간행물
한국응용과학기술학회지 KCI 등재 The Korean Society of Applied Science and Technology
- 발행기관 한국응용과학기술학회(구 한국유화학회)
- 자료유형 학술지
- 간기 격월간
- ISSN 1225-9098 (Print)2288-1069 (Online)
- 수록기간 1984 ~ 2024
- 주제분류 공학 > 화학공학 공학 분류의 다른 간행물
- 십진분류KDC 575DDC 665
권호리스트/논문검색
Vol.13 No.3 (1996년 11월) 16건
1.
1996.11
구독 인증기관 무료, 개인회원 유료
4,600원
2.
1996.11
구독 인증기관 무료, 개인회원 유료
Essentiality was proposed in the field of lipid by Burr and Burr in 1929. When rats were raised on the fat-free diet, their growth retarded and their skin and tails showed the characteristic deficient symptoms, which were relieved by the addition of Ω6(n-6) polyunsaturated fatty acids as linoleic(LA) and arachidonic(AA) acids to the basal diet. LA is dehydrogenated to γ-linolenic acid(GLNA) by δ6 desaturase, then GLNA is 2 carbon chain elongated by elongase to dihomo-γ-linolenic acid(DGLNA), which is desaturated by δ5 desaturase to AA. These acids are called LA family or Ω6(n-6) polyunsaturated fatty acids(PUFA). α-Linolenic acid(ALNA) is converted through the series of desaturation and elongation steps to docosahexaenic acid(DHA) via eicosapentaenoic acid(EPA). These acids belong to ALNA family or Ω3(n-3)PUFA. Human who consume large amounts of EPA and DHA, which are present in fatty fish and fish oils, have increased levels of these two fatty acids in their plasma and tissue lipids at the expense of LA and AA. Alternately, vegetarians, whose intake of LA in high, have more elevated levels of LA and AA and lower levels of EPA and DHA in plasma lipids and in cell membranes than omnivores. AA and EPA are metabolized to substances called eicosanoids. Those derived form AA are known as prostanocids(prostaglandins and prostacyclins) of the 2-types and leukotrienes of the 4-series, whereas those derived from EPA are known as prostanoids of the 3-types and leukotrienes of the 5-series. DGLNA is a precursor of the 1-types of prostaglandins. The metabolites of AA and EPA have competitive functions. Ingestion of EPA from fish or fish oil replaces AA from membrane phospholipids in practically all cells. So this leads to a more physiological state characterized by the production of proatanoids and leukotrienes that have antithrombic, antichemotactic, antivasoconstrictive and antiinflammatory properties. It is evident that Ω3 fatty acids can affect a number of chronic diseases through eicosanoids alone.
4,000원
3.
1996.11
구독 인증기관 무료, 개인회원 유료
We have synthesized the water-insoluble chitosan derivative, N-dithiocarboxy chitosan sodium salt, through the reaction of chitosan with carbon disulfide in the presence of alkali metal hydroxide, Chitosan itself has been prepared using chitin, one of the most abundant compounds in nature, as a starting material. To elucidate this natural polymer the capacity of adsorbing heavy metal ions, we have performed adsorption experiments using chitosan derivatives of various average molecular weights with different contents of sulfur. The effect of pH, adsorption time and temperature on adsorption efficiency was also studied. The adsorbent derived from chitosan of average molecular weight ranging 5,700~20,000 was shown to have the highest capacity of adsorbing heavy metal ions. Adsorbing efficiency was increased as the reaction time was increased and as the reaction temperature range of 25~45℃. The adsorption capacity at various pH, however, appeared to vary depending on the heavy metal ions studied.
4,000원
4.
1996.11
구독 인증기관 무료, 개인회원 유료
In this paper, intermediate cyan coupler was prepared by the reaction of 2-nitro-4, 6-dichloro-5-methylphenol with Pd(5wt%). The product was identified by using various analytical tools such as melting point, elemental analyzer, IR spectrophotometer and mass spectrometer. The reaction of intermediate cyan coupler with CD-3(color development agent) was shown cyan color.
4,000원
5.
1996.11
구독 인증기관 무료, 개인회원 유료
Metachromatic properties of admixture of thionine and methylene blue(MB) in aqueous solution and phospholipid bilayer membrane have been studied by absorption spectroscopy. When thionine and MB were mixed, new coaggregate has been formed because of MB was redistributed to thionine aggregate. In phosphlipid bilayer membrane system, the highly concentrated thionine was easily formed the coaggregation with MB moiety independent of MB concentration, and absorption band of admixture were more transferred to short wavelength than aqueous system. In monomeric thionine concentration, the coaggregation band was observed at the middle wavelength between the site of monomeric thionine and the site of dimeric MB in the presence of lipid bilayer membrane.
4,000원
6.
