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Sample records for ultrafiltration ceramic supports

  1. Hydrophilic Fe2O3 dynamic membrane mitigating fouling of support ceramic membrane in ultrafiltration of oil/water emulsion

    KAUST Repository

    Lu, Dongwei; Cheng, Wei; Zhang, Tao; Lu, Xinglin; Liu, Qianliang; Jiang, Jin; Ma, Jun

    2016-01-01

    Oil/water (O/W) emulsion is daily produced and difficult to be treated effectively. Ceramic membrane ultrafiltration is one of reliable processes for the treatment of O/W emulsion, yet still hindered by membrane fouling. In this study, two types of Fe2O3 dynamic membranes (i.e., pre-coated dynamic membrane and self-forming dynamic membrane) were prepared to mitigate the fouling of support ceramic membrane in O/W emulsion treatment. Pre-coated dynamic membrane (DM) significantly reduced the fouling of ceramic membrane (i.e., 10% increase of flux recovery rate), while self-forming dynamic membrane aggravated ceramic membrane fouling (i.e., 8.6% decrease of flux recovery rate) after four filtration cycles. A possible fouling mechanism was proposed to explain this phenomenon, which was then confirmed by optical images of fouled membranes and the analysis of COD rejection. In addition, the cleaning efficiency of composite membranes (i.e., Fe2O3 dynamic membrane and support ceramic membrane) was enhanced by substitution of alkalescent water backwash for deionized water backwash. The possible reason for this enhancement was also explained. Our result suggests that pre-coated Fe2O3 dynamic membrane with alkalescent water backwash can be a promising technology to reduce the fouling of ceramic membrane and enhance membrane cleaning efficiency in the treatment of oily wastewater.

  2. Hydrophilic Fe2O3 dynamic membrane mitigating fouling of support ceramic membrane in ultrafiltration of oil/water emulsion

    KAUST Repository

    Lu, Dongwei

    2016-03-17

    Oil/water (O/W) emulsion is daily produced and difficult to be treated effectively. Ceramic membrane ultrafiltration is one of reliable processes for the treatment of O/W emulsion, yet still hindered by membrane fouling. In this study, two types of Fe2O3 dynamic membranes (i.e., pre-coated dynamic membrane and self-forming dynamic membrane) were prepared to mitigate the fouling of support ceramic membrane in O/W emulsion treatment. Pre-coated dynamic membrane (DM) significantly reduced the fouling of ceramic membrane (i.e., 10% increase of flux recovery rate), while self-forming dynamic membrane aggravated ceramic membrane fouling (i.e., 8.6% decrease of flux recovery rate) after four filtration cycles. A possible fouling mechanism was proposed to explain this phenomenon, which was then confirmed by optical images of fouled membranes and the analysis of COD rejection. In addition, the cleaning efficiency of composite membranes (i.e., Fe2O3 dynamic membrane and support ceramic membrane) was enhanced by substitution of alkalescent water backwash for deionized water backwash. The possible reason for this enhancement was also explained. Our result suggests that pre-coated Fe2O3 dynamic membrane with alkalescent water backwash can be a promising technology to reduce the fouling of ceramic membrane and enhance membrane cleaning efficiency in the treatment of oily wastewater.

  3. Ceramic membrane fouling during ultrafiltration of oil/water emulsions: Roles played by stabilization surfactants of oil droplets

    KAUST Repository

    Lu, Dongwei

    2015-04-07

    Oil/water (O/W) emulsion stabilized by surfactants is the part of oily wastewater that is most difficult to handle. Ceramic membrane ultrafiltration presently is an ideal process to treat O/W emulsions. However, little is known about the fouling mechanism of the ceramic membrane during O/W emulsion treatment. This paper investigated how stabilization surfactants of O/W emulsions influence the irreversible fouling of ceramic membranes during ultrafiltration. An unexpected phenomenon observed was that irreversible fouling was much less when the charge of the stabilization surfactant of O/W emulsions is opposite to the membrane. The less ceramic membrane fouling in this case was proposed to be due to a synergetic steric effect and demulsification effect which prevented the penetration of oil droplets into membrane pores and led to less pore blockage. This proposed mechanism was supported by cross section images of fouled and virgin ceramic membranes taken with scanning electron microscopy, regression results of classical fouling models, and analysis of organic components rejected by the membrane. Furthermore, this mechanism was also verified by the existence of a steric effect and demulsification effect. Our finding suggests that ceramic membrane oppositely charged to the stabilization surfactant should be applied in ultrafiltration of O/W emulsions to alleviate irreversible membrane fouling. It could be a useful rule for ceramic membrane ultrafiltration of oily wastewater. © 2015 American Chemical Society.

  4. Ceramic membrane fouling during ultrafiltration of oil/water emulsions: roles played by stabilization surfactants of oil droplets.

    Science.gov (United States)

    Lu, Dongwei; Zhang, Tao; Ma, Jun

    2015-04-07

    Oil/water (O/W) emulsion stabilized by surfactants is the part of oily wastewater that is most difficult to handle. Ceramic membrane ultrafiltration presently is an ideal process to treat O/W emulsions. However, little is known about the fouling mechanism of the ceramic membrane during O/W emulsion treatment. This paper investigated how stabilization surfactants of O/W emulsions influence the irreversible fouling of ceramic membranes during ultrafiltration. An unexpected phenomenon observed was that irreversible fouling was much less when the charge of the stabilization surfactant of O/W emulsions is opposite to the membrane. The less ceramic membrane fouling in this case was proposed to be due to a synergetic steric effect and demulsification effect which prevented the penetration of oil droplets into membrane pores and led to less pore blockage. This proposed mechanism was supported by cross section images of fouled and virgin ceramic membranes taken with scanning electron microscopy, regression results of classical fouling models, and analysis of organic components rejected by the membrane. Furthermore, this mechanism was also verified by the existence of a steric effect and demulsification effect. Our finding suggests that ceramic membrane oppositely charged to the stabilization surfactant should be applied in ultrafiltration of O/W emulsions to alleviate irreversible membrane fouling. It could be a useful rule for ceramic membrane ultrafiltration of oily wastewater.

  5. EFFICIENCY OF ULTRAFILTRATION CERAMIC MEMBRANES FOR TOXIC ELEMENTS REMOVAL FROM WASTEWATERS

    Directory of Open Access Journals (Sweden)

    S. Alami Younssi

    2010-07-01

    Full Text Available The preparation and characterization of porous ceramics multilayer ultrafiltration membrane is described. The first step consisted to prepare high-quality macroporous support in Moroccan clay. The choice of this material is based on its natural abundance and thermal stability.The microporous interlayer was then prepared by slip casting from zirconia commercial powders and finally the active UF toplayers was obtained by sol-gel route using ZnAl2O4 and TiO2 mixed sols. The performance of ultrafiltration membrane (TiO2 (50�20– ZnAl2O4 (50� was evaluated by pores diameter, water flux, thickness and molecular weight cut off (MWCO. The water permeability measured for this composite membrane is 9.42 L/(m2•h•bar, the thickness is less than 700 nm, the pore diameter is centered near 5 nm and the MWCO was about 4500 Da.

  6. Recovery of biomolecules from marinated herring (Clupea harengus) brine using ultrafiltration through ceramic membranes

    DEFF Research Database (Denmark)

    Gringer, Nina; Hosseini, Seyed Vali; Svendsen, Tore

    2015-01-01

    Marinated herring processing brines, which are usually discarded, are rich in salt, protein, non-protein nitrogen, iron, fatty acids, antioxidant and even possess enzymatic activity. This study investigated the performance of ceramic ultrafiltration of two herring spice brines with a major focus...

  7. Differential natural organic matter fouling of ceramic versus polymeric ultrafiltration membranes.

    Science.gov (United States)

    Lee, Seung-Jin; Kim, Jae-Hong

    2014-01-01

    Ceramic ultrafiltration membranes has drawn increasing attention in drinking water treatment sectors as an alternative to traditional polymeric counterparts, yet only limited information has been made available about the characteristics of ceramic membrane fouling by natural organic matter. The effects of solution chemistry including ionic strength, divalent ion concentration and pH on the flux behavior were comparatively evaluated for ceramic and polymeric ultrafiltration of synthetic water containing model natural organic matter. Filtration characteristics were further probed via resistance-in-series model analysis, fouling visualization using quantum dots, batch adsorption test, contact angle measurement, solute-membrane surface adhesion force measurement, and quantitative comparison of fouling characteristics between ceramic and polymeric membranes. The results collectively suggested that the effects of solution chemistry on fouling behavior of ceramic membranes were generally similar to polymeric counterparts in terms of trends, while the extent varied significantly depending on water quality parameters. Lower fouling tendency and enhanced cleaning efficiency were observed with the ceramic membrane, further promoting the potential for ceramic membrane application to surface water treatment. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Ceramic Ultrafiltration of Marine Algal Solutions: A Comprehensive Study

    KAUST Repository

    Dramas, Laure

    2014-01-01

    understanding of UF membrane fouling caused by algal organic matter (AOM) is needed, in order to adjust the filtration conditions during algal bloom events. Polymeric MF/UF membranes are already widely used for RO pretreatment, but ceramic UF membranes can also

  9. Ceramic Ultrafiltration of Marine Algal Solutions: A Comprehensive Study

    KAUST Repository

    Dramas, Laure

    2014-09-01

    Algal bloom can significantly impact reverse osmosis desalination process and reduce the drinking water production. In 2008, a major bloom event forced several UAE reverse osmosis plants to stop their production, and in this context, a better understanding of UF membrane fouling caused by algal organic matter (AOM) is needed, in order to adjust the filtration conditions during algal bloom events. Polymeric MF/UF membranes are already widely used for RO pretreatment, but ceramic UF membranes can also be an alternative for the filtration of marine algal solutions. The fouling potential of the Red Sea and the Arabian Sea, sampled at different seasons, along with four algal monocultures grown in laboratory, and one mesocosm experiment in the Red Sea was investigated. Algal solutions induce a stronger and more irreversible fouling than terrestrial humic solution, toward ceramic membrane. During algal bloom events, this fouling is enhanced and becomes even more problematic at the decline phase of the bloom, for a similar initial DOC. Three main mechanisms are involved: the formation of a cake layer at the membrane surface; the penetration of the algal organic matter (AOM) in the pore network of the membrane; the strong adhesion of AOM with the membrane surface. The last mechanism is species-specific and metal-oxide specific. In order to understand the stronger ceramic UF fouling at the decline phase, AOM quality was analyzed every two days. During growth, AOM is getting enriched in High Molecular Weight (HMW) structures (> 200 kDa), which are mainly composed by proteins and polysaccharides, and these compounds seem to be responsible for the stronger fouling at decline phase. In order to prevent the fouling of ceramic membrane, coagulation-flocculation (CF) using ferric chloride was implemented prior to filtration. It permits a high removal of HMW compounds and greatly reduces the fouling potential of the algal solution. During brief algal bloom events, CF should be

  10. Pretreatment with ceramic membrane microfiltration in the clarification process of sugarcane juice by ultrafiltration

    Directory of Open Access Journals (Sweden)

    Priscilla dos Santos Gaschi

    2014-04-01

    Full Text Available In the present study, the sugar cane juice from COCAFE Mill, was clarified using tubular ceramic membranes (α-Al2O3/TiO2 with pore size of 0.1 and 0.3 µm, and membrane area of 0.005 m2. Experiments were performed in batch with sugar cane juice, in a pilot unit of micro and ultrafiltration using the principle of tangential filtration. The sugar cane juice was settled for one hour and the supernatant was treated by microfiltration. After that, the MF permeate was ultrafiltered. The experiments of micro and ultrafiltration were carried out at 65ºC and 1 bar. The ceramic membranes were able to remove the colloidal particles, producing a limpid permeated juice with color reduction. The clarification process with micro- followed by ultrafiltration produced a good result with an average purity rise of 2.74 units, 99.4% lower turbidity and 44.8% lighter color in the permeate.

  11. Ceramic membrane ultrafiltration of natural surface water with ultrasound enhanced backwashing.

    Science.gov (United States)

    Boley, A; Narasimhan, K; Kieninger, M; Müller, W-R

    2010-01-01

    Ultrafiltration membrane cleaning with ultrasound enhanced backwashing was investigated with two ceramic membrane systems in parallel. One of them was subjected to ultrasound during backwashing, the other acted as a reference system. The feed water was directly taken from a creek with a sedimentation process as only pre-treatment. The cleaning performance was improved with ultrasound but after 3 weeks of operation damages occurred on the membranes. These effects were studied with online measurements of flux, trans-membrane-pressure and temperature, but also with integrity tests, turbidity measurements and visual examination.

  12. Ceramic membrane by tape casting and sol-gel coating for microfiltration and ultrafiltration application

    Science.gov (United States)

    Das, Nandini; Maiti, H. S.

    2009-11-01

    Alumina membrane filters in the form of thin (0.3-0.8 mm) discs of 25-30 mm diameter suitable for microfiltration application have been fabricated by tape-casting technique. Further using this microfiltration membrane as substrate, boehmite sol coating was applied on it and ultrafiltration membrane with very small thickness was formed. The pore size of the microfiltration membrane could be varied in the range of 0.1-0.7 μm through optimisation of experimental parameter. In addition, each membrane shows a very narrow pore size distribution. The most important factor, which determines the pore size of the membrane, is the initial particle size and its distribution of the ceramic powder. The top thin ultrafiltration, boehmite layer was prepared by sol-gel method, with a thickness of 0.5 μm. Particle size of the sol was approximately 30-40 nm. The structure and formation of the layer was analysed through TEM. At 550 °C formation of the top layer was completed. The pore size of the ultrafiltration membrane measured from TEM micrograph was almost 10 nm. Results of microbial (Escherichia coli—smallest-sized water-borne bacteria) test confirm the possibility of separation through this membrane

  13. Cross flow ultrafiltration of Cr (VI) using MCM-41, MCM-48 and Faujasite (FAU) zeolite-ceramic composite membranes.

    Science.gov (United States)

    Basumatary, Ashim Kumar; Kumar, R Vinoth; Ghoshal, Aloke Kumar; Pugazhenthi, G

    2016-06-01

    This work describes the removal of Cr (VI) from aqueous solution in cross flow mode using MCM-41, MCM-48 and FAU zeolite membranes prepared on circular shaped porous ceramic support. Ceramic support was manufactured using locally available clay materials via a facile uni-axial compaction method followed by sintering process. A hydrothermal technique was employed for the deposition of zeolites on the ceramic support. The porosity of ceramic support (47%) is reduced by the formation of MCM-41 (23%), MCM-48 (22%) and FAU (33%) zeolite layers. The pore size of the MCM-41, MCM-48 and FAU membrane is found to be 0.173, 0.142, and 0.153 μm, respectively, which is lower than that of the support (1.0 μm). Cross flow ultrafiltration experiments of Cr (VI) were conducted at five different applied pressures (69-345 kPa) and three cross flow rates (1.11 × 10(-7) - 2.22 × 10(-7) m(3)/s). The filtration studies inferred that the performance of the fabricated zeolite composite membranes is optimum at the maximum applied pressure (345 kPa) and the highest rejection is obtained with the lowest cross flow rate (1.11 × 10(-7) m(3)/s) for all three zeolite membrane. The permeate flux of MCM-41, MCM-48 and FAU zeolite composite membranes are almost remained constant in the entire duration of the separation process. The highest removal of 82% is shown by FAU membrane, while MCM-41 and MCM-48 display 75% and 77% of Cr (VI) removal, respectively for the initial feed concentration of 1000 ppm with natural pH of the solution at an applied pressure of 345 kPa. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Ultrafiltration technology with a ceramic membrane for reactive dye removal: optimization of membrane performance.

    Science.gov (United States)

    Alventosa-deLara, E; Barredo-Damas, S; Alcaina-Miranda, M I; Iborra-Clar, M I

    2012-03-30

    An ultrafiltration (UF) ceramic membrane was used to decolorize Reactive Black 5 (RB5) solutions at different dye concentrations (50 and 500 mg/L). Transmembrane pressure (TMP) and cross-flow velocity (CFV) were modified to study their influence on initial and steady-state permeate flux (J(p)) and dye rejection (R). Generally, J(p) increased with higher TMP and CFV and lower feed concentration, up to a maximum steady-state J(p) of 266.81 L/(m(2)h), obtained at 3 bar, 3m/s and 50mg/L. However, there was a TMP value (which changed depending on operating CFV and concentration) beyond which slight or no further increase in steady-state J(p) was observed. Similarly, the higher the CFV was, the more slightly the steady-state J(p) increased. Furthermore, the effectiveness of ultrafiltration treatment was evaluated through dye rejection coefficient. The results showed significant dye removals, regardless of the tested conditions, with steady-state R higher than 79.8% for the 50mg/L runs and around 73.2% for the 500 mg/L runs. Finally response surface methodology (RSM) was used to optimize membrane performance. At 50mg/L, a TMP of 4 bar and a CFV of 2.53 m/s were found to be the conditions giving the highest steady-state J(p), 255.86 L/(m(2)h), and the highest R, 95.2% simultaneously. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Performance of ceramic ultrafiltration and reverse osmosis membranes in treating car wash wastewater for reuse.

    Science.gov (United States)

    Moazzem, Shamima; Wills, Jamie; Fan, Linhua; Roddick, Felicity; Jegatheesan, Veeriah

    2018-03-01

    Reusing treated effluents in industries is a great option to conserve freshwater resources. For example, car wash centres all over Australia are estimated to use 17.5 billion litres of water and discharge it as wastewater and spend $75 million a year for both purchasing fresh water and for treating and/or discharging the wastewater. Therefore, it is important to develop simple but reliable systems that can help to treat and reuse car wash wastewater. Significant savings could also be associated with the implementation of such systems. This study evaluates the performance of granular and membrane filtration systems with coagulation/flocculation and sedimentation in treating car wash wastewater for the purpose of reuse. Overall, 99.9% of turbidity, 100% of suspended solids and 96% of COD were removed from the car wash wastewater after treating by coagulation, flocculation, sedimentation, sand filtration, ceramic ultrafiltration and reverse osmosis and the treated water meets the standards required for class A recycled water in Australia and standards imposed in Belgium and China. The treated water can be reused. However, optimisation is required to reduce the sludge produced by this system.

  16. Study on an integrated process combining ozonation with ceramic ultra-filtration for decentralized supply of drinking water.

    Science.gov (United States)

    Zhu, Jia; Fan, Xiao J; Tao, Yi; Wei, De Q; Zhang, Xi H

    2014-09-19

    An integrated process was specifically developed for the decentralized supply of drinking water from micro-polluted surface water in the rural areas of China. The treatment process combined ozonation with ceramic ultra-filtration (UF), coagulation for pre-treatment and granular activated carbon filtration. A flat-sheet ceramic membrane was used with a cut-off of 60 nm and the measurement of 254 mm (length) × 240 mm (width) × 6 mm (thickness). Ozonation and ceramic UF was set up whthin one reactor. The experimental results showed that the removal efficiencies of the dissolved organic carbon (DOC) and the formation potential of trihalomethanes (THMs), haloacetic acids (HAAs) and ammonia were 80%, 76%, 70% and 90%, respectively; that the turbidity of the product water was below 0.2 NTU and the particle count number (particles larger than 2 μm) was less than 50 counts per mL. The result also showed that all the pathogenic microorganisms were retained by the ceramic and that UF. Ozonation played a critical role in the control of membrane fouling and the removal of contaminants. Exactly, the membrane fouling can be controlled in situ with 3 mg L(-1) ozone at the permeate flux of 80 L m(-2) h(-1), yet the required dosage of ozone was dependent on the quality of the raw water. Therefore, this study is able to provide a highly compacted system for decentralized supply of high-quality drinking water in terms of both chemical and microbiological safety for the rural areas in China.

  17. Separation Properties of Wastewater Containing O/W Emulsion Using Ceramic Microfiltration/Ultrafiltration (MF/UF Membranes

    Directory of Open Access Journals (Sweden)

    Kanji Matsumoto

    2013-06-01

    Full Text Available Washing systems using water soluble detergent are used in electrical and mechanical industries and the wastewater containing O/W emulsion are discharged from these systems. Membrane filtration has large potential for the efficient separation of O/W emulsion for reuses of treated water and detergent. The separation properties of O/W emulsions by cross-flow microfiltration and ultrafiltration were studied with ceramic MF and UF membranes. The effects of pore size; applied pressure; cross-flow velocity; and detergent concentration on rejection of O/W emulsion and flux were systematically studied. At the condition achieving complete separation of O/W emulsion the pressure-independent flux was observed and this flux behavior was explained by gel-polarization model. The O/W emulsion tended to permeate through the membrane at the conditions of larger pore size; higher emulsion concentration; and higher pressure. The O/W emulsion could permeate the membrane pore structure by destruction or deformation. These results imply the stability of O/W emulsion in the gel-layer formed on membrane surface play an important role in the separation properties. The O/W emulsion was concentrated by batch cross-flow concentration filtration and the flux decline during the concentration filtration was explained by the gel- polarization model.

  18. Separation Properties of Wastewater Containing O/W Emulsion Using Ceramic Microfiltration/Ultrafiltration (MF/UF) Membranes

    Science.gov (United States)

    Nakamura, Kazuho; Matsumoto, Kanji

    2013-01-01

    Washing systems using water soluble detergent are used in electrical and mechanical industries and the wastewater containing O/W emulsion are discharged from these systems. Membrane filtration has large potential for the efficient separation of O/W emulsion for reuses of treated water and detergent. The separation properties of O/W emulsions by cross-flow microfiltration and ultrafiltration were studied with ceramic MF and UF membranes. The effects of pore size; applied pressure; cross-flow velocity; and detergent concentration on rejection of O/W emulsion and flux were systematically studied. At the condition achieving complete separation of O/W emulsion the pressure-independent flux was observed and this flux behavior was explained by gel-polarization model. The O/W emulsion tended to permeate through the membrane at the conditions of larger pore size; higher emulsion concentration; and higher pressure. The O/W emulsion could permeate the membrane pore structure by destruction or deformation. These results imply the stability of O/W emulsion in the gel-layer formed on membrane surface play an important role in the separation properties. The O/W emulsion was concentrated by batch cross-flow concentration filtration and the flux decline during the concentration filtration was explained by the gel- polarization model. PMID:24958621

  19. Evaluation of Removal Mechanisms in a Graphene Oxide-Coated Ceramic Ultrafiltration Membrane for Retention of Natural Organic Matter, Pharmaceuticals, and Inorganic Salts.

    Science.gov (United States)

    Chu, Kyoung Hoon; Fathizadeh, Mahdi; Yu, Miao; Flora, Joseph R V; Jang, Am; Jang, Min; Park, Chang Min; Yoo, Sung Soo; Her, Namguk; Yoon, Yeomin

    2017-11-22

    Functionalized graphene oxide (GO), derived from pure graphite via the modified Hummer method, was used to modify commercially available ceramic ultrafiltration membranes using the vacuum method. The modified ceramic membrane functionalized with GO (ceramic GO ) was characterized using a variety of analysis techniques and exhibited higher hydrophilicity and increased negative charge compared with the pristine ceramic membrane. Although the pure water permeability of the ceramic GO membrane (14.4-58.6 L/m 2 h/bar) was slightly lower than that of the pristine membrane (25.1-62.7 L/m 2 h/bar), the removal efficiencies associated with hydrophobic attraction and charge effects were improved significantly after GO coating. Additionally, solute transport in the GO nanosheets of the ceramic GO membrane played a vital role in the retention of target compounds: natural organic matter (NOM; humic acid and tannic acid), pharmaceuticals (ibuprofen and sulfamethoxazole), and inorganic salts (NaCl, Na 2 SO 4 , CaCl 2 , and CaSO 4 ). While the retention efficiencies of NOM, pharmaceuticals, and inorganic salts in the pristine membrane were 74.6%, 15.3%, and 2.9%, respectively, these increased to 93.5%, 51.0%, and 31.4% for the ceramic GO membrane. Consequently, the improved removal mechanisms of the membrane modified with functionalized GO nanosheets can provide efficient retention for water treatment under suboptimal environmental conditions of pH and ionic strength.

