• Title, Summary, Keyword: 용해도

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Effect of Molecular Structures on the Solubility Enhancement of Organic Contaminants by Amphiphiles (양수성 물질에 의한 유기오염물질의 수중 용해도 증가에 분자구조가 미치는 영향)

  • Cho, Hyun-Hee;Park, Jae-Woo
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.4
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    • pp.755-764
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    • 2000
  • Fate and transport of hydrophobic organic contaminants can be influenced by naturally-existing humic substances and surfactants applied to wash polluted soils in the subsurface environment. The objective of this paper is to study the solubility enhancement of four PAHs (polycyclic aromatic hydrocarbon) and p,p'-DDT in humic acid and surfactant solutions. As the number of aromatic ring is increased, the extent of solubility enhancement of PAHs by humic acid increased. Although the hydrophobicity of p,p'-DDT was the largest among five organic compounds used, the extent of solubility enhancement of p,p'-DDT by humic acid was lower than that of pyrene. In case of anionic surfactants, the extent of the increased solubility of five organic compounds by SDS and SDDBS was increased linearly, but the extent of the increased solubility of p,p'-DDT by MADS-12 was lower than that of perylene.

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Effect of Surfactant Molecules on the Aqueous Solubility of two PAHs (새로운 계면활성제들에 의한 두 PAH의 수중 용해도 증가)

  • 이진희;박재우
    • Journal of Korea Soil Environment Society
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    • v.5 no.1
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    • pp.65-73
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    • 2000
  • Surfactants have been extensively considered for decontamination of the subsurface polluted with hydrophobic organic compounds. In order to investigate the effect of molecular structures on the solubilization of hydrophobic organic compounds, solubility enhancement of two PAHs in solutions of three different surfactants-conventional, dianionic, and gemini. The batch experimental results showed that the gemini was the most effective and the dianionic was the least, indicating that organic carbon content of the surfactants was the major factor which determines the sorption capacity of surfactant aggregates in water, unlike some of the previous reports.

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제어용 교류 전동기의 기술동향

  • 이광원
    • 전기의세계
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    • v.34 no.4
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    • pp.220-224
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    • 1985
  • 제어용 전공기에 관한 외국의 활발한 연구개발 노력에 비하여 우리나라 전동기 산업은 아직까지 전력용 전동기 위주였고, 대학에서의 교육도 전력용 전동기의 원리에 관한 것이었다. 이것은 전력용 전동기가 산업용으로 기본적이고 필수적이기 때문이다. 그러나, 정보산업의 발전과 자동화의 추세에 따라 제어용 전동기의 이용과 보급이 격증하고 있고 우리산업도 선진국 대열에 진입해야 할 단계에 있으므로, 첨단산업 분야의 제어용 전동기 기술에 대한 연구가 시급하다고 생각된다.

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Solubilities of Naphthalene in Supercritical Fluids (초임계 유체내의 나프탈렌의 용해도)

  • Jeong-Rim Kim;Ho-Kun Kim;Jin-Burm Kyong
    • Journal of the Korean Chemical Society
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    • v.32 no.4
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    • pp.311-317
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    • 1988
  • The solubilities of naphthalene in ammonia could be measured at various temperatures and pressures above the critical point of ammonia to represent the relationship between the solubility and the density of ammonia at desired temperature and pressure by means of a simple equation. This equation allows a calculation of the solubilities at higher and lower pressures. Using the equation, the solution energies, the solution entropies, and the second cross virial coefficients between naphthalene and ammonia have been determined to be compared with those in the case of the dissolution of naphthalene in supercritical carbon dioxide.

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Vehicle Impact Simulation of Composite Safety Barriers (복합소재 방호울타리의 차량 충격 시뮬레이션)

  • Kim, Seung-Eock;Jeon, Shin-Youl;Hong, Kab-Eui
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.413-416
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    • 2010
  • 본 연구에서는 복합소재 교량용 방호울타리를 개발하여 컴퓨터 시뮬레이션을 통해 강재 교량용 방호울타리와 복합소재 교량용 방호울타리의 성능을 비교하였다. 구조적 강도 성능 측면에서 복합소재 교량용 방호울타리의 경우 교량용 방호울타리의 변형이 31.7%로 감소하여 강재 교량용 방호울타리 보다 강도 성능이 우수하였다. 탑승자 보호 성능 측면에서, 복합소재 교량용 방호울타리는 THIV 47.1%, PHD 49.0%로 감소하여 강재 교량용 방호울타리 보다 탑승자 보호성능이 우수하였다. 충돌 후 차량의 거동 측면에서, 복합소재 교량용 방호울타리는 이탈속도가 증가하고 이탈각도가 감소하여 강재 교량용 방호울타리 보다 충돌 후 차량의 거동이 우수하였다. 교량용 방호울타리의 비산 측면에서, 강재 및 복합소재 교량용 방호울타리는 비산이 발생하지 않았다.

