• Title/Summary/Keyword: Semipermeable

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Simulation Study on the Efficacy of Toxin Removal by Pulsatile Flow in Blood Purification Systems that use Semipermeable Membranes

  • Lim, Ki-Moo;Shim, Eun-Bo
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1655-1659
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    • 2008
  • Using numerical models, we investigated the efficiency of toxin removal using pulsatile flow in blood purification systems that use semipermeable membranes. The model consisted of a three-compartmental mass transfer model for the inside body and a solute kinetics model for the dialyzer. The model predicted the toxin concentration inside the body during blood purification therapy, and the toxin removal efficiencies at different flow configurations were compared quantitatively. According to the simulation results, the clearances of urea and ${\beta}_2$ microglobulin (B2M) using a pulsatile pump were improved by up to 30.9% for hemofiltration, with a 2.0% higher urea clearance and 4.6% higher B2M clearance for high flux dialysis, and a 3.9% higher urea clearance and 8.2% higher B2M clearance for hemodiafiltration. These results suggest that using a pulsatile blood pump in blood purification systems with a semipermeable membrane improves the efficacy of toxin removal, especially for large molecules and hemofiltration treatment.

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Analysis of Types on Osmotic Pressure and Semipermeable Membrane Concept in Chemistry and Biology Textbooks (화학과 생물 교과서에서 삼투압과 반투막 개념에 관한 설명 유형 분석)

  • Ko, Young-Hwan;Kang, Dae-Hun;Ryu, Oh-Hyun;Paik, Seoung-Hey
    • Journal of The Korean Association For Science Education
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    • v.22 no.3
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    • pp.444-454
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    • 2002
  • In this study, we analyzed the explanation of the concepts related to osmotic pressure and semipermeable membrane that were represented in chemistry and biology textbooks of high school and general course of college. There were 4 types of explanation in osmotic pressure and 3 types of semipermeable membrane concept. Students can understand the concepts with different meaning because there are different viewpoints on the explanations of the concepts. We must consider the various types of explanation when we design science textbooks because these confusions disturb students' understanding of the concepts.

Shelf Life Prediction for Packaged Produce Sensitive to Moisture Damage (수분손상에 민감한 포장된 제품의 저장수명 예측)

  • Lee, Chong-Hyun
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.4 no.1
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    • pp.23-32
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    • 1997
  • The change in moisture content of moisture sensitive products in moisture-semipermeable packages was investigated for the purpose of predicting the shelf life of a product-package combination. A mathematical model, and a computer program based on the physiochemical properties of the product and the moisture permeability of the package was developed. The moisture content for products in moisture-semipermeable packages was determined under various environmental conditions and the results were compared with the predicted values by means of the simulation model. These experimental studies demonstrated that the prediction of the change in moisture content of packaged products over time by the simulation model is accurate, within a practical range of temperature and relative humidity values. The developed semi-empirical model is considered to have applications in industry, since it provides product shelf life information for a range of temperature and relative humidity conditions, with a limited number of experimentally obtained data points.

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Variation of Viability and Infectivity of Cryptosporidium Exposed to River Environments During Winter (동절기 자연수계 환경에 노출된 크립토스포리디움의 활성 및 감염성 변화)

  • Park, Sang-Jung;Jung, Il-Jin
    • Journal of Environmental Health Sciences
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    • v.34 no.5
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    • pp.382-386
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    • 2008
  • This study was designed to establish the time frame of viability and infectivity of Cryptosporidium, when the Cryptosporidium is discharged to the aquatic environment. Changes in viability and infectivity of Cryptosporidium in relation to temperature and pH were investigated during winter (Dec 05-Feb 06) using semipermeable cellulose tubes containing infective Cryptosporidium. Infectivity was maintained at 50% after 30 days and almost completely lost after 50 days. It was also established that viability was maintained at about 8% after 90 days.

The Effect of Acetophenone on the Dyeing of Silk (견섬유의 염색에 있어서 아세토페논의 영향)

  • 김태경;임용진;박태수
    • Textile Coloration and Finishing
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    • v.10 no.5
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    • pp.56-62
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    • 1998
  • In the prior study, the dyeing behaviors of Milling Cyanine 5R on silk fiber in aqueous dyeing liquor including small amount of organic compounds were investigated. The most effective compound was acetophenone which increased dye uptake as well as dyeing rate. In this study, the role of the acetophenone in dyeing of silk with Milling Cyanine 5R was studied. By addition of acetophenone into the dye solution, the molar absorptivity of Milling Cyanine 5R increased, and the wavelength of maximum absorption was shifted to longer wavelength, namely bathochromic shifted. This shows that the acetophenone prevents the dye to aggregate, and increases the number of monomeric dye molecule relative to the dye solution without acetophenone. This fact was also confirmed by the increase of the permeation rate of the dye through cellulose semipermeable membrane from the dye solution including the acetophenone. From these results, the acetophenone acts as a prohibitor of dye aggregation, increases the number of monomeric dye molecules even at relatively low temperature, and makes the dyes penetrate into the fiber easier.