  20. PERFORMANCE AND SELECTIVITY OF CERAMIC MEMBRANES IN THE ULTRAFILTRATION OF MODEL EMULSION IN SALINE

    Directory of Open Access Journals (Sweden)

    Konrad ĆWIRKO

    2017-04-01

    Full Text Available Oily wastewaters from different onshore and offshore installations and from maritime transport pose a serious threat to the environment so they must be treated by multistage separation also including membrane processes. The main advantages of such membranes are high performance and selectivity, high resistance for temperature and pressure, resistance for acids, bases and solvents, long service life and for application – significant reduction of industries and transport environmental impact. This work presents the results of the process of separation of oil from the emulsion with NaCl addition. Research was performed with a use of laboratory installation with ceramic 300 kDa membrane. The analysis concerned performance and selectivity of a membrane in the function of time and test results have been subsequently compared with the requirements of the IMO.

  1. Influence of surface properties of filtration-layer metal oxide on ceramic membrane fouling during ultrafiltration of oil/water emulsion

    KAUST Repository

    Lu, Dongwei

    2016-04-01

    In this work, ceramic ultrafiltration membranes deposited with different metal oxides (i.e., TiO2, Fe2O3, MnO2, CuO, and CeO2) of around 10 nm in thickness and similar roughness were tested for O/W emulsion treatment. Distinct membrane fouling tendency was observed, which closely correlated to the properties of the filtration-layer metal oxides (i.e. surface hydroxyl groups, hydrophilicity, surface charge, and adhesion energy for oil droplets). In consistent with the distinct bond strength of the surface hydroxyl groups, hydrophilicity of these common metal oxides are quite different. The differences in hydrophilicity consequently lead to different adhesion of these metal oxides towards oil droplets which consists very well with irreversible membrane fouling tendency. In addition, the surface charge of the metal oxide opposite to that of emulsion can help to alleviate irreversible membrane fouling in ultrafiltration. Highly hydrophilic Fe2O3 with lowest fouling tendency could be a potential filtration-layer material for the fabrication/modification of ceramic membranes for O/W emulsion treatment. To the best of our knowledge, this is the first study clearly showing the correlations between surface properties of filtration-layer metal oxides and ceramic membrane fouling tendency by O/W emulsion.

  2. Influence of Surface Properties of Filtration-Layer Metal Oxide on Ceramic Membrane Fouling during Ultrafiltration of Oil/Water Emulsion.

    Science.gov (United States)

    Lu, Dongwei; Zhang, Tao; Gutierrez, Leo; Ma, Jun; Croué, Jean-Philippe

    2016-05-03

    In this work, ceramic ultrafiltration membranes deposited with different metal oxides (i.e., TiO2, Fe2O3, MnO2, CuO, and CeO2) of around 10 nm in thickness and similar roughness were tested for O/W emulsion treatment. A distinct membrane fouling tendency was observed, which closely correlated to the properties of the filtration-layer metal oxides (i.e., surface hydroxyl groups, hydrophilicity, surface charge, and adhesion energy for oil droplets). Consistent with the distinct bond strength of the surface hydroxyl groups, hydrophilicity of these common metal oxides is quite different. The differences in hydrophilicity consequently lead to different adhesion of these metal oxides toward oil droplets, consistent with the irreversible membrane fouling tendency. In addition, the surface charge of the metal oxide opposite to that of emulsion can help to alleviate irreversible membrane fouling in ultrafiltration. Highly hydrophilic Fe2O3 with the lowest fouling tendency could be a potential filtration-layer material for the fabrication/modification of ceramic membranes for O/W emulsion treatment. To the best of our knowledge, this is the first study clearly showing the correlations between surface properties of filtration-layer metal oxides and ceramic membrane fouling tendency by O/W emulsion.

  3. Influence of surface properties of filtration-layer metal oxide on ceramic membrane fouling during ultrafiltration of oil/water emulsion

    KAUST Repository

    Lu, Dongwei; Zhang, Tao; Gutierrez, Leo; Ma, Jun; Croue, Jean-Philippe

    2016-01-01

    In this work, ceramic ultrafiltration membranes deposited with different metal oxides (i.e., TiO2, Fe2O3, MnO2, CuO, and CeO2) of around 10 nm in thickness and similar roughness were tested for O/W emulsion treatment. Distinct membrane fouling tendency was observed, which closely correlated to the properties of the filtration-layer metal oxides (i.e. surface hydroxyl groups, hydrophilicity, surface charge, and adhesion energy for oil droplets). In consistent with the distinct bond strength of the surface hydroxyl groups, hydrophilicity of these common metal oxides are quite different. The differences in hydrophilicity consequently lead to different adhesion of these metal oxides towards oil droplets which consists very well with irreversible membrane fouling tendency. In addition, the surface charge of the metal oxide opposite to that of emulsion can help to alleviate irreversible membrane fouling in ultrafiltration. Highly hydrophilic Fe2O3 with lowest fouling tendency could be a potential filtration-layer material for the fabrication/modification of ceramic membranes for O/W emulsion treatment. To the best of our knowledge, this is the first study clearly showing the correlations between surface properties of filtration-layer metal oxides and ceramic membrane fouling tendency by O/W emulsion.

  4. PROCESSING AND CHARACTERIZATION OF TUBULAR CERAMIC SUPPORT FOR MICROFILTRATION MEMBRANE PREPARED FROM PYROPHYLLITE CLAY

    Directory of Open Access Journals (Sweden)

    Abedallah Talidi

    2011-09-01

    Full Text Available Tubular macroporous support for ceramic microfiltration membranes were prepared by extrusion followed by sintering of the low cost pyrophyllite clay. Clay powders mixed with some organic additives can be extruded to form a porous tubular support. The average pore size of the membrane is observed to increase from 5 µm to 10.8 µm when sintering temperature increase from 900 °C to 1200 °C. However, with the increase in temperature from 900 °C to 1200 °C, the support porosity is reduced from 47% to 30% and flexural strength is increased from 4 MPa to 17 MPa. The fabricated macro-porous supports are expected to have potential applications in the pre-treatment and also can be used like support for membranes of ultra-filtration.

  5. Study and optimization of the ultrasound-enhanced cleaning of an ultrafiltration ceramic membrane through a combined experimental-statistical approach.

    Science.gov (United States)

    Alventosa-deLara, E; Barredo-Damas, S; Alcaina-Miranda, M I; Iborra-Clar, M I

    2014-05-01

    Membrane fouling is one of the main drawbacks of ultrafiltration technology during the treatment of dye-containing effluents. Therefore, the optimization of the membrane cleaning procedure is essential to improve the overall efficiency. In this work, a study of the factors affecting the ultrasound-assisted cleaning of an ultrafiltration ceramic membrane fouled by dye particles was carried out. The effect of transmembrane pressure (0.5, 1.5, 2.5 bar), cross-flow velocity (1, 2, 3 ms(-1)), ultrasound power level (40%, 70%, 100%) and ultrasound frequency mode (37, 80 kHz and mixed wave) on the cleaning efficiency was evaluated. The lowest frequency showed better results, although the best cleaning performance was obtained using the mixed wave mode. A Box-Behnken Design was used to find the optimal conditions for the cleaning procedure through a response surface study. The optimal operating conditions leading to the maximum cleaning efficiency predicted (32.19%) were found to be 1.1 bar, 3 ms(-1) and 100% of power level. Finally, the optimized response was compared to the efficiency of a chemical cleaning with NaOH solution, with and without the use of ultrasound. By using NaOH, cleaning efficiency nearly triples, and it improves up to 25% by adding ultrasound. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Ceramic membrane fouling during ultrafiltration of oil/water emulsions: Roles played by stabilization surfactants of oil droplets

    KAUST Repository

    Lu, Dongwei; Zhang, Tao; Ma, Jun

    2015-01-01

    of classical fouling models, and analysis of organic components rejected by the membrane. Furthermore, this mechanism was also verified by the existence of a steric effect and demulsification effect. Our finding suggests that ceramic membrane oppositely charged

  7. Effects of different pretreatments on the performance of ceramic ultrafiltration membrane during the treatment of oil sands tailings pond recycle water: a pilot-scale study.

    Science.gov (United States)

    Loganathan, Kavithaa; Chelme-Ayala, Pamela; El-Din, Mohamed Gamal

    2015-03-15

    Membrane filtration is an effective treatment method for oil sands tailings pond recycle water (RCW); however, membrane fouling and rapid decrease in permeate flux caused by colloids, organic matter, and bitumen residues present in the RCW hinder its successful application. This pilot-scale study investigated the impact of different pretreatment steps on the performance of a ceramic ultrafiltration (CUF) membrane used for the treatment of RCW. Two treatment trains were examined: treatment train 1 consisted of coagulant followed by a CUF system, while treatment train 2 included softening (Multiflo™ system) and coagulant addition, followed by a CUF system. The results indicated that minimum pretreatment (train 1) was required for almost complete solids removal. The addition of a softening step (train 2) provided an additional barrier to membrane fouling by reducing hardness-causing ions to negligible levels. More than 99% removal of turbidity and less than 20% removal of total organic carbon were achieved regardless of the treatment train used. Permeate fluxes normalized at 20 °C of 127-130 L/m(2) h and 111-118 L/m(2) h, with permeate recoveries of 90-93% and 90-94% were observed for the treatment trains 1 and 2, respectively. It was also found that materials deposited onto the membrane surface had an impact on trans-membrane pressure and influenced the required frequencies of chemically enhanced backwashes (CEBs) and clean-in-place (CIP) procedures. The CIP performed was successful in removing fouling and scaling materials such that the CUF performance was restored to baseline levels. The results also demonstrated that due to their low turbidity and silt density index values, permeates produced in this pilot study were suitable for further treatment by high pressure membrane processes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Support Services for Ceramic Fiber-Ceramic Matrix Composites

    Energy Technology Data Exchange (ETDEWEB)

    Hurley, J.P.

    2000-06-06

    built to simulate the Kellogg entrained-bed gasifier in use at the Southern Company Services Wilsonville facility, but at 1/10 of the firing rate. At the exit of the unit is a large candle filter vessel typically operated at approximately 1000 F (540 C) in which coupons of materials can be inserted to test their resistance to gasifier ash and gas corrosion. The system also has ports for testing of hydrogen separation membranes that are suitably contained in a pressure housing. In addition, NETL is operating the combustion and environmental research facility (CERF). In recent years, the 0.5 MMBtu/hr (0.5 x 10{sup 6} kJ/hr) CERF has served as a host for exposure of over 60 ceramic and alloy samples at ambient pressure as well as at 200 psig (for tubes). Samples have been inserted in five locations covering 1700-2600 F (930-1430 C), with exposures exceeding 1000 hours. In the present program, the higher priority metals are to be tested at 1500-1600 F (820-870 C) in one CERF location and near 1800-2000 F (980-1090 C) at other locations to compare results with those from the EERC tests.

  9. Randomized clinical trial of implant-supported ceramic-ceramic and metal-ceramic fixed dental prostheses: preliminary results.

    Science.gov (United States)

    Esquivel-Upshaw, Josephine F; Clark, Arthur E; Shuster, Jonathan J; Anusavice, Kenneth J

    2014-02-01

    The aim of this study was to determine the survival rates over time of implant-supported ceramic-ceramic and metal-ceramic prostheses as a function of core-veneer thickness ratio, gingival connector embrasure design, and connector height. An IRB-approved, randomized, controlled clinical trial was conducted as a single-blind pilot study involving 55 patients missing three teeth in either one or two posterior areas. These patients (34 women; 21 men; age range 52-75 years) were recruited for the study to receive a three-unit implant-supported fixed dental prosthesis (FDP). Two implants were placed for each of the 72 FDPs in the study. The implants (Osseospeed, Astra Tech), which were made of titanium, were grit blasted. A gold-shaded, custom-milled titanium abutment (Atlantis, Astra Tech), was secured to each implant body. Each of the 72 FDPs in 55 patients were randomly assigned based on one of the following options: (1) A. ceramic-ceramic (Yttria-stabilized zirconia core, pressable fluorapatite glass-ceramic, IPS e.max ZirCAD, and ZirPress, Ivoclar Vivadent) B. metal-ceramic (palladium-based noble alloy, Capricorn, Ivoclar Vivadent, with press-on leucite-reinforced glass-ceramic veneer, IPS InLine POM, Ivoclar Vivadent); (2) occlusal veneer thickness (0.5, 1.0, and 1.5 mm); (3) curvature of gingival embrasure (0.25, 0.5, and 0.75 mm diameter); and (4) connector height (3, 4, and 5 mm). FDPs were fabricated and cemented with dual-cure resin cement (RelyX, Universal Cement, 3M ESPE). Patients were recalled at 6 months, 1 year, and 2 years. FDPs were examined for cracks, fracture, and general surface quality. Recall exams of 72 prostheses revealed 10 chipping fractures. No fractures occurred within the connector or embrasure areas. Two-sided Fisher's exact tests showed no significant correlation between fractures and type of material system (p = 0.51), veneer thickness (p = 0.75), radius of curvature of gingival embrasure (p = 0.68), and connector height (p = 0

  10. Ceramic membrane development in NGK

    Energy Technology Data Exchange (ETDEWEB)

    Araki, Kiyoshi; Sakai, Hitoshi, E-mail: kinsakai@ngk.co.jp [Corporate R and D, NGK Insulators, Ltd., Nagoya 467-8530 (Japan)

    2011-05-15

    NGK Insulators, Ltd. was established in 1919 to manufacture the electric porcelain insulators for power transmission lines. Since then, our business has grown as one of the world-leading ceramics manufacturing companies and currently supply with the various environmentally-benign ceramic products to worldwide. In this paper, ceramic membrane development in NGK is described in detail. We have been selling ceramic microfiltration (MF) membranes and ultra-filtration (UF) membranes for many years to be used for solid/liquid separation in various fields such as pharmaceutical, chemical, food and semiconductor industries. In Corporate R and D, new ceramic membranes with sub-nanometer sized pores, which are fabricated on top of the membrane filters as support, are under development for gas and liquid/liquid separation processes.

  11. Ceramic membrane development in NGK

    Science.gov (United States)

    Araki, Kiyoshi; Sakai, Hitoshi

    2011-05-01

    NGK Insulators, Ltd. was established in 1919 to manufacture the electric porcelain insulators for power transmission lines. Since then, our business has grown as one of the world-leading ceramics manufacturing companies and currently supply with the various environmentally-benign ceramic products to worldwide. In this paper, ceramic membrane development in NGK is described in detail. We have been selling ceramic microfiltration (MF) membranes and ultra-filtration (UF) membranes for many years to be used for solid/liquid separation in various fields such as pharmaceutical, chemical, food and semiconductor industries. In Corporate R&D, new ceramic membranes with sub-nanometer sized pores, which are fabricated on top of the membrane filters as support, are under development for gas and liquid/liquid separation processes.

  12. Impeded solid state reactions and transformations in ceramic catalysts supports and catalysts

    Directory of Open Access Journals (Sweden)

    Ernő E. Kiss

    2012-12-01

    Full Text Available Impeded chemical reactions and impeded polymorphous transformation in materials are discussed, as desired effects, for stabilization of ceramic catalyst supports and ceramic based catalysts. This paper gives a short overview about the possibilities of slowing down the aging processes in ceramic catalyst supports and catalysts. Special attention is given to alumina and titania based catalysts.

  13. Ceramic wash-coat for catalyst support

    Science.gov (United States)

    Kulkarni, Anand A.; Subramanian, Ramesh; Sabol, Stephen M.

    2012-08-14

    A wash-coat (16) for use as a support for an active catalyst species (18) and a catalytic combustor component (10) incorporating such wash-coat. The wash-coat is a solid solution of alumina or alumina-based material (Al.sub.2O.sub.3-0-3 wt % La.sub.2O.sub.3) and a further oxide exhibiting a coefficient of thermal expansion that is lower than that exhibited by alumina. The further oxide may be silicon dioxide (2-30 wt % SiO.sub.2), zirconia silicate (2-30 wt % ZrSiO.sub.4), neodymium oxide (0-4 wt %), titania (Al.sub.2O.sub.3-3-40% TiO.sub.2) or alumina-based magnesium aluminate spinel (Al.sub.2O.sub.3-25 wt % MgO) in various embodiments. The active catalyst species may be palladium and a second metal in a concentration of 10-50% of the concentration of the palladium.

  14. The all-ceramic, inlay supported fixed partial denture. Part 1. Ceramic inlay preparation design: a literature review.

    Science.gov (United States)

    Thompson, M C; Thompson, K M; Swain, M

    2010-06-01

    The effect of cavity design is a controversial and underrated factor in the clinical success of ceramic inlays and inlay supported prosthesis. Many articles and studies have been conducted into the advantages and disadvantages of isolated aspects of preparation design, but lacking is a review of the most relevant papers which bring together a consensus on all the critical features. Hence, a review and analysis of cavity depth, width, preparation taper and internal line angles is warranted in our attempts to formulate preparation guidelines that will lead to clinically successful, all-ceramic inlay restorations and ceramic inlay supported prosthesis.

  15. Advances in Ceramic Supports for Polymer Electrolyte Fuel Cells

    Directory of Open Access Journals (Sweden)

    Oran Lori

    2015-08-01

    Full Text Available Durability of catalyst supports is a technical barrier for both stationary and transportation applications of polymer-electrolyte-membrane fuel cells. New classes of non-carbon-based materials were developed in order to overcome the current limitations of the state-of-the-art carbon supports. Some of these materials are designed and tested to exceed the US DOE lifetime goals of 5000 or 40,000 hrs for transportation and stationary applications, respectively. In addition to their increased durability, the interactions between some new support materials and metal catalysts such as Pt result in increased catalyst activity. In this review, we will cover the latest studies conducted with ceramic supports based on carbides, oxides, nitrides, borides, and some composite materials.

  16. Support influence on the properties of the alumina ceramic membranes

    International Nuclear Information System (INIS)

    Clar, C.; Scian, A.N.; Aglietti, E.F.

    2003-01-01

    The ceramic substrates used as supports for the formation of a top layer membrane must meet several requirements.Some of them are: have an average pore size and a suitable surface rugosity to obtain a homogenous top layer preventing the penetration of the membrane precursor particles into the support pores.This work analyzes the performance of the three α-Al 2 O 3 supports, with different average pore sizes and surface textures, for the formation of a membrane top layer by the dipcoating technique from colloids in suspension of aluminum basic acetate and later thermal treatment at 1000degC.The pore size distribution of the supports, the support-membrane systems and the top layer membrane was obtained by the mercury intrusion porosimetry technique.The microstructural differences of the supports and the top layer thickness were observed by MEB.It could be observed that for numerous deposits the membrane layer pore size obtained is independent on the support used and that the thickness of the last layer is lower for the greater pore size supports.The possibility of an intermediate layer between the support and the top layer was considered in every case

  17. On the use of ultrafiltration membranes in oily water separators

    Energy Technology Data Exchange (ETDEWEB)

    Tremblay, A.Y.; Nottegar, M. [Ottawa Univ., ON (Canada). Dept. of Chemical Engineering; Veinot, D.E. [Defence Research Establishment Atlantic, Halifax, NS (Canada)

    2000-07-01

    Laboratory studies were conducted on the use of ultrafiltration membranes for oil water purification from ships bilges. Bilge water is a complex and highly variable mixture of several components such as seawater, lubricating oil, greases, marine diesel fuel, hydraulic oil, detergents, metal oxides, corrosion inhibitors, asbestos and other wastes. This laboratory study examined the performance of ultrafiltration membranes when separating oily waste water of similar composition to that of bilge water. Ultrafiltration membranes are nanoporous materials produced from ceramic, polymeric or metallic substrates. The ability of the membrane to retain macromolecules, colloids, sub-micron particles and oil emulsions depends on the size of the nanopores. The best results in this study occurred when upper and lower bounds on the membrane pore size were found to exist. It was determined that ultrafiltration is a viable separation process for the treatment of bilge water for compliance with overboard discharge regulations. 7 refs., 1 tab., 3 figs.

  18. Porous ceramic materials for micro filtration processes I: Al2 O3 fabrication and characterization

    International Nuclear Information System (INIS)

    Salas K, J.; Reyes M, P.E.; Piderit A, G.

    1992-01-01

    Ceramic filters in separation processes are becoming more important every day. The use of these filters or membranes in the micro and ultrafiltration range, which origin goes back to the nuclear industry for uranium isotopes separation by gaseous diffusion and radioactive waste treatments, significantly improves some industrial processes efficiency. The present work describes the research done in the filters, or ceramic membrane supports fabrication field, the obtained operational results and their relation with the microstructure. (author)

  19. Comparative Study on Performance and Organic Fouling of ZrO2 Ceramic Membranes in Ultrafiltration of Synthetic Water and Wastewater Treatment Plant Effluent

    KAUST Repository

    Li, Cen

    2011-07-01

    Adsorption of organic matter on ceramic membrane can lead to hydraulic-irreversible fouling, which decreases the permeate flux and the cost-efficiency of membrane devices. In order to optimize the filtration process, detailed information is necessary about the organic fouling mechanisms on ceramic membranes. In this study, dead-end filtration experiments of both synthetic water and secondary effluent from a wastewater treatment plant (WWTP) were conducted on a ZrO2 ceramic membrane. The experiment results of synthetic water showed that humic acid (HA) was able to be adsorbed by the ZrO2 membrane and cause permeate flux decline; and that HA-tryptophan mixture, at the same DOC level, promoted the filtration flux decline; DOC removal in the case of HA-tryptophan was lower than that of HA alone. It seems that hydrophilic organic matter with low molecular weight have some specific contribution to the organic fouling of the ZrO2 membrane. The results also suggest that tryptophan molecules were preferentially adsorbed on the membrane at the beginning, exposing their hydrophobic sides which might further adsorb HA from the feed water. During the filtration of WWTP effluent, protein-like substances (mainly tryptophan-like) were also preferentially adsorbed on the membrane compared with humic-like ones in the initial few cycles of filtration. More humic-like substances were adsorbed in the following filtration cycles due to the increase of membrane hydrophobicity. A significant rise in hydraulic-irreversible flux decline was obtained by decreasing pH from near pHpzc to below pHpzc of the membrane. It suggests that a positively charged surface is preferred for HA adsorption. Ionic strength increase did not affect the filtration of HA, but it lessened the hydraulic-irreversible flux decline of HA-tryptophan filtration. The adsorption of HA-tryptophan can be attributed to outersphere interaction while HA adsorption is mainly caused by inner-sphere interaction. The results of

  20. Ultrafiltration to reuse laundering wash water

    DEFF Research Database (Denmark)

    Giagnorio, Mattia; Søtoft, Lene Fjerbæk; Tiraferri, Alberto

    2017-01-01

    Laundering industry consumes and discharges large amounts of water and surfactants, and the demand of surface active agents used for washing is increasing worldwide. Some of these substances are considered contaminants of emerging concern, as they persist in the environment. This work aimed...... at evaluating the feasibility of ultrafiltration as a method to treat the wash wastewater and possibly reuse the surfactant-rich permeate stream in laundry facilities. In particular, evaluation of surfactant recovery was performed through analysis of the permeate flux and properties obtained through polymeric...... and ceramic membranes. Wash water samples were collected at an industrial laundering facility for hospital linen and filtered through different ultrafiltration membranes with varying molecular weight cut-off. The critical micelle concentration of the detergent was quantified, and capillarity measurements were...

  1. Effect of interactions between Co(2+) and surface goethite layer on the performance of α-FeOOH coated hollow fiber ceramic ultrafiltration membranes.

    Science.gov (United States)

    Zhu, Zhiwen; Zhu, Li; Li, Jianrong; Tang, Jianfeng; Li, Gang; Hsieh, Yi-Kong; Wang, TsingHai; Wang, Chu-Fang

    2016-03-15

    The consideration of water energy nexus inspires the environmental engineering community to pursue a more sustainable strategy in the wastewater treatment. One potential response would be to enhance the performance of the low-pressure driven filtration system. To reach this objective, it is essential to have a better understanding regarding the surface interaction between the target substance and the surface of membrane. In this study, the hollow fiber ceramic membranes were coated with a goethite layer in order to enhance the Co(2+) rejection. Experimental results indicate that higher Co(2+) rejections are always accompanied with the significant reduction in the permeability. Based on the consideration of electroviscous effect, the surface interactions including the induced changes in viscosity, pore radius and Donnan effect in the goethite layer are likely responsible for the pH dependent behaviors in the rejection and permeability. These results could be valuable references to develop the filtration system with high rejection along with acceptable degree of permeability in the future. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. CROSS-FLOW ULTRAFILTRATION OF SECONDARY EFFLUENTS. MEMBRANE FOULING ANALYSIS

    Directory of Open Access Journals (Sweden)

    Luisa Vera

    2014-12-01

    Full Text Available The application of cross-flow ultrafiltration to regenerate secondary effluents is limited by membrane fouling. This work analyzes the influence of the main operational parameters (transmembrane pressure and cross-flow velocity about the selectivity and fouling observed in an ultrafiltration tubular ceramic membrane. The experimental results have shown a significant retention of the microcolloidal and soluble organic matter (52 – 54% in the membrane. The fouling analysis has defined the critical operational conditions where the fouling resistance is minimized. Such conditions can be described in terms of a dimensionless number known as shear stress number and its relationship with other dimensionless parameter, the fouling number.

