• Journal of Environmental Health Sciences
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• v.29 no.2
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• pp.50-55
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• 2003

3,3-dichlorobenzidine is suspected to be cancinogenic in experimental animal and human. Several studies have investigated excretion of metabolites in urine, hemoglobin adduction and cancer incidence among workers occupationally exposed to 3,3'-dichlorobenzidine. In these researches, metabolites of 3,3'-dichlorobenzidine had a very important role, and were required as highly purity. The purpose of this study was synthesis and isolation of its metabolites from 3,3'-dichlorobenzidine. 3,3'-dichlorobenzidine was partially dissolved in benzene, ether, ethanol and methanol, and completely dissolved in 70% acetic acid on mixtures of citric acid containing less than 1% DCB, pyridine, a mixture of 0.5N NaOH and toluene(1:2), and phenol saturated with 20 mM TRIZA base. DCB, monoacetyl-DCB and diacetyl-DCB were measured by using gas chromatography/mass spectrometry(GC/MS). Detection for checking them was nitrogen phosphorous detection mode(NPD), and for identifying them was selected ion monitoring mode(SIM). The base peaks were 252 m/z in DCB, 252, and 294 m/z in monoacetyl-DCB, and 252, 294 and 336 m/z in diacetyl-DCB, respectively. Diacetyl-DCB was synthesized by titrating DCB solution of pyridine with sufficient acetyl chloride. Precipitation was diacetyl-DCB, which was purity of 98.7%. And its supernatant was composed of DCB, monoacetyl-DCB and diacetyl-DCB. By using acetic acid as controller of acetylation, monoacetyl-DCB was isolated from diacetyl-DCB . And residual pyridine was removed by using acetone. The purity of monoacetyl-DCB was 98.8%.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.23 no.2
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• pp.129-132
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• 2012

Background and Objectives : MPT is directly related to degree of glottal closure. So it is widely used in the assessment of glottal closure with unilateral vocal fold paralysis. But MPT could be influenced not only by glottal closure but also by pulmonary function. So MPT might not reflect glottal closure in UVFP with decreased pulmonary function. The purpose of the study is to evaluate usefulness of MPT and ratio of /s/ time to /z/ time before and after injection laryngoplasty in UVCP with decreased pulmonary function. Materials and Methods : This study involved 34 patients with unilateral vocal fold paralysis : with decreased pulmonary function in group A (n=15) : with normal pulmonary function in group B (n=19). All patients underwent injection laryngoplasty. Paramters of perceptual analysis, acoustic analysis, aerodynamic analysis, videostroboscopy were compared between two groups. Results : Breathness and asthenic scale, G scale of perceptual analysis were significantly improved in both groups. Glottal gap index were significantly decreased after injection in both groups. In aerodynamic analysis, MPT was improved after injection laryngoplasty in both groups, but S/Z ratio was improved only in group B. In correlation analysis, /s/ time was not correlated with pulmonary function. Conclusion : S/Z ratio reflects neither the pulmonary function nor the glottal clousure properly. MPT is more useful indicator than S/Z ratio to evaluate vocal fold paralysis even with decreased pulmonary function.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.5
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• pp.589-598
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• 1995

Filtering rates of Crassostrea gigas were experimentally investigated with reference to effects of water temperature and size. Absorptiometric determinations of filtering rates with oysters being fed diatom Chaetoceros calcirtans were carried out in a closed system. Optical density of 675nm in path length 100mm cell used as the indication of food particles absorption was appeared directly In proportion with the concentration of diatom pigment $chlorophyll-\alpha$. In the closed system where $C_0$ is $OD_{675}$ at initial time 0, $C_t$, at time t, and Z is the decreasing coefficient of OD as meaning of instantaneous removal speed, then $C_t=C_0{\cdot} e^{-2t}$, $Z=In(C_t/C_0)/t$. On the assumption that the filtering rate is constant, then removal rate per unit time (d) is $d=-e^{-z}$. If t is used to time unit of hour (hr), the filtering rate (FR) in I/hr is given by $FR=V{\cdot}d=V(1-e^{-z})$, where V is the water volume (I) of the experimental vessel. Filtering rate increased as exponential function with increasing temperature while not over critical limit. The critical temperature for filtering rate was assumed to be between $28^{\circ}C$ and $29^{\circ}C$. And the weight exponent for filtering rate is 0.223. The model formula derived from the results as FR, $Ihr^{-1}$ = $Exp(0.208{\cdot}T-4.324){\cdot} (DW)^{0.223}$ (T<29 $^{\circ}C)$ where T is water temperature $(^{\circ}C

