• Clean Technology
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• v.20 no.3
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• pp.205-211
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• 2014

Biomass-based plastics containing the biomass content higher than 25 wt% have been considered as environment-friendly materials due to their effects on the reduction in the $CO_2$ emission and petroleum consumption as well as biodegradability after use. This article described the effect of the additions of oxo-biodegradable additive, 4 kinds of plant biomass, unsaturated fatty acid, citric acid in the properties of polyethylene films. Bio films were prepared using a variety of biomasses and tested for feasibility as a food packaging film. Mechanical properties such as tensile strength and percent elongation at break were evaluated. Husk biomasses from such as corn, soybean, rice, and wheat were pulverized using air classifying mill (ACM) and four different types of packaging films with thickness of $50{\mu}m$ were prepared using the pulverized biomass and low density polyethylene/linear low density polyethylene. The packaging film with wheat husk biomass was found to have greater mechanical properties of elongation and tensile strength than the other samples. Biodegradability of bio film was measured to be 51.5% compared to cellulose.

• Journal of Bio-Environment Control
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• v.10 no.4
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• pp.251-257
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• 2001

This experiment was conducted to investigate the effect of chitosan on the growth and yield of fall-planted potatoes. The research was carried out in fall-planted potatoes from August 2000 to Aprial 2001 at the height of 250m above sea level in Jeju Island. Soaking for 30 min. of seed potatoes in 200 times diluted solution of 3% liquid chitosan shortened days to emergence by 4 to 6 days. Stem length, number of stems and number of stolons per plant were 56.5 cm, 4.3, and 19.0, respectively, when seed potatoes were soaked for 30 min. in 200 times diluted solution of 3% liquid chitossan. Total potato yield in this treatment reached 2,963 kg per 10a and was significantly greater than in other treatments. Yield of marketable tubers (greater than 30g) per 10a for treatment of seed potatoes soaking in 200 times diluted solution of 3% liquid chitosan and for treatment of foliage spray with 200 times diluted solution of 3% liquid chitosan plus chitosna power (10 kg per 10a) miximg with soil was 2,761 kg and 2,628 kg, respectively. Contents of Mg, Fe and B were the greatest in the treatment of 30 min. soaking of seed potatoes in 200 times diluted solution of 3% liquid chitosanm. The increased contents of these elements are considered to have caused yield increase as a result of increased chlorophyll content for photosynthesis.

• Journal of Life Science
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• v.27 no.11
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• pp.1324-1330
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• 2017

Salt, or sodium chloride (NaCl), is a critical ingredient in many foods. It has roles in the flavor profiles of food products, textures of foods and preservation of foods against microbes. However, it increases risks of hypertension and is closely related to the development of cardiovascular disease. In recent years, health concerns related to sodium intake caused an increased demand for salt-reduced products in worldwide; it became necessary to develop natural salt-alternative products that are globally competitive. In a recent study, researchers succeeded in obtaining a natural salt enhancer through the hydrolysis of vegetable- and animal-matter mixtures. This study used various methods to identify and quantify peptide-containing arginine as a salt-alternative peptide (SAP) in an optimum combination. Arginine, or dipeptide-containing arginine, was analyzed as a standard substance using an NMR spectroscopy. The NMR carbon signal of the guanidine group of the standard substance was verified in a similar location (the L-arginine (Arg) was 156.8 ppm, the Arg-Alanine was 156.4 ppm and the Arg-Serine was 156.4 ppm). The results suggested that it is possible to analyze peptide-containing arginine quantitatively through the hydrolysis of vegetable- and animal-matter mixtures.

