• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.195-195
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• 2017

The water in the crop cultivation shows difference according to the variety of crop, cultivations period and climatic condition. The growth and development, quantity and fruit enlargements are affected by soil water conditions. In previous study, leaf area and photosynthesis are decreased by lower soil moisture. Other research reported that excess moisture condition at vegetative and reproductive growth period in cultivation of soybean caused highest reduction in crop growth rate (CGR) and dry weights of plant parts. In particular, the damage was bigger during vegetative growth stage than reproductive growth period. Soybean (Glycine max (L.) Merill) is useful and popular crop throughout the world. It is very popular crop in Korea, China, Japan and other Asian countries. Soybeans used in various way including soybean sprouts, paste, soymilk, oil and tofu. Two soybean cultivars grown in four different irrigation conditions were determined for physiological responses. In this study, we examined leaf area (LA), leaf dry weight (LDW), specific leaf area (SLA), root dry weight (RDW) and shoot height (SH) in different water conditions. 50mL/9day irrigation periods showed the lowest contents in LA, LDW, RDW, SH. Water deficit caused increase of leaf Water saturation deficits (WSD), Cheongjakong 3 and Taekwangkong showed increase of leaf water saturation deficits (WSD) in drought conditions and leaf water potential and stomatal conductance were decreased. Photochemical efficiency was decreased in 50mL/1day irrigation condition while, there was decrease of growth and development in 50mL/9day with drought.

• Asian Journal of Atmospheric Environment
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• v.10 no.3
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• pp.146-155
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• 2016

Spatial and temporal variations of mercury, including dry and wet deposition fluxes, were assessed over Northeast Asia, targeting the Yellow Sea, using meteorology and chemistry models. Four modeling periods, each representative of one of the four seasons, were selected. Modeling results captured general patterns and behaviors, and fell within similar ranges with respect to observations. However, temporal variations of mercury were not closely matched, possibly owing to the effects of localized emissions. Modeling results indicated that dry deposition is correlated with wind speed, while wet deposition is correlated with precipitation amount. Overall, the wet deposition flux of $66ng/m^2-day$ was about twice as large as the dry deposition flux of $32ng/m^2-day$, when averaged over the four modeling periods. Dry deposition occurred predominantly in the form of reactive gaseous mercury (RGM). In contrast, RGM accounted for only about two-thirds of wet deposition, while particulate mercury accounted for the remainder.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.255-257
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• 2012

Epoxy resin without any hardener can harden in the presence of hydroxide ions in cement mortars and concretes at ambient temperature. The purpose of present study is to examine the hardening properties of hardener-free epoxy-modified mortars by curing conditions. The hardener-free epoxy-modified mortars using diglycidyl ether of A epoxy resin are prepared with various polymer-cement ratios, and subjected to initial moist/dry curing, initial steam(90℃) curing, initial steam/heat(80℃, 100℃) curing.As a result, degree of hardening of epoxy resin in initial moist/dry cured, initial steam cured and initial steam/heat(80℃) cured hardener-free epoxy-modified mortars is decreased with increasing polymer-cement ratio. However, it is markedly improved with additional dry-curing periods. On the other hand, regardless of the polymer-cement ratio and dry curing periods, degree of hardening of hardener-free epoxy-modified mortars with initial steam/heat(100℃) cure is over 95%.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.6
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• pp.585-594
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• 2000

Through an application of Micrometerorological methods, we conducted measurements of Hg fluxes from Nan-Ji-Do which is well known as one of the major local areal sources in Seoul metropolitan area during Match/April of 2000. In the course of our study, we determined the concentration gradients of total gaseous Hg(between 20 and 2000 cm heights) and combined these data with Micrometerorological components to derive is fluxes. It turned out that emission from and dry deposition to soil surfaces occurred at the ratio of 72:27 from a total of 271 hourly measurements. The validity of measured concentration gradients( or resulting fluxes) was evaluated in terms of percent gradient. Accordingly, about more than 95% of gradient data derived were statistically significant. The mean fluxes of Hg across soil-air interface, when computed using the concentrations gradients and relevant parameters, were found at 253(during emission) and -846ng/$m^2$/h(during dry deposition) The occurrences of abnormalously high exchange rates appear to be the combined effects of enormously high gradient values and high transfer coefficients. While the emissions of Hg occurred constantly during the whole study periods, the occurrences of dry deposition events were observed most intensively during very limited time periods(3/29 and 4/3). The results of our study cleary indicated that the studied area is a strong local areal source, while exhibiting great potential as a major sink simultaneously.

