• Korean Journal of Soil Science and Fertilizer
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• v.24 no.4
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• pp.241-247
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• 1991

Electric charge characteristics of volcanic ash soils in Cheju Island were investigated. For this study, soils of toposequence distributed along the sourthern slope of Mt. Halla, and the major soil groups such as dark brown soils, very dark brown soils, black soils, and brown forest soils were collected and analyzed for extratable acidity, KCl ext. Al, CEC, base saturation, permanent charge and variable charge, etc.. Weolpyeong and Yongheung soils developed on the lower elevations have high $NH_4OAc$ ext. bases, permanent charge and base saturation, and relatively low ext. acidity, CEC and variable charge. For other soils, whose colloidal fractions are dominated by allophane or Al-humus complexes, ext. acidity, CEC, variable charge, and variable charge ratio were very high, and $NH_4OAc$ ext. bases, permanent charge, and base saturation were very low. These trends were especially prominant in the surface. horizons of black soils and brown forest soils dominated by Al-humus complexes. Ext. acidity, CEC($NH_4OAc$), CEC(sum of cations), and variable charge strongly correlated with pyrophosphate ext. carbon. Very dark brown soils and cinder cone soils dominated by allophane showed low KCl ext. Al and relatively high pH, despite their very low base saturation.

• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.4
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• pp.219-223
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• 2002

This study investigated effects of bark acidity, leaf acidity and water soluble sulfur contents by SO$_2$, 1-2 seedling of Prunus yedoensis and Ligustrum obtusifolium were treated 5 level (0. 0.5, 1, 2, 4 ppm) of SO$_2$. The tallowing results were obtained; In the case of bark and leaf acidities, pH values decreased as SO$_2$ concentration was high. Prunus yedoensis compare with Ligustrum obtusifolium had high relative susceptibility because rates of increase in bark and leaf acidities were high according to SO$_2$ concentration. Water soluble sulfur contents in the leaves also increased as SO$_2$ concentration was high. Prunus yedoensis compare with Ligustrum obtusifolium had high relative susceptibility because increase rates of water soluble sulfur contents in the leaves were high according to SO$_2$ concentration.

• Journal of Life Science
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• v.7 no.4
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• pp.342-346
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• 1997

This experiment was carried out to clarify the effects of gibberellin(GA) aplication and bagging on repeening and quality in 'Delaware' grape berries. Treatments are 4 plots(2X2 factorial experiment); GA, GA+bagging, bagging and control. The clusters were dipped twice in 100 ppm GA with GA treatment : 10 days before and after the full bloom. The results obtained as follows: 1. GA treatment made the seedless grape berry reduced in the fresh weight but it hastened the ripening period about 2 weeks. 2. Total soluble solid(TSS), viscosity and pH value of berry juice increased with maturation. The concentration of TSS and viscosity were higher in GA treatment plot than GA non-treatment. 3. Berry-hardness, titratable acidity and alcohol inslouble solid(AIS) decreased with maturation. Expically berry-hardness and AIS decreased more greatly in GA non-treatment than GA treatment. 4. The concentration of anthocyanin increased with ripening but pectic substance didn't fluctuate nearly. These of anthocyanin and pectin were higher in GA non-treatment plot than GA treatment. 5. By analysis of factorial experiment GA treatment was highly significant with the $^{o}$Brix/Acidity ratio, juice viscosity and AIS, but high negatively, significant with berry-hardness and berry fresh weight. And it was significant with T S S and negatively, titratable acidity. Bagging was significant with $^{o}$Brix/Acidity ratio and AIS content, but negatively, titratable acidity. 6. Qualitative characters were high correlated with the $^{o}$Brix/Acidity ratio in simple correlation but direct effect by the path-coefficient analysis didn't coincide with simple correlation. The direct effect of pH was large and juice viscosity, the next. And that of berry-hardness was negligible but, AIS, small negatively.

• 보존과학연구
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• s.20
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• pp.21-47
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• 1999

