• Title/Summary/Keyword: sample recovery

Search Result 708, Processing Time 0.03 seconds

A Qualitative Research on the Experience and Recovery Process of the Korean Depression (우울증 경험과 회복과정에 대한 질적 연구)

  • Joo, Eunsun;Cho, Young-Im;Kim, Dan-Bi;Kang, Yu-Jin
    • The Journal of the Korea Contents Association
    • /
    • v.17 no.7
    • /
    • pp.505-526
    • /
    • 2017
  • This study explored and described the depression of Koreans for the true nature of the experience and recovery process. The sample included 13 men and women between 18 and 69 who experienced and recovered from depression. Participants attended interviews producing data, which was analyzed using Consensual Qualitative Research(CQR) method. The result yielded 4 domains, the life before depression, the experience of depression, the recovering process of depression, after the recovery of depression.

A study on simultaneous determination of residual sulfonamides in livestock productions by high performance liquid chromatography (HPLC를 이용한 축산식품중 잔류 설폰아미드제의 동시분석법 연구)

  • 황래홍;김영수;윤은선;김기근;이규학
    • Korean Journal of Veterinary Service
    • /
    • v.18 no.3
    • /
    • pp.13-28
    • /
    • 1995
  • This study was carried out to explore the most sensitive and useful method for simultaneous determination of five sulfa drugs(sulfamethazine, sulfamerazine, sulfamonomethoxine, sulfadimethoxine, sulfaquinoxaline) in livestock productions(pork muscle, bovine muscle, chicken muscle, milk ) by HPLC with UV detector and reverse phase column. The results obtained were as follows:1. For mobile phase acetonitrile-0.01M ammonium acetate (23:77) showed more applicable sensitivity and retention times than acetonitrile-1% acetic acid(23:77). Thus acetonitrile-0.01M ammonium acetate(23:77) selected and applied to the modification test, from which it was found pH 6.75 was the most adequate. 2. Optimal wavelength of UV for SMT(sulfamethazine), SMR(sulfamerazine), SMM(sulfamonomethoxine), SD(sulfadimethoxine), and SQ(sulfaquinoxaline) were 266, 266, 265, 269 and 250nm, respectively, and that for simultaneous application it was 263nm. 3. The average recovery rate by extractant(chloroform, dichloromethane, chlorform+dich-loromethane) in the classic method was not significantly different(p>0.05) but that by chloroform higher than the others. Thus chloroform was found to be adequate as extractant in this classic method. 4. The average recovery rate was 86.5% by the MSPD(matrix solid phase disperse) method, which was significantly higher than that by the classic method(p<0.05). Also the recovery rates by method were significantly different(p<0.05) in accordance with sample and type of drug. The MSPD method was much superior to classic method on clean-up.

  • PDF

Determination of Simultaneous Analytical Method of Residual Pesticides by Gas Chromatography (기체크로마토그래피를 이용한 잔류농약 동시다성분 분석법)

  • Choi, Won-Jo;Choi, Gye-Sun;Lee, Hee-Jung;Won, Young-Jun;Park, Heung-Jai;Kim, Woo-Seong
    • Journal of Environmental Science International
    • /
    • v.18 no.12
    • /
    • pp.1369-1381
    • /
    • 2009
  • The simultaneous determination of residual pesticides was developed using a gas chromatography. In this study, a simple and reliable methodology was improved to detect 175 kinds of residual pesticides by a liquid-liquid extraction procedure, followed by chromatographic analysis by gas chromatography. The 175 kinds of residual pesticides was classified into 4 groups according to the chemical structure, column type, resolution and sensitivity. The soybean sample selected for recovery experiment was not detected any pesticides. The recovery rates were ranged from 70.6% to 119.7% in most pesticides. The relative standard deviation (RSD 0.3~5.6%) was lower than 5.6% in all cases. The limits of detection (LOD) was lower than the maximum residue levels established by Korean legislations. The method has been successfully applied to the analysis of approximately 130 real samples.

Image Recovery Using Nonlinear Modeling of Industrial Radiography (산업용방사선영상의 비선형모델링에 의한 영상복구)

  • Hwang, Jung-Won;Hwang, Jae-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.45 no.4
    • /
    • pp.71-77
    • /
    • 2008
  • This paper presents a methodology for recovering the industrial radiographic images from the effects of nonlinear distortion. Analytical approach based on the inverse square law and Beer's law is developed in order to improve a mathematic model of nonlinear type. The geometric effect due to dimensions of the radioactive source appeals on the digitized images. The relation that expresses parameters values(angle, position, absorption coefficient, length, width and pixel account) is defined in this model, matching with the sample image. To perform the search for image recovery most similar to the model, a correction procedure is designed. The application of this method on the radiographic images of steel tubes is shown and recovered results are discussed.

Investigation of Surface Degradation in Silicone Rubber Due to Corona Exposure (코로나 방전에 노출된 고분자 애자용 실리콘 고무의 표면열화)

  • Hong, Joo-Il;Huh, Chang-Su;Lee, Ki-Taek;Hwang, Sun-Mook;Youn, Bok-Hee
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.17 no.10
    • /
    • pp.1068-1078
    • /
    • 2004
  • In this paper we investigated the characteristics of surface degradation in silicone rubber due to corona exposure and recovery mechanism. It was shown that surface free energy was 22.42 mJ/$m^2$ on initial sample but surface free energy was approximately increased to 71.14 mJ/$m^2$ after 45 minutes. However, surface free energy on silicone rubber after corona discharge treatment was completely recovered within a short time due to diffusion of low molecular weight(LMW) silicone fluid. It was shown that corona discharge insured the increase of diffusible LMW chains, which could lead to recover the surface hydrophobicity. 200~370 g/mol distribution of LMW silicone fluid which was extracted by solvent-extraction with gel permeation chromatography (GPC) was contributed to recovery. The surface degradation characteristics on silicone rubbers and the recovery mechanism based on our results were discussed.

