• Bulletin of the Korean Chemical Society
• /
• v.33 no.6
• /
• pp.1867-1872
• /
• 2012

The 5-parameter Morse potential (5-MP) method for the interaction between O atom and Cr surfaces is constructed in the present work. The adsorption of O on Cr (100), (110), (111), and (211) surfaces are studied with 5-MP in detail. The fourfold hollow site of the Cr (100) surface is favored for O atom. On Cr (110), quasithreefold site is favored with the parallel frequencies (the frequencies of O atom paralleling the metal surface) of 342 and 538 $cm^{-1}$, and perpendicular frequency (the frequency of O atom perpendicular to the metal surface) at 526 $cm^{-1}$. On Cr (111), the most favored mode for O atom is found to be the quasi-threefold site with the perpendicular frequency at 553 $cm^{-1}$ and the parallel frequencies at 253 and 399 $cm^{-1}$. According to our calculation results, we speculate the most preferred mode for O adsorption on Cr (211) surface is the quasithreefold site with the perpendicular frequency at 583 $cm^{-1}$ and the parallel frequencies at 449 and 185 $cm^{-1}$.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.20 no.2
• /
• pp.183-190
• /
• 2002

This study is about the extraction of highway's superelevation using real time kinematic surveying among of GPS surveying methods which is economic method to construct data base in the side of highway maintain management. Using the developed vehicle, center line and shoulder of highway are measured and enough precision is obtained after analyzing the result. The result is show that 1.3 cm to 2.0 cm error in the clothed and about 0.8 cm to 1.2 cm error in the circular curve. Those errors are proved error to lane making during construction. This study is expected to become efficient method for extraction of highway alignment elements in the Mobile Mapping System.

• Korean Journal of Pharmacognosy
• /
• v.51 no.3
• /
• pp.217-221
• /
• 2020

Cirsium japonicum var. maackii (CM) has been used to treat certain medical conditions such as hemorrhage, hepatitis, and hypertension. Cirsimaritin was previously found as the major flavonoid in CM and is said to contribute to its pharmacological effects. There are currently no reports detailing the qualitative and quantitative detection of phytochemical indicators in the aerial parts of CM. Therefore, we developed a method to rapidly identify and quantify cirsimaritin in CM using HPLC/UV, and we optimized and validated this analytical method. The results showed good linearity in the concentration range tested (0.25-0.015 mg/mL, r² ≥ 0.9999), accuracy (93.9-111.3%), and precision (RSD ≤ 0.59%). The developed method can therefore be used for the rapid evaluation of cirsimaritin in CM.

• Korean Journal of Materials Research
• /
• v.4 no.4
• /
• pp.406-415
• /
• 1994

The effects of fabrication method and condition on critical current density of Ag sheathed Bi- 2223 superconducting tapes by powder-in-tube method were studied. The highest critical current density (Jc) in the whole process was measured in the repeative heat treatment of 250 hour and mechanical deformation of 2 times. These results are suggested that the high-Tc phase at the heat treatment of 250 hour was superior and the good grain alignment at the mechanical deformation of 2 times was analyzed by XRD pattern. The highest critical current density obtained by pressing method was $1.05\times 10^4A/\textrm{cm}^2$ and $0.78\times 10^4A/\textrm{cm}^2$ in case of rolling method. The multifilamentary wires with 7 and 49 filaments were fabricated to check the applicability of pressing and rolling method for preparing multifilaments wire. The critical current density of 7 filaments tapes prepared by pressing showed $0.45 \times 10^{4}A/\textrm{cm}^2$ and $0.20 \times 10^{4}A/\textrm{cm}^2$ for 49 filaments tapes prepared by rolling.

