• Development and Reproduction
• /
• v.4 no.2
• /
• pp.161-173
• /
• 2000

The aim of this study was to assess the effect of the frequency of the L$N_2$ infusion on the ultrastructure, metabolism and development of the embryo after freezing and thawing by computerized cell freezer. Two-cell embryos of ICR mouse were randomly allocated into fresh (control), high-frequency freezing (group 1) and low-frequency freezing (group 2). For fresh and frozen-thawed intact 2-cell embryos, total ceil number in the blastocyst was counted by fluorescent microscope after Hoechst 33258 staining. Relative amount of $H_2O$$_2$ was measured by DCHFDA. Intracellular location and membrane potential of the mitochondria were evaluated by staining with rhodamine 123 and JC-1. The structure of actin filament was also evaluated by confocal microscope. DNA fragmentation was assessed by TUNEL method after development into blastocyst. The survival rate of intact embryo was higher in group 1 than group 2 (50.7％ vs. 34.6％ respectively, p<0.05). The blastocyst developmental rate was significantly low in group 2 (86.7％, 76.7％ vs. 44.0％ for control, group 1 and group 2 respectively, p<0.05). Total cell number in the blastocyst was also significantly lower in group 2 than control (79.5$\pm$12.9, 71.6$\pm$8.0, and 62.5$\pm$4.7 for control, group 1 and group 2 respectively, p<0.05). The relative amount of $H_2O$$_2$ was higher in group 2 than other groups (15.3$\pm$3.0, 16.6$\pm$1.6 vs. 23.4$\pm$1.8, p<0.05). After JC-1 staining, relative intensity of mitochondria with high membrane potential was significantly lower in group 2 than control and group 1 (17.2$\pm$3.8, 17.4$\pm$1.3 vs. 13.2$\pm$2.0, p<0.05). In group 2, partial deletion and aggregation of the actin filament was found. DNA fragmentation rate was also hieher for group 2 versus other groups (30.8％, 36.0％ vs. 65.6％, p<0.05). The frequency of the L$N_2$ infusion is an important factor for the development of frozen-thawed mouse embryo. High-frequency infusion may prevent damages of cytoskeleton and mitochondria in the embryo probably by preventing the temperature fluctuation during dehydration phase. We speculate that the application of high-frequency infusion method in human embryo may be promising.

• Journal of Korean Society of Disaster and Security
• /
• v.9 no.2
• /
• pp.63-75
• /
• 2016

For safe water supply, residual chlorine has to be maintained in tap-water above a certain level from drinking water treatment plants to the final tap-water end-point. However, according to the current literature, approximately 30-60% of residual chlorine is being lost during the whole water supply pathways. The losses of residual chlorine may have been attributed to the current tendency for water supply managers to reduce chlorine dosage in drinking water treatment plants, aqueous phase decomposition of residual chlorine in supply pipes, accelerated chlorine decomposition at a high temperature during summer, leakage or losses of residual chlorine from old water supply pipes, and disappearances of residual chlorine in water storage tanks. Because of these, it is difficult to rule out the possibility that residual chlorine concentrations become lower than a regulatory level. In addition, it is concerned that the regulatory satisfaction of residual chlorine in water storage tanks can not always be guaranteed by using the current design method in which only storage capacity and/or hydraulic retention time are simply used as design factors, without considering other physico-chemical processes involved in chlorine disappearances in water storage tank. To circumvent the limitations of the current design method, mathematical models for aqueous chlorine decomposition, sorption of chlorine into wall surface, and mass-transfer into air-phase via evaporation were selected from literature, and residual chlorine reduction behavior in water storage tanks was numerically simulated. The model simulation revealed that the major factors influencing residual chlorine disappearances in water storage tanks are the water quality (organic pollutant concentration) of tap-water entering into a storage tank, the hydraulic dispersion developed by inflow of tap-water into a water storage tank, and sorption capacity onto the wall of a water storage tank. The findings from his work provide useful information in developing novel design and technology for minimizing residual chlorine disappearances in water storage tanks.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.48 no.6
• /
• pp.429-433
• /
• 2003

