• Title/Summary/Keyword: hydration treatment

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Surface Modification of MgO Microcrystals by Cycles of Hydration-Dehydration

  • 김해진;강진;송미영;박선회;박동곤;권호진;남상성
    • Bulletin of the Korean Chemical Society
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    • v.20 no.7
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    • pp.786-790
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    • 1999
  • Relatively inert surface of microcrystalline MgO was modified into chemically active one by carrying out controlled hydration followed by dehydration at elevated temperature under dynamic vacuum. Even though the treatment by the first cycle of hydration-dehydration did not alter the porosity of MgO, it largely enhanced surface reactivity of the MgO toward adsorbed water, turning its outer layer into brucite upon rehydration. Treatment by the second cycle of hydration-dehydration generated micropores, and slit-shaped mesopores, raising the porosity of the MgO. The overlayer of Fe2O3 of the core/shell type composite magnesium oxide enhanced this surface modification, turning its surface into more porous and more active one than that of uncoated MgO, after the treatment by the hydration-dehydration.

Effect of Controlled Hydration on Germination of Tobacco Seeds

  • Min, Tai-Gi;Yoon, Hyo-Jung
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.48 no.4
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    • pp.322-325
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    • 2003
  • Controlled hydration treatment of tobacco seeds enhanced seed performance greatly without additional materials associated with conventional osmotic or solid matrix priming technique. The seeds were hydrated by adding water to a level from 10 to 60% by 5% increments and incubated for 8 days at $25^{\circ}C$. After the treatment, the seeds were dried to the original seed moisture content under $20^{\circ}C$ for 72 hours. The moisture content of tobacco seeds equivalent to 35% by the hydration treatment gave the greatest improvement in germination rate and speed compared to untreated or polyethylene glycol (PEG) primed seeds, especially at low temperature of $15^{\circ}C$.

Effect of Aromatherapy on Skin Xerosis and Pruritus in Patients Undergoing Maintenance Hemodialysis (향 요법이 혈액투석 환자의 피부건조와 소양증에 미치는 효과)

  • 하혜정
    • Journal of Korean Academy of Nursing
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    • v.29 no.6
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    • pp.1284-1293
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    • 1999
  • This study was designed to investigate the effect of aromatherapy on skin xerosis and pruritus in patients undergoing maintenance hemodialysis. Twenty one subjects of this study were selected from St. Paul's Hosipital in Seoul. All the subjects were received the mineral oil massage at the arm without fistular three timesper week for 4 weeks. After 2 weeks period of wash-out, the subjects were received the aromatherapy of lavender and tea tree essence oil in the same way. This study was carried out from March 20 to June 13, 1998. Pruritus score, skin pH and stratum corneum hydration were measured before and after each treatment. But, biochemical parameters were measured before the treatment of the mineral oil massage, after the treatment of the mineral oil massage and the aromatherapy. Data of this study were analyzed by paired t-test, repeated measures ANOVA, Bonferroni multiple comparisons and Pearson correlation coefficient. The results were as follows ; 1. Pruritus score was significantly decreased after the aromatherapy, while no significant change after the treatment of the mineral oil massage. Therefore, there was a significant difference in the priritus score between the two treatments. 2. Stratum corneum hydration was significantly increased after the aromatherapy, while no significant change after the treatment of the mineral oil massage. Therefore, there was a significant difference in the stratum corneum hydration between the two treatments. 3. Skin pH was significantly increased after the treatment of the mineral oil massage, while no significant change after the aromatherapy. Therefore, there was no significant difference in the skin pH between the two treatments.4. After the aromatherapy, the serum calcium was significantly increased. Whereas the serum parathyroid hormone intact was significantly decreased compared with the treatment of the mineral oil massage. But the level of the serum Ca and PTH-intact were within the normal range. 5. Stratum corneum hydration was decreased corresponding to the duration of hemodialysis, while pruritus score and skin pH showed no change corresponding to the duration of hemodialysis and the age of the subjects. The correlation of pruritus score on skin pH, stratum corneum hydration and biochemical parameters was not significant. In conclusion, this findings indicate that aromatherapy may be effective in decreasing skin xerosis and pruritus score in uremic pruritus patients undergoing maintenance hemodialysis.

