• Korean Journal of Soil Science and Fertilizer
• /
• v.16 no.4
• /
• pp.372-381
• /
• 1983

A laboratory experiment was performed to investigate the effects on redox potential of submerged soil by application of CNP herbicide (2, 4, 6-Trichlorophenyl-4-Nitrophenyl ether) with or without rice straw. Two soils, sandy loam and clay loam textured, were incubated for sixty days at a constant temperature, $25^{\circ}C$. Sampling and analysis of pH, Eh and nitrogen mineralization were carried out during the incubation. The results were summarized as follows. 1. The CNP application decreased redox potential and increased soil pH. The higher the concentration of applicated CNP was, the effects on soil Eh and pH were higher. When rice straw was used with CNP, the Eh of soil remarkably decreased, but seperating the individual effects of rice straw and CNP was impossible in this study. 2. Ammonification increased as the concentration of applied CNP increased regardless of rice straw application or not. It was higher in sandy loam soil than clay loam soil. 3. Nitrification decreased as the concentration of applied CNP increased, especially in the sandy loam soil. Rice straw application reduced nitrification.

• Korean Journal of Soil Science and Fertilizer
• /
• v.25 no.3
• /
• pp.220-230
• /
• 1992

Soil temperature is one of the important environmental factors which control all the physical, chemical and biological processes in soil including germination and root growth of plants and other organisms living in the soil ecosystem. Soil water and nutrient availability and mobility are temperature dependent. Soil temperature change is depended primarily upon energy exchange in soil surface, meteorological variance and physical properties of the soils which are closely related to heat transfer mechanism. In this study physical properties including bulk density, soil texture and organic matter content were measured and thermal diffusivity on the soils was calculated. Soil samples from the 66 meteorological stations under the Korea Meteorology were collected and the physical parameters were measured. To obtain relationship between thermal diffusivity and soil water content a heat probe thermal diffusivity measurement apparatus was designed and used in this experiment. According to the survey on soil physicsal properties on the 66 meteorological stations, the 52% of the surface soil texture were sandy loam and laomy sand or sand, 38% were loam and silty loam, and 10% were clay loam and silty clay loam. The bulk density which was closely related with thermal properties showed average of $1.41g/cm^3$ for sandy soils, $1.33g/cm^3$ for loam and silty loam soils, and $1.21g/cm^3$ for clay loam and silty clay loam soils. The apparent thermal diffusivity of the upper layer from 0 to 30cm ranged from 1.16 to $8.40{\times}10^{-3}cm^3/sec$ with average of $3.53{\times}10^{-3}cm^3/sec$. The apparent thermal diffusivities of the Jeju soils of which organic matter contents were high and the bulk densities were low were near $2{\times}10^{-3}cm^3/sec$. The thermal diffusivity of snow measured in Chuncheon ranged from 0.822 to $2.237{\times}10^{-3}cm^3/sec$. The damping depth calculated from the thermal diffusivity ranged from 5.92 to 13.65cm for daily basis and 124 to 342cm for yearly basis. The significant regression equation to estimate thermal diffusivity with bulk density and soil water content was obtained by the heat probe in laboratory.

• Korean Journal of Soil Science and Fertilizer
• /
• v.25 no.1
• /
• pp.62-69
• /
• 1992

A series of laboratory experiment was conducted to find out the effects of physico-chemical, microbiological and commercial inhibitors on the odorous gas evolution in the fermentation of livestock feces. The results obtained were summarized as follows. 1. The rate and amount of evolution of gas were the highest at 7 days after incubation, thereafter gradually decreased until 24 days after incubation. 2. The rate and amount of gases were evolved in order of $CO_2>N_2O>CH_4>NH_3>N_2S$, respectively. 3. The highest amount of methane gas was evolved from the poultry feces, those of carbon dioxide and nitrous oxide were evolved from the pig feces, and that of hydrogen sulfide was dominantly evolved from the cattle feces. 4. Negative correlation were obtained between the total amounts of $NH_3$ and $CH_4$, $CO_2$ and $CH_4$, $N_2O$ and $CH_4$, $N_2O$ and $CH_4$, while positive correlations were obtained between the amounts of $CO_2$ and $N_2O$, $CO_2$ and $NH_3$, and $NH_3$ and $N_2O$, respectively. 5. There was no significantly inhibiting effect obtained that the application of commercial gas inhibitor as VK 88. On the other hand there was significantly inhibiting effect obtained when application of fertile paddy soil and photosynthetic bacteria to the fermentation of livestock feces.

