• 한국토양비료학회지
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• 제7권3호
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• pp.155-161
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• 1974

약제(藥劑) 무방제상태(無防除狀態)에서 벼에 대한 규산질비료(珪酸質肥料)의 분시효과를 검토(檢討)한 결과(結果) 규회석(珪灰石)이나 합성고농도규산용융물(合成高濃度珪酸熔融物) 공(共)히 전량기비구(全量基肥區)의 규산흡수량(珪酸吸收量)이 전생육기간(全生育期間) 가장 높았으며 생육(生育)이 진행(進行)됨에 따라 분시구(分施區)의 짚중규산함량(中珪酸含量)과의 차이(差異)는 좁혀지고 수확기(收穫期)에는 거의 차이(差異)가 없었다. 비종간(肥種間)에 있어서는 역용성(易溶性) 규산용융물(珪酸熔融物)의 비효가 규회석(珪灰石)보다 높았으며 추비효과도 현저(顯著)하였다. 분시(分施)에 의(依)하여 무방서(無防徐)에 의한 50%의 엽도열병(葉稻熱病) 이병률(罹病率)을 규회석(珪灰石)은 20~40%로 감소(減少)시켰고 합성고농도규산용융물(合成高濃度珪酸熔融物)은 5~15%로 감소(減少)시켰다. 또한 수수도열병(穗首稻熱病)도 무방제구(無防除區)의 50% 이병율(罹病率)을 각각(各各) 20%로, 10%로 감소(減少)시겼다. 즉 규산질비료(珪酸質肥料)의 시비시기(施肥時期)는 전량기비(全量期肥)가 가장 우수(優秀)하나 추비(追肥)로써도 사용(使用)될 수 있으며 최고분벽기(最高分蘗期) 이전(以前)에 시용(施用)되어야 하고 추비용(追肥用) 규산질비료(珪酸質肥料)는 난용성물질(難溶性物質)보다 유효규산함량이 높고 역용성(易溶性) 규산용융물(珪酸熔融物)을 사용(使用)하는 것이 추비효과를 높일 수 있으나 미세분말(微細粉末)의 풍산(風散)과 엽부착등(葉附着等)을 고려(考慮)한 시비방법(施肥方法)이 모색(摸索)되어야겠다.

• 한국작물학회지
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• 제14권
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• pp.71-77
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• 1973

저위생산지인 누수성 사질토에 대한 종합 개량자재로서의 용성인비에 대한 시용효과시험을 실시한 결과 다음과 같은 결론을 얻었다. 1. 수도 수량은 용린 시용량 증가와 더불어 33-93kg 정도의 수량증가로 지수 10-27%까지 증수성을 나타내고 있으며 이는 수량구성요소중 수수, 및 등숙비율이 증가하였고 도열병 병반률이 적은데 있으며 시용적량은 200-250kg/10a 정도이다. 2. 시험후 토양중의 각 요소별 함량변화에 있어 시용량이 증가함에 따라 pH치, 유효인산, 가용성규산, 치환성석회 치환성고토 및 염기치환용량 등이 증가되었으며 치환성 가리는 변화가 없었다. 3. 토양중 각 요소별 수량 및 수량구성요소간의 상관을 보면 인산 및 규산은 현미수량, 등숙비율 및 수수(규산에 한함)에 있어서 통계적 유의한 정의 상관이 있었으며 그 밖에는 유의적상관관계를 인정할 수 없었다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.705-710
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• 2001

So for the quartz-glassy crucible wastes which was used for pulling up silicon-single-crystal ingot have simply reused for refractory raw-materials, or exhausted. This study is concerned on the advanced recycling-technology that is obtained by the proper micro-particle preparation process in order to fabricate fine amorphous silica filler for EMC (Epoxy Molding Compound). Therefore, this paper will deal with the physical, chemical and thermal pre-treatment process for efficient impurity removal and with the proper micro-particle process for producing the amorphous silicafiller. In view of the results, if the chemical, physical and thermal pre-treatment process for efficient elimination of impurity was passed, the purity of wasted fused glassy crucible is almost equal to the its of first anhydrous quartz glass. Thus, it was understood that this wasted fused glassy crucible was sufficient value of recycling, though it was damaged. When the ingot was fabricated, Phase transformation of crystallization by heat treatment (heat hysteresis phenomenon) was not changed. So, it was understood that as fused silica in the amorphous state, as It is, recycling possibility was very high

• Bulletin of the Korean Chemical Society
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• 제27권9호
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• pp.1429-1432
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• 2006

Polyaromatic hydrocarbons were separated by a capillary supercritical fluid chromatographic (SFC) column and detected by a UV detector at the wavelength of 280 $\mu$m. The temperature-controlled restrictor was designed for UV detection. The temperature-controlled restrictor is a 20 cm length of deactivated fused silica of 7 mm i.d. which is held right after UV detector of the capillary SFC. The temperature of the restrictor will control the flow rate of the supercritical carbon dioxide mobile phase through the capillary column in SFC. Thus as the pressure in the column is increased from 1500 psi to 4000 psi during a pressure program, the temperature of 7 $\mu$m fused-silica tube can be varied from 100 to 350 ${^{\circ}C}$ to maintain a constant flow rate.