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Dispersion Effect of Hydration Heat in Mass Concrete Using Embedded Heat Pipe (매입형 히트파이프를 이용한 매스콘크리트 수화열 분산 효과)

  • Kim, Myung-Sik;Youm, Chi-Sun;Baek, Dong-Il
    • Journal of Ocean Engineering and Technology
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    • v.23 no.4
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    • pp.85-90
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    • 2009
  • Although most of existing hydration heat control methods show a certain degree of hydration heat control, generally, there are many problems as mentioned above. Therefore, our laboratory previously developed a hydration heat control method using an exposed heat pipe, which solves most of these problems and simultaneously displays excellent hydration heat control. Unfortunately, even this method had some problems such as the processing, transport, and assembly of heat pipes, and the surface treatment of a cut plane after pouring, and hardening concrete. Therefore, in this study, a hydration heat control method using an embedded pipe has been developed with the expectation that this method solves those problems in hydration heat control using an exposed heat pipe. As a result of the experiment, the peak temperature of ECHP and ICHP specimen about $4.5{\sim}6.5^{\circ}C$ than the OPC specimen and the probability of thermal cracked generated in ECHP and ICHP specimen decreased up to $13{\sim}20%$. Finally, it was confirmed in this study that the hydration heat control method using an embedded heat pipe is significantly more superior and cost effective than the existing method of an exposed one.

A Clinical Study for the Efficacy and Safety of Functional Cosmetics Containing Humulus japonicus Extract in Patients with Dry Skin due to Mild Atopic Dermatitis (아토피성 피부로 건조함을 가진 대상자에 대한 환삼덩굴추출물 함유 기능성 화장품의 유효성 및 안전성을 평가하기 위한 임상적 연구)

  • Park, Hye-Su;Kim, Yong-Min;Kim, Hee-Tack
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.32 no.2
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    • pp.24-58
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    • 2019
  • Objectives : The purpose of this study is to confirm the Efficacy and Safety of "Functional cosmetics containing Humulus japonicus Extract" on dry skin due to mild atopic dermatitis. Methods : A total of 48 patients who visited Semyung Oriental Medical Center from March 20th, 2018 to July 5th, 2018 were included in the study. In this study, the patients were treated with Functional cosmetics containing Humulus japonicus Extract and positive control group. For 6 weeks of gross examination, instrumental assessment were made before and after the study to evaluate how well the products for treatment group with positive control products for control group in recovering the dry skin barriers by mild atopic dermatitis. Results : 1. In the primary endpoint, Skin Hydration showed a statistically significant increase and Transepidermal Water Loss(TEWL) showed a statistically significant decrease in treatment group between Baseline and 6 weeks. 2. In the secondary endpoint, Skin Hydration showed a statistically significant increase in treatment group between Baseline and 3 weeks, but TEWL showed no statistical significance. 3. In the secondary endpoint, Skin Hydration showed a statistically significant increase in treatment group between 3 weeks and 6 weeks, but TEWL showed no statistical significance. 4. In the secondary endpoint, Change of Skin Hydration and TEWL between treatment and control group showed a statistical significance in 6 weeks. 5. In the secondary endpoint, Change of Skin Hydration of 1cm below the medial aspect of the elbow between treatment and control group showed a statistical significance in 3 weeks. 6. In the secondary endpoint, Change of Skin Hydration between treatment and control group showed a statistical significance in 3 weeks and 6 weeks except Center between the medial aspect of the elbow and the wrist in 3 weeks, and Change of TEWL between treatment and control group showed a statistical significance in 6 weeks. 7. To evaluate the safety of the products for the human body, Adverse events, EASI Score, Itching Symptoms Assessment, vital sign check were conducted; There were no severe adverse events during this study. And both experimental group and control group showed no abnormal level. Therefore, it is suggested that products, if used for certain period, should be safe for the human body. Conclusions : According to the above experiments, it is suggested that "Functional cosmetics containing Humulus japonicus Extract" should be effective for dry skin due to mild atopic dermatitis.

Hydration Properties of Cement Matrix using Surface Treatment Blast Furnace Slag by Arc Discharge (아크방전에 의해 표면개질 된 고로슬래그를 사용한 시멘트 경화체의 수화 특성)

  • Kim, Sun-A;Kim, Hyeon-Sung;Park, Sun-Gyu
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.05a
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    • pp.91-92
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    • 2018
  • A glassy thin film was formed on the surface of the blast furnace slag. When blast furnace slag is used as an admixture of concrete, addition of alkali activators were required. However, alkali activators are not only dangerous as chemical products, but they are also difficult to use as expensive materials. Therefore, it is necessary to study the way of removal of the glassy thin film of blast furnace slag without the risk and cost increase. In this study, to solve this problem, experiment was carried out to improve the hydration reactivity by treatment the surface of blast furnace slag using arc discharge. Experimental results show that when the surface of the blast furnace slag was tratmented by arc discharge, the glassy thin film was destroyed. And the hydration reactivity was improved, the compressive strength was increased.