• Journal of the Korean earth science society
• /
• v.26 no.6
• /
• pp.524-540
• /
• 2005

This study has focused on the amount of evaporites and geochemical characteritics of evaporites from the acid mine drainage and on the variation of constituents in acid mine drainage during evaporation. The various colors of evaporites are frequently observed at the rock surfaces contacting acid mine drainage. In order to produce evaporites in the laboratory, acid mine drainages were sampled from the abandoned mine areas (GTa, GTb, GH and GB) and air-dried at room temperature. During the evaporation of acid mine drainages, TDS, EC values and the concentrations of major and minor ions increased, whereas ER and DO values decreased with time. The concentration of Fe increased gradually with evaporation time in the GTb and GB, whereas GH founded in one day but rapidly not detected in the other day after due to removal of Fe by formation-precipitation of amorphous Fe hydroxide. The amounts of the evaporites were produced in amounts of 4 g (GTa), 5 g (GB), 15 g (GH), and 24 g (GTb) from 4 liter of acid mine drainage after 80 days of the evaporation, respectively. In linear analysis from the products with the parameters which are the EC, TDS, salinity, ER, DO and pH contents in field, the determination coefficients were 0.98, 0.99, 0.98, 0.88, 0.89, and 0.25 respectively. If we measure the parameters in field, it would be easy to estimate the amount of evaporites in acid mine drainage. Gypsum and epsomite were identified in all of the evaporites by x-ray powder diffraction studies. Evaporite (GTb) was heated at 52, 65, 70, 95, 150, 250, and 350oC for one hour in electrical furnaces. Gypsum, $CaSO_4\cdot1/2H_2O$ and kieserite were identified in the heated evaporite by XRD. With increased heating temperature, the intensity of the peak at $7.66/AA$ (diagnostic peak of gypsum), the peak at 5.59A ($CaSO_4{\cdot}1/2H_2O)$ and the peak at $4.83{\AA}$ (kieserite) decreased in x-ray diffraction due to dehydration. In the SEM and EDS analysis for the evaporite, gypsum of well-crystallized, radiating cluster of fibrous, acicular, and columnar shapes were observed in all samples. Ca was not detected in the EDS analysis of the flower structures of GTb. Because of that, the evaporite with flower structures is thought to be eposmite.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.45 no.9
• /
• pp.1358-1365
• /
• 2016

The purpose of this study was to verify the drying characteristics of seasoned red pepper sauce and establish optimal drying conditions for far infrared drying of seasoned red pepper sauce. Seasoned red pepper sauce, which was dried by heated air, was used. One kg of seasoned red pepper was spread at thicknesses of 10 and 20 mm and dried by a far infrared dryer until a final moisture content of $15{\pm}0.5%$. The far infrared dryer conditions were air velocity of 0.6, 0.8 m/s and drying temperatures of 60, 70, and $80^{\circ}C$. The drying models were estimated using a determination coefficient and root mean square error. Drying characteristics were analyzed based on factors such as drying rate, color changes, content of capsaicinoids, and energy consumption. The results can be summarized as follows. The drying rate (that is, drying time) tended to be reduced as temperature and air velocity for drying increased. The Page and Henderson models were suitable for drying of seasoned red pepper sauce by a far infrared dryer. Redness decreased after far infrared drying under all experimental conditions. The color difference was 18.18 under the following conditions: thickness 20 mm, temperature $70^{\circ}C$, and air velocity 0.8 m/s. This value was slightly higher than those under other far infrared drying conditions. The capsaicinoid properties of seasoned red pepper sauce decreased under all far infrared drying conditions. The highest capsaicin (19.91 mg/100 g) and dihydrocapsaicin (12.87 mg/100 g) contents were observed at a thickness of 10 mm, temperature of $80^{\circ}C$, and air velocity of 0.8 m/s. Energy consumption decreased with higher temperature, slower air velocity, and thinner seasoned red pepper sauce.