According to damage of papers by the chemical cause, papers become to acidify. Among the 3 kinds of method measuring the acidity of paper, one was nondestructive method measuring the surface of the paper by flat type electrode and the others were destructive methods measuring directly by cold water extract method and hot water extract method. In case of the cellulolytic cultural properties, the latter methods were not applied because those methods must bedissociated papers. To measure the paper acidity nondestructively, we investigated the correlation of the nondestructive method and the destructive methods. The conclusions are as follows. 1) In the relationship of the cold water extract method and the hot water extract method, It was indicated that the pH measured by the hot water extract method was high quality printing paper 0.08, rough printing paper 0.13, and Korean paper 0.29 higher than that by the cold water extract method.2) In the relationship of the cold water extract method and the surface measurement method, It showed that the pH value measured by the cold water extract method was high quality printing paper 1.86, rough printing paper 0.80,and Korean paper 0.58 higher than value that by the surface measurement.3) In the relationship of the hot water extract method and the surface measurement method, It showed that the pH value measured by the hot ABSTRACT water extract method was high quality printing paper 1.78, rough printing paper 0.66, and Korean paper 0.29 higher than that by the surface measurement. From the above-mentioned results, the pH value measured by the surface measurement was need to high about 1.78∼1.86 in high quality printing paper, 0.66-0.80 in rough printing paper, and 0.29∼0.58 in Korean paper and the surface measurement with flat type electrode was very available to measure the acidity of Korean papers actually.

• Journal of dental hygiene science
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• v.21 no.3
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• pp.150-157
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• 2021

Background: Stress as a cause of mental health problems is known to be more prevalent in women than in men and has a negative effect on several aspects of physical health, such as the composition of blood and saliva. This study investigated the relationship of perceived stress with blood cell counts, saliva flow rate, and saliva factors. Methods: We recruited women in their 20s with a high prevalence of stress. Stress was evaluated using the Korean version of the perceived stress scale. Blood tests included white blood cell, hemoglobin, and platelet. We then examined the saliva flow rate and cariogenic bacteria level, acidity, occult blood, buffer capacity, leukocyte level, protein level, and ammonia level using rinse water with the SILL-Ha^Ⓡ saliva test system. Results: In a total of 70 participants, the average age was 21.64 years old, the average perceived stress score was 16.96±4.32, and high levels of stress were reported by 80% of the participants (n=56). The high-stress group had lower hemoglobin levels. In addition, the high-stress group showed a lower saliva flow rate than the low-stress group, and there was a difference in the salivary acidity and buffer capacity. The total perceived stress score showed a positive correlation with acidity and negative correlation with buffer capacity and the hemoglobin level. Conclusion: This study found that stress in female college students might affect the composition of blood and saliva. High levels of stress were positively correlated with the hemoglobin level, saliva flow rate, and acidity and negatively correlated with the buffer capacity.

• Korean journal of food and cookery science
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• v.4 no.1
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• pp.59-63
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• 1988

The changes of acidity, the content of alcohol-insoluble solid (AIS) and pectic substances of Kimchis which were prepared with various garlic contents and fermentation at $21^{\circ}C$ were investigated. Acidity and the content of water soluble pectin of Kimchis increased but the content of AIS and protopectin decreased during the fermentation. As the Kimchis contained high garlic contents compared with the Kimchis deleted garlic, acidity of those rapidly increased but the content of AIS of those slightly decreased with fermentation. In the case of Kimcltis contained high garlic contents, protopectin decreased and water soluble pectin increased with fermentation, but the amount of changes was small.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.4
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• pp.393-402
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• 1999

Precipitation samples were collected by the wet-only sampling method in Iksan in the northwest of Chonbuk from March 1995 to February 1997. These samples were analyzed for the concentration of ion components, in addition to pH and electrical conductivity. The annual mean pH of precipitation was 4.8 and the seasonal trend of pH was shown to be low in Fall and Winter(4.5), middle-ranged in Spring(4.7) and high in Summer(5.0). The frequency of pH below 5.6 was about 71%. The seasonal pattern of pH frequency was found to be different in each season. In the case of the pH less than 5.0, the frequency was higher in Spring, Fall and Winter than in Summer, especially higher in Fall than in other seasons. The concentrations of analysed ions showed a pronounced seasonal pattern. However, major ion species for all seasons were $NH^+_4,;Ca^{2+};and;Na^+$ among cations and $SO^{2-}_4,;Cl^-;and;NO^-_3$ among anions. The major acidifying species appeared to be $nss-SO^{2-}_4;and;NO^-_3$, and the main bases responsible for the neutralization of precipitation acidity were $nss-Ca^{2+};and;NH^+_4$. The potential acidity of precipitation, pAi, was found to be between 3.0 and 5.0 for total samples, while the measured pH was approximately between 3.9 and 7.8. The seasonal trend of pAi showed a decreasing order: Summer (4.3), Winter(4.0), Spring and Fall(3.8). During the Fall, both pAi and pH were especially very low, which indicated that during this period the potential acidity of precipitation was high but the neutralizing capacity was low. For Spring, pAi was very low but pH was slightly high. This was likely due to the large amount of $CaCO_3$ in the soil particles transported over a long range from the Chinese continent that were incorporated into the precipitation, and then neutralized the acidifying species with its high concentraton.

