• Title/Summary/Keyword: Adsorbed

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Analysis of Characteristics of Coupled Phosphorus in the Sewage (하수 중 인의 결합 특성 분석)

  • Choi, Hee-Jeong;Lee, Seung-Mok
    • Journal of Korean Society on Water Environment
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    • v.23 no.1
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    • pp.97-102
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    • 2007
  • The present investigation deals to achieve an accurate determination of the phosphorous present in the wastewater samples using the membrane reactor. The study may enable to quantify the dissolved (DP) and adsorbed phosphorous (AP), also the adsorbed phosphorous categorically identified as inorganic coupled phosphorous (DRP) and organic coupled phosphorous (NRP). Moreover, the study has been conducted separately in anaerobic and aerobic chamber. The results obtained showed that dissolved phosphorous only can occur in anaerobic chamber with ca. 25%. The study conducted for adsorbed phosphorous showed that the DRP has the percent composition in anaerobic and aerobic chamber respectively 33% and 40% i.e., 7% more in aerobic chamber. The similar values obtained for NRP was found to be 42% and 60% i.e., 18% more in aerobic chamber. On the other hand while comparing the results for NRP and DRP, it has to be noted that NRP has 9% and 20% more percent composition than DRP respectively in anaerobic and aerobic chamber. Further, the adsorbed phase showed the species Al-P, Fe-P in the aerobic chamber with the quotient of 7.73 mg/g TS (total solid) whereas in the anaerobic chamber it showed the species Fe-P and $Fe(OH)_3$-P with the 7.16 mg/g TS.

Revisiting $H_2$ and CO Interactions with Pt(111) Surfaces

  • Kim, Je-Heon;Jo, Sam-K.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.08a
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    • pp.203-203
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    • 2011
  • The importance of stepped single-crystal surfaces as model catalysts has been well recognized [1]. We re-investigated the adsorption properties of $H_2$ and CO, most important species in platinum-based catalysts, on nearly defect-free and highly stepped surfaces of one and the same Pt(111) crystal. While both being symmetric and single-peaked from the nearly defect-free surface, temperature-programmed desorption (TPD) spectra from the highly stepped surface saturated at 90 K with H and CO were triply- and doubly-peaked, respectively. Once pre-adsorbed, CO preempted step and then terrace sites, inhibiting the dissociative $H_2$ adsorption completely. Pre-adsorbed H inhibited the CO adsorption on terrace sites only, leaving defect sites intact for CO adsorption even at the saturation H precoverage. On defect-free Pt(111), while pre-adsorbed CO inhibited the dissociative $H_2$ adsorption completely, pre-adsorbed H could not inhibit the CO adsorption completely. These intriguing, but interesting results are discussed in terms of energetics/kinetics and the role of surface step sites in the dissociative adsorption of $H_2$ on Pt(111) [2].

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Adsorption of Preservatives by Sucralfate, Neusilin and Hydrotalcite in Suspension (현탁액중 수크랄페이트, 노이시린, 히드로탈사이트에 의한 방부제의 흡착)

  • Lee, Kye-Jun;Park, Eun-Seok;Jung, Byung-Ki;Chi, Sang-Cheol
    • Journal of Pharmaceutical Investigation
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    • v.25 no.4
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    • pp.331-338
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    • 1995
  • In order to screen appropriate preservatives for the suspension containing sucralfate, neusilin and hydrotalcite, the patterns and mechanism of the adsorption and desorption of several preservatives on these antacids were studied. The employed preservatives were parabens(methyl, propyl, butyl), chlorhexidine diacetate and sorbic acid. While none of parabens were adsorbed on three antacids, chlorhexidine diacetate was strongly adsorbed on all the antacids employed, especially on hydrotalcite. Sorbic acid was not adsorbed on neusilin and hydrotalcite, however, 65% of sorbic acid was adsorbed on sucralfate. The adsorption of chlorhexidine diacetate on neusilin and hydrotalcite was partly physical and partly chemical, while its adsorption on sucralfate was almost chemical. Sorbic acid was completely deserted from sucralfate. In all cases, the adsorption isotherms were fitted well to both Freundlich equation and Langmuir equation. Based on these results, parabens and sorbic acid were the preservatives of choice for the suspension containing sucralfate, neusilin and hydrotalcite.

