• Korean Journal of Microbiology
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• v.17 no.4
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• pp.193-197
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• 1979

Attempts were made to elucidate the process of biodegradation of furfural. Zoogloea sp. isolated from soil could convert furfural into 2-furoic acid by a certain enzyme (s) and also accumulated it extracellularly. This substance was extracted with diethyl ether and identified with U.V. spectrophotometry, high pressure liquid chromatography (HPLC) and IR spectrophotometry.

• Analytical Science and Technology
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• v.15 no.1
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• pp.87-90
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• 2002

The content of $SiHCl_3$ as a trace impurity in $SiCl_4$ was analyzed by Near IR spectrophotometer with optical fiber. The strong absorption bands of $5345{\sim}5116cm^{-1}$ and $4848{\sim}4349cm^{-1}$ were used for analysis of $SiHCl_3$, and the detection limit of impurity $SiCl_3$ was appeared to be 0.005 ％ in the spectrum. The quantitative analysis by Near IR spectrophotometry showed the analytical possibility of trace impurity in $SiCl_4$ without sample pre-treatment not only in the laboratory but also in the field.

• Korean Journal of Microbiology
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• v.23 no.4
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• pp.241-247
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• 1985

The objectives of this study were to isolate and identify ninhydrin positive substande(s) produced in the culture broth of Pseudomonas fluorescens. It was found that the NPS could stimulate bioconversion of furfural into furoic acid. In order to isolate the NPS from the culture broth, cell free filtrate was subjected to ion-exchange chromatography, gel-permeation and finally to cellulose column chromatography. The purified NPS was white amorphous power and very soluble in water, slightly soluble in methanol and very insoluble in organic solvents. UV, and IR absorption spectra. $^H$ and $^{13}C-NMR$ were measured in order to identify the chemical structure of the NPS.

• Journal of the Korean institute of surface engineering
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• v.56 no.4
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• pp.233-242
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• 2023

In recent years, energy-management studies in buildings have proven useful for energy savings. Typically, during heating and cooling, the energy from a given building is lost through its windows. Generally, to block the entry of ultraviolet (UV) and infrared (IR) rays, thin films of deposited metals or metal oxides are used, and the blocking of UV and IR rays by these thin films depends on the materials deposited on them. Therefore, by controlling the thicknesses and densities of the thin films, improving the transmittance of visible light and the blocking of heat rays such as UV and IR may be possible. Such improvements can be realized not only by changing the two-dimensional thin films but also by altering the zero-dimensional (0-D) nanostructures deposited on the films. In this study, 0-D nanoparticles were synthesized using a sol -gel procedure. The synthesized nanoparticles were deposited as deep coatings on polymer and glass substrates. Through spectral analysis in the UV-visible (vis) region, thin-film layers of deposited zinc oxide nanoparticles blocked >95 % of UV rays. For high transmittance in the visible-light region and low transmittance in the IR and UV regions, hybrid multiple layers of silica nanoparticles, zinc oxide particles, and fluorine-doped tin oxide nanoparticles were formed on glass and polymer substrates. Spectrophotometry in the UV-vis-near-IR regions revealed that the substrates prevented heat loss well. The glass and polymer substrates achieved transmittance values of 80 % in the visible-light region, 50 % to 60 % in the IR region, and 90 % in the UV region.

• Advances in nano research
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• v.4 no.4
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• pp.281-294
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• 2016

The advantages of nano-scale materials (size 1-99 nm in at least in one dimension) could be realized with their potential applications in diversified avenues. Herein, we report for the first time on the successful synthesis of homogeneous epoxy coatings containing phytogenic silver nanoparticles (Ag) on PVC and glass substrates by room-temperature curing of fully mixed epoxy slurry diluted by acetone. Alstonia scholaris bark extract was used to reduce and stabilize the silver ions. The surface morphology and mechanical properties of these coatings were characterized using the techniques like, UV-Vis (UV-Visible) spectrophotometry, X-ray diffraction (XRD), Fourier transform infrared spectrophotometry (FT-IR), Epifluorescence microscopy and scanning electron microscopy (SEM). The effect of incorporating Ag nanoparticles on the biofilm (scale) resistant epoxy-coated PVC was investigated by total viable counts ($CFU/cm^2$) from epoxy coating from (Initial) $1^{st}$ day to $25^{th}$ days. The phytogenic Ag nanoparticles were found to be significantly improving the microstructure of the coating matrix and thus enhanced the anti-biofilm performance of the epoxy coating. In addition, the antimicrobial mechanism of Ag nanoparticles played an important role in improving the anti-biofilm performance of these epoxy coatings.

• Journal of Pharmaceutical Investigation
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• v.17 no.1
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• pp.1-14
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• 1987

To increase the bioavailability of norfloxacin, inclusion complex of antimicrobial agent norfloxacin with ${\beta}-Cyclodextrin$ was prepared and studied by the solubility method, spectrophotometric methods(UV, IR, $^1H-NMR$), differential thermal analysis, powder X-ray diffractometry, the physical properties, the antimicrobial activity, DNA binding and in situ recirculation technique. The conclusions are summerized as following; 1) The inclusion complexation was identified by means of solubility, spectrophotometry(UV, IR, NMR), DTA and X-ray diffraction. 2) The molar ratio of $norfloxacin-{\beta}-cyclodextrin$ complex was 1 : 1. 3) The stability constant of $norfloxacin-{\beta}-cyclodextrin$ complex was $21.5\;M^{-1}$, and both true and apparent partition coefficients of the inclusion complex were larger than those of norfloxacin. 4) The time required to dissolve 60% $(T_{60}%)$ of the inclusion complex was 120 min. in distilled water and in the artificial intestinal juice, while norfloxacin did not reach to 60% dissolution within 120 min. 5) The antimicrobial activity of the inclusion complex against Pseudomonas aeruginosa, Klebsiella pneumoniae and Staphylococcus aureus showed no significant difference compared to that of norfloxacin alone. 6) Studies on binding properties between the inclusion complex and norfloxacin alone to DNA according to equilibrium dialysis showed no significant differency. 7) In situ absorption rates (Ka) of inclusion complex and norfloxacin alone were 0.229 and $0.102hr^{-1}$, respectively.

