• Journal of Powder Materials
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• v.2 no.2
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• pp.135-141
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• 1995

As the first step of study on fabrication of ceramic powders from phytoliths in rice, especially in rice husks, pulverization method of rice husks and the properties of milled rice husks were investigated. Impact methods, such as ball milling, were not meaningful for pulverizing elastic and thin fabric structure of rice husks. The most effective one was cutting method. In the present work, a rotating knife cutting method was applied to pulverizing rice husks. A 40-mesh screen was inserted under the rotating knives. The most portion of the milled powder was found in -50/+100 mesh section. Morphology of the milled rice husks revealed that the husks larger than 70 mesh were flake-like shape, at -70/+100 mesh section relatively equi-axed shape, at -170/+325 mesh section rod-like shape, and below 325 mesh section dust-like shape. Tap density of raw rice husks was about 0.1 $g/cm^3$, while those of milled rice husks were over $0.4 g/cm^3$. This meant that, for a given volume of reactor, raw material charge can be increased more that 4 times when using milled rice husks than unmilled one. True densities of unmilled and milled rice husks were higher than $1.4 g/cm^3$, and increased with decreasing milled sizes.

• Textile Coloration and Finishing
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• v.22 no.2
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• pp.132-139
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• 2010

Sericin pulverization process was applied by freezing-thawing of sericin protein concentration solution and physicochemical properties of sericin/chitosan blended films were investigated. In sericin pulverization process by freezing-thawing method, the refrigeration storage at $4^{\circ}C$ maximized gelling between sericin molecules, which increased 10% of recovery ratio from sericin concentration solution that using ultrafiltration procedure. In physicochemical properties of sericin/chitosan blended films, the maximum load of chitosan (6.7kgf) had higher than that of sericin (1.2kgf), and the elongation of sericin and chitosan had 96% and 34%, respectively. Also FT-IR analysis of sericin/chitosan blended films showed that both sericin and chitosan films had amide I peak (N-H bond) in $1,521cm^{-1}$ and amide II peak (C=O bond) in $1,630cm^{-1}$. In addition, it could confirm compatibility between both materials as indicated by the decrease in the amide I peak's absorption value as chitosan content increases.

• Journal of the Korean Society of Radiology
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• v.4 no.1
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• pp.11-17
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• 2010

A urolithiasis, also called calculus, is one of the brutal illnesses, which has constantly harassed humanbeings from time immemorial. However, there is no appropriate method of prevention so far. So, Urological therapy must be followed upon those patients. The biggest problem of urolithiasis is usually causing harsh pain, fever, and throw up. The pain would be more intensified when something came through the ureter or the moment of convulsion caused beyond transmission of urinary calculus. Even strong painkillers, such as fentanyl and Pethidine, can not handle those harshly pain easily. Therefore, a prompt action of medical check up and its therapy must be required to those patients. This thesis paper has put the accent on the specific therapy, known as ESWL (Extracorpereal Shock Wave Lithotripsy), which have generated quite optimum resolution to patients, who received harsh pain from Proximal ureteral stone and Mid ureteral stone and because of its low provability of pulverization. The results of the experiment confirmed that the stone, located between Proximal and Mid ureter, has lower provability of pulverization than distal ureter, because its accuracy rate on shock wave, in respect of breathing, are low. However, decrease in discharge interval have enhanced provability of pulverization. it can also intensify probability of pulverization and its safety by discharging high power with appropriate intervals, and that is more efficient than discharging low power with frequent time.

• Proceedings of the Korean Magnestics Society Conference
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• 2000.09a
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• pp.393-394
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• 2000

The magnetic alloy of $Nd_{2}Fe_{14}B$-type was synthesized by a mechano-chemical method, including the processes of spray-drying, de-binding, milling, $H_{2}$- and Ca-reduction and washing. The very fine $Nd_{2}Fe_{14}B$ particles smaller than $1\mu\textrm{m}$ could be achieved without the inevitable pulverization step in conventional processes.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.525-528
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• 2008

This study is performed to know influence on the hydration according to alkali activator and method of pulverization and fineness in slag-cement. The compressive strength of mortar were examined when the SG powder of which the specific surface area are 4,000, 6,000, and 8000cm$^2$/g were substituted for 50wt.% of ordinary portland cement. Na$_2$SO$_4$, Ca(OH)$_2$, NaOH were used as alkali activator. respectively, As the results, the compressive strength of mortar increased as following the order, Na$_2$SO$_4$>Ca(OH)$_2$>None>NaOH until 7days. But at 28days, mortar used Ca(OH)$_2$ as alkali activator were the highest strength.