• Journal of the korean veterinary medical association
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• v.43 no.4
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• pp.338-353
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• 2007

• Animal Bioscience
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• v.34 no.4
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• pp.539-545
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• 2021

Objective: Endometritis is a major disease, that causes infertility in cattle, and is usually categorized as clinical or subclinical endometritis (SCE). The nutritional condition during the dry period is important for recovery after the last stage of the lactation period, and for postpartum production and reproduction. This study aimed to clarify the relationship between nutritional and metabolic characteristics in the dry period, and the risk of postpartum SCE. Methods: Multiparous Holstein dairy cows (n = 25, raised in a tied stall) were used. Endometrial cytological analysis was performed around 30 days post-partum, with 5% to 14% polymorphonuclear (PMN) as a cut-off point to define SCE. Serum levels of glucose, non-esterified fatty acids, β-hydroxybutyric acid (BHBA), blood urea nitrogen, total cholesterol, aspartate aminotransferase, γ-glutamyl transpeptidase, calcium, phosphorus, and magnesium were measured in the cows at the dry period to evaluate energy status, protein metabolism, and mineral metabolism. Results: The incidence of SCE in the cows was 60.0% (n = 15/25) and the mean PMN% in postpartum cows diagnosed as SCE was 8.05%±2.6%. Overall, 17 and 8 samples were collected from the cows in the far-off and close-up periods, respectively. The serum concentration of BHBA in the far-off period and serum glucose concentration in the closeup period were correlated with postpartum PMN% (r = 0.62, p<0.01; r = -0.74, p<0.05, respectively). Serum levels of calcium and magnesium in the dry period were associated with the incidence of postpartum SCE (healthy vs SCE cows, p<0.05). Conclusion: Blood levels of glucose, BHBA, calcium, and magnesium in dry periods could be useful parameters for predicting the risk of postpartum SCE. The present study also suggests that management in the close-up period is essential for promoting recovery from calving fatigue.

• Journal of Korea Water Resources Association
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• v.33 no.5
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• pp.519-526
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• 2000

This study is to investigate the recurrence possibility of consecutive dry years such as the long dry period around 1900 in the annual rainfall data at Seoul station. The truncation levels, as the criterion for the dry years, are decided such as to make the occurrence of dry years follow the Poissonian distribution, which assures independent occurrence of dry years. For the truncation level of mean-0.5stdv, the occurrence of dry years is found to satisfy the Poissonian distribution weakly with 99% significance level, but for those of mean-0.75stdv and mean-stdv with 95% significance level. For these truncation levels, the long dry period around 1900 is divided into several short consecutive dry years. The Poisson process has then been applied to derive the occurrence probability of consecutive dry years. For the truncation level of mean-0.75stdv or below, the Poisson process was found to reproduce similar occurrence probabilities to the observed. Especially for the lowest truncation level used in the study (mean-stdv), we could see that the occurrence probability of consecutive dry years estimated for the data collected before the long dry period around 1900 was higher that those for the data collected after the long dry period, thus, it could be concluded that the possibility of long dry periods is decreasing recently.cently.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.2
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• pp.85-90
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• 1989

Forty bull calves of Sahiwal crosses were fed either urea treated or untreated rice straw with 4 levels of Gliricidia (0, 1, 2, and 4 kg fresh material). Dry matter intake (DMI) of straw and Gliricidia was measured during 2 periods. Straw intakes in period 1 and 2 were significantly different (P<0.001). Supplementation of Gliricidia depressed the DMI of straw during the second period (P<0.01), but not in the first period. Urea-ammonia treatment increased straw intake and total intake in both periods, but the increase in dry matter digestibility (DMD) of the ration was not significant (P>0.05). Liveweight gain (LWG) was increased significantly, both by urea ammonia treatment (P<0.01) and by supplementation with Gliricidia (P<0.001). Animals on treated straw gained on an average $137\;g{\cdot}d^{-1}$ more than those on untreated straw.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2001.10a
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• pp.441-444
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• 2001

This study describes the characteristics of concentrations of pollutants such as tolal nitrogen(T-N), total phosphrous(T-P), and chemical oxgen demand(COD) at paddy areas during 2-year dry irrigation periods. Most of pollutants concentrations in drainage water are lower than those in irrigation water after early July due to large uptake of pollutants by rice crop and denitrification. For drainage water, the concentrations of pollutants are constant irrespective of discharges and the average T-N/T-P ratios water range from 14 to 44, suggesting that phosphrous is limiting.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.4
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• pp.467-473
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• 2001

The internal humoral factors in the central regulation of dry feed intake during water deprivation in sheep were investigated by measurement of cerebrospinal fluid (CSF) constituents. Five animals were fed dried alfalfa chaff for 2 hours once a day. Sheep in the water deprivation treatment were deprived of water for 28 hours, while the sheep in the control treatment were given free access to water. During the first hour of the 2 hour feeding period, a rapid reduction in blood volume occured in both treatments (water deprivation and free access to water). The CSF concentrations of Na, Cl and osmolality during the second hour of the 2 hour feeding period in both treatments were greater (p<0.01) than those during the first hour. The drinking behaviors in sheep were concentrated during the second hour of the 2 hour feeding period in periods of free access to water. Water intake during feeding in periods of free access to water was 1110 ml/2 h. The levels of increase in CSF osmolality with feeding during water deprivation were greater (p<0.01) than during periods of free access to water. The changes in CSF osmolality with feeding during water deprivation produced more vigorous thirst sensations in the brain compared to during periods of free access to water. The eating rates for the first hour of the allotted 2 hour feeding period were the same under both treatments. However, the eating rates for the second hour during water deprivation periods decreased significantly (p<0.05) compared to those during periods of free access to water. The decreased eating rates for the second hour during water deprivation may be due to the vigorous thirst sensations produced in the brain. The results suggest that the increase in CSF osmolality with feeding during water deprivation acts as a thirst and satiety factor in brain mechanisms controlling feeding to decrease dry feed intake in water-deprived sheep.