• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.3
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• pp.167-171
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• 2004

The growth of soybean sprout was greatly influenced by watering systems： Fixed watering system (water tub was loaded at ceiling upper of culture box and water was showered by bottom holes) was estimated the better than that of reciprocating watering and tub immersing watering because it could cool down the temperature in culture box and wash the organic substances on the body of sprout. The fixed watering system showed good body color and preventing effect of partial rotting of sprout because it could discharge $\textrm{CO}_2$ gas effectively in culture box and keep the concentration below 5%. The concentration of gases at the bottom (about 30 cm height from basal plate) of culture box in fourth or fifth days was L6% for $\textrm{CO}_2$ and 13-16% for $\textrm{O}_2$, respectively. The optimum gas concentration in culture box was considered to be over 10% for $\textrm{O}_2$ and below 5% for $\textrm{CO}_2$.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.4 no.4
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• pp.79-93
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• 1984

The dissolved air flotation(DAF) has been shown to be efficient process for the removal of algae ftom water. The efficiency of DAF can be affected by the volume ratio of pressurized liquid to sample, the pressure pressurized liquid, the contact time, the appropriate coagulant and its amount, the water temperature, the turbulence of reactor, the bubble size and rising velocity etc. The purpose of this paper is to compare the practical bubble rising velocity with the theoretical one, to investigate the adhesion phenomenon of bubbles and floc, and the influence of bubble size and velocity upon the process. The results through theoretical review and experimental investigation are as follows: Ives' equation is more suitable than Stokes' equation in computation of the bubble rising velocity. The collection of bubble and algae floc is convective collection type and resulted from absorption than adhesion or collision. The treatment efficiency is excellent when the bubble sizes are smaller than $l00{\mu}m$, and the turbulence of reactor is small. In the optimum condition of continuous type DAF the volume ratio of pressurized liquid to sample is 15%, the contact time in reactor is 15 minutes, the pressure of pressurized liquid is $4kg/cm^2$ and the distance from jet needle to inlet is 30cm.

• Journal of Mushroom
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• v.7 no.3
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• pp.115-121
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• 2009

Recently sawdust cultivation of Shiitake mushroom (Lentinula edodes ) is getting increased because log cultivation is getting difficult to get oak logs. It is important to make mycelia browning on the substrate surface in sawdust cultivation. This browned surface plays an important role like as artificial bark of the oak log, which protects the other pests and suppresses water evaporation in the substrate. The period for mycelia browning is so long that the sawdust cultivation of Shiitake mushroom can not spread well into the mushroom farms. In this article we would like to discuss about the effect of environmental condition to the mycelial browning during sawdust bag cultivation for the To reduce the period required for browning of substrates, sawdust substrates was illuminated light with difference intensity. One hundred Lux light illumination was needed for producing normal yield of fruit body but fruit body yield was low and abnormally shaped fruit body was produced when cultured under the dark condition of incubation. Illumination over 200lux is necessary for the successful browning of substrates during incubation. Optimum incubation temperature for browning of substrates and fruiting was $25^{\circ}C$. The treatment of cotton plug with different size to identify the effect of aeration on the browning of substrates and fruiting showed rapid mycelial growth and reduced the periods for browning as the size of cotton plug was bigger. However, yield of fruit body was the highest at 16mm diameter cotton plug as compared to 20mm of that. $CO_2$ content in vessel of substrates was low as the size of cotton plug was bigger during incubation. $CO_2$ content during incubation of substrate was highest in periods between 8 week and 14 week after inoculation of shiitake when substrate was changed color into brown. $C_2H_4$ content in vessel with substrates was highest at 8mm diameter cotton plug and it was increased by order of 12, 16, 20, 0, 4 mm diameter cotton plug during substrate incubation. Sawdust substrate was soaked in cold water for different time to identify soaking effect of sawdust substrate on fruit body yield and activities of enzymes in these substrates were investigated. The fruit body yield was increased up to 40% by soaking substrates in comparison with unsoaked substrates. The soaked substrates showed 165, 175g/1,000ml at treatment of 4 and 15 hours, respectively. Cellulose activities in soaked substrates were not changed with soaking time, but activities of laccase, lignin degradation enzyme, were drastically increased up to 4 times in comparison with unsoaked substrates.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.1
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• pp.23-31
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• 2013

