• Title/Summary/Keyword: Heat extraction rate

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A study on recovery of rare earth oxide powders from waste NiMH batteries (폐니켈수소전지로부터 희토류 산화물 분말의 회수에 대한 연구)

  • Ahn, Nak-Kyoon;Kim, Dae-Weon;Shim, Hyun-Woo;Park, Jae-Hun;Park, Jeung-Jin
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.28 no.2
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    • pp.85-90
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    • 2018
  • For the recovering rare earths in the spent nickel-metal hydride batteries, 10 M NaOH is added to the solution leached with sulfuric acid. The rare earth powders were precipitated at rate of 98 % at the condition of pH 2.0 or less. The recovered rare earth complex precipitate increased the leaching rate to nitric acid by heat treatment at $800^{\circ}C$ for 4 hours. Subsequently secondary precipitation was performed by adding oxalic acid to the solution in which the rare earth complex precipitate was dissolved. The re-precipitated rare earth powders were converted into oxide form through heat treatment at $800^{\circ}C$ for 4 hours with purity of 99.5 %.

Evaluation of Chemical Pre-treatment for the Optimization of CO2 Fixatiom Using by Carbonation Reaction with Serpentine (이산화탄소 광물고정화 효율 증가를 위한 사문석의 화학적 전처리에 관한 연구)

  • Jang, Na Hyung;Shim, Hyun Min;Hua, Xu Li;Kim, Hyung Teak
    • Applied Chemistry for Engineering
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    • v.19 no.5
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    • pp.526-532
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    • 2008
  • The proposed $CO_2$ storage technology in the present study is a one-step sequestration process that stabilizes $CO_2$ in a reactor with Serpentine. The advantage of this technology is associated with its high stability of final product so that the entire system is recognized as permanent environment-friendly $CO_2$ removal method. Since the sequestration reaction mechanisms are generally understood that carbonation reaction proceeds with very slow rate, so that pretreatment method to increases reaction rate of $CO_2$ carbonation reaction should be developed. To increase the reactivity of Serpentine with $CO_2$, two different methods of pretreatment are carried out in the present investigation. One is heat-treatment, the other is chemical pretreatment. In this study, only chemical pretreatment is considered leaching method of magnesium from Serpentine using sulfuric acid at the various reaction temperatures, times, and acid concentrations. Experimental results illustrated that pretreatment by sulfuric acid increases surface area of serpentine from $11.1209m^2/g$ to $98.7903m^2/g$ and extracts magnesium compounds. Single variable experiment demonstrated the enhancements of magnesium extraction with increased reaction temperature and time. Amount of magnesium extraction is obtained by using the data of ICP-AES as maximum extraction condition of magnesium is 2 M acid solution, $75^{\circ}C$ and 1hr. After performing chemical pretreatment, carbonation yield increased from 23.24% to 46.30% of weight.

Separation of Phosvitin from Egg Yolk without Using Organic Solvents

  • Jung, Samooel;Ahn, Dong Uk;Nam, Ki Chang;Kim, Hyun Joo;Jo, Cheorun
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.11
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    • pp.1622-1629
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    • 2013
  • The objective of this study was to develop a new method to separate phosvitin from egg yolk without using organic solvents. Phosvitin was extracted from yolk granules using 10% NaCl or 10% $(NH_4)_2SO_4$ (final concentration) and then treated with heat to precipitate the lipoproteins from the extracted solution. The optimal pH for the phosvitin extraction from yolk granules was determined, and the iron-binding ability of the extracted phosvitin (final product) was tested. Adding 10% $(NH_4)_2SO_4$ disrupted the granules, and the subsequent thermal treatment at $90^{\circ}C$ for 1 h precipitated low density and high density lipoproteins, which enabled separation of phosvitin by centrifugation. The phosvitin concentration in the extract was significantly higher when the pH of the solution was adjusted to pH ${\geq}9$. The purity and recovery rate of phosvitin at the end of the separation process were approximately 78% and 56%, respectively. The separated phosvitin was confirmed to have ferrous and ferric iron binding ability. The advantages of this new method compared with the traditional methods include no organic solvents and high-priced equipment are needed for the separation. Also, this method is more environment and consumer friendly than that of the traditional methods.

