• 제목/요약/키워드: alkaline agent

검색결과 210건 처리시간 0.027초

The Characteristics of Municipal wastewater Sludge Dewatering Using Oyster Shell Powder (굴껍질을 이용한 하수슬러지의 탈수특성에 관한 기초연구)

  • 신남철;문종익;정유진;장혜정;성낙창
    • Journal of Environmental Health Sciences
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    • 제26권2호
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    • pp.30-33
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    • 2000
  • The objective of this study is to examine the subsitiution effect of the waste oyster shell powder as the conditioning agent in municipal wasterwater sludge dewatering process. Beacuse the oyster shells have a large amount(about 38% by weight) of alkaline minerals, such as calcium and magnesium, they are thought to have the potential as a good conditioning agent. In this study, the physico-chemical properties of powdered oyster shells (75${\mu}{\textrm}{m}$ or 200 mesh) and the dewatering characteristics of municipal waste water sludge using powdered oyster shells and CaCO3 are investigated. The conclusions are as follows, 1. Oyster shell could produce calcium ions up to 14ppm at pH-7.0, and this represents that oyster shell is a potential properties as a good conditioner. 2. 100ml of wastewater sludges, conditioned with pretreated oyster shell, are dewatered to the level of 25% solid concentration. 3. Wasterwater sludges, conditioned with oyster shell and CaCO3 are dewatered to the level of 32% solid concentration. And this shows that two-stage combined conditioning process is desirable than the one-stage conditioning process.

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Evaluation of the Flowability and Compressive Strength of Alkali-Activated Blast Slag Mortar (고로슬래그 알칼리 활성 모르타르의 유동성 및 압축강도 평가)

  • Ryu, Gum-Sung;Kang, Hyun-Jin;Koh, Kyung-Taek;Lee, Jang-Hwa;Kang, Su-Tae
    • Proceedings of the Korea Concrete Institute Conference
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    • 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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    • pp.613-616
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    • 2008
  • Many researches on alkali-activated concrete that does not need the presence of cement as a binder have been carried out recently. Instead, the source of material such as fly ash and blast slag, that are rich in Silicon(Si) and Aluminium(Al), are activated by alkaline liquids to produce the binder. Hence concrete with no cement is effect reduction of CO$_2$ gas. In this study, we investigated the influence of the workability and compressive strength of mortar on water reducing agent, alkaline activator and curing method in oder to develop cementless blast slag based alkali-activated mortar. In view of the results, we found out that the flowability of mortar was lowered as increasing to mole concentration of NaOH, but not large the loss of flowability to 9M NaOH, most of water reducing agent was not effect. The compressive strength was improved as increasing to mole concentration of NaOH, was the most effect in 9M NaOH. The curing temperature and curing conditions on compressive strength of blast slag based alkali-activated mortar didn't influence.

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Effect of Hydroxyl Ethyl Cellulose Concentration in Colloidal Silica Slurry on Surface Roughness for Poly-Si Chemical Mechanical Polishing

  • Hwang, Hee-Sub;Cui, Hao;Park, Jin-Hyung;Paik, Ungyu;Park, Jea-Gun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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    • pp.545-545
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    • 2008
  • Poly-Si is an essential material for floating gate in NAND Flash memory. To fabricate this material within region of floating gate, chemical mechanical polishing (CMP) is commonly used process for manufacturing NAND flash memory. We use colloidal silica abrasive with alkaline agent, polymeric additive and organic surfactant to obtain high Poly-Si to SiO2 film selectivity and reduce surface defect in Poly-Si CMP. We already studied about the effects of alkaline agent and polymeric additive. But the effect of organic surfactant in Poly-Si CMP is not clearly defined. So we will examine the function of organic surfactant in Poly-Si CMP with concentration separation test. We expect that surface roughness will be improved with the addition of organic surfactant as the case of wafering CMP. Poly-Si wafer are deposited by low pressure chemical vapor deposition (LPCVD) and oxide film are prepared by the method of plasma-enhanced tetra ethyl ortho silicate (PETEOS). The polishing test will be performed by a Strasbaugh 6EC polisher with an IC1000/Suba IV stacked pad and the pad will be conditioned by ex situ diamond disk. And the thickness difference of wafer between before and after polishing test will be measured by Ellipsometer and Nanospec. The roughness of Poly-Si film will be analyzed by atomic force microscope.