• BMB Reports
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• 제31권4호
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• pp.384-390
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• 1998

DNA fragments (51-587 bp) were separated by capillary electrophoresis using entangled polymer, hydroxyethylcellulose, in uncoated fused silica capillary columns. The factors affecting the separation of DNA fragments with hydroxyethylcellulose media were evaluated, i.e., the concentration of buffer and entangled polymer, effects of additives (methanol, ethidium bromide, EDTA), temperature, and injection methods. Maximum performance was obtained by adding 5% methanol in 0.5% hydroxyethylcellulose solution at $30^{\circ}C$. Addition of methanol in polymer media increased the resolution of small size DNA fragments (< 100 bp). On the other hand, addition of ethidium bromide and EDTA, which are commonly used in conventional DNA separation, reduced the resolution of DNA fragments in the polymer solution. It turns out that the separation behavior of DNA in entangled polymer is more sensitive to the running condition compared to that in polyacrylamide gel-filled capillary, but the reproducibility of DNA separation in entangled polymer is reliable.

• 소성∙가공
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• 제21권2호
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• pp.138-143
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• 2012

A polishing method using magnetorheological (MR) fluid has been developed as a new precision technique to obtain a fine surface. The process uses a MR fluid that consists of magnetic carbonyl iron (CI) particles, nonmagnetic polishing abrasives, water and stabilizers. But the CI particles in MR fluids cause a severe corrosion problem. When coated with Xanthan gum, the CI particles showed long-term stability in corrosive aqueous environment. The surface roughness obtained from the MR polishing process was evaluated. A series of experiments were performed on fused silica glass using prepared slurries and various process conditions, including different polishing times. Outstanding surface roughness of Ra=2.27nm was obtained on the fused silica glass. The present polishing method could be used to produce ultra-precision micro parts.

• 대한화학회지
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• 제45권2호
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• pp.143-148
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• 2001

본 연구에서는 작은 양의 시료를 분석할 수 있는 이온 크로마토그래피용 open tubular capillary 컬럼을 개발하였다. 내경이 작은 모세관 컬럼을 사용하는 경우 이동상의 유속은 보통 1~10㎕/min 정도 되고 컬럽의 길이는 1.0~5.0m 정도이다. 컬럼은 fused silica 모세관(내경 : 50㎛)과 DMEOHA latex particles를 이용하여 만들었다. 또한 이런 모세관 컬럼에 맞는 새로운 전도도 셀과 억압장치도 함께 개발하여 사용하였다. 이 모세관 컬럼을 이용하여 실제 음이온들(fluoride, nitrite, chlorate, phosphate, sulfate)을 분석한 결과재현성 있고 좋은 크로마토그램을 얻었다.

• 한국주조공학회지
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• 제31권5호
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• pp.267-273
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• 2011

Erosion and thermal shock resistance of several refractory materials have been investigated, which are expected to be used as nozzles in a planar flow casting equipment for amorphous alloys. The test was conducted on five materials; graphite, boron nitride, fused silica, alumina and zirconia. Test specimens were preheated and dipped into the melt of carbon steel and amorphous alloys. Some test specimens were rotated to develop high erosion and to shorten the test periods. Fused silica and boron nitride specimens showed the excellent erosion and thermal shock resistance irrespective of the kind of melt and melting atmosphere.

• 한국세라믹학회지
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• 제35권9호
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• pp.923-932
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• 1998

Al2O3/Al composites were produced by displacement reaction method which was carried out by imm-ersing the sintered silica preform which was prepared form fused silica powder in molten aluminu. an ac-tivation energy of 94kJ/mole was calculated from Al-SiO2 reaction data in 1000-130$0^{\circ}C$ temperature range With increase of reaction temperature the alumina particle in the Al2O3/Al composites produced with pur metal Al showed grain growth and the growth of alumina particle in Al2O3/Al composite produced by using of Mg contained Al alloy was inhibited. The flexural strength of Al2O3/Al composites produced at 100$0^{\circ}C$ showed the highest value as 393 MPa. Flexural strength of the composite fabricated at 85$0^{\circ}C$ showed higher deviation than that of the composite produced at above 100$0^{\circ}C$ Low flexural strength of the composite fa-bricated at 120$0^{\circ}C$ due to the growth of pore and alumina particle size. The hardness of composites de-pended on alumina content in Al2O3/Al composite decreased with increasing of aluminium content in case the same alumina content and increased with increasing of silicon content in composite.

• 한국세라믹학회지
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• 제53권2호
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• pp.246-252
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• 2016

Complex designed silica-based ceramic cores were fabricated by ceramic injection molding. Slow heating rate (0.2K/min) for debinding restrained bloating on the surface of ceramic cores. To investigate effect of sintering conditions on mechanical properties of ceramic cores, green bodies were sintered at temperatures in a range from $1150^{\circ}C$ to $1400^{\circ}C$ for various dwelling times (6 h to 48 h). Sintering above $1300^{\circ}C$ for 12 h and dwelling time over 24 h at $1200^{\circ}C$ reduce the flexural strength and increase the linear shrinkage of ceramic cores. Cristobalite, formed by high sintering temperature or long dwelling time, induces reduction of mechanical properties due to its phase transformation, which is accompanied by volume contraction and microcracking. Ceramic core sintered at $1200^{\circ}C$ for 12 h endured wax patterning and shell molding, and was manufactured successfully.