  3. Ultrafiltration of pegylated proteins

    Science.gov (United States)

    Molek, Jessica R.

    There is considerable clinical interest in the use of "second-generation" therapeutics produced by conjugation of a native protein with various polymers including polyethylene glycol (PEG). PEG--protein conjugates, so-called PEGylated proteins, can exhibit enhanced stability, half-life, and bioavailability. One of the challenges in the commercial production of PEGylated proteins is the purification required to remove unreacted polymer, native protein, and in many cases PEGylated proteins with nonoptimal degrees of conjugation. The overall objective of this thesis was to examine the use of ultrafiltration for the purification of PEGylated proteins. This included: (1) analysis of size-based separation of PEGylated proteins using conventional ultrafiltration membranes, (2) use of electrically-charged membranes to exploit differences in electrostatic interactions, and (3) examination of the effects of PEGylation on protein fouling. The experimental results were analyzed using appropriate theoretical models, with the underlying physical properties of the PEGylated proteins evaluated using size exclusion chromatography, capillary electrophoresis, dynamic light scattering, and reverse phase chromatography. PEGylated proteins were produced by covalent attachment of activated PEG to a protein via primary amines on the lysine residues. A simple model was developed for the reaction kinetics, which was used to explore the effect of reaction conditions and mode of operation on the distribution of PEGylated products. The effective size of the PEGylated proteins was evaluated using size exclusion chromatography, with appropriate correlations developed for the size in terms of the molecular weight of the native protein and attached PEG. The electrophoretic mobility of the PEGylated proteins were evaluated by capillary electrophoresis with the data in good agreement with a simple model accounting for the increase in protein size and the reduction in the number of protonated amine

  4. A 3-year prospective study of implant-supported, single-tooth restorations of all-ceramic and metal-ceramic materials in patients with tooth agenesis.

    Science.gov (United States)

    Hosseini, Mandana; Worsaae, Nils; Schiødt, Morten; Gotfredsen, Klaus

    2013-10-01

    The purpose of this clinical study was to describe outcome variables of all-ceramic and metal-ceramic implant-supported, single-tooth restorations. A total of 59 patients (mean age: 27.9 years) with tooth agenesis and treated with 98 implant-supported single-tooth restorations were included in this study. Two patients did not attend baseline examination, but all patients were followed for 3 years. The implants supported 52 zirconia, 21 titanium and 25 gold alloy abutments, which retained 64 all-ceramic and 34 metal-ceramic crowns. At baseline and 3-year follow-up examinations, the biological outcome variables such as survival rate of implants, marginal bone level, modified Plaque Index (mPlI), modified Sulcus Bleeding Index (mBI) and biological complications were registered. The technical outcome variables included abutment and crown survival rate, marginal adaptation of crowns, cement excess and technical complications. The aesthetic outcome was assessed by using the Copenhagen Index Score, and the patient-reported outcomes were recorded using the OHIP-49 questionnaire. The statistical analyses were mainly performed by using mixed model of ANOVA for quantitative data and PROC NLMIXED for ordinal categorical data. The 3-year survival rate was 100% for implants and 97% for abutments and crowns. Significantly more marginal bone loss was registered at gold-alloy compared to zirconia abutments (P = 0.040). The mPlI and mBI were not significantly different at three abutment materials. The frequency of biological complications was higher at restorations with all-ceramic restorations than metal-ceramic crowns. Loss of retention, which was only observed at metal-ceramic crowns, was the most frequent technical complication, and the marginal adaptations of all-ceramic crowns were significantly less optimal than metal-ceramic crowns (P = 0.020). The professional-reported aesthetic outcome demonstrated significantly superior colour match of all-ceramic over metal-ceramic

  5. All-ceramic or metal-ceramic tooth-supported fixed dental prostheses (FDPs)? A systematic review of the survival and complication rates. Part I: Single crowns (SCs).

    Science.gov (United States)

    Sailer, Irena; Makarov, Nikolay Alexandrovich; Thoma, Daniel Stefan; Zwahlen, Marcel; Pjetursson, Bjarni Elvar

    2015-06-01

    To assess the 5-year survival of metal-ceramic and all-ceramic tooth-supported single crowns (SCs) and to describe the incidence of biological, technical and esthetic complications. Medline (PubMed), Embase, Cochrane Central Register of Controlled Trials (CENTRAL) searches (2006-2013) were performed for clinical studies focusing on tooth-supported fixed dental prostheses (FDPs) with a mean follow-up of at least 3 years. This was complimented by an additional hand search and the inclusion of 34 studies from a previous systematic review [1,2]. Survival and complication rates were analyzed using robust Poisson's regression models to obtain summary estimates of 5-year proportions. Sixty-seven studies reporting on 4663 metal-ceramic and 9434 all-ceramic SCs fulfilled the inclusion criteria. Seventeen studies reported on metal-ceramic crowns, and 54 studies reported on all-ceramic crowns. Meta-analysis of the included studies indicated an estimated survival rate of metal-ceramic SCs of 94.7% (95% CI: 94.1-96.9%) after 5 years. This was similar to the estimated 5-year survival rate of leucit or lithium-disilicate reinforced glass ceramic SCs (96.6%; 95% CI: 94.9-96.7%), of glass infiltrated alumina SCs (94.6%; 95% CI: 92.7-96%) and densely sintered alumina and zirconia SCs (96%; 95% CI: 93.8-97.5%; 92.1%; 95% CI: 82.8-95.6%). In contrast, the 5-year survival rates of feldspathic/silica-based ceramic crowns were lower (pceramic and zirconia crowns exhibited significantly lower survival rates in the posterior region (pceramic fractures than metal-ceramic SCs (pceramic SCs than for metal-ceramic SCs. Survival rates of most types of all-ceramic SCs were similar to those reported for metal-ceramic SCs, both in anterior and posterior regions. Weaker feldspathic/silica-based ceramics should be limited to applications in the anterior region. Zirconia-based SCs should not be considered as primary option due to their high incidence of technical problems. Copyright © 2015 Academy

  6. Synthesis of Functional Ceramic Supports by Ice Templating and Atomic Layer Deposition

    Directory of Open Access Journals (Sweden)

    Michaela Klotz

    2018-05-01

    Full Text Available In this work, we report an innovative route for the manufacturing of functional ceramic supports, by combining ice templating of yttria stabilized zirconia (YSZ and atomic layer deposition (ALD of Al2O3 processes. Ceramic YSZ monoliths are prepared using the ice-templating process, which is based on the controlled crystallization of water following a thermal gradient. Sublimation of the ice and the sintering of the material reveal the straight micrometer sized pores shaped by the ice crystal growth. The high temperature sintering allows for the ceramic materials to present excellent mechanical strength and porosities of 67%. Next, the conformality benefit of ALD is used to deposit an alumina coating at the surface of the YSZ pores, in order to obtain a functional material. The Al2O3 thin films obtained by ALD are 100 nm thick and conformally deposited within the macroporous ceramic supports, as shown by SEM and EDS analysis. Mercury intrusion experiments revealed a reduction of the entrance pore diameter, in line with the growth per cycle of 2 Å of the ALD process. In addition to the manufacture of the innovative ceramic nanomaterials, this article also describes the fine characterization of the coatings obtained using mercury intrusion, SEM and XRD analysis.

  7. Gradient composite metal-ceramic foam as supportive component for planar SOFCs and MIEC membranes

    International Nuclear Information System (INIS)

    Smorygo, Oleg; Mikutski, Vitali; Marukovich, Alexander; Sadykov, Vladislav; Usoltsev, Vladimir; Mezentseva, Natalia; Borodinecs, Anatolijs; Bobrenok, Oleg

    2011-01-01

    A novel approach to the design of planar gradient porous supports for the thin-film SOFCs and MIEC membranes is described. The support's thermal expansion is controlled by the creation of a two-component composite metal-ceramic foam structure. Thin MIEC membranes and SOFCs were prepared on the composite supports by the layerwise deposition of composite functional layers including complex fluorites and perovskites. Lab-scale studies demonstrated promising performance of both MIEC membrane and SOFC.

  8. Gradient composite metal-ceramic foam as supportive component for planar SOFCs and MIEC membranes

    Science.gov (United States)

    Smorygo, Oleg; Mikutski, Vitali; Marukovich, Alexander; Sadykov, Vladislav; Usoltsev, Vladimir; Mezentseva, Natalia; Borodinecs, Anatolijs; Bobrenok, Oleg

    2011-06-01

    A novel approach to the design of planar gradient porous supports for the thin-film SOFCs and MIEC membranes is described. The support's thermal expansion is controlled by the creation of a two-component composite metal-ceramic foam structure. Thin MIEC membranes and SOFCs were prepared on the composite supports by the layerwise deposition of composite functional layers including complex fluorites and perovskites. Lab-scale studies demonstrated promising performance of both MIEC membrane and SOFC.

  9. Sol-gel applications for ceramic membrane preparation

    Science.gov (United States)

    Erdem, I.

    2017-02-01

    Ceramic membranes possessing superior properties compared to polymeric membranes are more durable under severe working conditions and therefore their service life is longer. The ceramic membranes are composed of some layers. The support is the layer composed of coarser ceramic structure and responsible for mechanical durability under filtration pressure and it is prepared by consolidation of ceramic powders. The top layer is composed of a finer ceramic micro-structure mainly responsible for the separation of components present in the fluid to be filtered and sol-gel method is a versatile tool to prepare such a tailor-made ceramic filtration structure with finer pores. Depending on the type of filtration (e.g. micro-filtration, ultra-filtration, nano-filtration) aiming separation of components with different sizes, sols with different particulate sizes should be prepared and consolidated with varying precursors and preparation conditions. The coating of sol on the support layer and heat treatment application to have a stable ceramic micro-structure are also important steps determining the final properties of the top layer. Sol-gel method with various controllable parameters (e.g. precursor type, sol formation kinetics, heat treatment conditions) is a practical tool for the preparation of top layers of ceramic composite membranes with desired physicochemical properties.

  10. Influence of the supporting die structures on the fracture strength of all-ceramic materials.

    Science.gov (United States)

    Yucel, Munir Tolga; Yondem, Isa; Aykent, Filiz; Eraslan, Oğuz

    2012-08-01

    This study investigated the influence of the elastic modulus of supporting dies on the fracture strengths of all-ceramic materials used in dental crowns. Four different types of supporting die materials (dentin, epoxy resin, brass, and stainless steel) (24 per group) were prepared using a milling machine to simulate a mandibular molar all-ceramic core preparation. A total number of 96 zirconia cores were fabricated using a CAD/CAM system. The specimens were divided into two groups. In the first group, cores were cemented to substructures using a dual-cure resin cement. In the second group, cores were not cemented to the supporting dies. The specimens were loaded using a universal testing machine at a crosshead speed of 0.5 mm/min until fracture occurred. Data were statistically analyzed using two-way analysis of variance and Tukey HSD tests (α = 0.05). The geometric models of cores and supporting die materials were developed using finite element method to obtain the stress distribution of the forces. Cemented groups showed statistically higher fracture strength values than non-cemented groups. While ceramic cores on stainless steel dies showed the highest fracture strength values, ceramic cores on dentin dies showed the lowest fracture strength values among the groups. The elastic modulus of the supporting die structure is a significant factor in determining the fracture resistance of all-ceramic crowns. Using supporting die structures that have a low elastic modulus may be suitable for fracture strength tests, in order to accurately reflect clinical conditions.

  11. Whey pretreatments before ultrafiltration

    Directory of Open Access Journals (Sweden)

    Tuomo Tupasela

    1994-09-01

    Full Text Available Whey is a by-product of cheesemaking. Whey dry matter contains mainly lactose, but also valuable whey proteins. The aim of this study was to develop improvements to whey protein membrane isolation processes. In our trials CaCl2 -added, pH-adjusted and heat-treated wheys were found to have MF (microfiltration permeate fluxes about 30% higher than in untreated MF whey. The total solids and protein content of the MF permeates decreased compared to the original wheys. UF (ultrafiltration trials were conducted using MF whey to compare it with centrifugally separated whey. The MF whey consistently maintained an UF flux about 1.5 to 2.5 times higher than that of the separated whey. Differently treated MF whey UF permeate fluxes also showed a difference. With CaCl2 addition, pH adjustment and heat treatment, the UF permeate fluxes were about 20 to 40% higher than when only MF was used. The total solids content decreased in each trial. The protein content of the UF concentrate also decreased compared to the MF permeate. The (β-lg (β-lactoglobulin and α-la (α-lactalbumin content was almost the same in UF concentrates as in MF permeates.

  12. design of ceramic membrane supports: permeability, tensile strength and stress

    NARCIS (Netherlands)

    Biesheuvel, Pieter Maarten; Biesheuvel, P.M.; Verweij, H.

    1999-01-01

    A membrane support provides mechanical strength to a membrane top layer to withstand the stress induced by the pressure difference applied over the entire membrane and must simultaneously have a low resistance to the filtrate flow. In this paper an experimental and a theoretical approach toward the

  13. Electro-ultrafiltration of industrial enzyme solutions

    DEFF Research Database (Denmark)

    Enevoldsen, Ann Dorrit; Hansen, Erik Børresen; Jonsson, Gunnar Eigil

    2007-01-01

    To reduce the problems with fouling and concentration polarization during crossflow ultrafiltration of industrial enzyme solutions an electric field is applied across the membrane. The filtration performance during electro-ultrafiltration (EUF) has been tested with several enzymes. Results show...

  14. Planar, Polysilazane?Derived Porous Ceramic Supports for Membrane and Catalysis Applications

    OpenAIRE

    Konegger, Thomas; Williams, Lee F.; Bordia, Rajendra K.

    2015-01-01

    Porous, silicon carbonitride?based ceramic support structures for potential membrane and catalysis applications were generated from a preceramic polysilazane precursor in combination with spherical, ultrahigh?molecular weight polyethylene microparticles through a sacrificial filler approach. A screening evaluation was used for the determination of the impact of both porogen content and porogen size on pore structure, strength, and permeability characteristics of planar specimens. By optimizin...

  15. Fracture Resistance and Mode of Failure of Ceramic versus Titanium Implant Abutments and Single Implant-Supported Restorations.

    Science.gov (United States)

    Sghaireen, Mohd G

    2015-06-01

    The material of choice for implant-supported restorations is affected by esthetic requirements and type of abutment. This study compares the fracture resistance of different types of implant abutments and implant-supported restorations and their mode of failure. Forty-five Oraltronics Pitt-Easy implants (Oraltronics Dental Implant Technology GmbH, Bremen, Germany) (4 mm diameter, 10 mm length) were embedded in clear autopolymerizing acrylic resin. The implants were randomly divided into three groups, A, B and C, of 15 implants each. In group A, titanium abutments and metal-ceramic crowns were used. In group B, zirconia ceramic abutments and In-Ceram Alumina crowns were used. In group C, zirconia ceramic abutments and IPS Empress Esthetic crowns were used. Specimens were tested to failure by applying load at 130° from horizontal plane using an Instron Universal Testing Machine. Subsequently, the mode of failure of each specimen was identified. Fracture resistance was significantly different between groups (p Empress crowns supported by zirconia abutments had the lowest fracture loads (p = .000). Fracture modes of metal-ceramic crowns supported by titanium abutments included screw fracture and screw bending. Fracture of both crown and abutment was the dominant mode of failure of In-Ceram/IPS Empress crowns supported by zirconia abutments. Metal-ceramic crowns supported by titanium abutments were more resistant to fracture than In-Ceram crowns supported by zirconia abutments, which in turn were more resistant to fracture than IPS Empress crowns supported by zirconia abutments. In addition, failure modes of restorations supported by zirconia abutments were more catastrophic than those for restorations supported by titanium abutments. © 2013 Wiley Periodicals, Inc.

  16. Review. Freeze-casting: Fabrication of highly porous and hierarchical ceramic supports for energy applications

    Energy Technology Data Exchange (ETDEWEB)

    Gaudillere, C.; Serra, J. M.

    2016-05-01

    The manufacture of structured ceramic porous support knows an important boom since more than a decade with the development of new shaping techniques. Among the most promising ones, the freeze-casting also called Ice-Tem plating allows the fabrication of ceramic parts exhibiting high porosity (>50%) and vertically aligned and hierarchically organized pores. Such structures were firstly conceived for biomedical applications like bone substitute and tissue engineering, but the distinctive features of freeze-cast structures have attracted the attention of diverse scientific fields, especially in high temperature ceramic-based energy production systems. Indeed, technologies like (a) Solid Oxide Fuel Cell (SOFC) and Electrolyser Cell (SOEC), (b) gas separation (O{sub 2}, H{sub 2}) by asymmetric supported membranes based on mixed ionic and electronic conductors (MIEC) or hydrogen-permeable metals, and (c) Catalytic Membrane Reactor (CMR) systems present a porous component in their physical structure. This latest, presenting a tortuous pathway for gas access and as a consequence, a high transport limitation, is known to be a limiting component for the operation at high flow streams that would enable to reach industrial target. (Author)

  17. Microstructured hollow fibers for ultrafiltration

    NARCIS (Netherlands)

    Culfaz, Pmar Zeynep; Culfaz, P.Z.; Rolevink, Hendrikus H.M.; van Rijn, C.J.M.; Lammertink, Rob G.H.; Wessling, Matthias

    2010-01-01

    Hollow fiber ultrafiltration membranes with a corrugated outer microstructure were prepared from a PES/PVP blend. The effect of spinning parameters such as air gap, take-up speed, polymer dope viscosity and coagulation value on the microstructure and membrane characteristics was investigated. Fibers

  18. Halloysite nanotube-based electrospun ceramic nanofibre mat: a novel support for zeolite membranes

    Science.gov (United States)

    Chen, Zhuwen; Zeng, Jiaying; Lv, Dong; Gao, Jinqiang; Zhang, Jian; Bai, Shan; Li, Ruili; Hong, Mei; Wu, Jingshen

    2016-12-01

    Some key parameters of supports such as porosity, pore shape and size are of great importance for fabrication and performance of zeolite membranes. In this study, we fabricated millimetre-thick, self-standing electrospun ceramic nanofibre mats and employed them as a novel support for zeolite membranes. The nanofibre mats were prepared by electrospinning a halloysite nanotubes/polyvinyl pyrrolidone composite followed by a programmed sintering process. The interwoven nanofibre mats possess up to 80% porosity, narrow pore size distribution, low pore tortuosity and highly interconnected pore structure. Compared with the commercial α-Al2O3 supports prepared by powder compaction and sintering, the halloysite nanotube-based mats (HNMs) show higher flux, better adsorption of zeolite seeds, adhesion of zeolite membranes and lower Al leaching. Four types of zeolite membranes supported on HNMs have been successfully synthesized with either in situ crystallization or a secondary growth method, demonstrating good universality of HNMs for supporting zeolite membranes.

  19. Freeze-casting: Fabrication of highly porous and hierarchical ceramic supports for energy applications

    Directory of Open Access Journals (Sweden)

    Cyril Gaudillere

    2016-03-01

    The aim of this paper is to give an overview of the freeze-casting ceramic shaping method and to show how its implementation could be useful for several energy applications where key components comprise a porous scaffold. A detailed presentation of the freeze-casting process and of the characteristics of the resulting porous parts is firstly given. The characteristic of freeze-cast parts and the drawbacks of conventional porous scaffolds existing in energy applications are drawn in order to highlight the expected beneficial effect of this new shaping technique as possible substitute to the conventional ones. Finally, a review of the state of the art freeze-cast based energy applications developed up to now and expected to be promising is given to illustrate the large perspectives opened by the implementation of the freeze-casting of ceramics for energy fields. Here we suggest discussing about the feasibility of incorporate freeze-cast porous support in high temperature ceramic-based energy applications.

  20. Active Elastic Support/Dry Friction Damper with Piezoelectric Ceramic Actuator

    Directory of Open Access Journals (Sweden)

    Liao Mingfu

    2014-01-01

    Full Text Available The basic operation principle of elastic support/dry friction damper in rotor system was introduced and the unbalance response of the rotor with elastic support/dry friction damper was analyzed theoretically. Based on the previous structure using an electromagnet as actuator, an active elastic support/dry friction damper using piezoelectric ceramic actuator was designed and its effectiveness of reducing rotor vibration when rotor traverses its critical speed and blade-out event happened was experimentally verified. The experimental results show that the active elastic support/dry friction damper with piezoelectric ceramic actuator can significantly reduce vibration in rotor system; the vibration amplitude of the rotor in critical speed region decreased more than 2 times, and the active damper can protect the rotor when a blade-out event happened, so the rotor can traverse the critical speed and shut down smoothly. In addition, the structure is much simpler than the previous, the weight was reduced by half and the power consumption was only 5 W.

  1. A novel processing approach for free-standing porous non-oxide ceramic supports from polycarbosilane and polysilazane precursors

    OpenAIRE

    Konegger, Thomas; Patidar, Rajesh; Bordia, Rajendra K.

    2015-01-01

    In this contribution, a low-pressure/low-temperature casting technique for the preparation of novel free-standing macrocellular polymer-derived ceramic support structures is presented. Preceramic polymers (polycarbosilane and poly(vinyl)silazane) are combined with sacrificial porogens (ultra-high molecular weight polyethylene microbeads) to yield porous ceramic materials in the Si?C or Si?C?N systems, exhibiting well-defined pore structures after thermal conversion. The planar-disc-type speci...

  2. Determination of porosity in supports for ceramic membranes of titanium dioxide by gamma spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Siciliano, Umberto C.C.S.; Oliveira, Elizabeth E.M.; Brandão, Luís E.B.; Carvalho, Paulo V.R., E-mail: ucsiciliano@gmail.com, E-mail: eemo@ien.gov.br, E-mail: brandao@ien.gov.br, E-mail: paulov@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    Membrane separation processes (MSP) have been widely used to fractionate, concentrate and purity solutions, such as: food industry, pharmaceutical, water desalination and for treatment of the radioactive liquid waste in the nuclear industry. The MSP are more economical than traditional methods because most of them are athermic. Increased membrane application has led to the expansion of the manufacturing technology knowledge base, resulting in membranes with high permeability, improved selectivity and long-term stability. The demand for high operating temperatures and chemical resistance have stimulated the development of inorganic structures, mainly porous ceramics. The materials most used to obtain ceramic membranes are oxides like Ab0{sub 3}, Si0{sub 2}, Zr0{sub 2} and Ti0{sub 2} or combination of these. Despite the favorable characteristics, ceramic membranes has not been applied extensively, mainly due to the difficulty of obtaining porous structures without cracks and with adequate pore size. The objective of this work is obtain a support of titanium oxide using potato starch as a pore former. The titanium oxide used is commercial, with average particle size of 0.13 μm. Three suspensions were prepared containing 0,5 and 10 % of the potato starch and the drying in spray dryer, obtaining a homogeneous and granulated powder, with flow ability suitable for compaction. The supports were uniaxial pressing with l.5 kgf.cm{sup -2} and sintering at temperatures of 1050, 1100 and 1150 °C for 1h in oven resistance. The results showed that the porosity obtained by gamma ray transmission method was approximately 50%. This value is within range for applications as membrane support. (author)

  3. Self-supported ceramic substrates with directional porosity by mold freeze casting

    DEFF Research Database (Denmark)

    Gurauskis, Jonas; Graves, Christopher R.; Moreno, R.

    2016-01-01

    in a mold and applying directional freeze casting. Use of optimized suspension, cryoprotector additive and mold proved to deliver defect free ceramic films with high dimensional control. Microstructure analysis demonstrated the formation of desirable aligned porosity at macro-structural scale and resulted...... to be highly dependent on colloidal behaviour and freeze casting conditions. Manufactured green films were joined by lamination at room temperature and sintered to obtain symmetrical cells consisting of two porous self-supported substrate electrodes (∼420 μm) and dense yttria stabilized zirconia electrolyte...

