• Clean Technology
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• v.19 no.4
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• pp.464-468
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• 2013

In this study, in order to increase solid content of coal water fuel (CWF), various experimental parameters (i.e., coal type, additive, particle size distribution, drying method) were evaluated. To investigate the drying method, specimen is compared to using flash dry, fluidized bed dry and oil deposit stabilized coal. Difference of the solid content between low rank coal and high rank coal in this case indicate that high rank coal exhibits more higher than 20% of the solid cotent. And specimen for dispersibility was prepared by using dispersing agent of 4 types. As a result, using the dispersing agent was shown 5% higher in sold content than the case of not using the dispersing agent. Efficiency of CWF was improved by using fine coal of 80% in the particle size distribution of coal. Result of CWF using drying methods of 3 types, oil deposit stabilized (ODS) coal dried and stabilized was effective 12% higher in sold content than raw coal.

• Journal of the Korean Wood Science and Technology
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• v.37 no.3
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• pp.192-199
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• 2009

This study was carried out to investigate the performance of a radio-frequency/vacuum dryer combined with a mechanical compressive load (RF/VC) with a scale of about $3m^3$ during drying board of Azobe (Lophira alata) and Korean red pine (Pinus densiflora). The degree of vacuum of the RF/VC system was maintained at 80~105 torr, and wood temperature was increased from $40^{\circ}C$ at the beginning of drying to $60^{\circ}C$ at the end of drying and the radiofrequency generator was operated with schedule of 7 minute-ON and 3 minute-OFF. The wood temperatures near charge plate always remained higher than those of the control during all of the drying stage, whereas the wood temperature near ground plate always remained lower than those of the controlled. As drying time proceeding, the temperature of the wood near ground plate presented lower than those of the control. Whereas the temperature of the wood near charge plate presented higher than those of the controlled. The final average moisture contents of the Azobe boards stacked near the input side of the RF generator showed slightly lower than those near the opposite side. Those of the wood stacked in the layers near the charge plate were lower than those of near the ground plate. The average length of surface checks of the Azobe boards stacked near the charge plate was very slight, whereas that toward the ground plate represented high values. The efficiency of input energy was simliar with the commercial systems.

• Korean Journal of Food Science and Technology
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• v.21 no.5
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• pp.676-685
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• 1989

Optimal operating conditions of on-farm red pepper dryer were searched by using the simulation-optimization algorithm combining the drying and quality deterioration models of red pepper with Box's complex method. Determination of control variables such as air temperature, air recycle ratio and air flow rate was based on a criterion of minimizing energy consumption under the constrainst conditions that satisfied the specified color retention of carotenoids. As quality constraint was stricter, energy consumption increased and total drying time decreased with lower recycle ratio and higher air flow rate Product mixing during drying was found to be able to improve the energy efficiency and product quality. Currently used air flow rate was assessed to be increased for the optimal operation. Two stage drying at the fixed optimal air flow rate was proven to be useful means for further saying of energy consumption. In the optimal bistaged drying, the second stage began at about one third of the total drying time and low air temperature in the first stage Increased to a high value and air recycle ratio increased slightly in the second stage. Optimal control variable scheme could be explained by the dryer performance and the carotenoids destruction kinetics in red pepper drying.

• Applied Biological Chemistry
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• v.26 no.2
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• pp.75-81
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• 1983

The performance of the flat-plate solar collector with rock-pile thermal storage medium and the drying characteristics of rough rice and red pepper by use of natural air and of supplementary heated air by the solar drier were studied. The thermal efficiency of the flat-plate solar collector was average 25.4 percent and the overall heattransfer coefficient of the collector was approximately $38.13kJ/hr.m^2^{\circ}C$. The flat-plate collector was able to supply the supplementary heated air which was about $7^{\circ}C$ higher than the ambient air temperature during the daytime and about $3^{\circ}C$ higher than during the night. For rough rice drying of grain moisture content front 24.5 to 14.5%, it took 18 days in the natural air system, 12 days in the tubular solar collector and 10 days in the flat-plate solar collector. For red pepper drying from it's moisture from 81.0 to 15.0%, 68 hrs required under conventional sun drying system, but 38 hrs in tubular solar collector and 36 hrs in the flateplate solar collector. The changes of capsanthin and capsaicine content were investigated at various drying system, and little difference was found among the drying system.

• Korean Journal of Food Science and Technology
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• v.51 no.5
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• pp.447-451
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• 2019

6-gingerol can be converted to 6-shogaol, one of the predominant active compounds found in ginger, via processing such as drying and extraction. Subcritical water extraction is the environmentally friendly method of extraction of bioactive compounds using only purified water as a solvent. This study investigated subcritical water extraction ($190^{\circ}C$, 15 min) of 6-gingerol, and 6-shogaol from dried ginger (Zingiber officinale) including drying conditions such as temperature (room temperature, 60, $80^{\circ}C$, and freeze drying) and time duration for drying (1-4 h). The amount of 6-gingerol was found to be reduced, and that of 6-shogaol was found to be increased depending upon the water content of dried ginger. Upon oven-drying ginger at $60^{\circ}C$ for 2 h, the maximum yields of 6-gingerol ($0.18{\pm}0.02mg/g$ fresh weight), and 6-shogaol ($0.47{\pm}0.02mg/g$ fresh weight) were obtained upon subcritical water extraction.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.2
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• pp.91-100
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• 2004

This study was on a recyling system of food waste using poultry and earthworms. Food waste was fed to the egg-raising hens(Gallus gallus) or ducks(Anas platyrynchos). And the excrement of poultry after ingestion of food waste was mixed with other organic waste such as paper mill sludge or night soil sludge, aged and then provided to the earthworms(Eisenia andrei). An egg-raising hen and a duck ate up 0.40kg and 0.79kg of food waste per day, respectively. And the percental rate of exctretion(the amount of excrement/the amount of food waste eaten up) of an egg-raising hen and a duck was 71.0% and 53.7%, respectively. The excrement of poultry that had been mixed with paper mill sludge and aged was vermicomposted more easily than the excrement that had been mixed with night soil sludge and aged. The excrement of poultry aged for more than 21 days was more suitable to vermicompost than the excrement of poultry aged for less than 21 days. Even though, the earthworm lost its biomass on the mixed feeds regardless of their aging periods, which was supposed to be caused by high salinity in poulty's excrements.