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Use of New Passive Sampler to Assess PAHs Contamination (새로운 생물농축 기법에 의한 PAHs의 오염도 확인)

  • 박정규;황인영;문성환;정홍배
    • Environmental Analysis Health and Toxicology
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    • v.16 no.4
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    • pp.171-179
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    • 2001
  • A new passive sampler was developed, improving SPMD (Semipermeable Membrane Devices) that contained triolein in nonporous, low-density polyethylene layflat tubing. Experiments to measure PAHs concentration were carried out at four sites (Dukpo, Sochi, Sohwonggando, Yeonmok) on the southern coast of Korea that were contaminated by oil spills. Passive samplers were deployed at 4 and 8 week intervals at each site. Results showed that bioconcentration levels of PAHs were increased in proportion to exposure duration from all sample sites and accumulation in the passive sampler was much higher than in biota at the Dukpo site. Results of these tests suggest that new passive sampler is a useful tool for measuring bioconcentration organic compounds in aquatic environments.

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A Suppressive Effect of Dietary Fiber on in Vitro Absorption of Lead (납의 In Vitro 흡수에 미치는 식이 섬유의 억제효과)

  • Lee, Su-Rae;Lee, Kyung-Sook
    • Korean Journal of Food Science and Technology
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    • v.21 no.1
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    • pp.63-67
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    • 1989
  • In order to examine the suppressive effect of dietary fiber toward the intestinal absorption of lead, an in vitro absorption test using a semipermeable membrane was undertaken. Among dietary fiber components, cellulose showed no suppressive effect, guar gum and carboxymethyl-cellulose, a slight effect whereas citrus pectin and sodium alginate exhibited a remarkable effect. Among fibrous foods tested, rice bran, wheat bran, Chinese cabbage, radish and tangle had a higher suppressive effect while mandarin orange, apple and laver showed a lower effect.

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Design and Optimization of Solid Dispersed Osmotic Pump Tablets of Aceclofenac, A Better Approach to Treat Arthritis

  • Edavalath, Sudeesh;Rao, B. Prakash
    • Journal of Pharmaceutical Investigation
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    • v.41 no.4
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    • pp.217-225
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    • 2011
  • The aim of this work was to prepare porous osmotic pump tablets for controlled delivery of Aceclofenac. Aceclofenac solid dispersion was prepared to improve the solubility by using the drug - carrier (Mannitol) ratio of 1:1. The osmotic pump tablets were prepared using the solid dispersed product of Aceclofenac. The formulation contains potassium chloride as osmotic agent, cellulose acetate as semipermeable membrane, poly ethylene glycol (PEG 4000) as pore former and sodium lauryl sulphate (SLS) as solubility enhancer. The formulations were designed by the general factors such as osmotic agent and pore former. All formulations were evaluated for various physical parameters and, the in vitro release studies were conducted as per USP. The drug release kinetic studies such as zero order, first order, and Higuchi and Korsmeyer peppas were determined and compared. All the formulations gave more controlled release compared to the marketed tablet studied. Numerical optimization techniques were applied to found out the best formulation by considering the parameter of in vitro drug release kinetics and dissolution profile standards. It was concluded that the porous osmotic pump tablets (F7) composed of Aceclofenac solid dispersion/Potassium chloride/Lactose/Sodium lauryl sulphate/Magnesium Stearate (400/40/95/10/5, mg/tab) and coating composition with Cellulose acetate/ PEG 4000 (60/40 %w/w) is the most satisfactory formulation. The porous osmotic pump tablets provide prolonged, controlled, and gastrointestinal environment-independent drug release.

Preparation and Release Characterization of Osmotic Granule Nifedipine Delivery System (니페디핀 삼투성 과립 시스템의 제조와 약물 방출 특성)

  • Jeong, Sung-Chan;Cho, Young-Ho;Lee, Soo-Young;Lee, Bong;Kim, Moon-Suk;Kang, Gil-Son;Lee, Hai-Bang
    • Journal of Pharmaceutical Investigation
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    • v.36 no.1
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    • pp.11-17
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    • 2006
  • The objective of this study was to confirm the effect of the type of dissolution media and paddle speed on nifedipine (ND) release profile from osmotic granule and the storage stability. Osmotic granule was manufactured by fluidized bed coating method. At each coating step, morphology of osmotic granule was differed. The size of osmotic granule was $750\;{\mu}m$ at 3 wt% membrane thickness. ND release was changed in diverse dissolution media, paddle speed. ND release is governed by not only osmotic pressure but diffusion from osmotic granule. ND release from osmotic granule decreased as storage period increased. These may be caused by liquid excipient which has low molecular weight. Storage stability of osmotic granule could be improved by removing liquid excipient from semipermeable membrane.

Physical and Strength Properties of Frankincense Resin Treatment Paper (유향수지 처리지의 물리 및 강도적 특성)

  • Kim, Jong-Min;Yoon, Seung-Lak;Jo, Jong-Soo
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.46 no.6
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    • pp.26-33
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    • 2014
  • Frankincense resin was applied to Hanji to improve its physical properties. The resin-treated paper showed the increasement of physical properties such as weight, thickness, and density. The highest increasement in weight and density of resin-treated paper were found at 30% treatment concentrations and the largest values of density were $41g/m^2$ Hanji. With the increasement of concentration, the brightness was decreased and transparency was improved. Of the mechanical properties of the paper, the tensile index and burst index showed the improved values. The tear index, however, was decreased. The frankincense resin showed the highest result in the tensile index of resin-treated paper and the basis weight of $41g/m^2$ Hanji. The air resistance of the resin-treated paper got improved with the increase of the concentration and $105g/m^2$ Hanji showed the highest values. The highest improvement in air resistance may make the resin-treated Hanji possible to use for semipermeable materials.