• ALGAE
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• v.19 no.2
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• pp.123-127
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• 2004

A more rapid and efficient method to extract RNA from Ecklonia cava Kjellman (Laminariales, Phaeophyceae) was introduced in this study. Each step of the procedure was evaluated and the optimal concentration of each chemical in the lysis solution was determined. Tissue pulverization with PVPP and β-mercaptoethanol in the lysis solution were not essential for RNA extraction of this species. The highest yield and purity of E. cava RNA were obtained by the lysis solution containing 1% CTAB, 1 M NaCl, 0.7% PVP, 10mM EDTA and 100mM Tris-Cl (pH 9.0). Approximately 8μg of RNA was obtained from 200 mg of ground tissue. The ratios of the absorbance at 260 nm and 280 nm were from 1.6 to 1.8 and those of at 230 nm and 260 nm were from 1.8 to 2.0. The extracted RNAs obtained in this study turned out to have a sufficient quality for cDNA synthesis.

• Transactions of the Korean hydrogen and new energy society
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• v.7 no.1
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• pp.71-79
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• 1996

Yttrium thin film, 580nm thick, was prepared by electron beam evaporation. Film was hydrogenated room temperature upto 40 bar hydrogen pressure, without any activation process. Hydrogen concentration was determined by a quartz-crystal microbalance(QCM) method. YH2.9 sample was made without any pulverization. Electrical resistance was measured by four-point DC method in the temperature range between room temperature and 30K for various hydrogen concentration, x=0 to 2.9 of YHx sample. Temperature dependent resistance of YH2.9 shows low temperature minimum at 105K, the metal-semiconductor transition at 260K, and a hystersis above 210K.

• ALGAE
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• v.22 no.2
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• pp.125-129
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• 2007

Conventional methods for the isolation and purification of mRNA from Zygnema were unsuccessful because of its high amount of pigments and RNA interactive molecules. In particular, pigments were difficult to remove using conventional protocols because they interacted with RNA during pulverization of the materials. This resulted in total degeneration of RNA in two to three hours. To alleviate this problem, we developed an isolation method that utilized DEAE-cellulose resin. The pigments bound to DEAE anion exchange resin and separated from the RNA. Purified total RNA showed an yield of 50 μg per 100 mg of tissue with this method. The amplified 2nd strand cDNA was distributed 300 bp and over.

• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.4
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• pp.313-319
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• 2015

This study relates to an investigation into semi-dry manufacturing process of BP sludge based on non-heating production method. In this study, we conducted a research into reduction of water content ratio which arose from mixture of BP by-products of high water content ratio(50% or higher) with industrial by-products to use such BP by-products as construction materials in large quantity. We measured the reduction rate of water content ratio at the feeding ratio of water content reduction agent(1:0.5) in BP by-products. The results showed that water content ratio was the lowest with 18.5% in the mixture of PA+CFA(1:0.5). Moreover, water content ratio ranged between approximately 9.2% and 11.4% at the age of 1 day to 2 days at the aging temperature of $20-30^{\circ}C$, suggesting that the water content ratio was in the range within 10% which was a level suitable for use as construction material in this study. Meanwhile, we compared and evaluated the physical properties of non-heated BP by-products based on post-aging pulverization method. The results showed that there was no significant difference, depending on pulverization method. When production efficiency and economic feasibility were taken into consideration, it was found desirable to use fine particle pulverizer or pin mill enabling continuous production.

• 보존과학연구
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• s.29
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• pp.199-220
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• 2008

Hobun(Oyster shell White) is a traditional material used as extender and white pigment from ancient times. The production method of it, however, has been discontinued. We have studied the traditional production method of Hobun by weathering oyster shell, which is one of the traditional ways for preparing Hobun. Reproduction study of manufacturing method of the discontinued traditional material is an important accomplishment of our research. Also this study provides solid background knowledge to stabilize the production and supply of Hobun for the cultural asset repairing materials. The result can be summarized as follows: The production process of Hobun by weathering method takes 5 steps - (1) weathering shells ${\rightarrow}$ (2) washing ${\rightarrow}$ (3) pulverization ${\rightarrow}$ (4) separating fine powder by submerging in water ${\rightarrow}$ (5) drying. The major aim in step (1) is to eliminate organic impurities. In the step (4), the fine particles smaller than $25{\mu}m$ are separated by extracting the supernatant from stirred suspension after heavy particles are submerged. Also, the soluble inorganic impurities can be eliminated through the powder submerge in 15 times water and stirring the suspension 6 hours and changing the water 3~4 times. The final products have high quality with 94.03, 0.52, 2.05 for L, a, b, less than $25{\mu}m$ particle size, fine resistance for discoloration by light and environmental pollution and good workability.