• Resources Recycling
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• v.15 no.3 s.71
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• pp.38-45
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• 2006

The thermal filter press dewatering(TFPD) technology to improve the dewaterability through increasing the inner vapor pressure, lowering the filtration viscosity and forming the porosity easily within cake as applying the heat at the sludge layer was developed in this study. The hot water with temperature of $95^{\circ}C$ and pressure of $1.2kg_f/cm^2$ was supplied to the heating plate equipped between filter plates with plate size of $470{\times}470mm$ and material of polypropylene. Sludge was dewaterd by supplying pressure of $5kg_f/cm^2$ and then by squeezing pressure of $15kg_f/cm^2$. As a results of estimating the characteristics of thermal dewatering to consider the initial water content and organic content to be influenced by a period of water shortage and rainwater, the dewatered cake water content was about 35 wt% and dewatering velocity was $4DSkg/m^2{\cdot}hr$ under the rainwater period, and the dewatered cake water content was about 50 wt% and dewatering velocity was $1.5DSkg/m^2{\cdot}hr$ in the case of sludge of water shortage season. These results was superior to the mechanical dewatering performance with water content of 70wt% and dewatering velocity of $0.9DSkg/m^2{\cdot}hr$. On the base of the results of TFPD, energy consumpted to deal with DS(Dry Solid) of 1kg was estimated by 300 kJ. It was analyzed that the energy consumption of TFPD was decreased about one third with comparison to the dryer system. Dewatering velocity of this technology was faster than the one of mechanical dewatering equipment and it was easier to product low water content cake. Therefore, this technology was recognized that dewaterability was predominant because of the fast of dewatering velocity and production of low water content cake, and also this known as economical efficiency was excellent because of low energy consumption in comparison with dryer.

• Culinary science and hospitality research
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• v.20 no.6
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• pp.235-244
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• 2014

The purpose of this study was to investigate the effect of freezing and thawing rate on the physical properties of soybean sprouts to improve the quality of processed soybean sprouts during distribution and storage. Cooked soybean sprouts were frozen by air-blast freezing (ABF) system at $-45^{\circ}C$ or natural air convection freezing (NCF) system at $-24^{\circ}C$, then thawed using microwave oven by varying output power (0, 400, 800 and 1,000 W) until $75^{\circ}C$. The quality of soybean sprouts was measured by the water content, hardness and springiness. In addition, the internal microstructure of soybean sprouts was observed by optical microscope. For results, water content of soybean sprouts thawed by 1,000 W in a microwave showed the lowest value after natural air convection freezing. Springiness of soybean sprouts thawed by all amounts of output power was decreased in comparison with control. Hardness was increased only in soybean sprouts thawed by 1,000 W after air-blast freezing. However the gaps between springiness and hardness were relatively small with control at 1,000 W thawing, after air-blast freezing. Internal microstructure of the soybean sprouts was more damaged as freezing and thawing time were increased. In conclusion, high freezing and thawing rate might improves the quality of soy bean sprout, and IQF freezing and 1,000 W of microwave thawing appears to be the optimum condition for frozen HMR production. From the results freezing and thawing process parameters might can be use as quality control parameters as various type of sprout products processing.

• Journal of Korean Society of Forest Science
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• v.14 no.1
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• pp.21-31
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• 1972

It has intended to identify the members of the Genus Lespedeza in Korea by a chemical colour reaction, and the following five species of the Genus Lespedeza grown in the garden have been used in this experiment. 1. Lespedeza bicolor Turcz 2. Lespedeza bicolor var. melanantha (Nak.) T. Lee 3. Lespedeza cyrtobotrya Miq. 4. Lespedeza japonica var. intermedia Nakai 5. Lespedeza maritima Nakai 6. Lespedeza maximowiczii Schneider 7. Lespedeza maximowiczii var. tomentella Nakai A few drops of each solution of $K_2Cr_2O_7$. $FeSO_4{\cdot}7H_2O$, $FeCl_3$, $KH_2PO_4$, $KMnO_4$, $NH_4OH$, and HCl was added to the methanol extracts of wood dust to get the specific colour reaction. HCl-infused wood was also used for the identification of L. bicolor var. melanantha and L. bicolor. The results can be summarized as the following key; 1. Chrome lemon by $K_2Cr_2O_7$ ${\cdots}{\cdots}$2 1. Sun flower yellow by $K_2Cr_2O_7$ ${\cdots}{\cdots}$Lespedeza maximowiczii var. tomentella Nakai 2. $KH_2PO_4$ Oystem white by $KH_2PO_4$; golden yellow by $FeCl_3$ ${\cdots}{\cdots}$=3 2. Cream colour by $KH_2PO_4$=6 3. Oyster white by $NH_4OH$; corn colour by $FeSO_4{\cdot}7H_2O$ ${\cdots}{\cdots}$4 3. Cream colcur by $NH_4OH$ ${\cdots}{\cdots}$5 4. Van dyke brown by $KMnO_4$ ${\cdots}{\cdots}$; sea shell pink by HCl injection under heating ${\cdots}{\cdots}$Lespedeza japonica var. intermedia Nakai 4. Sepia colour by $KMnO_4$; honey colour by HCl injection under heating ${\cdots}{\cdots}$Lespedeza maritima Nakai 5. Golden red by $FeSO_4{\cdot}7H_2O$; andover green by HCl-infused wood dust ${\cdots}{\cdots}$Lespedeza bicolor var. melanantha (Nak.) T. Lee 5. Yellow ochre by $FeSO_4{\cdot}7H_2O$; sand warm gray by HCl-infused wood dust ${\cdots}{\cdots}$Lespedeza bicolor Turcz 6. Amber green by $FeCl_3$ ${\cdots}{\cdots}$Lespedeza cyrtobotrya Miq. 6. Leather brown by $FeCl_3$ ${\cdots}{\cdots}$Lespedeza maximowiczii Schneider.

