• Title/Summary/Keyword: Acidic Properties

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Histochemistry of Mucosubstances on the Pedal Sole of Five Abalone Species

  • Chu Lee;Dae Yeon Moon;Young Ju Lee;Byung Tae Choi
    • Animal cells and systems
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    • v.3 no.3
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    • pp.253-258
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    • 1999
  • The present study describes histochemical properties of the mucosubstances in the pedal sole of abalone, in relation to two main additional functions known to date. Only neutral mucosubstances were demonstrated in the lateral epithelium of the pedal sole of the abalone, however, two distinct types of cells, one containing neutral and the other containing acidic mucosubstances, were identified in the ventral epithelium. The epithelial mucocytes distributed throughout both epithelial and subepithelial glands located in the ventral subepithelial region showed a mixture of neutral and acidic mucosubstances. However, acidic mucosubstances were found in larger amounts than neutral ones in epithelial mucocytes, and vice versa in subepithelial glands. Among these acidic mucosubstances, sulphated substances were dominant. Lesser amounts of carboxylated substances also occurred together with low levels of neuramic and sialic acid. Collectively, the notable morphological differences between abalone and other gastropoda were observed in the ventral surface of the foot, which showed a tall columnar epithelium, peripherally concentrated mucocytes, and subepithelial glands. Mucosubstances are presumably produced by these cells and may also play a role in clinging to some substances to support abalones in addition to the main functions of lubrication and protection.

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Effects of extrusion cooking on physicochemical properties of white and red ginseng (powder)

  • Gui, Ying;Ryu, Gi-Hyung
    • Journal of Ginseng Research
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    • v.38 no.2
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    • pp.146-153
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    • 2014
  • A systematic comparison of the physicochemical properties of white ginseng (WG), extruded white ginseng (EWG), red ginseng (RG), and extruded red ginseng (ERG) was performed. The aim of the present study was to identify the effects of the physicochemical properties of ginseng by extrusion cooking. The highest value of the water absorption index (WAI) was 3.64 g/g obtained from EWG, and the highest value of the water solubility index (WSI) was 45.27% obtained from ERG. The ERG had a better dispersibility compared with other samples. Extrusion cooking led to a significant increase in acidic polysaccharide and total sugar content but resulted in a decrease in crude fat and reducing sugar contents. Enzyme treatment led to a sharp increase in acidic polysaccharide content, especially the cellulose enzyme. Extrusion cooking led to a significant increase in 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and reducing power, and the increases in WG and RG were 13.56% (0.038) and 3.56% (0.026), respectively. The data of this study provide valuable information about the effects of extrusion on quality changes of EWG and ERG.

Electrical and Rheological Properties of Colloidal of Alumina Suspensions

  • Wang, Xu-Hong;Yoshihiro Hirata
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 2000.06a
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    • pp.215-232
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    • 2000
  • The Valence(Z) of positively and negatively charged alumina particles in the dilute suspensions was analyzed with the electrical conductivity of the suspensions. The mobility of negative particles was lower than that of positive particles at a similar Z value because of the stronger effect of chemical bonding over the hydrated particle surfaces. The apparent viscosity of acidic suspensions of 1-40 vol % solid was lower than that of basic suspensions. This result was discussed based on the three important effects of the valence, concentration and nature of hydrated surface of alumina particles. The density of alumina compacts consolidated by filtration through gypsum molds became lower for the basic suspensions than for the acidic suspensions. This result was correlated to the properties of the colloidal alumina suspensions.

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Changes in the Physicochemical Properties of Ginseng by Roasting (볶음처리에 의한 인삼의 이화학적 특성변화)

  • Park, Myung-Han;Kim, Kyo-Chang;Kim, Jong-Seung
    • Journal of Ginseng Research
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    • v.17 no.3
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    • pp.228-231
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    • 1993
  • Physicochemival properties of ginseng roasted at 170 to $250^{\circ}C$ were investigated. Soluble solid contents in roast ginseng increased until $200^{\circ}C$, but decreased at higher temperature than $200^{\circ}C$. Contents of reducing sugar and protein were decreased and pH values were dropped, while optical density, acidic polysaccharide contents, precursor of brown pigments and hydrogen donating activities by DPPH were increased according to increasing in roast temperatures. The color distribution of roast ginseng expressed as Hunter L, a and b values demonstrated that lower L values and higher a values were observed according to higher temperature, but b values were almost not changed.