Chromium(III) recovery from tanning wastewater by adsorption on activated carbon and elution with sulfuric acid

  • Hintermeyer, Blanca H.;Tavani, Eduardo L.
    • Environmental Engineering Research
    • /
    • v.22 no.2
    • /
    • pp.149-156
    • /
    • 2017
  • Chromium(III) recovery from tanning wastewater by means of adsorption on activated carbon and elution with sulfuric acid was studied. Tests were carried out at laboratory scale on an effluent of industrial origin. Initially, proteinaceous materials and fats were separated via sieving followed by ultrafiltration. The chemical composition of the sample thus precleansed was (in g/L): 1.09 chromium(III); 10.36 sulfate; 11.10 sodium; 9.57 chloride; 0.40 proteinaceous materials; and 0.20 fats. Adsorptions were made at 20, 30, and $40^{\circ}C$, establishing what temperature favored chromium(III) uptake. At $40^{\circ}C$, the maximum cation fixation was 40.2 mg/g, and the lowest content in an equilibrium solution was 3.9 mg/L. As regards sodium, chloride, and sulfate, the concentrations before and after the treatment were similar. Likewise, it was found that protons were also retained, modifying the pH of the liquid medium. Adsorption isotherms were analyzed using the Langmuir, Temkin, and Freundlich models. Finally, the extraction of the adsorbed tanning agent with sulfuric acid was evaluated. A recovery of 96.5% was achieved with 0.9 N at $70^{\circ}C$ (13.23 g/L $Cr^{3+}$; 42.98 g/L sulfate; and 0.40 g/L NaCl).

Histological Analysis Effect of 'Sexiang Shuhuo Jing' for after Skeletal Muscle in Rats (골격근 손상에 대한 '사향서활정(麝香舒活精)' 치료 효과에 대한 조직형태학적 관찰)

  • Kim, Jin-Hang;Song, Je-Ho
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.20 no.6
    • /
    • pp.1543-1547
    • /
    • 2006
  • The aim of this experiment was to observe and analysis clinical effect of the 'Sexiang shuhuo Jing' on histological change for 14days after skeletal muscle injury in rats. The gastrocnemius muscles of rats were damaged by electromechanical and serial cryosections of the damaged muscle were prepared at 1, 5, 10, 14 days after injury. Muscle sample of the both control and 'Sexiang Shuhuo Jing' treated group were prepared for histological analysis by optical microscope and electron microscopy. 'Sexiang Shuhuo Jing' treatment group's skeletal muscle recovery was much more faster than control group. After 5 day's 'Sexiang Shuhuo Jing' treatment group's basically recovery normal structure of muscle fiber. After 14 day's control group's damaged muscle were basically recovery structure of muscle fiber but still has some factor of pathological impression but in Sexiang Shuhuo Jing treatment group's can't be found that.

Prediction of Stand Structure Dynamics for Unthinned Slash Pine Plantations

  • Lee, Young-Jin;Cho, Hyun-Je;Hong, Sung-Cheon
    • The Korean Journal of Ecology
    • /
    • v.23 no.6
    • /
    • pp.435-438
    • /
    • 2000
  • Diameter distributions describe forest stand structure information. Prediction equations for percentiles of diameter distribution and parameter recovery procedures for the Weibull distribution function based on four percentile equations were applied to develop prediction system of even-aged slash pine stand structure development in terms of the number of stems per diameter class changes. Four percentiles of the cumulative diameter distribution were predicted as a function of stand characteristics. The predicted diameter distributions were tested against the observed diameter distributions using the Kolmogorov-Smirnov two sample test at the ${\alpha}$=0.05 level. Statistically, no significant differences were detected based on the data from 236 evaluation data sets. This stand level diameter distribution prediction system will be useful in slash pine stand structure modeling and in updating forest inventories for the long-term forest management planning.

  • PDF

A EMG Signal Analysis by the Short Time Fourier Analysis (시간 푸리에 해석에 의한 근전신호 해석)

  • Shin, Seung-Hyun;Lim, Hyun-Su;Huh, Woong
    • Proceedings of the KOSOMBE Conference
    • /
    • v.1989 no.05
    • /
    • pp.61-65
    • /
    • 1989
  • In this paper, a method of the measument the degree of the musule fatigue by Short Time Fourier Analysis of the EMG signals from human biceps in the action state is proposed. For this purpose, fatigue state and recovery state of 10 persons EMG signals are sampled. And then spectrum centroids are analyzed with respect to the change of sample time window. As result of 10 persons experiment, we know that person A is most good recovery stale.

  • PDF

펌프-촉침 방법을 이용한 피코초 순간 흡광 속도분광기 제작

  • 장두전
    • Korean Journal of Optics and Photonics
    • /
    • v.4 no.3
    • /
    • pp.347-353
    • /
    • 1993
  • A picosecond transient absorption kinetic spectrometer using a pump-probe method is presented and compared with other methods of picosecond transient absorption measurements. This constructed kinetic spectrometer detects the transient transmittance of sample using a lock-in amplifier as a function of delay time between pump and probe pulses generated from a picosecond mode-locked cw dye laser. Typical transient absorption and ground state bleach recovery kinetic profiles measured with this spectrometer are shown. Excellent kinetic curves of transient absorption or ground state bleach recovery may be obtained at single wavelengths with this spectrometer.

  • PDF