• The Korean Journal of Vision Science
• /
• v.20 no.4
• /
• pp.413-420
• /
• 2018

Purpose : We present a novel method for the analysis of blue light applied by the analysis method of David L. with optical experiment and blue light by measuring the transmittance by dividing it by the refractive power in the spectacle lens made by MR8. Methods : The lenses of -8.00D, -7.00D, -6.00D, -5.00D, -4.00D, -3.00D, and 0.00D manufactured by MR8 being sold in the market, were selected. The transmittance was measured at the intervals of 5 nm from 200 to 1000 nm with UV-VIS Spectrophotometers (SolidSpec 3700), and they were in range of the blue light (380 to 500 nm) analyzed by a David L.'s analysis method. Results : All of the MR8 lenses selected for this study almost completely blocked at the UV range. A lens of -8.00D was measured as the lowest transmittance of 59.56% in the blue light area and low values were measured at the blue areas 1 and 2 according to the analysis of David L.In the infrared ray area, the transmittance of all lenses gradually decreased. The average value of the luminous transmittance was 23.67% ~ 26.33% and then gradually decreased from -4.00D. Conclusion : Applying the analysis of David L., a minimum of 41.28% and a maximum of 46.60% were measured at the blue light 1 area and a minimum of 87.30% and a maximum of 97.55% were measured at the blue light 2 area. A minimum of 86.83% and a maximum of 96.55% were measured at the blue light 3 area, and the average was 94%. The luminous transmittance of the -3.00D lens was 26.33%, which was the highest, and that -8.00D was 23.67%, which was the lowest.

• Analytical Science and Technology
• /
• v.29 no.6
• /
• pp.277-282
• /
• 2016

British Pharmacopoeia (BP 2013), the United States Pharmacopoeia (USP 39) and the Korean Pharmacopoeia (KP XI) contain monographs for the quality control of raw diosmin using high performance liquid chromatography (HPLC). However, official monographs detailing pharmaceutical formulations for diosmin are not available in foreign pharmacopoeias. In the KP XI, ultraviolet-visible (UV-Vis) spectroscopy-which is less specific than HPLC-is reported for the testing of diosmin capsules. In this study, we present an alternative HPLC assay for such testing that is more specific than UV-Vis methods. Method validation was performed to determine linearity, precision, accuracy, system suitability, and robustness. The linearity of calibration curves in the desired concentration range was high ($r^2$>0.999), while the RSDs for intra- and inter-day precision were 0.15-0.29 % and 1.05-1.74%, respectively. Accuracies ranged from 101.2-103.2 %, while the retention time and peak area RSDs were 0.37 % and 0.06 %, respectively. Additionally, the plate number and asymmetry factor values for diosmin were 3591.293 and 1.35, respectively. Since the intermediate-precision and robustness of the assay were satisfactory, this method will be a valuable addition to the Korean Pharmacopoeia (KP XI).

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.14 no.2
• /
• pp.73-77
• /
• 2004

The color enhancement for natural Zambian amethyst of low quality was carried out by the hydrothermal treatment method. The hydrothermal treatment conditions were as follows: reaction temperature; $300^{\circ}C$, duration; 30 hrs, filling; 40%, solvent; 6 M-HCI solution. The reddish purple amethyst of high quality was obtained under these conditions. From the result of ICP/AES, it was known that color enhancement was affected by a Fe elemental content to exist in the inside of natural Zambian amethyst. Also, from the result of UY-VIS-NIR, it was shown that the absorption peak at 550 nm after hydrothermal treatment is slightly lower than those of non-treated natural Zambian amethyst. In this study, it was known that hydrothermal treatment method was a way to suitable for increase of commercial value of natural Zambian amethyst.

• Polymer(Korea)
• /
• v.26 no.3
• /
• pp.326-334
• /
• 2002

The purpose of this work was the producing of a biodegradable poly($\varepsilon$-caprolactone) (PCL) microcapsule and the analyzing of form and features for the manufacturing conditions which could be observed in a prospective drug delivery systems (DDS) through drug release. The effects of different stirring rates, stirring times and concentrations of emulsifier for the diameter and form of the microcapsules were observed using image analyzer (IA) and scanning electron microscopy (SEM). As a result, the microcapsules were made in wrinkle and spherical forms with a mean particle size of 40~300$\pm$20 $mu extrm{m}$. PCL microcapsules containing drugs were confirmed using FT-IR spectra. The role of interfacial adhesion between PCL and drug was determined by contact angle measurements. The drug release test of PCL microcapsules was characterized by UV/vis. spectra. It was found that the drug release rate of the microcapsules prepared with high concentration emulsifier was significantly fast.