• Journal of the East Asian Society of Dietary Life
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• v.3 no.2
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• pp.107-119
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• 1993

The objeative of this study was to investigate the possibility of estimation of internal quality by observing visible state of strawberry. Several tests such as color("L", "A", H,V,C), degree of blackred ness, opening state of calyx, vitamin C content, brix degree, acidity, freshness, overall quality, chlorophyll content, and anthocyanin content were performend during circulation at 20$^{\circ}C$. Acidity(R=-0.96), chloroph-yll content(r=-0.99), vitamin C content(r=-0.98), freshness(r=-0.96), and overall quality(-0.99), degree of blackredness(r=0.98) and opening state of calyx(=0.98), color saturation(r=0.99), degree of blackredness(r=0.98) and opening state of calyx(=0.98) increased during circulation at 20$^{\circ}C$. in correlation between visible indicators andd internal qualities, "L" valu and brix degree was r=-0.74, "a" and brix degree was r=0.93 Hue and anthocyanin content was r=0.74, value and chlorophyll content, brix degree were r=-0.91, r=-0.77, chroma and brix degree was r=0.96. The correlations between color saturation and vitamin C content(r=-0.96), chlorophyll content(r=-0.98), freshness(r=-0.98), overall quality(r=-0.94), loss of total polyphenol(0.94) and acidity(r=-0.94) showed high correlation. The correlatiions between degree of blackrednes and vitamin C content(r=-0.99), chlorophyll content(r=-0.94), anthocyanin content(=-0.74), freshness(r=-0.97) overall quality (r=-0.95), loss of total polyphenol(r=0.93) and acidity(r=-0.91) chlorophyll content(r=-0.99), freshness(r=-0.98), overall quality(r=-0.92), loss of total polyphenol(r=0.99) and acidity(r=0.83) showed high correlation.

• Journal of the Korean Society of Food Culture
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• v.35 no.5
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• pp.450-458
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• 2020

This study examined the optimal temperature and time conditions to maintain high quality Dongchimi during the fermentation and storage period. Dongchimi was fermented at low (5℃), medium (10 and 15℃), and high (20℃) temperatures until the acidity reached 0.2, 0.3, and 0.4%. respectively. From the consumer's preference test enrolling five consumers, Dongchimi fermented at 15℃ until an acidity of 0.3% (for approximately six days) was evaluated to be the optimal status because of its high score of overall acceptance, taste, and odor of consumers. To determine the optimal storage temperature of fermentation, Dongchimi was stored at three different temperatures (-1, 2, 5℃) for four weeks after fermenting at 15℃ for six days. During the storage period, most of the physicochemical properties (pH, acidity, reducing sugar content, and organic acid) and microbiological properties changed significantly in the 2 and 5℃ groups, resulting in a significant change in descriptive sensory analysis of Dongchimi. These results indicate that fermentation at 15℃ and storage at -1℃ for Dongchimi enables it to maintain the best quality for a long time.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.1
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• pp.75-86
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• 2002

This study was conducted to analyze the change of soil characteristics effect on the condition of urban forest in Sasang parti located near Sasang Industrial Complex. The results of this study are as follows; 1. Soil hardness is increasing from the area of forest, to the entrance, to facilities in that order. Soil acidity pH4.19∼4.23 in Sasang park indicated a high acidity condition. High levers of K, Na, Mg, Ca are shown in the areas composed of high soil hardness. 2. Pinus thunbergii in the overstory tree layer, Alnus japonica in the understory tree layer, and Rhus sylvestris in the shurb layer are shown respectively as dominant species based on the ground survey and the compution of important value. Pinus thunbergii is decreasing, while Alnus japonica and increasing. 3. Oplismenus undulatifolius which has a strong tolerance for air pollution, is shown as a dominant species of herbaceous plants in Sasang park. There are 10 species of Harbaceous in Sasang park compared to 20 species in Molundae park. This shows that deversity in herbaceous plants are imported by air pollution. 4. Species diversity indices of Sasang park is 0.8738∼0.9700 compared to 1.0817∼ 1.233 in Molundae park is due to the good condition of soil environment in addition to air pollution effects. 5. The vitality of Pinus thunbergii is 16.41∼20.42ER in Sasang park, and 12.42∼ 16.81ER, in Molundae park. This shows that tree vitality are impacted by soil characteristics. The regression analysis between tree vitality and soil environment shows the effects of is soil hardness, soil moisture, soil acidity, K, Na, Mg, Ca.