• Natural Product Sciences
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• v.21 no.1
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• pp.14-19
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• 2015

Several $19{\alpha}$-hydroxyursane-type triterpenoids and hydrolysable tannins have beneficial effects on human health. Rubus crataegifolius (Rosaceae) has the cleft simple leaf whereas R. parvifolius has pinnate compound leaves. This research was aimed to find the variation in the contents of the triterpenoids and tannins between the infected versus uninfected leaves of R. coreanus and R. parvifolius and between young versus mature leaves. Triterpenoids and tannins were quantitatively analyzed by HPLC. Six triterpenoids including tormentic acid, euscaphic acid, 23-hydroxytormentic acid, coreanoside $F_1$, kaji-ichigoside $F_1$ and niga-ichigoside $F_1$ were used for standard compounds. Gallotannins and ellagitannins were quantitatively evaluated using the indicatives of methyl gallate and ellagic acid. The infected leaves of R. crataegifolius contained higher levels of triterpenoids and tannin than the uninfected leaves; however, lower quantity of total tannin was observed in the mature leaves than in the young leaves. Although the pinnate compound leaves of R. parvifolius exhibited similar tendency of those compositional variation with R. crataegifolius each other, its contents of triterpenoids do not considerably vary. Variation of the contents of triterpenoids and tannins were particularly distinct in R. crataegifolius by growth and infection.

• Tribology and Lubricants
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• v.11 no.5
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• pp.40-46
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• 1995

This study concerns the design and development of the non-vibrating capacitance probe which could be used as a non-contact sensor for tribological wear. This device detects surface charge through temporal variation in the work function of a material. Experiments are performed to demonstrate the operation of the probe on a roating aluminum shaft. The reference electrode of the probe, made of lead, is placed adjacent (< 1.25-mm distance) to the shaft. Both surfaces which are electrically connected, form a capacitor. An artificial spatial variation in the work function is imposed on the shaft surface by coating a segment along the shaft circumference with a colloidal silver paint. As the shaft rotates, the reference electode senses changing contact potential difference with the shaft surface, owing to compositional variation. Temporal variation in the contact potential difference induces a current through the electrical connection. This current is amplified and converted to a voltage signal by an electoronic circuit with an operational amplifier. The magnitude of the signal decreases asymptotically with the electrode-shaft distance and increases linearly with the rotational frequency. These results are consistent with the theoretical model. Potential applications of the probe on wear monitoring are proposed.

• Journal of the Korean institute of surface engineering
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• v.31 no.2
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• pp.81-90
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• 1998

NiCrAly/YSZ(8wt% Y2O3-Zro2) functionally fraded thermal barrier coating (FGC) layers on a Co-base sureralloy (HAYNESS 188) substrate were fabricated using Ar shielded single torch air plasma spraying method. Functional grading were produced with the stepwise compositional change throughout layer thinkness. Microstructural observation revealed a sucessful fabrication of NiCrAly/YSZ FGC. From the results of the curvature measurement, adhesive stength measurement and thermal shock test for the FGC, it was concluded that the optimum enhance of functionally graded coating layer thinkcess and compositional pattern exit to enhance the properties of FGC, which is closely reated to the internal residual distribution with it.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.5
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• pp.627-639
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• 1998

A combustion model for the incineration of municipal solid waste(MSW) in the stoker type incinerator was developed by considering the variation of physical composition of MSW. Theoretical analysis and numerical simulation for the combustion characteristics in incinerator were conducted by using the present model and the effects of compositional variation on the incineration characteristics of MSW was examined theoretically. It is found that large excess air enhances drying, but depresses volatilization. For the large value of moisture content, pyrolysis is fast but drying is slow. As the value of plastic content increases, devolatilization becomes slower. Larger amount of primary air supply to the rear side of stoker leads to increase the possibility of delaying the combustion.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.436-438
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• 2009

To evaluate short rotation forestry candidates, seven clones of Salix hultenii were investigated as focused on chemical compositions and energy contents. There were significant variations in chemical compositions and energy contents among different clones. Variations in hot-water extractives content were 6.6-16.0% and 19.6-25.4% variation in lignin content. In carbohydrate compositional analysis, xylan contents were 7.5-13.1% with variation among different clones. Higher heating values were 17.69-20.02 MJ/kg.

• Journal of the Mineralogical Society of Korea
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• v.6 no.2
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• pp.94-104
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• 1993

The compositional variation of electrums from gold-silver and antimony deposits in the Dunjeon Baegjeon mining area, range from 22.6 to 69.5 atom% of Ag. Ag contents in electrums vary with paragenetic sequences and associated minerals. Ag contents increase from core to margin in a single grain. Compositional range of electrums from the North ore deposits of the Dunjeon gold mine are from 22.6 to 29.5 atom% of Ag. Electrums contain Cu(0.40 to 0.55 atom%) and Bi(0.35 to 0.67 atom%). Composition of electrums from the South ore deposits of the Dunjeon gold mine vasies from 33.6 to 69.5 atom% of Ag. Cu and As contents in electrums range from 0.20 to 1.92 and from 0.70 to 1.90 atom%, respectively. As the content of Ag in electrums increase, the contents of Bi and As in electrums increase but that of Cu decrease. Electrums of the Baegjeon gold deposits contain 35.6 to 63.5 atom% of Ag, suggesting that Au contents in electrums associated with base metal sulfied be higher than those associate with Ag-minerals. Ag/Au rations in electrums increase with decreasing temperature, salinity and $fs_2$ of the mineralizing solution.

