• Korean Journal of Soil Science and Fertilizer
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• v.19 no.4
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• pp.321-325
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• 1986

A laboratory experiment was conducted to investigate silica solubility in soil with specific reference to the characteristics of iron refinery slag and wollastonite. The results are as follows; 1. The slilia concentrations successively extracted by distilled water and N-NaOAc (pH 4.0) in soil treated with the two silicate fertilizers, is higher in iron refinery slag than in wollastonite, while the pH values of soil-fertilizer suspensions successively extracted by distilled water were the opposite. 2. Silica concentrations due to increasing of fertilizer application were decreased in iron refinery slag-soil suspensions but the concentrations were increased in wollastonite-soil suspensions. 3. The amounts of silica adsorbed in different pH of soil suspension were maximized under the condition maintained pH of near to 9.4.

• Tuberculosis and Respiratory Diseases
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• v.48 no.4
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• pp.500-512
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• 2000

Background : To evaluate the efficacy of two methods of obtaining lung recruitment to reduce ventilator-induced lung injury(VILI). Methods : Fifteen New-Zealand white rabbits were ventilated in the pressure-controlled mode while maintaining constant tidal volume(10 ml/kg) and fixed respiration rate. Lung injury was induced by repeated saline lavage (PaO2<100 mmHg), and the pressure-volume curve was drawn to obtain Pflex. The animals were then randomly assigned to three groups and ventilated for 4 hours. In the control group(n=5), positive end-expiratory pressure(PEEP) less than that of Pflex by 3 mmHg was applied throughout the study. In the recruitment maneuver(RM) group(n=5), RM(CPAP of 22.5 mmHg, for 45 seconds) was performed every 15 minutes in addition to PEEP level less than Pflex by 3 mmHg This phrase is unclear. In the Pflex group, PEEP of Pflex was given without RM. Gas exchange, lung mechanics, and hemodynamics parameters as well as pathology were examined. Results : 1) Both the control and RM groups showed decreasing tendency in PaO2 with time. There was significantly decreased PaO2 at 4 hr compared to Ihr(p<0.05). But in the Pflex group, PaO2 did not decrease with time(p<0.05 vs other groups at 3, 4 hr). PaCO2 did not show significant difference among the three groups. 2) There was no significant difference in static compliance and plateau pressure. Mean blood pressure and heart rate also did not show any significant difference among the three groups. 3) The pathologic exam showed significantly less neutrophil infiltration in the Pflex group than in the control group(p<0.05). There was borderline significant difference in hyaline membrane score among the groups (p= 0.0532). Conclusion : Although recruitment maneuver of the injured lung may be important in decreasing VILI, it alone may not be sufficient to minimize VILI.

• Journal of Korea Foundry Society
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• v.2 no.3
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• pp.2-15
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• 1982

In this study, the influenced of graphite shape on the boriding of cast iron and boride structure was investigated. Gray cast iron, ferritic and pearlitic ductile cast iron were borided at 750,850,900 and $950^{\circ}C$ for 1,3 and 5 hours by powder pack method with the mixture of $B_4C_9\;Na_2B_4O_7$, $KBF_4$ and Shc. The boride layer was consisted of FeB(little), $Fe_2B$ (main) and graphite. Some possibility of the existence of unknown Fe-B-C compound in the boride layer was suggested. And precipitates in the diffusion zone was $Fe_3(B,C)$. The concentration of Si and precipitation of $Fe_3(B,C)$ in the ${\alpha}$ layer raised the hardness of this Zone. The depth and hardness of boride layer increased with the increase of treating temperature and tim. But high temperature (over $950^{\circ}C)$ caused pore at graphite position and long treating time (5hrs) sometimes caused formation of graphite layer beneath the boride layer. So, for the practical application of borided cast iron, treating in short time and at low temperature was recommended. And for ductile cast iron, ferritizing or pearlitizing heat treatment was seemmed to be possible at the same time with boriding. The graphite in the boride layer was deeply concerned with the qualitx and characteristics of the boride layer. And it greatly influenced on the shape of the boride phase, structure of the boride layer. Generally speaking, the existance of graphite restrained the growth of the boride phase. But the boundary between the gsaphite and the matrix acted as the shortcut of boron diffusion. So, for gray cast iron, the graphite layed length-wise led the formation of boride layer.