• Journal of agriculture & life science
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• v.53 no.5
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• pp.137-143
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• 2019

To manufacturing of solid fuel by reuse of the wastes, the drying unit which have 500 kg/hr of drying capacity was developed and experimentally evaluate the performance. The spinach grown in Nam-hae island were used for the experiments and investigated of the heated-air drying characteristics as the inlet amount of raw materials, raw material stirring status, conveying type and drying time. The drying air heated by the energy derived from the steam which is supplied from the incineration plant. The moisture contents of raw materials were measured 85.65%. The inlet flow rate of drying air made a difference as the depth of the raw materials loaded on the drying unit and temperature has showed 108~144℃. The drying speed of the mixed drying more than doubled as that of non mixed drying under the same drying type, inlet amount, drying time and drying air temperature. In each experiment, the drying capacity have showed over 500 kg/hr. A drying efficiency of the ratio of drying consumption energy to input energy was 33.46%, lower than the average of 57.76% for the 157 conventional dryers. Because developed dryer must have a drying time of less than one hour, it is considered that the dry efficiency has been reduced due to the loss of wind volume during drying. If waste heat from incineration plant is used as a direct heat source, the dry air temperature is expected to be at least 160℃, greatly improving the drying capacity.

• Resources Recycling
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• v.23 no.1
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• pp.58-63
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• 2014

Variety of volatile materials is present in crude-Zinc oxide recovered from EAFD(Electric arc furnace steel dust). Commonly, it is purified by oxidizing roasting. In this study, spherical each specimen prepared crude-zinc oxide like 1~3 mm and 10 mm was tested in vertical tube furnace at the temperature range $600^{\circ}C$ to $1200^{\circ}C$ in oxidizing atmosphere. Oxidizing roasting properties of zinc oxide were investigated using XRD, XRF and ICP-OES. At temperature blow $950^{\circ}C$ volatilization rate were remarkably low. As the temperature increases, the concentration of Zn increased and the concentration and XRD peaks of impurities decreased. The result indicated that volatilization rate depended on specimen size and roasting temperature.

• Journal of Energy Engineering
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• v.17 no.1
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• pp.8-14
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• 2008

The effects of calcium type catalysts addition on the thermal decomposition of low density polyethylene (LDPE) and ethylene vinyl acetate (EVA) resin have been studied in a thermal analyze. (TGA, DSC) and a small batch reactor. The calcium type catalysts tested were calcinated dolomite, lime, and calcinated oyster shell. As the results of TGA experiments, pyrolysis starting temperature for LDPE varied in the range of $330{\sim}360^{\circ}C$ according to heating rate, but EVA resin had the 1st pyrolysis temperature range of $300{\sim}400^{\circ}C$ and the 2nd pyrolysis temperature range of $425{\sim}525^{\circ}C$. The calcinated dolomite enhanced the pyrolysis rate in LDPE pyrolysis reaction, while the calcium type catalysts reduced the pyrolysis rate in EVA pyrolysis reaction. In the DSC experiments, addition of calcium type catalysts reduced the melting point, but did not affect to the heat of fusin. Calcinated dolomite reduced 20% of the heat of pyrolysis reaction. In the batch system experiments, the mixing of calcinated dolomite and lime enhanced the yield of fuel oil, but did not affect to the distribution of carbon numbers.

