• Title/Summary/Keyword: Residual solid

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Matrix Solid-Phase Dispersion (MSPD) Isolation and Liquid Chromatographic Determination of Residual Furazolidone in Eggs (MSPD 전처리법과 HPLC를 이용한 Furazolidone의 계란내 잔류분석)

  • 서계원;이재일;이채용;이정치
    • Journal of Food Hygiene and Safety
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    • v.18 no.2
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    • pp.43-50
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    • 2003
  • A liquid chromatographic method, using matrix solid-phase dispersion (MSPD) is developed for the extraction of residual furazolidone in chicken eggs. Blank or fortified egg samples (0.5 g) were blended with Octadecylsilyl (Bulk $C_{18}$, 40${\mu}{\textrm}{m}$, 18%. load, endcapped. 2 g) derivatized silica. After homogenization, $C_{18}$/egg and Na$_2$S $O_4$matrix were transferred to a column made of 10 ml glass syringe and filter paper and compressed 4.0∼4.5 ml volume. The column was washed with 8 ml of hexane and dried under $N_2$ gas. Furazolidone was eluted with acetonitrile (8 ml) under gravity. The eluate containing furazolidone was free from interfering compounds when analyzed by HPLC with UV detection (365 nm, photodiode array). Calibration curves were linear (r = 0.99985) and inter- (1.47%) and intra-assay (5.29%) variabilities for the concentration range examined (7.8∼497 ng/g of eggs, 20 ${mu}ell$ injection volume) were indicative of an acceptable methodology for the analysis of furazolidone. Average recovery of furazolidone added to egg was 96.2%. The limit of detection for the proposed method was 1 ng/g for furazolidone. The method using MSPD is proposed as an alternative assay to the classical method which involves the use of large volumes of a harmful solvent and requires a long tedious separation and clean-up processes prior to its determination.

Study on Co-incineration of Municipal Solid Waste and Organic Sludges (도시쓰레기와 유기성 하수 슬러지 혼합소각에 관한 연구)

  • Jurng, Jong-Soo;Chin, Sung-Min
    • 한국연소학회:학술대회논문집
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    • 2005.10a
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    • pp.238-244
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    • 2005
  • This study performs the pilot-plant experiments to evaluate the effect of the oxygen enrichment on the co-incineration of municipal solid waste and organic sludge from a wastewater treatment facility. The design capacity of the stoker-type incinerator pilot-plant is 150 kg/h. Combustion chamber temperatures were measured as well as the stack gas concentrations, i.e., NOx, CO, and the residual oxygen. The maximum ratio of organic sludge waste to the total waste input is 30%. Also the oxygen-enriched air with 23% of oxygen in supplied air is used for stable combustion. As the co-incineration ratio of the sludge increased up to 30% of the total waste input, the primary and the secondary combustion chamber temperature was decreased $to900^{\circ}C$ (primary combustion chamber), $750^{\circ}C$(secondary combustion chamber), respectively, approximately $200^{\circ}C$ below the incineration temperature of the domestic waste only (primary: $1,100^{\circ}C$, secondary: $950^{\circ}C$). However, if the supplied air was enriched to 22% oxygen content in air, the incinerator temperature was high enough to burn the waste mixture with 30% sludge, which has the heating value of 1,600 kcal/kg.

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Crystal structure refinement and synthesis of $LiAl_5O_8-LiFe_5O_8$ ($LiAl_5O_8-LiFe_5O_8$ 합성과 결정구조 해석)

  • 조남웅;김찬욱;장세기;유광수
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.7 no.2
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    • pp.244-252
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    • 1997
  • The pseudo-spinel type solid solution, $LiAl_{2.5}/Fe_{2.5}O_8$ was prepared by reaction of $LiCO_3, Al_2O_3, Fe_2O_3$ mixture at 1620K, which can be used for cathode material in lithium batteries. Its structure was investigated by Rietveld profile-analysis of XRD in detail. The space group of solid solution is $P4_3$32(a=8.1293$\AA$) and the final residual index of structure refinement was about 5%. Cations $Al^{3+}, Fe^{3+}$ are located at both tetra- and octahedral-coordination and $Li^+$ ions are occupied in the octahedral 4b-, 12d-site of the inverse spinel.

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Study on the sintering Behavior of Mechanecally Alloyed 75W-25Cu Powder Using a Dilatometry Technique

  • Lee, Seong-;Hong, Moon-Hee;Kim, Eun-Pyo-;Houng-Sub;Noh, Joon-Woong
    • Proceedings of the Materials Research Society of Korea Conference
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    • 1992.05b
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    • pp.126-126
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    • 1992
  • Solid and liquid sintering behaviors of mechanically alloyed 75W-25Cu powders have been studied by using a dilatometry technique. The sintering was performed under hydrogen atmosphere of 1 atm with a heating rate of 3 $^{\circ}C$/min. The mechanically alloyed 75W-25Cu powders were prepared by high energy ball milling process under argon atmosphere of 1 atm with alloying times of 0 to 400 h. To compare with the sintering behaviors of mechanically alloyed powders, pure Cu and W powders were also sintered under the above conditions, As the mechanical alloying time increased from 0 to 400 h, the shrinkage behavior of the alloyed powders was enhanced during the sintering, and staring temperature of liquid sintering decreased from 1083 to 1068 $^{\circ}C$. The saturation temperature, above which the shrinkage was completed, of liquid phase sintering decreased from 1248 to 1148 $^{\circ}C$ with increasing mechanical alloying time from 200 to 400 h. The residual stress of the mechanically alloyed powder was measured by X-raydiffractometer. The microstructure of sintered spcimen was observed by optical and scanning electron microscope. From these results, variations of solid and liquid sintering behaviors with mechanical alloying time were discussed in terms of the amount of residual stress and the distribution of W and Cu powders in the mechanically alloyed powder.