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Heavy Metal Adsorption of Anodically Treated Activated Carbon Fibers in Aqueous Solution

  • Park, Soo-Jin;Kim, Young-Mi
    • Carbon letters
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    • v.4 no.1
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    • pp.21-23
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    • 2003
  • In this work, the effect of anodic oxidation treatment on Cr(VI) ion adsorption behaviors of activated carbon fibers (ACFs) was investigated. The aqueous solutions of 10 wt% $H_3PO_4$ and $NH_4OH$ were used for acidic and basic electrolytes, respectively. Surface characteristics and textural properties of ACFs were determined by XPS and $N_2$ adsorption at 77 K. The heavy metal adsorption of ACFs was conducted by ICP. As a result, the adsorption amount of the anodized ACFs was improved in order of B-ACFs > A-ACFs > pristine-ACFs. In case of the anodized treated ACFs, the specific surface area was decreased due to the pore blocking or pore destroying by acidic electrolyte. However, the anodic oxidation led to an increase of the Cr(VI) adsorption, which can be attributed to an increase of oxygen-containing functional groups, such as, carboxylic, lactonic, and phenolic groups. It was clearly found that the Cr(VI) adsorption was largely influenced by the surface functional groups, in spite of the reduced specific surface area of the ACFs.

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Acid-Base and Spectroscopic Properties of 1,4-Benzodiazepines in Sodium Dodecyl Sulfate Micellar Solutions

  • Joon Woo Park;Hye Sung Cho
    • Bulletin of the Korean Chemical Society
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    • v.11 no.1
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    • pp.54-58
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    • 1990
  • Acid-base equilibria and spectroscopic properties of diazepam and chlorodiazepoxide were investigated in sodium dodecyl sulfate (SDS) micellar solutions as functions of pH. The results were compared with the behaviors in homogeneous aqueous media. The presence of SDS increased the $pK_a$ of chlorodiazepoxide to 6.3 from 4.7, while it has little effect on the $pK_a$ of diazepam. The acidic protonated form of diazepam was moderately fluorescent when the solution was excited at 350 nm, and emissnion intensity of the species was enhanced about 5 fold by the presence of SDS. On the other hand, the acidic solution of chlorodiazepoxide was non-fluorescent, but the neutral solution of the compound was fluorescent upon excitation at 350 nm. The emission peak of the neutral chlorodiazepoxide shifted to shorter wavelength region without significant change in the emission intensity upon the addition of SDS. Procedures for assay of the individual drugs from their mixture by the use of SDS micelle were discussed.

Variation of Rock Properties in Acidic Solution and Loading Condition (산성수 침수 및 하중 조건에서의 암석물성변화 연구)

  • Chung, Jae Hong;Park, Seung Hun;Lee, Seung Jun;Yu, Seungwon;Lee, Woo Hee;Kwon, Sangki
    • Tunnel and Underground Space
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    • v.26 no.3
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    • pp.154-165
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    • 2016
  • This paper presents experimental results to investigate the affects of acidic solution under loading condition on rock properties. In the experiment, the variations of various rock properties including effective porosity, thermal conductivity, and etc were investigated with different pHs of solution and magnitudes of loading. The results show that the rock property change was increased with low pH under loading. It was predicted that chemical reaction rate would be increased in low pH. Below the crack initiation stress of the rock specimen, the variation of rock property change was reduced with increased loading. It could be explained with the reduced chemical reaction area by the compressional loading if there is no crack generation.

Material and rheological properties of (glycidoxypropyl) trimethoxysilane modified colloidal silica coatings

  • Kang Hyun Uk;Park Jung Kook;Kim Sung Hyun
    • Korea-Australia Rheology Journal
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    • v.16 no.4
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    • pp.175-182
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    • 2004
  • Colloidal coating solution was prepared to enhance the hydrophilic property of the film surface. Water and ethanol were used as the dispersion media and (glycidoxypropyl) trimethoxysilane (GPS) as a binder in the colloidal silica coatings. Ethylene diamine was added to the colloidal silica solution as the curing agent. The colloidal silica solution was regarded as a hard-sphere suspension model with low volume fraction of the silica particles. Rheological properties of the silica suspensions modified with GPS have been investigated as a function of pH and concentration. The acidic solution showed high viscosity change by fast hydrolysis reaction and adsorption of the organic binders on the surface of silica particles. However, the hydrolysis was slow at the basic condition and the binders combined with themselves by condensation. The viscosity change was smallest at pH 7. The viscosity increased with the curing time after adding ethylenediamine, and the increase of viscosity at low pH was higher than that at high pH. The hydrophilic properties of the coating film were investigated by the contact angle of water and film surface. The smallest contact angle was shown under the strong acidic condition of pH 2.

The Soil Properties and Microbial Numbers of soil Samples Collected from Polluted and Unpolluted Areas in Korea (오염지역과 비오염지역의 토양의 특성과 토양 미생물의 분포)

  • 심재욱;이민순;이상선;이태수;이민웅
    • Journal of Korea Soil Environment Society
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    • v.3 no.2
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    • pp.31-39
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    • 1998
  • A total of 112 soil samples collected from polluted and unpolluted areas in Korea were investigated for physical properities (such as soil moisture, organic matter and soil pH) and biological properties (such as microbial numbers). The results of organic matter and soil pH showed a great variation(p=0.01) in the four areas, whereas soil moisture and organic matter were similar among three plant vegetations. There was a significant relationship(p=0.01 or 0.05) between soil pH and microbial number These results imply some variations in soil environment and may lead to unfavorable changes of plant vegetation in soil. Presumably, the above results appear to be resulted from soil acidification caused by an acidic rain.

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