• Korean Journal of Food Science and Technology
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• v.29 no.1
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• pp.32-37
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• 1997

The rate constants and activation energies for formation of two chemical markers, M-1 and M-2 at sterilization temperatures were determined in a meatball system. Destruction rates for bacterial spores were also determined. The rate constants for M-1 and M-2 formation at $121^{\circ}C$ were 0.03 and 0.28 Abs/min, respectively. The activation energies for M-1 and M-2 were 27.9 and 24.6 Cal/mol. M-2 was formed faster than M-1 and reached a maximum and decreased. M-1 formation continued up to 30 min at $121^{\circ}C$ and 10 min at $131^{\circ}C$, which makes M-1 a more useful chemical marker for high $F_0$ values. The D-values for spores (B. stearothermophilus ATCC 12980) at 111, 114.4, 117.7 and $121^{\circ}C$ were 7.5, 4.5, 1.9 and 0.58 respectively. At temperatures between 111 and $121^{\circ}C$, there was a liner correlation between destruction of the spores and the M-1 formation. It was difficult to get accurate D-value at $126^{\circ}C\;and\;131^{\circ}C$, because almost all spores were dead before temperature at the center of the meatball reached $126^{\circ}C$. These data suggest that the chemical marker should be used to evaluate overprocessing as well as microbial lethality in aseptic processing.

• Korean Journal of Food Science and Technology
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• v.26 no.6
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• pp.814-818
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• 1994

Control system for both rapid fermentation and storage of yogurt in refrigerator was developed and its performance was investigated. Fermentation temperature for normal and Bifidus containing yogurt was maintained at maximum $40^{\circ}C$ for about 7 and 11 hours, respectively. The pH, acidity, total viable cell number of lactic acid bacteria and viscosity of both yogurts after completing the fermentation were $4.23{\sim}4.29$, $0.93{\sim}0.97%$, $4.8{\times}10^7{\sim}$2.54{\times}10^8\;cfu/ml$ and $1,700{\sim}1,810\;cp$, respectively. The rate of fermentation for normal yogurt was faster than that of Bifidus yogurt. The changes of pH, acidity, viable cell number and viscosity during storage time were $4.09{\sim}4.54$, $0.76{\sim}1.1%$, $9.4{\times}10^6{\sim}5.68{\times}10^8\;cfu/ml$ and $1,450{\sim}2,000\;cp$, respectively. Yeast and fungi were not nearly detected during storage time for both yogurts.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.1
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• pp.54-60
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• 2006

[ $MnO_2$ ]-Coated Sand(MCS) was prepared with variation of coating temperature, coating time, and dosage of initial Fe(III) with two kinds of sands such as Joomoonjin and quartz sand. An optimum condition for the preparation MCS was determined from the coating efficiency as well as the oxidation efficiency of As(III). Coating efficiency of Mn was strongly dependent on the coating temperature but quite similar over the investigated coating time, showing an increased coating efficiency at higher coating temperature. In contrast to coating efficiency, the oxidation efficiency of As(III) by MCS was severely reduced as increase of coaling temperature. By considering these results, an optimum coating temperature and time for the preparation of MCS was selected as $150^{\circ}C$ and 1-hr, respectively. Coating efficiency increased as the dosage of initial Mn(II) increased, while As(III) oxidation was maximum at 0.8 Mn(II) mol/kg sand. The solution pH was identified as an important parameter affecting stability of MCS, and dissolution of Mn from MCS increased as pH decreased. Oxidation rate of As(III) increased as the dosage of MCS increased as well as solution pH decreased.

• Applied Chemistry for Engineering
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• v.8 no.1
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• pp.99-107
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• 1997

This study Provides the treatment methods of liquid wastes from the dissolution/purification process of nuclear fuel raw material and the fabrication process of nuclear fuel powder. One of the treatment methods is to process liquid waste from uranium raw material dissolution/purification process. This waste, of the strong acid, can be reused to dissolve the fine ADU particles in filtrate which is ADU waste of pH 8.0 converted from AUC waste after recovery of uranium. To dissolve the fine ADU particles, ADU filtrate was pretreated to pH 4.0 with the dissolution/purification waste, and then mixed with the lime to pH 9.2 and aged for 30 minutes. From this processing, uranium content of the filtrate was decreased to below 3ppm. The waste from fuel powder fabrication is emulsified solution dispersed with fine oil droplets. This emulsion was destroyed effectively by adding and mixing the nitric acid with rapid heating at the same time. After this processing, $Na_2U_2O_7$ compound is produced by addition of NaOH. Optimum condition of this processing was shown at pH 11.5, and uranium content of the filtrate was analyzed to 5ppm. To remove the trace of uranium in the filtrate, lime should be added. Otherwise, 4N nitric acid was used to destroy the emulsion directly, and then lime was added to this waste. Uranium content of the treated filtrate was below 1 ppm. In addition to these wastes, the trace of uranium in filtrate after recovery of uranium from the AUC waste which is produced during PWR power preparation, is treated with NaOH to takeup fluorine(F) in the waste because fluorine is valuable and toxic material. In the finally treated waste, uranium was not detected.