Residual Pesticide Analysis Method of Edible Oil via Heat Distillation Methods (가열증류법에 의한 식용유지의 잔류농약 분석법 개발)

  • Mi-Hui Son;Jae-Kwan Kim;Young-Seon Cho;Na-Eun Han;Byeong-Tae Kim;Myoung-Ki Park;Yong-Bae Park
    • Journal of Food Hygiene and Safety
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    • v.38 no.3
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    • pp.89-98
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    • 2023
  • Currently, no guidelines exist regarding the maximum residues of pesticides in edible oil which is a processed food commonly consumed in Korea. This lack of guidelines hinders the evaluation of the safety of edible oil in terms of pesticide contamination. In this study, an analysis method based on heat distillation and GC-MS/MS was established by optimizing the extraction and purification procedure for 68 pesticides. Important variables in the thermal distillation procedure included heating temperature and time, and we found the nitrogen flow rate as a mobile phase and the type of dissolving solvent were not considerably affected. The determination coefficient (R2) of the residual pesticide was 0.99 or higher, and the quantitative limit (LOQ) was 0.01-0.02 mg/L. The average recovery rate (n=5) was 66.1-120.0% and the relative standard deviation was lower than ±10% when 68 pesticides were spiked at concentrations of 0.01-0.02, 0.1, and 0.5 mg/L. In addition, the within-laboratory precision was less than ±11%, meeting the Korea Food and Drug Safety Evaluation Institute's Guidelines on Standard Procedures for Preparing Food Testing Methods (2016). Therefore, the test method developed in this study can be used as a test method for managing the safety of the residual pesticide concentration in edible oil.

Simultaneous HPLC Analysis of Three Flavonoids in the Extracts of Artocarpus heterophyllus Heartwoods

  • Septama, Abdi Wira;Panichayupakaranant, Pharkphoom
    • Natural Product Sciences
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    • v.22 no.2
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    • pp.77-81
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    • 2016
  • A reversed-phase high-performance liquid chromatographic method is described for the simultaneous determination of three antibacterial flavonoids, artocarpanone, artocarpin, and cycloartocarpin in ethyl acetate extracts from Artocarpus heterophyllus heartwoods. Separation was achieved using a TSK-gel ODS-80Tm column ($5{\mu}m$, $4.6{\times}150mm$) at $25^{\circ}C$ with a gradient elution system of methanol and water as follows: 0-8 min, 60:40; 8-27 min, 80:20; 27-35 min, 60:40, v/v, at a flow rate of 1 mL/min, and a quantitative UV detection at 285 nm. The method was validated by measuring the key parameters, including specificity, linearity, sensitivity, accuracy, repeatability and reproducibility. A high degree of specificity and sensitivity was achieved. The calibration curves for all three flavonoids showed good linearity with a coefficient of determinations ($R^2$) of ${\geq}0.9995$. The recoveries of the method were from 98-104%, with good reproducibility and repeatability (RSD values of less than 2%) were also achieved. Ethyl acetate was the best solvent for extraction of these three flavonoids using the heat reflux conditions for 1 h. This optimized sample preparation and HPLC method can be practically used for a routine standardization process of the extracts from the A. heterophyllus heartwoods.