• The Journal of Natural Sciences
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• v.8 no.2
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• pp.119-127
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• 1996

The effect of sodium hydroxide treatment on some physicochemical properties of zeolite mordenite mineral was studied with chemical analyses, powder X-ray diffraction, thermal analyses, infrared analysis, measurement of carbon dioxide adsorption and gas chromatography. Mordenite mineral from tuffaceous rocks in Yeongil and Wolsung area was used as a starting material and treated with 0.1-5N NaOH aqueous solution at about $95^{\circ}C$ in the water bath for three hours.At the concentration of sodium hydroxide below 0.5N, all chemical compositions in the tuff were virtually insoluble and the mordenite structure did not change. At the concentration above 1N, the chemical compositions such as silica, alumina, etc., were dissolved. The dissolution ratio of silica was lager than that of alumina, and the ratio of silica to alumina in the tuff decreased sharply in the concentration range of 2 to 3N. Intensity of X-ray diffraction peak of mordenite (202) plane and the adsorbed amount of carbon dioxide also decreased with the increasing concentration of sodium hydroxide above 1N. These decreases corresponded to the degree of mordenite structure collapsed.The separation of gas chromatography of nitrogen, oxygen and carbon monoxide was not affected by the sodium hydroxide treatment, but elution peaks of methane and krypton tended to be broadened and their retention time was shortened. The elution peaks of both methane and krypton tended to be overlapped with those of nitrogen and oxygen.

• Journal of the Korean Chemical Society
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• v.37 no.8
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• pp.723-729
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• 1993

Cu(II) ion-responsive chemically modifed electrodes (CMEs) were constructed by incorporating 1-(2-pyridylazo)-2-naphthol (PAN) into a conventional carbon-paste mixture of graphite powder and Nujol oil. Cu(II) ion was chemically deposited on the surface of the PAN-chemically modified electrode in the absence of an applied potential by immersion of the electrode in a buffer solution (pH 3.2) containing Cu(II) ion, and then reduced at a constant potential in 0.1 M KNO$_3$. And a well-defined voltammetric peak could be obtained by scanning the potential to the positive direction. The electrode surface could be regenerated with exposure to acid solution and reused for the determination of Cu(II) ion. In 5 deposition / measurement / regeneration cycles, the response could be reproduced with 6.1${\%}$ relative standard deviation. In case of using the differential pulse voltammetry, the calibration curve for Cu(II) was linear over the range of 2.0 ${times}$ 10$^{-7}$ ∼ 1.0 ${times}$ 10$^{-6}$ M. And the detection limit was 6.0 ${times}$ 10$^{-8}$ M. Studies of the effect of diverse ions showed that Co, Ni, Zn, Pb, Mg and Ag ions added 10 times more than Cu(II) ion did not influence on the determination of Cu(II) ion, except EDTA and oxalate ions.

• Clean Technology
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• v.23 no.2
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• pp.133-139
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• 2017

Bio-based plastics containing the biomass content higher than 25 wt% have been considered as environment-friendly materials due to their effects on the reduction in the $CO_2$ emission and petroleum consumption as well as biodegradability after use. In this study, poly vinyl chloride, plant-derived plasticizers, by adding a biodegradable catalyst was observed a change in the biodegradability and physical properties. To produce the oxidative decomposition transparent bio film, which is broken down in the initial percent elongation and physical properties such as tensile strength, it was to test the safety of the product as a food packaging material. Poly vinyl chloride, primary plasticizer, secondary plasticizer, anti fogging agent, the combined stabilizer were mixed in a high speed mixer, then extruded using an extrusion molding machine, after cooling, winding, to produce a oxidative decomposition transparent bio film and the control film, with a thickness of $12{\mu}m$ through winder role. Mechanical properties tensile strength, elongation, and the maximum load elongation and biodegradation test. Transparent bio film produced by biodegradation catalyst is compared with the control film. Tensile strength and elongation of films were found to be no significant difference. Further, as a result of the biodegradation test for 45 days based on the ASTM D6954-04 method, biodegrability of film is 61.4%.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.11
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• pp.1141-1147
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• 2006

In order to applicate a newly method for powdered activated carbon(PAC) selection based on economic efficiency, PAC adsorption tests were performed for removal of MIB and dissolved organic carbon(DOC) in drinking water supplies. The removal rate of MIB increased when the PAC dose increased. The Coal-based PACs were superior for adsorption of MIB compared to wood-based PACs. PAC adsorption of DOC and $UV_{254}$ were a little different for different PACs and types of raw water, but both were lower than adsorption of MIB. Among the tested PACs, the one called P-1000 was most effective for removal of MIB, DOC and $UV_{254}$. Most of the organics in the tested samples were proven by excitation emission matrix(EEM) results to be fulvic-like materials. Especially, fulvic-like materials, humic-like materials, and soluble microbial byproduct(SMP)-like materials decreased after contact with PAC. P-1000 which had the lowest MIB cost index(MCI) was selected as the optimum PAC for the target water. PAC efficiency and treatability, particle size and distribution, and the cost associated with PAC dosing for MIB removal according to DOC concentration should all be considered before making the final selection of the best PAC for the target water.

