• Title/Summary/Keyword: Inorganic scale

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Evaluation of calcium carbonate scale formation on system design of seawater reverse osmosis plants (해수담수화 시설의 시스템 구성에 따른 $CaCO_3$ 스케일 형성능 진단)

  • Kang, Nam-Wook;Choi, Yang-Hun;Lee, Hye-Ju;Lee, Seock-Heon;Kweon, Ji-Hyang
    • Journal of Korean Society of Water and Wastewater
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    • v.24 no.2
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    • pp.143-155
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    • 2010
  • Fouling by inorganic scales needs to be prevented to effectively operate sea water reverse osmosis(SWRO) membrane systems. The extents of inorganic scaling with different array designs including one-pass, two-pass and several hybrid designs were evaluated using seawater from southern sea near the city of Chang-Won. The used methods for evaluation were Stiff and Davis Index(S&DSI) calculation and several laboratory experiments. The formation potential of inorganic scale fouling was quite great under the examined conditions, which was confirmed by the laboratory experimental results. The inorganic scale was not avoidable fouling if any anti-scaling measures were not applied. The RO showed decreased flux under the scale formation conditions. The increases in S&DSI from 1.43 to 5 made small decreases in flux, which indicated that formation of inorganic scales had more substantial effects on RO flux than amount of inorganic scales.

Effects of Antiscalant on Inorganic Fouling in Seawater Reverse Osmosis Membrane Processes (해수담수화 역삼투막 공정의 무기질오염에 대한 스케일 억제제 효과 연구)

  • Kang, Nam-Wook;Lee, Seock-Heon;Kweon, Ji-Hyang
    • Journal of Korean Society of Environmental Engineers
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    • v.33 no.9
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    • pp.677-685
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    • 2011
  • The reverse osmosis membrane processes have several operational problems. Fouling by inorganic scale occurs on membrane surface due to increases in concentrations over solubility by retaining ions on feed side of the membrane. Inorganic scales could be controlled by antiscalants or acid addition. In this study, three antiscalants having different characteristics were selected and evaluated on efficiency of $CaCO_3$ scale control. The $CaCO_3$ scale was inhibited by the antiscalants : 0.4 mg/L for SHMP, 0.6 mg/L for Spectra Guard, and 3 mg/L for Flocon 150 N. Increasing concentration factors of simulated sea water resulted in increases in antiscalant doses for the scale control. The increases in doses were positively proportional to the concentrate factors used in this study. Spectra Guard, one of the polyacrylate type antiscalants, was the most effective to control $CaCO_3$ scale. The antiscalants with the different scale inhibition time and doses implied the different control mechanisms.

Organic-Inorganic Hybrid Nanoflowers as Potent Materials for Biosensing and Biocatalytic Applications

  • Tran, Tai Duc;Kim, Moon Il
    • BioChip Journal
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    • v.12 no.4
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    • pp.268-279
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    • 2018
  • Flower-shaped organic-inorganic hybrid nanostructures, termed nanoflowers, have received considerable recent attention as they possess greatly enhanced activity, stability, durability, and even selectivity of entrapped organic biomolecules, which are much better than those from the conventional methods. They can be synthesized simply via co-incubation of organic and inorganic components in aqueous buffer at room temperature and yield hierarchical nanostructures with large surface-to-volume ratios, allowing for low-cost production by easy scale-up, as well as the high loading capacity of biomolecules without severe mass transfer limitations. Since a pioneering study reported on hybrid nanoflowers prepared with protein and copper sulfate, many other organic and inorganic components, which endow nanoflowers with diverse functionalities, have been employed. Thanks to these features, they have been applied in a diverse range of areas, including biosensors and biocatalysis. To highlight the progress of research on organic-inorganic hybrid nanoflowers, this review discusses their synthetic methods and mechanisms, structural and biological characteristics, as well as recent representative applications. Current challenges and future directions toward the design and development of multi-functional nanoflowers for their widespread utilization in biotechnology are also discussed.