Cooling Performance of Horizontal Type Geothermal Heat Pump System for Protected Horticulture (시설원예를 위한 수평형 지열 히트펌프의 냉방성능 해석)

  • Ryou, Young-Sun;Kang, Youn-Ku;Kang, Geum-Chun;Kim, Young-Joong;Paek, Yee
    • Journal of Bio-Environment Control
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    • v.17 no.2
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    • pp.90-95
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    • 2008
  • It has become a big matter of concerns that the skill and measures against reduction of energy and cost for heating a protected horticultural greenhouse were prepared. But in these days necessity of cooling a protected horticultural greenhouse is on the rise from partial high value added farm products. In this study, therefore, a horizontal type geothermal heat pump system with 10 RT scale to heat and cool a protected horticultural greenhouse and be considered to be cheaper than a vertical type geothermal heat pump system was installed in greenhouse with area of $240\;m^2$. And cooling performances of this system were analysed. As condenser outlet temperature of heat transfer medium fluid rose from $40^{\circ}C$ to $58^{\circ}C$, power consumption of the heat pump was an upturn from 11.5 kW to 15 kW and high pressure rose from 1,617 kPa to 2,450 kPa. Cooling COP had the trend that the higher the ground temperature at 1.75 m went, the lower the COP went. The COP was 2.7 at ground temperature at 1.75 m depth of $25.5^{\circ}C$ and 2.0 at the temperature of $33.5^{\circ}C$ and the heat extraction rate from the greenhouse were 28.8 kW, 26.5 kW respectively at the same ground temperature range. 8 hours after the heat pump was operated, the temperature of ground at 60 cm and 150 cm depth buried a geothermal heat exchanger rose $14.3^{\circ}C$, $15.3^{\circ}C$ respectively, but the temperature of ground at the same depth not buried rose $2.4^{\circ}C$, $4.3^{\circ}C$ respectively. The temperature of heat transfer medium fluid fell $7.5^{\circ}C$ after the fluid passed through geothermal heat exchanger and the fluid rejected average 46 kW to the 1.5 m depth ground. It analyzed the geothermal heat exchanger rejected average 36.8 W/m of the geothermal heat exchanger. Fan coil units in the greenhouse extracted average 28.2 kW from the greenhouse air and the temperature of heat transfer medium fluid rose $4.2^{\circ}C$after the fluid passing through fan coil units. It was analyzed the accumulation energy of thermal storage thank was 321 MJ in 3 hours and the rejection energy of the tank was 313 MJ in 4 hours.

Parametric Study for the Optimal Integration Design between the Gas Turbine Compressor and the Air Separation Unit of IGCC Power Plant (석탄가스화 복합발전플랜트 가스터빈 압축기와 공기분리장치 간의 최적 연계설계를 위한 매개변수연구)

  • Lee, Chan;Kim, Hyung-Taek
    • Journal of Energy Engineering
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    • v.5 no.2
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    • pp.160-169
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    • 1996
  • Parametric studies are conducted for optimizing the integration design between gas turbine compressor and air separation unit (ASU) of integrated gasification combined cycle power plant. The present study adopts the ASU of double-distillation column process, from which integration conditions with compressor such as the heat exchanger condition between air and nitrogen, the amount and the pressure of extracted air are defined and mathematically formulated. The performance variations of the compressor integrated with ASU are analyzed by combining streamline curvature method and pressure loss models, and the predicted results are compared with the performance test results of actual compressors to verify the prediction accuracy. Using the present performance prediction method, the effects of pinch-point temperature difference (PTD) in the heat exchanger, the amount and the pressure of extracted air on compressor performances are quantitatively examined. As the extraction air amount or the PTD is increased, the pressure ratio and the power consumption of compressor are increased. The compressor efficiency deteriorates as the increase of the flow rate of air extracted at higher pressure level while improving at lower pressure air extraction. Furthermore, through the characteristic curve between generalized inlet condition and efficiency of compressor, optimal integration condition is presented to maximize the compressor efficiency.

