• Food Science and Biotechnology
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• 제15권6호
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• pp.838-843
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• 2006

The chemical processes involved in the formation of green pigment in crushed garlic cloves were investigated based on the principle of pink pigmentation in macerated onions. Intact greening and non-greening garlic cloves were either left untreated or heated at $90^{\circ}C$ for 3 min to inactivate enzyme activities. First, a colorless ether soluble compound referred to as color developer reacted with glycine (among all free amino acids) in garlic to form a second compound insoluble in ether. The latter compound then reacted with formaldehyde to yield the green colored pigment. Alliinase activity was necessary for the production of color developer and for the development of green pigment. In greening garlic that had been heat treated, green pigmentation did not proceed due to the heat-inactivation of alliinase, but the addition of alliinase solution into the garlic homogenates restored the pigmentation. However, this phenomenon was not observed in non-greening garlic with or without heat treatment. Finally, the mechanism of green pigment formation in crushed garlicis similar to that of pink pigment formation in macerated onions.

• Bulletin of the Korean Chemical Society
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• 제27권8호
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• pp.1140-1144
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• 2006

A macrocyclic ligand, N,N',N'-tribenzyl-2,11,20-triaza[3,3,3](2,6)pyridinophane (BAPP), was used to prepare an iron(II) complex as a nonheme model complex, $[(BAPP)Fe]^{+2}$ (1). X-ray crystallography of a colorless crystal of 1 revealed that BAPP acted as a pentadentate ligand due to geometrical strain for the formation of a six-coordinate iron(II) complex by BAPP. As a result, the iron center revealed a significantly distorted square pyramidal geometry similar to that found in the active site of taurine dioxygenase (tauD). In the reaction of 1 with PhIO, no intermediate was observed in the UV-visible region of spectrometer at low temperatures. Catalytic oxidations of triphenyl phosphine with PhIO at ${-40^{\circ}C}$ revealed that 1 was able to convert triphenyl phosphine to triphenyl phosphine oxide.23; SSOCHKThioanisole was also oxidized to the corresponding methylphenyl sulfoxide under the same conditions.

• 품질경영학회지
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• 제16권1호
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• pp.1-7
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• 1988

The most important element upon the quality of family glass products is the color of glass, which is the first object of consumers concern in purchasing. Therefore, colorless and transparent color tone can level up the additional value of the products. But we have produced the glass products in a large quantity by using the automatic tank brazier, chronic problem has been left over the color tone. By compounding and analizing the management techniques applied by peculiar technique and design of experiments pertinently, and by adjusting the decoloring composition ratio, we can contribute to improvement of color tone as well as to the cost reduction by diminishing the unnecessary decoloring agent. Intangible effect was the securing the superiority of quality home and abroad with the improvement of color tone and was taking a triangular position the factors influencing the glass decoloring which had been an unexhausted field. Tangible effect was the reduction of decoloring cost by diminishing the unnecessary oxidant. We registered the optimal composition ratio condition which was searched by applicating the design of experiments. To maintain good color tone, we manage the degree of purity, the most important thing among the items of color tone, continuously by control chart and it has maintained steady state now.

• 한국지하수토양환경학회지:지하수토양환경
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• 제21권3호
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• pp.1-5
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• 2016

Rhodamine B Hydrazide as a novel fluorescent and colorimetric probe exhibiting remarkably selective fluorescence enhancement toward Hg²⁺ ion over other 16 metal ions is herein introduced. The probe reacts with Hg²⁺ ion followed by its spirolactam ring-opening to give a remarkable enhancement of absorption maximum at 550 nm as well as an enhanced fluorescence intensity at 580 nm in aqueous media. Upon titration with Hg²⁺ ion in various concentration of 10~200 uM, we found that the probe shows a marked color change from colorless to pink, enabling naked-eye detection toward mercury ion. In addition, in the presence of Hg²⁺ ion, the probe gave rise to change from non-florescence to strong orange fluorescence (Off-On) with a good linearity of R²=0.97. This preliminary results demonstrate that the fluorescent chemosensor we herein introduced can open a new strategy for marked selective and sensitive detection of mercury ions in contaminated soil containing various metal ions.

