• Membrane and Water Treatment
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• 제7권1호
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• pp.55-70
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• 2016

Microfiltration/ultrafiltration (MF/UF) Adsorptive polyamide-6 (PA-6) membranes were prepared using wet phase inversion process. The prepared PA-6 membranes are characterized by scanning electron microscopy (SEM), porosity and swelling degree. In this study, the membranes performance has examined by adsorptive removal of copper ions from aqueous solutions in a batch adsorption mode. The $PA-6/H_2O$ membranes display sponge like and highly porous structures, with porosities of 41-73%. Under the conditions examined, the adsorption experiments have showed that the $PA-6/H_2O$ membranes had a good adsorption capacity (up to 120-280 mg/g at the initial copper ion concentration ($C_0$) = 680 mg/L, pH7), fast adsorption rates and short adsorption equilibrium times (less than 1.5-2 hrs) for copper ions. The fast adsorption in this study may be attributed to the high porosities and large pore sizes of the $PA-6/H_2O$ membranes, which have facilitated the transport of copper ions to the adsorption. The results obtained from the study illustrated that the copper ions which have adsorbed on the polyamide membranes can be effectively desorbed in an Ethylene dinitrilotetra acetic acid Di sodium salt ($Na_2$ EDTA) solution from initial concentration (up to 92% desorption efficiency) and the PA-6 membranes can be reused almost without loss of the adsorption capacity for copper ions. The results obtained from the study suggested that the $PA-6/H_2O$ membranes can be effectively applied for the adsorptive removal of copper ions from aqueous solutions.

• Journal of the Korean Wood Science and Technology
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• 제51권6호
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• pp.542-554
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• 2023

This study is a continuation of our previous work, which focused on the resistance of jabon wood to termites after impregnation with wood vinegar (WV) and animal-based adhesive (kak). This paper presents the physicomechanical properties of fast-growing jabon wood impregnated with kak at two concentrations (8% and 10%) in wood vinegar or water as a solvent with and without 4% borax. The physical properties of the impregnation solution, that is, viscosity, density, pH, and solid content, were evaluated according to SNI 06-4567-1998. Some physical parameters, such as weight percent gain (WPG), density, water uptake, anti-swelling efficiency (ASE), crystallinity, and mechanical properties, i.e., modulus of elasticity (MOE), modulus of rupture (MOR), and compression strength parallel to the grain (CS), of the impregnated wood were determined. Based on these results, wood impregnated using a mixture of kak in WV presented better physical (increased WPG, density, dimensional stability, and crystallinity) and mechanical (increased MOE/MOR and compression strength) properties than wood impregnated with a water solvent or untreated wood. The wood impregnated using WV and water solvent improved the physical and mechanical properties. The density of the wood increased by 44%-58% and 32%-47%, ASE radial-tangential increased by 38%-45%; 15%-28% after 24 h of water immersion, crystallinity increased by 59%-74%; 36%, MOE increased by 46%-57%; 28%-31%, MOR increased by 29%-34%; 14%-27%, and compression strength increased by 40%-76%; 38%-72% values to untreated wood.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• 제14권1호
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• pp.240-249
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• 2001

Objective : Anal Therapy is another way of taking medicine and applies to each field of clinical treatment extensively. Sinpo-tang(SPT) has been used for the treatment of a allergic rhinitis. In this study, the auther investigated the anti anaphylactic action of Sinpo-tang by anal therapy was investigated on cutaneous allergic reaction models. Methods : Results : 1. Sinpo-tang (0,001-0.1 g/kg) dose-dependently inhibited the compound 48/80-induced ear swelling response in mice. Inhibitory effect of Sinpo-tang was significant (P < 0.05) at the doses of 0.01, 0.1 g/kg. 2. Sinpo-tang (0.001-0.1 g/kg) inhibited the cutaneous allergic reaction activated by anti-dinitrophenyl IgE in rats. Of special note, Sinpo-tang (0.1 g/kg) inhibited the cutaneous allergic reaction by $68\%$. 3. This inhibitory effect of Sinpo-tang was confirmed by observation of alcian blue/nuclear fast red stained-mast cells in the cutaneous tissue. 4. Sinpo-tang (0.01-1 g/L) dose-dependently inhibited the compound 48/80-induced histamine release from the peritoneal mast cells. Conclusions :These results indicate that anal therapy of Sinpo-tang may be beneficial in the treatment of mast cell-mediated anaphylaxis by inhibition of histamine release from mast cells in vivo and in vitro.

