• Magazine of the Korean Society of Agricultural Engineers
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• v.19 no.1
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• pp.4279-4295
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• 1977

Two types of model were established in order to product the soil moisture content by which information on irrigation could be obtained. Model-I was to represent the soil moisture depletion and was established based on the concept of water balance in a given soil profile. Model-II was a mathematical model derived from the analysis of soil moisture variation curves which were drawn from the observed data. In establishing the Model-I, the method and procedure to estimate parameters for the determination of the variables such as evapotranspirations, effective rainfalls, and drainage amounts were discussed. Empirical equations representing soil moisture variation curves were derived from the observed data as the Model-II. The procedure for forecasting timing and amounts of irrigation under the given soil moisture content was discussed. The established models were checked by comparing the observed data with those predicted by the model. Obtained results are summarized as follows: 1. As a water balance model of a given soil profile, the soil moisture depletion D, could be represented as the equation(2). 2. Among the various empirical formulae for potential evapotranspiration (Etp), Penman's formula was best fit to the data observed with the evaporation pans and tanks in Suweon area. High degree of positive correlation between Penman's predicted data and observed data with a large evaporation pan was confirmed. and the regression enquation was Y=0.7436X+17.2918, where Y represents evaporation rate from large evaporation pan, in mm/10days, and X represents potential evapotranspiration rate estimated by use of Penman's formula. 3. Evapotranspiration, Et, could be estimated from the potential evapotranspiration, Etp, by introducing the consumptive use coefficient, Kc, which was repre sensed by the following relationship: Kc=Kco$.$Ka＋Ks‥‥‥(Eq. 6) where Kco : crop coefficient Ka : coefficient depending on the soil moisture content Ks : correction coefficient a. Crop coefficient. Kco. Crop coefficients of barley, bean, and wheat for each growth stage were found to be dependent on the crop. b. Coefficient depending on the soil moisture content, Ka. The values of Ka for clay loam, sandy loam, and loamy sand revealed a similar tendency to those of Pierce type. c. Correction coefficent, Ks. Following relationships were established to estimate Ks values: Ks=Kc-Kco$.$Ka, where Ks=0 if Kc,=Kco$.$K0$\geq$1.0, otherwise Ks=1-Kco$.$Ka 4. Effective rainfall, Re, was estimated by using following relationships : Re=D, if R-D$\geq$0, otherwise, Re=R 5. The difference between rainfall, R, and the soil moisture depletion D, was taken as drainage amount, Wd. {{{{D= SUM from { {i }=1} to n (Et-Re-I+Wd)}}}} if Wd=0, otherwise, {{{{D= SUM from { {i }=tf} to n (Et-Re-I+Wd)}}}} where tf=2∼3 days. 6. The curves and their corresponding empirical equations for the variation of soil moisture depending on the soil types, soil depths are shown on Fig. 8 (a,b.c,d). The general mathematical model on soil moisture variation depending on seasons, weather, and soil types were as follow: {{{{SMC= SUM ( { C}_{i }Exp( { - lambda }_{i } { t}_{i } )+ { Re}_{i } - { Excess}_{i } )}}}} where SMC : soil moisture content C : constant depending on an initial soil moisture content $\lambda$ : constant depending on season t : time Re : effective rainfall Excess : drainage and excess soil moisture other than drainage. The values of $\lambda$ are shown on Table 1. 7. The timing and amount of irrigation could be predicted by the equation (9-a) and (9-b,c), respectively. 8. Under the given conditions, the model for scheduling irrigation was completed. Fig. 9 show computer flow charts of the model. a. To estimate a potential evapotranspiration, Penman's equation was used if a complete observed meteorological data were available, and Jensen-Haise's equation was used if a forecasted meteorological data were available, However none of the observed or forecasted data were available, the equation (15) was used. b. As an input time data, a crop carlender was used, which was made based on the time when the growth stage of the crop shows it's maximum effective leaf coverage. 9. For the purpose of validation of the models, observed data of soil moiture content under various conditions from May, 1975 to July, 1975 were compared to the data predicted by Model-I and Model-II. Model-I shows the relative error of 4.6 to 14.3 percent which is an acceptable range of error in view of engineering purpose. Model-II shows 3 to 16.7 percent of relative error which is a little larger than the one from the Model-I. 10. Comparing two models, the followings are concluded: Model-I established on the theoretical background can predict with a satisfiable reliability far practical use provided that forecasted meteorological data are available. On the other hand, Model-II was superior to Model-I in it's simplicity, but it needs long period and wide scope of observed data to predict acceptable soil moisture content. Further studies are needed on the Model-II to make it acceptable in practical use.