  4. Gas Separation Properties of Polyimide Thin Films on Ceramic Supports for High Temperature Applications.

    Science.gov (United States)

    Escorihuela, Sara; Tena, Alberto; Shishatskiy, Sergey; Escolástico, Sonia; Brinkmann, Torsten; Serra, Jose Manuel; Abetz, Volker

    2018-03-07

    Novel selective ceramic-supported thin polyimide films produced in a single dip coating step are proposed for membrane applications at elevated temperatures. Layers of the polyimides P84 ® , Matrimid 5218 ® , and 6FDA-6FpDA were successfully deposited onto porous alumina supports. In order to tackle the poor compatibility between ceramic support and polymer, and to get defect-free thin films, the effect of the viscosity of the polymer solution was studied, giving the entanglement concentration (C*) for each polymer. The C* values were 3.09 wt. % for the 6FDA-6FpDA, 3.52 wt. % for Matrimid ® , and 4.30 wt. % for P84 ® . A minimum polymer solution concentration necessary for defect-free film formation was found for each polymer, with the inverse order to the intrinsic viscosities (P84 ® ≥ Matrimid ® > 6FDA-6FpDA). The effect of the temperature on the permeance of prepared membranes was studied for H₂, CH₄, N₂, O₂, and CO₂. As expected, activation energy of permeance for hydrogen was higher than for CO₂, resulting in H₂/CO₂ selectivity increase with temperature. More densely packed polymers lead to materials that are more selective at elevated temperatures.

  5. Gas Separation Properties of Polyimide Thin Films on Ceramic Supports for High Temperature Applications

    Directory of Open Access Journals (Sweden)

    Sara Escorihuela

    2018-03-01

    Full Text Available Novel selective ceramic-supported thin polyimide films produced in a single dip coating step are proposed for membrane applications at elevated temperatures. Layers of the polyimides P84®, Matrimid 5218®, and 6FDA-6FpDA were successfully deposited onto porous alumina supports. In order to tackle the poor compatibility between ceramic support and polymer, and to get defect-free thin films, the effect of the viscosity of the polymer solution was studied, giving the entanglement concentration (C* for each polymer. The C* values were 3.09 wt. % for the 6FDA-6FpDA, 3.52 wt. % for Matrimid®, and 4.30 wt. % for P84®. A minimum polymer solution concentration necessary for defect-free film formation was found for each polymer, with the inverse order to the intrinsic viscosities (P84® ≥ Matrimid® >> 6FDA-6FpDA. The effect of the temperature on the permeance of prepared membranes was studied for H2, CH4, N2, O2, and CO2. As expected, activation energy of permeance for hydrogen was higher than for CO2, resulting in H2/CO2 selectivity increase with temperature. More densely packed polymers lead to materials that are more selective at elevated temperatures.

  6. Ultrafiltration evaluation with depleted uranium oxide

    International Nuclear Information System (INIS)

    Weisbrod, K.R.; Schake, A.R.; Morgan, A.N.; Purdy, G.M.; Martinez, H.E.; Nelson, T.O.

    1998-03-01

    Scientists at the Los Alamos National Laboratory Plutonium Facility are using electrodissolution in neutral to alkaline solutions to decontaminate oralloy parts that have surface plutonium contamination. Ultrafiltration of the electrolyte stream removes precipitate so that the electrolyte stream to the decontamination fixture is precipitate free. This report describes small-scale laboratory ultrafiltration experiments that the authors performed to determine conditions necessary for full-scale operation of an ultrafiltration module. Performance was similar to what they observed in the ferric hydroxide system. At 12 psi transmembrane pressure, a shear rate of 12,000 sec -1 was sufficient to sustain membrane permeability. Ultrafiltration of uranium(VI) oxide appears to occur as easily as ultrafiltration of ferric hydroxide. Considering the success reported in this study, the authors plan to add ultrafiltration to the next decontamination system for oralloy parts

  7. Planar, Polysilazane-Derived Porous Ceramic Supports for Membrane and Catalysis Applications.

    Science.gov (United States)

    Konegger, Thomas; Williams, Lee F; Bordia, Rajendra K

    2015-10-01

    Porous, silicon carbonitride-based ceramic support structures for potential membrane and catalysis applications were generated from a preceramic polysilazane precursor in combination with spherical, ultrahigh-molecular weight polyethylene microparticles through a sacrificial filler approach. A screening evaluation was used for the determination of the impact of both porogen content and porogen size on pore structure, strength, and permeability characteristics of planar specimens. By optimizing both the composition as well as cross-linking parameters, maximum characteristic biaxial flexural strengths of 65 MPa and porosities of 42% were achieved. The evolution of an interconnected, open-pore network during thermal porogen removal and conversion of the preceramic polymer led to air permeabilities in the order of 10 -14 m 2 . The materials were further exposed to long-term heat treatments to demonstrate the stability of properties after 100 h at 800°C in oxidizing, inert, and reducing environments. The determined performance, in combination with the versatile preparation method, illustrates the feasibility of this processing approach for the generation of porous ceramic support structures for applications at elevated temperatures in a variety of fields, including membrane and catalysis science.

  8. Ceramic-supported thin PVA pervaporation membranes combining high flux and high selectivity : contradicting the flux-selectivity paradigm

    NARCIS (Netherlands)

    Peters, T.A.; Poeth, C.H.S.; Benes, N.E.; Buijs, H.C.W.M.; Vercauteren, F.F.; Keurentjes, J.T.F.

    2006-01-01

    Thin, high-flux and highly selective cross-linked poly(vinyl)alcohol waterselective layers have been prepared on top of hollow fibre ceramic supports. The supports consist of an alpha-Al2O3 hollow fibre substrate and an intermediate gamma-Al2O3 layer, which provides a sufficiently smooth surface for

  9. Tubular solid oxide fuel cells with porous metal supports and ceramic interconnections

    Science.gov (United States)

    Huang, Kevin [Export, PA; Ruka, Roswell J [Pittsburgh, PA

    2012-05-08

    An intermediate temperature solid oxide fuel cell structure capable of operating at from 600.degree. C. to 800.degree. C. having a very thin porous hollow elongated metallic support tube having a thickness from 0.10 mm to 1.0 mm, preferably 0.10 mm to 0.35 mm, a porosity of from 25 vol. % to 50 vol. % and a tensile strength from 700 GPa to 900 GPa, which metallic tube supports a reduced thickness air electrode having a thickness from 0.010 mm to 0.2 mm, a solid oxide electrolyte, a cermet fuel electrode, a ceramic interconnection and an electrically conductive cell to cell contact layer.

  10. All-ceramic or metal-ceramic tooth-supported fixed dental prostheses (FDPs)? A systematic review of the survival and complication rates. Part II: Multiple-unit FDPs.

    Science.gov (United States)

    Pjetursson, Bjarni Elvar; Sailer, Irena; Makarov, Nikolay Alexandrovich; Zwahlen, Marcel; Thoma, Daniel Stefan

    2015-06-01

    To assess the 5-year survival of metal-ceramic and all-ceramic tooth-supported fixed dental prostheses (FDPs) and to describe the incidence of biological, technical and esthetic complications. Medline (PubMed), Embase and Cochrane Central Register of Controlled Trials (CENTRAL) searches (2006-2013) were performed for clinical studies focusing on tooth-supported FDPs with a mean follow-up of at least 3 years. This was complemented by an additional hand search and the inclusion of 10 studies from a previous systematic review [1]. Survival and complication rates were analyzed using robust Poisson's regression models to obtain summary estimates of 5-year proportions. Forty studies reporting on 1796 metal-ceramic and 1110 all-ceramic FDPs fulfilled the inclusion criteria. Meta-analysis of the included studies indicated an estimated 5-year survival rate of metal-ceramic FDPs of 94.4% (95% CI: 91.2-96.5%). The estimated survival rate of reinforced glass ceramic FDPs was 89.1% (95% CI: 80.4-94.0%), the survival rate of glass-infiltrated alumina FDPs was 86.2% (95% CI: 69.3-94.2%) and the survival rate of densely sintered zirconia FDPs was 90.4% (95% CI: 84.8-94.0%) in 5 years of function. Even though the survival rate of all-ceramic FDPs was lower than for metal-ceramic FDPs, the differences did not reach statistical significance except for the glass-infiltrated alumina FDPs (p=0.05). A significantly higher incidence of caries in abutment teeth was observed for densely sintered zirconia FDPs compared to metal-ceramic FDPs. Significantly more framework fractures were reported for reinforced glass ceramic FDPs (8.0%) and glass-infiltrated alumina FDPs (12.9%) compared to metal-ceramic FDPs (0.6%) and densely sintered zirconia FDPs (1.9%) in 5 years in function. However, the incidence of ceramic fractures and loss of retention was significantly (p=0.018 and 0.028 respectively) higher for densely sintered zirconia FDPs compared to all other types of FDPs. Survival rates of all

  11. A study of colloid-enhanced ultrafiltration. Final report, March 1984--December 1993

    Energy Technology Data Exchange (ETDEWEB)

    Scamehorn, J.F.; Christian, S.D.

    1994-02-01

    Over the past nine years of funding by DOE Office of Basic Energy Sciences, the authors have developed a whole family of methods under the umbrella of colloid-enhanced ultrafiltration techniques. These methods can be used for removal of either dissolved organics or multivalent ions from water or both simultaneously. They have gone from very fundamental studies of the ultrafiltration process to a field test using actual polluted groundwater. The orientation of this research has been the ultimate development of a workable, economical process. To do this, the authors have tried to understand the underlying fundamental phenomena involved in the separation and in potential solutions to technological bottlenecks and developed new scientific knowledge in the process. However, the thrust of the investigations have been focused on bringing the technology to a successful adoption by industry. This report summarizes the following: micellar-enhanced ultrafiltration; polyelectrolyte-enhanced ultrafiltration; ion-expulsion ultrafiltration; ligand-modified micellar-enhanced ultrafiltration; polyelectrolyte/surfactant-enhanced ultrafiltration, supporting research, and relation to energy. 61 refs.

  12. Supportability of a High-Yield-Stress Slurry in a New Stereolithography-Based Ceramic Fabrication Process

    Science.gov (United States)

    He, Li; Song, Xuan

    2018-03-01

    In recent years, ceramic fabrication using stereolithography (SLA) has gained in popularity because of its high accuracy and density that can be achieved in the final part of production. One of the key challenges in ceramic SLA is that support structures are required for building overhanging features, whereas removing these support structures without damaging the components is difficult. In this research, a suspension-enclosing projection-stereolithography process is developed to overcome this challenge. This process uses a high-yield-stress ceramic slurry as the feedstock material and exploits the elastic force of the material to support overhanging features without the need for building additional support structures. Ceramic slurries with different solid loadings are studied to identify the rheological properties most suitable for supporting overhanging features. An analytical model of a double doctor-blade module is established to obtain uniform and thin recoating layers from a high-yield-stress slurry. Several test cases highlight the feasibility of using a high-yield-stress slurry to support overhanging features in SLA.

  13. THE MUNICIPAL SEWAGE TREATMENT PLANT EFFLUENT POLISHING IN ULTRAFILTRATION

    Directory of Open Access Journals (Sweden)

    Mariusz Dudziak

    2017-08-01

    Full Text Available The effluent from the municipal sewage treatment plant was comparatively treated in the ultrafiltration process using ceramic and polymer membranes. Filtration was carried out in the cross-flow system under the conditions of the transmembrane process pressure 0.1 MPa - the ceramic membrane and 0.2 MPa – the polymer membrane at a temperature of 20°C. The effectiveness of the process had been assessed by various physical and chemical analyses (pH, turbidity, color, absorbance, TOC and phenol index. There was included the toxicological assessment (by applying as an indicator organism the bioluminescence bacteria Aliivibrio fischeri and microbiological assessment of tested samples. During filtration there was studied the hydraulic efficiency of membranes. Is was specified, that the efficiency of the process depends on the conditions of membrane filtration, wherein the better effects of the removal of organic pollutants had been noted in the case of polymer membrane than ceramic membrane. However, the polymer membrane, in the comparison to the ceramic membrane, was more susceptible to pore blocking, which caused the reduction of hydraulic efficiency. Regardless of what type of membrane the permeats were not toxic and did not contain microorganisms.

  14. A 3-year prospective study of implant-supported, single-tooth restorations of all-ceramic and metal-ceramic materials in patients with tooth agenesis

    DEFF Research Database (Denmark)

    Hosseini, Mandana; Worsaae, Nils; Schiødt, Morten

    2013-01-01

    -tooth restorations were included in this study. Two patients did not attend baseline examination, but all patients were followed for 3 years. The implants supported 52 zirconia, 21 titanium and 25 gold alloy abutments, which retained 64 all-ceramic and 34 metal-ceramic crowns. At baseline and 3-year follow......-up examinations, the biological outcome variables such as survival rate of implants, marginal bone level, modified Plaque Index (mPlI), modified Sulcus Bleeding Index (mBI) and biological complications were registered. The technical outcome variables included abutment and crown survival rate, marginal adaptation...... and PROC NLMIXED for ordinal categorical data. RESULTS: The 3-year survival rate was 100% for implants and 97% for abutments and crowns. Significantly more marginal bone loss was registered at gold-alloy compared to zirconia abutments (P = 0.040). The mPlI and mBI were not significantly different at three...

  15. Waste-to-resource preparation of a porous ceramic membrane support featuring elongated mullite whiskers with enhanced porosity and permeance

    NARCIS (Netherlands)

    Zhu, Li; Dong, Yingchao; Hampshire, Stuart; Cerneaux, Sophie; Winnubst, Aloysius J.A.

    2015-01-01

    Different from traditional particle packing structure, a porous structure of ceramic membrane support was fabricated, featuring elongated mullitewhiskers with enhanced porosity, permeance and sufficient mechanical strength. The effect of additives (MoO3and AlF3) and sintering procedureon open

  16. Reaction-sintered porous mineral-based mullite ceramic membrane supports made from recycled materials.

    Science.gov (United States)

    Dong, Yingchao; Zhou, Jian-Er; Lin, Bin; Wang, Yongqing; Wang, Songlin; Miao, Lifeng; Lang, Ying; Liu, Xingqin; Meng, Guangyao

    2009-12-15

    Bulk porous mullite supports for ceramic membranes were prepared directly using a mixture of industrial waste fly ash and bauxite by dry-pressing, followed by sintering between 1200 and 1550 degrees C. The effects of sintering temperature on the phase composition and shrinkage percent of porous mullite were studied. The XRD results indicate that secondary mullitization reaction took place above 1200 degrees C, and completed at 1450 degrees C. During sintering, the mixture samples first shrunk, then expanded abnormally between 1326 and 1477 degrees C, and finally shrunk again above 1477 degrees C. This unique volume self-expansion is ascribed to the secondary mullitization reaction between bauxite and fly ash. More especially, the micro-structural variations induced by this self-expansion sintering were verified by SEM, porosity, pore size distribution and nitrogen gas permeation flux. During self-expansion sintering, with increasing temperature, an abnormal increase in both open porosity and pore size is observed, which also results in the increase of nitrogen gas flux. The mineral-based mullite supports with increased open porosity were obtained. Furthermore, the sintered porous mullite membrane supports were characterized in terms of thermal expansion co-efficient and mechanical strength.

  17. Evaluation of Ultrafiltration for Spacecraft Water Reuse

    Science.gov (United States)

    Pickering, Karen D.; Wiesner, Mark R.

    2001-01-01

    Ultrafiltration is examined for use as the first stage of a primary treatment process for spacecraft wastewater. It is hypothesized that ultrafiltration can effectively serve as pretreatment for a reverse osmosis system, removing the majority of organic material in a spacecraft wastewater. However, it is believed that the interaction between the membrane material and the surfactant found in the wastewater will have a significant impact on the fouling of the ultrafiltration membrane. In this study, five different ultrafiltration membrane materials are examined for the filtration of wastewater typical of that expected to be produced onboard the International Space Station. Membranes are used in an unstirred batch cell. Flux, organic carbon rejection, and recovery from fouling are measured. The results of this evaluation will be used to select the most promising membranes for further study.

  18. The evaluation of hollow-fiber ultrafiltration and celite concentration of enteroviruses, adenoviruses and bacteriophage from different water matrices

    Data.gov (United States)

    U.S. Environmental Protection Agency — The data to support the evaluation of hollow-fiber ultrafiltration and celite concentration of enteroviruses, adenoviruses and bacteriophage from different water...

  19. Retention of implant-supported zirconium oxide ceramic restorations using different luting agents.

    Science.gov (United States)

    Nejatidanesh, Farahnaz; Savabi, Omid; Shahtoosi, Mojtaba

    2013-08-01

    The aim of this study was to evaluate the retention value of implant-supported zirconium oxide ceramic copings using different luting agents. Twenty ITI solid abutments of 5.5 mm height and ITI implant analogs were mounted vertically into autopolymerizing acrylic resin blocks. Ninety zirconium oxide copings (Cercon, Degudent) with a loop on the occlusal portion were made. All samples were airborne particle abraded with 110 μm Al₂O₃ and luted using different types of luting agents: resin cements (Clearfil SA, Panavia F2.0, Fuji Plus), conventional cements (Fleck's, Poly F, Fuji I), and temporary cements (Temp Bond, GC free eugenol, TempSpan) with a load of 5 Kg. (N = 10) All copings were incubated at 37°C for 24 h and conditioned in artificial saliva for 1 week, and thermal cycled for 5000 cycles 5-55°C with a 30-s dwell time. The dislodging force of the copings along the long axis of the implant-abutment complex was recorded using universal testing machine with 5 mm/min crosshead speed. Data were subjected to Kruskal-Wallis (α = 0.05) and Mann-Whitney tests with Bonferroni step down correction (α = 0.001). There was significant difference between the mean rank retention values of different luting agents (P zirconium oxide restorations. © 2011 John Wiley & Sons A/S.

  20. Development of ceramic support the base of cordierite for one-side welding

    International Nuclear Information System (INIS)

    Almeida, L.L.P. de; Vieira, C.M.F.; Paranhos, R.P.R.; Tatagiba, L.C.S.

    2009-01-01

    This work has as objective develops ceramic backing for the execution of one side welds in steel. The backing consists the mixture of refractory mineral (Cordierite), adhesive (sodium silicate) and water. Test coupons produced by uniaxial pressing and burned to 1100 deg C they were submitted to physical and mechanical tests for determination the water absorption and flexion strength, respectively. The microstructure of ceramics produced was evaluated by diffraction of X-Ray, scanning electron microscopy and optical microscopy. After the production of the ceramic backing, welding tests were accomplished by the process MIG-MAG to evaluate the format of the weld bead. Based on the results obtained, during and after the welding accomplished with the employment of the ceramic backing, has shown that it is technically feasible for one-side welding. (author)

  1. Full Contoured Tooth-Implant Supported 3-Pointic All-Ceramic Denture During Occlusal Load Transfer in Lateral Region

    Directory of Open Access Journals (Sweden)

    Żmudzki J.

    2016-06-01

    Full Text Available Implant and a tooth supported dentures are avoided by dentists because of uneven distribution of occlusal loads between a stiffer implant and a more pliable tooth. The hypothesis was that a 3-point all-ceramic bridge supported on a natural second premolar tooth and a two-pieces typical implant bears safely mastication loads. The finite element analysis showed that the implant splinted by all-ceramic zirconium bridge with the second premolar was safe under lateral mastication load, but there was found an overload at wide zone of bone tissue around the implant under the load of 800 N. The patients can safely masticate, but comminution of hard food should be avoided and they should be instructed that after such an indiscretion they need to contact a dental professional, because, in spite of integrity of the prosthesis, the bone tissue around the implant may fail and there is a hazard of intrusion of the tooth.

  2. Support for the Armor Ceramics symposium at the 40th International Conference on Advanced Ceramics and Composites

    Science.gov (United States)

    2016-05-09

    WW-P069-2016. In situ HT -ESEM study of MO2 (M=Ce, Th, U) microspheres sintering: From neck elaboration to microstructure design G.I. Nkou Bouala...PERCENT_SUPPORTEDNAME FTE Equivalent: Total Number: Sub Contractors (DD882) Names of Faculty Supported Names of Under Graduate students supported Names of

  3. Retention of Employees in Ceramic Sanitary Ware Factories in India: Role of Work Life Balance, Career Development and Supervisor Support

    OpenAIRE

    S. Umamaheswari; Jayasree Krishnan

    2016-01-01

    The study examines the role of work life balance, career development and supervisor support on organization commitment over employees of unattended, ceramic sanitary ware factories in India. It also verifies the influence of organization commitment on retention and its mediating role. Findings reveal that organization commitment influences retention and all the above factors enhance it. Moreover, organization commitment partially mediates the relationship between proposed factors and retentio...

  4. Stress relaxation and creep of high-temperature gas-cooled reactor core support ceramic materials: a literature search

    International Nuclear Information System (INIS)

    Selle, J.E.; Tennery, V.J.

    1980-05-01

    Creep and stress relaxation in structural ceramics are important properties to the high-temperature design and safety analysis of the core support structure of the HTGR. The ability of the support structure to function for the lifetime of the reactor is directly related to the allowable creep strain and the ability of the structure to withstand thermal transients. The thermal-mechanical response of the core support pads to steady-state stresses and potential thermal transients depends on variables, including the ability of the ceramics to undergo some stress relaxation in relatively short times. Creep and stress relaxation phenomena in structural ceramics of interest were examined. Of the materials considered (fused silica, alumina, silicon nitride, and silicon carbide), alumina has been more extensively investigated in creep. Activation energies reported varied between 482 and 837 kJ/mole, and consequently, variations in the assigned mechanisms were noted. Nabarro-Herring creep is considered as the primary creep mechanism and no definite grain size dependence has been identified. Results for silicon nitride are in better agreement with reported activation energies. No creep data were found for fused silica or silicon carbide and no stress relaxation data were found for any of the candidate materials. While creep and stress relaxation are similar and it is theoretically possible to derive the value of one property when the other is known, no explicit demonstrated relationship exists between the two. For a given structural ceramic material, both properties must be experimentally determined to obtain the information necessary for use in high-temperature design and safety analyses

  5. A novel processing approach for free-standing porous non-oxide ceramic supports from polycarbosilane and polysilazane precursors.

    Science.gov (United States)

    Konegger, Thomas; Patidar, Rajesh; Bordia, Rajendra K

    2015-09-01

    In this contribution, a low-pressure/low-temperature casting technique for the preparation of novel free-standing macrocellular polymer-derived ceramic support structures is presented. Preceramic polymers (polycarbosilane and poly(vinyl)silazane) are combined with sacrificial porogens (ultra-high molecular weight polyethylene microbeads) to yield porous ceramic materials in the Si-C or Si-C-N systems, exhibiting well-defined pore structures after thermal conversion. The planar-disc-type specimens were found to exhibit biaxial flexural strengths of up to 60 MPa. In combination with their observed permeability characteristics, the prepared structures were found to be suitable for potential applications in filtration, catalysis, or membrane science.

  6. Fabrication of palladium nanoparticles immobilized on an amine-functionalized ceramic membrane support using a nanoparticulate colloidal impregnation method with enhanced catalytic properties

    Energy Technology Data Exchange (ETDEWEB)

    Du, Yan; Chen, Rizhi [Nanjing Tech University, Nanjing (China)

    2015-09-15

    An efficient and reusable catalyst was developed by depositing palladium nanoparticles on an amine-functionalized ceramic membrane support using a nanoparticulate colloidal impregnation method. The as-prepared Pdloaded ceramic membrane support was characterized by XRD, SEM, EDS, TEM, XPS, ICP, and its catalytic properties were investigated in the liquid-phase p-nitrophenol hydrogenation. A comparative study was also made with the palladium nanoparticles deposited on an amine-functionalized ceramic membrane support by an impregnation-reduction method. The palladium nanoparticles could be homogeneously immobilized on the ceramic membrane support surface, and exhibited excellent catalytic performance in the p-nitrophenol hydrogenation. The catalytic activity of the Pdloaded ceramic membrane support prepared by the nanoparticulate colloidal impregnation method increased by 16.6% compared to that of impregnation-reduction method. In the nanoparticulate colloidal impregnation method, palladium nanoparticles were presynthesized, higher loading of Pd(0) could be obtained, resulting in better catalytic activity. The as-prepared Pd-loaded ceramic membrane support could be easily reused for several cycles without appreciable degradation of catalytic activity.