• Journal of Sericultural and Entomological Science
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• v.52 no.1
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• pp.73-78
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• 2014

This study was carried out to establish the self-specification and shelf-life by standardization of manufacturing process for Tenebrio molitor larvae. First, standardization of manufacturing process for T. molitor was set up. Sterilization for larvae placed on a multistage shelf with intervals of about 10 cm was carried out at $115^{\circ}C$, $1kgf/cm^2$ for 10 min. After sterilization, T. molitor larvae were frozen at less than $-35^{\circ}C$ for more than 12 hrs. And then, they were dried under $-15^{\circ}C$, 0.5 torr vacuum for more than 30 hrs. Second, we decided self-specification for T. molitor larvae. Their moisture, acidity, peroxide, crude protein and crude fat level should be 5% or less, 3 mg/g or less, 30 meq/g or less, 45% or more, and 25% or more, respectively. Also, oleic acid, representative material, level was set up 11 ~ 16%. Third, we decided shelf-life by analysis of the physicochemical characteristic, sensory evaluation and microbial indicators. The final expiry date for lyophilized T. molitor larvae in PET bottle was calculated as 12 months from date of manufacture. We expect that optimal manufacturing process system, self-specification, and shelf-life proposed in this study can be used in industrial production of T. molitor as a novel food.

• Proceedings of the KAIS Fall Conference
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• 2007.11a
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• pp.386-389
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• 2007

본 논문은 $TiO_2$(Degussa, P-25), 바인더(A-9540) 그리고 용제의 배합비율을 바꾸어 코팅액을 제조하여 금속판에 코팅한 후, 고농도의 IPA를 주입하여 분해효율을 고찰하였다. 고형분 함량 비율 변화에서는 $TiO_2$ 함량은 증가하고 바인더가 감소할수록 좋은 효율을 보였고, 용제는 ethanol과 MEK 두 가지 중에 MEK의 분해효율이 좋았다. 용제(MEK)함량 비율 변화에서는 일정량의 용제가 있을 경우 분해효율이 좋았고, 용제함량이 낮아질 경우 코팅액 점도가 높아지고 건조 후에는 표면이 갈라지는 현상을 보였다. 결국, 용제함량 비율 변화는 바인더 함량 실험에도 영향을 주어 1.75:0.25:10일 때 가장 좋은 분해효율을 보였다.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.7
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• pp.694-699
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• 2008

Considering the severe regulation associated with sludge treatment such as direct landfill and ocean dumping, there is no doubt in that an advanced study for the proper treatment of sludge is urgently needed in near feature. As one of viable method for sludge treatment, fry-drying of sludge by waste oil has been investigated in this study. The fundamental mechanism of this drying method lies in the phenomenon of rapid moisture escape in the sludge pore toward oil media. This is caused by the severe pressure gradient formed by the rapid oil heating between sludge and oil. As part of research effort of fry-drying using waste oil, a series of basic study has been made experimentally to obtain typical drying curves as function of important parameters such as drying temperature, drying time, oil type and geometrical shape of sludge formed. Based on this study, a number of useful conclusion can be drawn as following. The fry-drying method by oil immersion was found quite effective in the removal efficiency of sludge moisture, in general, the moisture content decreases significantly after 10 minutes and the whole moisture content was less than 5% after 14 minutes regardless of the drying temperature. The increase of oil temperature up to 140$^{\circ}C$ favors significantly for the removal of moisture but there was no visible difference above 140$^{\circ}C$. As expected, the decrease of diameter in sludge was efficient in drying due to the increased surface area per unit volume. Further, the effect of oil property by the change of oil type was noted. To be specific, for the case of engine oil the efficiency was found to be remarkably delayed in moisture evaporation compared with that of vegetable oil due to the increased viscosity of engine oil. It produced a result of increasing the evaporation of moisture largely relatively high in the drying temperature over 140$^{\circ}C$ compared with the drying temperature 120$^{\circ}C$ drying temperature as the drying time passed. Accordingly, the drying temperature is considered desirable as keeping over 140$^{\circ}C$ regardless of a sort of used oil.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.6
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• pp.406-410
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• 2005

This study was conducted to establish the efficient protocols of the germination and cryopreservation of dehisced Korean ginseng seeds for long-term germ­plasm conservation. $GA_3$ and BA treated on seed for 24 hr facilitated germination at 5 and $10^{\circ}C$. Germination percentage of desiccated seeds was decreased under moisture content (MC) of below $7.2\%$. Dehisced ginseng seeds were dried under airflow of laminar floor cabinet and seed drying room. The high levels (more than $90\%$) of germination after cryogenic exposure were obtained after drying under vertical airflow of laminar floor for 12-30 hours (MC $10.6{\~}7.2\%$). Decrease in germination percentage of ginseng seeds due to desiccation damage and freezing injury was observed at MC of below $7.2\%$ and of above $12.1\%$, respectively. Therefore, MC of ginseng seeds need to be controlled with a range of $8{\~}10\%$ to avoid damages from both desiccation and freezing.