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Optimization of Extraction Method for the Quantitative Analysis of Gallic Acid from Cornus officinallis (산수유로부터 gallic acid 추출 및 HPLC에 의한 정량분석)

  • Jang, Mi;Kim, Yeon-Ju;Min, Jin-Woo;Yang, Deok-Chun
    • Korean Journal of Food Science and Technology
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    • v.41 no.5
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    • pp.498-502
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    • 2009
  • Cornus fructus has been used as a tonic, astringent, and haemostatic agent in Korea, China, and Japan. In this study, the fruit of Cornus officinalis was treated with different osmotic pressures, pH values, heat, and ethanol percentages in order to establish optimum extraction conditions for gallic acid, an example of a hydrolyzable tannin. The extract was analyzed by HPLC and LC-MS/MS to identify the gallic acid. As a result, the highest extraction rate of gallic acid (1.57 mg/g) occurred when the Cornus fructus was extracted with 100% ethanol for 1 hr at $80^{\circ}C$. Also, when it was treated with 70% ethanol for 24 and 48 hr, contents of gallic acid were 1.35 and 1.50 mg/g, respectively.

Antioxidant and Elastase Inhibitory Effects of Equisetum hyemale Extract (속새(Equisetum hyemale) 추출물의 항산화 및 Elastase 저해 효과)

  • Song, Jin Hwa;Song, Hyun Sook;Lee, Geo Lyong
    • Journal of Naturopathy
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    • v.10 no.2
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    • pp.86-92
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    • 2021
  • Background: The presence of antioxidants was not confirmed in the medicinal plant Equisetum hyamale grass. Purposes: This study was to determine the antioxidant and elastase inhibition effects of extracts of E. hyemale. Methods: Antioxidant functions of E. hyemale stems and roots were measured and extracted with hot water (HW) and ethyl alcohol (70EOH, 100EOH). Results: The extraction yield of stems was higher in HW extraction than in ethyl alcohol extraction. The polyphenol content was significantly higher in the root extract than in the stem. Total flavonoid content of 70EOH extract was significantly higher in root extract than in stem. The elastase inhibitory function of the extract was 46% in the root and 49% in the stem at 100 ppm of the extract. The ABTS free radical scavenging function was in the order of HW<70EOH<100EOH

Effects of Processing Methods and Variety of Rapeseed Meal on Ruminal and Post Ruminal Amino Acids Digestibility

  • Chen, Xibin;Qin, S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.6
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    • pp.802-806
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    • 2005
  • The objective of this study was to determine the effects of processing method and rapeseed variety on ruminal and intestinal protein digestibility of rapeseed meal in steers. Intestinal amino acid digestibility was assessed with an in situ ruminal incubation and precision-fed rooster bioassay. In this experiment one traditional rapeseed meal sample (sample A, prepress extraction) and three double low rapeseed meal samples (sample B, prepress extraction, sample C, screw press and sample D, low temperature press) were placed in polyester bags(8 cm${\times}$12 cm) and suspended in the ventral rumen of steers for 16 h. The residues of in situ incubations were intubated to roosters. Total excreta were collected for 48 h after incubation and then desiccated and amino acid concentrations were determined. Results showed that in ruminal incubation the degradation rate of amino acid and crude protein was higher for traditional rapeseed meal sample A than for double low rapeseed meal sample B, but was much lower than for double low sample C and D. In the group of double low rapeseed meal samples, sample D processed by low temperature press had the highest degradation rate of amino acids in the rumen. For all amino acids, the digestibility of the residual protein as measured by the precision-fed rooster bioassay tended to be lower for sample B than for sample A, which had the same processing method with sample B, and in the group of double low rapeseed meals, sample B had similar digestibility of amino acid in residual protein to sample D and higher than that of sample C. However, although the total amino acid availability involving the digestibility of amino acids in the rumen and rooster bioassay of double low rapeseed meal sample D (low temperature press) was higher than those of the other three samples by 7 to 9 percent, there were no significant differences. Results indicated that processing method markedly affected ruminal and post ruminal amino acid digestibility of rapeseed meal when the temperature exceeded 110$^{\circ}C$. Rapeseed meal that had a high content of fiber was not suitable for dry heat treatment at higher temperatures or the amino acids digestibility in rumen and total availability of amino acids could be reduced. Results also suggested the variety of rapeseed meal had no significant effect on the digestibility and availability of amino acids.