• Korean Journal of Veterinary Service
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• v.21 no.3
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• pp.261-266
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• 1998

A method for the determination of noboviocin in milk was presented by high performance liquid chromatography(HPLC). The novobiocin in the spiked sample was extracted with methanol and evaporated under vacuum. After evaporating, the residue was mixed with distilled water for 2$m\ell$, filtrates with 0.45$\mu\textrm{m}$ acrodisc was injected into HPLC. The results obtained were as follows ; 1. The calibration curve of novobiocin was showed constantly linear(r 0.999) in the range of 100~500ng/$m\ell$. 2. The mean recovery rate of novobiocin from the spiked milk sample were 88~98%. 3. The coefficients of variation were 2.6~5.8% 4. The lowest detectable limit of novobiocin was 25ppb.

• Journal of the Korean Society of Food Science and Nutrition
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• v.7 no.1
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• pp.1-6
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• 1978

Muscle fillets of flounder, Limanda herzensteini, were sliced into small pieces and dehydrated by the methods of sun drying, hot air drying and vacuum freeze drying, and evaluated for the protein quality by the method of shortened pepsin pancreatin digest residue (SPPDR) index which is the modified method of shortened pepsin digest residue index. In the analysis of the muscle protein hydrolysates, glutamic acid, aspartic acid and lysine comprised about 39% of the total amino acids of the protein. The content of pure protein in flounder muscle was 18.8%. The result of nutritional evaluation of the dried muscle protein by the computation of the SPPDR index showed that the freeze dried flounder muscle protein was superior in the nutritional efficiency to the others, sun dried. The freeze dried flounder muscle protein marked 89 of the SPPDR index number which is quite similar to the muscle protein of terrestrial animal in nutritional quality.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.128-128
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• 2012

We investigated the atomic and electronic properties of graphene grown by Pd silicidation and intercalation using LEED, STM, and ARPES. Pd was deposited on the 6H-SiC(0001) surface at RT. The formation of Pd silicide gives rise to breaking of Si-C bonds of the SiC crystal, which enables to release C atoms at low temperature. The C atoms are transformed into graphene from $860^{\circ}C$ according to the LEED patterns as a function of annealing temperature. Even though the graphene spots were observed in the LEED pattern and the Fourier transformed STM images after annealing at $870^{\circ}C$, the topography images showed various superstructures so that graphene is covered with Pd silicide residue. After annealing at $950^{\circ}C$, monolayer graphene was revealed at the surface. The growth of graphene is not limited by surface obstacles such as steps and defects. In addition, we observed that six protrusions consisting of the honeycomb network of graphene has same intensity meaning non-broken AB-symmetry of graphene. The ARPES results in the vicinity of K point showed the non-doped linear ${\pi}$ band structure indicating monolayer graphene decoupled from the SiC substrate electronically. Note that the charge neutrality of graphene grown by Pd silicidation and intercalation was sustained regardless of annealing temperature in contrast with quasi-free- standing graphene induced by H and Au intercalation. Further annealing above $1,000^{\circ}C$ accelerates sublimation of the Pd silicide layer underneath graphene. This results in appearance of the $(6r3x6r3)R30^{\circ}$ structure and dissolution of the ${\pi}$ bands for quasi-free-standing graphene.

• Journal of the Korean Vacuum Society
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• v.17 no.6
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• pp.544-548
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• 2008

At the semiconductor industry, Photoresist(PR) strip progress has high cost and time consuming process. Accordingly, many research group have been focused on the shortening of the PR strip progress. But the replacements of newly developed materials rather than normally used strip have accompanied by cost consumption. Therefore, we suggested the Plasma Liquid-Vapor Activation (PLVA) method of general PR strip solution for saving the PR strip time and the high strip rate of PR residue. The PLVA method was very effective for PR strip progress. Also, the ion damaged PR(high dose implanted photoresist: HDI-PR) was almost impossible to strip. However, it was very difficult to characterize the change of chemical composition of HDI-PR between with and without PLVA method. Thus, physical properties of HDI-PR surface with and without PLVA method were measured by using the nano-indenter system.

• Applied Chemistry for Engineering
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• v.27 no.4
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• pp.343-352
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• 2016

It has been estimated that the Earth has nearly 1.688 trillion barrels of crude oil, which will last 53.3 years at current extraction rates. The organization of petroleum exporting countries (OPEC) group forecasted that the oil prices will not jump to triple-digit territory within a decade, but it can quickly increase as the political issue for reducing oil production appears. With the potential of serious shortage of conventional hydrocarbon resources, the heavy oil, one of unconventional hydrocarbon resources including oil sand and natural bitumen has attracted worldwide interest. The heavy oil contains heavy hydrocarbon compounds, commonly called as resins and asphaltenes, with long carbon chains more than sixty carbon atoms. The high content of heavier fraction corresponds with the high molecular weight, viscosity, and boiling point. Physicochemical properties of residues from vacuum distillation of conventional oil, referred to as vacuum residues (VR) were similar to those of heavy oil. For the development of heavy oil reserves, reducing the heavy oil viscosity is the most important. In this article, commercially employed aquathermolysis processes and their application to VR upgrading are discussed. VR contains transition metals such as Ni and V, but these metals should be eliminated in advance for further refining. Recent studies on demetallization technologies for VR are also reviewed.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.4
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• pp.570-574
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• 2003