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Solubility of Carbon Dioxide in Poly(ethylene glycol) Dimethyl Ether (Poly(ethylene glycol) Dimethyl Ether에 대한 이산화탄소의 용해도)

  • Lee, Eun-Ju;Yoo, Jung-Deok;Lee, Byung-Chul
    • Korean Chemical Engineering Research
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    • v.55 no.2
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    • pp.230-236
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    • 2017
  • Solubility data of carbon dioxide ($CO_2$) in poly(ethylene glycol) dimethyl ether (PEGDME) are presented at pressures up to about 50 bar and at temperatures between 303 K and 343 K. The solubilities of $CO_2$ were determined by measuring the bubble point pressures of the $CO_2+PEGDME$ mixtures with various compositions using a high-pressure equilibrium apparatus equipped with a variable-volume view cell. To observe the effect of the PEGDME molecular weight on the $CO_2$ solubility, the $CO_2$ solubilities in PEGDME with two kinds of molecular weight were compared. As the equilibrium pressure increased, the $CO_2$ solubility in PEGDME increased. On the other hand, the $CO_2$ solubility decreased with increasing temperature. When compared at the same temperature and pressure, the PEGDME with a higher molecular weight gave smaller $CO_2$ solubility on a mass fraction and molality basis, but gave greater $CO_2$ solubilities on a mole fraction basis.

A Case Study on the Visually Impaired Elementary Students' Conception of Dissolution (시각장애 초등학생의 용해 개념에 대한 사례 연구)

  • Kim, Hak Bum;Baek, Sangsu;Cha, Jeongho
    • Journal of the Korean Chemical Society
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    • v.57 no.4
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    • pp.507-514
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    • 2013
  • In this study, the characteristics of visually impaired elementary students' conceptions on dissolution were investigated. The semi-structured interviews about phenomenon of dissolution, uniformity of solution, conservation of mass on dissolving and volume change during dissolving were conducted with 4 fifth-grade elementary students with visual impairments (three were blind, and one had low-vision). Interviews were recorded and the data were analyzed after transcription. As a result, students with visual impairments knew well about the phenomenon of dissolution, uniformity of solution, and conservation of mass on dissolving, while they couldn't explain volume change during dissolving. Although students with visual impairments were found to have similar level of understanding with students without visual impairments, they had sounder understanding about uniformity of solution. However, students with visual impairments had superficial understanding based on phenomenal experiences. Some of students with visual impairments tried to give micro-level explanation. Based on these results, educational implications were discussed.

Solubility Measurement of Carbon Dioxide in Alkylcarbonates and Triacetin at High Pressure (고압에서 알킬카보네이트와 트리아세틴의 이산화탄소 용해도 측정)

  • Kim, Ji Won;Hong, Won Hi;Hong, Yeon Ki
    • Clean Technology
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    • v.21 no.2
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    • pp.124-129
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    • 2015
  • The constant-volume method was used to determine the solubility of CO2 in various physical absorbents such as DMPEG (dimethyl ether of polyethylene glycol), DEC (diethyl carbonate), DMC (dimethyl carbonate), and TAT (triacetin) in the total pressure range from 5 to 30 bar. The Peng-Robinson equation of state has been used to describe the equilibrium behavior of these mixtures. It was found that the solubility of absorbents was in the of DMPEG250 > TAT > DEC > DMC at the same temperature. Futhermore, the solubiity of blended absorbent of DMPEG250 and DEC is higher than that of DMPEG 250 alone. Therefore, blended absorbent of DMPEG250 and DEC is expected to be an effective and low cost absorbent for physical absorption in precombustion CO2 capture.

Prediction of Affinity between Membrane and Esters Using Solubility Parameter (용해도 파라미터에 의한 막과 esters 간의 친화도 예측)

  • Song, Kun-Ho;Lee, Kwang-Rae
    • Membrane Journal
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    • v.24 no.6
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    • pp.484-490
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    • 2014
  • To find out the feasibility of the separating/enriching esters from aqueous solution using FASs (Fluoloalkyl-silanes-coupling agent)-surface modified hydrophobic membrane, the solubility parameter of FASs was obtained and compared with those of esters and water. The value of the solubility parameter of FASs (${\delta}_t=16.9$) was almost same with those of esters (ethyl acetate ${\delta}_t=18.1$, propyl acetate ${\delta}_t=18.0$, ethyl propionate ${\delta}_t=17.9$, butyl acetate ${\delta}_t=17.4$, ethyl butyrate ${\delta}_t=17.0$). However, the calculated value of the solubility parameter of water was ${\delta}_t=47.8$, which was far from the value of the solubility parameter of FASs (${\delta}_t=16.9$). This means that the FASs-modified membrane has a much higher affinity to esters than water. The experimental results of permeation flux of esters used in this study showed that the order of permeation flux predicted by the solubility parameter was almost coincide with experimental results. It might be concluded that the solubility parameter may be applicable for a separating/enriching flavors from aqueous natural-flavor solution, in which esters are main components of natural flavors.