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Wheat phytase can alleviate the cellular toxic and inflammatory effects of lipopolysaccharide

  • An, Jeongmin;Cho, Jaiesoon
    • Journal of Animal Science and Technology
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    • 제63권1호
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    • pp.114-124
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    • 2021
  • The objective of this study was to characterize the enzymatic hydrolysis of lipopolysaccharide (LPS) by wheat phytase and to investigate the effects of wheat phytase-treated LPS on in vitro toxicity, cell viability and release of a pro-inflammatory cytokine, interleukin (IL)-8 by target cells compared with the intact LPS. The phosphatase activity of wheat phytase towards LPS was investigated in the presence or absence of inhibitors such as L-phenylalanine and L-homoarginine. In vitro toxicity of LPS hydrolyzed with wheat phytase in comparison to intact LPS was assessed. Cell viability in human aortic endothelial (HAE) cells exposed to LPS treated with wheat phytase in comparison to intact LPS was measured. The release of IL-8 in human intestinal epithelial cell line, HT-29 cells applied to LPS treated with wheat phytase in comparison to intact LPS was assayed. Wheat phytase hydrolyzed LPS, resulting in a significant release of inorganic phosphate for 1 h (p < 0.05). Furthermore, the degradation of LPS by wheat phytase was nearly unaffected by the addition of L-phenylalanine, the inhibitor of tissue-specific alkaline phosphatase or L-homoarginine, the inhibitor of tissue-non-specific alkaline phosphatase. Wheat phytase effectively reduced the in vitro toxicity of LPS, resulting in a retention of 63% and 54% of its initial toxicity after 1-3 h of the enzyme reaction, respectively (p < 0.05). Intact LPS decreased the cell viability of HAE cells. However, LPS dephosphorylated by wheat phytase counteracted the inhibitory effect on cell viability. LPS treated with wheat phytase decreased IL-8 secretion from intestinal epithelial cell line, HT-29 cell to 14% (p < 0.05) when compared with intact LPS. In conclusion, wheat phytase is a potential therapeutic candidate and prophylactic agent for control of infections induced by pathogenic Gram-negative bacteria and associated LPS-mediated inflammatory diseases in animal husbandry.

The Effect of pH-adjusted Gold Colloids on the Formation of Gold Clusters over APTMS-coated Silica Cores

  • Park, Sang-Eun;Park, Min-Yim;Han, Po-Keun;Lee, Sang-Wha
    • Bulletin of the Korean Chemical Society
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    • 제27권9호
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    • pp.1341-1345
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    • 2006
  • An electrostatic interaction is responsible for the attachment of gold seeds of 1-3 nm onto APTMS (3-aminopropyl trimethoxysilane)-coated silica cores in the formation of gold clusters. A surface plasmon resonance and morphology of gold clusters were significantly affected by the pH of gold colloids prepared by THPC reducing agent. Gold colloids of alkaline pH induced the heterogeneous deposition of gold seeds onto the silica nanoparticles, probably due to the continuous reduction of residual gold ions during the attachment process. Gold colloids of acidic pH induced the monodisperse deposition of gold seeds, consequently leading to the formation of smooth gold layer on the silica nanoparticles surface. The gold nanoshells (core radius = 80 nm) prepared by gold colloids of pH 3.1 exhibited the more red-shift and relatively stronger intensity of plasmon absorption bands, compared with gold nanoshells prepared by alkaline gold colloids of pH 9.7.