• Advances in concrete construction
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• v.5 no.4
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• pp.313-330
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• 2017

Geopolymer is a sustainable concrete, replaces traditional cement concrete using alternative sustainable construction materials as binders and alkaline solution as alkaline activator. This paper presents the strength characteristics of geopolymer concrete (GPC) developed with fly ash and GGBS as binders, combined Sodium silicate ($Na_2SiO_3$) and Sodium Hydroxide (NaOH) solution as alkaline activators. The parameters considered in this research work are proportions of fly ash and GGBS (70-30 and 50-50), curing conditions (Outdoor curing and oven curing at $600^{\circ}C$ for 24 hours), two grades of concrete (GPC20 and GPC50). The mechanical properties such as compressive strength, split tensile strength and flexural strength along with durability characteristics were determined. For studying the durability characteristics of geopolymer concrete 5% $H_2SO_4$ solutions was used and the specimens were immersed up to an exposure period of 56 days. The main parameters considered in this study were Acid Mass Loss Factor (AMLF), Acid Strength Loss Factor (ASLF) and products of degradation. The results conclude that GPC with sufficient strength can be developed even under Outdoor curing using fly ash and GGBS combination i.e., without the need for any heat curing.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.3
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• pp.151-156
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• 2006

This study was conducted to investigate effects of granular silicate fertilizer(GSF) on growth, nutrient uptake and quality rice during cultivation. Then the chemical properties of paddy soil used for the cultivation test were pH 5.9, O.M. $13.7g\;kg^{-1}$, avail. $P_2O_5$ $48.9mg\;kg^{-1}$, and avail. $SiO_2$ $79.8mg\;kg^{-1}$. The amounts of GSF treated in the paddy soil were 0, 76, 185, 229, 413 and $489kg\;10a^{-1}$ for control, S-100(control amounts of soil available $SiO_2$), S-130, S-160, S-190 and for S-210 treatments, respectively. At results of rice growth leaf length and tiller number were more remarkable results at treatments of GSF than control. The leaf length of rice at S-100 treatment was the highest as 99.4 cm and the tiller number was the highest as 18.9 ear number at S-130 treatment. At the results of rice yield parameters, the grain and straw yield of rice were showed that all of the GSF applicated treatments were more predominant level than at the control, especially their levels were the highest values as 841.5 and $815.2kg\;10a^{-1}$ at the S-160 treatment, respectively. Also at the results of quality parameters on rice grain, a perfect kernel in the GSF applicated treatments was more increased than at control, but a broken kernel rate was inversely decreased. In results of these aspects, the chemical properties of white rice and the taste of rice by the Toyo MA-90A(Toyo rice quality taster) instrument, amylose content was the lowest value as 18.7%(generally about 20%) at S-160 treatment. Also, Mg/K ratio and rice taste value were the highest level as 0.58 and 69.1 at the S-190 and S-160 treatments respectively. The harvest yields of rice at S-160 and S-190 treatments from these growth factors were more produced about 8-13% than control. Therefore, the GSF application for rice cultivation from these results should be expected to obtain the positive effects as enhancement of rice harvest yield and improvement of quality on the cooked rice taste. Amount of GSF application could be recommended as around $200mg\;kg^{-1}$ for optimal and economical rice cultivation.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.4
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• pp.373-379
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• 1998

Fly ash application with a rate 0, 50, 100, $150Mg\;ha^{-1}$ in clay loam paddy, which had properties of pH 5.3 and low contents of silicate, gave a positively residual effects on the growth of rice crop subsequent to malting barley. The responses of rice yields to fly ash application were in the order of bituminous coal fly ash(BCFA) 100 > 150 > 50 > anthracite fly ash(AFA) 50 > 100 > none > AFA $150Mg\;ha^{-1}$. As a result, yields responses of milled rice were ranged from $6.2(50Mg\;ha^{-1}){\sim}14.4%(100Mg\;ha^{-1})$ by BCFA and from $-0.6(150Mg\;ha^{-1}){\sim}6.6%(50Mg\;ha^{-1})$ by AFA showing maximum yields of 5.084 and $4.738Mg\;ha^{-1}$ by the former and the latter, respectively. Rice plant showed lodging indices ranging from $20(50Mg\;ha^{-1}){\sim}40%(150Mg\;ha^{-1})$ by BCFA and from $1.3(150Mg\;ha^{-1}){\sim}15%(50Mg\;ha^{-1})$ by AFA at harvesting stage. In especial, soils applicated with BCFA contained a good fertility in terms of pH, available $P_2O_5$ and $SiO_2$, and exchangeable Ca and Mg etc. so that possibly harbored 3yr-residual effects of the fly ash on crop subsequent to this rice.

