• Korean Journal of Environmental Biology
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• v.38 no.2
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• pp.278-288
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• 2020

Rhodomonas salina is a phototrophic marine flagellate. We examined the ultrastructure of R. salina with particular attention to the flagellar apparatus by transmission electron microscopy and compared it with that of other cryptomonads reported previously. The major components of the flagellar apparatus in R. salina were a keeled rhizostyle (Rhs), a striated fibrous root(SR), a SR-associated microtubular root (SRm), a mitochondrion-associated lamella (ML), and three types of microtubular roots (9r, 4r, and 2r). The keeled Rhs originated near the proximal end of the dorsal basal body, passed near the nucleus and dissociated at the posterior end of the cell. The SR and SRm originated between two basal bodies and laterally extended to the right side of the cell. The ML originated between two basal bodies and extended to the left side of the cell. The 9r originated between the ventral basal body and the Rhs and extended toward the anterior dorsal lobe of the cell. The 4r originated near the 9r and extended toward the dorsal lobe with the 2r, which originated between two basal bodies. Here, the flagellar apparatus in R. salina is described, and the ultrastructure of the flagellar apparatus is compared among cryptomonad species.

• Analytical Science and Technology
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• v.22 no.4
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• pp.302-306
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• 2009

A trace amount of boron in steel significantly influences its mechanical and physical properties. A prompt gamma ray activation analysis (PGAA) method is used to measure boron in low alloy steel samples of KRISS 101-01-C21~C26. NIST SRMs of 362, 364, 1761 and 1767 serve as the control standards to validate the measurement method. The measured values of the NIST SRMs are consistent with their certified values within the expected uncertainties, except for that of NIST SRM 362. Experimental uncertainties are evaluated according to the guidelines given by the International Organization for Standardization (ISO). The expanded uncertainties are calculated with a coverage factor of 2, at approximately 95% confidence level. The calculated relative expanded uncertainties of boron mass fractions are between 3% and 7% at the mg/kg level. The results are compared with the results measured by the solvent extraction-inductively coupled optical emission spectrometry (ICP/OES) method.

• Clinics in Shoulder and Elbow
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• v.4 no.2
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• pp.173-180
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• 2001

Aim: To evaluate validity and responsiveness of four shoulder scoring systems. Material and Method: Twenty-five cases of shoulder instability(22 traumatic, 3 non-traumatic) and twenty-three cases of rotator cuff tear(12 small or medium, 10 large or massive) treated surgically were evaluated with the Shoulder Function Score of the University of Pennsylvania(Penn FS), Constant Score, UCLA Shoulder Rating Scale and Simple Shouler Test(SST), preoperatively and at final follow-up. The average follow-up was 16.0 months in instability group and 17.5 months in rotator cuff tear group. Using the SPSS program, Pearson linear correlation coefficiency(PLCC) between the scores were calculated. And to assess the construct validity, PLCC between patients' satisfaction and the scores were also calculated. Responsiveness was measured by the standardized response mean(SRM). Result: In instability group, correlation between the scoring systems was low preoperatively except between Constant and SST, but high after operation. Patients' satisfaction with the scores showed low PLCC preoperativley, but high PLCC postoperatively. SRM was high in PENN and UCLA, but when the satisfaction segment of the score was eliminated from UCLA, the SRM was the lowest. In rotator cuff tear group, there was high correlation between the scores not only preoperatively but postoperatively. And the patients' satisfaction matched well with the scores. SRM was particularly high in UCLA and SST. Even when satisfaction segment was eliminated from UCLA, the SRM was still the highest. Conclusion : Evaluation by the 4 scoring systems investigated in the study showed less consistency in instability than rotator cuff tear in terms of correlation and validity. Responsiveness was generally higher in rotator cuff tear group than in instability group except for Pennsylvania Shoulder Function Score. Therefore it is construed that use of any among the four scoring systems doesn't make difference in evaluation of rotator cuff lesions. However in instability group, care is needed because different result may be obtained according to the selection of a scoring system.

• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.107-109
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• 2007

This paper presents a dynamic force analysis of switched reluctance motor using 2D-transient finite element method. The main exciting of the vibration is the electiromagnetic force in the stator that is calculated Maxwell stress method. The advantage for elimation of vibration of 12/8 SRM was explained by comparing the radial force of 12/8 and 6/4 SRM in both time and frequency domain. In order to effective mitigate the vibration during turning off process, effects of different commutation method were investigated.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.4
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• pp.165-173
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• 2002

The goal of this paper is optimal switching angle of switched reluctance motor drive system fur maximum energy ratio. A new magnetizing method with a low-frequency increasing the energy conversion ratio that is related to the efficiency of motor is proposed. As the results, it improved the efficiency about 2[%]. And a torque ripple is also sufficiently reduced compared with that of the conventional approach. In order tn start softly regardless of large ripple torque, the profile of phase current is predicted by the ANFIS, and current control mode was adapted when it is operated under the starting speed. Variable implementations en the fields will guarantee the more practical drive system.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.212-216
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• 1998

For a Switched Reluctance Motor(SRM) drive, the important things are 1) reducing torque ripple, 2) improving efficiency, 3) sensorless speed control, 4) accurate position. The position information impotant for the efficiency and smoothness drives. Since SRMs characteristics are nonlinear. It is difficult to estimated phase current in saturation region. This paper describes a method for indirect sensing of the rotor position in SRM which use both voltage and current. The method obtains rotor position by using unconducting phase. The information about the rotor position is achieved by differentiating the unconducting phase current or the voltage gradient. And then, this paper presents a torque control with indirect rotor position detection methods. This torque control is achieved by developing a detailed nonlinear model of the motor.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1026-1029
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• 1993

Inherent speed-torque performance of Switched Reluctance Motor is similar to that of series wound DC motor. Thus, the speed of the motor is extremely regulated according to load torque. For the purpose of controlling the speed and torque of SRM it is necessary to change the applied DC link voltage or the switch-ON and switch-OFF angles which control the phase current of the motor. This paper describes speed-torque characteristics of an integral horse power Switched Reluctance Motor by adjusting the switch-ON and switch-OFF angles. Speed at rated load torque can be regulated by adjusting the switching angles and the control scheme is applied to 2kW, 3 phase, 6/4 SRM.

• Analytical Science and Technology
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• v.20 no.1
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• pp.33-40
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• 2007

This study centered on the quantitative analysis of about 27 trace elements including toxic ones using instrumental neutron activation analysis of fine ambient particulate matter in the third and fourth industrial complex area of Daejeon city, Korea. For analytical quality control, the certified reference material (NIST, the National Institute of Standards and Technology, U.S.A., SRM 2783, air particulate on filter media) was used. The errors relative to SRM values of Sb, Mn, V, Mg, Na, K, Ti, Co, Zn, and Sm fell below 5%, while those of Cr, Fe, Ba, Th, Ce, Al, and Cu were less than 10%. From the results of the quantitative analysis, the concentration of toxic metals such as As, Mn, Se, V, and Zn were $3.26{\pm}2.72$, $9.86{\pm}4.71$, $2.18{\pm}1.25$, $4.91{\pm}2.41$, $158{\pm}78ng/m^3$, respectively. And the results of factor analysis indicated that there are no more than six factors of sources of fine ambient particulate with statistical significance in the study area.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.2
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• pp.117-124
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• 2002

This study was carried out to investigate variation of heavy metal contents for feed materials during composting and to evaluate the effect of pre-treatment methods on heavy metal analysis. Dry ashing, $HNO_3-HClO_4$, aqua-regia, HCl reflux, $HNO_3-HClO_4-HF$, autoclaving methods of $HNO_3$, HCl, and $HNO_3(2+1)$ were used as pre-treatment for heavy metal analysis. In analyzing standard material SRM 2781, recovery efficiencies of pre-treatment methods were 50-60% for Cr and Zn, >100% for Ni, and 80-90% for Cd and Cu. Recovery efficiency of dry ashing for SRM 2781 was the lowest. In composting raw material, Cd concentration by autoclaving methods was 3 to 4 times higher than the other methods and recovery efficiency of dry ashing was also the lowest. During composting, Cd content was the highest in autoclaving. Cr and Cu concentrations were the lowest in dry ashing and aqua-regia, respectively. Variation coefficients of Pb and Zn between pre-treatment methods were generally low.

• Analytical Science and Technology
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• v.21 no.6
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• pp.502-509
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• 2008

An ID LC/MS (isotope dilution liquid chromatography/mass spectrometry) was used as a primary method for the quantitative analysis of cholesterol in human serum. The separation of cholesterol was carried out by Thermo ODS hypersil $C^{18}$ column. The mobile phase was 100% methanol, and flow rate was $0.3m{\ell}/min$. Cholesterol and cholesterol-$3,4-13C_2$ were monitored at m/z 369.4 and 371.3, which correspond to $[M-H_2O+H]^+$ respectively. In order to verify the measurement method, NIST SRM 909b was analyzed. The results agreed well with certified values within uncertainty. The four kinds of serum certified reference material were prepared and certified. The repeatabilities of measurement were ranged from 0.1 to 0.8% (RSD), which were relatively good. The reproducibility between independent measurement run was below 0.24% (RSD). The expanded uncertainty was about 1.43% within the 95% confidence interval.