• Title/Summary/Keyword: Aqueous system

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A Study on Dyeing Properties of Nylon 6 Fabrics in Supercritical Fluid Dyeing System (I): Depending on Temperature and Pressure (Nylon 6 섬유의 초임계 유체 염색특성 연구 (I): 온도, 압력의 변화)

  • Ko, Eunhee;Lee, Inyeol;Kim, Changil
    • Textile Coloration and Finishing
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    • v.32 no.2
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    • pp.80-88
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    • 2020
  • Supercritical fluid dyeing is a new alternative to the conventional aqueous process because of its environmental benefits. In this study, dyeing properties of Nylon 6 fabrics were investigated depending on dyeing temperature and pressure in supercritical CO2 fluid dyeing system. In order to select the optimal condition for supercritical fluid dyeing of Nylon 6 fabrics, dyeing temperature and pressure were varied from 100, 110, 120℃, 200, 230, 260bar, respectively. The results of K/S values and levelling properties showed that the optimal dyeing condition for Nylon 6 fabrics was 110℃ and 230bar in the supercritical CO2 fluid dyeing system. The washing fastness ratings of the dyed Nylon 6 fabrics under supercritical medium were good for both fading and staining except for staining on nylon.

Stueies on the Occurrence of Seedling Rot of Burley Tobacco Transplants Caused By Pyhium spp. and Its Control Measures in Field. (버어리종 담배 포장에서의 가칭 담배 묘썩음병(Pythim spp.) 발생 및 방제에 관한 연구)

  • 강여규
    • Journal of the Korean Society of Tobacco Science
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    • v.13 no.1
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    • pp.53-60
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    • 1991
  • Seedling rot occurred on burley tobacco at the early growing stage after transplanting was surveyed in the Chonbuk province, the main area for burley tobacco production, during the 3 crop years from 1986. The incidence of disease was about 0.6-0.7% every year and major causal organisms were Pythium spp. More diseased plants were observed in the fields in which tobacco planted with improved mulching system than in that with any other mulching system. The temperature and relative humidity in the planting hole covered with polyethylene film for 11 days after transplanting were recorded by 27-45$^{\circ}C$ and 75~95%, respectively. The punched polyethylene film mulching field showed less diseased plants than that with improved mucking. In improved mulching system the longer period of mulching caused higher incidence of seedling rot(r=0.74**). Soil drench treatment of 200m1 of aqueous Metalaxyl Solution(125ppm) was effective to control the disease.

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Parenteral Docetaxel Emulsion System and Its Stability

  • Kim, Hyun-Jo
    • Journal of Pharmaceutical Investigation
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    • v.39 no.1
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    • pp.13-18
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    • 2009
  • Docetaxel is an anticancer agent with low aqueous solubility. More extensive clinical use of this drug is somewhat delayed due to lack of appropriate delivery vehicles. An attempt was made to adopt an o/w emulsion as the drug carrier which incorporated docetaxel in the propyleneglycerol stabilized by a mixed-emulsifier system. A suitable formulation was found in this study: 10 mg/mL docetaxel, 10% (w/v) oil blend, 4% (w/v) PG, 3% (w/v) Solutol HS 15 in 2.25% (w/v) glycerol solution. The formulated emulsion has very good stability when stored at $40^{\cird}C$, and the docetaxel containment efficiency can be maintained above 95% and the mean emulsion diameter around $10{\mu}m$ for at least 3 months. The formulated emulsion is a promising carrier for docetaxel and other lipophilic drugs.

Central nervous system depressant effect of hot water extract of Ocimum sanctum Linn. (Labiateae)

  • Alamgir, Mahiuddin;Choudhuri, Shahabuddin Kabir;Jabbar, Shaila;Rajia, Sultana;Khan, Mahmud Tareq Hassan
    • Advances in Traditional Medicine
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    • v.2 no.2
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    • pp.101-105
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    • 2002
  • A battery of neuropharmacological experiments showed the hot water extract of Ocimum sanctum Linn. (Labiateae) had a depressant effect on the central nervous system (CNS), but the aqueous extract showed no effect on it. The hot water extract reduced the spontaneous locomotor activity, exploratory head dipping, propulsive locomotion and exploratory ambulation as well as prolonged the pentobarbital induced sleeping time. The depressant effect starts from 60 minutes after the drug administration and continued to 180 minutes. The drug may exert central depressant effect by interfering with the function of the cortex.

Using Polypyrrole for Drug Delivery System (폴리피롤을 이용한 약물전달시스템)

  • Lee, Sang-Jo;Lee, Seung-Ki;Oh, Myung-Hwan;Park, Jung-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.11a
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    • pp.448-451
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    • 2002
  • The possibility of using polypyrrole as a drug delivery system(DDS) has been studied using indicate (Phenol red) and substance with therapeutic activity(Sodium salicylate). In aqueous solution, negative potential is applied to polypyrrole then anion(with therapeutic activity) of sodium salicylate is released by redox processes of polypyrrole. The release amount of anionic drugs from polypyrrole is measured by UV-visible spectrometer which can measure UV-absorbance of materials. Electrode area that use for release amount measurement is$50mm^{2}(5{\times}10mm)$,and thickness of polypyrrole membrane is $15{\mu}m$. DC 1V applied in saline solution, the release amount according to time increased gradually. In various electrode area, release amount of anionic drug is directly to electrode area.

