• KSBB Journal
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• v.10 no.4
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• pp.468-474
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• 1995

The disposable glucose bio-sensor using composite of CTA and PCL membrane was developed for measurement of glucose. The most effective membrane was composed of CTA/PCL(80/20, w/w) and glutaraldehyde one-step immobilization method ($10{\mu}m$ thickness) for glucose sensor gave the best result among various methods, considering oxygen permeability and electronic sensitivity. A scanning electron micrograph of the cross-section of a typical asymmetric CTA/PCL composite membrane showed that the membrane fused with a dense layer covered with a GOD-glutaraldehyde. Glucose oxidase immoblilized on the membrane showed the linearity between difference of absolute amperometric values and glucose concentrations within 7mM when the GOD immobilized electrode was used. About 35% of activity was remained after 8 days when the tyrosinase was immobilized on CTA/PCL (80/20) membrane.

• Journal of the Korean Chemical Society
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• v.51 no.2
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• pp.178-185
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• 2007

Intermediate pentasil borosilicate zeolite-like materials have been crystallized by a novel method named steam-assisted conversion, which involves vapor-phase transport of water. Indeed, amorphous powders obtained by drying Na2O.SiO2.B2O3.TBA2O gels of various compositions using different boron sources are transformed into crystalline borosilicate zeolite belonging to pentasil family structure by contact with vapors of water under hydrothermal conditions. Using a variant of this method, a new material which has an intermediate structure of MFI/MEL in the ratio 90:10 was crystallized. The results show that steam and sufficiently high pH in the reacting hydrous solid are necessary for the crystallization to proceed. Characterization of the products shows some specific structural aspects which may have its unique catalytic properties. X-ray diffraction patterns of these microporous crystalline borosilicates are subjected to investigation, then, it is shown that the product structure has good crystallinity and is interpreted in terms of regular stacking of pentasil layers correlated by inversion centers (MFI structure) but interrupted by faults consisting of mirror-related layers (MEL structure). The products are also characterized by nitrogen adsorption at 77 K that shows higher microporous volume (0.160 cc/g) than that of pure MFI phase (0.119 cc/g). The obtained materials revealed high surface area (~600 m2/g). The infrared spectrum reveals the presence of an absorption band at 900.75 cm-1 indicating the incorporation of boron in tetrahedral sites in the silicate matrix of the crystalline phase.

• Journal of Conservation Science
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• v.21
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• pp.73-88
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• 2007

In this paper, the interaction between five biocides(commercial) and two ethylsilicate consolidants for stone monuments, reacted in different sequence, has been studied. Through the structures, weight and gelation time of mixture of biocides and consolidants have been evaluated the reactivity of biocide alone, the reactivity of consolidants and biocides, the reactivity of consolidants and dried biocide, and the reactivity of ethylsilicate gel and biocides. The tested biocides show quite different properties from those of consolidants; after evaporation, some biocides are remained white salt crystals, another need the long time for evaporation and one biocide shows pale brown color. The results have shown an interaction of the tested products each other in some application sequences of the products. When the application of liquid state biocides with consolidants, it was noted that some biocide seem to interfere with the formation of gel due to reaction of consolidants and water and salts in biocides. In the reaction of ethylsilicate with dried biocides have shown a heterogenous gel(transparent layer with ethylsilicate alone and white layer which is mixed biocide and ethylsilicate) and many cracks in product due to the different shrinkage, thus the products don't play a role as consolidants. There is no change in structures and color in reaction of the gas state biocide and ethylsilicate gel.

