognition among intelligent equipment for USN based construction supply chain management process (차세대 지능형 건설물류관리 프로세스 지원을 위한 지능형 장비 간 물류정보인식 메커니즘 개발)

  • Kwon, Sang-Hyuk;Shin, Tae-Hong;Chin, Sang-Yoon;Kim, Yea-Sang;Kwon, Soon-Wook
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2008.11a
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    • pp.763-766
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    • 2008
  • The success of a construction project depends on efficient construction supply chain and service informationalization as types and quantities of materials in construction industry geometrically increase because the size of the construction industry increasingly becomes huge, high-rise, and complex. However, the omission of data for each step and the lower effect occurs because of uncertainty and inaccuracy of information as compared to other industries. In addition, it takes many hours to manage the present material states. Currently, IT technology and various mobile devices are being developed through the automation system of next generation intelligent construction supply chain management for the effective supply chain information management but the confusion regarding the recognition and transmission of the supply chain information between the multiple materials and transportation equipment using the IT and wireless network technology occurred. Therefore, the objective of this study is to propose the recognition mechanism which can deduce processes which caused the confusion of the recognition and transmission with supply chain information and solve the problems originated from the processes so as to solve the problems related to the confirmation and the communication of the correct supply chain information.

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3D Digital Design Optimization Process Considering Constructability of Freeform Structure (비정형 구조물의 시공성을 고려한 3차원 디지털 설계 최적화 프로세스)

  • Ryu, Han-Guk
    • Korean Journal of Construction Engineering and Management
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    • v.14 no.5
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    • pp.35-43
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    • 2013
  • Nowadays the widely used media in architecture include visualizations, animations and three-dimensional models. 3D digital methods using active CAM(Computer Aided Manufacturing) and CNC(Computerized Numerical Control) imaging have been developed for accurate shape and 3D measurements in freeform buildings. In contrast to a conventional building using auto CAD system and others, the proposed digital optimization method is based on a combination of 3D numerical data and parametric 3D model for design and construction. The objective of this paper is therefore to present digital optimization process for constructability of freeform building. The method can be useful in the effective implementation of an error-proofing process of freeform building during design and construction phase. 3D digital coordinate data can be used effectively to identify correct size of structural and finish members and installation location of each members in construction field. In addition, architects, engineers and contractors can evaluate design, materials, constructability and identify error-proofing opportunities. Other project participants can also include representatives from all levels of management, departments as well as workers and key subcontractors' personnel, if necessary. The 3D digital optimization process is therefore appropriate to serious variations in freeform shape. For future study, the developed digital optimization method is necessary to be carried out to verify the robustness and accuracy for constructability in construction field.