• Asian-Australasian Journal of Animal Sciences
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• 제16권3호
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• pp.368-373
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• 2003

This experiment was conducted to examine the effects on the composition and rumen degradation in sacco of rice straw treated with animal urine (1 l of 2.9 g N/kg DM straw) and urea plus calcium hydroxide (2% urea plus 0.5% $Ca(OH)_2$/kg DM straw) as a cheap and relatively safe alternative for ammonia (3% ammonia solution/kg DM straw). Mold occurred in urine treated straw, but other treatments were apparently mold-free. All treatments significantly (p<0.05) increased CP content in the straw compared with untreated one. Ammonia-treated straw contained CP at about twice that in urine or urea-calcium hydroxide treated straw. NDF and hemicellulose contents decreased significantly (p<0.05) in all treatments, while ADF and cellulose showed no differences compared with untreated straw. The degradable fraction of DM, CP, NDF, hemicellulose and cellulose was significantly (p<0.05) increased for ammonia and urea-calcium hydroxide treatments than for urine treated or untreated straw except for CP of urine treated straw. Chemical treatment of rice straw increased the readily degradable fraction of CP, while it decreased the slowly degradable fraction for urine or urea-calcium hydroxide treated rice straw. The degradation rate of hemicellulose was significantly (p<0.05) increased for ammonia and urea-calcium hydroxide treatments compared to urine treated or untreated straw. However, no effect on cellulose degradation rate was found by any of the treatments. There was no improvement in the degradation kinetics caused by the urine treatment despite the improvement of the chemical composition. Although the improvement in rumen degradability was less in the urea-calcium hydroxide treatment than in the ammonia treatment, its use may be more desirable because it is less expensive to obtain, less hazardous nature, and readily available. For further improvement it is necessary to investigate the supplementation of slowly degradable nitrogen to ureacalcium hydroxide treated rice straw diet.

• Restorative Dentistry and Endodontics
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• 제26권2호
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• pp.111-120
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• 2001

Calcium hydroxide pastes is widely used in conventional endodontics. Along with the expanded clinical use of calcium hydroxide, literatures suggest mixing calcium hydroxide with other substance. Among added substances the vehicle plays the most importance role in the overall process because it is directly related with the velocity of ionic dissociation of $Ca^{2+}$ and OH ion. In this study, we evalutated and compared periapical tissue response and root resorption after canal was filled with mixture of saline and calcium hydroxide(Junsei Chemical Co.. Japan) as a aqueous vehicle, Metapaste(Meta Co., Korea) as a viscous vehicle paste, Vitapex(Neo Dental, Japan) as a oily vehicle paste and IRM(Caulk Dentsply, USA) in replantation of rat molar. A total of 31 maxillary first molars of Sprague-Dawley female rats, 30 days old were used. The upper 1st molar was extracted and the mesiobuccal canal was filled with mixture of saline and calcium hydroxide, Metapaste, Vitapex. IRM and then replanted. Rats were sacrificed 3 weeks after replantation. the maxillae were removed. section of 4 micron were cut and stained with hematoxylin-eosin, Apical tissue response were observed under light microscope. The results were as follows: 1. Saline mixing group and Metapaste group were significant different in fibrous capsule width compared to Vitapex group and IRM group(P<0.05). 2. Saline mixing group. Metapaste group. Vitapex group and IRM group did not prevent root resorption and there were no statistical difference. 3. In saline mixing group and Metapaste group. loss of pastes were observed in all samples. From the results of our study. we observed loss of pastes in saline mixing group and Metapaste group because of water soluble property and assumed it was related to inflammation in apical area and sealing ability of material. So, we should study and develop calcium hydroxide vehicle which is easily removed and more stable and because of only 3 weeks observation we need more evaluation in long period.

• 한국약용작물학회지
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• 제23권2호
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• pp.150-154
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• 2015

Physiological disorders such as symptoms in leaf colored with brown spots are so many occurred in ginseng garden cultivated with paddy soil. This study was carried out to inhibit the symptoms of brown-colored leaf in 3-year-old ginseng by fertilizing calcium hydroxide [$Ca(OH)_2$] of 100 ~ 400 kg per 10a on paddy soil before transplant of seedling. Soil pH was rapidly increased, while Fe was decreased in soil by the increase of application level of calcium hydroxide. Soil pH was increased from 4.53 to 6.18 when calcium hydroxide was fertilized at level of 100kg per 10a. The content of Fe in ginseng leaf was decreased more than the control by fertilizing calcium hydroxide in soil. Ratio of brown-colored leaf and plant height and leaf area were decreased by the increase of calcium hydroxide. Ratio of survived root and yield of root showed the peak at the application level of 100 kg per 10a, and both of them were gradually decreased by the increase of calcium hydroxide. The decrease of missing plant rate above the application level of 200 kg per 10a had a negative effect on the decrease of yield of root.

