• Applied Biological Chemistry
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• v.41 no.7
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• pp.516-521
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• 1998

Solubility patterns and gelatinization properties of two waxy rice starches, Sinsunchalbyeo and Hwasunchalbyeo, were investigated. Shapes of all starch granules were round and polygonal, and their X-ray diffraction patterns were all A type. Amylose content and water binding capacity of Sinsunchalbyeo were similar to those of Hwasunchalbyeo. The swelling powers and solubilities of two starches were increased with increasing temperature in range of $65{\sim}95^{\circ}C$, and those of Hwasunchalbyeo was higher. Iodine affinities of soluble fractions in Sinsunchalbyeo starch were higher than those in Hwasunchalbyeo at the same temperature and both were increased with increasing temperature. λmax of soluble fraction of Sinsunchalbyeo starch was highest at $75^{\circ}C$ of heating temperature. The transmittance of starch suspensions were increased rapidly at $60{\sim}65^{\circ}C$. By Rapid Visco Analyzer, initial gelatinization temperature of Sinsunchalbyeo was $67.2^{\circ}C$, and that of Hwasunchalbyeo was $68.2^{\circ}C$. In DSC analysis, onset temperature for gelatinization of Sinsunchalbyeo and Hwasunchalbyeo were $61.3^{\circ}C\;and\;62.9^{\circ}C$, respectively.

• Applied Biological Chemistry
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• v.26 no.2
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• pp.137-142
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• 1983

Starch granules of sweet potatoes, the Suwon 147 and the Chunmi were observed by photomicroscope and scanning electron microscope were round and polygonal. Granule sizes of the Suwon 147 and the Chunmi were $14{\sim}30{\mu}m,\;16{\sim}34{\mu}m$, respectively. X-ray diffraction pattern of starch granules resulted weak crystallinity at $2{\theta}$ 14.8, 17.2, 22.5. Starch granules were of the Ca crystalline type. The blue values of the Suwon 147 and the Chunmi were determined to be 0.342 and 0.279, amylose contents 27.6% and 23.6%, and water binding capacity 178.7% and 185.5%. Swelling of the starches negligible until $50^{\circ}C$ thereafter it increased rapidly. Swelling power of the Suwon 147 was more slightly than that of the Chunmi. Optical transmittance of 0.2% starch suspensions was increased rapidly from $65^{\circ}C$ and the gelatinization at $65{\sim}80^{\circ}C$ was of sing1e stage. Amylogram patterns of 4% starch solutions were similar to no peak viscosity. Viscosity of the Suwon 147 was increased, but that of the Chunmi was decreased at $92.5^{\circ}C$.

• Korean Journal of Soil Science and Fertilizer
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• v.6 no.4
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• pp.221-226
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• 1973

In order to investigate the silica effect of insufficient wollastonite to the official standard (above than 15% of suluble silica (N/2 HCl) on rice plant as silica fertilizer, 9 kinds of wollastonites and slag were adopted to examine the amount of silica absorbed by rice straw during growing period, and soluble silica of wollastonites extracted by 7 buffer solutions were compared with silica content in rice straw. Crystalls of ingredient in wollastonite ores were identified by X-ray diffractometer. The results were that silica content of rice plant at growing stages were increased as same ratio of soluble silica. content in wollastonite. Wollastonite containing more than 10% of souble silica (N/2 HCl) could be applied as fertilizer because absorbed amount of silica by rice plant from them are higher than from slag which contained 30% of soluble silica. Wollastonite powder mixed with impure ores in which soluble silica could not be extracted had the same effect on silica absorption of straw as wollastonite powder which contained conformable amount of soluble silica. The soluble silica of wollastonite extracted by buffer solutions (2% citric acid, N. NaOAc, N. $NH_4OAc$, Petermann solution, 0.1M. EDTA, and Hot water) had high significant relation to silica content in rice straw, but soluble silica extracted N/2 hydrochloric acid solutilon, also, had deep relation to them in rice straw. The adequate solution to extract silica from wollastonites is N/2 hydrochloric acid solution because its extracted silia amount is much higher than other solution (about one hundred times) and can be determined by gravimetric analysis. X-ray diffraction pattern would identify qualitatively purity of wollastonite, and large amount of soluble silica was extracted from wollastonite which was appeared to be weathered.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.13 no.3
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• pp.122-126
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• 2003