• YAKHAK HOEJI
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• v.33 no.3
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• pp.141-148
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• 1989

The weak UV absorbing antihistaminics such as chlorpheniramine, triprolidine, tripelennamine and diphenhydramine were analyzed by charge-transfer spectrophotometric method. The results obtained are summarized as folows. It was possible to determine a weak UV absorbing antihistaminics using the intense charge-transfer UV bands in chloroform. Charge transfer complexes were formed in a 1:1 ratio between antihistaminics and iodine in chloroform. Linear relationship was found between absorbance and concentration in the range of $1.0\;{\times}\;10^{-5}M-5.0\;{\times}\;10^{-5}M$ for chlorpheniramine( ${\varepsilon}\;=\;2.082\;{\times}\;10^4$) and tripelennamine ( ${\varepsilon}\;=\;1.578\;{\times}\;10^4$), $1.0\;{\times}\;10^{-5}M-8.0\;{\times}\;10^{-5}M$ for triprolidine ( ${\varepsilon}\;=\;1.120\;{\times}\;10^4$) and $1.0\;{\times}\;10^{-5}M-1.0\;{\times}\;10^{-4}M$ for diphenhydramine ( ${\varepsilon}\;=\;9.900\;{\times}\;10^3$). Charge transfer complexes of chlorpheniramine, triprolidine and tripelennamine have absorption maxima at 293 nm and complex form of diphenhydramine has absorption maximum at 270 nm. By UV, IR spectra, it could be inferred that CT-complexes were formed by interaction between the basic nitrogen of antihistaminics as electron donor (non bonding electron) and iodine as electron acceptor (${\sigma}$ bonding electron).

• Journal of the Korean Ceramic Society
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• v.54 no.6
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• pp.484-491
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• 2017

Chalcogenide glasses have been investigated in their thermodynamic, structural, and optical properties for application in various opto-electronic devices. In this study, the $Sb_{20}Se_{80-x}Ge_x$ with x = 10, 15, 20, and 25 were selected to investigate the glass stability according to germanium ratios. The thermal, structural, and optical properties of these glasses were measured by differential scanning calorimetry (DSC), X-ray diffraction (XRD), and UV-Vis-IR Spectrophotometry, respectively. The DSC results revealed that $Ge_{20}Sb_{20}Se_{60}$ composition showing the best glass stability theoretically results due to a lower glass transition activation energy of 230 kJ/mol and higher crystallization activation energy of 260 kJ/mol. The structural and optical analyses of annealed thin films were carried out. The XRD analysis reveals obvious results associated with glass stabilities. The values of slope U, derived from optical analysis, offered information on the atomic and electronic configuration in Urbach tails, associated with the glass stability.

• Polymer(Korea)
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• v.28 no.4
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• pp.352-359
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• 2004

Membrane technology was used for the optical resolution of the various racemic compounds such as tryptophan, tyrosine and phenylalanine, using enantioselective membranes prepared from sodium alginate (SA) and glutaraldehyde as a membrane material and crosslinking agent, respectively, The chemical structure of the membranes was characterized with FT-IR spectrophotometry and 3D molecular structure modeling study was done to figure out the optical resolution mechanism through the membrane. Effects of degree of crosslinking, feed concentration, operating pressure and different kinds of feed solution on the membrane performances were studied. As results, it was found that with increasing degree of crosslinking and membrane thickness, and decrease in the concentration of the feed solution and smaller size of solutes, the enantinselectivity of the membrane was improved. When the sodium alginate membranes with 80% of swelling index and 79${\mu}{\textrm}{m}$ of thickness were used, 77% of enantiomeric excess was obtained.

• Bulletin of the Korean Chemical Society
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• v.21 no.1
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• pp.101-104
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• 2000

Li-graphite intercalation compounds (GICs), synthesized at elevated temperature and pressure, were allowed to decompose spontaneously in the atmosphere. The decomposition processes were analyzed by of X-ray diffraction, DSC analysis, FT-IR measurements, UV/VIS spectrophotometry. The deintercalation reaction of the Li-GICs ceased after 6 weeks and only the residual compounds could be observed. A strong exothermic reaction was observed at 300 $^{\circ}C$ in thermal decomposition, and relatively stable decomposition curves were formed. A few endothermic curves have been observed at 1000 $^{\circ}C.$ After 6 weeks deintercalation reaction time of GICs, many exothermic and endothermic reactions were accompanied at the same time. In addition the reactions of the functional groups such as aromatic rings, nitrogen, $-CH_3$, $-CH_2$ etc. of GDIC obtained by the above reaction were confirmed by FT-IR spectrum. UV/VIS spectrophotometric measurement clearly shows the formation of a minimum energy value ($R_{min}$) for the compounds between Li-GICs as a starting material and Li-GDICs obtained until after 3 weeks of the deintercalation reaction, while they were no clear energy curves from 4 weeks of reaction time, because of the formation of the graphite structure, of high stages and of the Li compounds surrounding the graphite in the deintercalation reaction.