• 한국세라믹학회지
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• 제43권9호
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• pp.575-581
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• 2006

To precipitate the complex gel of flux and aluminum hydroxides gel, aqueous solution of the mixture of $Na_2CO_3\;and\;Na_2PO_4{\cdot}12H_2O$ was added with stirring in aqueous solution of the mixture of $Al_2(SO_4)_3{\cdot}14{\sim}18H_2O,\;Na_2SO_4$, and then the complex gel was aged in $0{\sim}30h\;at\;90^{\circ}C$. As aging time passed, the aluminum hydroxides was grown into the acicular AlO(OH) gel. Also, aging time had an effect on physical properties of the AlO(OH) gel and on crystal growth of the flaky ${\alpha}-Al_2O_3$ prepared by molten-salt precipitation. In this study, the complex gel was crystallized in temperature range of $400{\sim}1,200^{\circ}C$ after drying at $110^{\circ}C$, and then it was investigated to effect of aging time on precipitation temperature, size, thickness, morphology and particle size distribution of the flaky ${\alpha}-Al_2O_3$ crystal. As aging time passed, the flaky a${\alpha}-Al_2O_3$ crystal showed a tendency toward an increase in size and thickness as result from an increase in BET surface area and pore volume of the acicular AlO(OH) gel.

• 생태와환경
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• 제36권4호통권105호
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• pp.447-454
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• 2003

부영양호의 수질정화를 위하여 알루미늄 응집제를 호수에 첨가하고 조류와 부유물의 침강제거효과, 및 인의 감소효과를 측정하였다. 서울 석촌호와 강원대학교 구내 연못을 대상으로 8회에 걸쳐 첨가량을 달리하여 실시하였다. 7회의 처리에서는 황산알루미늄을 사용하였고 1회는 PAC를 사용하였다. 부유물질의 침강제거효과는 첨가량에 따라 좌우되었다. 10.0 mgAl/l를 첨가한 경우에는 부유물질, 조류, 인 등이 완전히 제거되었으나, 3.3 mgAl/l와 1.8 mgAl/l를 첨가한 경우에는 부분적인제거 효과가 있었다. 그러나 0.45 mgAl/l로 첨가한 경우에는 거의 개선효과가 보이지 않았다. 알루미늄 첨가가 부유물을 침전제거에 효과를 나타내기 위해서는 최소역치 (약 5 mgAl/l) 이상을 투여하여야 하는 것으로 결론지을 수 있다. 효과 지속시간은 외부로부터의 추가부하량 유입에 의해 좌우되는 것으로 보인다. 석촌호에서는 인근 하천수의 펌핑에 의해 곧 다시 혼탁해 졌으며, 구내연못에서는 강우후 주변의 토사가 유입되거나 지하수 펌핑으로 영양염류가 유입되면 곧 다시 조류가 번성하고 혼탁해 졌다. 응집제 투여의 결과로 pH가 지나치게 낮아지는 피해나 어패류에 대한 유해성 징후는 발견되지 않았다. 외부 오염원을 제거할 수 없는 호수에서는 응집제의 투여가 호수수질 개선의 임시적 대안으로 활용될 수 있을 것으로 보인다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.481-486
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• 2001

Ground granulated blast-furnace slag shows very high strength when proper alkali-activator exists. This paper deals with setting time, heat evolution rate and the strength development of alkali-activated slag cement activated by KOH, Ca(OH$)_{2}$, $Na_{2}$ $So_{4}$ , and alum(potassium aluminum sulfate). Alkali-activated slag mortar is studied by comparison with GGBF slag cement mortar. The experimental results indicate that for moisture curing at $25^{\circ}C$, the addiction of either 4% $Na_{2}$ $So_{4}$ or 4% alum increases the strength of GGBF slag cement mortar consisting of 50% GGBF slag and 50% portland cement at early age. Strength of activated GGBF slag cement mortars at 1, 3 and 7 days exceeded that of GGBF slag cement mortar. A conduction calorimeter was used to monitor early age hydration.

• Mycobiology
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• 제28권4호
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• pp.180-184
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• 2000

In order to find an environment-friendly method to suppress astragal stem rot caused by the isolates of Rhizoctonia solani AG 1 and AG 4, we tested an antagonistic fungus Gliocladium virens G1 was evaluated as a biocontrol agent and estimated inorganic compounds and organic materials were tested for their effect of the disease suppression. G. virens G1 effectively inhibited mycelial growth in a dual culture and caused mycelial lysis in the culture filtrate. No adverse effect was observed when examined for seed germination and seedling growth. Promoted seedling growth was observed with the seed treatment. Seeds of astragal plant were germinated higher in the sterile soil than the natural soil. Of 14 inorganics tested, alum, aluminum sulfate and calcium oxide significantly suppressed the mycelial growth and sclerotial germination. Milled pine bark and oak sawdust also suppressed the mycelial growth. Soil amended with 1% of G. virens G1 composted with pine bark (w/v) significantly controlled astragal stem rot in the glasshouse experiments.