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Changes in Physical and Mechanical Properties of Freon-Adsorbed and Heat - Treated Leaf Tobacco (Freon Gas흡착 및 열처리에 의한 담배조직의 물리적, 역학적 특성변화연구)

  • Kim, Ki-Hwan;Yoo, Kwang-Kun;Joo, Young-Serg
    • Journal of the Korean Society of Tobacco Science
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    • v.6 no.1
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    • pp.39-49
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    • 1984
  • In the tobacco industry, it is important to study the change of mechanical property occurring the expansion process. The purpose of this study is to attain basic data for development of a tobacco expansion method. 1 . Freon gas was adsorbed to tobacco under various conditions of temperature, relative humidity and pressure, and then the amount of freon gas adsorbed was analyzed by GC. Freon adsorption rate of Burley 21 was more than that of By104 at the same condition and about 17 $\pm$ 1% moisture content produced better adsorption rate. 2. Freon adsorbed sample were heated to about $150^{circ}C\;to\;230^{\circ}C$ in a drying oven and recycle duct form about 2 to 30 seconds, and then the change of mechanical property were measured. Heated leaf was damaged when the tissue was pressed by the force of above $0.5x10^8dyn/cm^2$. The optimum condition of no damage of the sample was below the temperature of 15$0^{\circ}C$ and heating time of 10 seconds. It was more economically advantages to treated sample in a recycle duct than to be in a drying oven. By this process, the specific volume of the heated sample was increased from 80 to 110 percent in comparison to that of untreated sample.

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A First Principles Study of Mn on AlGaP2 Semiconductor Surface (AlGaP2 반도체내와 표면의 Mn에 대한 제일원리 해석)

  • Kang, Byung Sub
    • Journal of the Semiconductor & Display Technology
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    • v.20 no.1
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    • pp.12-17
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    • 2021
  • The electronic and magnetic properties for Mn-adsorbed on the chalcopyrite (CH) AlGaP2 semiconductor are investigated by using first-principles FPLMTO method. The clean CH-AlGaP2 without adsorbed Mn is a p-type semiconductor with a direct band-gap. The Mn-adsorbed CH-AlGaP2 exhibits the ferromagnetic state. It is more energetically stable than the other magnetic ones. The interstitial site on P-terminated surface is more energetically favorable one than the Al/Ga-terminated surface, or the other adsorbing sites. In the case of Mn-adsorbed Al/Ga-terminated surface, it is induced a strong coupling between Mn-3d and neighboring P-3p electrons. The holes of partially unoccupied minority Mn-3d state and majority (or minority) Al-3p or P-3p state are induced. Thus a high magnetic moment of Mn is sustained by holes-mediated double-exchange coupling. It is noticeable that the semiconducting and half-metallic characteristics of CH-AlGaP2:Mn thin film is disappeared.

Isolation of Histone-type Basic Proteins from Lemna paucicostata (좀개구리밥에서의 Histone 型 鹽基性 蛋白質의 單離)

  • Yoon, Joo-Ok;Shin, Hong-Dae
    • Journal of the Korean Chemical Society
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    • v.8 no.4
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    • pp.164-168
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    • 1964
  • We isolated histone-type basic proteins from lemna paucicostata for the first time. Basic proteins were extracted directly with dilute mineral acids from homogenized lemna paucicostata. Amino acid compositions of basic protein portions adsorbed on Amberlite CG-50(at pH 6. 0) were resembled to those of calf thymus histones. Especially, lysine content was the greatest of the other amino acids. By chromatographic studies, adsorbed portions of basic protein components on carboxymethyl cellulose column(at pH 4. 2) were shown to be homogeneous to calf thymus histones, however, the area under the individual curve was different, and furthermore, the containing of a non-adsorbed portion in the large extent was markedly different from calf thymus histones. And amino acid compositions of adsorbed portions represented the histone-type basic propertes, but non-adsorbed portions were considered as a different protein compared with the typical histone. When calf thymus histone and protein components separated from lemna paucicostata were heated($60^{\circ}C$) with a solution of $HgSO_4-H_2SO_4$, precipitates were not obtained.