• Journal of the Korean Association of Geographic Information Studies
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• v.2 no.1
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• pp.12-31
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• 1999

Topex/Poseidon satellite altimetric data are used to estimate characteristics on the oceanic and atmospheric correction factors, and the mean sea level and its variations in the Yellow Sea, the East China Sea and the East Sea from September 1992 through August 1994(70cycles). For the atmospheric correction factors, the variations of dry troposphere, humid troposphere, ionosphere and inverted barometer were very small as a few centimeters, but the variations of electromagnetic bias were higher than other factors. For the oceanic correction factors, the variations of ocean tide(35cm in track 127 and 60cm in track 214) showed high ranges compared to elastic tide(5cm in track 127 and 1cm in track 214) and loading tide(1.8cm in track 127 and 1cm in track 214). It should be understood that the variations of ocean free surface is mainly under the influence of, firstly, ocean tide and, secondly, electromagnetic bias. Mean sea level in the Yellow Sea are higher than in the rest of Seas. Then its range generally comprised between -60cm and 210cm with mean value of about 100cm. Also its variations showed high values in the Yellow Sea and East China Sea, especially 5.689cm in Youngampo. This result is mainly due to the effects of local topography and tidal current.

• Journal of the Korean Geosynthetics Society
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• v.18 no.1
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• pp.25-37
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• 2019

This study confirms reinforcing effect of geosynthetics in the use of soil at higher water contents as a compaction material on compaction tests, field compaction tests, and numerical analysis. To verify a confined effect, a large mold(area ratio of rammer / mold = 0.19) larger than D compaction mold(area ratio of rammer / mold = 0.33) was performed for compaction. It showed that in the D compaction test, dry density were 0.5~0.6% increases and in the compaction test using the large mold, it were 2.4~3.7% increases at high water contents. It shows that when the area of compacted area is large enough, a confined effect could be arising from the reinforcement of geosynthetics even at high water contents. As a result of analyzing of compaction effects according to 'depth(z/B) from compacted surface' in the field, when not reinforced, the compaction state deteriorated due to the over-compaction and the compaction did not work well. However, when reinforcement of geosynthetics, restraint effect by geosynthetics occurs, it is confirmed that the compaction energy is effectively transferred to the compaction layer and the dry density is increased. Also, through the conceptual model of the behavior of geosynthetic and soil layer, the mechanism in the ground due to reinforcement of geosynthetics is presented and it is verified through finite element analysis.

• Membrane Journal
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• v.17 no.3
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• pp.174-183
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• 2007

The manufacturing process of metal membrane made of only metal mesh and both metal mesh and powder with using rolling process have been studied. In the rolling of metal mesh, selected metal meshes were rolled with the reduction ratio of 10%, 20%, and 30%, respectively. Such rolling process resulted in the decrease of mesh pore size through reduction the cross sectional area of mesh and changing the diameter of mesh wires. Also, it enhanced the filtration ratio of rolled mesh which is almost same as the filtration ratio of upper grade unrolled mesh and the reliability of membrane by making pore size distribution become more uniform. In fabricating metal powder layer onto metal mesh, using PVA(polyvinyl alcohol) as a binder of powder, drying the metal powder layer at $100^{\circ}C$ for 1 hr, and sintering it at $1,000^{\circ}C$ for 3 hr in vacuum were to be optimum conditions for obtaining good quality of metal powder layer on metal mesh with high pore density but no crack. With additional rolling of metal powder layer on metal mesh with 30% reduction before sintering, metal membrane which filtration ratio is about $0.7{\mu}m$ has been successfully manufactured.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.38 no.1
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• pp.75-82
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• 2012

Natural moisturizing factors (NMFs) are hydrophilic and water-soluble components in stratum corneum of the skin. NMFs absorb water from outer environment and enhance the water-holding capacity of stratum corneum and thereby, prevent the dryness and increase flexibility and plasticity of skin. NMFs are mainly composed of amino acids and their metabolites that are produced from the degradation of filaggrin. Here we established a simultaneous quantification method for 22 amino acids in tape-stripped stratum corneum samples using UPLC-PDA. With this method, we analyzed amino acid contents from tape-stripped stratum corneum samples of forearm and forehead regions from 15 healthy volunteers. Amino acid contents of inner (or upper) region were higher than outer (or lower) region of stratum corneum. Amino acid contents of stratum corneum of forearm were higher by 1.5 fold than forehead region. Of note, total amino acid contents were significantly and inversely correlated with trans-epidermal water loss (TEWL), an index for skin barrier function. Especially, Ser, Glu, Gly, Ala and Thr were determined to positively affect skin mositurizing activities. In conclusion, we could demonstrate that amino acid contents of stratum corneum are closely linked with skin barrier and moisturizing function, providing an important and fundamental methodology for the study of amino acids in skin physiology.

