• Title/Summary/Keyword: acidic water

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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.

Removal of BrO3- from aqueous solution (수용액에서 브롬산 이온을 제거하는 방법)

  • Lim, Heon-Sung;Kim, Chong-Hyeak;Lee, Sueg-Geun
    • Analytical Science and Technology
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    • v.24 no.5
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    • pp.401-405
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    • 2011
  • The efficient removal of bromate ($BrO_3^-$) from aqueous solutions was investigated using activated alumina. Bromate is a disinfection by-product, generally formed by the reaction of ozone and bromide in drinking water during ozonation process. The removal efficiency was about 90% for bromate (500 ng/mL) ion with acidic activated alumina but over 95% with silver or aluminum treated acidic activated alumina without any treatments of neutral water within 1~2 min.

A Study on the Adsorption Characteristic of Low Concentration Phenol by Activated Carbon (저농도(低濃度) 페놀의 활성탄(活性炭)에 대한 흡착특성(吸着特性)에 관(關)한 연구(硏究))

  • Kwon, Dae-Young;Park, Chung-Hyun
    • Journal of Korean Society of Water and Wastewater
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    • v.8 no.1
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    • pp.34-43
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    • 1994
  • It is well known that the adsorption character of activated carbon is dependent on the specific surface area and pore volume, but the relationship between the surface-chemical structure and the adsorption character has not been studied very often. The purpose of this study is to investigate the effect of the acidic surface functional groups of activated carbon and the adsorption characteristics of low concentration phenol. So three types of activated carbons and four different treatments were introduced to this isotherm experiment. These treatments were nontreatment, 1N $HNO_3$ treatment, 6N $HNO_3$ treatment, $H_2O_2$ treatment. The conclusions of this study are as followings. If the initial concentration of phenol is high as 5mg/l, the adsorption is dependent on the specific surface area. If the initial concentration of phenol is low as $100{\mu}g/l$, the adsorption is dependent on the average pore volume. The acidic surface functional groups prevent the adsorption of phenol molecules to activated carbon. And the adsorbed amount decreases more for $HNO_3$ treatment than for $H_2O_2$ treatment and more for concentrated $HNO_3$ treatment than for dilute $HNO_3$ treatment.

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Study of Euglenophytes Bloom and it's Impact on Fish Growth in Bangladesh

  • Rahman, M.M.;Jewel, M.A.S.;Khan, S.;Haque, M.M.
    • ALGAE
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    • v.22 no.3
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    • pp.185-192
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    • 2007
  • A study was carried out in nine fertilized fish ponds under three treatments (T-I, T-II and T-III) at Bangladesh Agricultural University, Mymensingh to see the bloom of euglenophytes with the intention of observing its impact on the growth of fish in culture condition. Some water quality parameters viz., temperature, dissolved oxygen, pH, PO4-P and NO3-N concentration and some biological parameters viz., phytoplankton population and growth of fish were monitored at fixed intervals. Euglenophytes showed a heavy bloom in late August in the ponds of T-II. The bloom was occurred by the genera, Euglena, Phacus and Trachelomonas of which Euglena was the most dominant genus. In relation of water quality parameters with euglenophytes bloom, it was hypothesized that euglenophytes prefers higher temperature and acidic environment with higher nutrient concentrations. Acidic environment and nutrient enrichment enhanced the bloom of euglenophytes which hampered the growth of other beneficial algal groups (chlorophytes and bacillariophytes) and fish. Due to heavy bloom, the fishes breathed with difficulty at the surface. The fishes in the heavy bloom ponds presented the weight values were lower than verified for those in the ponds where the bloom did not occur. Total production (calculated) of fish in different treatments ranged from 1355.89 to1760.63 kg ha–1 with significantly (p < 0.05) lowest in the ponds of T-II.

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.

Interannual Variations of Limnological and Ecological Characteristics in Acidic Lake Katanuma

  • Kikuchi, Eisuke;Takagi, Shigeto;Doi, Hideyuki;Shuichi, Shikano
    • Korean Journal of Ecology and Environment
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    • v.38 no.4 s.114
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    • pp.435-438
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    • 2005
  • We observed the physical, chemical, and biological characteristics of an acidic lake, Lake Katanuma, from 1998 to 2002 at weekly or biweekly intervals, except during the winter. This volcanic lake has a dimictic thermal pattern. In summer, the volcanic heat supply at the lake bottom results in weak thermal stratification. In 1998, 1999, and 2002, short-term holomixis was observed during the stratification period, when the anoxic, hydrogen sulfide-rich water from the hypolimnion spread across the entire lake. In contrast, distinct short-term holomixis did not occur during the stratificatlon period in 2000 and 2001. However, the early onset of the autumn turnover in August 2000 and 2001 caused anoxic conditions to persist throughout the entire water column for more than 2 weeks. The anoxic and hydrogen sulfide-rich conditions affected population densities of chironomid larvae (Chironomus acerbiphilus) and planktonic algae (Chlamydomonas acidophila), both dominant species in Lake Katanuma. Thus, the interannual variations of limnological characteristics influenced the seasonal population changes of these species.

