• Animal Bioscience
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• 제36권5호
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• pp.818-828
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• 2023

Objective: The purpose of this study was to analyze the effect of the hydrothermal pretreatment of anaerobic digestion sludge cake (ADSC) of cattle manure on the solubilization of organic matter and the methane yield to improve the anaerobic digestion efficiency of cattle manure collected from the sawdust pens of cattle. Methods: Anaerobic digestion sludge cake of cattle manure was thermally pretreated at 160℃, 180℃, 200℃, and 220℃ by a hydrothermal pressure reactor, and the biochemical methane potential of ADSC hydrolysate was analyzed. Methane yield recovered by the hydrothermal pretreatment of ADCS was estimated based on mass balance. Results: The chemical oxygen demand solubilization degree (COD_s) of the hydrothermal hydrolysate increased to 63.56%, 67.13%, 70.07%, and 66.14% at the hydrothermal reaction temperatures of 160℃, 180℃, 200℃, and 220℃, respectively. Considering the volatile solids content obtained after the hydrothermal pretreatment, the methane of 10.2 Nm³/ton-ADSC was recovered from ADSC of 1.0 ton, and methane yields of ADSC hydrolysate increased to 15.6, 18.0, 17.4, and 17.2 Nm³/ton-ADSC. Conclusion: Therefore, the optimal hydrothermal reaction temperature that yielded the maximum methane yield was 180℃ based on mass balance, and the methane yield from cattle manure containing sawdust was improved by the hydrothermal pretreatment of ADSC.

• 한국결정성장학회지
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• 제6권2호
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• pp.254-262
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• 1996

수열합성법을 이용하여 $1~3\;\mu\textrm{m}$의 입자 크기를 갖는 균일한 $Pb(Zr_{0.52}Ti_{0.48})O_{3}$ (PZT)분말을 제조하였다. 출발물질의 종류에 따라 반응조건이 다소 차이를 보였지만, 일반적으로 10 M의 KOH를 광화제로 사용하여, $180^{\circ}C$ 이상에서 2시간 동안 반응시켜 PZT 분말을 합성 할 수 있었다. 또한, 광화제의 농도, 수열반응 온도, 그리고 반응시간이 증가할수록 균일상의 분말이 형성됨을 보였다.

• 한국세라믹학회지
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• 제35권10호
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• pp.1030-1039
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• 1998

In fly ash-lime system the effects of reaction condition amounts of gypsum and cement and CaO/SiO2 ratio on the hydrates by hydrothermal reaction were investigated. The tobermorite phases were not observed in hy-drothermal reaction of fly ash lime because of the hydrate rate was very slow. The compressive strength and the hydration rate increased with increasing the amount of gypusm and cement and the optimum amounts of gypsumo and cement were 5wt and 20wt% respectively. The specimen which CaO/SiO2 ratio is 0.85 was shown the maximum compressive strength and the tobermorite phase within reaction time 2 hours.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.420-421
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• 2005

$LiMnPO_4$ particle were prepare by a hydrothermal reaction. The particles prepared by adding polyethylene glycol(PEG) and carbon to the starting reaction solution were fine crystalline in the range of 200-300nm. The discharge capacity of the sample as a lithium secondary battery was $25mAhg^{-1}$ at $0.04mAcm^{-2}$, larger than that of the sample prepared by the hydrothermal method without PEG and carbon.

• 한국재료학회지
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• 제34권2호
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• pp.79-84
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• 2024

Thin films of yttria-stabilized zirconia (YSZ) nanoparticles were prepared using a low-temperature deposition and crystallization process involving successive ionic layer adsorption and reaction (SILAR) or SILAR-Air spray Plus (SILAR-A+) methods, coupled with hydrothermal (175 ℃) and furnace (500 ℃) post-annealing. The annealed YSZ films resulted in crystalline products, and their phases of monoclinic, tetragonal, and cubic were categorized through X-ray diffraction analysis. The morphologies of the as-prepared films, fabricated by SILAR and SILAR-A+ processes, including hydrothermal dehydration and annealing, were characterized by the degree of surface cracking using scanning electron microscopy images. Additionally, the thicknesses of the YSZ thin films were compared by removing diffusion layers such as spectator anions and water accumulated during the air spray plus process. Crack-free YSZ thin films were successfully fabricated on glass substrates using the SILAR-A+ method, followed by hydrothermal and furnace annealing, making them suitable for application in solid oxide fuel cells.

• International Journal of Concrete Structures and Materials
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• 제10권1호
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• pp.15-28
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• 2016

With the aim to reduce the atmospheric $CO_2$, utilization of the carbonated lime produced from the aqueous carbonation reaction for the synthesis of a cementitious material would be a promising approach. The present investigation deals with the aqueous carbonation of slaked lime, followed by hydrothermal synthesis of a cementitious material utilizing the carbonated lime, silica fume, and hydrated alumina. In this study, the aqueous carbonation reaction was performed under four different conditions. The TGA, FESEM, and XRD analysis of the carbonated product obtained from the four different reaction conditions was performed to evaluate the efficacy of the reaction conditions used for the production of the carbonated lime. Additionally, the performance of the cementitious material was verified analyzing the physical characteristics, mechanical property and setting time. Based on the results, it is demonstrated that the material produced by the hydrothermal method possesses the cementing ability. Additionally, it is revealed that the mortar prepared using the alternative cementitious material yields $33.8{\pm}1.3MPa$ compressive strength. Finally, a plausible reaction scheme has been proposed to explain the overall performances of the aqueous carbonation as well as the hydrothermal synthesis of the cementitious material.

• 한국재료학회지
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• 제15권12호
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• pp.818-823
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• 2005

Sub-micron colloidal silica particles coated with nano-sized ceria were prepared by mixing of its silica and cerium salts hydrolysis, and modified by hydrothermal reaction. By using the slurries with and without hydrothermal modification containing above particles, oxide film coated on silicon wafer was polished. The modified slurries had higher polish rate due to increase of ceria fraction to silica through hydrothermal reaction. They revealed higher stability in wide range of pH $2\~10$ than ceria coated silica slurries without its modification.

• Bulletin of the Korean Chemical Society
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• 제31권8호
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• pp.2368-2370
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• 2010

• 한국세라믹학회지
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• 제29권12호
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• pp.997-1003
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• 1992

Ultra-fine hydroxyapatite powders were synthesized by the hydrothermal reaction of Ca(OH)2 suspension or Ca(NO3)2$.$4H2O solution with (NH4)2HPO4 solution, and the powders were characterized for each synthetic condition. Crystalline hydroxyapatite powders have average grain size of less than 50 nm. By increasing the reaction pressure, the crystallinity was improved, and the crystals were preferentially growing along c-axis. When Ca(NO3)2$.$4H2O of high solubility was used, hydroxyapatite of single phase was produced. However when Ca(OH)2 of low solubility was used more than 0.334 mol/ι, unreacted Ca(OH)2 remained. Diffraction spot patterns of transmission electron microscope show that powders synthesized by the hydrothermal reaction were composed of single crystals of hexagonal phase.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1985년도 하계학술회의논문집
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• pp.191-193
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• 1985

Reaction temperature md piezoelectric properties of Pb(Mn1/3 Sb2/3)0.08 Ti0.495 Zr0.425 $O_3$ ceramics by hydrothermal synthesis method have been investigated. Sintering density and dielectric constant of sample increased with increasing of hydrothermal reaction temperature, while decreased rapidly above $240^{\circ}C$. Electromechanical coupling factor kp was almost constant at the reaction temperature $160^{\circ}-240^{\circ}C$.