• Journal of Conservation Science
• /
• v.34 no.2
• /
• pp.97-106
• /
• 2018

The lime-soil mixture on barrier (LSMB) tomb is a representative type of tomb from the Joseon Dynasty. It is an important reference for understanding the society and funeral culture of that time. The LSMB excavated at the Gungri site were classified with manufacturing type. The ultrasonic velocity and rebound hardness method were used to estimate the physical properties of the LSMB. The strength values on the tomb of layered wall were different depend on measuring method. The compressive strengths of the tomb with layered wall, which is calculated by ultrasonic velocity and rebound hardness ranged from 4.0 to 355 (mean 43.6) $kgf/cm^2$ and 18.8 to 538 (mean 245.2) $kgf/cm^2$ ranges. The damage to the tomb with integrated wall during excavation and removal of the corpse could be a reason for the difference in results obtained using ultrasonic velocity method. Compressive strengths of tombs with integrated wall, which is calculated by ultrasonic velocity and rebound hardness ranged from 5.7 to 793 (mean 281.6) $kgf/cm^2$ and 4.5 to 550.5 (mean 172.4) $kgf/cm^2$ values. Physical properties on the tombs of integrated wall had different in compressive strength value but showed similar tendency. Thus, evaluation of the physical properties has shown that measuring ultrasonic velocity and rebound hardness methods are more effective in the LSMB with integrated walls. Further, the strength values obtained through the rebound hardness method are more constant than those obtained through the ultrasonic method due to the small detection area required by the former.

• Journal of the Korean Chemical Society
• /
• v.12 no.2
• /
• pp.47-50
• /
• 1968

Two methods for separation of the impurities from bismuth metal have been found by the use of Dowex $1{\times}4,$ anion exchange resins. The first method is that Dowex $1{\times}4$ resins are packed into the two stage columns (height of under stage is 22cm and upper stage is 3cm, and diameter of columns are 1.5cm), and the impurities of Pb(II), Ag(I) and Cu(II) are separated by the eluent of 7.5M HCl soln, Zn(II), Fe(III) by 0.5M HCl solns, and Te(IV) in the upper stage by 2M NaOH soln. Remained Au(III) in the upper stage is determined by the ignition with resins. The 2nd method is that for the separation of all the impurities simultaneously the same resins are packed into single stage column(height is 10cm and diameter is 1.5cm), and all the impurities of Pb(II), Zn(II), Cu(II), Fe(III) and Ag(I) are eluted by the eluent of 0.5M HCl soln. Separated impurities are determined by the colorimetry.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.32A no.7
• /
• pp.77-84
• /
• 1995

We studied the effects of the Zr/Ti ration and the bottom electrode (Pt or ITO) on the electrical properties of PZT thin films prepared by sol-gel method. Their permittivities and tagent losses with the variation of frequencies were measured by the LCR meter and their maximum polarizations, remanent polarizations, and coercive fields were obtained from the hysteresis loops measured by the Sawyer-Tower circuit. For the PZT thin film of the Zr/Ti ration of 53/47, permittivity at 10kHz, coercive field, maximum and remanent polarizations ere measured as 952, 20.7kV/cm, 10.43${\mu}C/cm^{2}$ and 4.3${\mu}C/cm^{2}$, respectively. For the film of the Zr/Ti ration of 25/75, coercive field, maximum and remanent polarizations were measured as 33.12kV/cm, 5.59${\mu}C/cm^{2}$ and 1.5${\mu}C/cm^{2}$, respectively. For the film of the Zr/Ti ratio of 75/25, they were measured as 23.8kV/cm, 7.45${\mu}C/cm^{2}$, and 3.5${\mu}C/cm^{2}$, repectively. Our investigation into the effects of the lower electrode on the electrical properties of PZT films showed the following results. The permittivities of the PZT films deposited on the ITO electrode decreased more quickly than those of the PZT films on the Pt electrode. The tangent losses of the former films increased more quickly than those of the latter. These may be due to the degradation of the quality of the interface between the electrode and the film, which results from the diffusion of Pb. It is also noticeable that permittivities and tangent losses of the PZT films deposited on the ITO electrode varied differently with the Zr/Ti ratio. This may indicate that the quality of the interface between the electrode and the film changes with the Zr/Ti ration of the PZT film.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.20 no.6
• /
• pp.1107-1115
• /
• 1996