  7. Novel Ceramic-Polymer Composite Membranes for the Separation of Hazardous Liquid Waste

    Energy Technology Data Exchange (ETDEWEB)

    Yoram Cohen

    2001-12-01

    The present project was conceived to address the need for robust yet selective membranes suitable for operating in harsh ph, solvent, and temperature environments. An important goal of the project was to develop a membrane chemical modification technology that would allow one to tailor-design membranes for targeted separation tasks. The method developed in the present study is based on the process of surface graft polymerization. Using essentially the same base technology of surface modification the research was aimed at demonstrating that improved membranes can be designed for both pervaporation separation and ultrafiltration. In the case of pervaporation, the present study was the first to demonstrate that pervaporation can be achieved with ceramic support membranes modified with an essentially molecular layer of terminally anchored polymer chains. The main advantage of the above approach, relative to other proposed membranes, is that the separating polymer layer is covalently attached to the ceramic support. Therefore, such membranes have a potential use in organic-organic separations where the polymer can swell significantly yet membrane robustness is maintained due to the chemical linkage of the chains to be inorganic support. The above membrane technology was also useful in developing fouling resistant ultrafiltration membranes. The prototype membrane developed in the project was evaluated for the treatment of oil-in-water microemulsions, demonstrating lack of irreversible fouling common with commercial membranes.

  8. A survey of structure characterization methods for ultrafiltration and reverse osmosis membranes

    NARCIS (Netherlands)

    Smolders, C.A.; Mulder, M.H.V.; van der Velden, P.M.

    1976-01-01

    Asymmetric membranes consist of a thin skin, which is permselective to certain molecules in solution, and a porous support, serving as a mechanical support layer and also as a transport layer for the permeate. Both in ultrafiltration and in hyperfiltration (reverse osmosis) asymmetric membranes are

  9. Effect of kaolin particle size and loading on the characteristics of kaolin ceramic support prepared via phase inversion technique

    Directory of Open Access Journals (Sweden)

    Siti Khadijah Hubadillah

    2016-06-01

    Full Text Available In this study, low cost ceramic supports were prepared from kaolin via phase inversion technique with two kaolin particle sizes, which are 0.04–0.6 μm (denoted as type A and 10–15 μm (denoted as type B, at different kaolin contents ranging from 14 to 39 wt.%, sintered at 1200 °C. The effect of kaolin particle sizes as well as kaolin contents on membrane structure, pore size distribution, porosity, mechanical strength, surface roughness and gas permeation of the support were investigated. The support was prepared using kaolin type A induced asymmetric structure by combining macroporous voids and sponge-like structure in the support with pore size of 0.38 μm and 1.05 μm, respectively, and exhibited ideal porosity (27.7%, great mechanical strength (98.9 MPa and excellent gas permeation. Preliminary study shows that the kaolin ceramic support in this work is potential to gas separation application at lower cost.

  10. SURVEY REGARDING THE ULTRAFILTRATION OF PROTEINES THROUGH MEMBRANE BASED PROCEDURES

    Directory of Open Access Journals (Sweden)

    CAMELIA HODOSAN

    2008-05-01

    Full Text Available This work is based on examples that emphasize the complexity of the proteins ultrafiltration process, pointing out the first 10-15 minutes of ultrafiltration. The knowledgement of the factors that influence the separation through ultrafiltration of proteins will allow to choose the right type of membrane, the frequent use of the same membrane and the operation in mechanical and chemical conditions adequate to the ultrafiltration system, when it is separated a protein with certain molecular weight.

  11. Ultrafiltration of hemicellulose hydrolysate fermentation broth

    Science.gov (United States)

    Kresnowati, M. T. A. P.; Desiriani, Ria; Wenten, I. G.

    2017-03-01

    Hemicelulosic material is often used as the main substrate to obtain high-value products such as xylose. The five carbon sugar, xylose, could be further processed by fermentation to produce xylitol. However, not only the hemicellulose hydrolysate fermentation broth contains xylitol, but also metabolite products, residual substances, biomass and mineral salts. Therefore, in order to obtain the end products, various separation processes are required to separate and purify the desired product from the fermentation broth. One of the most promising downstream processing methods of fermentation broth clarification is ultrafiltration due to its potential for energy saving and higher purity. In addition, ultrafiltration membrane has a high performance in separating inhibitory components in the fermentation broth. This paper assesses the influence of operating conditions; including trans-membrane pressure, velocity, pH of the fermentation broth solutions, and also to the xylitol concentration in the product. The challenges of the ultrafiltration process will be pointed out.

  12. An ultrafiltration assay for lysyl oxidase

    International Nuclear Information System (INIS)

    Shackleton, D.R.; Hulmes, D.J.

    1990-01-01

    A modification of the original microdistillation assay for lysyl oxidase is described in which Amicon C-10 microconcentrators are used to separate, by ultrafiltration, the 3H-labeled products released from a [4,5-3H]-lysine-labeled elastin substrate. Enzyme activity is determined by scintillation counting of the ultrafiltrate, after subtraction of radioactivity released in the presence of beta-aminopropionitrile, a specific inhibitor of the enzyme. Conditions are described which optimize both the sensitivity and the efficient use of substrate. The assay shows linear inhibition of activity in up to 1 M urea; hence, as the enzyme is normally diluted in the assay, samples in 6 M urea can be assayed directly, without prior dialysis, and corrected for partial inhibition. Comparable results are obtained when enzyme activity is assayed by ultrafiltration or microdistillation. The assay is simple and convenient and, by using disposable containers throughout, it eliminates the need for time-consuming decontamination of radioactive glassware

  13. Fine platinum nanoparticles supported on a porous ceramic membrane as efficient catalysts for the removal of benzene.

    Science.gov (United States)

    Liu, Hui; Li, Chengyin; Ren, Xiaoyong; Liu, Kaiqi; Yang, Jun

    2017-11-29

    It would be desirable to remove volatile organic compounds (VOCs) while we eliminate the dusts using silicon carbide (SiC)-based porous ceramics from the hot gases. Aiming at functionalizing SiC-based porous ceramics with catalytic capability, we herein report a facile strategy to integrate high efficient catalysts into the porous SiC substrates for the VOC removal. We demonstrate an aqueous salt method for uniformly distributing fine platinum (Pt) particles on the alumina (Al 2 O 3 ) layers, which are pre-coated on the SiC substrates as supports for VOC catalysts. We confirm that at a Pt mass loading as low as 0.176% and a weight hourly space velocity of 6000 mL g -1 h -1 , the as-prepared Pt/SiC@Al 2 O 3 catalysts can convert 90% benzene at a temperature of ca. 215 °C. The results suggest a promising way to design ceramics-based bi-functional materials for simultaneously eliminating dusts and harmful VOCs from various hot gases.

  14. 21 CFR 177.2910 - Ultra-filtration membranes.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ultra-filtration membranes. 177.2910 Section 177... Components of Articles Intended for Repeated Use § 177.2910 Ultra-filtration membranes. Ultra-filtration membranes identified in paragraphs (a)(1), (a)(2), (a)(3), and (a)(4) of this section may be safely used in...

  15. Development of ultrafiltration and inorganic adsorbents: January--March 1977

    International Nuclear Information System (INIS)

    Koenst, J.W. Jr.

    1977-01-01

    Ultrafiltration media with and without the assistance of bone char filters were evaluated to determine their effectiveness in removing radionuclides from contaminated solutions. Precipitants, resin, adsorbents, and inorganic adsorbents were studied to determine their effectiveness in decontaminating solutions. A study of the effects of radiation on ultrafiltration media was initiated. An ultrafiltration media pilot plant was ordered and is being installed

  16. Protein bioseparation using ultrafiltration: theory, applications and new developments

    National Research Council Canada - National Science Library

    Ghosh, Raja

    2003-01-01

    ... membrane-based separation process. This book discusses how ultrafiltration could be used for protein bioseparation. There are several good books on protein bioseparation and indeed several others on ultrafiltration. However, there are relatively fewer books dealing specifically with protein bioseparation using ultrafiltration, in spite of this being an a...

  17. Retention of Employees in Ceramic Sanitary Ware Factories in India: Role of Work Life Balance, Career Development and Supervisor Support

    Directory of Open Access Journals (Sweden)

    S. Umamaheswari

    2016-05-01

    Full Text Available The study examines the role of work life balance, career development and supervisor support on organization commitment over employees of unattended, ceramic sanitary ware factories in India. It also verifies the influence of organization commitment on retention and its mediating role. Findings reveal that organization commitment influences retention and all the above factors enhance it. Moreover, organization commitment partially mediates the relationship between proposed factors and retention. It also found that organization’s career development provision alone is not enough and need to be modified according to the employer’s expectation. Managerial implications and suggestions for future research were discussed.

  18. Evaluation of Ultrafiltration Performance for Phospholipid Separation

    Science.gov (United States)

    Aryanti, N.; Wardhani, D. H.; Maulana, Z. S.; Roberto, D.

    2017-11-01

    Ultrafiltration membrane for degumming of crude palm oil has been applied as an alternative method since the membrane process required less procedure than the conventional degumming. This research focused on the examination of ultrafiltration performance for phospholipid separation from model crude palm oil degumming. Specifically, profile flux and rejection, as well as blocking mechanism, were investigated. Feed consisting of Refined Crude Palm Oil - Isopropanol - Lecithin mixtures were represented as crude palm oil degumming. Lecithin was denoted a phospholipid component, and the concentrations of lecithin in feed were varied to 0.1%, 0.2%, and 0.3%. The concentration of phospholipid was determined as phosphor content. At the concentration of lecithin in feed representing phospholipid concentration of 8,45 mg/kg, 8,45 mg/kg, 24,87 mg/kg and 57,58 mg/kg, respectively. Flux profiles confirmed that there was a flux decline during filtration. In addition, the lecithin concentrations do not significantly effect on further flux decline. Rejection characteristic and phospholipid concentration in the permeate showed that the phospholipid rejections by ultrafiltration were in the range of 23-79,5% representing permeate’s phospholipid concentration of 1,73 - 44,25 mg/kg. Evaluation of fouling mechanism by Hermia’s blocking model confirmed that the standard blocking is the dominant mechanism in the ultrafiltration of lecithin mixture.

  19. Microfiltration and Ultrafiltration Membranes for Drinking Water

    Science.gov (United States)

    This article provides a concise and abbreviated summary of AWWA Manual of Practice M53, Microfiltration and Ultrafiltration Membranes for Drinking Water, to serve as a quick point of reference. For convenience, the article’s organization matches that of M53, as follows: • wate...

  20. Reexamining ultrafiltration and solute transport in groundwater

    Science.gov (United States)

    Neuzil, C. E.; Person, Mark

    2017-06-01

    Geologic ultrafiltration—slowing of solutes with respect to flowing groundwater—poses a conundrum: it is consistently observed experimentally in clay-rich lithologies, but has been difficult to identify in subsurface data. Resolving this could be important for clarifying clay and shale transport properties at large scales as well as interpreting solute and isotope patterns for applications ranging from nuclear waste repository siting to understanding fluid transport in tectonically active environments. Simulations of one-dimensional NaCl transport across ultrafiltering clay membrane strata constrained by emerging data on geologic membrane properties showed different ultrafiltration effects than have often been envisioned. In relatively high-permeability advection-dominated regimes, salinity increases occurred mostly within membrane units while their effluent salinity initially fell and then rose to match solute delivery. In relatively low-permeability diffusion-dominated regimes, salinity peaked at the membrane upstream boundary and effluent salinity remained low. In both scenarios, however, only modest salinity changes (up to ˜3 g L-1) occurred because of self-limiting tendencies; membrane efficiency declines as salinity rises, and although sediment compaction increases efficiency, it is also decreases permeability and allows diffusive transport to dominate. It appears difficult for ultrafiltration to generate brines as speculated, but widespread and less extreme ultrafiltration effects in the subsurface could be unrecognized. Conditions needed for ultrafiltration are present in settings that include topographically-driven flow systems, confined aquifer systems subjected to injection or withdrawal, compacting basins, and accretionary complexes.

  1. Characterization of clean and fouled ultrafiltration membranes

    NARCIS (Netherlands)

    Hanemaaijer, J.H.; Robbertsen, T.; van den Boomgaard, Anthonie; Olieman, C.; Both, P.; Schmidt, D.G.

    1988-01-01

    Much research into the fundamentals of membrane formation and separation has been performed in order to improve the efficiency of the manufacture of ultrafiltration membranes. Determination of the membrane characteristics is a key problem in these investigations. In this paper, we report on a study

  2. Removal of chromium from synthetic wastewater using MFI zeolite membrane supported on inexpensive tubular ceramic substrate

    Directory of Open Access Journals (Sweden)

    R. Vinoth Kumar

    2017-09-01

    Full Text Available A mordenite framework inverted (MFI type zeolite membrane was produced on inexpensive tubular ceramic substrate through hydrothermal synthesis and applied for the removal of chromium from synthetic wastewater. The fabricated ceramic substrate and membrane was characterized by diverse standard techniques such as X-ray diffraction, field emission scanning electron microscope, porosity, water permeability and pore size measurements. The porosity of the ceramic substrate (53% was reduced by the deposition of MFI (51% zeolite layer. The pore size and water permeability of the membrane was evaluated as 0.272 μm and 4.43 × 10–7 m3/m2s.kPa, respectively, which are lower than that of the substrate pore size (0.309 μm and water permeability (5.93 × 10–7 m3/m2s.kPa values. To identify the effectiveness of the prepared membrane, the applied pressure of the filtration process and initial chromium concentration and cross flow rate were varied to study their influence on the permeate flux and percentage of removal. The maximum removal of chromium achieved was 78% under an applied pressure of 345 kPa and an initial feed concentration of 1,000 ppm. Finally, the efficiency of the membrane for chromium removal was assessed with other membranes reported in the literature.

  3. Synthesis of inorganic materials in a supercritical carbon dioxide medium. Application to ceramic cross-flow filtration membranes preparation

    International Nuclear Information System (INIS)

    Papet, Sebastien

    2000-01-01

    Membrane separations, using cross-flow mineral ceramic membranes, allows fractionation of aqueous solutions due to the molecular sieve effect and electrostatic charges. To obtain a high selectivity, preparation of new selective ceramic membranes is necessary. We propose in this document two different routes to prepare such cross-flow tubular mineral membranes. In the first exposed method, a ceramic material is used, titanium dioxide, synthesized in supercritical carbon dioxide by the hydrolysis of an organometallic precursor of the oxide. The influence of operating parameters is similar to what is observed during a liquid-phase synthesis (sol-gel process), and leads us to control the size and texture of the prepared particles. This material is then used to prepare mineral membrane with a compressed layer process. The particles are mixed with organic components to form a liquid suspension. A layer is then deposited on the internal surface of a tubular porous support by slip-casting. The layer is then dried and compressed on the support before sintering. The obtained membranes arc in the ultrafiltration range. A second process has been developed in this work. It consists on the hydrolysis, in a supercritical CO 2 medium, of a precursor of titanium dioxide infiltrated into the support. The obtained material is then both deposited on the support but also infiltrated into the porosity. This new method leads to obtain ultrafiltration membranes that retain molecules which molecular weight is round 4000 g.mol -1 . Furthermore, we studied mass transfer mechanisms in cross-flow filtration of aqueous solutions. An electrostatic model, based on generalized Nernst-Planck equation that takes into account electrostatic interactions between solutes and the ceramic material, lead us to obtain a good correlation between experimental results and the numerical simulation. (author) [fr

  4. Cross flow microfiltration of oil-water emulsions using clay based ceramic membrane support and TiO2 composite membrane

    OpenAIRE

    Kanchapogu Suresh; G. Pugazhenthi

    2017-01-01

    The main objective of this work is to study the effect of cross flow filtration conditions on the separation of oily wastewater using ceramic support and TiO2 membrane. Firstly, the low cost clay based ceramic membrane support was prepared by uniaxial compaction method using combination of pyrophyllite, quartz, feldspar, kaolin, ball clay and calcium carbonate along with PVA as a binder. Subsequently, TiO2 composite membrane was fabricated via hydrothermal route employing TiO2 sol derived fro...

  5. Sequential micro and ultrafiltration of distillery wastewater

    Directory of Open Access Journals (Sweden)

    Vasić Vesna M.

    2015-01-01

    Full Text Available Water reuse and recycling, wastewater treatment, drinking water production and environmental protection are the key challenges for the future of our planet. Membrane separation technologies for the removal of all suspended solids and a fraction of dissolved solids from wastewaters, are becoming more and more promising. Also, these processes are playing a major role in wastewater purification systems because of their high potential for recovery of water from many industrial wastewaters. The aim of this work was to evaluate the application of micro and ultrafiltration for distillery wastewater purification in order to produce water suitable for reuse in the bioethanol industry. The results of the analyses of the permeate obtained after micro and ultrafiltration showed that the content of pollutants in distillery wastewater was significantly reduced. The removal efficiency for chemical oxygen demand, dry matter and total nitrogen was 90%, 99.2% and 99.9%, respectively. Suspended solids were completely removed from the stillage.

  6. Environment-oriented low-cost porous mullite ceramic membrane supports fabricated from coal gangue and bauxite

    Energy Technology Data Exchange (ETDEWEB)

    Lü, Qikai [Institute of Urban Environment, Chinese Academy of Sciences, Xiamen (China); Ningbo Urban Environment Observation and Research Station-NUEORS, Chinese Academy of Sciences, Ningbo (China); School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou (China); Dong, Xinfa [School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou (China); Zhu, Zhiwen [Institute of Urban Environment, Chinese Academy of Sciences, Xiamen (China); Ningbo Urban Environment Observation and Research Station-NUEORS, Chinese Academy of Sciences, Ningbo (China); Dong, Yingchao, E-mail: ycdong@iue.ac.cn [Institute of Urban Environment, Chinese Academy of Sciences, Xiamen (China); Ningbo Urban Environment Observation and Research Station-NUEORS, Chinese Academy of Sciences, Ningbo (China)

    2014-05-01

    Highlights: • Coal gangue was recycled to fabricate low-cost porous mullite membrane supports. • A unique volume-expansion occurred due to a mullitization-crystal-growth process. • A porous structure consists of glassy particles and embedded mullite crystals. - Abstract: Porous mullite ceramic supports for filtration membrane were successfully fabricated via recycling of coal gangue and bauxite at sintering temperatures from 1100 to 1500 °C with corn starch as pore-forming agent. The dynamic sintering behaviors, phase evolution, shrinkage, porosity and pore size, gas permeation flux, microstructure and mechanical property were systematically studied. A unique volume-expansion stage was observed at increased temperatures from 1276 to 1481 °C caused by a mullitization-crystal-growth process. During this stage, open porosity increases and pore size distributions broaden, which result in a maximum of nitrogen gas flux at 1400 °C. The X-ray diffraction results reveal that secondary mullitization took place from 1100 °C and the major phase is mullite with a content of ∼84.7 wt.% at 1400 °C. SEM images show that the as-fabricated mullite supports have a porous microstructure composed of sintered glassy particles embedded with inter-locked mullite crystals, which grew gradually with increasing temperature from rod-like into blocky-like morphologies. To obtain mullite membrane supports with sufficient porosity and acceptable mechanical strength, the relationship between porosity and mechanical strength was investigated, which was fitted using a parabolic equation.

  7. Incorporation of zinc for fabrication of low-cost spinel-based composite ceramic membrane support to achieve its stabilization.

    Science.gov (United States)

    Li, Lingling; Dong, Xinfa; Dong, Yingchao; Zhu, Li; You, Sheng-Jie; Wang, Ya-Fen

    2015-04-28

    In order to reduce environment risk of zinc, a spinel-based porous membrane support was prepared by the high-temperature reaction of zinc and bauxite mineral. The phase evolution process, shrinkage, porosity, mechanical property, pore size distribution, gas permeation flux and microstructure were systematically studied. The XRD results, based on a Zn/Al stoichiometric composition of 1/2, show a formation of ZnAl2O4 structure starting from 1000°C and then accomplished at 1300°C. For spinel-based composite membrane, shrinkage and porosity are mainly influenced by a combination of an expansion induced by ZnAl2O4 formation and a general densification due to amorphous liquid SiO2. The highest porosity, as high as 44%, is observed in ZnAl4 membrane support among all the investigated compositions. Compared with pure bauxite (Al), ZnAl4 composite membrane support is reinforced by ZnAl2O4 phase and inter-locked mullite crystals, which is proved by the empirical strength-porosity relationships. Also, an increase in average pore diameter and gas flux can be observed in ZnAl4. A prolonged leaching experiment reveals the zinc can be successfully incorporated into ceramic membrane support via formation of ZnAl2O4, which has substantially better resistance toward acidic attack. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Cross flow microfiltration of oil-water emulsions using clay based ceramic membrane support and TiO2 composite membrane

    Directory of Open Access Journals (Sweden)

    Kanchapogu Suresh

    2017-09-01

    Full Text Available The main objective of this work is to study the effect of cross flow filtration conditions on the separation of oily wastewater using ceramic support and TiO2 membrane. Firstly, the low cost clay based ceramic membrane support was prepared by uniaxial compaction method using combination of pyrophyllite, quartz, feldspar, kaolin, ball clay and calcium carbonate along with PVA as a binder. Subsequently, TiO2 composite membrane was fabricated via hydrothermal route employing TiO2 sol derived from TiCl4 and NH4OH solution. Cross flow microfiltration investigations were carried out by utilizing oil-water emulsion concentration of 200 mg/L at three distinct applied pressures (69–207 kPa and three cross flow velocities (0.0885, 0.1327, and 0.1769 m/s. Compared to ceramic support, TiO2 composite membrane demonstrates better performance in terms of flux and removal efficiency of oil and also the rate of flux decline during filtration operation is lower due to highly hydrophilic surface of the TiO2 membrane. TiO2 membrane displays the oil removal efficiency of 99% in the entire range of applied pressures investigation, while ceramic support shows 93–96% of oil removal.

  9. Environment-oriented low-cost porous mullite ceramic membrane supports fabricated from coal gangue and bauxite.

    Science.gov (United States)

    Lü, Qikai; Dong, Xinfa; Zhu, Zhiwen; Dong, Yingchao

    2014-05-30

    Porous mullite ceramic supports for filtration membrane were successfully fabricated via recycling of coal gangue and bauxite at sintering temperatures from 1100 to 1500°C with corn starch as pore-forming agent. The dynamic sintering behaviors, phase evolution, shrinkage, porosity and pore size, gas permeation flux, microstructure and mechanical property were systematically studied. A unique volume-expansion stage was observed at increased temperatures from 1276 to 1481°C caused by a mullitization-crystal-growth process. During this stage, open porosity increases and pore size distributions broaden, which result in a maximum of nitrogen gas flux at 1400°C. The X-ray diffraction results reveal that secondary mullitization took place from 1100°C and the major phase is mullite with a content of ∼84.7wt.% at 1400°C. SEM images show that the as-fabricated mullite supports have a porous microstructure composed of sintered glassy particles embedded with inter-locked mullite crystals, which grew gradually with increasing temperature from rod-like into blocky-like morphologies. To obtain mullite membrane supports with sufficient porosity and acceptable mechanical strength, the relationship between porosity and mechanical strength was investigated, which was fitted using a parabolic equation. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Portfolio: Ceramics.

    Science.gov (United States)

    Hardy, Jane; And Others

    1982-01-01

    Describes eight art activities using ceramics. Elementary students created ceramic tiles to depict ancient Egyptian and medieval European art, made ceramic cookie stamps, traced bisque plates on sketch paper, constructed clay room-tableaus, and designed clay relief masks. Secondary students pit-fired ceramic pots and designed ceramic Victorian…

  11. Ultrafiltrative deinking of flexographic ONP : the role of surfactants

    Science.gov (United States)

    Bradley H. Upton; Gopal A. Krishnagopalan; Said Abubakr

    1999-01-01

    Ultrafiltration is a potentially viable method of removing finely dispersed flexographic pigments from the deinking water loop. This work examines the effects of surface-active materials on ultrafiltration efficiency. A logarithmic relationship between permeate flax and pigment concentration was demonstrated at ink concentrations above 0.4%, permeation rates becoming...

