• Journal of Bio-Environment Control
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• v.22 no.3
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• pp.248-255
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• 2013

This study examined an automated irrigation technique by a frequency domain reflectometry (FDR) sensor for scheduling irrigation for tomato (Solanum lycopersicum L. 'Starbuck F1') cultivation aimed at avoiding effluent from an open hydroponic system with coir substrate containing different ratios of chip-to-dust (v/v) content. Specifically, the objectives were to undertake preliminary measurements of irrigation volumes, leachate volume, volumetric water content and electrical conductivity (EC) in the substrate, plant growth, fruit yield, and water use efficiency resulting from variation in chip content as an initial experiment. Commercial coir substrates containing different percentages of chips and dust (0 and 100%, 30 and 70%, 50 and 50%, or 70 and 30%), two-story coir substrates with different percentages of chips in the lower layer and dust in the upper layer (15 and 85%, 25 and 75%, or 35 and 65%), or rockwool slabs were used. The results showed that a negligible or no leachate was found for all treatments when plants were grown under a technique for scheduling non-drainage irrigation using a frequency domain reflectometry (FDR) sensor. Daily irrigation volume was affected by chip content in both commercial and two-story slabs. The highest plant growth, marketable fruit weight, and water-use efficiency were observed in the plants grown in the commercial coir slab containing 0% chips and 100% dust, indicating that the FDR sensor-auto-mated irrigation may be more useful for tomato cultivation in coir substrate containing 0% chips and 100% dust using water efficiently and minimizing or avoiding leachate and thus increasing yield and reducing pollution. Detailed experiment is necessary to closely focus on determining appropriate irrigation volume at each of irrigation as well as duration of each individual irrigation cycle depending on different physical properties of substrates using an automated irrigation system operated by the FDR sensor.

• Journal of the Korea Organic Resources Recycling Association
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• v.15 no.4
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• pp.115-124
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• 2007

The material compressions in the vertical composting reactor affect to the biodegradation rates of the organic wastes. This study investigated the variations of physical properties of the composting materials according to the height of reactor due to affect to the settlement in the vertical composting reactor. The variations of decreased temperature after peak temperature showed the different patterns depending on the reactor heights. The variation width of re-increased temperature after peak temperature was reduced as the mixing operations were increased, and increased as the height of reactor elevated. The moisture content and the variation width of the moisture content were increased higher as the height of the reactor became higher. The variations of the bulk density at each height of vertical reactor showed the same tendency comparing with those of the moisture content. The relationship between bulk density and moisture content had shown the quadratic equation (r2=0.94). The dry solid contents at each reactor height were decreased as the height of reactor were increased. The results of the variation of the physical properties during the composting process were caused by the downward compression of the material into the reactor. Settlement rate in the vertical composting reactor was estimated about 2.184cm/day. To increase the biodegradation efficiency in the vertical reactor, the conditions of air path in the composting material matrix have to be investigated afterwards.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.4
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• pp.437-442
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• 1993

Soybean curds were made from the mixture of soybean milk and cow's milk (raw milk) at the ratio of 10, 20, 30, 40, 50% (v/v), and then the general composition and mineral content, pH, yield, firmness by sensory evaluation and amino acid composition were investigated. As cow's milk addition increased, total sugar crude fat, crude protein, ash content, firmness, weight and volume of the soybean curd were increased. Whereas moisture content decreased, $Ca^{＋＋}$, $K^{＋}$, and Na$^{＋}$ were increased, but $Mg^{＋＋}$ and Fe$^{＋＋}$ decreased. In sensory evaluation, color (white), firmness, flavor, and taste were higher than those of control as cow's milk increased. By adding cow's milk at the ratio of 10, 20, 30, 40%, and 50%, sulfur containing amino acid content such as methionine and cystine were enriched 1.31, 1.58, 1.67, 1.85, and 1.95 times, respectively.