In this study, $Zn_{0.86}Mn_{0.14}$Te epilayer of 0.7 $\mu\textrm{m}$-thickness was grown on GaAs(100) substrate by using hot wallepitaxy. GaAs(100) substrate was removed from $Zn_{0.86}Mn_{0.14}$Teepilayer by the selective etching solution. The crystal structure and the lattice constant of only Z $n_{0.86}$ M $n_{0.14}$Te epilayer were investigated to be zincblende and 6.140 $\AA$ from X-ray diffraction pattern, respectively. Mn composition x of $Zn_{1-x}Mn_x$Te epilayer was found to be 0.14 using this lattice constant and Vegard's law. The crystal quality of the epilayer was confirmed to be very good due to 256 arcsec-full-width at half-maximum of the double crystal rocking curve. The absorption spectra from the transmission ones were obtained to measure the band gap energy of $Zn_{0.86}Mn_{0.14}$Te epilayer from 300 K to 10 K. With the decreasing temperature,. strong absorption regions in the absorption spectra were shifted to higher energy side and the absorption peak meaning the free exciton formation appeared near the absorption edge. The band gap energy values of $Zn_{0.86}Mn_{0.14}$Te epilayer at 0 K and 300 K were found to be almost 2.4947 eV and 2.330 eV from the temperature dependence of the free exciton peak position energy of $Zn_{0.86}Mn_{0.14}$Te epilayer, respectively. The free exciton peak position energy of $Zn_{0.86}Mn_{0.14}$Te epilayer without GaAs substrate was larger 15.4 meV than photoluminescence peak position energy at 10 K. This energy difference between two peaks was analysed to be Stokes shift.

• Economic and Environmental Geology
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• v.26 no.2
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• pp.129-134
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• 1993

At the Janggun mine, boulangerite usually occurs as needles or irregularly-shaped grains, up to $500{{\mu}m}$ in longer dimensions, closely associated with galena, minerals of a tetrahedrite-freibergite series and bournonite in the peripheries of South A and B orebodies and the zone of manganoan carbonates surrounding them. In some places, especially at the top of South B orebody, it occures as "feather ore" consisting of its fine needles or "hairs" in small drusy cavities together with fine-grained euhedral galena, pyrite, manganoan carbonates, quartz, etc. In reflected light, it is bluish grey in colour exhibiting moderate bireflectance and is strongly anisotropic without any internal reflections. Reflectance in air is $R_{max}=43.2$, $R_{min}=35.7$ percent at wavelength of 580 nm, and VHN: $146-173\;kg/mm^2$ at a 50 g-load. The chemical composition on the average from 23 complete spot analyses by electron microprobe is, Pb 56.1, Sb 25.1, S 18.5, Total 99.6 (all in weight percent); the corresponding chemical formula calculated on the basis of S=11 is; $Pb_{5.16}Sb_{3.93}S_{11.0}$ which fulfils approximately the ideal formula $Pb_5Sb_4S_{11}$. The strongest reflections on the X-ray diffraction pattern are; $3.73\;{\AA}\;(10)$, $3.22\;{\AA}\;(5)$, $3.03\;{\AA}\;(4)$ and $2.82\;{\AA}\;(5)$ and the pattern is in harmonic with space group $C^5_{2h}-P2_1/a$. From the textural evidence of the microscopic observations, the mineral is considered to have been formed at the latest stage of hydrothermal lead-zinc-silver mineralization.

• Korean Journal of Food Science and Technology
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• v.48 no.2
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• pp.165-171
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• 2016

Physicochemical properties of waxy maize flours prepared by hydrothermal and enzymatic treatments were evaluated. Waxy maize flours were hydrothermally treated using heat-moisture treatment (HMT) and annealing (ANN) and enzymatically treated using commercial enzymes (cellulase, proteinase, and pectinase). The HMT-modified waxy maize flours had low water absorption index (WAI), melting enthalpy, viscosity, and crystallinity. However, ANN-modified and enzymatically modified waxy maize flours had high WAI, melting enthalpy, and viscosity. X-ray diffraction analysis of ANN-modified and enzymatically modified waxy maize flours revealed a typical A-type pattern and displayed sharper crystalline peaks than those observed for the control groups (native waxy maize flours). In contrast, the crystallinity of HMT-modified waxy maize flours were decreased by hydrothermal treatment.

• 한국해양학회지
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• v.29 no.1
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• pp.17-27
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• 1994

The sediment collected from KODOS91-1 were studied using X-ray diffraction(SRD) analysis to clarify the composition and vertical distribution of clay minerals. Micropaleontological data(Radiolarians) was applied to identify the changes in post-depositional environment and chemical mechanism leading to the formation of authigenic minerals. The result show that the highest concentration of smectite is occurred in the lower part(Unit II, III) of sediment column and the lowest concentration in the upper part(Unit I) whereas terrestrial minerals, such as illite, kaolinite and quartz, indicate the opposite trends. Radiolarians in the upper part are composed entirely of Quaternary/Tertiary mixtures, whereas in lower sediment units generally revealed the middle Miocene to the Eocene. This may imply that the Quaternary and Tertiary sedimentary processes were continuously affected by reworking of older sediments and subsequent resegmentation. The changes of the sediment color, peak pattern of minerals and presence of reworked microfossils at the unit boundaries have been interpreted as evidence of authigenic formation. Mineralogical characteristics of the sediments in study area strongly indicates changes in paleoenvironments through geologic time, including changes in post-depositional conditions by physical processes and chemical mechanisms.