This study investigate the effects of starter cultures on the color stability of Chinese-style sausage. The samples were inoculated with $10^7cfu\;g^{-1}$ meat of either Staphylococcus carnosus or Staphylococcus xylosus. After mixing, curing at either $4^{\circ}C$ or $20^{\circ}C$ for 20 h and then drying at $50^{\circ}C$ for 5 h, the samples were then either vacuum packed or hung at $4^{\circ}C$ and $25^{\circ}C$ (85% R. H.). The pH, nitrite content, nitrosyl pigment content, metmyoglobin and L-, a-, b- values were measured. The pH value still remained above 6.0 during storage. Nitrite residue of all samples decreased after storage at $25^{\circ}C$ for 7 days. The samples inoculated with S. carnosus and S. xylosus had higher nitrite content (20.9-34.7 ppm) than the control (p<0.05). Samples inoculated with S. carnosus and S. xylosus had higher nitrosyl pigment content and lower metmyoglobin content than those of the control. The L- and b- values of all samples decreased but the a- values increased with storage time. The result suggested that S. carnosus and S. xylosus starter cultures be used to improve color stability of Chinese-style sausage.

• Journal of environmental and Sanitary engineering
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• v.15 no.1
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• pp.95-101
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• 2000

This study was investigated to the reaction of alumina sintering with alkaline. The soluble $NaAlO_2$ was made after the commercial ${\alpha}-Al_2O_3$ was calcinated with NaOH. The reaction of alumina was carried out to be based on the effects of calcination temperature, time, and the mixing ratio of ${\alpha}-Al_2O_3/NaOH$. The alumina was calcined over $500^{\circ}C$ with NaOH powder after it was sieved with 170/270 mesh. The calcined alumina with NaOH powder was dissolved into $25^{\circ}C$ distilled water and filtrated, and HCI was added to adapt pH 6.5~7.5. The residue was separated with vacuum pump for filtration after it was adapted to proper pH, and aluminum compound was precipitated with $Al(OH)_3$. The investigation was carried out with the variables; the calcination temperature($500-900^{\circ}C$), the calcination time (30~90 min), and the concentration of HCI when leaching(0.5~3.0N) respectively. In this investigation, the main product of ${\alpha}-Al_2O_3$ and NaOH was $NaAlO_2$ and the maximum conversion ratio was 91.4% under the optimum conditions as followed ; the ratio of NaOH/${\alpha}-Al_2O_3$ was 1.5 and the calcination conditions were $800^{\circ}C$ and 90 min.

• Advances in environmental research
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• v.2 no.1
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• pp.1-8
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• 2013

There is a significant demand to make various dissolved gases in water. However, the conventional aeration method shows low gas mass transfer rate and gas utilization efficiency. In this study, a novel rotating wheel entraining gas method was developed for making high dissolved $O_2$ and $O_3$ in water. It produced higher concentration and higher transfer rate of dissolved $O_2$ and $O_3$ than conventional bubble aeration method, especially almost 100% of gas transfer efficiency was achieved for $O_3$ in enclosed reactor. For application of rotating wheel entraining gas method, aerobic bio-reactor and membrane bio-reactor (MBR) were successfully used for treatment of domestic and pharmaceutical wastewater, respectively; and vacuum ultraviolet $(VUV)/UV+O_3/O_2$ reactors were well used for sterilization in air/water, removal of dust particles and toxic gases in air, and degradation of pesticide residue and sterilization on fruits and vegetables.

• Bulletin of the Korean Chemical Society
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• v.34 no.5
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• pp.1473-1476
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• 2013

Solution-based deposition of $CuIn_xGa_{1-x}Se_2$ (CIGSe) thin films is well known non-vacuum process for the fabrication of CIGSe solar cells. However, due to the usage of organic chemicals in the preparation of CIG precursor solutions, the crystallization of the polycrystalline CIGSe and the performance of CIGSe thin film solar cells were significantly affected by the carbon residues from the organic chemicals. In this work, we have tried to eliminate the carbon residues in the CIG precursor thin films efficiently by using soft-annealing process. By adjusting soft-annealing temperature, it is possible to control the amount of carbon residues in CIG precursor thin films. The reduction of the carbon residues in CIG precursors by high temperature soft-annealing improves the grain size and morphology of polycrystalline CIGSe thin films, which are also closely related with the electrical properties of CIGSe thin film solar cells.

• Applied Chemistry for Engineering
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• v.22 no.6
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• pp.664-671
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• 2011

The vacuum residue of petroleum refinery, i.e. asphalt, was modified through a non-catalytic air blowing process to prepare the semi-blown asphalt. Changes in composition, chemical structure, and physical properties of asphalt were examined. The result from the thin layer chromatography showed that the asphaltene content in asphalt was increased by the air blowing on account of the aromatization of aliphatic hydrocarbon and condensation. These changes in molecular structure were also confirmed by $^1H-NMR$, differential scanning calorimetry, and thermogravimetry. Because of the molecular structure changes, the penetration of asphalt was decreased and the softening point and the flash point of asphalt were increased.