• 한국세라믹학회지
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• 제26권3호
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• pp.361-370
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• 1989

Mullite powders were synthesized from the common solution of aluminum sulfate and sodium silicate solutions by the emulsion-hot kerosene technique. The reaction temperature and mechanism for mullitization and the characteristics of synthesized mullite powders were investigated. The effect of Na components introduced from sodium silicate solution on the physical property and microstructure of sintered mullite was also examined. It was proved that mullites were formed at 75$0^{\circ}C$ through the reaction mechanism of Na2O.2.2SiO2＋3.3Al2(SO4)3longrightarrow1.1(3Al2O3.2SiO2)＋Na2SO4＋8.9SO3. Synthetic mullite powders consisted of the compositiion of 3Al2O3.2SiO2 and showed highly agglomeration of hollow spherical particles of 1${\mu}{\textrm}{m}$ diameter. The density and fracture toughness of sintered mullites were somewhat reduced because of the effect of a very small amount of residual Na components.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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• pp.185-192
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• 1997

The combustion of cellulose insulation treated with Borax, Boric acid and Aluminum Sulfate as combustion retardants is examined by candle type combustion tester. The cellulose fibers in cellulose insulation are classified by diameter as less than 0.2mm, 0.2mm-0.5mm, 0.5mm-2mm and more than 2mm. The burning behavior of cellulose insulation are studied by LOI (Limit Oxygen Index: Beginning point of smoldering), L- point (Lower point of combustion transition from smoldering- flaming to flaming combustion), LOI, L-point and H-point rise with the increasing particle size of cellulose fibers because thermal decomposition rate of cellulose fiber decreases. The phenomena of combustion transition from smoldering to flaming combustion are determined by the generating rate of combustible gas and the formation rate of combustible gas mixture within the zone of cellulose fiber heated.

• 한국가금학회지
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• 제29권4호
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• pp.265-270
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• 2002

본 연구에서는 ALUM을 처리한 영향이 3주령과 6주령 병장아리 성장과 6주후 깔짚 중의 질소(N)함량이 어떻게 영향을 미치는지 비교시험을 하였다. 비교를 한2개 처리 구는 전부 단백질 수준을 같게 하고 한 처리구에서는 깔짚에 ALUM을 처리 하고(T$_1$) 다른 처리구에는 깔짚에 ALUM을 처리하지 않았다(T2). 이때 깔짚은 왕겨로 하였으며, ALUM 처리는 왕겨kg당 200 g을 topdressing 하였다. 사료섭취량은 22~42일령과 0~42일령에서 공히 T$_1$구가 T$_2$구보다 높았다(P<0.05). 그리고 체중증가량은 0~42일령에서 T$_1$구가 T$_2$구보다훨씬 높았으나(P<0.01) 사료효율에는 차이가 없었다. 왕겨로부터 발생되는 암모니아 농도는 처음 5주 동안은 T$_1$구가 T$_2$구보다 유의하게(P<0.05 나 P<0.01) 낮았으나 6주부터는 T$_1$구와 T$_2$구 간에는 차이가 없었다. 또 6주령에서 측정한 왕겨내의 pH는 T$_1$구가 T$_2$구보다 낮았으며P<0.05), 켈달 질소 함량(TKN)은 T$_1$구가 T$_2$구보다 높았다 (P<0.05). 그러나 왕겨내의 NH$_4$-N및 NO$_3$-N의 함량은 T$_1$과 T$_2$에서는 차이가 없었다. 본 연구 결과를 다시 정리하면 깔짚에 ALUM을 처리할 경우 6주령에서 육계의 생산성은 기대되며 암모니아 생성량의 감소는 기대하지 못하지만 깔짚은 질소비료로서의 성분은 유효함을 알 수 있다.

• Journal of the Korean Wood Science and Technology
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• 제38권3호
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• pp.230-241
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• 2010

본 연구는 산염이 첨가된 아세톤 용액으로 목질바이오매스를 가수분해하여 효과적으로 화학적 조성분을 분리할 수 있는 최적조건을 확립하는데 있다. 아세톤에 의한 목질바이오매스의 가수분해에서 $Al_2(SO_4)_3$은 우수한 촉매로 작용하였으며, 최적 농도는 0.01 M (6.3 wt%)였다. 본 실험에서는 아세톤과 물의 비율을 9 : 1로 맞추고 $Al_2(SO_4)_3$의 최적 농도조건에서 신갈나무재와 소나무재를 $200^{\circ}C$에서 45분 동안 가수분해하여 각각 92.7%와 92.4% 분해율을 나타냈다. 아세톤과 물의 비율이 8 : 2에서는 반응시간을 60분으로 연장하였을 경우 신갈나무재의 가수분해율은 92.7%였으나, 소나무재는 반응온도를 $210^{\circ}C$로 상승시켜야 신갈나무재에 버금가는 가수분해율을 얻을 수 있었다. 가수분해 온도와 시간을 증가시키면 가수분해산물로부터 분리, 회수되는 리그닌은 증가하였으나, 탄수화물 함량은 급격히 감소하는 경향을 보였다. 리그닌과 당의 회수량을 고려해 보면, 목질바이오매스의 최적 가수분해 조건은 아세톤과 물의 비율 8 : 2, 아세톤 용액에 대한 $Al_2(SO_4)_3$ 농도는 6.3 wt%, 가수분해 온도와 시간은 각각 $190^{\circ}C$와 60분으로 나타났고, 이 조건에서 당의 회수율은 목질바이오매스 전건중량 기준으로 신갈 나무재와 소나무재에서 각각 47.6%와 51.4%로 나타났고, 리그닌 회수율은 각각 18.2%와 13.7%로 측정되었다.