• Proceedings of the Korea Hospitality Industry Research Society Conference
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• 한국관광식음료학회 2005년도 학술논문발표집
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• pp.109-122
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• 2005

In accordance with changes in life style, people's desire to eat out is getting changed in their preferring factors from whether they can buy food they want to eat fast and easily to mood of the dining space, content and quality of service, hygiene condition of restaurant, quiet location and surrounding circumstance, and discount coupon and price destruction. In addition, consumers who begin to recognize the seriousness of environmental pollution prefer health-oriented food. On the other hand, excessive presence of competitors, growing personnel expense, increasing expenditure in accordance with swelling price of rent and material expenditure, increase of tax burden, decrease of income because of credit card service charge and high expected level by consumers make it difficult for restaurant's owners to manage restaurant business. Therefore, this study purposes to establish development of menu from the consumer's and the supplier's point of view and propose how to develop menu aiming at convenience, health and diversity.

• Journal of the Korean Wood Science and Technology
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• 제37권2호
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• pp.121-127
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• 2009

Acacia wood (Acacia mangium Willd.) is the most popular fast growing tree species planted in timber estate in Indonesia and is considered to be very valuable raw materials for structural composite products. The objective of the research was to evaluate the properties of OSB prepared from A. Mangium wood with or without immersing the strands to hot water at $80^{\circ}C$ for 2 hours. MDI adhesive was used in 3 levels i.e., 3%, 5%, and 7%. The moisture content of strand was 7%. The results indicated that immersing strands in hot water for 2 hours at $80^{\circ}C$ prior to manufacture OSB improved significantly the mechanical peoperties (i.e., MOR and MOE) of OSB. The higher the adhesive content resulted in the better the dimensional stabilisation (i.e., water absorption and thickness swelling) and the mechanical properties (i.e., MOR, MOE and IB) of OSB. OSB prepared from hot-water immersed strands with 5% adhesive content has met all parameters requirement on the JIS A 5908 (2003) standard.

• Journal of Biomedical Engineering Research
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• 제41권1호
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• pp.1-7
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• 2020

Polyvinyl alcohol (PVA)/gelatin hydrogels were prepared by repeating freezing/thawing three times to evaluate the influence of PVA concentration on the strength and the cell growth behavior of the PVA/gelatin hydrogels. The swelling rate of the PVA/gelatin hydrogels decreased with raising the PVA content from 6 wt% to 12 wt% due to the formation of 3-D network inside the hydrogel. No appreciable degradation of the hydrogels was detected. As the PVA content increased from 6 wt% to 12 wt%, the strength of the PVA/gelatin hydrogels increased drastically from 6.4±0.9 kPa to 46.6±9.0 kPa. The PVA/gelatin hydrogels did not show any evidence of causing cell lysis or toxicity, implying that the hydrogels are clinically safe and effective. Although the strength increased with increasing the PVA content, the PVA/gelatin hydrogels containing 8 wt% exhibited the fastest cell growth, which is highly suitable for wound dressing requiring fast healing regeneration.

• Journal of Microbiology and Biotechnology
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• 제27권10호
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• pp.1736-1743
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• 2017

Sourdough is made by fermentation of dough by lactic acid bacteria (LAB) and yeast to improve bread properties like volume, flavor, and texture. A Korean traditional sourdough was made by fermenting rice flour with rice wine (makgeolli) and used to make sponge-like bread (jeung-pyun). The aim of this study was to investigate the microbial diversity of makgeolli products and their influence on the organoleptic quality of jeung-pyun. Three commercial makgeolli were tested for jeung-pyun production, with each product exhibiting varied dough swelling rates and organoleptic qualities, and among them, J-product was ranked highest in texture and taste. Microbial analysis of the three makgeolli also showed a big difference in their population and diversity. J-product had the highest LAB and yeast counts, and the predominant species were Lactobacillus casei, Lactobacillus brevis, Leuconostoc pseudomenteroides, and Saccharomyces cerevisiae. Using J-product, sourdough was fermented at $25^{\circ}C$, $30^{\circ}C$, and $35^{\circ}C$, and the microbial growth in and textural properties of jeung-pyun were examined by instrumental and sensory tests. At high temperature ($35^{\circ}C$), the rates of dough swelling and acidification were fast due to rapid microbial growth mainly caused by LAB, resulting in a short leavening time and soft and sour jeung-pyun. Sensory tests showed consumer preference for the soft and mild-sour jeung-pyun. This study shows that LAB in makgeolli play key roles in production of jeung-pyun, influencing the textural and sensory properties. For the production of high-quality jeung-pyun, development of LAB starters with high gas productivity and low acidity and establishment of an optimal fermentation procedure for rice dough are necessary.