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Enhanced Removal of Phenol from Aquatic Solution in a Schorl-catalyzed Fenton-like System by Acid-modified Schorl

  • Xu, Huan-Yan;Prasad, Murari;Wang, Peng
    • Bulletin of the Korean Chemical Society
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    • v.31 no.4
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    • pp.803-807
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    • 2010
  • Schorl modified by $H_2SO_4$ has been successfully developed to enhance schorl-catalyzed Fenton-like reaction for removal of phenol in an aqueous solution. The phenol removal percentage can be increased from 4% to 100% by the system of modified schorl and $H_2O_2$. Batch experiments indicate that the percent increases in removal of phenol by increasing the dosage of catalyst, temperature and initial concentration of $H_2O_2$. The results of XRD, FT-IR and SEM suggest that no new phases are formed after removal of phenol by modified schorl. ICP-AES results reveal that more dissolution of iron results in higher catalytic oxidant activity in the system of modified schorl and $H_2O_2$. Besides minor adsorption, mineral-catalyzed Fenton-like reaction governs the process.

Effect of Zeta-Potential on the Viscosity of Clay-Water Suspension

  • Lee, Young-Seek;Ree, Jong-Baik;Ree, Taik-Yue
    • Bulletin of the Korean Chemical Society
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    • v.3 no.3
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    • pp.83-88
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    • 1982
  • Viscosity and zeta-potential of 11.0 wt. % aqueous bentonite suspension containing various electrolytes and hydrogen-ion concentration were measured by using a Couette type automatic rotational viscometer and Zeta Meter, respectively. The effects of pH and elcctrolytes on the rheological properties of the suspension were investigated. A system, which has a large zeta-potcntial, has a small intrinsic relaxation time ${\beta}$ and a small intrinsic shear modulus $1/{\alpha}$ in the Ree-Eyring generalized viscosity equation, i.e., such a system has a small viscosity value, since ${\eta}={\beta}/{\alpha}$. In general, a stable suspension system has large zeta-potential. The stability condition of clay-water suspension can be estimated by viscometric method since stable suspension generally has small viscosity. The correlation between the stability, viscosity and zeta-potential has been explained by the Ree-Eyring theory of viscous flow.

Molecular Conformation and Non-Newtonian Viscosity Behavior of Poly(L-proline) in Various Solvent Systems

  • Jang, Chun-Hag;Kim, Hyun-Don;Lee, Jang-Oo
    • Bulletin of the Korean Chemical Society
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    • v.15 no.5
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    • pp.399-404
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    • 1994
  • The non-Newtonian viscosities (the specific or intrinsic viscosities) of poly(L-proline) (PLP, $M_v$=19,000 and 32,000) in various mixed-solvent systems like water-propanol and acetic acid-propanol of varying compositions were measured during the reverse mutarotation (Form II ${\rightarrow}$Form I) by the application of external pressure (up to 4.5 psi). The non-Newtonian viscosity effect was found to be larger in acetic acid-propanol system than in water-propanol system and to somewhat decrease during the reverse mutarotation at a given solvent system. The non-Newtonian viscosity behavior of PLP in aqueous salt ($CaCl_2$) solution was also studied, from which it was found that the degree of the non-Newtonian effect decreased with increasing salt concentration, and increased with increasing PLP molecular weight. These findings could be explained in terms of conformational changes of PLP in solution (like the helix-helix or helix-coil transition) involved.

A Study on the Heat Transfer Characteristics of Slurry Ice Generator using Scraper (스크레퍼형 슬러리아이스 제빙기의 열전달 특성 연구)

  • Kim, Joung-Ha;Yun, Jae-Ho;Kim, Min-Jun;Kim, Kyu-Jin;Cho, Hyoug-Seok;An, Seong-Kuk
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.144-149
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    • 2006
  • In this study ice making characteristics are experimentally investigated for the ice slurry generating system which is pneumatically operated. The experimentations are conducted under the various test conditions such as chilled water inlet temperature, aqueous solution concentration, flow rate of cooling water, scraper pitch and frequency of cylinder stroke. For the above experimental conditions, ice making characteristics of the slurry ice generating system are evaluated in terms of the overall heat transfer coefficient, heat transfer rate and the amount of slurry ice generation. And the experimental results show that the heat transfer rate of the system increases as the flow rate of cooling water solution increases and the concentration of ethylene glycol and inlet temperature of chilled water decreases.

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Inhibition of Cytopathic Effect of Human Immunodeficiency Virus-1 by Water-soluble Extract of Ganoderma lucidum

  • Kim, Ha-Won;Shim, Mi-Ja;Choi, Eung-Chil;Kim, Byoung-Kak
    • Archives of Pharmacal Research
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    • v.20 no.5
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    • pp.425-431
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    • 1997
  • To examine components of Ganoderma lucidum for anti-human immunodeficiency virus (HIV) activity, the aqueous extracts of its basidiocarps were separated into high-molecular-weight (HMF) and low-molecular-weight (LMF) fractions. These fractions were used in XTT [2,3-bis (2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide] antiviral assay which can quantitatively measure cytopathic effects of HIV-1 on CEM, human T lymphoblastoid cell line. The CEM cell line added with serial diluted HMF or LMF was cultured in the absence or presence of HIV-1. The results showed that the LMF of the aqueous extract strongly inhibited cytopathic effect of the target cell induced by HIV-1. When two-fold serially diluted LMF ranging from $40.97{\mu}g/ml$4 to 125.00 .mu.g/ml was added to the virus-free culture system, no toxicity on the target cells was detected in all the concentrations tested. However, when it was added to the HIV-infected culture system, the viabilities of the target cell reached a plateau recovering its viabilities to 71.7% and 82.5% in experiment-1 and -2 at 15.60 .mu.g/ml, respectively. The cell viabilities were then gradually decreased but maintained at more than 50% above 31.20 .mu.g/ml concentration. On the contrary, HMF did not prevent any HIV-induced cytopathic effect at any concentrations tested on this cell line. From these results, negligible toxicities were observed by both HMF and LMF of G. luciolum, and recovery of cell viability in HIV infected target cell was induced only by LMF of the carpophores.

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