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Development of Treatment Process for Residual Coal from Biosolubilization

  • Rifella, Archi;Shaur, Ahmad;Chun, Dong Hyuk;Kim, Sangdo;Rhim, Young Joon;Yoo, Jiho;Choi, Hokyung;Lim, Jeonghwan;Lee, Sihyun;Rhee, Youngwoo
    • Clean Technology
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    • v.24 no.2
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    • pp.119-126
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    • 2018
  • This study introduced a treatment process that was developed to treat Indonesian low-rank coal with high-ash content, which has the same characteristics as residual coal from the biosolubilization process. The treatment process includes separation of ash, solid-liquid separation, pelletizing, and drying. To reduce the ash content, flotation was performed using 4-methyl-2-pentanol (MIBC) as frother, and kerosene, waste oil, and cashew nut shell liquid (CNSL) as collectors. The increasing amount of collector had an effect on combustible coal recovery and ash reduction. After flotation, a filter press, extruder, and an oven drier were used to make a dried coal pellet. Then another coal pellet was made using asphalt as a binder. The compressive strength and friability of the coal pellets were tested and compared.

Simultaneous detection of residual fungicide in Bean Sprouts by Solid-phase Extraction (고체상 추출법에 의한 콩나물 중의 잔류농약 동시 검출)

  • Lee, Myunghwoon;Lee, Taejoon;Pyo, Dongjin
    • Analytical Science and Technology
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    • v.6 no.5
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    • pp.509-514
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    • 1993
  • Benomyl, topsin-M and thiram been known as one of the seed disinfectant. For these studies benomyl, topsin-M and thiram simultaneously had been analyzed by high performance liquid chromatographic method using ODS cartridge, benomyl, topsin-M and thiram was chromatographed using an ODS column and eluent 40% Acetonitrile at a flow rate of 1ml/min. The UV Detector responses at 276nm.

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Numerical Analysis of Shrinkage Cavity Formation using the Modified Fluid Critical Solid Fraction Method (유동한계 고상율법을 이용한 수축공 생성의 수치해석)

  • Lee, Jae-Kyung;Choi, Jeong-Kil;Hong, Chun-Pyo
    • Journal of Korea Foundry Society
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    • v.18 no.6
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    • pp.555-562
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    • 1998
  • Modified fluid critical solid fraction method was utilized as a prediction parameter to describe the shrinkage formation including the position, shape and amount of shrinkage cavities. A numerical scheme was implemented adapting this method for the evaluation of solidification defects in various casting processes. In the present numerical code, the form of shrinkage cavity can be simultaneously determined when an isolated loop is predicted to occur by the fluid critical solid fraction method. An auxiliary parameter, shrinkage potential, was also used in order to calculate the amount of residual liquid during solidification. Solidification analysis was carried out for the validation of the present scheme. It was shown that the calculated results were in good agreement with those of practical casting runs in all of the casting processes envolved in the present research. It may be concluded that the present program successfully predicts the detailed shrinkage formation behavior without the consideration of interdendritic fluid flow analysis.

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Flow Simulation and Deformation Analysis for Injection Molded Plastic Lenses using Solid Elements (입체요소를 사용한 플라스틱 렌즈의 사출성형 및 후변형 해석)

  • Park, Geun;Han, Chul-Yup
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.784-787
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    • 2003
  • The present work covers three-dimensional flow simulation and deformation analysis of injection molded plastic lenses using solid elements. A numerical scheme to evaluate part deformation has been proposed from the results of injection molding analysis. Proposed scheme has been applied to the injection molding processes of optical plastic lenses: a spherical lens and an aspheric lens for a photo pick-up device. Through the simulation processes. residual stress is estimated and the final deformed patters are obtained for both products. The reliability of the proposed approach has also been verified in comparison with the results of real experiments.

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Analysis of Residual Furan in Human Blood Using Solid Phase Microextraction-Gas Chromatography/Mass Spectrometry (SPME-GC/MS)

  • Lee, Yun-Kyung;Jung, Seung-Won;Lee, Sung-Joon;Lee, Kwang-Geun
    • Food Science and Biotechnology
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    • v.18 no.2
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    • pp.379-383
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    • 2009
  • For an accurate risk assessment of furan, a potential human carcinogen, levels must be determined in human blood plasma using a simple and robust assay. In this study, solid phase microextraction-gas chromatography/mass spectrometry (SPME-GC/MS) was used to analyze blood plasma levels of furan in 100 healthy individuals who consumed a normal diet. The subjects were 30 to 70 years of age and 51% were women. Ultimately, an analytical method was established for analyzing furan in human blood. The limit of quantification (LOQ) and furan recovery rate in blood were 1.0 ppb and 104%, respectively. Finally, furan was detected in 21 individuals (13 males, 8 females) with levels ranging up to 17.86 ppb (ng furan/g food).