• Journal of Animal Science and Technology
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• v.47 no.5
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• pp.867-876
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• 2005

The microbial contamination of ice cream product commercially available in Korea was determined using ice bar, ice cream, ice milk and non-milk fat ice cream. Irradiation effect on enhancement of microbiological safety was also investigated at doses of 1, 3, and 5 kGy. In all products, yeast and molds were not detected, however, total aerobic and coliform bacteria were detected at 1-2 and 1-1.5 Log CFU/g level, respectively. According to the different flavor used in ice cream, total aerobic bacteria were detected as 2.30, 2.90, and 3.32 Log CFU/g level in vanilla, chocolate, and strawberry ice cream, respectively. Yeast and mold was not detected in vanilla ice cream but 2.30 and 2.70 Log CFU/g in chocolate and strawberry ice cream, respectively. Coliforms were also detected 1-2 Log CFU/g in the ice cream with different flavors. Listeria inocua and Escherichia coli were detected from 3 commercial samples but Salmonella spp. was not detected using API kit. Gamma irradiation significantly reduced the level of the contaminated total aerobic bacteria, yeast and molds and coliform population in the ice creams. These results indicated that irradiation(5kGy or less) is effective to ensure safety of ice cream.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.659-666
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• 2004

This study was conducted to assess objective and subjective meat quality traits for imported chilled beef with a high degree of marbling in longissimus muscle with reference to Hanwoo beef Muscle samples of four Wagyu, four Angus, four Hanwoo grade 1, and three Hanwoo grade 3 were purchased from a commercial beef market. The meats had intramuscular fat content of approximately 22, 8, 13 and 4%, and aged for 31, 71, 14 and 14 days, respectively. Imported beef showed a significantly(P<0.05) lower WB-shear force than Hanwoo. However, the instrument measurement did not reflect sensory tenderness and juiciness, which were similar between the four groups. On the other hand, Hanwoo beef showed significantly(P<0.05) favorable flavor intensity. This was likely an indication of more a desirable eating quality for Hanwoo beef, regardless of the level of intramuscular fat content. Discriminant functions of C18: 0, C18: In-7, C18: In-9, C20: 3n-6, C20 : 4n-6 and total n-3 polyunsaturated fatty acids classified the domestic and foreign beef products at 100%, despite a noticeable difference between two groups existed only in C18:0. Principle component analysis indicated that subjective flavor intensity was negatively related to C18: 0 and C18: ln-7. The result indicated that C18: 0 could be a possible candidate fatty acid for difference in flavor intensity between two beef groups. The current study demonstrated that the domestic product was more acceptable for Korean consumers. However, it was not identified whether the result was associated with breed, feeding regime, or ageing time. Further studies are required for breed specification in terms of sensory characteristics and consumer preference.

• Applied Biological Chemistry
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• v.18 no.1
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• pp.30-41
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• 1975

A substituted diphenyl ether herbicide(MC-4379) was studied on the decomposition by some environmental factors; sunlight, microorganisms, and the crude enzyme in rice plant extract. All the decomposition products were confirmed by means of TLC, GLC, and IR. The parent compound and the decomposition products were put to the test for the effect on the growth of some plants. The results obtained are summarized as follows: 1. Photolysis Amino-MC-4379, 2,4-dichloro-3'-carboxyl-4'-nitrodiphenyl ether, Nitrofen, 2,4-dichloro-3'-carboxyl-4'-amino-diphenyl ether, amino-Nitrofen, 3-carboxymethyl-4-nitrophenol, p-nitrophenol, p-aminophenol, etc. were confirmed as photoproducts, in addition to a relatively small amount of an unknown compound. It was confirmed that the solution-phase photolysis of MC-4379 was accelerated much more by the aid of a photosensitizer benzophenone. 2. Degradation by the crude extract of germinating rice seeds Nitrofen was confirmed as a major degradation product, in addition to a relatively small amount of and unknown compound. Most of the parent compound remained unchanged. 3. Degradation by microorganisms Nitrofen and amino-MC-4379 were confirmed as the major products. in addition to a small amount of an unknown compound. 4. The germinating rice seeds and soybean were grown in the 1,000 ppm emulsions of some chemicals, respectively. The effect on rice plant growth was in the inhibitory order of p-nitrophenol > C-6989> Nitrofen > amino-Nitrofen > MC-4379. The effect on soybean was in the order of Nitrofen > amino-Nitrofen > MC-4379. Two weeds, Amantus blitum and Setaria viridis were grown in the 500 ppm emulsions containing the compounds, respectively. After incubation for 3 days, it was observed that all the shoots had been dead.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.1
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• pp.23-28
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• 2011

