• Clean Technology
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• v.29 no.2
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• pp.109-117
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• 2023

The purpose of this study is to develop a method for separating antioxidants and sugars from grape skin extract. The extract was first mixed with a variety of organic solvents to investigate whether the separation was feasible. When employing acetone, ethanol, dimethylsulfoxide, or dimethylformamide, the organic solvent-extract combination formed a single phase. However, when benzene, ethyl acetate, or n-hexane was added to the extract, the mixture separated into an organic and an aqueous phase and the pigments remained in the aqueous phase. On the other hand, when polyethylene glycol-2,000 (PEG-2000) and sodium citrate were added to the extract, the mixture was separated into three layers, with the majority of the flavonoids migrating to the top layer and 53% of the extract's glucose migrating to the bottom layer. The top layer had significant antioxidant activity, whereas the bottom layer showed no antioxidant activity. The glucose recovery in the bottom layer increased as the molecular weight of PEG increased and the highest recovery (67%) was observed when PEG-8,000 was added. The highest flavonoid separation was observed with PEG-2,000, followed by PEG-8,000 and PEG-400. The flavonoid separation when PEG-2,000 was added resulted in a flavonoid recovery of 48% and 0.2% from the top and bottom layers, respectively. Examining the effect of the separated solution using the agar disc diffusion method on yeast cell growth confirmed that the addition of the extract, the top, and the bottom layer did not inhibit cell growth.

• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.1
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• pp.61-66
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• 1985

Cooked rice was prepared by the conventional cooking method being used among Korean families. The bottom layer (very slightly roasted and charred) and upper layer of the cooked rice in a cooking vessel were collected separately in order to determine the chemical changes and volatile carbonyl formation occurring in rice during the cooking process. Amino acids, especially free amino acid contents were reduced with the decrease of reducing sugar in rice after cooking. A little change was shown in the fatty acid composition of lipid fractions, however, decreased iodine values and increased fatty acid values were observed after cooking process. Volatile carbonyl compounds from cooked rice were isolated and 8 carbonyls of them were identified. A significant difference of relative composition of the identified carbonyls was found between the upper layer and bottom layer of cooked rice. Generally, the cooked rice obtained from the bottom layer had shown a little more changes in chemical composition and a stronger browning flavour than those of the upper layer of cooked rice.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.3
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• pp.185-191
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• 1990

A study on the characteristics of phosphorus sedimentation in Nakdong Estuary Barrage was conducted in June and July, 1989. Cylindric type sediment trap was designed for collecting of downward material. Downward flux and settling velocity of downward material were $296g/m^2/d$, 1.25m/hr in mid-layer and $955g/m^2/d$, 3.31m/hr in bottom-layer, respectively Downward flux and settling velocity of phosphorus were $0.64g/m^2/d$, 0.85m/hr in mid-layer and $1.97g/m^2/d$, 1.89m/hr in bottom-layer, respectively. Fractional composition of organic phophorus in downward material was $51.9\%$ in mid-layer water and $48.3\%$ in bottom-layer water. According to the result of this study, sedimentation of phosphorus plays an important role as a sinking effect in Nakdong Estuary Barrage.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.52-54
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• 2008

The authors investigated the InGaN/GaN multi-quantum well blue light emitting diodes with the implements of the photonic crystals fabricated at the top surface of p-GaN layer or the bottom interface of n-GaN layer. The top photonic crystals result in the lattice-dependent photoluminescence spectra for the blue light emitting diodes, which have a wavelength of 450nm. However, the bottom photonic crystal shows a big shift of the photoluminescence peak from 444 nm to 504 nm and played as a role of quality enhancement for the crystal growth of GaN thin film. The micro-Raman spectroscopy shows the improved epitaxial quality of GaN thin film.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.8
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• pp.981-994
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• 2014

Density currents formed by buoyancy discharges from rivers are numerically studied using non-dimensional two layer model including Coriolis acceleration, bottom stress, interfacial friction. Some typical numbers such as Froude number, densimetric Froude number and Kelvin number are obtained and some characteristic scales are defined as a result of non-dimensionalization of the governing equations. Besides the Coriolis effect, the configurations of bottom topography, bottom friction coefficient and interfacial friction are found to significantly affect the propagation of the warm water plume. Frontal position can fastly propagate in the case of large density difference between the two layers and small interfacial friction. Left side boundary current is easily formed under the small interfacial friction. With large Kelvin number, both right and left side boundary currents are formed. Wave-like disturbances and eddies are easily formed under the high Froude number.

• Journal of the Korean Society of Visualization
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• v.2 no.2
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• pp.38-44
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• 2004

Theoretical and numerical studies are given to the sink flows within a rotating circular tank driven by the fluid withdrawal from a bottom circular hole. It was found that, when the upper free surface was set with no-slip boundary conditions, the Ekman boundary-layer develops not only above the bottom surface but under the top surface. The sink fluid is coming from the two Ekman layers, and the mass transfer from the bulk, inviscid region is dependent on the rotational speed. It is also remarkable to see that all the fluid gathered along the axis flows in a form of rapidly rotating fluid column haying almost the same diameter as the bottom hole.

• Journal of the Korean Institute of Navigation
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• v.21 no.4
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• pp.39-47
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• 1997

We researched the mechanism on th flucturain of Bottom Cold Water in the western channel of Korea Strait, using 13 years(1981~1933) oceanographic data of FRDA. The bottom cold water in the western channel appears more often in summer and fall than in winter and spring, and its year-to-year variation of temperature is very large. Such variation seems to be closely related with the variations of cold waters in the subsurface layer of the southwestern East Sea. According to the longitudinal temperature distribution along the korean southeastern coast, a density difference occurs all the time at the still deepth between the western channel and the southwestern East Sea. Thus, it is inferred that the cold waters would intrude into the western channle form the subsurface layer in the southwestern East Sea as a density-driven current, and it intensity depends upon the density difference.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.614-615
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• 2016

I studied electrical coupling of monolithic 3D inverter(M3D-INV) consisting of Junctionless FET(JLFET). If the thickness of Inter Layer Dielectric (ILD) between top JLFET and bottom JLFET is less than 50nm, current-voltage characteristic of top JLFET is rapidly changed by the gate voltage of bottom JLFET. Therefore, you have to consider about the electrical interaction according to the thickness between top JLFET and bottom JLFET in M3D-INV.

• 한국해양학회지
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• v.15 no.1
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• pp.58-61
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• 1980

Water movements at nine different layers were observed from July 31 to August 2, 1976 at station H, which has water depth 42 meters and 3km far from the coast of Wolsong, and dispersion coefficients were computed from these current data, then relative magnitudes of dispersion coefficients were calculated at each layers. Relative magnitudes of dispersion coefficients based on the surface value are 62% at 5m layer, 24% at 10m layer, 20% at 15m and 20m layers, 17% at 25m layer, 24% at 30m layer, 28% at 35m layer and 15% at bottom layer, respectively.

• Journal of Electrical Engineering and Technology
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• v.6 no.5
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• pp.688-692
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• 2011

Carbon nanotubes (CNTs) are vertically grown inside high-aspect-ratio vertical pores of anodized aluminum oxide. A CNT catalyst layer is introduced by atomic layer deposition to the bottom of the pores, after which the CNTs are successfully grown from the layer using chemical vapor deposition. The CNTs formed a complete vertical conductive path. The conductivity of the CNT-vertical path is also measured and discussed. The present atomic layer deposition-incorporated catalyst deposition is predicted to enable the integration of CNTs with various challenging configurations, including high-aspect-ratio vertical channels or vertical interconnects.