• Polymer(Korea)
• /
• v.34 no.2
• /
• pp.144-149
• /
• 2010

Ag/polystyrene(PS) nanocomposites were prepared by in situ reduction of silver 2-ethylhexylcarbamate (Ag-CB) complex and follwing radical polymerization only by heating at 110 $^{\circ}C$. In contrast to this conventional heating method, the microwave irradiation afforded well-dispersed silver nanoparticles(NPs) in styrene monomer without polymerization. The synthesis of Ag NPs proceeded uniformly throughout the reaction vessel only under microwave irradiation, completing the reaction simultaneously in the whole reaction solution. Successive polymerization of the monomer containing the resultant NPs has successfully produced a hybrid of the silver NPs dispersed in PS matrix. Ag/PS (0.1/100) nanocomposites were prepared successfully by melt-mixing process using Ag/PS(4.0/100) as a master-batch. UV-VIS spectroscopy, TEM, and X-ray diffraction techniques were used to investigate the process of formation of Ag/PS nanocomposites.

• Applied Chemistry for Engineering
• /
• v.29 no.1
• /
• pp.97-102
• /
• 2018

In this work, the surface of gold nanoparticles (AuNPs) was modified with small molecules including mercaptoundecanoic acid (MUA) and L-lysine for the development of highly sensitive lateral flow (LF) sensors. Uniformly sized AuNps were synthesized by a modified Turkevich-Frens method, showing an average size of $16.7{\pm}2.1nm$. Functionalized AuNPs were then characterized by transmission electron microscopy, UV-vis spectroscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The stable conjugation of AuNPs and antibodies was obtained at pH 7.07 and the antibody concentration of $10{\mu}g/mL$. The functionalized AuNP-based LF sensor exhibited lower detection limit of 10 ng/mL for hepatitis B surface antigens than that of using the bare AuNP-based LF sensor (100 ng/mL).

• Journal of the Korean Applied Science and Technology
• /
• v.32 no.1
• /
• pp.16-22
• /
• 2015

Alkaloids of Vinca minor L. were characterized by HPLC equipped with the photo diode array detector and compared their UV/vis absorption spectra with an index material such as vincamine. UV/vis absorption spectra of more than 9 compounds belong to various classes such as flavonoids were shown and characterized. Extracts with ethanol or hot water were tested against the DPPH (2,2-diphenyl-1-picrylhydrazyl) free-radical to investigate their antioxidant activity. Based on the results, those extracts show about 14-15% of antioxidant activity of quercetine and vitamin C used as standards.

• Polymer(Korea)
• /
• v.27 no.5
• /
• pp.449-457
• /
• 2003

The purposes of this work were the producing of a biodegradable poly($\varepsilon$-caprolactone) (PCL) / poly(ethylene oxide) (PEO) microcapsule and the analyzing of form and features for the manufacturing conditions which could be observed in a prospective drug delivery systems through drug release. The effects of emulsifier, emulsifier concentration, and stirring rate for the diameter and form of the microcapsules were observed using image analyzer and scanning electron microscope. The role of interfacial adhesion between PCL/PEO and drug was determined by contact angle measurements, and the drug release test of the microcapsules was characterized by UV/vis. spectra. As a result, the microcapsules were made in spherical fonns with a mean particle size of 170 nm∼68 $\mu$m. And the work of adhesion between water and PCL/PEO increased with increasing the content of PEO, probably due to the increased the hydrophilicity. It was also found that the drug release rate from the microcapsules significantly increased with increasing the content of PEO, which could be also attributed to the increasing of the hydrophilic groups or the degree of adhesion force at interfaces.

• The Journal of Korean Institute for Practical Engineering Education
• /
• v.4 no.2
• /
• pp.84-90
• /
• 2012

It is described that the total analysis of CD-R, a digital recording media, including the planning and performing chemical analysis of cross sectional structure of recording layer, dye composition and chemical structure as an example of design for chemical analysis. Since chemical analysis of unknown sample is often involved the complicated process requiring many experiences and knowledge, students feel difficulties in planning the procedure of chemical analysis and selecting analytical methods. Thus, an example of chemical analysis is provided here to help student understanding the hole procedure of CD-R analysis. In this study, SEM is used to determine the cross sectional structure of PC substrate and recoding layer of CD-R. The dyes in recording layer is dissolved with solvent and separated with using TLC, analyzed with using UV-Vis absorption spectrometer. Then, the chemical structure of each component is determined with using GC-MS, NMR and mass spectrometer.

• Journal of the Korean Chemical Society
• /
• v.44 no.6
• /
• pp.507-512
• /
• 2000

A new copper(II) complex, Cu(dpb)(NO$_3$)$_2$(H$_2$O) (dpb=2,2'-dipyridylbenzylamine) (1) was synthesized from the reaction of Cu(NO$_3$)$_2$·3H$_2$O and dpb in ethanol solution followed by recrystallization in acetonitrile. The structure of 1 was determined by X-ray diffraction methods. The single crystal structure was characterized as follows: space group P2$_1$/c, Z=4, a=12.501(9)$\AA$, b=9.231(10)$\AA$, c=17.119(6)$\AA$, $\alpha$=90$^{\circ}$, $\beta$=107.33(4)$^{\circ}$, $\gamma$=90$^{\circ}$, V=1885.8(2)$\AA^3$, R$_1$=0.0647, $_{w}R$_2$$=0.1866 for 3258 reflections. Compound was a typical paramagnetic copper(II) complex coordinated by 2,2'-dipyridylamine derivative ligand, which was confirmed by EPR, NMR, UV/VIS, and IR spectroscopy.