Microstructural Investigations of $Al_2O_3$ Scale Formed on FeCrAl Steel during High Temperature Oxidation in $SO_2$

  • Homa, M.;Zurek, Z.;Morgiel, B.;Zieba, P.;Wojewoda, J.
    • Corrosion Science and Technology
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    • v.7 no.3
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    • pp.139-144
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    • 2008
  • The results of microstructure observations of the $Al_2O_3$ scale formed on a Fe-Cr-Al steel during high temperature oxidation in the $SO_2$ atmosphere are presented. Morphology of the scale has been studied by SEM and TEM techniques. Phase and chemical compositions have been studied by EDX and XRD techniques. The alumina oxide is a primary component of the scale. TEM observations showed that the scale was multilayer. The entire surface of the scale is covered with "whiskers", which look like very thin platelets and have random orientation. The cross section of a sample shows, that the "whiskers" are approximately $2{\mu}m$ high, however the compact scale layer on which they reside is $0.2{\mu}m$ thick. The scale layer was composed mainly of small equiaxial grains and a residual amount of small columnar grains. EDX analysis of the scale surface showed that the any sulfides were found in the formed outer and thin inner scale layer. A phase analysis of the scale formed revealed that it is composed mainly of the $\theta-Al_2O_3$ phase and a residual amount of $\alpha-Al_2O_3$.

Molecular-scale Structure of Pentacene at Functionalized Electronic Interfaces

  • Seo, Soon-Joo;Peng, Guowen;Mavrikakis, Manos;Ruther, Rose;Hamers, Robert J.;Evans, Paul G.;Kang, Hee-Jae
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.299-299
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    • 2011
  • A dipolar interlayer can cause dramatic changes in the device characteristics of organic field-effect transistors (OFETs) or photovoltaics. A shift in the threshold voltage, for example, has been observed in an OFET where the organic semiconductor active layer is deposited on SiO2 modified with a dipolar monolayer. Dipolar molecules can similarly be used to change the current-voltage characteristics of organic-inorganic heterojunctions. We have conducted a series of experiments in which different molecular linkages are placed between a pentacene thin film and a silicon substrate. Interface modifications with different linkages allow us to predict and examine the nature of tunneling through pentacene on modified Si surfaces with different dipole moment. The molecular-scale structure and the tunneling properties of pentacene thin films on modified Si (001) with nitrobenzene and styrene were examined using scanning tunneling spectroscopy. Electronic interfaces using organic surface dipoles can be used to control the band lineups of a semiconductor at organic/inorganic interfaces. Our results can provide insights into the charge transport characteristics of organic thin films at electronic interfaces.

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Aqeous Neutralizer as Reactive Solvents for Odorous Ammonia Removal

  • Park, Young-G.
    • Environmental Engineering Research
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    • v.13 no.3
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    • pp.119-124
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    • 2008
  • Ammonia is an inorganic compound that may cause severe odor problem. In this study the effectiveness of applying natural neutralizer to destroy and remove the odor-causing compound from gas streams was studied. Experimental result evaluated with a bench-scale apparatus via the neutralization of gas phase. This indicates that the natural neutralization depends on the gas concentration, gas residence time, temperature and pH. Removal efficiency of ammonia from gas stream was achieved by 95% using theconvection in the packed bed. This study proved the chemical neutralization technology was effective for controlling inorganic odor-causing compound.

