• 원예과학기술지
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• 제30권3호
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• pp.250-255
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• 2012

본 연구는 저면관수와 엽면살포의 두 가지 관수방법에서 세 가지 규산염($CaSiO_3$, $K_2SiO_3$, $Na_2SiO_3$)의 처리가 칼랑코에의 생육에 미치는 영향을 알아보고자 수행하였다. 칼랑코에 'Peperu'를 2010년 7월 17일 삽목하고, 2010년 8월 3일에 삽목묘 중 균일한 개체를 선발하여 상토(토실이상토, 신안그로)가 담긴 10.5cm 포트에 정식하였다. 정식 후 세 가지 규산염($CaSiO_3$, $Na_2SiO_3$, $K_2SiO_3$)을 $50mg{\cdot}L^{-1}$ Si의 농도로 엽면살포 또는 저면관수로 처리하였다. 재배 중의 EC는 1.4-$1.6mS{\cdot}cm^{-1}$로, pH는 6.0의 범위를 유지하도록 공급양액과 공급량을 조절하였다. 규산염 처리 12주째에 수확하여 초장, 경경, 엽록소 함량, 꽃대 수, 꽃대 길이, 생체중과 건물 중, 그리고 식물체 내 축적된 규소함량을 측정하였다. 그 결과 저면관수와 엽면살포 처리 시 초장과 꽃대길이가 줄어들었지만, 엽면살포 처리 시 잎이 썩거나 물러지는 현상이 발견되었다. 세 가지 다른 규산염 종류 사이에서는 저면관수를 통해 공급한 $CaSiO_3$ 처리에서 규소가 칼랑코에 잎에 가장 많이 흡수되었고, 그 영향으로 엽록소 함량이 증가하였다. 신초 조직의 원소 함량은 $CaSiO_3$, $K_2SiO_3$, 그리고 $NaSiO_3$ 처리에 따라 $Ca^+$, $K^+$, 그리고 $Na^+$가 각각 높았고, 저면관수한 $K_2SiO_3$와 $NaSiO_3$ 처리에서는 $Ca^+$와 $Mg^+$, 그리고 $K^+$와 $Ca^+$가 각각 낮았다. 최종적으로 저면관수 $CaSiO_3$ $50mg{\cdot}L^{-1}$ 처리한 칼랑코에의 잎에 Si가 가장 많이 축적되었고, 축적된 Si 함량의 영향으로 엽록소 함량이 증가되었다. 또한 대조구에 비해 규산염처리에서 초장과 같은 생장량이 감소되어 칼랑코에와 같은 소형 분화류의 품질을 향상시켰으나 각 규산염 처리구 사이에서의 생육에는 유의적인 차이가 없었다.

• 마이크로전자및패키징학회지
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• 제6권4호
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• pp.35-39
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• 1999

The $Li_2O-MgO-MgF_2-SiO_2$glasses with addition of $B_2O_3$ were investigated in order to make glass-ceramics for low temperature firing substrate. Glasses were made by melting at $1450^{\circ}C$ in the electronic furnace and crystallized at $750^{\circ}C$. The crystal phases were polycrystalline of lithium boron fluorphlogopite and lithium fluorhectorite. The crystal shape was chanced to granule type from needle type with increasing $B_2O_3$ content. Average particle size of the glass-ceramics after water swelling was 3.77$\mu\textrm{m}$. The optimum sintering temperature and sintering shrinkage of the substrate were $900^{\circ}C$ and 13.4%, respectively.

• 청정기술
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• 제23권1호
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• pp.104-112
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• 2017

해조류로부터 수열 액화 반응을 통해 생성된 원료를 이용하여 수소가스를 생산하기 위해 개질 반응용 상용화 촉매와 $K_2Ti_xO_y$가 첨가된 니켈(Ni) 제조 촉매를 사용하여 반응온도에 따른 수증기 개질 반응을 수행하였다. 반응원료는 해조류 바이오매스를 503 K의 반응온도에서 2시간 동안 수열 액화를 통해 생성된 액화 원료를 사용하였으며, 상용화 촉매(FCR-4-02)와 제조 촉매($Ni/K_2Ti_xO_y-Al_2O_3$, $Ni/K_2Ti_xO_y-SiO_2$, $Ni/K_2Ti_xO_y-ZrO_2/CeO_2$, Ni/$K_2Ti_xO_y$-MgO) 및 반응온도에 따른 수증기 개질 반응의 활성을 비교 연구하였다. 실험결과 제조 촉매 4종 모두 상용화 촉매와 비교하여 반응활성이 높게 나타나는 것이 확인되었으며, 제조 촉매의 지지체에 따라 생성되는 가스의 조성이 달라지는 것이 확인되었다. 특히, 산성이나 염기성을 띄는 $Al_2O_3$와 MgO의 지지체와 중성을 띄는 $SiO_2$의 지지체에서는 CO가 선택적으로 높게 생성이 되었으며 환원성을 띄는 $CeO_2$를 포함하는 지지체에서는 수성가스 전환 반응이 일어나 $CO_2$가 높게 생성됨을 보였다.

