• Title/Summary/Keyword: Alkali

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Rheological properties of waxy-rice starches gelatinized with thermal or alkali solutions (가열 및 알칼리 호화에 의한 찹쌀 전분의 리올로지 특성)

  • Park, Yang-Kyun;Kim, Sung-Kon;Lee, Shin-Young;Kim, Kwan
    • Applied Biological Chemistry
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    • v.34 no.4
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    • pp.360-365
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    • 1991
  • Rheological properties of Shinsunchalbyeo(Japonica) and $Hangangchalbyeo(J{\times}Indica)$ waxy-rice starches gelatinized with thermal or alkali solutions were investigated with rotational viscometer(Brabender Viscotron). The two starches showed Bingham pseudoplastics behavior in $4{\sim}8%$ thermal or alkali gelatinized starch solutions. The shear stress of Hangangchalbyeo starch solution gelatinized with thermal or alkali showed higher values than that of Shinsunchalbyeo starch and the difference of the two varieties gelatinized with alkali showed higher values than that gelatinized with thermal. Consistency index and yield stress values of Hangangchalbyeo starch showed higher than that of Shinsunchalbyeo starch in the two gelatinized methods and the difference of the two varieties gelatinized with alkali showed higher values. And it was higher that the deffendence of consistency index on starch concentration and initial starch concentration of yield stress in the alkali gelatinized samples than those of in the thermal gelatinized ones.

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Petrological Characteristics of Alkali Rhyolite in the Cheonmunbong of the Mt. Baekdu (백두산 천문봉 일대 알칼리유문암의 암석학적 특징)

  • Kim, Jungsu;Yun, Sung-Hyo
    • The Journal of the Petrological Society of Korea
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    • v.26 no.3
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    • pp.183-200
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    • 2017
  • Alkali rhyolites in the Cheonmunbong of the Mt. Baekdu stratovolcano show porphyritic texture in the glassy or aphanic groundmass. Major phenocryst is alkali-feldspar, pyroxene, and amphibole, and small amount of microphenocryst is olivine, quartz, opaque mineral (ilmenite). The content of $Fe^{2+}/(Fe^{2+}+Mg^{2+})$ and alkali elements in the mafic minerals is high. Alkali feldspar is classified as sanidine or anorthclase, olivine as fayalite, and pyroxene as ferro-hedenbergite of ferro-augite area. Amphibole belongs to alkali amphibole group, but FeO and $Fe_2O_3$ were not separated, so it is required future studies. Nb(-) anomaly suggesting that slab-derived materials might have played a primary role in the genesis of the rhyolite magma, is not observed. It is noted that they originated in the within plate environment which is not related to subduction zone of the convergent plate boundary. The Mt. Baekdu alkaline rocks are classified into the comendite series. The alkali rhyolites of the summit at Mt. Baekdu shows the disequilibrium mineral assemblages, suggesting that it evolved from thrachytic magma with experience of magma mixing as well as fractional crystallization.

Strength and Pore Characteristics of Alkali-activated Slag-Red Mud Cement Mortar used Polymer According to Red Mud Content (레드머드 대체율에 따른 폴리머 혼입 알칼리활성화 슬래그-레드머드 시멘트모르타르의 강도 및 기공특성)

  • Kwon, Seung-Jun;Kang, Suk-Pyo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.20 no.2
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    • pp.26-33
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    • 2016
  • The alkali-slag-red mud(ASRC) cement belongs to clinker free cementitious material, which is made from alkali activator, blast-furnace slag(BFS) and red mud in designed proportion. This study is to investigate strength and pore characteristics of alkali-activated slag cement(NC), clinker free cementitious material, and ordinary portland cement(C) mortars using polymer according to red mud content. The results showed that the hardened alkali-activated slag-red mud cement paste was mostly consisted of C-S-H gel, being very fine in size and extremely irregular in its shape. So the hardened ASRC cement paste has lower total porosity, less portion of larger pore and more portion of smaller pore, as compared with those of hardened portland cement paste, and has higher strength within containing 10 wt.(%) of alkali-activated slag cement(NC) substituted by red mud.