1996.11
구독 인증기관 무료, 개인회원 유료
A new one series of chiral schiff's base containing benzylidene aniline moieties was synthesized and characterized by IR, 1H NMR. elementary analysis, and polarized optical microscopy(POM). The yield of these synthetic compounds was in the range of 62~67℃. The results showed that most of the synthetic compounds were monotropic liquid crystal and exhibited chiral smectic C(Sc*) liquid crystal phases, and the range of phase transition temperature was to 71.4℃ from 45.0℃.
4,000원
7.
1996.11
구독 인증기관 무료, 개인회원 유료
In acid-catalyzed acetal cyclization of long aliphatic aldehydes(R=n-C7H15 ; n-C9H19 ; n-C11H23) with 1,1,1-tris(hydroxymethyl)propane, 2-alkyl-5-hydroxymethyl-5-ethyl-1,3-dioxanes were obtained. The final products, sodium 2-alkyl-5-(sulfonatedpropylethermethyl)-5-ethyl-1,3-propanesultion in the presence of sodium hydride. These compounds were a new group of destructible surfactants which were readily hydrolyzed and oxidized in natural water reservoirs. Physical properties of these new compounds involved some surface properties such as Krafft point(Kp), critical micelle concentration(cmc), surface tension of aqueous solutions near cmc(γmin), foaming power, emulsion power and hydrolysis properties were determined. The destructible surfactants containing 1,3-dioxane ring were synthesized to about 85±5.5% yield. The cmc values of the compounds by ring method were assumed to 0.5~5.0×10-3mol/L range and surface tensions at cmc were 29.5~33.0dyne/cm respectively at 25℃. The foaming power and foam stability were 170~230mm and 52~135mm respectively at 1×10-2mol/L, foam was occurred rarely below 1×10-3mol/L. The emulsion property of liquid paraffin was better than that of soybean oil. For hydrolysis property with ph and time, these compounds were decomposed within about 200minutes at ph1~2. Hopefully these compounds are expected to be a good O/W emulsifier that have decomposability in acid and may be used in the process which do not need foaming.
4,200원
8.
1996.11
구독 인증기관 무료, 개인회원 유료
In this study, sensitizing dye was prepared by the reaction of 2-methyl-3-sulfopropyl-4,5-naphthothiazolium(inner salt) with triethyl orthobenzoate in the presence of triethylamine. The product was identified by using various analytical tools such as elemental analyzer, IR spectrophotometer, UV-Vis spectrophotometer, 1H-NMR spectrometer, TGA and DSC. Therefore, it was concluded that 9-phenyl-3,3'-bis(3-sulfopropyl)-4,5,4',5'-naphthothiazolo carbocyanine triethyl ammonium salt can be used as red-sensitizing dye for the spectral sensitization of photographic emulsion.
4,000원
9.
1996.11
구독 인증기관 무료, 개인회원 유료
EMA-co-DAMA were synthesized from 2-diethylaminoethyl metacrylate and ethylhexyl metacrylate in acrylmonomer. To facilitate water emulsification, acrylic copolymer was cationized by acetic acid to produce acetated acrylic copolymer. The structures of the synthesized copolymer and acetated copolymers were confirmed by IR, NMR, and molecular weight was measure by GPC, and C.H.N elemental analysis. Acetated acrylic copolymers were perfectly emulsified in water and showed increased emulsion stability. Polymer dispersion for cement modifier[(PDCM-PED) water proof agent of cement for concrete in building construction] was prepared by blending of the guaternized acrylic copolymer syndisized above, sodium silicate, sodium gluconate and oleic acid emulsion. The result with prepared polymer dispersion of cement modifier was examined, and it was found that excellent waterprooffing effect ; Water permeability ratio is 0.50 under the water pressure of 100g/cm2 and 0.60 under 3kg/cm2, and water absorption ratio is 0.42~0.50 and 1.0~1.02 compressive strength ratio at mixed of water/PDCM-PED is 50 times.
4,300원
10.
1996.11
구독 인증기관 무료, 개인회원 유료
In the separation of toluene/n-heptane mixture by the emulsion type liquid membrane in an batch system, the effect of surfactant on the separation factor and membrane stability was studied over the surfactant concentration ranging form 0.1 to 1.5wt％ at the contact time of 5 and 10 minutes. and the settling time of 5 and 10 minutes. The surfactant used was sodium lauryl sulfate. The separation factor reached its maximum value at the surfactant concentration of 0.5wt％ for surfantant. It was found that the percentage of membrane breakup reached its minimum values and the separation factor showed its maximum value at the surfactant concentration of 0.5wt%. which confirmed that efficient separation could be effect when emulsion liquid membrane was stable because of low membrane breakup.
4,000원
11.