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Graphene Oxide-based Direct Measurement of DNase I Activity with Single Stranded DNA

  • Gang, Jongback
    • Bulletin of the Korean Chemical Society
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    • v.35 no.9
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    • pp.2749-2752
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    • 2014
  • Recent studies have shown that single-stranded DNA adsorbed onto graphene oxide is protected from DNase I cleavage. However, double-stranded DNA bound to graphene oxide and could be digested by DNase I. To elucidate whether single-stranded DNA is protect from DNase I in the presence of graphene oxide, this study conducted DNase I digestion using single-stranded DNA and single-stranded DNA containing the duplex region in the presence of graphene oxide. Addition of DNase I resulted in restoration of the fluorescence emission that had been quenched when DNA was adsorbed to graphene oxide. It indicates that DNase I cleaved the adsorbed single-stranded DNA onto graphene oxide, which was sufficient for the detection of DNase I activity.

A study on the photodegradiation of 4-hydroxy-biphenylcarboxylic acid by $TiO_2$ ($TiO_2$에 의한 4-hydroxy-biphenylcarboxylic acid의 광분해 연구)

  • 유수창;이상희;임정훈;김동희;전형탁;김복희
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.12 no.2
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    • pp.110-114
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    • 2002
  • The relationship between the orientation of molecules adsorbed on $_TiO2$ and their photoproducts was examined by employing HBPCA (4-hydroxy-biphenylcarboxylic acid) as a model organic pollutant. For this purpose, the Photoproducts after irradiation with UV radiation at various pH were compared by utilizing UV and Raman spectroscopies. It was found from these studies that pH affected the photoproducts probably due to the different orientations of the adsorbed molecules, and that the orientation of the adsorbed molecules and their photoproducts were closely correlated.

A Study of Vision Biomembrane Assembly using Photoreactive Protein Adsorbed Polypyrrole Film

  • Lim, Jeong-Ok;Huh, Jeung-Soo
    • Journal of Sensor Science and Technology
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    • v.9 no.3
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    • pp.208-212
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    • 2000
  • A protein based vision biomembrane was fabricated by adsorbing bacteriorhodopsin into electrochemically polymerized polypyrrole film substrate mainly through strong electrostatic interaction. The immobilized bacteriorhodopsin on the polypyrrole film was demonstrated by SEM and SRET. The light signal transducing function from the bacteriorhodopsin which was adsorbed into Polypyrrole film was evaluated by electroretinogram(ERG). A wave form analysis of the electroretinogram indicated that the adsorbed bacteriorhodopsin retained its activity and light signal was obtained from the protein for at least one month.

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Characteristics of methane sorption in surface modified activated carbon (표면개질 된 활성탄의 메탄흡장 특성)

  • Yun, Seok-Min;Kim, Ju-Wan;Jo, Won-Jun;Kim, Young-Ho;Lee, Young-Seak
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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    • pp.73-76
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    • 2007
  • In this study, methane gas adsorption ability of activated carbon (AC) with surface functional group effect, adsorbed methane amount was evaluated after nitric acid and ureatreatment of AC surface. Specific surface area and pore distribution of AC were studied though nitrogen adsorption isotherm at 77 K. Micro pore volume was calculated through H-K method. Adsorbed methane amount was evaluated through volume method at room temperature by using auto adsorption apparatus. Adsorbed methane amount of AC was found to increase with to specific surface area increase.Correlation proposed between the methane adsorption amount and surface nature indicates that the surface nature plays an important role on the adsorption amount at a given temperature.

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