trans-Resveratrol(3,5,4'-trihydroxystilbene) is phenolic compound present in grapes, wines, and peanuts, has been reported to have health benefits including anticarcinogenic effects, protection against cardiovascular diseases and reduced cancer risk. A simple method for the quantitative extraction of trans-resveratrol from peanut has been developed. Optimal conditions for extraction were investigated. Type of solvent, time, and temperature assayed influenced trans-resveratrol yield. Adequate extraction condition was decided to ethanol/water (80:20v/v) maintained at $25^{\circ}C$ for 45 min. After extraction, the protocol consists of sample preparation using a $\textrm{C}_{18}$ solid-phase extraction (SPE) cartridge after concentrate with rotary evaporator and quantified by reversed phase HPLC using a $\textrm{C}_{18}$ column at 308 nm. Analytical methods for measuring trans-resveratrol in peanut were adapted to isolate, identify, and quantify trans-resveratrol in 11 peanut varieties by HPLC (high-performance liquid chromatography) with UV detector, The 11 peanut varieties content ranged from 0.018 to 1.125 $\mu\textrm{g}/\textrm{g}$ with an average of 0.289 $\mu\textrm{g}/\textrm{g}$. The contents were higher in the seeds with than without testa, regardless of varieties. The trans-resveratrol content was Higher in 110, 130 days after sowing than that of other period.

• KSBB Journal
• /
• v.23 no.1
• /
• pp.90-95
• /
• 2008

In this study, a combined process of sequential anaerobic-aerobic digestion (SAAD), fluidized-bed bioreactor (FBBR), and ultrafiltration (UF) for the treatment of small scale food waste leachate was developed and evaluated. The SAAD process was tested for performance and stability by subjecting leachate from food waste to a two-phase anaerobic digestion. The main process used FBBR composed of aerators for oxygen supply and fluidization, three 5 ton reaction chambers containing an aerobic mesophilic microorganism immobilized in PE (polyethylene), and a sedimentation chamber. The HRTs (hydraulic retention time) of the combined SAAD-FBBR-UF process were 30, 7, and 1 day, and the operation temperature was set to the optimal one for microbial growth. The pilot process maintained its performance even when the CODcr of input leachate fluctuated largely. During the operation, average CODcr, TKN, TP, and salt of the effluent were 1,207mg/L, 100mg/L, 50 mg/L, and 0.01 %, which corresponded to the removal efficiencies of 99.4%, 98.6%, 89.6%, and 98.5%, respectively. These results show that the developed process is able to manage high concentration leachate from food waste and remove CODcr, TKN, TP, and salt effectively.

• Journal of the Mineralogical Society of Korea
• /
• v.20 no.1 s.51
• /
• pp.7-19
• /
• 2007

Four types of fluid inclusions are trapped within tourmaline from Daeyou pegmatite, Jangsu-Gun, Jeonllabukdo. They range $5{\sim}100\;{\mu}m$ in size and are grouped into I, II, III, and IV based on the phase behavior at the room temperature: (1) Type I inclusions are liquid-rich and NaCl equivalent salinity ranged $0{\sim}12\;wt%$, and the homogenization temperatures (Th) ranged $181{\sim}230^{\circ}C$ with eutectic temperatures (Te) $-54{\sim}-22^{\circ}C$. (2) Type II inclusions are vapor-rich and salinity ranged $3{\sim}8\;wt%$ NaCl, and Th ranged $177{\sim}304^{\circ}C$ also showing Te $-54{\sim}-29^{\circ}C$. (3) Type III inclusions contain a halite daughter mineral with $31{\sim}40\;wt%$ NaCl, Th $230{\sim}328^{\circ}C$. More than 90% of Type III homogenize by halite dissolution and are spatially associated with silicate melt inclusions. (4) Type IV inclusions are $CO_{2}$-bearing containing various daughter minerals such as sylvite and/or halite. The density of $CO_{2}$ system within the Type IV is $0.80{\sim}0.75\;g/cm^{3}$, Th $190{\sim}317^{\circ}C$, and salinity $2{\sim}35\;wt%$ NaCl. Type III fluid inclusions, considered as the earliest fluid, formed from the fluid exsolved from the crystallizing pegmatite. It is suggested that Type II fluid in the central part of tourmaline were exsolved earlier than Type I fluids in the margin indicating salinity fluctuation during the growth of tourmaline. It implies the fluctuation of the pressure since the salinity of fluid exsolved from the crystallizing melt is governed by the pressure. The last fluid was Type IV, which may be derived from the nearby limestone and metasedimentary rocks. It is suggested that Daeyou pegmatite containing muscovite without miarolitic cavities was formed by the partial melting resulted from the regional metamorphism. Subsequently, the exsolving fluids from the crystallizing melt were trapped in tourmaline at high pressure condition. The exsolved fluids contain various components such as $CaCl_{2}\;and\;MgCl_{2}$ as well as NaCl and KCl. The exsolution began at least at $2.7{\sim}5.3\;kbar\;and\;230{\sim}328^{\circ}C$ with the pressure fluctuation.