The Formation Behavior of Non-metallic Inclusion in the Ba-added Hyper Duplex STS (Hyper Duplex STS 중 Ba 첨가 시 비금속개재물 생성거동)

  • Joo, S.W.;Hong, S.H.;Park, Y.M.;Kim, K.T.;Kim, J.S.;You, B.D.
    • Transactions of Materials Processing
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    • 제20권7호
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    • pp.504-511
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    • 2011
  • The alkaline earth metal Ba has a relatively low melting point. Because of its significantly high affinity to oxygen, nitrogen and sulfur, it is highly functional as a steel refining agent. But Ba can adversely affect the properties of steel especially the workability, because it can form a variety of inclusions. So, understanding of these inclusions is needed for improvement of the properties of steel. Thus a fundamental study in the formation behavior of non-metallic inclusions in Ba added Hyper Duplex STS melts was investigated. The amount of Ba, holding time and temperature were considered as experimental variables. The number of non-metallic inclusions decreased and the large particle size of non-metallic inclusions increased as the amount of Ba increased. The number of non-metallic inclusions also decreased and the large particle size increased with increased holding times and temperatures of molten steel.

Investigation into the Ecological and Natural Dyeing with Medicinal Plants after Fermentation by NURUK and the Effect of Natural Additives

  • Park, Youngmi
    • Textile Coloration and Finishing
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    • 제24권4호
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    • pp.260-269
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    • 2012
  • The aim of this study was to develop higher-value added dyeing materials with the fermentation-dyeing -mordanting system using only the natural ingredients by integrating traditional fermentation techniques with traditional dyeing technique. Nuruk, which is used mainly to ferment traditional foods, was used as a fermenting agent to ferment 5 different types of materials. Acidic burnt alum and alkaline calcium hydroxide were used as natural mordants. The dyeability checked after fermentation showed that both cotton and silk mordanted with Gardenia jasminoides did not show notable changes, and 10 days of fermentation was found to be appropriate. Sophora japonica L. performed better on cotton materials mordanted with slaked lime, and alkaline mordants were found to be more effective than acidic ones. With Rheum coreanum, a fermentation period of more than 24 days ($5^{th}$ fermentation) worked best on cotton material, showing a 5 fold increase in the K/S value after the $5^{th}$ slaked lime fermentation than with no fermentation. Rhus javanica L. was found to increase the color fastness to gentle washing and the fastness to light was found to possess 4 means that natural dyed fabric have the highest level of durability, the grade 1 the lowest level of fastness.

The Effect of Cyclosporin A on Osteoblast in vitro (Cyclosporin A가 in vitro에서 조골세포에 미치는 영향)

  • Kim, Jae-Woo;Lee, Hyun-Jung;Kang, Jung-Hwa;Ohk, Seung-Ho;Choi, Bong-Kyu;Yoo, Yun-Jung;Cho, Kyoo-Sung;Choi, Seong-Ho
    • Journal of Periodontal and Implant Science
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    • 제30권4호
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    • pp.747-757
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    • 2000
  • Cyclosporin A(CsA) is an immunosuppressive agent widely used for preventing graft rejecting response in organ transplantation. The basic properties of CsA to osteoblast has not been well known yet. A better understanding of the mechanisms of CsA function on bone could provide valuable information regarding basic properties of bone remodeling, pharmacotherapeutic intervention in metabolic bone disease, and the consequences of immunosuppression in bone physiology. The purpose of this study was to investigate the effect of CsA on osteoblast by evaluating parameters of proliferation, collagen synthetic activity, alkaline phosphatase activity, and ALP mRNA expression in mouse calvarial cell. 1. CsA ($3{\mu}g/m{\ell}$) treated mouse calvarial cell showed statistically significant increase in cell proliferation.(P<0.05) 2. CsA($1,\; 3{\mu}g/m{\ell}$) treated MC3T3 cell line showed statistically significant increase in cell proliferation. 3. The amount of collagen of CsA($3{\mu}g/m{\ell}$) treated mouse calvarial cell was decreased statistically significantly. 4. Alkaline phosphatase activity was increased statistically significantly in CsA treated group($1{\mu}g/m{\ell}$). 5. mRNA expression of ALP was increased in CsA treated group These results suggest that CsA could affect bone remodeling by modulating proliferation & differentiation of osteoblast.