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Effects of Hydration Treatments on the Phase Transition of Anodic Aluminum Oxide Layers (알루미늄 양극산화 피막의 상전이에 미치는 수화처리의 영향)

  • Joo, E.K.;Kim, S.S.;Oh, H.J.;Cho, S.H.;Chi, C.S.
    • Korean Journal of Materials Research
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    • v.12 no.7
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    • pp.540-544
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    • 2002
  • Hydration treatments were performed on the pure aluminum substrate at $100^{\circ}C$ followed by anodizing and heat treatments on the layers. The transformation behaviors of the oxide layers according to the hydration treatment were studied using TEM, XRD, RBS etc. Above $90^{\circ}C$ the hydrous oxide film could be formed, which were turned out to be hydrous oxides(AlOOH $nH_2$O). The anodization on the hydrous oxide film was more effective for the transition of amorphous anodic oxides to the crystalline $\Upsilon-Al_2$ $O_3$ comparing with the case for anodizing on the aluminum substrate without hydration treatment And additional heat treatments were also helpful for the acceleration of the transformation of the hydrous oxide to $\Upsilon-Al_2$ $O_3$. During the heat treatment the interface between $\Upsilon-Al_2$ $O_3$and the hydrous oxide layers migrated to the outer side of hydrous layer.

Cement/PVDF hollow-fiber hybrid basement membrane: Preparation, microstructure, and separation application

  • Yabin, Zhang;Xiongfei, Du;Taotao, Zhao
    • Membrane and Water Treatment
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    • v.13 no.6
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    • pp.291-301
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    • 2022
  • In this study, cement/PVDF hollow-fiber hybrid membranes were prepared via a mixed process of diffusion-induced phase separation and hydration. The presence of X-ray diffraction peaks of Ca(OH)2, an AFt phase, an AFm phase, and C-S-H phase confirmed the hydration reaction. Good hydrophilicity was obtained. The cross-sectional and surface morphologies of the hybrid membranes showed that an asymmetric pore structure was formed. Hydration products comprising parallel plates of Ca(OH)2, fibrous ettringite AFt, and granulated particles AFm were obtained gradually. For the hybrid membranes cured for different time, the pore-size distribution was similar but the porosity decreased because of blocking of the hydration products. In addition, the water flux decreased with hydration time, and carbon retention was 90% after 5 h of rejection treatment. Almost all the Zn2+ ions were adsorbed by the hybrid membrane. The above results proved that the obtained membrane could be alternative as basement membrane for separation application.

Effect of Pretreatment on the Dissolution of Aluminum Alloy during Hydration Process (수화과정에서 전처리가 알루미늄 합금의 용출에 미치는 효과)

  • Lee, Byoung-Gu;Lee, Hoyeon;Tak, Yongsug
    • Corrosion Science and Technology
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    • v.12 no.5
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    • pp.215-219
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    • 2013
  • Aluminum alloy(3003) can be dissolved during hydration process with hot tap water. In order to increase the stability of aluminum alloy, it was pretreated with anodization and phosphoric acid before hydration process. The effect of pretreatment on the surface property changes was analyzed with X-ray Photoelectron Spectroscopy (XPS) and Inductively Coupled Plasma-Optical Emission Spectrometer (ICP-OES) and their results supported that the increase of hydroxyl group (-OH) on the surface formed during anodization and phosphorous acid treatment prevented the dissolution of aluminum alloy during hydration process at high temperature.

Re-hydration of Heat-treated $CaO-SiO_2-H_2O$ System and Their Application under Hydrothermal Condition (열처리한 $CaO-SiO_2-H_2O$계의 수열반응과 이의 응용에 관한 연구)

  • 윤철현;송태웅
    • Journal of the Korean Ceramic Society
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    • v.31 no.11
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    • pp.1387-1395
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    • 1994
  • Re-hydration properties of heated and ground CaO-SiO2-H2O system were studied under hydrothermal condition in order to examine the possibility of recycling ALC waste as raw materials of ALC. Powder of calcium silicate hydrates and ALC waste without heat treatment did not show further hydration while those of heat-treated at proper temperature showed re-hydration properties under hydrothermal condition. The lath-like shape of initially synthesized tobermorite was gradually turned into small debris during heating and plate-like tobermorite was crystallized during re-hydration of the heated powders. Heated and ground ALC waste could be added to natural raw mix for ALC at the ammount up to 20% with increased compressive strength and up to 30% with slightly decreased compressive strength. The optimum heating temperature of ALC for recycling was about 50$0^{\circ}C$.

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