• Science of Emotion and Sensibility
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• v.5 no.2
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• pp.23-28
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• 2002

The purpose of this study was to classify apparel fabrics according to rustling rounds and to analyze their transformed colors and mechanical properties. The rustling sounds of apparel fabrics were recorded and then transformed into colors using Mori's color-transforming program. The specimens were clustered into five groups according to sound properties, and each group was named as ‘Silky’,‘Crispy’,‘Paper-like’,‘Worsted’, and ‘Flaxy’, respectively. The Silky consisted of smooth and soft silk fabrics had the lowest value of LPT, $\Delta$f, ARC , loudness(B) and sharpness(z). Their transformed colors showed lots of red portion and color counts. The Crispy with crepe fabrics showed relatively low loudness(z) and sharpness(B), but diverse colors and color counts were appeared. The Paper-like showed the highest value of LPT, $\Delta$f and loudness(z). The Worsted composed of wool and wool-Like fabrics showed high values of LPT, $\Delta$f, loudness(z) and sharpness(B). The transformed rotors of the Paper-like and Worsted showed the blue mostly but color counts were less than the others. The Flaxy with rugged flax fabric had the highest fluctuation strength, and their transformed colors showed diversity.

• Restorative Dentistry and Endodontics
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• v.33 no.5
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• pp.457-462
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• 2008

"Residual stress" can be developed during polymerization of the dental composite and it can be remained after this process was completed. The total amount of the force which applied to the composite restoration can be calculated by the sum of external and internal force. For the complete understanding of the restoration failure behavior. these two factors should be considered. In this experiment. I compared the residual stress of the recently developed nanofilled dental composite by ring slitting methods. The composites used in this study can be categorized in two groups. one is microhybrid type-Z250, as control group, and nanofilled type-Grandio, Filtek Supreme. Ceram-X, as experimental ones. Composite ring was made and marked two reference points on the surface. Then measure the change of the distance between these two points before and after ring slitting. From the distance change, average circumferential residual stress $({\sigma}{\theta})$ was calculated. In 10 minutes and 1 hour measurement groups, Filtek Supreme showed higher residual stress than Z250 and Ceram-X. In 24 hour group, Filtek showed higher stress than the other groups. Following the result of this experiment, nanofilled composite showed similar or higher residual stress than Z250, and when comparing the Z250 and Filtek Supreme, which have quite similar matrix components. Filtek Supreme groups showed higher residual stress.

• The Journal of the Convergence on Culture Technology
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• v.10 no.5
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• pp.445-452
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• 2024

Through the pandemic, the topography of dining culture is rapidly changing due to the advancement of the food delivery market. Competition in the domestic market is intensifying as Coupang Eats recently surpassed Yogiyo and jumped to second place, and Baedal Minjok(Baemin), the industry's No. 1 company, is also preparing to introduce a subscription system. While the growth of the delivery market is slowing, the use of takeout and pick-up services is increasing due to rising delivery costs and food prices. From Generation Z's perspective, the main factors influencing the active use of app services were identified through prior research as usability and convenience, cost sensitivity, and hedonic motivation. While, they are leading the trend of minimizing spending through 'stepping stone consumption' and delivery pot process instead of choosing a subscription system. Accordingly, we aim to provide customers with a better experience and help strengthen competitiveness by proposing ways to improve and revitalize new delivery apps that reflect the characteristics of Gen.Z. As a result of the expert Delphi survey, we will receive impact evaluation scores in the following order: direct view of accumulated discounts, addition of family benefits, coupon reinforcement, SNS promotion, pick-up walk, in-store promotion, and discount rate display, and review their application to practice. It presents academic and policy implications regarding the food tech market.