  12. [Influence of coping material selection and porcelain firing on marginal and internal fit of computer-aided design/computer- aided manufacturing of zirconia and titanium ceramic implant-supported crowns].

    Science.gov (United States)

    Cuiling, Liu; Liyuan, Yang; Xu, Gao; Hong, Shang

    2016-06-01

    This study aimed to investigate the influence of coping material and porcelain firing on the marginal and internal fit of computer-aided design/computer-aided manufacturing (CAD/CAM) of zirconia ceramic implant- and titanium ceramic implant-supported crowns. Zirconia ceramic implant (group A, n = 8) and titanium metal ceramic implant-supported crowns (group B, n = 8) were produced from copings using the CAD/CAM system. The marginal and internal gaps of the copings and crowns were measured by using a light-body silicone replica technique combined with micro-computed tomography scanning to obtain a three-dimensional image. Marginal gap (MG), horizontal marginal discrepancy (HMD), and axial wall (AW) were measured. Statistical analyses were performed using SPSS 17.0. Prior to porcelain firing, the measurements for MG, HMD, and AW of copings in group A were significantly larger than those in group B (P 0.05). Porcelain firing significantly reduced MG (P 0.05). The marginal fits of CAD/CAM zirconia ceramic implant-supported crowns were superior to those of CAD/CAM titanium ceramic-supported crowns. The fits of both the CAD/CAM zirconia ceramic implant- and titanium ceramic implant-supported crowns were obviously influenced by porcelain firing.

  13. Development of a Novel Ceramic Support Layer for Planar Solid Oxide Cells

    DEFF Research Database (Denmark)

    Klemensø, Trine; Boccaccini, Dino; Brodersen, Karen

    2014-01-01

    The conventional solid oxide cell is based on a Ni–YSZ support layer, placed on the fuel side of the cell, also known as the anode supported SOFC. An alternative design, based on a support of porous 3YSZ (3 mol.% Y2O3–doped ZrO2), placed on the oxygen electrode side of the cell, is proposed...... of the support can be done simultaneously with forming the oxygen electrode, since some of the best performing oxygen electrodes are based on infiltrated LSC. The potential of the proposed structure was investigated by testing the mechanical and electrical properties of the support layer. Comparable strength...... properties to the conventional Ni/YSZ support were seen, and sufficient and fairly stable conductivity of LSC infiltrated 3YSZ was observed. The conductivity of 8–15 S cm–1 at 850 °C seen for over 600 h, corresponds to a serial resistance of less than 3.5 m Ω cm2 of a 300 μm thick support layer....

  14. Design and optimization of porous ceramic supports for asymmetric ceria-based oxygen transport membranes

    DEFF Research Database (Denmark)

    Kaiser, Andreas; Foghmoes, Søren Preben Vagn; Pećanac, G.

    2016-01-01

    The microstructure, mechanical properties and gas permeability of porous supports of Ce0.9Gd0.1O1.95−δ (CGO) were investigated as a function of sintering temperature and volume fraction of pore former for use in planar asymmetric oxygen transport membranes (OTMs). With increasing the pore former...... content from 11 vol% to 16 vol%, the gas permeabilities increased by a factor of 5 when support tapes were sintered to comparable densities. The improved permeabilities were due to a more favourable microstructure with larger interconnected pores at a porosity of 45% and a fracture strength of 47±2 MPa (m...

  15. Evaluation of marginal fit of single implant-supported metal-ceramic crowns prepared by using presintered metal blocks.

    Science.gov (United States)

    Pasali, Baris; Sarac, Duygu; Kaleli, Necati; Sarac, Yakup Sinasi

    2018-02-01

    Recently, presintered metal blocks for nonprecious and precious metal implant-supported restorations have gained popularity in computer-aided design and computer-aided manufacturing (CAD-CAM) systems. However, few studies have evaluated the marginal discrepancy of implant-supported restorations made with these new alloy systems. The purpose of this in vitro study was to compare the milling-sintering method with the lost-wax and milling methods in terms of the marginal fit of implant-supported metal-ceramic restorations. Thirty implant abutments screwed to implant analogs were embedded into acrylic resin to investigate marginal fit and then divided according to fabrication methods into the following 3 groups (n=10): lost-wax (LW; control group), milling (M), and milling-sintering (MS). Porcelain material was applied to all specimens after completion of the fabrication process. Subsequently, all specimens were cemented to implant abutments for the measurement of marginal discrepancies. Twelve marginal discrepancy measurements were recorded on each implant abutment by using a stereomicroscope. The arithmetic mean of these 12 measurements was considered the mean marginal discrepancy value of each abutment. Data were statistically analyzed by using 1-way ANOVA and Tukey honest significant difference tests (α=.05). The lowest mean marginal discrepancy values (81 ±2 μm) were observed in the M group, which was significantly different (Pmarginal discrepancy values (99 ±2 μm) were observed in the MS group. The results revealed that restorations prepared by the milling-sintering method provided clinically acceptable results (marginal fit. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  16. Stress analysis and fail-safe design of bilayered tubular supported ceramic membranes

    DEFF Research Database (Denmark)

    Kwok, Kawai; Frandsen, Henrik Lund; Søgaard, Martin

    2014-01-01

    . Stress distributions in two membrane systems have been analyzed and routes to minimize stress are proposed. For a Ba0.5Sr0.5Co0.8Fe0.2O3−δBa0.5Sr0.5Co0.8Fe0.2O3−δ membrane supported on a porous substrate of the same material under pressure-vacuum operation, the optimal configuration in terms...... for both membrane systems at operating conditions in the range of practical interest....

  17. Deposition of thin ultrafiltration membranes on commercial SiC microfiltration tubes

    DEFF Research Database (Denmark)

    Facciotti, Marco; Boffa, Vittorio; Magnacca, Giuliana

    2014-01-01

    Porous SiC based materials present high mechanical, chemical and thermal robustness, and thus have been largely applied to water-filtration technologies. In this study, commercial SiC microfiltration tubes with nominal pore size of 0.04 m were used as carrier for depositing thin aluminium oxide....... After 5 times coating, a 5.6 µm thick γ-Al2O3 layer was obtained. This membrane shows retention of ~75% for polyethylene glycol molecules with Mn of 8 and 35 kDa, indicating that, despite their intrinsic surface roughness, commercial SiC microfiltration tubes can be applied as carrier for thin...... ultrafiltration membranes. This work also indicates that an improvement of the commercial SiC support surface smoothness may greatly enhance permeance and selectivity of Υ-Al2O3 ultrafiltration membranes by allowing the deposition of thinner defect-free layers....

  18. Influence of Abutment Design on Stiffness, Strength, and Failure of Implant-Supported Monolithic Resin Nano Ceramic (RNC) Crowns.

    Science.gov (United States)

    Joda, Tim; Huber, Samuel; Bürki, Alexander; Zysset, Philippe; Brägger, Urs

    2015-12-01

    Recent technical development allows the digital manufacturing of monolithic reconstructions with high-performance materials. For implant-supported crowns, the fixation requires an abutment design onto which the reconstruction can be bonded. The aim of this laboratory investigation was to analyze stiffness, strength, and failure modes of implant-supported, computer-assisted design and computer-aided manufacturing (CAD/CAM)-generated resin nano ceramic (RNC) crowns bonded to three different titanium abutments. Eighteen monolithic RNC crowns were produced and loaded in a universal testing machine under quasi-static condition according to DIN ISO 14801. With regard to the type of titanium abutment, three groups were defined: (1) prefabricated cementable standard; (2) CAD/CAM-constructed individualized; and (3) novel prefabricated bonding base. Stiffness and strength were measured and analyzed statistically with Wilcoxon rank sum test. Sections of the specimens were examined microscopically. Stiffness demonstrated high stability for all specimens loaded in the physiological loading range with means and standard deviations of 1,579 ± 120 N/mm (group A), 1,733 ± 89 N/mm (group B), and 1,704 ± 162 N/mm (group C). Mean strength of the novel prefabricated bonding base (group C) was 17% lower than of the two other groups. Plastic deformations were detectable for all implant-abutment crown connections. Monolithic implant crowns made of RNC seem to represent a feasible and stable prosthetic construction under laboratory testing conditions with strength higher than the average occlusal force, independent of the different abutment designs used in this investigation. © 2014 Wiley Periodicals, Inc.

  19. Ultrafiltration by gyroid nanoporous polymer membranes

    DEFF Research Database (Denmark)

    Li, Li; Szewczykowski, Piotr Przemyslaw; Clausen, Lydia D.

    2011-01-01

    the effect of membrane fouling on the flux decline and rejection profiles. Significant fouling occurred in the case of hydrophobic membranes in contact with water solutions, while in the presence of high concentration of ethanol in the filtration solution and in the case of hydrophilized membranes...... the fouling was reduced. The observed rejection of PEG was compared with theoretic predictions, as described by the Bungay–Brenner model. The model satisfactorily described the rejection profile of PEG up to 12kg/mol through hydrophobic membranes in the presence of excess ethanol. A significantly reduced......Gyroid nanoporous cross-linked 1,2-polybutadiene membranes with uniform pores were developed for ultrafiltration applications. The gyroid porosity has the advantage of isotropic percolation with no need for structure pre-alignment. The effects of solvent and surface photo...

  20. Adsorption of amylase enzyme on ultrafiltration membranes

    DEFF Research Database (Denmark)

    Beier, Søren; Enevoldsen, Ann Dorrit; Kontogeorgis, Georgios

    2007-01-01

    A method to measure the static adsorption on membrane surfaces has been developed and described. The static adsorption of an amylase-F has been measured on two different ultrafiltration membranes, both with a cut-off value of 10 kDa (a PES membrane and the ETNA10PP membrane, which is a surface......-modified PVDF membrane). The adsorption follows the Langmuir adsorption theory. Thus, the static adsorption consists of monolayer coverage. The static adsorption is expressed both as a permeability drop and an adsorption resistance. From the adsorption isotherms the maximum static permeability drops...... and the maximum static adsorption resistances are determined. The maximum static permeability drop for the hydrophobic PES membrane is 75 % and the maximum static adsorption resistance is 0.014 m2hbar/L. The maximum static permeability drop for the hydrophilic surface-modified PVDF membrane (ETNA10PP) is 23...

  1. Separation of BSA through FAU-type zeolite ceramic composite membrane formed on tubular ceramic support: Optimization of process parameters by hybrid response surface methodology and biobjective genetic algorithm.

    Science.gov (United States)

    Vinoth Kumar, R; Ganesh Moorthy, I; Pugazhenthi, G

    2017-08-09

    In this study, Faujasite (FAU) zeolite was coated on low-cost tubular ceramic support as a separating layer through hydrothermal route. The mixture of silicate and aluminate solutions was used to create a zeolitic separation layer on the support. The prepared zeolite ceramic composite membrane was characterized using X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), particle size distribution (PSD), field emission scanning electron microscopy (FESEM), and zeta potential measurements. The porosity of ceramic support (53%) was reduced by the deposition of FAU (43%) zeolite layer. The pore size and water permeability of the membrane were evaluated as 0.179 µm and 1.62 × 10 -7  m 3 /m 2  s kPa, respectively, which are lower than that of the support (pore size of 0.309 µm and water permeability of 5.93 × 10 -7  m 3 /m 2  s kPa). The permeate flux and rejection potential of the prepared membrane were evaluated by microfiltration of bovine serum albumin (BSA). To study the influences of three independent variables such as operating pressure (68.94-275.79 kPa), concentration of BSA (100-500 ppm), and solution pH (2-4) on permeate flux and percentage of rejection, the response surface methodology (RSM) was used. The predicted models for permeate flux and rejection were further subjected to biobjective genetic algorithm (GA). The hybrid RSM-GA approach resulted in a maximum permeate flux of 2.66 × 10 -5  m 3 /m 2  s and BSA rejection of 88.02%, at which the optimum conditions were attained as 100 ppm BSA concentration, 2 pH solution, and 275.79 kPa applied pressure. In addition, the separation efficiency was compared with other membranes applied for BSA separation to know the potential of the fabricated FAU zeolite ceramic composite membrane.

  2. Fatigue Fracture Strength of Implant-Supported Full Contour Zirconia and Metal Ceramic Fixed Partial Dentures

    Directory of Open Access Journals (Sweden)

    Fariborz Vafaee

    2017-10-01

    Full Text Available Objectives: Zirconia restorations have been suggested as a more durable and more appealing alternative to metal restorations. However, their mechanical properties may be negatively affected by fatigue due to superficial stresses or low temperature degradation. This study aimed to assess the fatigue fracture strength of three-unit implant-supported full contour zirconia and pre-sintered cobalt-chromium (Co-Cr alloy posterior fixed partial dentures (FPDs.Materials and Methods: In this in-vitro experimental study, 28 posterior three-unit implant-supported FPDs were fabricated of full contour zirconia and pre-sintered Co-Cr alloy, and were cemented on implant abutments. To simulate the oral environment, FPDs were subjected to 10,000 thermal cycles between 5-55°C for 30 seconds, and were then transferred to a chewing simulator (100,000 cycles, 50 N, 0.5 Hz. Afterwards, fatigue fracture strength was measured using a universal testing machine. Data were analyzed by Mann-Whitney U test.Results: The mean and standard deviation of fracture strength were 2108.6±440.1 N in full contour zirconia, and 3499.9±1106.5 N in pre-sintered Co-Cr alloy. According to Mann- Whitney U test, the difference in this respect was statistically significant between the two groups (P=0.007.Conclusions: Since the fracture strength values obtained in the two groups were significantly higher than the maximum mean masticatory load in the oral environment, both materials can be used for fabrication of posterior three-unit FPDs, depending on the esthetic demands of patients.

  3. Deposition of Pd–Ag thin film membranes on ceramic supports for hydrogen purification/separation

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, A.I. [Centre of Physics, University of Minho, Campus Azurém, 4800-058 (Portugal); Pérez, P.; Rodrigues, S.C.; Mendes, A.; Madeira, L.M. [LEPAE, Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias s/n, 4200-465 Porto (Portugal); Tavares, C.J., E-mail: ctavares@fisica.uminho.pt [Centre of Physics, University of Minho, Campus Azurém, 4800-058 (Portugal)

    2015-01-15

    Highlights: • Thin film Pd–Ag membranes have been produced for hydrogen selectivity. • Magnetron sputtering yields Pd–Ag compact films for atomic H diffusion. • The thin film Pd–Ag membranes yielded a selectivity of α (H{sub 2}/N{sub 2}) = 10. - Abstract: Pd–Ag based membranes supported on porous α-Al{sub 2}O{sub 3} (doped with yttria-stabilized zirconia) were studied for hydrogen selective separation. Magnetron sputtering technique was employed for the synthesis of thin film membranes. The hydrogen permeation flux is affected by the membrane columnar structure, which is formed during deposition. From scanning electron microscopy analysis, it was observed that different sputtering deposition pressures lead to distinct columnar structure growth. X-ray diffraction patterns provided evidence of a Pd–Ag solid solution with an average crystallite domain size of 21 nm, whose preferential growth can be altered by the deposition pressure. The gas-permeation results have shown that the Pd–Ag membrane supported on porous α-Al{sub 2}O{sub 3} is selective toward H{sub 2}. For optimized membrane synthesis conditions, the permeance toward N{sub 2} is 0.076 × 10{sup −6} mol m{sup −2} s{sup −1} Pa{sup −1} at room temperature, whereas for a pressure difference of 300 kPa the H{sub 2}-flux is of the order of ca. 0.21 mol m{sup −2} s{sup −1}, which corresponds to a permeance of 0.71 × 10{sup −6} mol m{sup −2} s{sup −1} Pa{sup −1}, yielding a selectivity of α (H{sub 2}/N{sub 2}) = 10. These findings suggest that the membrane has a reasonable capacity to selectively permeate this gas.

  4. Low fouling polysulfone ultrafiltration membrane via click chemistry

    KAUST Repository

    Xie, Yihui; Tayouo Djinsu, Russell; Nunes, Suzana Pereira

    2014-01-01

    %, and 94%). The glass transition temperature shifted with the introduction of triazole pendant groups from 190°C (unmodified) to 171°C. Ultrafiltration membranes were prepared via phase inversion by immersion in different coagulation baths (NMP

  5. Ceramic Technology Project

    Energy Technology Data Exchange (ETDEWEB)

    1992-03-01

    The Ceramic Technology Project was developed by the USDOE Office of Transportation Systems (OTS) in Conservation and Renewable Energy. This project, part of the OTS's Materials Development Program, was developed to meet the ceramic technology requirements of the OTS's automotive technology programs. Significant accomplishments in fabricating ceramic components for the USDOE and NASA advanced heat engine programs have provided evidence that the operation of ceramic parts in high-temperature engine environments is feasible. These programs have also demonstrated that additional research is needed in materials and processing development, design methodology, and data base and life prediction before industry will have a sufficient technology base from which to produce reliable cost-effective ceramic engine components commercially. A five-year project plan was developed with extensive input from private industry. In July 1990 the original plan was updated through the estimated completion of development in 1993. The objective is to develop the industrial technology base required for reliable ceramics for application in advanced automotive heat engines. The project approach includes determining the mechanisms controlling reliability, improving processes for fabricating existing ceramics, developing new materials with increased reliability, and testing these materials in simulated engine environments to confirm reliability. Although this is a generic materials project, the focus is on the structural ceramics for advanced gas turbine and diesel engines, ceramic bearings and attachments, and ceramic coatings for thermal barrier and wear applications in these engines. To facilitate the rapid transfer of this technology to US industry, the major portion of the work is being done in the ceramic industry, with technological support from government laboratories, other industrial laboratories, and universities.

  6. Mounting for ceramic scroll

    Science.gov (United States)

    Petty, Jack D.

    1993-01-01

    A mounting for a ceramic scroll on a metal engine block of a gas turbine engine includes a first ceramic ring and a pair of cross key connections between the first ceramic ring, the ceramic scroll, and the engine block. The cross key connections support the scroll on the engine block independent of relative radial thermal growth and for bodily movement toward an annular mounting shoulder on the engine. The scroll has an uninterrupted annular shoulder facing the mounting shoulder on the engine block. A second ceramic ring is captured between mounting shoulder and the uninterrupted shoulder on the scroll when the latter is bodily shifted toward the mouting shoulder to define a gas seal between the scroll and the engine block.

  7. Treatment of the Bleaching Effluent from Sulfite Pulp Production by Ceramic Membrane Filtration

    OpenAIRE

    Ebrahimi, Mehrdad; Busse, Nadine; Kerker, Steffen; Schmitz, Oliver; Hilpert, Markus; Czermak, Peter

    2015-01-01

    Pulp and paper waste water is one of the major sources of industrial water pollution. This study tested the suitability of ceramic tubular membrane technology as an alternative to conventional waste water treatment in the pulp and paper industry. In this context, in series batch and semi-batch membrane processes comprising microfiltration, ultrafiltration and nanofiltration, ceramic membranes were developed to reduce the chemical oxygen demand (COD) and remove residual lignin from the effluen...

  8. Cake layers and long filtration times protect ceramic micro-filtration membranes for fouling

    NARCIS (Netherlands)

    Lu, J.

    2013-01-01

    The objective of this research was to decrease membrane fouling of a ceramic microfiltration system and at the same time increase the recovery. A conventional operation in micro- and ultrafiltration is an in-line coagulation and a frequent hydraulic backwash. The idea about these frequent backwashes

  9. Concentration of lemon pectin extract by ultrafiltration

    Directory of Open Access Journals (Sweden)

    Damián Stechina

    2012-09-01

    Full Text Available Current annual lemon production in Argentina is about 900 thousand t. 75% is used industrially to obtain pasteurized juice concentrate. Since 40 - 45 % of citrus fruit content is peel and seeds, the annual lemon residue yield is 360 thousand t. Lemon peel contains about 30% (B.S. of peptic substances with an important commercial value due to its gelling and thickening properties for food, chemical, pharmacological and cosmetic products. Membrane processes have many applications in food manufacture. The objective of this study is to analyze the influence of ultrafiltration operating variables on instant permeate flow (Fp and on the energy requirement for pectin extract concentration from lemon peel. A DDS lab module was used, lab 20-772 model with synthetic material membranes, 9 kDa, shear force, the intrinsic membrane resistance (Rm being 3*1013 m -1 . Results show that Fp decrease caused by polarization induced resistance occurrence and the influence of operating variables on Fp offer relevant data to estimate the energy requirement in relation to feeding flow at constant temperature, which may be compared to pectin concentration increase in the retained flow in relation to initial extract concentration.

  10. Ceramic hot-gas filter

    Science.gov (United States)

    Connolly, E.S.; Forsythe, G.D.; Domanski, D.M.; Chambers, J.A.; Rajendran, G.P.

    1999-05-11

    A ceramic hot-gas candle filter is described having a porous support of filament-wound oxide ceramic yarn at least partially surrounded by a porous refractory oxide ceramic matrix, and a membrane layer on at least one surface thereof. The membrane layer may be on the outer surface, the inner surface, or both the outer and inner surface of the porous support. The membrane layer may be formed of an ordered arrangement of circularly wound, continuous filament oxide ceramic yarn, a ceramic filler material which is less permeable than the filament-wound support structure, or some combination of continuous filament and filler material. A particularly effective membrane layer features circularly wound filament with gaps intentionally placed between adjacent windings, and a filler material of ceramic particulates uniformly distributed throughout the gap region. The filter can withstand thermal cycling during back pulse cleaning and is resistant to chemical degradation at high temperatures.

  11. Ceramic hot-gas filter

    Science.gov (United States)

    Connolly, Elizabeth Sokolinski; Forsythe, George Daniel; Domanski, Daniel Matthew; Chambers, Jeffrey Allen; Rajendran, Govindasamy Paramasivam

    1999-01-01

    A ceramic hot-gas candle filter having a porous support of filament-wound oxide ceramic yarn at least partially surrounded by a porous refractory oxide ceramic matrix, and a membrane layer on at least one surface thereof. The membrane layer may be on the outer surface, the inner surface, or both the outer and inner surface of the porous support. The membrane layer may be formed of an ordered arrangement of circularly wound, continuous filament oxide ceramic yarn, a ceramic filler material which is less permeable than the filament-wound support structure, or some combination of continuous filament and filler material. A particularly effective membrane layer features circularly wound filament with gaps intentionally placed between adjacent windings, and a filler material of ceramic particulates uniformly distributed throughout the gap region. The filter can withstand thermal cycling during backpulse cleaning and is resistant to chemical degradation at high temperatures.

  12. Advanced Ceramics

    International Nuclear Information System (INIS)

    1989-01-01

    The First Florida-Brazil Seminar on Materials and the Second State Meeting about new materials in Rio de Janeiro State show the specific technical contribution in advanced ceramic sector. The others main topics discussed for the development of the country are the advanced ceramic programs the market, the national technic-scientific capacitation, the advanced ceramic patents, etc. (C.G.C.) [pt

  13. High throughput measurement of high temperature strength of ceramics in controlled atmosphere and its use on solid oxide fuel cell anode supports

    DEFF Research Database (Denmark)

    Frandsen, Henrik Lund; Curran, Declan; Rasmussen, Steffen

    2014-01-01

    In the development of structural and functional ceramics for high temperature electrochemical conversion devices such as solid oxide fuel cells, their mechanical properties must be tested at operational conditions, i.e. at high temperature and controlled atmospheres. Furthermore, characterization...... for testing multiple samples at operational conditions providing a high throughput and thus the possibility achieve high reliability. Optical methods are used to measure deformations contactless, frictionless load measuring is achieved, and multiple samples are handled in one heat up. The methodology...... is validated at room temperature, and exemplified by measurement of the strength of solid oxide fuel cell anode supports at 800 C. © 2014 Elsevier B.V. All rights reserved....

  14. Experimental programme in support of the development of the European ceramic-breeder-inside-tube test-blanket: present status and future work

    International Nuclear Information System (INIS)

    Proust, E.; Roux, N.; Flament, T.; Anzidei, L.; ENEA, Frascati; Casadio, S.; Dell'orco, G.

    1992-01-01

    Four DEMO blanket classes are under investigation within the framework of the European Test-Blanket Development Programme. One of them is featured by the use of lithium ceramic breeder pellets contained inside externally helium cooled tubes. This paper summarizes the main achievements to date of the experimental programme supporting the development of this class of blanket. It also gives an outline of the areas of the breeder material, beryllium, tritium control, and thermomechanical tests, the future work envisaged for the 92-94 period. 53 refs

  15. A simplified ultrafiltration method for determination of serum free cortisol

    International Nuclear Information System (INIS)

    MacMahon, W.; Sgoutas, D.