• Clean Technology
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• v.28 no.4
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• pp.331-338
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• 2022

The objective of this study is to prepare bead-type and pellet-type Pt (1 wt%)/Kieselguhr catalysts as hydrogenation catalysts for the polycyclic aromatic hydrocarbons (PAHs) included in pyrolysis fuel oil (PFO). The optimal reaction temperature to maximize the yield of saturated cyclic hydrocarbons during the PFO-cut hydrogenation reaction in a trickle bed reactor was determined to be 250 ℃. A hydrogen/PFO-cut flow rate ratio of 1800 was found to maximize 1-ring saturated cyclic compounds. The yield of saturated cyclic compound increased as the space velocity (LHSV) of PFO-cut decreased. The difference in hydrogenation reaction performance between the pellet catalyst and the bead catalyst was negligible. However, the catalyst impregnated by Pt after molding the Kieselguhr support (AI catalyst) showed higher hydrogenation activity than the catalyst molded after Pt impregnation on the Kieselguhr powder (BI catalyst), which was a common phenomenon in both the pellet catalysts and bead catalysts. This may be due to a higher number of active sites over the AI catalyst compared to the BI catalyst. It was confirmed that the pellet catalyst prepared by the AI method had the best reaction activity of the prepared catalysts in this study. The majority of the PFO-cut hydrogenation products were cyclic hydrocarbons ranging from C₈ to C₁₅, and C₁₁ cyclic hydrocarbons had the highest distribution. It was confirmed that both a cracking reaction and hydrogenation occurred, which shifted the carbon number distribution towards light hydrocarbons.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.11
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• pp.1401-1407
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• 2008

1-Deoxynojirimycin (DNJ) is a strong $\alpha$-glucosidase inhibitor which inhibits hyperglycemia in animals. To select the Bacillus strains highly producing DNJ, 4,000 strains were isolated from soil and grain samples. By the inhibitory activity against $\alpha$-glucosidase, nine Bacillus strains were selected and then identified by 16S rDNA sequencing. B. subtilis S10 was finally selected as the best strain for the production of DNJ. Various carbon sources and nitrogen sources in culture medium were evaluated for the highest production of DNJ. As the results, the optimized concentration of carbon source and nitrogen source was 1.0% galactose and 1.6% polypeptone and the concentration of DNJ produced was 0.75 g/L. The effect of culture supernatant of B. subtilis S10 on lowering blood glucose level was investigated in streptozotocin (STZ)-induced diabetic mice model. Mice were randomly assigned to control group (saline) and three test groups such as acarbose group, silkworm powder group and B. subtilis S10 group. After eight-week oral feeding, blood glucose levels of the B. subtilis S10 and silkworm powder groups were respectively $209.1{\pm}19.6\;mg/dL$ (59.1%) and $208.6{\pm}39.8\;mg/dL$ (59.0%) lower than $510{\pm}10\;mg/dL$ of the control group. These results indicated that the culture supernatant of B. subtilis S10 was able to reduce the blood glucose level in STZ-induced diabetic mice.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.2
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• pp.181-187
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• 2004

Preparations of mesoporous materials using various templates and their applicability have been intensively investigated for many years. We studied on synthesizing mesoporous Ti02 with pores in which sensitive compounds having weak physico-chemical properties such as thermal or UV irradiation and low solubility in solvent are trapped. Prior to trapping OMC in the pores of mesoporous titania, OMC was nano-emulsified in O/W system using Lecithin. Thereafter the OMC was trapped in the pores of mesoporous titania using sol-gel method. Main focus of this work is to prepare OMC-trapped mesoporous titania and to trace the stability and solubility of nano-emulsified OMC in the pores of mesoporous titania, and compared with that of mesoporous silica. OMC-trapped mesoporous Inorganic-Organic hybrid titania showed higher factors in sun protecting and a skin penetration phenomenon was reduced.