• Korean Journal of Food Science and Technology
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• v.16 no.1
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• pp.37-40
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• 1984

A simple and low cost autogenous-type extruder with a capacity of about 400kg/hr for rice bran-oil stabilization was developed. Specific energy consumption of the extruder was 0.060-0.070 KWH/kg of rice bran during extrusion. Rice bran was easily extruded to form flakes or pellets with an increase of bulk density. And also the desired extrusion temperature of $95^{\circ}C{\;}to{\;}150^{\circ}C$ could be easily obtained without any water addition when the rice bran was properly parametered with feed rate. The moisture content of bran was reduced and peroxidase was significantly inactivated after extrusion. The rice bran stabilized by the extrusion process was excellent in storage stability without considerable increase in free fatty acids.

• Journal of Animal Environmental Science
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• v.14 no.3
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• pp.193-200
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• 2008

The results of the research on the amount of water evaporation from composting facilities operated in swine farms are below. The number of swine per a farm was 1433 head/farm for a Simple Composting Facility (SCF) and 3500 head/farm for a Escalator composting facility(ECF) system. The capacities of the SCF and the ECF were $0.33m^3/head$ and $0.25m^3/head$, respectively. The ECF had 24.2% less capacity than the SCF. The average water contents in the swine manure for the CP and the ECF of the surveyed farms were 86.8% and 85.7%, respectively, which revealed the ECF had 1.3% less average water content than the SCF. Daily water inputs into the SCF and the ECF were $4.1kg/m^3/day$ and $6.5kg/m^3/day$, respectively. The ECF had approximately 36.9% higher water input than the SCF. Fermentation temperatures during the composting period for the SCF and the ECF were up to $45^{\circ}C$ and $70^{\circ}C$, respectively. The decreases in water contents per each square meter for the SCF and the ECF were 3.7 kg and 5.2 kg, respectively. The ECF lost approximately 28.8% more water content than the ECF, which would be caused by the difference of fermentation temperature between two systems. Fertilizer components after composting were examined. Nitrogen contents of the SCF and the ECF were similar (0.84% and 0.86%, respectively) and ${P_2}{O_5}$ contents were 0.78% and 0.74%, respectively, showing the SCF had slightly higher content than the ECF. However, OM and OM/N did not show the difference between two systems. Hence, efforts to increase composting efficiency with considerations of the water content of swine manure, fermentation temperature, and water evaporation potential should be done when the SCF and the ECF were used in swine farms.

• Journal of Bio-Environment Control
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• v.24 no.3
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• pp.153-160
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• 2015

The objectives of this study were to determine optimal length of off-time between irrigation cycles to improve irrigation efficiency using a frequency domain reflectometry (FDR) sensor-automated irrigation (FAI) system for tomato (Solanum lycopersicum L.) cultivation aimed at minimizing effluent from coir substrate hydroponics. For treatments, the 5-minute off-time length between 3-minute run-times (defined as 3R5F), 10-minute off-time length between 3-minute run-times (defined as 3R10F), or 15-minute off-time length between 5-minute run-times (defined as 5R15F) were set. During the 3-minute or 5-minute run-time, a 60mL or 80mL of nutrient solution was irrigated to each plant, respectively. Until 62 days after transplant (DAT) during the autumn to winter cultivation, daily irrigation volume was in the order of 3R5F (858mL) > 5R15F (409mL) > 3R10F (306mL) treatment, and daily drainage ratio was in the order of 3R5F (44%) > 5R15F (23%) > 3R10F (14%). Between 63 and 102 DAT, daily irrigated volume was in the order of 5R15F (888mL) > 3R5F (695mL) > 3R10F (524mL) with the highest drainage ratio, 19% (${\pm}2.6$), at the 5R15F treatment. During the spring to summer cultivation, daily irrigation volume and drainage ratio per plant was higher in the 3R5F treatment than that of the 3R10F treatment. For both cultivations, a higher water use efficiency (WUE) was observed under the 3R10F treatment. Integrated all the data suggest that the optimal off-time length is 10 minutes.