• 대한임상검사과학회지
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• 제45권1호
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• pp.1-4
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• 2013

Vancomycin-resistant enterococci (VRE) have emerged as important healthcare-associated infection since last two decades. ChromID VRE agar (cIDVA) is useful for VRE rectal swab screening. We investigated all VRE were isolated on the cIDVA. A total of 363 rectal swabs of 85 patients to test VRE screening were inoculated into bile-esculin (B-E) broth with $6{\mu}g/mL$ vancomycin. After 24 hours incubation, we subcultured B-E broths were changed to black onto cIDVA. All isolates were identified by the MICROSCAN and VITEK2. The vanA gene and vancomycin minimal inhibition concentration (MIC) were detected by PCR and E-test respectively. 277 E. faecium (84.7%), 16 E. faecalis (4.9%), 25 E. avium (7.6%), 8 E. gallinarum (2.4%) and 1 E. raffinosus (0.3%) were isolated. 10.3% of VRE detected on cIDVA were other than E. faecium and E. faecalis that presented various color from colorless to pale violet. All isolates contained vanA and vancomycin MIC were > $256{\mu}g/mL$. VRE isolates other than E. faecium and E. faecalis should be objective to the contact precautions for healthcare-associated infection control if they possess vanA gene. Due to emerging enterococci carrying vanA such as E. avium, E. gallinarum, and E. raffinosus, VRE surveillance should be expanded to all isolates on chromogenic agar.

• 한국지구과학회지
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• 제23권1호
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• pp.52-58
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• 2002

A colorless and transparent zirconium oxide ($Zr_{0.73}Y_{0.27}O_{1.87}$) crystal has been synthesized by the Bridgman-Stockbager method. The gem-quality material is produced by adding 20${\sim}$25 wt.% $Y_2O_3$ (stabilizer) and 0.04 wt.% $Nd_2O_3$ (decolorising agent) to the $ZrO_2$ powder. It shows a vitreous luster with a slight oily appearance. Under a polarizing microscope, it shows isotropic nature with no appreciable anisotropism. Mohs hardness value and specific gravity is measured to be 8${\sim}$$8{\frac{1}{2}}$ and 5.85, respectively. Under ultraviolet light it shows a faint white glow. The crystal structure of yttria-stabilized zirconia with 0.27 at.% Y has been re-investigated, using single crystal X-ray diffraction, and confirmed to be a cubic symmetry, space group $Fm{\overline{3}}m$ ($O^5_h$) with a=5.1552(5) ${{\AA}}$, V=136.99(5) ${{\AA}}^3$, Z=4. The stabilizer atoms randomly occupy the zirconium sites and there are displacements of oxygen atoms with amplitudes of ${\Delta}/a{\sim}$0.033 and 0.11 along <110> and <111> from the ideal positions of the fluorite structure, respectively.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2001년도 봄 학술발표회 논문집
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• pp.65-72
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• 2001

Since Pyoungtaek thermal power plant began using natural gas in 1986, the annual using volume has rapidly increased and reached 12.7 million tons in 1999. When the natural gas is cooled to a temperature of approximately -162$^{\circ}$C at atmospheric pressure, it condenses to a liquid called liquefied natural gas(LNG). LNG has a special characters such as odorless, colorless, non-corrosive, and non-toxic. So, LNG storage tank, tanker ship, transfer pipelines are required the special storage and transportation systems and technology. The presently operating LNG terminals are Pyongtaek and Inchon terminals. A total of 19 above-ground LNG storage tanks(100 thousand ㎘ grade) are currently in operation with a sendout capacity of 4,360tons/hour. To meet the growing domestic demand of LNG supply, the Inchon receiving terminal is expanding(six in-ground tank) and constructing a third LNG terminal at Tongyong. In this paper, case study on seepage analysis and countermeasure against increasing the seepage volume of in-ground LNG storage tank excavation work is reported. The results of an additional seepage analysis are presented to verify the design seepage volume of assumption section and seepage volume after curtain-grouting in the slurry wall.

