• 제목/요약/키워드: pH agent

검색결과 1,345건 처리시간 0.03초

Bioactive characteristics of an implant surface coated with a pH buffering agent: an in vitro study

  • Pae, Hyung-Chul;Kim, Su-Kyoung;Park, Jin-Young;Song, Young Woo;Cha, Jae-Kook;Paik, Jeong-Won;Choi, Seong-Ho
    • Journal of Periodontal and Implant Science
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    • 제49권6호
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    • pp.366-381
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    • 2019
  • Purpose: The purpose of this study was to evaluate the effectiveness of conventional sandblasted, large-grit, acid-etched (SLA) surface coated with a pH buffering solution based on surface wettability, blood protein adhesion, osteoblast affinity, and platelet adhesion and activation. Methods: Titanium discs and implants with conventional SLA surface (SA), SLA surface in an aqueous calcium chloride solution (CA), and SLA surface with a pH buffering agent (SOI) were prepared. The wetting velocity was measured by the number of threads wetted by blood over an interval of time. Serum albumin adsorption was tested using the bicinchoninic acid assay and by measuring fluorescence intensity. Osteoblast activity assays (osteoblast adhesion, proliferation, differentiation, mineralization, and migration) were also performed, and platelet adhesion and activation assays were conducted. Results: In both the wetting velocity test and the serum albumin adsorption assay, the SOI surface displayed a significantly higher wetting velocity than the SA surface (P=0.000 and P=0.000, respectively). In the osteoblast adhesion, proliferation, differentiation, and mineralization tests, the mean values for SOI were all higher than those for SA and CA. On the osteoblast migration, platelet adhesion, and activation tests, SOI also showed significantly higher values than SA (P=0.040, P=0.000, and P=0.000, respectively). Conclusions: SOI exhibited higher hydrophilicity and affinity for proteins, cells, and platelets than SA. Within the limits of this study, it may be concluded that coating an implant with a pH buffering agent can induce the attachment of platelets, proteins, and cells to the implant surface. Further studies should be conducted to directly compare SOI with other conventional surfaces with regard to its safety and effectiveness in clinical settings.

Deinking of ONP with Cellulolytic Enzymes and Synthetic Collecter in Alkaline pH

  • Yoon, Kyong-Dong;Eom, Tae-Jin
    • 한국펄프종이공학회:학술대회논문집
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    • 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
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    • pp.451-454
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    • 2006
  • This paper presents an overview of ONP deinking efficiency with cellulolytic enzymes and synthetic collector in alkaline pH. Deinking is a series of unit operations designed to detach ink from cellulose fibers and separate the dispersed ink from the pulp slurry. Deinking chemicals are process aids that enable expensive mill equipment used in these unit operations to operate more efficiently - often much more efficiently. We propose the blended deinking agent with cellulolutic enzymes and synthetic collector in deinking pulp of conventional alkaline method. The deinking efficiency of old news print in alkaline pH was enhanced with enzyme treatments. The brightness of deinked pulp was increased with less residual ink particles and yield of enzymatic deinked pulp was improved compared to the deinked pulp of conventional alkaline method.

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디젤발전 자켓냉각시스템 열성능 향상 연구 (Performance Research of a Jacket Cooling Water System in a Diesel Electric Generation)

  • 이재근;문전수;윤석원;박필양
    • 한국수소및신에너지학회논문집
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    • 제20권6호
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    • pp.534-539
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    • 2009
  • One of the most efficient techniques improving the heat transfer performance of a diesel electric generation is a corrosion control in jacket cooling water system. The environmental parameters most affecting corrosion are dissolved salt concentration, temperature, and pH of cooling water. No corrosion occurs in carbon steel probe at pH 11 in normal operating condition of diesel electric generation cooling water. pH control agent in this study is trisodium phosphate. pH control appears to be the most convenient way to enhance the thermal performance of a diesel electric generation.

BaTiO3 습식직접합성 반응기구에 관한 연구 (Reaction Mechanism on the Synthesis of BaTiO3 by Direct Wet Process)

  • 이경희;이병하;김대웅
    • 한국세라믹학회지
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    • 제26권3호
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    • pp.371-380
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    • 1989
  • The purpose of this experiment is to elucidate the reaction mechanism concerning to the formation of crystalline BaTiO3 synthesized by adding the pH control agent(KOH soln) in TiCl4 and BaCl2 solution (Wet direct synthetic method). In this expeirment, it is identified that the amorphous barium-titanate having Ba-O-Ti bonding is formed above pH5 due to the -OH- ion and Ti-gel is formed below pH5 due to the polymerization of metatitanic acid. The bonding of the amorphous Ba-O-Ti is identified by FT-IR spectrum and crystallization temperature is about 82$0^{\circ}C$. If the pH of the above system according to the -OH- ion concentration is above 13.8, the polymerized metatitanic acid will be depolymerized and produce [TiO3]2+ion and crystalline BaTiO3 is formed by reacting the produced [TiO3]-- ion with the active Ba++ ion.