• Journal of the Korean Magnetics Society
• /
• v.22 no.3
• /
• pp.85-90
• /
• 2012

Oxidation of the $Nd_2Fe_{14}B$ compound crystal and its effect on the coercivity of the fine $Nd_2Fe_{14}B$ crystal particles were investigated. Oxidation kinetics of the $Nd_2Fe_{14}B$ compound crystal was investigated using an excessively grown $Nd_2Fe_{14}B$ grains in the $Nd_{15}Fe_{77}B_8$ alloy ingot. Oxidation of the $Nd_2Fe_{14}B$ compound crystal occurred by dissociation of the phase into multi-phase mixture of ${\alpha}$-Fe, $Fe_3B$, and Nd oxides. Oxidation rate of the $Nd_2Fe_{14}B$ compound crystal showed no dependence on the crystallographic direction. The oxidation reaction was modeled according to simple linear relationship. Activation energy for the oxidation of $Nd_2Fe_{14}B$ compound crystal was calculated to be approximately 26.8 kJ/mol. Fine $Nd_2Fe_{14}B$ crystal particles in near single domain size was prepared by ball milling of the HDDR-treated $Nd_{15}Fe_{77}B_8$ alloy, and these particles were used for investigating the effect of oxidation on the coercvity. The near single domain size $Nd_2Fe_{14}B$ crystal particles (${\fallingdotseq}0.3\;{\mu}m$) had high coercivity over 9 kOe. However, the coercivity was radically reduced as the temperature increased in air (<2 kOe at $200^{\circ}C$). This radical coercivity reduction was attributed to the soft magnetic phases, ${\alpha}$-Fe and $Fe_3B$, which were formed on the surface of the fine particles due to the oxidation.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.29 no.6
• /
• pp.327-340
• /
• 2017