Microwave remote sensing can help monitor the land surface water cycle and crop growth. This type of remote sensing has great potential over conventional remote sensing using the visible and infrared regions due to its all-weather day-and-night imaging capabilities. In this paper, a ground-based multi-frequency (L-, C-, and X-band) polarimetric scatterometer system capable of making observations every 10 min was developed. This system was used to monitor the wheat over an entire growth cycle. The polarimetric scatterometer components were installed inside an air-conditioned shelter to maintain constant temperature and humidity during the data acquisition period. Backscattering coefficients for the crop growing season were compared with biophysical measurements. Backscattering coefficients for all frequencies and polarizations increased until dat of year 137 and then decreased along with fresh weight, dry weight, plant height, and vegetation water content (VWC). The range of backscatter for X-band was lower than for L- and C-band. We examined the relationship between the backscattering coefficients of each band (frequency/polarization) and the various wheat growth parameters. The correlation between the different vegetation parameters and backscatter decreased with increasing frequency. L-band HH-polarization (L-HH) is best suited for the monitoring of fresh weight (r=0.98), dry weight (r=0.96), VWC (r=0.98), and plant height (r=0.96). The correlation coefficients were highest for L-band observations and lowest for X-band. Also, HH-polarization had the highest correlations among the polarization channels (HH, VV and HV). Based on the correlation analysis between backscattering coefficients in each band and wheat growth parameters, we developed prediction equations using the L-HH based on the observed relationships between L-HH and fresh weight, dry weight, VWC and plant height. The results of these analyses will be useful in determining the optimum microwave frequency and polarizations necessary for estimating vegetation parameters in the wheat.

• Food Science and Preservation
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• v.22 no.1
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• pp.84-90
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• 2015

The physicochemical properties and protease activities of spray-dried pineapple juice powders were investigated. The pH, soluble solids, and protease activity of the pineapple juice were pH 5.43, $12.8^{\circ}Brix$, and 4.82 unit/mL, respectively. The optimum pH and temperature of the protease activity from pineapple juice were pH 7.0 and $50^{\circ}C$, respectively. The microencapsulation of pineapple juice was achieved using maltodextrin and alginic acid through spray-drying. The L value and moisture content of the spray-dried powder were higher than those of the freeze-dried powder. The particle size of the freeze-dried powder ($501.57{\mu}m$) was higher than that of the spray-dried powder ($42.58-53.32{\mu}m$). The water absorption and water solubility of the powders were 0.41-0.87, and 90.45-99.76%, respectively. When compared, the protease activities were found to be in the following order : FD (1,297.47 unit/g) > SD-MA-1 (692.08 unit/g) > SD-MA-2 (664.66 unit/g) > SD-MA-3 (642.65 unit/g) > SD-M (633.51 unit/g). In the in vitro dissolution study measurements were conducted for 4 hr in pH 1.2 simulated gastric fluid and pH 6.8 simulated intestinal fluid, using a dissolution tester at $37^{\circ}C$ in 50 rpm. The protease survival of the 3.74-15.69% microencapsulated pineapple juice powders improved with an increase in the treatment concentration of alginic acid.

• Food Engineering Progress
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• v.14 no.4
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• pp.299-306
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• 2010

This study was performed to develop new functional red ginseng drinks with Astragali Radix and Opuntia humifusa. Optimum extraction conditions such as solvent property and temperature for Astragali Radix were determined by distilled water vs. ethanol (95%) ratio (0:100, 25:75, 50:50, 75:25) and 60 vs. $80^{\circ}C$. Water-soluble extracts at $80^{\circ}C$ showed higher antioxidant activities than fat-soluble extracts at $60^{\circ}C$. Viscosities of 1-2% (w/v) of Opuntia humifusa solution were similar to that of the 0.1% guar gum solution. Addtion of Astragali Radix (3% and 5%, w/v) and Opuntia humifusa (1.2%, w/v), especially, had effect on the changes of pH of the red ginseng solution(5%, w/v) during storage for 7 days. A significant difference during the storage was shown in total plate counts by addition of Opuntia humifusa (1.2%, w/v) and microorganisms were reduced by six log cycles. Significant antiproliferation effects of red ginseng (5%, w/v) solution with Astragali Radix (3% & 5%, w/v) and Opuntia humifusa (1.2%, w/v) on Colon26m-3.1 carcinoma (colorectal carcinoma) cell and U87-MG neuronale glioblastoma (brain carcinoma) cell were not observed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47
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• pp.15-32
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• 2002