Resveratrol has been associated with reduced cardiovascular disease and reduced cancer risk. This phytochemical has been reported in a number of plant species including grapes, peanuts and pine trees in response to stress such as fungal infection, heavy metal ions or UV irradiation. The objective of this study was to determine the resveratrol contents in leaves of mulberry varieties at different collecting times. Quantitative analysis of 16 cultivars showed a range of $102{\sim}466{\mu}g/100g$ on dry weight basis (which is equivalent to $25{\sim}116.5{\mu}g/100g$ on fresh weight basis). Resveratrol contents in mulberry leaves was higher in autumn than spring, and higher in fully matured leaves than in juvenile leaves. Among the tested samples, 'Kaeryangppong', 'Sugeppong' and 'Cheongilppong' collected in the middle of October showed high resveratrol contents of $838{\mu}g/100g$, $803{\mu}g/100g$, $800{\mu}g/100g$ on dry weight basis, respectively. Especially mulberry leaves dried in the shade showed of $1,030{\mu}g/100g$ on dry weight basis in resveratrol content, this result may contribute to utilization of mulberry leaves.

• Journal of Dairy Science and Biotechnology
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• v.33 no.2
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• pp.129-137
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• 2015

Diabetes mellitus type 2 is a metabolic disorder that is characterized by hyperglycemia (high blood sugar level) in the context of insulin resistance and relative lack of insulin. Recently, much scientific evidence has shown that the risk of diabetes mellitus type 2 could be reduced by dairy intake. A significantly strong relationship has been noted between this disease and dairy intake. In particular, from the different types of fat in dairy foods that were reported to have a beneficial impact, low-fat dairy foods have been found to have the best effect with respect to reducing the risk of diabetes mellitus type 2. Therefore, the role of specific components of dairy foods, such as calcium, vitamin D, dairy fat, and trans-palmitoleic acid, which could be responsible for this effect and for the positive effect of dairy foods in obesity and metabolic syndrome, needs to be identified. There is a strong and relatively consistent body of accumulating evidence indicating that dairy foods may significantly reduce the risk of diabetes mellitus type 2, likely in a dose-response manner. Dairy recommendations should be an essential part of public health guidance, and identifying strategies to increase dairy food consumption to optimal levels is of utmost importance. Hence, this review summarizes various positive effects of dairy foods with respect to reducing the risk of diabetes mellitus type 2, based on available evidence, and discusses the need for further research on preventing or decreasing the risk of diabetes mellitus type 2.

• Korean Journal of Environmental Agriculture
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• v.19 no.1
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• pp.32-37
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• 2000

Because the household garbage had high water contents, it is difficult to compost it without an additive. Therefore, this study was performed to investigate possibility of using the waste newspapers as a humidity conditioner for the household garbage composting. The maximum temperature was $66.0^{\circ}C$ in spring, $69.2^{\circ}C$ in summer, $60.9^{\circ}C$ in fall and $56.0^{\circ}C$ in winter for composting periods. The seasonal pH value reached around 8.5 after 1 week and then repeated fluctuation at the narrow range in spring and fall, while it was stabilized at the range of $8{\sim}9$ after increasing to 8.5 after 1 week in winter. The water content was reduced little in winter, while decreased significantly in the other seasons. The water content after 8 weeks was 22.2% in spring, 47.6% in summer, 25.5% in fall and 72.5% in winter. The mass was reduced rapidly during the first week of each season, but it did not show much decrease. The volume reduced after 8 weeks to 59%, 32%, 27%, and 34% in spring, summer, fall and winter respectively. Organic matter content decreased over the four seasons. Nitrogen contents were in the range of 0.7% to 2.2% during the four seasons. The contents of inorganic compounds based on dry matyter were in the range of $0.94{\sim}2.59%\;P_2O_5$, $1.23{\sim}1.87%\;CaO$, $0.37{\sim}0.46%\;MgO$, $0.55{\sim}1.98%\;K_2O$. Concentration of heavy metals(Hg, Cd, Pb, Cu, Cr, Zn, As) based on dry matter were less than the limiting value of the by-product compost.