    1983-01-01

    The authors describe the suitability of the Amicon MPS-1 centrifugal ultrafiltration device and the YMB membrane for measuring free cortisol in serum. The method combines two independent assays: total cortisol and the ultrafiltrate fraction of added [ 3 H]cortisol. The unbound fraction is determined in 0.25-0.30 ml of ultrafiltrate collected from 0.6 to 1 ml of serum that has been equilibrated with [ 3 H]cortisol at 37 0 C for 20 min. The assay is rapid (less than 1 h), practical (no more than 0.6 ml of serum is necessary) and repeatable (CV: 3.8% within-assay and 12.2% in different assays). Error introduced in free cortisol measurement due to dilution effects in dialysis is systematically defined, and the effect of tracer purity on the ultrafiltration method is examined. Dialyzed sera from normal men and women, from patients with Cushing's disease and adrenal insufficiency, and from pregnant women gave ultrafiltration results that accurately duplicated those obtained by previous dialysis. (Auth.)

  16. In Vitro Comparison of Marginal and Internal Fit of Press-on-Metal Ceramic (PoM) Restorations with Zirconium-Supported and Conventional Metal Ceramic Fixed Partial Dentures Before and After Veneering.

    Science.gov (United States)

    Varol, Seda; Kulak-Özkan, Yasemin

    2015-07-01

    To compare marginal and internal fit between 3- and 4-unit press-on-metal (PoM) ceramic, zirconia-supported, and conventional metal ceramic fixed partial dentures (FPDs) before and after veneering. Ten pieces for each 3- and 4-unit MC, IPS InLine PoM, and IPS e.max ZirCAD/Zir Press FPDs were produced. Cross-sections from silicone replicas were examined and measured with a light microscope. Occlusal, axial, intermarginal, and marginal mean adaptation scores of cross-sectioned replicas and means of measurements obtained from 4 sites were calculated independently. Mean values for molars were 78.44 ± 32.01 μm (MC), 89.84 ± 29.20 μm (PoM), and 85.17 ± 28.49 μm (Zir). Premolar values were 76.08 ± 27.92 μm (MC), 89.94 ± 23.49 μm (PoM), and 87.18 ± 28.25 μm (Zir). No difference existed between the means of 3- and 4-unit FPDs except the molar-intermarginal region. The mean value of 4-unit FPDs (93.88 ± 25.41 μm) was less than the 3-unit FPDs (103.68 ± 24.55 μm) at the molar-inter marginal region. A gap increase was observed in all sites except the molar-axio-occlusal region after veneering. According to the mean difference, gap increases at the molar-marginal, molar-intermarginal, and premolar-intermarginal regions were statistically significant. A statistical difference was found at the molar-marginal region for 4-unit MCR (p = 0.041) and 4-unit PoM FPDs (p = 0.042) before and after veneering. Gap increase after veneering of 4-unit metal ceramics at molar-intermarginal, premolar-marginal, and premolar-intermarginal regions (p = 0.020; p = 0.015; p = 0.004) was significant. The gap measurements of the IPS InLine PoM and IPS e.max ZirCAD/Zir Press groups were all clinically acceptable. No studies on marginal and internal fit in the IPS InLine PoM system have been published to date. This study should be supported with future studies. No significant increase was observed after press-veneering the IPS e.max ZirCAD frameworks with an IPS e.max ZirPress material

  17. Treatment of olive mill wastewater by the combination of ultrafiltration and bipolar electrochemical reactor processes

    KAUST Repository

    Yahiaoui, O.; Lounici, Hakim; Abdi, Nadia; Drouiche, Nadjib; Ghaffour, NorEddine; Pauss, André ; Mameri, Nabil

    2011-01-01

    The main purpose of this study was to investigate the removal of the chemical oxygen demand (COD) from olive mill wastewater (OMW) by the combination of ultrafiltration with electrocoagulation process. Ultrafiltration process equipped with CERAVER

  18. Synthesis of carbon nanotubes by CVD method using iron and molybdenum-based catalysts supported on ceramic matrices

    International Nuclear Information System (INIS)

    Teixeira, Ana Paula de Carvalho

    2010-01-01

    Molybdenum is known for its synergistic effect in the synthesis of carbon nanotubes (CNs) by chemical vapor deposition (CVD method). When added to typical catalysts like iron, nickel, and cobalt, even in small quantities, it is increases the yield of these nanostructures. The presence of Mo also has an influence on the type and number of CN walls formed. Although this effect is widely documented in the literature, there is not yet a consensus about the mechanism of action of molybdenum in catalytic systems. The objective of the present work is to study the influence of molybdenum on the catalytic activity of iron nanoparticle-based catalysts supported on magnesium oxide (Fe/MgO system) in the synthesis of carbon nanotubes by the CVD method. The Mo concentration was systematically varied from null to molar ratio values four times greater than the quantity of Fe, and the obtained material (catalysts and carbon nanotubes) were broadly characterized by different techniques. In order to also study the influence of the preparation method on the final composition of the catalytic system phases, the catalytic systems (Fe/MgO e FeMo x /MgO) were synthesized by two different methods: co-precipitation and impregnation. The greatest CN yields were observed for the catalysts prepared by coprecipitation. The difference was attributed to better dispersion of the Fe and Mo phases in the catalyst ceramic matrix. In the precipitation stage, it was observed the formation of layered double hydroxides whose concentration increased with the Mo content up to the ratio of Mo/Fe equal to 0.2. This phase is related to a better distribution of Fe and Mo in this concentration range. Another important characteristic observed is that the ceramic matrix is not inert. It can react both with Fe and Mo and form the iron solid solution in the magnesium oxide and the phases magnesium-ferrite (MgFe 2 0 4 ) and magnesium molybdate (MgMo0 4 ). The MgFe 2 0 4 phase is observed in all catalytic systems

  19. The technical ceramics (second part)

    International Nuclear Information System (INIS)

    Auclerc, S.; Poulain, E.

    2004-01-01

    This work deals with ceramics used in the nuclear and the automotive industries. Concerning the nuclear sector, ceramics are particularly used in reactors, in the treatment of radioactive wastes and for the storage of the ultimate wastes. Details are given about the different ceramics used. In the automobile sector, aluminium is principally used for its lightness and cordierite, basic material of catalyst supports is especially used in the automobile devices of cleansing. (O.M.)

  20. Radiocarbon dating of VIRI bone samples using ultrafiltration

    Energy Technology Data Exchange (ETDEWEB)

    Minami, Masayo, E-mail: minami@nendai.nagoya-u.ac.jp [Center for Chronological Research, Nagoya University, Nagoya 464-8602 (Japan); Yamazaki, Kana [Faculty of Science, Nagoya University, Nagoya 464-8602 (Japan); Omori, Takayuki [University Museum, University of Tokyo, Tokyo 113-0033 (Japan); Nakamura, Toshio [Center for Chronological Research, Nagoya University, Nagoya 464-8602 (Japan)

    2013-01-15

    Ultrafiltration can effectively remove low-molecular-weight (LMW) contaminants from bone gelatin to extract high-molecular-weight (HMW) proteins that are derived from original bone collagen, though it cannot remove HMW collagen crosslinked with humic acids. Therefore, ultrafiltration is often used to obtain more accurate {sup 14}C dates of bones. However, ultrafiltration may introduce new contaminants to bone gelatins, mainly from ultrafilters used. To study the effects of ultrafiltration on {sup 14}C age, we analyzed the C/N ratio, {delta}{sup 13}C{sub PDB} and {delta}{sup 15}N{sub AIR} values, and {sup 14}C ages of acid-soluble bone collagen obtained by decalcification, gelatin extracted from acid-insoluble bone collagen, and the HMW gelatin and LMW fractions produced during ultrafiltration of the extracted gelatin. Bone samples from the Fifth International Radiocarbon Intercomparison (VIRI) were used: VIRI-E (mammoth), -F (horse), -G (human), and -I (whale). In this study, carbon and nitrogen content and gelatin yields were used to evaluate collagen preservation in the VIRI bone samples. Radiocarbon ages, {delta}{sup 13}C{sub PDB} and {delta}{sup 15}N{sub AIR} values of unfiltered and HMW gelatins were obtained and compared with the published consensus values. The LMW fraction was found to exhibit different values from those of the other fractions, indicating the possible presence of extraneous contamination. The Vivaspin Trade-Mark-Sign 6 ultrafilters used in this study were analyzed and radiocarbon dated both before and after cleaning. We present evidence to suggest that LMW fraction contaminants could be derived from the ultrafilters rather than humic substances. Excessively long ultrafiltration time was suspected to have contaminated the bone samples with material from the ultrafilter, because those samples exhibited older {sup 14}C ages than did those filtered for shorter durations. The results in this study indicate that {sup 14}C ages of unfiltered

  1. Treatment of the Bleaching Effluent from Sulfite Pulp Production by Ceramic Membrane Filtration

    Directory of Open Access Journals (Sweden)

    Mehrdad Ebrahimi

    2015-12-01

    Full Text Available Pulp and paper waste water is one of the major sources of industrial water pollution. This study tested the suitability of ceramic tubular membrane technology as an alternative to conventional waste water treatment in the pulp and paper industry. In this context, in series batch and semi-batch membrane processes comprising microfiltration, ultrafiltration and nanofiltration, ceramic membranes were developed to reduce the chemical oxygen demand (COD and remove residual lignin from the effluent flow during sulfite pulp production. A comparison of the ceramic membranes in terms of separation efficiency and performance revealed that the two-stage process configuration with microfiltration followed by ultrafiltration was most suitable for the efficient treatment of the alkaline bleaching effluent tested herein, reducing the COD concentration and residual lignin levels by more than 35% and 70%, respectively.

  2. Treatment of the Bleaching Effluent from Sulfite Pulp Production by Ceramic Membrane Filtration.

    Science.gov (United States)

    Ebrahimi, Mehrdad; Busse, Nadine; Kerker, Steffen; Schmitz, Oliver; Hilpert, Markus; Czermak, Peter

    2015-12-31

    Pulp and paper waste water is one of the major sources of industrial water pollution. This study tested the suitability of ceramic tubular membrane technology as an alternative to conventional waste water treatment in the pulp and paper industry. In this context, in series batch and semi-batch membrane processes comprising microfiltration, ultrafiltration and nanofiltration, ceramic membranes were developed to reduce the chemical oxygen demand (COD) and remove residual lignin from the effluent flow during sulfite pulp production. A comparison of the ceramic membranes in terms of separation efficiency and performance revealed that the two-stage process configuration with microfiltration followed by ultrafiltration was most suitable for the efficient treatment of the alkaline bleaching effluent tested herein, reducing the COD concentration and residual lignin levels by more than 35% and 70%, respectively.

  3. Ceramic joining

    Energy Technology Data Exchange (ETDEWEB)

    Loehman, R.E. [Sandia National Lab., Albuquerque, NM (United States)

    1996-04-01

    This paper describes the relation between reactions at ceramic-metal interfaces and the development of strong interfacial bonds in ceramic joining. Studies on a number of systems are described, including silicon nitrides, aluminium nitrides, mullite, and aluminium oxides. Joints can be weakened by stresses such as thermal expansion mismatch. Ceramic joining is used in a variety of applications such as solid oxide fuel cells.

  4. Sensitive Ceramics

    DEFF Research Database (Denmark)

    2014-01-01

    Sensitive Ceramics is showing an interactive digital design tool for designing wall like composition with 3d ceramics. The experiment is working on two levels. One which has to do with designing compositions and patterns in a virtual 3d universe based on a digital dynamic system that responds on ...... with realizing the modules in ceramics by 3d printing directly in porcelain with a RapMan printer that coils up the 3d shape in layers. Finally the ceramic modules are mounted in a laser cut board that reflects the captured composition of the movement of the hands....

  5. An improved ultrafiltration method for determining free testosterone in serum

    International Nuclear Information System (INIS)

    Vlahos, I.; MacMahon, W.; Sgoutas, D.; Bowers, W.; Thompson, J.; Trawick, W.

    1982-01-01

    In this method, we use the Amicon MPS-1 centrifugal ultrafiltration device and the YMB membrane in measuring free testosterone in serum. Two independent assays are combined: total testosterone and the ultrafiltrable fraction of added [ 3 H]testosterone. The unbound fraction is determined in 0.15-0.5 mL ultrafiltrates of 0.6 to 1 mL of variably diluted serum that has been equilibrated with [ 3 H]testosterone at 37 degrees C. The assay is rapid (less than 1 h), practicable (requires 0.6 mL of serum), and reproducible (CV 3.2% within assay, 3.9% between assays). Accuracy was evaluated as the fraction of free testosterone in the ultrafiltrate of dialyzed serum vs that in a prior dialysate; they were the same confirming the validity of the free testosterone measurement. Samples from ostensibly healthy men and women and from hirsute and pregnant women gave results that agreed with those obtained by equilibrium dialysis. Total testosterone concentrations for normal and hirsute women showed considerable overlap, but data on free testosterone concentrations in these populations were better resolved

  6. Effect of Time in Chemical Cleaning of Ultrafiltration Membranes

    NARCIS (Netherlands)

    Levitsky, I.; Naim, R.; Duek, A.; Gitis, V.

    2012-01-01

    Chemical cleaning of ultrafiltration membranes is often considered successful when the flux through a cleaned membrane is much higher than through a pristine one. Here, a novel definition of cleaning intensity is proposed as the product of the concentration of the cleaning agent and the cleaning

  7. Dynamic modeling of ultrafiltration membranes for whey separation processes

    NARCIS (Netherlands)

    Saltik, M.B.; Ozkan, L.; Jacobs, M.; van der Padt, A.

    2017-01-01

    In this paper, we present a control relevant rigorous dynamic model for an ultrafiltration membrane unit in a whey separation process. The model consists of a set of differential algebraic equations and is developed for online model based applications such as model based control and process

  8. Ultrafiltration concept for separating oil from water. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Goldsmith, R.L.; Schrab H.

    1973-01-01

    Discharge of oily wastes from shipboard operations of deballasting, bilge pumping, and slop tank cleaning constitutes a serious water pollution problem. Membrane ultrafiltration was studied in this project as a means of generating a highly purified water from a variety of oily wastes.

  9. Water hammer reduces fouling during natural water ultrafiltration.

    Science.gov (United States)

    Broens, F; Menne, D; Pothof, I; Blankert, B; Roesink, H D W; Futselaar, H; Lammertink, R G H; Wessling, M

    2012-03-15

    Today's ultrafiltration processes use permeate flow reversal to remove fouling deposits on the feed side of ultrafiltration membranes. We report an as effective method: the opening and rapid closing of a valve on the permeate side of an ultrafiltration module. The sudden valve closure generates pressure fluctuations due to fluid inertia and is commonly known as "water hammer". Surface water was filtrated in hollow fiber ultrafiltration membranes with a small (5%) crossflow. Filtration experiments above sustainable flux levels (>125 l (m2h)(-1)) show that a periodic closure of a valve on the permeate side improves filtration performance as a consequence of reduced fouling. It was shown that this effect depends on flux and actuation frequency of the valve. The time period that the valve was closed proved to have no effect on filtration performance. The pressure fluctuations generated by the sudden stop in fluid motion due to the valve closure are responsible for the effect of fouling reduction. High frequency recording of the dynamic pressure evolution shows water hammer related pressure fluctuations to occur in the order of 0.1 bar. The pressure fluctuations were higher at higher fluxes (higher velocities) which is in agreement with the theory. They were also more effective at higher fluxes with respect to fouling mitigation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Role of Peritoneal Ultrafiltration in Heart Failure Treatment

    Directory of Open Access Journals (Sweden)

    Tuba Elif Şenel

    2017-09-01

    Full Text Available Cardiorenal syndrome (CRS is a general term that can reflect different clinical conditions in which cardiac and renal dysfunctions coexist. The main pathogenetic mechanisms playing a role in heart failure (HF and CRS are neurohumoral adaptation, right ventricular dilatation and dysfunction and systemic inflammation. Persistence of these factors cause focal and segmental glomerulosclerosis, and tubulointerstitial fibrosis in the renal parenchyma. Diuretics, beta blockers, renin-angiotensin-aldosterone system inhibitors, and vasodilators are the main medical treatments besides conventional approach, such as salt and water restriction and quitting smoking, in HF treatment. Diuretic resistance is the main problem emerging during diuretic treatments. Two renal replacement treatments have become prominent for removal of excess fluids via ultrafiltration in HF patients with diuretic resistance extracorporeal ultrafiltration with hemodialysis and peritoneal dialysis (PD. Herein, the role of these two ultrafiltration modalities, especially peritoneal ultrafiltration (PUF in the treatment of HF is discussed. The main studies and advantages of PUF in HF treatment were discussed. Moreover, effects of PD on glomerular filtration rate, hospitalization and mortality were investigated. In conclusion, PD is an alternative cheap, practical and convenient therapy in reducing cardiac volume burden in HF patients who do not respond well to standard treatments and/or require frequent hospitalization.

  11. Ceramic combustor mounting

    Science.gov (United States)

    Hoffman, Melvin G.; Janneck, Frank W.

    1982-01-01

    A combustor for a gas turbine engine includes a metal engine block including a wall portion defining a housing for a combustor having ceramic liner components. A ceramic outlet duct is supported by a compliant seal on the metal block and a reaction chamber liner is stacked thereon and partly closed at one end by a ceramic bypass swirl plate which is spring loaded by a plurality of circumferentially spaced, spring loaded guide rods and wherein each of the guide rods has one end thereof directed exteriorly of a metal cover plate on the engine block to react against externally located biasing springs cooled by ambient air and wherein the rod spring support arrangement maintains the stacked ceramic components together so that a normal force is maintained on the seal between the outlet duct and the engine block under all operating conditions. The support arrangement also is operative to accommodate a substantial difference in thermal expansion between the ceramic liner components of the combustor and the metal material of the engine block.

  12. Work force retention: Role of work environment, organization commitment, supervisor support and training & development in ceramic sanitary ware industries in India

    Energy Technology Data Exchange (ETDEWEB)

    Umamaheswari S, Jayasree Krishnan

    2016-07-01

    Although retention of employees has become hot topic in this career turbulent era, practically no empirical research is carried out in the fast growing ceramic sector till now and this research fills the gap in the literature. The literatures surveys reported that organization commitment is an important determinant of retention and work environment, supervisor support and training and development are the most relevant antecedents increasing commitment towards organization. This paper examines the impact of the above factors over organization commitment and explores the effects of organization commitment on retention, and verifies the mediating effect of organization commitment on the relationship between proposed factors and retention. Design/methodology/approach: A survey was completed by 416 employees working in five ceramic sanitary ware factories located at different places in India. Questionnaire consisting of items adopted from previous researches were used to collect data. The selection of respondents was based on the simple random sampling. Findings: Findings reveals that organization commitment influences retention and all the above factors enhances it. Moreover organization commitment partially mediates the relationship between proposed factors and retention. However multiple regression analysis indicated that training and development did not have any notable influence on retention. Limitations: This study was conducted in a particular country and also in a particular sector of manufacturing industry, which limits generalization .Possibility of bias towards their organization and assumption that respondents know about their organization are other limitations. Implications: This paper offers recommendations to HR(Human resource) managers that they should extend their support to work environment, supervisor support and training and development in order to generate better relationship with employees and to reduce their likelihood of leaving the company

  13. Work force retention: Role of work environment, organization commitment, supervisor support and training & development in ceramic sanitary ware industries in India

    Directory of Open Access Journals (Sweden)

    Umamaheswari S

    2016-08-01

    Full Text Available Purpose: Although retention of employees has become hot topic in this career turbulent era, practically no empirical research is carried out in the fast growing ceramic sector till now and this research fills the gap in the literature. The literatures surveys reported that organization commitment is an important determinant of retention and work environment, supervisor support and training and development are the most relevant antecedents increasing commitment towards organization. This paper examines the impact of the above factors over organization commitment and explores the effects of organization commitment on retention, and verifies the mediating effect of organization commitment on the relationship between proposed factors and retention. Design/methodology/approach: A survey was completed by 416 employees working in five ceramic sanitary ware factories located at different places in India. Questionnaire consisting of items adopted from previous researches were used to collect data. The selection of respondents was based on the simple random sampling. Findings: Findings reveals that organization commitment influences retention and all the above factors enhances it. Moreover organization commitment partially mediates the relationship between proposed factors and retention. However multiple regression analysis indicated that training and development did not have any notable   influence on retention. Limitations: This study was conducted in a particular country and also in a particular sector of manufacturing industry, which limits generalization .Possibility of bias towards their organization and assumption that respondents know about their organization are other limitations. Implications: This paper offers recommendations to HR(Human resource managers that they should extend their support to work environment, supervisor support and training and development in order to generate better relationship with employees and to reduce their

  14. Experimental and computational investigation of polyacrylonitrile ultrafiltration membrane for industrial oily wastewater treatment

    International Nuclear Information System (INIS)

    Adib Hooman; Hassanajili, Shadi; Sheikhi-Kouhsar, Mohammad Reza; Salahi, Abdolhamid; Mohammadi, Toraj

    2015-01-01

    An experimental study on separation of industrial oil from oily wastewater has been done. A polyacrylonitrile membrane with a molecular weight cut-off (MWCO) of 20 kDa was used and an outlet wastewater of API unit of Tehran refinery was employed. The main purpose of this study was to develop a support vector machine model for permeation flux decline and fouling resistance in a cross-flow hydrophilic polyacrylonitrile membrane during ultrafiltration. The operating conditions which have been applied to develop a support vector machine model were transmembrane pressure (TMP), operating temperature, cross flow velocity (CFV), pH values of oily wastewater, permeation flux decline and fouling resistance. The testing results obtained by the support vector machine models are in very good agreement with experimental data. The calculated squared correlation coefficients for permeation flux decline and fouling resistance were both 0.99. Based on the results, the support vector machine proved to be a reliable accurate estimation method

  15. Experimental and computational investigation of polyacrylonitrile ultrafiltration membrane for industrial oily wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Adib Hooman; Hassanajili, Shadi; Sheikhi-Kouhsar, Mohammad Reza [Shiraz University, Shiraz (Iran, Islamic Republic of); Salahi, Abdolhamid; Mohammadi, Toraj [Iran University of Science and Technology (IUST), Tehran (Iran, Islamic Republic of)

    2015-01-15

    An experimental study on separation of industrial oil from oily wastewater has been done. A polyacrylonitrile membrane with a molecular weight cut-off (MWCO) of 20 kDa was used and an outlet wastewater of API unit of Tehran refinery was employed. The main purpose of this study was to develop a support vector machine model for permeation flux decline and fouling resistance in a cross-flow hydrophilic polyacrylonitrile membrane during ultrafiltration. The operating conditions which have been applied to develop a support vector machine model were transmembrane pressure (TMP), operating temperature, cross flow velocity (CFV), pH values of oily wastewater, permeation flux decline and fouling resistance. The testing results obtained by the support vector machine models are in very good agreement with experimental data. The calculated squared correlation coefficients for permeation flux decline and fouling resistance were both 0.99. Based on the results, the support vector machine proved to be a reliable accurate estimation method.

  16. Maximizing Production Capacity from an Ultrafiltration Process at the Hanford Department of Waste Treatment Facility

    International Nuclear Information System (INIS)

    Foust, Henry C.; Holton, Langdon K.; Demick, Laurence E.

    2005-01-01

    The Department of Energy has contracted Bechtel National, Inc. to design, construct and commission a Waste Treatment and Immobilization Plant (WTP) to treat radioactive slurry currently stored in underground waste storage tanks. A critical element of the waste treatment capacity for the WTP is the proper operation of an ultrafiltration process (UFP). The UFP separates supernate solution from radioactive solids. The solution and solid phases are separately immobilized. An oversight review of the UFP design and operation has identified several methods to improve the capacity of the ultrafiltration process, which will also improve the capacity of the WTP. Areas explored were the basis of design, an analysis of the WTP capacity, process chemistry within the UFP, and UFP process control. This article discusses some of the findings of this oversight review in terms of sodium and solid production, which supports the treatment of low activity waste (LAW) associated with the facility, and solid production, which supports the treatment of high level waste (HLW) associated with the facility

  17. [Ceramic posts].