Inorganic and Organic Nano Materials and Devices

  • Li, G.P.;Bachman, Mark
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2009.11a
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    • pp.4.1-4.1
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    • 2009
  • The dream of futurists andtechnologists is to build complex, multifunctional machines so small that theycan only be seen with the aid of a microscope. The unprecedented technologyadvancements in miniaturizing integrated circuits on semiconductors, and theresulting plethora of sophisticated, low cost electronic devices demonstratethe impact that micro/nano scale engineering can have when applied only to thearea of electrical and computer engineering. Emerging research efforts indeveloping organic and inorganic nano materials together with using micro/nanofabrication techniques for implementing integrated multifunctional devices hopeto yield similar revolutions in other engineering fields. By cross linking theindividual engineering fields through micro/nano technology, various organicand inorganic materials and miniaturized system devices can be developed thatwill have future impacts in the IT and life science applications. Yet to buildthe complex micromachines and nanomachine of the future, engineering will needto develop the technology capable of seamlessly integrating these materials andsubsystems together at the micro and nano scales. The micromachines of thefuture will be “integrated nanosystems,” complex devices requiring the integration of multiple materials,phenomena, technologies, and functions at the same platform. To develop thistechnology will require great efforts in materials science and engineering, infundamental and applied sciences. In this talk, we will first discuss thenature of micro and nanotechnology research for IT and life sciences, and thenintroduce selected current activities in micro and nanotechnology research fororganic and inorganic materials and devices. The newly developed micro/nanofabrication processes and devices, combined with in-depth scientificunderstandings of materials, can lead to rapid development of next generationsystems for applications in IT and life sciences.

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Study on the Fire Resistance of Light Weight Inorganic Polymer Concrete Panel Wall (Inorganic Polymer Concrete를 이용한 경량패널의 내화특성에 관한 실험적 연구)

  • Hwang, Ji-Soon;Kim, Woo-Jae;Kim, Dae-Hoi;Park, Dong-Cheol
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2011.11a
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    • pp.205-206
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    • 2011
  • Inorganic Polymer Concrete, a type of Alkali activated cement and concrete, is known for various excellent performances, especially for better performance in the area of high temperature heat resistance(thermal characteristic) than portland cement concrete.In this study, light weight concrete panel was manufactured using this Inorganic Polymer Concrete and then evaluated for fire resistance with a small-scale heating furnace. Since the result showed excellent fire resistance, it is considered usable for manufacturing fire resistant concrete panel wall.

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A Study on Organic/Inorganic Materials Deposition Using SAW-ED System (SAW-ED 시스템을 이용한 유/무기 소재 증착에 관한 연구)

  • Kim, Hyun Bum;Kim, Kyung Hwan;Ghayas, Siddiqi;Lim, Jong Hwan;Yang, Hyoung Chan;Choi, Kyung Hyun
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.15 no.5
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    • pp.100-108
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    • 2016
  • In various industries, many researches studies have been done in using nano thin film fabrication technology. In the field of printed electronics, various electronic devices can be fabricated using a direct printing process of on multiple functional materials. It has the advantages of low prices, environment-friendly environmentally friendly, flexibleility, large scale, mass production produced, simple process and so on. In this study, a viable thin film fabrication technology has beenwas introduced using the surface acoustic wave mechanism for thin film deposition. Fabrication of thin films using organic, inorganic and composite of organic/inorganic materials have been were analyzed through the experimental research. In this experiment, organic material MEH:PPV, inorganic material ZnO and composite material MEH:PPV/ZnO have been depo sited as thin films.

Applications and prospect of CDM project through recycling of inorganic waste (무기질(無機質) 폐기물(廢棄物)의 재활용(再活用)을 통한 CDM 사업(事業) 적용사례(適用事例) 및 전망(展望) - 시멘트 산업(産業)을 중심(中心)으로 -)

  • Cho, Jin-Sang;Cho, Kye-Hong;Ahn, Ji-Whan;Um, Seong-Il;Yeon, Kyu-Seok
    • Resources Recycling
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    • v.20 no.2
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    • pp.3-15
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    • 2011
  • Current, Registration fields of CDM projects are being conducted in a variety of parts such as mostly energy, chemical processing and manufacturing processes. However, there are not many CDM project registrations by recycling of inorganic waste. In this paper, analysis abroad CDM project and applications in order to review possibility of CDM project registration through the recycling of domestic inorganic waste were investigated. As a results, registered case of CDM project by inorganic waste recycling was researched to registrate in raw material alternative field of cement industry that inorganic waste can be used in large quantities. Application prospects of CDM project in Korea will be possible to analysis industrial scale, industry using inorganic raw materials, green house gas emissions and inorganic waste generated in large quantities.