• 한국세라믹학회지
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• 제35권10호
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• pp.1101-1106
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• 1998

Various $Zn_{2-x}SiO_4$:xMn based green phosphors were investigated in association with a co-dopant. The co-dopant incorporated into the phosphors are believed to alter the internal energy state of $Zn_{2-x}SiO_4$ : xMn So that the improvement in their intensity could be expected. Phosphor samples were prepared using the solid state reaction therein raw powders are mixed in the acetone and successively fired at $1300^{\circ}C$ for 4 hour. The fired powders are also heated up to $900^{\circ}C$ for 2 hour in the reduced atmoshpere and thereby giving The fired powders are also heated up to $900^{\circ}C$ for 2 hour in the reduced atmosphere and thereby giving rise to conspicuous enhancement of radiative efficiency. Basically the 0.08 mole ratio of the Mn con-centrations has the maximum value of the intensity so that a co-dopant are added to this Mn con-centration. When the Mg is co-doped with Mn luminescent intensity is proven to be promoted significantly.

• 한국세라믹학회지
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• 제22권5호
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• pp.71-75
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• 1985

This study deals with sintering and corrosive behavior of sintered zircons mixed with 5wt% of clay $Cr_2O_3$ $CrO_3-MgO$ aqueous solution and $CrO_3-Mg(OH)_2$ aqueous solution. Measurements were conducted by firing specimens at 135$0^{\circ}C$ 145$0^{\circ}C$ and 155$0^{\circ}C$ 1$650^{\circ}C$ for 3hrs in oxidized and reduced atmospheric conditions. Following results were obtained. 1. Sintered zircon with 5 wt% clay showed that highest compressive strength and the lowest apparent porosity and the other showed less positive result than above specimen in order of zircon with $CrO_3-MgO$ aqueous solution $CrO_3-Mg(OH)_2$ aqueous solution and $Cr_2O_3$. 2. The more firing temperature increased the more its strength improved and porosity decreased and specimen which was fired over 155$0^{\circ}C$ and in reduced atmospheric condition showed better results. 3. Zircon with additives which was fired over 155$0^{\circ}C$ showed the evidence of thermal dissociation but it was not rebonded completely during cooling. 4. Zircon with $CrO_3-MgO$ aqueous solution and $CrO_3-Mg(OH)_2$ aqueous solutiion showed more corrosive resistance than zircon itself and zircon-clay system.

• 한국세라믹학회지
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• 제47권6호
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• pp.613-617
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• 2010

Ferro-Nickel slag is one of the by-products in Ferro-Nickel manufacturing process. The slag is composed of $SiO_2$, MgO, $Fe_2O_3$ and others. But the slag has been buried at landfill despite having valuable elements. This study tried to extract Mg ion and fabricate Mg compound from ferro-nickel slag using hydrochloric acid solution. Mg ion was extracted with Si, Fe and other ions in HCl solution. So reprocess was needed for gaining high purity Mg ion. It was thought that Si ion or $SiO_2$ precipitated in HCl solution and removed from solution in filtering process. Fe ion converted into $Fe(OH)_3$ after reacted with $NH_4OH$ and precipitated in HCl solution. After these process, the filtrate was composed of high purity Mg ion. $MgCl_2{\cdot}NH_4Cl{\cdot}6H_2O$ was obtained through drying of filtrate and this product was changed into MgO by burning process ($600^{\circ}C$-30 min). That is, 1st material or solution for manufacturing 2nd product was fabricated using acid dissolution method and other treatments.

• 암석학회지
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• 제6권2호
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• pp.123-132
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• 1997