• Journal of the Mineralogical Society of Korea
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• 제16권4호
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• pp.295-305
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• 2003

This study aims to provide the physicochemical properties of three kinds of organo­smectites which can be diversely used in industries. Some properties of them were compared with Na­smectite. Three kinds of organo­smectites such as Hexadecyltrimethylammonium(HDTMA), Benzyldimethyltetradecylammonium(BDTDA), and Cetylpyridinium(CP) exchanged smectites were manufactured for this study. Three types of organo­smectites showed the alkaline character(pH 9), very low swelling property and viscosity, and a fast flocculation behavior because of strong hydrophobic property in contrast to hydrophilic Na­smectite. Three organo­smectites showed the strong interlayer expansion with basal spacing from $19\AA$ to $23\AA$ compared with the Na­smectite of about 12 $\AA$. Organic cations such as HDTMA, BDTDA, and CP exchanged into smectite were completely decomposed in the temperature range from $250^{\circ}C$ to $400^{\circ}C$. Generally, three organo­smectites showed the similar mineralogical, physicochemical and thermal properties. But their properties are quite different from Na­smectite. Considering economically, CP exchanged smectite would be used for the diverse utilization field in the future time.

• Polymer(Korea)
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• 제36권2호
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• pp.216-222
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• 2012

We synthesized microcapsule absorbent with crosslinked poly(styrene-$alt$-maleic anhydride) (PSMA) as a core and PSMA as a shell by a precipitation polymerization method for the delayed absorption of excess water in cement mortar. cPSMA-PSMAs with core-shell structure were synthesized with ratios of 1/1, 1/2 and 1/3 as core monomer mass to shell monomer mass to control shell thickness. We observed the hydrolysis of PSMA in cement-saturated aqueous solution by a FTIR spectrometer. We observed good core-shell structure microcapsules for 1/2(cPSMA #3), but observed incomplete core-shell structure for 1/1(cPSMA #2) and 1/3(cPSMA #4) of core/shell monomer ratios. The swelling ratio of cPSMA #3 in cement-saturated aqueous solution was increased until 20 min. After that it was decreased until 2 hrs swelling time, and they started to increase again. The viscosities of cement paste with cPSMA #3 microcapsules were very slowly increased until 1 hr and increased fast after 1.5 hrs. Cement mortar with 0.5 wt% cPSMA #1 having only core part showed about 5% increase in compressive strength compared to that of plain cement mortar. cPSMA #3 added cement mortar showed the highest compressive strength with 7% increase.

• Journal of the Korean Wood Science and Technology
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• 제35권2호
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• pp.51-60
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• 2007

In this study, the possibility of using pyrolysis oil as wood adhesives was explored. Especially, adhesives were formulated by reacting pyrolysis oil and formaldehyde and also partially replacing phenol with pyrolysis oil in phenol-formaldehyde (PF) adhesive and soy hydrolizate/PF adhesive formulation. The pine wood was fast pyrolyized and the oils were obtained from a series of condensers in the pyrolysis system. The oils from each condenser were first reacted with formaldehyde to explore potential use of the oil itself as adhesive. The lap-shear bond strength test results indicated that the oil itself could be polymerized and form bonds between wood adherends. The oils from each condenser were then mixed together and used as partial replacement of phenol (25, 33, and 50% by weight) in phenol-formaldehyde adhesive. The bond strength of the oil containing PF adhesives was decreased as percent phenol replacement level increased. However, no significant difference was found between 25 and 33% of phenol replacement level. The oil-contained PF resins at 25, 33, and 50% phenol replacement level with different NaOH/Phenol (Pyrolysis oil) molar ratio were further formulated with soy hydrolizate to make soy hydrolizate/pyrolysis oil-phenol formaldehyde adhesive at 6:4 weight (wt) ratio and used for fiberboard manufacturing. Surface internal bond strength (IB) of the boards bonded with 33% replacement at 0.3 NaOH/Phenol (Pyrolysis oil) molar ratio performed better than other replacement levels and molar ratios. Thickness swelling after 24 hr cold water soaking and after 2 hr in boiling water was increased as % replacement of pyrolysis oil increased.