• Journal of Korean Society of Forest Science
• /
• v.87 no.2
• /
• pp.230-238
• /
• 1998

This study was conducted to compare the regeneration of the seedlings under different vegetation types and to identify the presence of allelopathy in Abies koreana(Ak) natural forest in Banyabong Peak(elevation, 1715m), of Mt. Chiri. Twenty quadrats($10m{\times}10m$) were placed in May, 1996 to classify vegetation structure using TWINSPAN. Water-soluble extracts from leaves and soil humus of different vegetation types were collected to test their effects on both seed germination of Ak and mycelial growth of ectomycorrhizal fungi. Phenolic compounds from soil humus were quantified using HPLC. Among the four vegetation types, Sasa borealis(Sb) was found in both Ak-Quercus mongolica(Qm) and Ak-Rhododendron schlippenbachii(Rs) communities. Natural seeding of Ak was $230,000{\pm}90,000seeds/ha$ in 1995 and their germination rate was 25% in an ideal laboratory condition. Density of Ak seedlings less than 5cm in height was 52,000/ha in 1996, while that of seedlings taller than 5cm in height was only 4,000/ha. In the case of Ak-Qm community, density of Ak seedlings with Sb understory was only 7% of the density of seedlings with Rs understary, suggesting the inhibitory effect of Sb. The germination rate of Ak seeds was significantly reduced by leaf extracts of Sb, and Rhododendron mucronulatum var. ciliatum(Rm) and Ak. Soil humus extract of Ak-Qm-Sb subcommunity reduced germination of Ak seeds by 81% and also reduced by 19% the respiration of mycelia of ectomycorrhizal fumgus, Lactarius sp. Among the seven phenolic compounds identified from the soil humus, extract, Ak-Qm-Sb subcommunity contained significantly high content of p-hydroxybenzoic acid, vanillic acid, and syringic acid. Particularly, p-hydroxybenzoic acid was present at 4.2ppm in the Sb roots and at 16.5ppm in the Sb humus, suggesting that it could be the primary allelopathic compound in Abies koreana forests with Sasa borealis understory.

• Investigative Magnetic Resonance Imaging
• /
• v.9 no.1
• /
• pp.30-35
• /
• 2005

Purpose : The purpose of this study is to observe the blood oxygen level dependent (BOLD) contrast changes due to the reaction of human brain at a gustatory sense in response to a salty-taste stimulation. Materials and Methods : Twelve healthy, non-smoking, right-handed male subjects (mean age: 25.6, range: 23-28 years) participated in this salty-taste stimulus functional magnetic resonance (fMRI) study. MRI scans were performed with 1.57 GE Signa, using a multi-slice GE-EPI sequence according to a blood-oxy-gen-level dependent (BOLD) experiment paradigm. Scan parameters included matrix size $128\times128$, FOV 250 mm, TR 5000 msec, TE 60 msec, TH/GAP 5/2 mm. Sequential data acquisitions were carried out for 42 measurements with a repetition time of 5 sec for each taste-stimulus experiments. Analysis of fMRI data was carried out using SPM99 implemented in Matlab. NaCl solution $(3\%)$ was used as a salty stimulus. The task paradigm consisted of alternating rest-stimulus cycles (30-second rest, 15-second stimulus) for 210 seconds. During the stimulus period, NaCl-solution was presented to the subject's mouth through plastic tubes as a bolus of delivered every 5 sec using -processor controlled auto-syringe pump. Results : Insula, frontal opercular taste cortex, amygdala and orbitofrontal cortex (OFC) were activated by a salty-taste stimulation $(NaCl,\;3\%)$ in the fMRI experiments. And dosolateral prefrontal cortex (DLPFC) was also significantly responded to salty-taste stimuli. Activation areas of the right side hemisphere were more superior to the left side hemisphere. Conclusion : The results of this study well correspond to the fact that both insula, amygdala, OFC, DLPFC areas are established as taste cortical areas by neuronal recordings in primates. Authors found that laboratory-developed auto-syringe pump is suitable for gustatory fMRI study. Further research in this field will accelerate to inquire into the mechanism of higher order gustatory process.