Effect of Solcoseryl in Corneal Alkali Burn Rat Model

  • Kim, Hoon;Kim, Hong-Bee;Seo, Jae-Hwi;Lee, Dong Cho;Cho, Kyong Jin
    • Medical Lasers
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    • v.10 no.1
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    • pp.22-30
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    • 2021
  • Background and Objectives Ocular alkali burns cause severe damage to the ocular tissues and vision loss. Solcoseryl is a standardized calf blood extract that normalizes the metabolic disturbance and aids in maintaining the chemical and hormonal balance and has been used to treat burns in various tissues. This study examined the effects of Solcoseryl on a rat corneal alkali burn model. Materials and Methods Twenty rats were assigned randomly to four equal groups, including alkali burn, hyaluronic acid, Solcoseryl eyedrop, and Solcoseryl gel. A corneal alkali burn was induced by a NaOH-soaked paper disc. The treatments were given twice a day, every day. The wound area was measured after 24 and 48 hours, and the degree of neovascularization and corneal opacity were scored every week. The rats were sacrificed after three weeks for immunohistochemistry (IHC) to compare the level of inflammatory cytokines, IL-1β, IL-6, and TNF-α. The thickness of the retinal layers was compared to observe any changes in the retina. Results The use of Solcoseryl on corneal alkali burn accelerated wound healing with less neovascularization, greater opacity, and less cataract. IHC showed that the inflammation of the cornea was controlled by both the hyaluronic acid and Solcoseryl treatments. On the other hand, the inflammation had spread to the retina. When the dosage forms were compared, eyedrops were more effective on corneal inflammation, while the gel-type had a greater effect on retinal inflammation. Conclusion Solcoseryl was effective in accelerating the wound healing rate on a corneal alkali burn but could not prevent the spread of inflammation from the cornea to the retina. Eyedrops were more effective on inflammation in the cornea, and the gel was more effective in the retina.

Efflorescence Characteristics of Alkali-Activated Slag-Red Mud Soil Mixed Pavement of Red Mud Substitution Rate (알칼리활성화 슬래그-레드머드 흙포장재의 레드머드 대체율에 따른 백화 특성)

  • Kang, Hye Ju;Lee, Yeong;Oh, Du Yeon;Lee, Gyu Yeong;Kang, Suk Pyo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2015.11a
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    • pp.153-154
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    • 2015
  • This study is alkali-activated slag-red mud soil mixed pavement of efflorescence characteristics analysis of mitigation measures is drawn to the red mud substitution rate in accordance with the alkali-activated slag-red mud soil mixed pavement of efflorescence characteristics were exhibited. As a result of alkali-activated slag-red mud soil mixed pavement is more substitution rate increases appeared to efflorescence is increased.

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Effects of Alkali and Chloride ions on the Electric Conduction of ZrF4-Based Heavy Metal Fluoride Glasses (알칼리 및 염소 이온이 지르코늄 플루오르화물 유리의 전기전도에 미치는 영향)

  • 한택상;박순자;조운조;정기호;최상삼
    • Journal of the Korean Ceramic Society
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    • v.26 no.5
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    • pp.601-608
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    • 1989
  • Electrical properties of ZrF4-based heavy metla fluoride glasses were measured by the ac complex impedance method. The effects of alkali and chloride ions addition into fluoro zirconate glasses on the electrical conductivity were examined. The electrical conductivities of fluoride glasses show Arrhenian behavior in the temperature range of the experiment and were decreased by the addition of sodium fluoride up to 15mol%. Mixed alkali substitution resulted in conductivity minimum at intermediate composition which is commonly observed as mixed alkali effect' in alkali oxide glasses. Chloride ion substituted for fluoride ion was found to lower the conductivity.