The endeavors enhancing the grain quality of high-yielding japonica rice were steadily continued during 1980s-1990s along with the self-sufficiency of rice production and the increasing demands of high-quality rices. During this time, considerably great progress and success was obtained in development of high-quality japonica cultivars and quality evaluation techniques including the elucidation of interrelationship between the physicochemical properties of rice grain and the physical or palatability components of cooked rice. In 1990s, some high-quality japonica rice cultivars and special rices adaptable for food processing such as large kernel, chalky endosperm, aromatic and colored rices were developed and its objective preference and utility was also examined by a palatability meter, rapid-visco analyzer and texture analyzer, Recently, new special rices such as extremely low-amylose dull or opaque non-glutinous endosperm mutants were developed. Also, a high-lysine rice variety was developed for higher nutritional utility. The water uptake rate and the maximum water absorption ratio showed significantly negative correlations with the K/Mg ratio and alkali digestion value(ADV) of milled rice. The rice materials showing the higher amount of hot water absorption exhibited the larger volume expansion of cooked rice. The harder rices with lower moisture content revealed the higher rate of water uptake at twenty minutes after soaking and the higher ratio of maximum water uptake under the room temperature condition. These water uptake characteristics were not associated with the protein and amylose contents of milled rice and the palatability of cooked rice. The water/rice ratio (in w/w basis) for optimum cooking was averaged to 1.52 in dry milled rices (12% wet basis) with varietal range from 1.45 to 1.61 and the expansion ratio of milled rice after proper boiling was average to 2.63(in v/v basis). The major physicochemical components of rice grain associated with the palatability of cooked rice were examined using japonica rice materials showing narrow varietal variation in grain size and shape, alkali digestibility, gel consistency, amylose and protein contents, but considerable difference in appearance and texture of cooked rice. The glossiness or gross palatability score of cooked rice were closely associated with the peak, hot paste and consistency viscosities of viscosities with year difference. The high-quality rice variety "IIpumbyeo" showed less portion of amylose on the outer layer of milled rice grain and less and slower change in iodine blue value of extracted paste during twenty minutes of boiling. This highly palatable rice also exhibited very fine net structure in outer layer and fine-spongy and well-swollen shape of gelatinized starch granules in inner layer and core of cooked rice kernel compared with the poor palatable rice through image of scanning electronic microscope. Gross sensory score of cooked rice could be estimated by multiple linear regression formula, deduced from relationship between rice quality components mentioned above and eating quality of cooked rice, with high probability of determination. The $\alpha$-amylose-iodine method was adopted for checking the varietal difference in retrogradation of cooked rice. The rice cultivars revealing the relatively slow retrogradation in aged cooked rice were IIpumbyeo, Chucheongyeo, Sasanishiki, Jinbubyeo and Koshihikari. A Tonsil-type rice, Taebaegbyeo, and a japonica cultivar, Seomjinbyeo, showed the relatively fast deterioration of cooked rice. Generally, the better rice cultivars in eating quality of cooked rice showed less retrogradation and much sponginess in cooled cooked rice. Also, the rice varieties exhibiting less retrogradation in cooled cooked rice revealed higher hot viscosity and lower cool viscosity of rice flour in amylogram. The sponginess of cooled cooked rice was closely associated with magnesium content and volume expansion of cooked rice. The hardness-changed ratio of cooked rice by cooling was negatively correlated with solids amount extracted during boiling and volume expansion of cooked rice. The major physicochemical properties of rice grain closely related to the palatability of cooked rice may be directly or indirectly associated with the retrogradation characteristics of cooked rice. The softer gel consistency and lower amylose content in milled rice revealed the higher ratio of popped rice and larger bulk density of popping. The stronger hardness of rice grain showed relatively higher ratio of popping and the more chalky or less translucent rice exhibited the lower ratio of intact popped brown rice. The potassium and magnesium contents of milled rice were negatively associated with gross score of noodle making mixed with wheat flour in half and the better rice for noodle making revealed relatively less amount of solid extraction during boiling. The more volume expansion of batters for making brown rice bread resulted the better loaf formation and more springiness in rice breed. The higher protein rices produced relatively the more moist white rice bread. The springiness of rice bread was also significantly correlated with high amylose content and hard gel consistency. The completely chalky and large grain rices showed better suitability far fermentation and brewing. The glutinous rice were classified into nine different varietal groups based on various physicochemical and structural characteristics of endosperm. There was some close associations among these grain properties and large varietal difference in suitability to various traditional food processing. Our breeding efforts on improvement of rice quality for high palatability and processing utility or value-adding products in the future should focus on not only continuous enhancement of marketing and eating qualities but also the diversification in morphological, physicochemical and nutritional characteristics of rice grain suitable for processing various value-added rice foods.ice foods.