• Journal of Korean Ophthalmic Optics Society
• /
• v.18 no.3
• /
• pp.313-320
• /
• 2013

Purpose: This study compared the quantity of phoria for distance by new method with that by existing methods. Methods: For this study, it was selected to two existing phoria measurements, von Graefe and Maddox rod. And new method named "3D polarizing phoria measurement" was designed to measure the quantity of phoria using polarizing glasses and 3D display. Unlike existing measurement using polarized lens, newly considered method measured the quantity of phoria in condition removed perfect binocular fusion using field stop on apparatus and polarized lens. For using new method for distance, it was developed a phoria test chart. It supports three kinds of phoria measurements. Subjects were 12 (male 6, female 6). They had three phoria tests (1 sets) including new method. It was considered the effect of experimental order, so we tested all cases about experimental order. The number of cases was 6 sets, and the sample size in this experiment was 72 sets. For removing binocular fusion, lighting of the laboratory that was below 10 lx and the background color of phoria test chart was dark, RGB=(20, 20, 20). Results: Subjects were sorted into three groups. Samples with exophoria and orthophoria were 30 sets each, and those with esophoria were 12 sets. The quantity of phoria measured three tests differ from each other like "newmethod < von Graefe < Maddox rod", and there were statistically significant difference each other. Conclusions: This study has great significance in the sense that new method was the measurement with naturally removing binocular fusion without dizziness during the tests.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.9
• /
• pp.1350-1356
• /
• 2005

Osteoporosis that is associated with estrogen deficiency in menopause is by far the most common cause of age-related bone loss. Since isoflavone had been reported as a natural substance that minimizes bone loss, we have begun this study to examine the effect of the substance on bone metabolism in ovariectomized rats. Five week-old (n=22) and 25 week-old (n=22) Sprage-Dawley female rats were classified into young (Y) and adult (A) groups. Each group consisted of three subgroups : sham operated group (SH), ovariectomized group (OVX), and isoflavone supplemented group (OVX+ISO 80 mg/kg B.W.). They were fed chow for 9 weeks. The result showed that body weight gain was increased in YOVX in comparison to YSH group, (p<0.05) serum osteocalcin concentration and urinal deoxypyridinoline (DPD) excretion had significantly increased in YOVX more than in YSH group, and significantly decrease in OVX+ISO than in YOVX group (p<0.05). We concluded that soy isoflavones may decrease bone turnover in young rats. However, isoflavone supplement didn't show significant influence on bone metabolism of adult rats.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.28 no.1
• /
• pp.41-57
• /
• 1983

The effect of temperature 'during the reduction division stage on the Indica-Japonica rice varieties were studied in artificial temperature-controlled cabinets (Bioclimatic Laboratory). Varieties used were indica-japonica crosses (Suweon 264, Suweon 258, Milyang 29), indica (IR36, Lengkwang) and japonica rice (Jin-heung). The results obtained from this study are summarized as follows. The most sensitive stage to low temperature, the tetrad stage, was observed in each variety with the following auricle distance: Jinheung, -12cm; IR36, -3cm; Suweon264, -9cm; Suweon258, -3cm; Milyang29, -6cm and Lengkwang, +1cm. The tetrad stage occured when the palea elongation was about 50 to 60% of the final palea length at flowering stage in all varieties. The percentage of degenerated spikelets at tetrad as influenced by low-temperature treatment was very low in Jinheung and Lengkwang, but very high in IR36. In indica-japonica crosses only the 7-days treatments had a very high percentage. Between the 4-day and 7-day treatments as well as among all varieties, clear differences were observed in the low temperature induced sterility of 'special spikelets' (upper position grains at tetrad). In the 7-day treatments except in Lengkwang, all varieties showed very high sterility. It appears that the treatments is over the critical limit for treatment. However in the 4-day treatments, the intervarietal differences in sterility were very clear. In Jinheung, sterility was 46.8%; IR36, 67.6%; Suweon264, 60.9%, Milyang29, 62.2%; Lengkwang, 27.8%. A close relationship was observed between fertility and auricle distance. The lowest fertility of special spikelets was at the tetrad stage and the first contraction phase. Before and after the stage there was an increase in fertility. The palea length elongated nearly in a straight line from the spikelet formation stage to flowering. And there was a high correlation between palea length and auricle distance. distance.