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Removal of Pb2+ ion from aqueous solution Using crab shell treated by acid and alkali (산-염기 처리한 게 껍질에 의한 수풍의 납 이온 제거)

  • 김동석
    • Journal of Environmental Science International
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    • v.12 no.4
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    • pp.469-476
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    • 2003
  • In order to examine the pre-treatment effect of crab shell en Pb$^{2+}$ removal by crab shell in aqueous solution, acid and alkali pre-treated crab shell were used. Electron microscopy techniques such as TEM (transmission electron microscopy) and SEM (scanning electron microscopy), and EDX (energy dispersive X-ray) and FTIR (Fourier transform infrared) spectrometry techniques were used to investigate the process of Pb$^{2+}$ removal by acid and alkali pre-treated crab shell. The Pb$^{2+}$ removal by acid pre-treated crab shell was much lower than that by untreated crab shell because of the decrease of CaCO$_3$ from the crab shell. However, the Pb$^{2+}$removal by alkali pre-treated crab shell increased compared to that by untreated crab shell. The results were confirmed by TEM, SEM, EDX and FTIR.nd FTIR.

Premature Stiffening of Cement Paste Associated with AFm Formation

  • Chung, Chul-Woo;Lee, Jae-Yong
    • Journal of the Korea Institute of Building Construction
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    • v.11 no.1
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    • pp.83-90
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    • 2011
  • The purpose of this research is to investigate the effect of AFm formation on the stiffening process of cement paste. High and low alkali sulfate clinkers were used for the experiments. The flow and stiffening behavior of cement paste was investigated using modified ASTM C403 penetration resistance test and oscillatory shear rheology. X-ray powder diffraction (XRD) was used for phase identification associated with stiffening of the paste. It was found from the results that low alkali clinker mixture produced very strong premature stiffening whereas high alkali clinker mixture did not cause premature stiffening. This is because of the large amount of alkali sulfate present in the clinker. Addition of calcium and sodium chloride to the high alkali clinker mixture caused faster stiffening and set.

Alkali-Swollen Morphology of Native Cellulose Fibers

  • Kim, Nam-Hun
    • Journal of the Korean Wood Science and Technology
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    • v.35 no.2
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    • pp.16-22
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    • 2007
  • The behavior of ramie fibers and some wood elements in the early stage of alkali swelling was examined. When the fibers were treated with alkali solution, they significantly shrank in length and swelled in wall thickness. Ramie fibers showed a shrinkage averaging 23% in length and a swelling averaging 92% in width in 100 seconds treating time. Dimensional changes showed different fashion in each element of woods. The tracheids of latewood especially in Pinus densiflora and Larix kaempferi woods swelled intensively and showed balloon swelling, but in the case of Cryptomeria japonica, it was hardly observed. The swelling morphology of libriform fibers was similar to that of tracheids. The walls of vessel elements and parenchyma cells also swelled considerably in thickness but, no balloon swelling was found in both elements. The differences of swelling in different elements can be interpreted in terms of the differences of organization and/or chemical components of the cell walls.

Morphological and Physicochemical Changes of NBKP by Alkali Pretreatment (알카리 전처리에 의한 NBKP의 형태학적 및 이화학적 변화)

  • Mun, Sung-Phil;Jang, Min-Hwan
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.41 no.4
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    • pp.58-64
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    • 2009
  • This study was carried out to prepare high porosity pulp for oil and air filter media from commercial grade NBKP with 6 - 20% NaOH treatment. The fiber width of NBKP remarkably decreased by NaOH pretreatment. The air permeability of the test sheet prepared from alkali-pretreated NBKP increased with increasing NaOH concentration up to 15%. The burst factor was greatly decreased by alkali pretreatment. By 15 - 20% NaOH pretreatment of NBKP, it could be possible to prepare a high porosity pulp. It seems that the high porosity of the pulp was due to a strong swelling and a great change of the cellulose crystalline lattice from cellulose I to cellulose II with NaOH treatment of NBKP. The study suggested that alkali- pretreated NBKP could be used for manufacturing oil and air filter media.