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2016. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of flow, heat and mass transfer, the reduction of pollutant exhaust gas, cooling and heating, the renewable energy system and the flow around buildings. CFD schemes were used more for all research areas. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results of the long-term performance variation of the plate-type enthalpy exchange element made of paper, design optimization of an extruded-type cooling structure for reducing the weight of LED street lights, and hot plate welding of thermoplastic elastomer packing. In the area of pool boiling and condensing, the heat transfer characteristics of a finned-tube heat exchanger in a PCM (phase change material) thermal energy storage system, influence of flow boiling heat transfer on fouling phenomenon in nanofluids, and PCM at the simultaneous charging and discharging condition were studied. In the area of industrial heat exchangers, one-dimensional flow network model and porous-media model, and R245fa in a plate-shell heat exchanger were studied. (3) Various studies were published in the categories of refrigeration cycle, alternative refrigeration/energy system, system control. In the refrigeration cycle category, subjects include mobile cold storage heat exchanger, compressor reliability, indirect refrigeration system with $CO_2$ as secondary fluid, heat pump for fuel-cell vehicle, heat recovery from hybrid drier and heat exchangers with two-port and flat tubes. In the alternative refrigeration/energy system category, subjects include membrane module for dehumidification refrigeration, desiccant-assisted low-temperature drying, regenerative evaporative cooler and ejector-assisted multi-stage evaporation. In the system control category, subjects include multi-refrigeration system control, emergency cooling of data center and variable-speed compressor control. (4) In building mechanical system research fields, fifteenth studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, renewable energies, etc. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which could be help for improving the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the analyses of indoor thermal environments controlled by portable cooler, the effects of outdoor wind pressure in airflow at high-rise buildings, window air tightness related to the filling piece shapes, stack effect in core type's office building and the development of a movable drawer-type light shelf with adjustable depth of the reflector. The subjects of building energy were worked on the energy consumption analysis in office building, the prediction of exit air temperature of horizontal geothermal heat exchanger, LS-SVM based modeling of hot water supply load for district heating system, the energy saving effect of ERV system using night purge control method and the effect of strengthened insulation level to the building heating and cooling load.

• Economic and Environmental Geology
• /
• v.28 no.2
• /
• pp.109-121
• /
• 1995

The hydrothermal vein type deposits which comprise the Kasihan, Jompong and Gempol mineralized areas are primarily copper and zinc deposits, but they are also associated with lead and/or gold mineralization. The deposits occur within the Tertiary sedimentary and volcanic rocks in the Southern Mountain zone of the eastern Java island, Indonesia. Mineralization can be separated into two or three distinct stages (pre-and/or post- ore mineralization stages and main ore mineralization stage) which took place mainly along pre-existing fault breccia zones. The main phase of mineralization (the main ore stage) can be usually classified into three substages (early, middle and late) according to ore mineral assemblages, paragenesis, textures and their chemical compositions. Ore mineralogy and paragenesis of the three areas in the district are different from each other. Pyrite, pyrrhotite (/arsenopyrite), iron-rich (up to 20.5 mole % FeS) sphalerite and (Cu-)Pb-Bi sulfosalts are characteristic of the deposits in the Kasihan (/Jompong) area. On the other hand, pyrite + hematite + magnetite + iron-poor (2.7 to 3.6 mole % FeS) sphalerite assemblage is restricted to the Gempol area. Fluid inclusion data suggest that fluids of the main ore stage evolved from initial high temperatures (near $350^{\circ}C$) to later lower temperatures (near $200^{\circ}C$) with salinities ranging from 0.8 to 10.1 equiv. wt. percent NaCl. Each area represents a separate hydrothermal system: the mineralization at Kasihan and Jompong were largely due to early fluid boiling coupled with later cooling and dilution, whereas the mineralization at Gempol was mainly resulted from cooling and dilution by an influx of cooler meteoric waters. Fluid inclusion evidence of boiling indicates that pressures of ${\geq}95$ to 255 bars (${\geq}95$ bars for the Gempol area: $\approx$ 120 to 170 bars for the Jompong area: $\approx$ 140 to 255 bars for the Kasihan area) during portions of main ore stage mineralization. Equilibrium thermodynamic interpretation indicates that the evolution trends of the temperature versus fS2 variation of ore stage fluids in the Pacitan district follow two fashions: ore fluids at Kasihan and Jompong changed from the pyrite-pyrrhotite sulfidation stage towards pyritehematite- magnetite state, whereas those at Gempol evolved nearly along pyrite-hematite-magnetite reaction curve with decreasing temperature. The sulfur isotope compositions of sulfide minerals are consistent with an igneous source of sulfur with a ${\delta}^{34}S_{{\Sigma}s}$ value of about 3.3 per mil. The oxygen and hydrogen isotopic compositions of the fluids in each area indicate a progressive shift from the dominance of highly exchanged meteoric water at early hydrothermal systems towards an un- or less-exchanged meteoric water at later hydrothermal systems.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.8 no.4
• /
• pp.229-241
• /
• 2006