• Korean Journal of Materials Research
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• v.21 no.5
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• pp.250-254
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• 2011

We have synthesized bluish-green, highly-efficient $BaSi_2O_2N_2:Eu^{2+}$ and $(Ba,Sr)Si_2O_2N_2:Eu^{2+}$ phosphors through a conventional solid state reaction method using metal carbonate, $Si_3N_4$, and $Eu_2O_3$ as raw materials. The X-ray diffraction (XRD) pattern of these phosphors revealed that a $BaSi_2O_2N_2$ single phase was obtained. The excitation and emission spectra showed typical broadband excitation and emission resulting from the 5d to 4f transition of $Eu^{2+}$. These phosphors absorb blue light at around 450 nm and emit bluish-green luminescence, with a peak wavelength at around 495 nm. From the results of an experiment involving Eu concentration quenching, the relative PL intensity was reduced dramatically for Eu = 0.033. A small substitution of Sr in place of Ba increased the relative emission intensity of the phosphor. We prepared several white LEDs through a combination of $BaSi_2O_2N_2:Eu^{2+}$, YAG:$Ce^{3+}$, and silicone resin with a blue InGaN-based LED. In the case of only the YAG:$Ce^{3+}$-converted LED, the color rendering index was 73.4 and the efficiency was 127 lm/W. In contrast, in the YAG:$Ce^{3+}$ and $BaSi_2O_2N_2:Eu^{2+}$-converted LED, two distinct emission bands from InGaN (450 nm) and the two phosphors (475-750 nm) are observed, and combine to give a spectrum that appears white to the naked eye. The range of the color rendering index and the efficiency were 79.7-81.2 and 117-128 lm/W, respectively. The increased values of the color rendering index indicate that the two phosphor-converted LEDs have improved bluish-green emission compared to the YAG:Ce-converted LED. As such, the $BaSi_2O_2N_2:Eu^{2+}$ phosphor is applicable to white high-rendered LEDs for solid state lighting.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.5
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• pp.483-487
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• 2001

As a part of basic investigation for utilizing of cuttle bone as a calcium source, we examined on the extraction methods (calcining at $800^{\circ}C$ for 2 hrs, autoclaving at $121^{\circ}C$ for 10 hrs and ultrasonic treatments at $60^{\circ}C$ for 10 hrs) as a pretreatment methods for preparation of calcium-based powder from cuttle bone, The color of calcined calcium-based powder from cuttle bone was white, while that treated by other methods was light yellow. The calcium content in calcined calcium-based powder was $70.5\%$, and revealed high about 2 times compared to those pretreated by other methods. And, calcium solubility in calcined calcium-based powder was improved 22 times compared to raw cuttle bone powder, Among calcining, autoclaving and ultrasonic treatments as a pretreaoent methods for preparation of calcium-based powder from cuttle bone, calcining treatment was superior to other methods on the aspect of color, calcium solubility and purity of calcium-based powder, Judging from X-ray diffraction pattern of calcined calcium-based powder, most of calcium was present as a form of calcium oxide, But, pH of calcined calcium-based powder revealed strong alkali of pH 12.9. This pH value might invoke health risk in using food resource. Therefore, for utilization effectively calcined calcium-based powder from cuttle bone, it requires a suitable treatment such as adjustment of pH to neutral condition.

• Applied Biological Chemistry
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• v.26 no.4
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• pp.211-216
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• 1983

The physicochemical properties of starches isolated from three kinds of waxy ricer were investigated. The average diammeter of Orchal starch granule was 3.6u, and those of Hangang and Baegoon starch granules were 4.8u and 5.6u, respectively. X-ray diffraction patterns of all samples were A types. Optical transmittance of starch suspensions was increased rapidly $60{\sim}62^{\circ}C$, $50{\sim}55^{\circ}C$ and $50{\sim}60^{\circ}C$ in Olchal, Hangang and Baegoon, respectively, and all of them exhibited maximum transmittance $75{\sim}80^{\circ}C$ in range. Initial gelationization temperature by means of amylogram pattern was $60{\sim}61^{\circ}C$, then, Olchal starch had a little higher temperature than others. Raising power of them was $260\sim220$, and then, Olchal starch has a little higher raising power. But, water binding capacity of Baegoon and Hangang were somewhat higher than that of Olchal. Blue values of Olchal and Hangang were similar with 0.13, and that of Baegoon was 0. 14. Alkari numbers of Olchal, Hangang and Baegoon were 4.2, 4.9 and 5.1. The degree of retrogradation of Hangang and Baegoon starch gels were somewhat higher than that of Olchal starch gel.