Changes in Fiber Characteristics by Low Concentration Sodium Hydroxide Swelling and Beating (저농도 NaOH 팽윤과 고해에 따른 섬유특성 변화)

  • Kim, Ah-Ram;Choi, Kyoung-Hwa;Cho, Byoung-Uk
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.46 no.3
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    • pp.65-72
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    • 2014
  • In this study, effects of alkali swelling at low concentration below 2 percent on properties of hardwood bleached kraft pulp (HwBKP) were elucidated. Swelling treatment of HwBKP was performed at various NaOH concentrations with/without beating. Then, the swelling characteristics of pulp fiber was evaluated by measuring the solvent retention values such as water retention value (WRV) and isopropyl alcohol retention value (LRV). It was found that fiber characteristics were influenced by NaOH swelling even at low alkali concentration and beating treatment as well. The values of WRV and LRV were decreased when the alkali concentration was increased. It is the result from the decreased acidic groups of pulp which were formed during beating. The acidic groups could be neutralized and then removed by alkali. The difference between WRV and LRV was decreased with increasing alkali concentration while the difference was increased when the alkali swollen pulp was beaten. In addition, the crystalline structure of HwBKP was almost not changed while the crystallinity was influenced by swelling treatment at a low alkali concentration.

Morphological Behavior of Oxy-PAN Fiber upon pH Variation (Oxy-PAN 섬유의 산도 변화에 대한 형태학적 거동 특성)

  • 남재도;김재철;김현주;유동국;정창조
    • Polymer(Korea)
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    • v.26 no.4
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    • pp.492-500
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    • 2002
  • Oxidized-polyacrylonitrile (oxy-PAN) was prepared by oxidation of PAN fiber at $240^{\circ}C$, followed by base catalyzed hydrolysis reaction. The chemical structure of PAN fiber in various pH conditions was characterized by $^{13}C-NMR$ spectroscopy. The characteristic contraction and expansion behavior of oxy -PAN fiber was observed in acidic and basic medium, respectively. In basic condition, water molecules might be absorbed into the fiber with the movement of charge balancing $Na^+$ ion, on the other hand, the water molecules seemed to be expelled in acidic condition to result in contraction. It was also observed that the facile chemical modification occurred due to free diffusion of aqueous reagent into the hydrophilic PAN fiber, and the morphology was affected by pH condition.

Study of Hydrogen Evolution Reaction by Molybdenum Oxide Doped TiO2 Nanotubes (몰리브덴 산화물이 도핑된 티타늄 나노튜브전극의 수소 발생 반응 연구)

  • Oh, Kiseok;Yoo, Hyeonseok;Lee, Gibaek;Choi, Jinsub
    • Journal of the Korean institute of surface engineering
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    • v.49 no.6
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    • pp.521-529
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    • 2016
  • In this study, titanium nanotubes, prepared by anodization method, showing high surface and strong chemical stability in acidic and basic media, have been employed for the application to the electrodes for water splitting in KOH solution. Due to its high polarization resistance of $TiO_2$ itself, proper catalysts are essentially required to reduce overpotentials for water oxidation and reduction. Most of academic literature showed noble metal catalysts for foreign dopants in $TiO_2$ electrodes. From commercialization point of view, screening of low-cost catalyst is important. Herein, we propose molybdenum oxide as low-cost catalysts among various catalysts tested in the experiments, which exhibits the highest performance for hydrogen evolution reaction in highly alkaline solution. We showed that molybdenum oxide doped electrode can be operated in extreme acidic and basic conditions as well.

Scolopendra Pharmacopuncture Ameliorates Behavioral Despair in Mice Stressed by Chronic Restraint

  • Choi, Yu-Jin;Lee, Hwa-Young;Kim, Yunna;Cho, Seung-Hun
    • Journal of Pharmacopuncture
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    • v.20 no.4
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    • pp.257-264
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    • 2017
  • Introduction: Pharmacopuncture, which combines acupuncture with herbal medicine, is one of the newly developed acupuncture techniques that has recently been put into use. The possible mechanisms of scolopendra pharmacopuncture, as well as its potential effects on depressive symptoms, were investigated in this study by using a mouse model of chronic immobilization stress (CIS). Methods: C57BL/6 male mice were randomly assigned into three groups: mice not stressed with restraint and injected with distilled water, mice stressed with restraint and injected with distilled water, and mice stressed with restraint injected with scolopendra pharmacopuncture at a cervical site. Behavioral tests (an open field test, tail suspension test, and forced swimming test) were carried out after two weeks of CIS and injection treatments. The expression levels of glial fibrillary acidic protein (GFAP) in the hippocampus were determined by using western blot and immunohistochemistry analyses. Results: Mice exposed to CIS showed decreased behavioral activity, while scolopendra pharmacopuncture treatment significantly protected against the depressive-like behaviors induced by CIS. Moreover, scolopendra pharmacopuncture treatment increased GFAP protein levels in the hippocampi of the mice stressed by chronic immobilization. Conclusion: Scolopendra pharmacopuncture has an ameliorating effect on depressive behavior, which is partially mediated through protection against glial loss in the hippocampus.