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염화동 수용액으로부터 Cu 미립자의 합성 (Synthesis of Uniform Cu Particles from Copper Chloride Solution)

  • 윤지희;권현우;유연태;김병규;김광수
    • 한국재료학회지
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    • 제15권4호
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    • pp.263-270
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    • 2005
  • In order to prepare the uniform copper particles from copper chloride solution, the reduction behavior of copper particles from copper chloride and the effects of reduction agent and dispersing agent was investigated. In the case that 2.56 M of $C_6H_8O_6$ was used as a reduction agent, the highly dispersed Cu particles with sharp size distribution were generated from 0.96M of copper chloride solution, and the size of Cu particles was $6\~10\;{\mu}m$. To form $Cu(NH_3)_4Cl_2$ complex solution, $NH_4OH$ was added in the copper chloride solution before the reductive reaction of Cu ion. The generated Cu particles have a two kind of shape, spherical and rod-like. In the case that $N_2H_4{\cdot}H_2O$ was used as a reduction agent, the very fine spherical Cu particles with the size of $0.2\~0.5\;{\mu}m$ was obtained. Arabic gum as a dispersing agent was more effective than $Na_4P_2O_7{\cdot}10H_2O$.

Effects of Hot Boning and Soy Sauce on the Processing Properties of Semi-dried Beef Jerky

  • Han, Doo-Jeong;Lee, Eui-Soo;Lee, Si-Kyung;Kim, Cheon-Jei
    • 한국축산식품학회지
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    • 제31권4호
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    • pp.497-505
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    • 2011
  • The objective of this study was to examine the effect of hot-boning and soy sauce as a curing agent on the processing properties of beef jerky. Beef jerky was prepared under the following four treatment conditions; Beef jerky with cold-boned beef and salt solution, beef jerky with cold-boned beef and soy sauce solution, beef jerky with hot-boned beef and salt solution, and beef jerky with hot-boned beef and soy sauce solution. Cured meat and jerky containing hot-boned beef had a significantly higher pH, water holding capacity (WHC), moisture content, Myofibrillar fragmentation index (MFI), processing yields, tenderness, and sensorial scores than samples containing cold-boned beef (p<0.05). Regardless of the raw materials, the jerky containing soy sauce had a significantly lower pH, WHC, moisture content, salt content, TBA, CIE $L^*$ and $b^*-$ values, and significantly higher MFI, mechanical tenderness, and sensorial scores (p<0.05). Based on these findings, we concluded that the use of hot-boned meat and soy sauce was the most effective boning method and curing agent during beef jerky processing.

내열성 항곰팡이 항생물질의 생산 최적화 (Optimization of the Production of a Thermostable Antifungal Antibiotic)

  • 신영준;정명주;정영기
    • KSBB Journal
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    • 제15권6호
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    • pp.584-588
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    • 2000
  • The optimum conditions for the production of an antifungal antibiotic from Bacillus sp. YJ-63 were investigated. The oprimumized medium consisted of 1.5% soluble starch, 1% tryptone and 0.5% yeast extract, and temperature and initial medium pH for production were optimal at 35$^{\circ}C$ and pH 6.0, respectively. Production yield was significantly improved by shaking culture using 50 ml medium in 500 ml flasks. Under these conditions, the production of the antifungal antibiotic was growth-dependent, from 35hrs into cultivation to the stationary phase and endospore formation.

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Al 소지상에 무전해 Ni도금시 응력 변화 (The Change in Residual Stress of Electroless Nickel Deposits on Aluminum Substrate)

  • 권진수;최순돈
    • 한국표면공학회지
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    • 제29권2호
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    • pp.100-108
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    • 1996
  • The internal stress of acidic electroless nickel deposits on zincated aluminum was determined by spiral contractometer. Several plating conditions such as inhibitor and complexing agent concentrations and pH affecting the internal stress were studied. The resulting intrinsic stress contribution to the total stress was discussed in terms of phosphorous content of the deposit, solution pH, and surface morphology. However, the most important was found to be thermal stress for the total stress of Al substrate, because of high thermal expansion coefficient of the aluminum substrate.

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무전해 Ni 도금의 전기화학적 고찰 (Electrochemical aspects of electroless nickel-boron plating)

  • 김영기;이원해
    • 한국표면공학회지
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    • 제26권4호
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    • pp.175-182
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    • 1993
  • Electroless plating of nickel was studied electrochemically in the presence of complexing agents. Nickel sulfate solution with dimethylamine borance(DMAB) as the reducing agent was used. Effects of temperature pH, concentration and complexing agents-citric acid, EDTA, tartaric acid-were studied.Experimental meas-urements showed that the rate of electroless nickel deposition was closely related to electrochemical parame-ters such as temdperature, pH, concentration and the properties of complexing agets.

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