• Korean Journal of Environmental Biology
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• v.32 no.3
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• pp.168-175
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• 2014

In order to understand the phytoplankton community structure based on their cell size duringlow water temperature periods, we studied 10 stations in the East Sea, Korea on March, 2012. The minimum standing crops of total phytoplankton were $3.4{\times}10^6cells\;L^{-1}$ at the station 5. The maximum values were $7.6{\times}10^6cells\;L^{-1}$ at the station 8, which is two times the amount of the minimum. The carbon mass at the station 4 ($6.3{\times}10^8pg\;L^{-1}$) was more than forty times higher compared with station 5 ($0.08{\times}10^8pg\;L^{-1}$). From these results, we found a significant difference between standing crops and carbon mass which might have caused due to their differences in community structure and cell size. Therefore, we considered the types of plankton biomass to estimate the primary product in the specific location and/or time. The phytoplankton communities were classified in 3 types: microplankton (> $20{\mu}m$), nanoplankton (< $20{\mu}m$) and picoplankton (< $2{\mu}m$). In the case of picoplankton, various morphological types were observed during the study period. These various picoplankton species were further classified as S (spherical), SF (spherical&flagella), O (oval), OF (oval&flagella) or R (rod) type, and we analyzed their community structure based on these categories. The picoplankton was found to be the most dominant type at 8 stations and S type as the most popular. The picoplankton seems to be the significant organism in the marine ecology during low water temperature periods in the coastal waters of East Sea. Therefore, picoplankton \;-with scientific surveys can be considered as the database for their identification. In conclusion, we suggest that cell size of the phytoplankton would be the best criteria to accurately analyze their community structure and to reveal groups having more ecological influence.

• Journal of Food Hygiene and Safety
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• v.30 no.2
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• pp.166-172
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• 2015

This study was performed to develop treatment method for reducing microbial contamination on Daruma (a semi-processed product of seasoned and dried squid) by combination of strong acidic hypochlorous water (SAHW) and ultrasonic waves (UW). The available chlorine concentration, oxidation reduction potential (ORP) and pH of SAHW were $69.67{\pm}0.58ppm$, $1071.33{\pm}4.16mV$ and 2.79, respectively. The 1.49 log CFU/g of viable cell count and 1.32 log CFU/g of Staphylococcus aureus was reduced, and Escherichia coli was reduced below detection limit when the Daruma was treated with 20 times (w/v) of sodium hypochlorite solution (SHS) for 120 min. The 3.62 log CFU/g of viable cell count and 3.22 log CFU/g of Staphylococcus aureus was reduced, and Escherichia coli was reduced below detection limit when the Daruma was treated with 20 times (w/v) of SAHW for 120 min. The antibacterial effects of SAHW were stronger than those of SHS at same available chroline concentration. SAHW treatment after washing strongly alkalic electrolyzed water (SAEW) showed better bactericidal effects than SAHW treatment only. The 4.0 log CFU/g of viable cell count was reduced, S. aureus was reduced below regulation limit (Log 2.0 CFU/g), and E. coli was reduced below detection limit when the Daruma was treated with 20 times (w/v) of SAHW for 90 min after washing with 20 times (w/v) of SAEW for 60 min. The viable cell number was reduced below detection limit and S. aureus was reduced below regulation limit when the Daruma was treated with 20 times (w/v) of SAHW for 60 min in ultrasonic washer. E. coli was reduced below detection limit when the Daruma was treated with 20 times (w/v) of SAHW for 10 min in ultrasonic washer. These results suggest that combination of SAHW and UW may be a good technique to reduce the microbial contamination in daruma.

• The Korean Journal of Food And Nutrition
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• v.19 no.3
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• pp.243-253
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• 2006

This study was designed to investigate the feasibility of utilizing concentrates of sunmul(soybean curd whey), the waste by-product of soybean curd processing, as functional food ingredients. Sunmul was concentrated by nanofiltration fo11owing ultrafiltration and then freeze-dried. The oil adsorption capacity of the nanofiltraion(NF) powder(97.33g/100g) was similar to that of sunmul powder(94.17g/100g), but was lower than that of ISP(isolated soy protein). However, the water holding capacity of NF powder could not be determined because the NF powder completely dissolved in water. The protein solubilities of sunmul powder and ISP in distilled H$_{2}$O, 0.1M and 0.5M NaCl were lowest at pH 4.0 and increased at more acidic or alkaline conditions. However, the protein solubility of NF powder was at its minimum at pH 6.0 and increased at more acidic or alkaline conditions. Emulsifying activity indexes of NF powder in 4% and 6% solution were minimal at pH 4.0 and 6.0, respectively, which were 3 to 8 times lower than that of sunmul powder. The emulsion stability of 4% sunmul solution was lowest at pH 4.0, but that of NF powder was highest at pH 5.0 and decreased at more acidic or alkaline conditions at all concentrations of solution. The total free amino acid contents of protein in sunmul, and NF power were 99.07 and 2,110.10mg%, respectively, and NF powder exhibited especially high threonine content. Rapid viscosity analysis of dough with 1 to 5% added NF powder demonstrated that all of the peak and final viscosities decreased with increasing NF powder concentration compared to the control.