• ALGAE
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• 제25권1호
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• pp.37-44
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• 2010

A tide-simulating apparatus was developed for culturing marine macroalgae. The objective of this study was to introduce a novel tide-simulating apparatus that can simulate a diurnal or semi-diurnal tidal cycle in the laboratory. In this apparatus, the seaweeds are move up and down and the water level remains the same during the simulated tidal cycle. The apparatus consists of 18 cylindrical culture tanks (3 blocks $\times$ 6 culture tanks) with 12 cm diameter and 24.5 cm long containing up to 2.5 L of seawater. There is a horizontal plate which covered all 18 culture tanks, and it is raised and lowered by a programmable motor that can regulate exposure time. In one application, seaweeds are attached to braided twine hung on Plexiglas air-tubing. The air-tubing is attached to a lid that is set on a horizontal plate. This apparatus is made of colorless Plexiglas to maximize light transmittance. This apparatus is easily disassembled and transportable to any indoor laboratory, wet laboratory, greenhouse, etc. This apparatus also offers considerable flexibility in terms of design. The size of culture tank can be redesigned by either increasing the height of cylinder or/and using a different diameter of cylindrical Plexiglas, therefore, larger/taller thalli can be cultivated. Growth rates of three eulittoral Porphyra species from different tidal elevations have been compared using this device.

• KSBB Journal
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• 제27권6호
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• pp.341-346
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• 2012

Indican (indoxyl-${\beta}$-D-glucoside) is a colorless natural compound and can be used as a precursor for the production of indigo. This production step only require an enzyme, ${\beta}$-glucosidase, that readily screened from microbial resource by using selective media supplemented with indican as a sole carbon source. Agrobacterium tumefaciens was well grown in this media and thus presumed to produce a related enzyme. The corresponding gene, encoding a protein with a calculated molecular mass of 51 kDa, was cloned and overexpressed as MBP fusion proteins. The purified enzyme was determined to be a dimer and showed the maximum activity for indican at pH 7.0 and $40^{\circ}C$. The kinetic parameters for indican, Km and Vmax, were determined to be 1.4 mM and 373.8 ${\mu}M/min/mg$, respectively. The conversion yield of indican into indigo using this enzyme was about 1.7-1.8 folds higher than that of previously isolated enzyme from Sinorhizobium meliloti. Additionally, this enzyme was able to hydrolyze various ${\beta}$-1,4 glycoside substrates.

• Journal of Microbiology and Biotechnology
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• 제28권10호
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• pp.1691-1699
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• 2018

A metabolically-engineered Deinococcus radiodurans R1 strain capable of producing phytoene, a colorless $C_{40}$ carotenoid and a promising antioxidant, has been developed. To make this base strain, first, the crtI gene encoding phytoene desaturase was deleted to block the conversion of phytoene to other carotenoids such as lycopene and ${\gamma}$-carotene. This engineered strain produced $0.413{\pm}0.023mg/l$ of phytoene from 10 g/l of fructose. Further enhanced production of phytoene up to $4.46{\pm}0.19mg/l$ was achieved by overexpressing the crtB gene encoding phytoene synthase and the dxs genes encoding 1-deoxy-$\text\tiny{D}$-xylulose-5-phosphate synthase gene, and by deleting the crtD gene. High cell-density culture of our final engineered strain allowed production of $10.3{\pm}0.85mg/l$ of phytoene with the yield and productivity of $1.04{\pm}0.05mg/g$ and $0.143{\pm}0.012mg/l/h$, respectively, from 10 g/l of fructose. Furthermore, the antioxidant potential of phytoene produced by the final engineered strain was confirmed by in vitro DPPH radical-scavenging assay.