1996.11
구독 인증기관 무료, 개인회원 유료
It is well known that the metallo- phthalocyanine (MPcs) are sensitive to toxic gaseous molecules such as NO2 and also chemically and thermally stable, Therefore, lots of MPcs have been studied for the potential chemical sensor for NO2 gas using quartz crystal microbalance(QCM) or electrical conductivity. In this study, ultra-thin films of octa(2-ethylhexyloxy)copper-phthalocyanine were prepared by Langmuir-Blodgett method and characterized by using UV-VIS absortion spectroscopy and ellipsometry. Transfer condition, and characterization of LB films were investigated and preliminary results of current-voltage(I-V) characteristics of these films exposed to NO2 gas as a function of film thickness and temperature were discussed.
4,000원
12.
1996.11
구독 인증기관 무료, 개인회원 유료
Many alternatives to Trichlorothane & Trichlorotrifluoroethane mainly used as cleaning solvent for industrial parts are developed and commercialized because the solvent is scheduled to phaseout after 1996. Considering there are many kinds of parts and contaminants in all parts cleaning, It is essential to investigating the characteristics and performance of the alternatives prior to use. For the contaminant of a standard oil, waters, hydrocarbon and halogen parts which are the comercially available and promising alternatives were experimented at the same condition of Trichlorothane & Trichlorotrifluoroethane to check the cleaning performance. Overally, the removal efficiency of halogen solvent parts was better than that of hydrocarbon or waters parts for removing the standard oil used in this experiment.
4,000원
13.
1996.11
구독 인증기관 무료, 개인회원 유료
The excess volumes of mixing of benzyl alcohol, ethyl alcohol, halothane, and procaine in vesicle and suspensions of several lipids have been determined at 25℃ using a excess volume dilatometer. The potency of general anesthetics has long been known to be correlated with lipid solubility. Denaturations of the bacteriorhodopsin, which is a sole membrane protein in the purple membrane of Halobacteriun Halobium, were studied by UV/Vis absorption changes. The excess volumes of mixing of benzyl alcohol and procaine in egg lecithin were all found to be negative and this result was confirmed as Miller's supposition.
4,000원
14.
1996.11
구독 인증기관 무료, 개인회원 유료
Thermograms of methylene blue(MB) in L-α-lecithin vesicle and incorporated purple membrane vesicle(InPM) systems have been studied by photochemical reaction differential scanning calorimetry at 25~55℃. Phase transition temperatures of lecithin vesicle, purple membrane(PM), and InPM were found to be independent of illumination of light(436nm) at 39~40℃, but endothermic phase transition was found in InPM vesicle. In MB-InPM system, endothermic phase transition was found on unillumination of light at 40~42℃, but exothermic phase transition was found on steady illumination of light at 48~52℃. It was estimated that the light energy absorbed from MB on vesicular surface was transferred to PM, and the transferred energy was redistributed to hydrophobic site of membrane. Therefore, the exothermic phase transition was measured at high temperature because of the increased hydrophobicity of acyl chain.
4,000원
15.
1996.11
구독 인증기관 무료, 개인회원 유료
Durable softening water repellents such as PODCW, PDDCW, and PEDCW were prepared by blending cationized polymers, fatty carbamide, waxes, and emulsifiers. The cationized polymers included poly (octadecyl methacrylate-co-2-diethylaminoethyl methacrylate) [PODC], poly (n-dodecyl methacrylate-co-2-diethylaminoethyl methacrylate) [PDDC]and poly (2-ethylhexyl methacrylate-co-2-diethylaminoethyl methacrylate) [PEDC]. After the PET fabrics were treated with these water repellents, water repellency, softness, and durability of the PET fabrics were examined by various methods : water repellency by the hydrostatic pressure and the contact angle methods, softness by crease recovery and tearing strength, and durability by washability, respectively. Rating of water repellency of PET fabrics treated with PODCW was 80+, but those treated with PDDCW and PEDCW were not high enough to be used in industry.
4,000원
16.
1996.11
구독 인증기관 무료, 개인회원 유료
Naphthoquinone-1,2-diazide-5-sulfonyl[NDAS] derivatives members of quinone diazide compound that are utilizable as photosensitive polymer material were synthesized, and photoresist were prepared by mixing these derivatives with m-cresol novolak(a matrix resin) at various weight ratios. Photosensitive characteristics of photoresist were studied by examining UV and IR, relative sensitivity using a Gray scale method, and SEM to analyze if they can be used as photosensitive material in printing process. Experimental results showed that, by UV, NDAS derivatives were photoconverted and developer-soluble photoresist were produced. The mixing ratio of 1:4(by mass) of NDAS+p-ydroxybenzophenone+sensitizer and m-cresol novolak gave rise to the highest dissolution rate. In addition, photoresist obtained at this condition resulted in the most superior sensitivity and contrast.
4,000원