• Proceedings of the Korean Vacuum Society Conference
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• 1998.02a
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• pp.24-24
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• 1998

반도체장비를 포함하는 초고진공장비의 園훌化가 급속히 그리고 절실히 요구되고 있는 것이 현실정이다. 當面해서 실현할 국산진공장비의 대상은 廣範圍하다. 즉, 각종 진공 pump ( (rotary, dry, diffusion, cryo, ion, turbo melecular pump), 진공 chamber, 진공 line, gate valve 를 위 시 한 진공 V머ve, flange, gasket, fl않d야lU, mainpulater 퉁 진공 部品이 다. 진공계 의 핵심 은 適切하고 優良한 진공재료의 선태파 사용이다. 진공장비는 사용자가 원하는 진공도를 원하 는 시간 동안 륨空度를 유지해 주어야 한다. 진공재료 선태의 기준사항은:(1) 기체의 透過성 (2) 薰했훌 (3) 혔體放出특성 - -outgassing과 degassing- (4) 機械的 량훌度 (5) 온도 의존성 (6) 化學톡성 (7) 加I성 및 鎔接 성 (8) 課電특성 (9) 磁氣특성 (10) 高速함子 및 放射線 특성 (11) 經濟성 및 調達생 둥이 다. 우량한 초고진공계재료는 풍부하게 개발되어 왔고, 또 新材料들이 개발되고 있다. 여기에서는 주로 초고진공 내지는 극고진공계의 構造材料, 機能材料, 部品材料 일반파 몇가지 신재료의 특 성에 관해서 記述한다. M Mild SteeHSAE, 1112, 1010, 1020, 1022, etc)., S Stainless SteeHAlSI, 304, 304L, 310, 316, 321, 347): 구조재료, chamber, fl하1ges A Aluminum과 Alloys (1060, 1100, 2014, 4032, 6(뻐1): 구조재료, chamber, flanges, gaskets A AI, Al 떠loy는 SS에 代替하는 역 할올 시 작하고 있다. C Copper, Copper Alloys(C11$\alpha$)0, C26800, C61400, Cl7200): 내장인자, gasket, cryopanel, tubing T Titanium, Ziriconium, Haf띠um 및 Alloys: 특히 Ti은 10n pump 용 getter material 이 외 에 U UHV,XHV용 chamber계로서 관심올 끌고 있다. N Nickel, Nickel Alloys (200, 204, 211, monel, nichrome): 부식 방지 , 전자장치 , 자기 장치 귀 금속(Ag, Au, Pt, Pd, Rh, Ir, Os, Ru): 보조부품, gasket, filament, coating, thermocouple, 접 합부위 T TiC, SiC, zrC, HfC, TaC 둥의 탄화물과, BN, TiN, AlN 동의 질화물, 붕화물이 둥장하고 었 다. 유리: Soda Lime, Borosilicate, Potash Soda Lead: View Port, Chamber envelope C Ceramics: AlZ03, BeO, MgO, zrOz, SiOz, MgOzSiOz, 3Alz032SiOz, Z$textsc{k}$hSiOz S상N4: e electrical, thermal insulators, crucibles, boats, single crystals, sepctr려 windows 저자는 최근 저자들이 발견한 Zr-Ti-Cu-Ni-Be amorphous alloys coated cham뾰r가 radiation p proof로 이용될 수 있는 사실을 점검하고 었다 .. Z.Y. Hua 들은 Cs3Sb를 새로운 photocathode 재료로 보고하고 있다.

• Journal of the Mineralogical Society of Korea
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• v.29 no.2
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• pp.59-71
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• 2016

To investigate the sorption characteristics of Cs, which is one of the major isotopes of nuclear waste, on natural zeolite chabazite, XRD, EPMA, EC, pH, and ICP analysis were performed to obtain the informations on chemical composition, cation exchange capacity, sorption kinetics and isotherm of chabazite as well as competitive adsorption with other cations ($Li^+$, $Na^+$, $K^+$, $Rb^+$, $Sr^{2+}$). The chabazite used in this experiment has chemical composition of $Ca_{1.15}Na_{0.99}K_{1.20}Mg_{0.01}Ba_{0.16}Al_{4.79}Si_{7.21}O_{24}$ and its Si/Al ratio and cation exchange capacity (CEC) were 1.50 and 238.1 meq/100 g, respectively. Using the adsorption data at different times and concentrations, pseudo-second order and Freundlich isotherm equation were the most adequate ones for kinetic and isotherm models, indicating that there are multi sorption layers with more than two layers, and the sorption capacity was estimated by the derived constant from those equations. We also observed that equivalent molar fractions of Cs exchanged in chabazite were different depending on the ionic species from competitive ion exchange experiment. The selectivity sequence of Cs in chabazite with other cations in solution was in the order of $Na^+$, $Li^+$, $Sr^{2+}$, $K^+$ and $Rb^+$ which seems to be related to the hydrated diameters of those caions. When the exchange equilibrium relationship of Cs with other cations were plotted by Kielland plot, $Sr^{2+}$ showed the highest selectivity followed by $Na^+$, $Li^+$, $K^+$, $Rb^+$ and Cs showed positive values with all cations. Equilibrium constants from Kielland plot, which can explain thermodynamics and reaction kinetics for ionic exchange condition, suggest that chabazite has a higher preference for Cs in pores when it exists with $Sr^{2+}$ in solution, which is supposed to be due to the different hydration diameters of cations. Our rsults show that the high selectivity of Cs on chabazite can be used for the selective exchange of Cs in the water contaminated by radioactive nuclei.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.139-139
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• 2016