• 공업화학
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• 제22권4호
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• pp.439-443
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• 2011

수산화마그네슘이 첨가된 저밀도 폴리에틸렌-에틸렌 비닐 아세테이트 혼합물의 연소성을 시험하였다. 저밀도 폴리에틸렌-에틸렌 비닐 아세테이트에 수산화마그네슘을 40~80 wt% 첨가하여 용융 혼합하고 성형 후 콘칼로리미터(ISO 5660-1)를 이용하여 그의 연소성을 시험하였다. 수산화마그네슘을 첨가한 시험편은 첨가하지 않은 시험편에 비하여 그의 연소성이 감소하였다. 이것은 순수한 저밀도 폴리에틸렌-에틸렌 비닐 아세테이트에 첨가한 수산화마그네슘의 흡열 분해 때문에 연소 억제성이 향상된 것으로 생각된다. 수산화마그네슘을 첨가한 시험편은 첨가하지 않은 시험편에 비해 낮은 최대열방출률과 낮은 유효연소열을 나타내었고, 수산화마그네슘 함량이 증가할수록 착화시간은 길어지고, 최대열방출률은 감소하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.142.1-142.1
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• 2016

We present bulk diffusion rates of hydroxide ions in amorphous solid water (ASW) at 135 ~ 160 K. Previous researches showed that the diffusion mechanism of hydroxide is different from one of hydronium ions, and this implies that they have different diffusion rates. In ultra-high vacuum (UHV) chamber, low-energy scattering (LES) was used to measure ion population and temperature-programmed desorption (TPD) was conducted for measuring ASW thicknesses. To determine the diffusion rates, a simple model for $H_2O/NaOH/H_2O$ sandwich films was developed using Fick's second law. The measured surface population of hydroxide ions as a function of time was well fitted to the model, and the rates were well agreed to an Arrhenius equation.

• 한국응용과학기술학회지
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• 제26권4호
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• pp.385-393
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• 2009

Different types magnesium hydroxide groups have been obtained using the hydrothermal precipitation technique from magnesium sulfate and calcium carbonate solution. The Mg atom coordinated around O atom of ${SO_4}^{2-}$ in another layer to form a multi-layer structure crystal. The influence of synthesis parameters on the morphological characteristics and size of magnesium hydroxide groups precipitated in aqueous were investigated such as different of additive and pH. Magnesium hydroxide groups were decomposed gradually and converted finally to MgO particles after heated in air temperature up to $1050^{\circ}C$. The particle size and it's distribution morphology, crystal phase and thermal behavior of the samples were characterized through XRD, SEM, EDS, and TG/DTA.

• Rapid Communication in Photoscience
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• 제4권2호
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• pp.34-36
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• 2015

New spectroscopic characteristics of amorphous ferric hydroxide ($Fe(OH)_3$), interestingly in the near infrared (NIR) region, are presented in this study. The absorption spectrum of ferric hydroxide covers wide spectral regions from ultraviolet to NIR (200~900 nm). Unique emission bands were newly observed in the NIR regions (800~1400 nm). Several bands of this NIR emission are quiet well overlapped with the combinational vibrational absorption bands of water. From photothermal conversion study, very interestingly, temperature of aqueous mixture solution including the amorphous ferric hydroxide was significantly increased from ambient temperature to $38^{\circ}C$ for 30 minutes under irradiation of a standard helium lamp.

• Asian-Australasian Journal of Animal Sciences
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• 제1권2호
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• pp.65-71
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• 1988

This study reports light and electron microscope examination of rumen fungal colonization of alkali-treated roughage feeds incubated in decron bags in the rumen of cannulated sheep for varying time intervals. Six roughages, pre-treated with ammonium hydroxide or sodium hydroxide at 4% (w/w) level were examined together with untreated control samples. Alkali pre-treatment was associated with an earlier and more pronounced fungal colonization than all control roughages. Sodium hydroxide pre-treatment was significantly more effective than ammonium hydroxide in improving the susceptibility of roughages to rumen fungal colonization and studies by SEM showed that the pre-treatment permitted greater penetration of feeds by fungi. Sodium hydroxide pre-treatment also significantly increased dry matter disappearance from feed held in Dacron bags in the rumen with all feeds except Lucerne stem. It is not known to what extent fungal activity contributed to increased breakdown of the feeds.

• Restorative Dentistry and Endodontics
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• 제11권1호
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• pp.19-25
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• 1985

To compare calcium hydroxide with Vitapex paste in the effect of apical closure, apexification was done with two medicaments in the nine teeth of seven patients visiting at SNUDH, and then, after radiographic and clinical observation of at least six months, the author concluded the followings: 1. The significant differences between calcium hydroxide and Vitapex paste were not observed in the effect of apical closure. 2. In calcium hydroxide group, the resorption of the paste within the canal was not observed, but in Vitapex group, observed. 3. In both calcium hydroxide group and Vitapex group, the progressive healing of apical lesion was observed. 4. The progressive resorption of Vitapex paste out of the apical foramen was observed.

• Macromolecular Research
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• 제17권6호
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• pp.397-402
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• 2009

In emulsifier-free, emulsion polymerization with ionizable comonomer, the ionization of the comonomer is critical in determining the size of the final polymerie particles at sub-micrometer scale. In this study, polystyrene latex beads with carboxylates on the surface were synthesized using acrylic acid as a comonomer. Specifically, ammonium hydroxide was added to the emulsifier-free polymerization system to promote the ionization of acrylic acid by increasing pH. Smaller polystyrene latex particles were produced by increasing the ammonium hydroxide concentration in the reaction system, due to the enhanced stability promoted by the ionization of acrylic acid during the nucleation step. In addition, the surface morphology of the polystyrene latex particles was controlled by the concentration of acrylic acid, the dissociation of which was influenced by the ammonium hydroxide concentration.