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Synthesis of Functional Complex Material from Spent Alkaline Manganese Battery (폐(廢)알칼리망간전지(電池)로부터 기능성(機能性) 복합소재(複合素材) 제조(製造))

  • Kim, Tae-Hyun;Lee, Seoung-Won;Sohn, Jeong-Soo;Kang, Jin-Gu;Shin, Shun-Myung
    • Resources Recycling
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    • 제17권1호
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    • pp.66-72
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    • 2008
  • Fundamental studies for the synthesis of Mn-Zn ferrite powder were investigated using a series of leaching and coprecipitation processes from spent alkaline manganese batteries. Zinc and Manganese dissolution rates obtained at the reaction conditions of 100g/L pulp density, 3.0M $H_2SO_4$, $60^{\circ}C$ and 200 rpm with 30 ml $H_2O_2$ as a reducing agent were more than 97.9% and 93.9% and coprecipitation of Mn-Zn ferrite powder was performed according to various reaction conditions such as temperature, time and amount of $O_2$ gas injection using the leaching solution. As a result of coprecipitation, Mn-Zn ferrite could be synthesized directly at low temperature in the reaction condition pH 12, $80^{\circ}C$, $O_2$ 1.3 L/min. and 400 rpm. The synthesized Mn-Zn ferrite powder was spherical powder of $0.143{\mu}m$ particle size and had a saturation magnetization about 80 emu/g.

Eleutherococcus sessiliflorus induces differentiation of prechondrogenic ATDC5 Cells (오가피(Eleutherococcus sessiliflorus)의 전연골성 ATDC5 세포의 분화 유도)

  • Shrestha, Saroj Kumar;Song, Jungbin;Lee, Sung Hyun;Lee, Donghun;Kim, Hocheol;Soh, Yunjo
    • The Korea Journal of Herbology
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    • 제37권1호
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    • pp.51-59
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    • 2022
  • Objectives : The process through which mesenchymal cells condense and differentiate into chondrocytes to form new bone is known as endochondral bone formation. Chondrogenic differentiation and hypertrophy are essential steps in bone formation and are influenced by various factors. The stem bark and root bark of Eleutherococcus sessiliflorus (ES) have been widely used to treat growth retardation and arthritis in traditional Korean Medicine. In this study, we aimed to investigate the possible role of the stem bark of ES in the stimulation of chondrogenic differentiation in clonal murine chondrogenic ATDC5 cells. Methods : In ATDC5 cells treated with ES extract, cell viability and extracellular matrix production were determined using CCK-8 assay and Alcian blue staining, respectively, and alkaline phosphatase activity was measured. We also examined mRNA and protein expression levels of genes related to chondrogenic expression in ATDC5 cells using reverse transcription-polymerase chain reaction and western blot analyses. Results : ES extract increased the accumulation of Alcian blue-stained cartilage nodules and alkaline phosphatase activity in ATDC5 cells. It increased the mRNA expressions of chondrogenic markers including bone sialoprotein (BSP), cartilage collagens, Runt-related transcription factor-2 (RUNX-2), osteocalcin (OCN), β-catenin, and bone morphogenetic protein-2 (BMP-2), as well as the protein expressions of β-catenin, RUNX-2, BMP-2, and alkaline phosphatase (ALP). Conclusion : Taken together, these results suggest that ES extract exhibits a chondromodulating activity and therefore may be a possible agent for the treatment of bone growth disorders.