An investigation made of the easing contraction ratio according to sewing condition (seam line; wp, wf, 45$^{\circ}$ bias, stitch density; 13 stitch/cm (0.8 mm), 9 stitch/cm (1.1 mm), 6.5 stitch/ cm (1.5 mm), 5 stitch/cm (2 mm), 4 stitch/cm (2.5 mm), thread; sp 60$^{\circ}$s/2, sp 60$^{\circ}$s/3, st 60$^{\circ}$s/3, st 50$^{\circ}$s/3)) by lockstitch industrial sewing machine with shirring foot. The correlations of the easing and sewing conditions were by SPSS PC), and visual test was done by enlarged photo. The results obstained were as follows:. 1. The easing contraction ratio is increased in proportion to the low of stitch density. 2. The easing contraction ratio of wp, 45$^{\circ}$ bias is correlated with stitch density, and that of wf be with stitch density, elongation & weight. 3. The easing contraction ratio of 13 stitch/cm (0.8 mm), 9 stitch/cm (1.1 mm), 6.5 stitch/ cm (1.5 mm), 5 stitch/cm (2.0 mm) is correlated with flexible rigidity, and that of 4 stitch/ cm (2.5 mm) be with flexible rigidity and crease-resistance. 4. As a results of SPSS PC+ statistics, the easing contraction ratio is statistically correlated to the seam line, stitch density, upper thread tension, and fabric characteristics. 5. As a results of visual test by the enlarged photo, the limit of stitch density for easing contraction was 5 stitch/cm (2.0 mm).

• Korean Journal of Environmental Agriculture
• /
• v.41 no.4
• /
• pp.230-235
• /
• 2022

BACKGROUND: Ammonia gas emitted from nitrogen fertilizers applied in agricultural land is an environmental pollutant that catalyzes the formation of fine particulate matter (PM2.5). A significant portion (12-18%) of nitrogen fertilizer input for crop cultivation is emitted to the atmosphere as ammonia gas, a loss form of nitrogen fertilizer in agricultural land. The widely practiced method for fertilizer use in agricultural fields involves spraying the fertilizers on the surface of farmlands and mixing those with the soils through such means as rotary work. To test the potential reduction of ammonia emission by nitrogen fertilizers from the soil surface, we have added N, P, and K at 2 g each to the glass greenhouse soil, and the ammonia emission was analyzed. METHODS AND RESULTS: The treatment consisted of non-fertilization, surface spray (conventional fertilization), and soil depth spray at 10, 15, 20, 25, and 30 cm. Ammonia was collected using a self-manufactured vertical wind tunnel chamber, and it was quantified by the indophenol-blue method. As a result of analyzing ammonia emission after fertilizer treatments by soil depth, ammonia was emitted by the surface spray treatment immediately after spraying the fertilizer in the paddy soil, with no ammonia emission occurring at a soil depth of 10 cm to 30 cm. In the upland soil, ammonia was emitted by the surface spray treatment after 2 days of treatment, and there was no ammonia emission at a soil depth of 15 cm to 30 cm. Lettuce and Chinese cabbage treated with fertilizer at depths of 20 cm and 30 cm showed increases of fresh weight and nutrient and potassium contents. CONCLUSION(S): In conclusion, rather than the current fertilization method of spraying and mixing the fertilizers on the soil surface, deep placement of the nitrogen fertilizer in the soil at 10 cm or more in paddy fields and 15 cm or more in upland fields was considered as a better fertilization method to reduce ammonia emission.

• Analytical Science and Technology
• /
• v.32 no.4
• /
• pp.139-146
• /
• 2019

A simple and reliable analytical method based on high-performance liquid chromatography-ultraviolet detection was established for the analysis of the flowers of Chrysanthemum morifolium (CM). Luteolin-7-O-glucoside (LU7G) was chosen as a target analyte considering its content, availability, and ease of analysis. Chromatographic separation of LU7G was achieved using a Phenomenex Gemini $C_{18}$ column ($250{\times}4.6mm$, $5{\mu}m$) run with a mobile phase consisting of 0.5 % acetic acid in water and 0.5 % acetic acid in acetonitrile at a flow rate of $1.0mL\;min^{-1}$. The detection wavelength and column temperature were set at 350 nm and $40^{\circ}C$, respectively. Method validation was performed according to the AOAC guidelines and the method was specific, linear ($R^2=0.9991$ for $50-300{\mu}g\;mL^{-1}$), precise (${\leq}3.91%$RSD), and accurate (100.1-105.7 %). The limits of detection and quantification were 3.62 and $10.96{\mu}g\;mL^{-1}$, respectively. The established method was successfully applied to determine the contents of LU7G in various batches of bulk CM extracts and labscale CM extract. The developed method is a readily applicable method for the quality assessment of CM and its related products.