반도체 다마신배선용 도금용 구리도금첨가제는 대표적으로 accelerator, suppressor 및 leveler 첨가제를 사용하여 다마신 패턴을 채우고 평탄화를 시킬 수 있다. Si 반도체 공정기술에 기반한 정확한 구조분석을 통해 각각의 첨가제의 기능이 비교적 체계적으로 연구되었으며, 최근에는 유속영향을 많이 받는 것으로 알려진 leveler 첨가제에 대한 연구가 활발히 진행되고 있다. 본 연구는 대표적 leveler 첨가제의 하나인 Janus Green B(JGB, $C_{30}H_{31}ClN_6$)를 0 ~ 1 mM을 첨가하여 Si 기판위에 증착된 Cu 씨드층 상의 도금후 표면상태 및 불순물의 농도를 분석하고, 이 박막층들의 결정립 성장 경향성을 electron backscattered diffraction(EBSD) 분석을 통해 진행하였다. C, H, N 등의 불순물이 JGB 농도와 선형적 관계를 가지고 증가하는 것을 알 수 있었으며, S와 O의 불순물도 JGB 농도 증가에 따라 증가하는 것을 알 수 있었다. 또한 0.1 mM 첨가한 경우에 60% 정도 결정립 성장이 진행된 것을 알 수 있었으며, 0.2 mM을 넣은 경우에는 결정립 성장이 일어나지 않은 것을 알 수 있었다. 흥미로운 점은 4 point probe를 통한 면저항 측정을 통해 EBSD를 통한 결정립성장이 관찰되지 않은 0.2 mM JGB를 첨가한 경우에 대해서도 면저항의 감소가 관찰되며, 오히려 JGB 농도가 높을수록 이러한 면저항의 감소가 빠르게 시작되는 것을 관찰할 수 있었다. 이는 JGB 농도 증가에 따라 박막층의 불순물의 농도가 증가하고 막내에 존재하는 불순물의 농도가 증가하면 내부응력장이 커짐으로 인해 더욱 빠른 속도로 불순물의 재배치가 일어난 것으로 보인다. 이러한 불순물이 결정립계면에 편석되는 경우에 pinning을 통해 결정립계면의 이동을 저하시킬 수 있으므로 결정립의 성장 억제가 가능해진 것으로 판단된다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.169-169
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• 2008

To keep pace with scaling trends of CMOS technologies, high-k metal oxides are to be introduced. Due to their high permittivity, high-k materials can achieve the required capacitance with stacks of higher physical thickness to reduce the leakage current through the scaled gate oxide, which make it become much more promising materials to instead of $SiO_2$. As further studying on high-k, an understanding of the relation between the etch characteristics of high-k dielectric materials and plasma properties is required for the low damaged removal process to match standard processing procedure. There are some reports on the dry etching of different high-k materials in ICP and ECR plasma with various plasma parameters, such as different gas combinations ($Cl_2$, $Cl_2/BCl_3$, $Cl_2$/Ar, $SF_6$/Ar, and $CH_4/H_2$/Ar etc). Understanding of the complex behavior of particles at surfaces requires detailed knowledge of both macroscopic and microscopic processes that take place; also certain processes depend critically on temperature and gas pressure. The choice of $BCl_3$ as the chemically active gas results from the fact that it is widely used for the etching o the materials covered by the native oxides due to the effective extraction of oxygen in the form of $BCl_xO_y$ compounds. In this study, the surface reactions and the etch rate of $Al_2O_3$ films in $BCl_3/Cl_2$/Ar plasma were investigated in an inductively coupled plasma(ICP) reactor in terms of the gas mixing ratio, RF power, DC bias and chamber pressure. The variations of relative volume densities for the particles were measured with optical emission spectroscopy (OES). The surface imagination was measured by AFM and SEM. The chemical states of film was investigated using X-ray photoelectron spectroscopy (XPS), which confirmed the existence of nonvolatile etch byproducts.