Global air temperature has risen by $0.6^{\circ}C$ over the last one hundred years due to increased atmospheric greenhouse gases. Moreover, this global warming trend is projected to continue in the future. This study was carried out to evaluate spatial variations in rice production areas by simulating rice-growth and development with projected high resolution climate data in Korea far 2011-2100, which was geospatially interpolated from the 25 km gridded data based on the IPCC SRES A2 emission scenario. Satellite remote sensing data were used to pinpoint the rice-growing areas, and corresponding climate data were aggregated to represent the official 'crop reporting county'. For the simulation experiment, we used a CERES-Rice model modified by introducing two equations to calculate the leaf appearance rate based on the effective temperature and existing leaf number and the final number of leaves based on day-length in the photoperiod sensitive phase of rice. We tested the performance of this model using data-sets obtained from transplanting dates and nitrogen fertilization rates experiments over three years (2002 to 2004). The simulation results showed a good performance of this model in heading date prediction [$R^2$=0.9586 for early (Odaebyeo), $R^2$=0.9681 for medium (Hwasungbyeo), and $R^2$=0.9477 for late (Dongjinbyeo) maturity cultivars]. A modified version of CERES-Rice was used to simulate the growth and development of three Japonica varieties, representing early, medium, and late maturity classes, to project crop status for climatological normal years between 2011 and 2100. In order to compare the temporal changes, three sets of data representing 3 climatological years (2011-2040, 2041-2070, and 2071-2100) were successively used to run the model. Simulated growth and yield data of the three Japonica cultivars under the observed climate for 1971-2000 was set as a reference. Compared with the current normal, heading date was accelerated by 7 days for 2011-2040 and 20 days for 2071-2100. Physiological maturity was accelerated by 15 days for 2011-2040 and 30 days for 2071-2100. Rice yield was in general reduced by 6-25%, 3-26%, and 3-25% per 10a in early, medium, and late maturity classes, respectively. However, mid to late maturing varieties showed an increased yield in northern Gyeonggi Province and in most of Kwangwon Province in 2071-2100.

• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.4
• /
• pp.420-430
• /
• 2005

This study was performed to change the hydrophilic $NH_4Y$-zeolite to the hydrophobic one for removal of VOCs by removing the $Al^{3+}$ in the zeolite-structure to increase the Si/Al ratio, for which the three pelleted $NH_4Y$-zeolite samples were contacted separately with the steam of $400^{\circ}C$, $500^{\circ}C$ and $600^{\circ}C$, respectively, in a stainless steel column for 4 hours. Then extraction of the ex-structure aluminum of the hydrolyzed zeolites with the nitric acids of 0.25, 0.50, 0.75, and 0.10 M at $90^{\circ}C$ in 500 mL-flasks, respectively, according to steam temperature were followed. XRD analysises of the dealuminated zeolites showed that the peaks of the zeolites that had been hydrolyzed with the steams of both $500^{\circ}C$ and $600^{\circ}C$ are distorted more with the increase of the concentration of nitric acid used for extraction of the ex-structure aluminums, however, those hydrolyzed with steam of $400^{\circ}C$ became amorphous phase when treated with the all nitric acids of four concentrations. Also the EDX analysises showed that the BET surface areas and TPVS of the zeolites that had been hydrolyzed with the steam of $600^{\circ}C$ were increased with the concentration of the nitric acid when the nitric acids of 0.25 M and 0.5 M had been used but decreased when the nitric acids of 0.75 M and 1.0 M had been used. These results led to the conclusion that both the $600^{\circ}C$ and $500^{\circ}C$-steam and the 0.5 M-nitric acid are appropriate to change the hydrophilic $NH_4Y$-zeolites to the hydrophobic one, which were proven by the measurement of the benzene and tolune-adsorbing capacities showing the same trend as the BET surface area and TPV The Si/Al ratios and water-adsorbing capacities of the dealuminated zeolites were increased and decreased, respectively, with the concentration of the nitric acids so that it showed that the hydrophobicity is increased.