• The Journal of the Petrological Society of Korea
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• v.12 no.3
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• pp.110-118
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• 2003

Olivine from the Layered Series (LS), Upper Border Series (UBS), and Marginal Border Series (MBS) of the Skaergaard intrusion was analyzed to examine compositional variation. In general, olivine from all three series shows similar trends in major elements with differentiation: FeO＊ (total iron as FeO＊), Ti $O_2$, and MnO in the olivine, progressively increase, MgO and $SiO_2$progressively decrease, and Na$_2$O, K$_2$O, A1$_2$ $O_3$, CaO, and P$_2$O$\_$5/ remain unchanged at low abundances. No abrupt changes in the trends of major components in Skaergaard olivine are observed. The systematic compositional variations in Skaergaard olivine during differentiation preclude the possibility of any injection of new magma into the chamber during differentiation. Abrupt change in MnO, however, is observed in Skaergaard olivine during differentiation. MnO in Skaergaard olivine steadily increases with differentiation from LZ to UZc and then decreases in UZc of the LS and its equivalents of the MBS and UBS. The decrease of MnO in Skaergaard olivine during the final stage of differentiation is attributable to the abrupt and extensive appearance of ferrobustamite as a liquidus phase.

• The Journal of the Petrological Society of Korea
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• v.14 no.1
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• pp.12-23
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• 2005

Cretaceous granitic rocks in the Waryongsan area occur as a stock and show compositional changes with altitude. They include mafic microgranular enclaves (MME) with various sizes and types. The MMEs present clear evidence of magma mingling such as supercooling zone, mantling texture and back veining. The granitic rocks are divided into porphyritic granite, porphyritic granodiorite and fined-grained granite by their petrographic characteristics and modal compositions. The MMEs are discriminated to quartzdioritie, quartzmonzodiorite and tonalite. They have varying areal proportions in each granitic rock-type: 10∼l5% in the porphyritic granite, about 50% in the porphyritic granodiorite, and about 20% in the fined-grained granite. SiO₂ contents shows compositional change of 61.2∼72.0wt.%. Mean SiO₂ contents have 61.7wt.% in the porphyritic granodiorite, 68.6wt.% in the porphyritic granite. and 71.9wt.% in the fined-grained granite, respectively. Major oxide contents of the granitic rocks linearly vary with SiO₂ contents from the porphyiritic granodiorite to the fine-grained granite on Harker diagrams. Linear compositional variations seem to have been caused by differential degrees of mingling between mafic magma and host granite. Where larger amount of mafic magma was injected into the host granitic magma, the two magmas reached to thermal equilibrium more quickly and eventually chemical mixing occurred to produce the composition of the porphyritic granodiorite. On the other hand. less amount of injected mafic magma would have been responsible for mechanical mixing to produce the compositions of the porphyritic granite and the fined-grained granite. Therefore, it is considered that the granitic rocks in the Waryongsan area experienced magmas mingling resulting from the injection of more mafic magma into differentiating granitic magma, and that the compositional changes of the granitic rocks were ascribed to the degree of mingling between the two magmas.

• Journal of the Korean Ceramic Society
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• v.28 no.12
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• pp.969-974
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• 1991

The influences of A(Cu1/3Nb2/3)O3(A=Pb, Ba and Sr) on the ferroelectric-paraelectric phase transition of BaTiO3 ceramics has been investigated. The tetragonality of crystal structure decreased with increasing A(Cu1/3Nb2/3)O3 content at room temperature. A linear correlation between Curie point and the tetragonality of lattice was not observed. In all three systems the variation of Curie point with the mole fraction showed similar tendency that the Curie point decreased at lower mole fraction but gradually increased in the region of higher mole fractions, Diffuse phase transitions were observed at higher mole fractions. The variation of Curie points could be explained by internal stress and Jahn-Teller distortion of BO6 due to Cu2+, and it was thought that the diffuse character of phase transition was caused by compositional fluctuation.

• The Research Journal of the Costume Culture
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• v.18 no.4
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• pp.731-740
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• 2010

This study attempted to understand the value of traditional floral wall patterns reflecting the distinct aesthetic consciousness of Korean people and reinterpret the images of floral wall patterns in simplified forms. In addition, the study created new floral patterns to apply them to the design of neckties and scarves. In a methodological aspect, the computer design software programs Adobe Illustrator CS2 and Adobe Photoshop CS2 were used to make the traditional floral wall patterns motifs. Four basic motifs for a new formative image were set using graphical functions such as omitting, simplifying, overlapping, repeating, and/or reducing shapes based on floral wall patterns, and each motif was developed in two variations with different colors applied to them. Each of the set motifs was expressed in a repeated arrangement and in a modified pattern of 45 degrees. Necktie design with a floral wall pattern made use of the motifs developed through a variety of effects such as simplification, repetition, size variation, and gradation and the pattern modified at a $45^{\circ}$ for application. Scarf design employed and applied the existing motifs in an appropriate manner for design purposes and reconstructed and expressed them through such effects as repetition, rotation, compositional variation and gradation.