• 한국가금학회지
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• 제30권2호
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• pp.119-128
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• 2003

The two experiments in this study compared litter nitrogen (N) contents after broiler chicks were raised for 42 days. Experiment I compared litter treated with aluminum sulfate (alum) [Al$_2$(SO$_4$)$_3$ㆍ14$H_2O$] (T$_1$) with nontreated litter (T$_2$) when the broiler chicks were fed the same levels of dietary protein (23% for 0∼3 weeks, 21% for 4∼6 weeks) Experiment 2 compared the alum treated litters of broiler chicks fed high protein diets (T$_3$) having 20.4% protein for 0∼3 weeks and 19.3% for 4∼6 weeks, with lower protein diets (T$_4$) having protein levels of 18.0% for 0∼3 weeks and 17.0% for 4 6 weeks. Each treatment had four replicate cages. As shown in Table 1, T$_1$ had a significantly (P<0.0l) lower pH and significantly (P<0.05) higher total N (TN), NH$_4$-N and inorganic N (IN) than T$_2$. T$_1$ and T$_2$ had similar moisture, organic carbon (OC), NO$_3$-N and organic N (ON). Alum treatment increased available N (AN) significantly (P<0.05) from 13.75$\pm$0.0l mg/g to 14.90$\pm$0.01 mg/g and predicted available N (PAN) significantly (P<0.05) from 15.00$\pm$0.0l to 16.50$\pm$0.02. The C : N ratios were 18.84$\pm$0.40 (T$_1$) and 19.46$\pm$0.10 (T$_2$) while the C : ON ratios were 28.49$\pm$1.15 (T$_1$) and 28.34$\pm$0.20 (T$_2$) although C : N ratios or C : ON ratios did not show any difference between T$_1$ and T$_2$. In Table 2, T$_3$ had significantly (P<0.05) higher moisture, TN, NH$_4$-N, ON and IN than T$_4$, while the pH, OC and NO$_3$-N were similar in both groups. The AN of T$_3$ increased significantly (P<0.05) from 10.99$\pm$0.0l mg/g to 12.98$\pm$0.03 mg/g, while the PAN increased significantly (P<0.05) from 12.39$\pm$0.10 mg/g (T$_4$) to 14.68$\pm$ 0.30 mg/g (T$_3$). The C : N ratios increased significantly (P<0.0l) from 20.07$\pm$0.20 (T$_3$) to 24.40$\pm$0.10 (T$_3$). The C : ON ratios also increased significantly (P<0.0l) from 28.99$\pm$1.15 (T$_3$) to 35.51$\pm$0.20 (T$_4$). These current research results show increased AN contents and PAN contents in alum treated litter or with increased CP levels regardless of alum treatment. However, none of the litters in this study could initially increase mineralization.

• 한국재료학회지
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• 제26권12호
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• pp.733-740
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• 2016

$Al_2O_3$ nanosol dispersed under ethanol or N-Methyl-2-pyrrolidone(NMP) was studied and optimized with various dispersion factors and by utilizing the silane modification method. The two kinds of $Al_2O_3$ powders used were prepared by thermal decomposition method from aluminum ammonium sulfate$(AlNH_4(SO_4)_2)$ while controlling the calcination temperature. $Al_2O_3$ sol was prepared under ethanol solvent by using a batch-type bead mill. The dispersion properties of the $Al_2O_3$ sol have a close relationship to the dispersion factors such as the pH, the amount of acid additive(nitric acid, acetic acid), the milling time, and the size and combination of zirconia beads. Especially, $Al_2O_3$ sol added 4 wt% acetic acid was found to maintain the dispersion stability while its solid concentration increased to 15 wt%, this stability maintenance was the result of the electrostatic and steric repulsion of acetic acid molecules adsorbed on the surface of the $Al_2O_3$ particles. In order to observe the dispersion property of $Al_2O_3$ sol under NMP solvent, $Al_2O_3$ sol dispersed under ethanol solvent was modified and solvent-exchanged with N-Phenyl-(3-aminopropyl)trimethoxy silane(APTMS) through a binary solvent system. Characterization of the $Al_2O_3$ powder and the nanosol was observed by XRD, SEM, ICP, FT-IR, TGA, Particles size analysis, etc.