• Food Science of Animal Resources
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• v.23 no.4
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• pp.350-355
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• 2003

Raw skim milk and colloidal calcium phosphate-free skim milk were treated with microbial transglutaminase (TGase), ultracentrifuged at varying rates and were observed to contain textural properties using a scanning electron microscope (SEM). Skim milk showed irregular signs of conformation at lower centrifugal rate, and associated regular (10,000 ${\times}$g) and thin with broad holes (20,000 ${\times}$g). The associated texture became thick and irregular (40,000 ${\times}$g), and fine particles were regularly associated (100,000 ${\times}$g). When skim milk was incubated for 1 hr with TGase, casein micelles aggregated and broadened as centrifugation rate increased. When skim milk was incubated for 8 hrs with TGase, casein micelles associated to large widened aggregates, and were associated regularly which then became irregular (100,000 ${\times}$g). When colloidal calcium phosphate-free skim milk incubated for 1 hr with TGase showed no sediment, the milk incubated for 8 hrs with TGase associated together, yielding broadened and regular layers as the centrifugation rate increased. It is assumed that such phenomena could be caused by protein crosslinking reaction with TGase and conformational change of casein molecules, as well as dependencies on reaction time, temperature and ultracentrifugation rate.

• Journal of Life Science
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• v.14 no.2
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• pp.286-290
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• 2004

The antioxidant activities of the various fractions extracted from mustard leaf (Brassica juncea) and mustard leaf kimchi were determined by the radical scavenging effect on 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical. The fractions from dried mustard leaf, and fermented mustard leaf kimchi for 0 day and fermented mustard leaf kimchi for 5 days at 15$^{\circ}C$ were screened for the scavenging effects by using DPPH assay. The fractions prepared by the systematic extraction procedure with the solvents such as hexane, C $H_2$Cl$_2$, EtOAc, BuOH and $H_2O$ were used for the determination of free radical scavenging effects. The antioxidant activity of EtOAc and n-BuOH soluble fraction from mustard leaf and mustard leaf kimchi for 0 day had stronger than the others. During fermentation at 15$^{\circ}C$ for 5 days, the antioxidant activity was changed. C $H_2$Cl$_2$ and EtOAc soluble fraction showed more potent radical scavenger effects than the others. The difference or results were to the various supplements and fermentation process.

• Journal of the Korean Geographical Society
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• v.44 no.4
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• pp.463-480
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• 2009

The weathering properties and provenance of loess-paleosol sequence deposited on gravel layer of river terrace in Bongdong-eup, Wangju-gun, Jeonbuk Province are examined using soil analysis, magnetic susceptibility measurement, grain size and element analysis. The Bongdong section consists of, from top to bottom, Layer 1(paleosol), Layer 2(loess), Layer 3(paleosol) and the gravel layer of river terrace. The magnetic susceptibility values show the systematic variations in the sequence and the results of grain size analysis reveal that the sequence was deposited by not fluvial or slope process, but eolian process, and that contains finer materials than the Daecheon loess and Chinese Loess Plateau. Among the results of soil analysis, organic contents indicate systematic variations similar to the magnetic susceptibility. The wet soil colors further reflect the characteristics of the sequence rather than the dry soil colors. Based on the analytical results of major and rare earth elements, the eolian materials contained in the sequence were deposited by the materials originated from the areas where the Chinese Loess Plateau has been originated or the reworked materials from the Chinese Loess Plateau, and after the depositions, the materials experienced the intensive chemical weathering under the humid-warm climatic conditions in the Korean Peninsula.