활석[$Mg_3Si_4O_{10}(OH)_2$]은 그 성분의 산화물을 200 MPa, $600^{\circ}C$에서 열수 반응시켜 쉽게 합성할 수 있다. 엔소필라이트[$Mg_3Si_4O_{10}(OH)_2$]는 그 성분 산화물을 200 MPa, $750^{\circ}C$에서 반응시키면 활석, 엔스타타이트($MgSiO_3$), 석영이 생성된다. 저압 내지 중압의 변성작용에서 엔스타타이트와 활석의 공새은 활석 + 4 엔스타타이트=엔소필라이트의 반응(Greenwood, 1963)에 의해 준 안정한 광물조합이며 엔소필라이트가 안정하다. 그러므로 저압 내기 중압 환경에서 활석의 고온한계는 엔스타타이트와 석영이 형성되는 반응보다 엔소필라이트 석영이 형성되는 반응으로 한정된다(Greenwood, 1963; Chernosky et al., 1985). 그러나 위의 200 MPa, $750^{\circ}C$ 열수반응에서 활석과 엔스타타이트와 석영의 공생은 엔소필라이트의 형성과 안정성에 대하여 의문을 제기하게 한다. 본 연구는 열역학적으로 계산되어 얻어진 7 활석=3 엔소필라이트 + 4 석영 + 4 $H_2O$ 반응 온도 보다 고온에서 활석의 안정성에 대하여 실험하였다. 열수 반응은 41-243 MPa 680-$760^{\circ}C$에서 실시하였다. 화학반응 활석=3 엔스타타이트 + 석영 + $H_2O$는 100MPa 699$^{\circ}C$]<710에서 평형을 이루고, 200 MPa, $740^{\circ}C$에서는 활석이 안정하고, 40 MPa, $680^{\circ}C$와 250 MPa, $760^{\circ}C$에서는 엔스타타이트가 안정하다.

• 한국세라믹학회지
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• 제37권6호
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• pp.604-611
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• 2000

Glass-ceramics containing a cordierite (2MgO-2Al2O3-5SiO2) as a main crystal phase was prepared from MgO-Al2O3-SiO2 system glass through a controlled 2-step heat treatment for the application to magnetic memory disk substrate for higher storage capacity. Parent glasses prepared with addition of CeO2 as a fulx and TiO2 as a nucleating agent were crystallized by a 2-step heat treatment i.e. nucleation and crystal grwoth. Then the maximum nucleation and crystal growth rates were investigated and several properties such as bending strength, surface hardness and surface roughness were also studied for heat treated glass. As a result, only a $\alpha$-cordierite was precipitated as a main crystal phase for all heat treatment conditions and the maximum nucleation and crystal growth rates were 2.4$\times$109/㎣.hr at 80$0^{\circ}C$ and 0.3${\mu}{\textrm}{m}$/hr at 915$^{\circ}C$ respectively. After being nucleated at 80$0^{\circ}C$ for 5 hours and then crystallized at 915$^{\circ}C$ for 1 hour, the heat treated glass had a crystal volume fraction of 17.6% and crystal size fo 0.3${\mu}{\textrm}{m}$, and showed the optimum properties for the application to magnetic memory disk substrates as follows. ; Bending strength of 192 MPa, Vidkers hardness of 642.1kgf/$\textrm{mm}^2$, and surface roughness of 27$\AA$.

• 한국세라믹학회지
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• 제20권1호
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• pp.25-30
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• 1983

This experiment was studied in the system of (1-x) CaO MgO $2SiO-Al_2O_3$ to investigate forming of solid solution. The technique empolyed was the well known water-quenching method. Differential thermal analysis of the each glass water quenched indicated that under 30 mole% $Al_2O_3$ was lowered with increasing of the amount of $Al_2O_3$ It was supposed by X-ray diffraction patterns of each specimen sintered at various temperature that only solid solution was formed under the 30mole % $Al_2O_3$ compositions solid solution and anorthite were formed at the 20mole% $Al_2O_3$ composition anorthite solid solution and spinel$(MgAl_2O_4)$ were formed over the 40mole% $Al_2O_3$ compositions. The maximum density and thermal expanison coefficient was 2.89g/cm 7.74x106./C$^{\circ}$ respectively in the composi-tion of 10 mole% $Al_2O_3$ . All the specimens showed linear thermal expansion behavior. Microhardness was as high as 850kg/nm2 in the composition of 5, 10, 20 mole % $Al_2O_3$ and dielectric constant was 7.3-6.9.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.593-596
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• 1999

This paper presents a process optimization of antireflectiun (AR) coating on crystalline Si solar cells. Theoretical and experimental investigations were performed on a doble-layer AR(DLAR) coating of MgF$_2$/CeO$_2$, We investigated CeO$_2$ films as an All layer because they hale a proper refractive index of 2.46 and demonstrate the same lattice constant as Si substrate. RF sputter grown CeO$_2$ film showed strong dependence on a deposition temperature. The CeO$_2$ film deposited at 400 $^{\circ}C$ exhibited a strong (111) preferred orientation and the lowest surface roughness of 6.87 $\AA$. Refractive index of MgF$_2$ film was measured as 1.386 for the most of growth temperature. An optimized DLAR coating showed a reflectance as low as 2.04 % in the wavelengths ranged from 0.4 7m to 1.1 7m. We achieved the efficiencies of solar cells greater than 15% with 3.12 % improvement with DLAR coatings . Further details on MgF$_2$, CeO$_2$ films, and cell fabrication Parameters are presented in this paper.