• Journal of the Korean Wood Science and Technology
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• v.10 no.3
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• pp.118-131
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• 1982

1. In order to investigate the effect of variation of assembly time on glue bond strength, and to determine the optimum range of assembly time with given glue, this experiment was made at the suggestion of the Wood Technology Laboratory, School of Forestry, Yale University. 2. For this investigation, three-ply-plywoods with 1/22 inch, birch veneer, phenolic resin, and soybean glue were made at the following variation of assembly time, that is, 1, 5, 10, 25, 35, 50, and 70 minutes, under both open and closed assembly manners, and the shear strength test at dry and wet were adoptted. 3. The shear strength and wood failure of each plywood panel constructed at the given assembly time have been illustrated in Tables 1, 2, 3 and 4. It has shown that there is a remarkable tendency, for increasing assembly time to give lower shear strength and wood failure throughout almost all cases. The effective range of assembly time of tested glues in this investigation for both open and closed assembly are summarized in the Table 7. Thus, allowable assembly time for Phenolic resin may be up to 10 minutes under open assembly and up to 50 minutes under closed assembly. For soybean glue, the permissible assembly time may be up to 5 minutes under open assembly and up to 15 minutes under closed assembly. The allowable assembly time for open assembly with the same glue is reduced by approximately one third or more than one third as compared with closed assembly time. This might mean that the closed asembly time for these glues is more practical than the open assembly.

• Journal of Food Hygiene and Safety
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• v.22 no.4
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• pp.359-364
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• 2007

This study was conducted to determine the optimum condition of extraction and antioxidant activity of ethanol extracts of Epimedium koreanum Nakai based on the icariin quantity. Also, further organic solvent fractions of hexane, chloroform, ethyl acetate and butanol were obtained from the ethanol extract of Epimedium koreanum Nakai at different temperatures. Total ethanol extraction yield of wild grape seed ranged from 11.8% to 39.3% depending on the concentration of icariin as well as different ethanol concentration, extraction temperature and time condition. Among different extraction temperatures and time, the highest extraction yield of 39.3% was obtained at 70% ethanol for 3 hour at $50^{\circ}C$ in the sample containing the 0.596% icariin (KE9412). In the meantime, the strongest free radical scavenging effect $(RC_{50})$ with $18.9{\mu}g/mL$ in the KE9412 sample was observed in 70% ethanol extract of Epimedium koreanum Nakai extracted for 7 hour at $70^{\circ}C$, while $RC_{50}$ with $35.2{\mu}g/mL$ was observed in the KE9405 (0.20% icariin content) sample at same condition. Also, antioxidant activity of ethanol extracts of Epimedium koreanum Nakai increased as icariin concentration increased. Among each fraction obtained from organic solvents, butanol fraction was found to have the strongest $RC_{50}\;(39.2{\mu}g/mL)$ and followed by ethylacetate $(49.0{\mu}g/mL)$, water $(118.8{\mu}g/mL)$, ethylacetate $(119.8{\mu}g/mL)$, and chloroform fraction $(138.5{\mu}g/mL)$ respectively.

• The Korean Journal of Malacology
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• v.30 no.3
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• pp.219-226
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• 2014

The effects of different stocking densities on the growth and survival rate of the abalone, Haliotis discus hannai, were investigated in marine net cage for two years. Stocking density was set 15, 30, 45 and 60 percentage $(=per.)/m^2$ with share to cross-sectional area per shelter. The primary rearing period (PRP) and the secondary rearing period (SRP) were conducted by a year. One year mean water temperature of PRP and SRS showed the difference about $2^{\circ}C$. In the growth (initial mean shell length of abalone : $36.14{\pm}2.28mm$) of PRP, the absolute growth rate (ARG), daily growth rate (DGR) and specific growth rate (SGR) of the $15per./m^2$ were higher than those of density groups (P < 0.05). Survival rates of all density groups were showed no significant difference. In the growth (mean shell length of abalone : $55.26{\pm}6.93mm$) of SRP, ARG, DGR and SGR of stocking density groups showed no significant difference except for $45per./m^2$ density group. Survival rate in the low-density (15, $30per./m^2$) was more than 70%, and those of the high-density (45, $60per./m^2$) were less than 31% and 9%, respectively. These results showed that the appropriate stocking density for $15per./m^2$ was seven hundred fifty number per one net cage ($2.4{\times}2.4m$), during PRP using 3-4 cm abalone in length. Also for the secondary rearing period, the optimal stocking density (shell length 5-6 cm of abalone) consider with the economical efficiency was determined to be $30per./m^2$, resulting the productivity improved.