• Bulletin of the Korean Chemical Society
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• v.16 no.9
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• pp.835-839
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• 1995

Mer,trans-Re(≡NC6H5)(PPh3)2Cl3, Ⅰ, reacted with trimethylphosphine to give a mixture of two stereoisomers, mer,trans-Re(≡NC6H5)(PMe3)2Cl3,Ⅱ, and fac,cis-Re(≡NC6H5)(PMe3)2Cl3, Ⅲ. These compounds could also be prepared from the reaction of Re(≡NC6H5)(PMe3)(PPh3)Cl3 with trimethylphosphine. In both reactions the mer,trans-isomer is a major product. The products have been characterized by NMR, elemental analysis, and X-ray crystallography. Crystal data for Ⅱ: monoclinic space group P21, a=10.053(1) Å, b=10.844(1) Å, c=10.058(2) Å, β=113.45(2)°, Z=2, R(wR2)=0.0348 (0.0894). Crystal data for Ⅲ: monoclinic space group P21/n, a=7.183(2) Å, b=16.983(4) Å, c=15.543(4) Å, β=90.38(2)°, Z=4, R(wR2)=0.0603 (0.1484).

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.43.2-43.2
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• 2015

The massive limit of black holes (BHs) is observed as present day ten billion solar masses. We search for observational signatures of BHs that become extremely massive (EMBHs, 1-10 billion solar masses). I will report on the evolution of active galactic nuclei (AGNs) through the growth of BH mass and their dust emission strength. First, we measured 26 EMBH masses of quasars at 1

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.6
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• pp.1865-1871
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• 2015

Ship's trim is the one of the most important factor for safety at the sea. Turning circle test and Z-test were carried out to find the effect of ship's trim and draft changes. The results are as follows. 1. If the ship's draft and trim became large, turning circle would be wide. 2. If the ship's draft and trim became large, ship's drift angle would be small. Small drift angle made wide turning circle. 3. Trim by the head made slow ship's final speed when turning circle test. 4. By Z-test, the deeper draft and trim by the stern made small OSA. Small OSA means strong ship's stability. 5. Totally 2nd OSA is smaller than 1st OSA on Z-test. 6. There were small differences of 2nd OSA in trim by the stern, but there were large OSA in trim by the head. 7. The larger trim by the stern, the smaller OSW. The small OSW means better ship's stability and maneuverability.

• Journal of muscle and joint health
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• v.13 no.1
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• pp.43-52
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• 2006

Objective: The purpose of this study was to determine the effect of stretching exercise on depression, pain, and fatigue in patients with systemic lupus erythematosus(SLE). Methods: The study was designed as a non-equivalent control group pre-posttest quasi-experimental design. The patients with SLE who signed the consent form were conveniently assigned into two groups(11 experimental subjects and 10 control subjects). The subjects in the experimental group were participated in 6 weeks stretching exercise program for one and a half hours per session twice a week. The data were analyzed by using a SAS-pc+ 8.01 program. Results: 'The experimental group would have less depression scores than the control group' was supported (Z=2.2, p=.025). 'The experimental group would have less pain scores than the control group' was supported (Z=3.4, p=.001). 'The experimental group would have less fatigue scores than the control group' was supported (Z=-2.0, p=.041). With this study, we identified the stretching exercise program was effective on depression, pain, and fatigue of SLE patients. Conclusions: From above results, 6 weeks stretching exercise program could be an effective nursing intervention to reduce depression, pain, and fatigue in patients with SLE.