    Science.gov (United States)

    Mainjot, Amélie; Legros, Caroline; Vanheusden, Alain

    2006-01-01

    As a result of ceramics and all-ceram technologies development esthetic inlay core and abutments flooded the market. Their tooth-colored appearance enhances restoration biomimetism principally on the marginal gingiva area. This article reviews indications and types of cores designed for natural teeth and implants.

  18. Nanopartículas catalisadoras suportadas por materiais cerâmicos Catalytic nanoparticles supported by ceramic materials

    Directory of Open Access Journals (Sweden)

    N. L. V. Carreño

    2002-09-01

    Full Text Available Neste trabalho são apresentados os procedimentos de preparação de materiais cerâmicos de SiO2, SnO2 e Al2O3 e, também, suas propriedades catalíticas nas reações de reforma do metano e do metanol. As análises dos resíduos de carbono, após testes catalíticos, sugerem que a modificação estrutural dos catalisadores pode minimizar os efeitos de sua desativação.This work presents the procedures for preparing SiO2, SnO2 and Al2O3 ceramic materials and also their catalytic properties for the reforming reactions of methane and methanol. The analyses of the carbonaceous residues suggest that the structural modification of the catalyst can minimize the deactivation effect upon them.

  19. ANL-1(A) - Development of nondestructive evaluation methods for structural ceramics

    International Nuclear Information System (INIS)

    Ellingson, W.A.; Roberts, R.A.; Gopalsami, N.; Dieckman, S.; Hentea, T.; Vaitekunas, J.J.

    1989-01-01

    This section includes the following papers: Development of Nondestructive Evaluation Methods for Structural Ceramics; Effects of Flaws on the Fracture Behavior of Structural Ceramics; Design, Fabrication, and Interface Characterization of Ceramic Fiber-Ceramic Matrix Composites; Development of Advanced Fiber-Reinforced Ceramics; Modeling of Fibrous Preforms for CVD Infiltration; NDT of Advanced Ceramic Composite Materials; Joining of Silicon Carbide Reinforced Ceramics; Superconducting Film Fabrication Research; Short Fiber Reinforced Structural Ceramics; Structural Reliability and Damage Tolerance of Ceramic Composites for High-Temperature Applications; Fabrication of Ceramic Fiber-Ceramic Matrix Composites by Chemical Vapor Infiltration; Characterization of Fiber-CVD Matrix interfacial Bonds; Microwave Sintering of Superconducting Ceramics; Improved Ceramic Composites Through Controlled Fiber-Matrix Interactions; Evaluation of Candidate Materials for Solid Oxide Fuel Cells; Ceramic Catalyst Materials: Hydrous Metal Oxide Ion-Exchange Supports for Coal Liquefaction; and Investigation of Properties and Performance of Ceramic Composite Components

  20. Study of the synthesis of TiO2 layers on macroporous ceramic supports in supercritical (SC) CO2 for processing radioactive aqueous effluents in dynamic mode

    International Nuclear Information System (INIS)

    Duchateau, Maxime

    2014-01-01

    Public and military nuclear industry generates a significant amount of radioactive liquid waste which must be treated before being released into the environment. Decontamination methods alternative to the industrial techniques (evaporation, chemical treatment) are being developed, such as column treatments or coupled filtration/sorption processes. Current researches mainly focus on the development and shaping of specific sorbents. In this context, the objectives of this thesis were first to study the synthesis of TiO 2 layers on macroporous ceramic supports in supercritical (SC) CO 2 and then to evaluate their potential for radionuclide extraction in these alternative processes. A robust synthesis method has been developed, based on the thermal decomposition of titanium isopropoxide in SC CO 2 in the temperature range between 150 C and 350 C. Nano-structured TiO 2 films were formed on the macroporous supports (ceramic foams, tubular α-alumina supports) with good adhesion, already at 150 C. The effect of the synthesis temperature on sorbents physico-chemical characteristics and sorption properties has been studied with TiO 2 powders prepared under the same conditions as the supported films. The best sorption performance were observed for the powder prepared at 150 C, owing to its higher density of surface sites in comparison with powders prepared at either 250 C or 350 C. Consequently, this synthesis temperature (150 C) was selected for a detailed study of the composite sorbents (TiO 2 /support), in order to assess their sorption performance in continuous treatment processes. The sorption experiments have shown that a column of alumina macroporous foam (Φpore = 400μm) coated with TiO 2 was suitable for processing effluents in dynamic mode with high throughputs. Both macro-pore sizes and column height were revealed as important parameters to be controlled. For the coupled filtration/sorption treatment, TiO 2 membranes exhibit good mechanical strength and are able

  1. Appropriateness of mechanistic and non-mechanistic models for the application of ultrafiltration to mixed waste

    International Nuclear Information System (INIS)

    Foust, Henry; Ghosehajra, Malay

    2007-01-01

    This study asks two questions: (1) How appropriate is the use of a basic filtration equation to the application of ultrafiltration of mixed waste, and (2) How appropriate are non-parametric models for permeate rates (volumes)? To answer these questions, mechanistic and non-mechanistic approaches are developed for permeate rates and volumes associated with an ultrafiltration/mixed waste system in dia-filtration mode. The mechanistic approach is based on a filtration equation which states that t/V vs. V is a linear relationship. The coefficients associated with this linear regression are composed of physical/chemical parameters of the system and based the mass balance equation associated with the membrane and associated developing cake layer. For several sets of data, a high correlation is shown that supports the assertion that t/V vs. V is a linear relationship. It is also shown that non-mechanistic approaches, i.e., the use of regression models to are not appropriate. One models considered is Q(p) = a*ln(Cb)+b. Regression models are inappropriate because the scale-up from a bench scale (pilot scale) study to full-scale for permeate rates (volumes) is not simply the ratio of the two membrane surface areas. (authors)

  2. Oxide ceramics

    International Nuclear Information System (INIS)

    Ryshkewitch, E.; Richerson, D.W.

    1985-01-01

    The book explores single-phase ceramic oxide systems from the standpoint of physical chemistry and technology. This second edition also focuses on advances in technology since publication of the original edition. These include improvements in raw materials and forming and sintering techniques, and the major role that oxide ceramics have had in development of advanced products and processes. The text is divided into five major sections: general fundamentals of oxide ceramics, advances in aluminum oxide technology, advances in zirconia technology, and advances in beryllium oxide technology

  3. Esthetic and Clinical Performance of Implant-Supported All-Ceramic Crowns Made with Prefabricated or CAD/CAM Zirconia Abutments: A Randomized, Multicenter Clinical Trial.

    Science.gov (United States)

    Wittneben, J G; Gavric, J; Belser, U C; Bornstein, M M; Joda, T; Chappuis, V; Sailer, I; Brägger, U

    2017-02-01

    Patients' esthetic expectations are increasing, and the options of the prosthetic pathways are currently evolving. The objective of this randomized multicenter clinical trial was to assess and compare the esthetic outcome and clinical performance of anterior maxillary all-ceramic implant crowns (ICs) based either on prefabricated zirconia abutments veneered with pressed ceramics or on CAD/CAM zirconia abutments veneered with hand buildup technique. The null hypothesis was that there is no statistically significant difference between the 2 groups. Forty implants were inserted in sites 14 to 24 (FDI) in 40 patients in 2 centers, the Universities of Bern and Geneva, Switzerland. After final impression, 20 patients were randomized into group A, restored with a 1-piece screw-retained single crown made of a prefabricated zirconia abutment with pressed ceramic as the veneering material using the cut-back technique, or group B using an individualized CAD/CAM zirconia abutment (CARES abutment; Institut Straumann AG) with a hand buildup technique. At baseline, 6 mo, and 1 y clinical, esthetic and radiographic parameters were assessed. Group A exhibited 1 dropout patient and 1 failure, resulting in a survival rate of 94.7% after 1 y, in comparison to 100% for group B. No other complications occurred. Clinical parameters presented stable and healthy peri-implant soft tissues. Overall, no or only minimal crestal bone changes were observed with a mean DIB (distance from the implant shoulder to the first bone-to-implant contact) of -0.15 mm (group A) and 0.12 mm (group B) at 1 y. There were no significant differences at baseline, 6 mo, and 1 y for DIB values between the 2 groups. Pink esthetic score (PES) and white esthetic score (WES) values at all 3 examinations indicated stability over time for both groups and pleasing esthetic outcomes. Both implant-supported prosthetic pathways represent a valuable treatment option for the restoration of single ICs in the anterior maxilla

  4. Bi-layered zirconia/fluor-apatite bridges supported by ceramic dental implants: a prospective case series after thirty months of observation.

    Science.gov (United States)

    Spies, Benedikt Christopher; Witkowski, Siegbert; Butz, Frank; Vach, Kirstin; Kohal, Ralf-Joachim

    2016-10-01

    The aim of this study was to determine the success and survival rate of all-ceramic bi-layered implant-supported three-unit fixed dental prostheses (IS-FDPs) 3 years after implant placement. Thirteen patients (seven males, six females; age: 41-78 years) received two one-piece ceramic implants (alumina-toughened zirconia) each in the region of the premolars or the first molar and were finally restored with adhesively cemented bi-layered zirconia-based IS-FDPs (3 in the maxilla, 10 in the mandible) composed of CAD/CAM-fabricated zirconia frameworks pressed-over with fluor-apatite glass-ceramic ingots. At prosthetic delivery and the follow-ups after 1, 2 and 3 years, the restorations were evaluated using modified United States Public Health Service (USPHS) criteria. Restorations with minor veneer chippings, a small-area occlusal roughness, slightly soundable restoration margins, minimal contour deficiencies and tolerable color deviations were regarded as success. In case of more distinct defects that could, however, be repaired to a clinically acceptable level, IS-FDPs were regarded as surviving. Kaplan-Meier plots were used for the success/survival analyses. To verify an impact on subjective patients' perceptions, satisfaction was evaluated by visual analog scales (VAS). All patients were seen 3 years after implant installation. No IS-FDP had to be replaced, resulting in 100% survival after a mean observation period of 29.5 months (median: 30.7). At the 3-year follow-up, 7/13 IS-FDPs showed a veneer chipping, 13/13 an occlusal roughness and 12/13 minimal deficiencies of contour/color. Since six restorations showed a major chipping and/or a major occlusal roughness, the Kaplan-Meier success rate was 53.8%. However, patients' significantly improved perceptions of function, esthetics, sense, and speech at prosthetic delivery remained stable over time. Bi-layered zirconia/fluor-apatite IS-FDPs entirely survived the observation period but showed a high frequency of

  5. The determination of ultrafiltrable calcium and magnesium in serum.

    Science.gov (United States)

    Danielson, B G; Pallin, E; Sohtell, M

    1982-01-01

    Ultrafiltrate of human serum was investigated in order to evaluate the serum content of calcium and magnesium. The acid and base concentrations and pH of the serum was altered through titration with HCl- or NaOH-solutions. The Pco2 was varied in the titrated serum using different carbon dioxide tensions. This was performed when serum was filtered in a recycling system. It is shown that the analysis of calcium and magnesium have to be done under anaerobic conditions or at standardized pH and Pco2 situations, as the concentrations vary with both pH and Pco2. The concentration ratio between ultrafiltrate and serum for calcium and magnesium was found to be 0.56 and 0.74 respectively at pH=7.41 and Pco2=40 mmHg.

  6. OXYGEN TRANSPORT CERAMIC MEMBRANES

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

    2000-10-01

    This is the third quarterly report on oxygen Transport Ceramic Membranes. In the following, the report describes the progress made by our university partners in Tasks 1 through 6, experimental apparatus that was designed and built for various tasks of this project, thermodynamic calculations, where applicable and work planned for the future. (Task 1) Design, fabricate and evaluate ceramic to metal seals based on graded ceramic powder/metal braze joints. (Task 2) Evaluate the effect of defect configuration on ceramic membrane conductivity and long term chemical and structural stability. (Task 3) Determine materials mechanical properties under conditions of high temperatures and reactive atmospheres. (Task 4) Evaluate phase stability and thermal expansion of candidate perovskite membranes and develop techniques to support these materials on porous metal structures. (Task 5) Assess the microstructure of membrane materials to evaluate the effects of vacancy-impurity association, defect clusters, and vacancy-dopant association on the membrane performance and stability. (Task 6) Measure kinetics of oxygen uptake and transport in ceramic membrane materials under commercially relevant conditions using isotope labeling techniques.

  7. Recovery of carbohydrates from nixtamalization wastewaters (nejayote) by ultrafiltration

    OpenAIRE

    Castro-Muñoz, R.; Cerón-Montes, G.I.; Barragán-Huerta, B.E.; Yáñez-Fernández, J.

    2015-01-01

    Nejayote extract is a polluting by-product from Nixtamalization of maize; therefore in this study was evaluated a membrane operation for the treatment and recovery of industrial usable compounds. Nejayote extract was processed by ultrafiltration (UF) membrane on laboratory scale. In experimental tests performed according to the total recycle mode, the effect of transmembrane pressure (TMP) on permeate flux has been studied. The permeate flux no showed a considerable increase for TMP values hi...

  8. A fractographic study of clinically retrieved zirconia–ceramic and metal–ceramic fixed dental prostheses

    OpenAIRE

    Pang, Zhen; Chughtai, Asima; Sailer, Irena; Zhang, Yu

    2015-01-01

    A recent 3-year randomized controlled trial (RCT) of tooth supported three- to five-unit zirconia-ceramic and metal-ceramic posterior fixed dental prostheses (FDPs) revealed that veneer chipping and fracture in zirconia-ceramic systems occurred more frequently than those in metal-ceramic systems [1]. This study seeks to elucidate the underlying mechanisms responsible for the fracture phenomena observed in this RCT using a descriptive fractographic analysis

  9. Selective separation of Eu3+ using polymer-enhanced ultrafiltration

    International Nuclear Information System (INIS)

    Norton, M.V.

    1994-03-01

    A process to selectively remove 241 Am from liquid radioactive waste was investigated as an actinide separation method applicable to Hanford and other waste sites. The experimental procedures involved removal of Eu, a nonradioactive surrogate for Am, from aqueous solutions at pH 5 using organic polymers in conjunction with ultrafiltration. Commercially available polyacrylic acid (60,000 MW) and Pacific Northwest Laboratory's (PNL) synthesized E3 copolymer (∼10,000 MW) were tested. Test solutions containing 10 μg/mL of Eu were dosed vath each polymer at various concentrations in order to bind Eu (i.e., by complexation and/or cation exchange) for subsequent rejection by an ultrafiltration coupon. Test solutions were filtered with and without polymer to determine if enhanced Eu separation could be achieved from polymer treatment. Both polymers significantly increased Eu removal. Optimum concentrations were 20 μg/mL of polyacrylic acid and 100 μg/mL of E3 for 100% Eu rejection by the Amicon PM10 membrane at 55 psi. In addition to enhancement of removal, the polymers selectively bound Eu over Na, suggesting that selective separation of Eu was possible. This suggests that polymer-enhanced ultrafiltration is a potential process for separation of 241 Am from Hanford tank waste, further investigation of binding agents and membranes effective under very alkaline and high ionic strength is warranted. This process also has potential applications for selective separation of toxic metals from industrial process streams

  10. Oily bilge water treatment with a tubular ultrafiltration system

    Energy Technology Data Exchange (ETDEWEB)

    Harris, L.R.; Jackson, D.F.; Schatzberg, P.

    1976-11-01

    The Navy has been developing various oil pollution abatement systems. One potential process for the separation of oil in bilge water is ultrafiltration, a pressure-driven membrane process which can separate, concentrate, and fractionate macromolecular solutes and suspended species from water. A tubular ultrafiltration system using cellulosic and noncellulosic membranes was tested with bilge oil obtained from a patrol craft. Tests were also conducted with tap water, river water, a turbine lubricating oil, and a fuel oil, alone and in combination with a nonionic detergent. The addition of the detergent was observed to result in a steeper flux decline than when any of the fluids were evaluated alone. Both membrane types produced a permeate with an oil content generally less than 15 mg/l. Although the noncellulosic membranes exhibited higher flux rates than the cellulosic membranes, only the former could be restored by a cleaning operation to its initial water flux after experiencing a decline in flux. A cumulative irreversible flux decline was exhibited by the cellulosic membrane. Cleaning operations, some of which were time-consuming, consisted of flushing the membrane with ultrafiltrate, distilled water, tap water, or the manufacturer's enzyme-detergent formulation. Only the last of these, when employed at elevated temperature (125/sup 0/F), restored the initial water flux of the noncellulosic membrane.

  11. Removal of uranium and thorium from aqueous solution by ultrafiltration (UF) and PAMAM dendrimer assisted ultrafiltration (DAUF)

    International Nuclear Information System (INIS)

    Ilaiyaraja, P.; Ashish Kumar Singha Deb; Ponraju, D.

    2015-01-01

    Studies on removal of U(VI) and Th(IV) from aqueous solution have been carried out by ultrafiltration (UF) and dendrimer assisted ultrafiltration (DAUF) using regenerated cellulose acetate membrane and PAMAM [poly(amido)amine] dendrimer chelating agent. In UF, the U(VI) and Th(IV) are removed from aqueous solution by adsorption/mass deposition on the membrane at pH > 4. In DAUF, the water soluble PAMAM dendrimer chelating agent effectively concentrates these metal ions in retentate thereby preventing the mass deposition on membrane. At acidic pH (≤3), the binding of metal ions with PAMAM dendrimer is very weak and hence PAMAM can be regenerated and reused. Electronic supplementary material. The online version of this article (doi:10.1007/s10967-014-3462-x) contains supplementary material, which is available to authorized users. (author)

  12. Development of Refractory Ceramics for The Oxygen Evolution Reaction (OER) Electrocatalyst Support for Water Electrolysis at elevated temperatures

    DEFF Research Database (Denmark)

    Nikiforov, Aleksey; Prag, Carsten Brorson; Polonsky, J.

    2012-01-01

    Commercial TaC and Si3N4 powders were tested as possible electrocatalyst support materials for the Oxygen Evolution Reaction (OER) for PEM water electrolysers, operating at elevated temperatures. TaC and Si3N4 were characterised by thermogravimmetric and differential thermal analysis...

  13. Microstructural properties of non-supported microporous ceramic membrane top-layers obtained by the sol-gel process

    NARCIS (Netherlands)

    de Lange, Rob; de Lange, R.S.A.; Hekkink, J.H.A.; Hekkink, J.H.A.; Keizer, Klaas; Burggraaf, Anthonie; Burggraaf, A.J.

    1996-01-01

    Dried and calcined non-supported membrane top-layers of SiO2, SiO2/TiO2, SiO2/ZrO2 (10, 20 and 30 mol% TiO2 and ZrO2, respectively) and SiO2/Al2O3 (10 mol% AlO1.5) were prepared using acid catalyzed hydrolysis and condensation of alkoxides in ethanol. The microstructure was determined using nitrogen

  14. Ultrafiltration Membrane Fouling and the Effect of Ion Exchange Resins

    KAUST Repository

    Jamaly, Sanaa

    2011-12-01

    Membrane fouling is a challenging process for the ultrafiltration membrane during wastewater treatment. This research paper determines the organic character of foulants of different kinds of wastewater before and after adding some ion exchange resins. Two advanced organic characterization methods are compared in terms of concentration of dissolved organic carbons: The liquid chromatography with organic carbon (LC-OCD) and Shimadzu total organic carbon (TOC). In this study, two secondary wastewater effluents were treated using ultrafiltration membrane. To reduce fouling, pretreatment using some adsorbents were used in the study. Six ion exchange resins out of twenty were chosen to compare the effect of adsorbents on fouling membrane. Based on the percent of dissolved organic carbon’s removal, three adsorbents were determined to be the most efficient (DOWEX Marathon 11 anion exchange resin, DOWEX Optipore SD2 polymeric adsorbent, and DOWEX PSR2 anion exchange), and three other ones were determined to the least efficient (DOWEX Marathon A2 anion exchange resin, DOWEX SAR anion exchange resin, and DOWEX Optipore L493 polymeric adsorbent). Organic characterization for feed, permeate, and backwash samples were tested using LC-OCD and TOC to better understand the characteristics of foulants to prevent ultrafiltration membrane fouling. The results suggested that the polymeric ion exchange resin, DOWEX SD2, reduced fouling potential for both treated wastewaters. All the six ion exchange resins removed more humic fraction than other organic fractions in different percent, so this fraction is not the main for cause for UF membrane fouling. The fouling of colloids was tested before and after adding calcium. There is a severe fouling after adding Ca2+ to effluent colloids.

  15. Ultrafiltration treatment for liquid laundry wastes from nuclear power stations

    International Nuclear Information System (INIS)

    Kichik, V.A.; Maslova, M.N.; Svittsov, A.A.; Kuleshov, N.F.

    1988-01-01

    The authors conduct a comprehensive analysis of the waste constituents--radioactive and organic--of the laundry water resulting from the on-site laundering and decontamination of clothing worn in nuclear power plants. The primary isotope contaminants consist of niobium and zirconium 95, manganese 54, cobalt 60, iron 59, and cesium 134 and 137. A variety of filter and adsorbent materials used in an ultrafiltration process are comparatively tested for their effectiveness in removing not only these isotopes but also the organic contaminants in the process of recycling the water. Those materials consist of copper hexacyanoferrate, polyacrylophosphonic acid, and several metal-polymer complexes

  16. Operating considerations of ultrafiltration in enzyme enhanced carbon capture

    DEFF Research Database (Denmark)

    Deslauriers, Maria Gundersen; Gladis, Arne; Fosbøl, Philip Loldrup

    2017-01-01

    capture capacity of 1 MTonn CO2/year, and is here operated for one year continuously. This publication compares soluble enzymes dissolved in a capture solvent with and without the use of ultrafiltration membranes. The membranes used here have an enzyme retention of 90%, 99% and 99.9%. Enzyme retention......Today, enzyme enhanced carbon capture and storage (CCS) is gaining interest, since it can enable the use of energy efficient solvents, and thus potentially reduce the carbon footprint of CCS. However, a limitation of this technology is the high temperatures encountered in the stripper column, which...

  17. Ceramic Seal.

    Energy Technology Data Exchange (ETDEWEB)

    Smartt, Heidi A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Romero, Juan A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Custer, Joyce Olsen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hymel, Ross W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Krementz, Dan [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Gobin, Derek [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Harpring, Larry [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Martinez-Rodriguez, Michael [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Varble, Don [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); DiMaio, Jeff [Tetramer Technologies, Pendleton, SC (United States); Hudson, Stephen [Tetramer Technologies, Pendleton, SC (United States)

    2016-11-01

    Containment/Surveillance (C/S) measures are critical to any verification regime in order to maintain Continuity of Knowledge (CoK). The Ceramic Seal project is research into the next generation technologies to advance C/S, in particular improving security and efficiency. The Ceramic Seal is a small form factor loop seal with improved tamper-indication including a frangible seal body, tamper planes, external coatings, and electronic monitoring of the seal body integrity. It improves efficiency through a self-securing wire and in-situ verification with a handheld reader. Sandia National Laboratories (SNL) and Savannah River National Laboratory (SRNL), under sponsorship from the U.S. National Nuclear Security Administration (NNSA) Office of Defense Nuclear Nonproliferation Research and Development (DNN R&D), have previously designed and have now fabricated and tested Ceramic Seals. Tests have occurred at both SNL and SRNL, with different types of tests occurring at each facility. This interim report will describe the Ceramic Seal prototype, the design and development of a handheld standalone reader and an interface to a data acquisition system, fabrication of the seals, and results of initial testing.

  18. Ceramic Seal

    International Nuclear Information System (INIS)

    Smartt, Heidi A.; Romero, Juan A.; Custer, Joyce Olsen; Hymel, Ross W.; Krementz, Dan; Gobin, Derek; Harpring, Larry; Martinez-Rodriguez, Michael; Varble, Don; DiMaio, Jeff; Hudson, Stephen

    2016-01-01

    Containment/Surveillance (C/S) measures are critical to any verification regime in order to maintain Continuity of Knowledge (CoK). The Ceramic Seal project is research into the next generation technologies to advance C/S, in particular improving security and efficiency. The Ceramic Seal is a small form factor loop seal with improved tamper-indication including a frangible seal body, tamper planes, external coatings, and electronic monitoring of the seal body integrity. It improves efficiency through a self-securing wire and in-situ verification with a handheld reader. Sandia National Laboratories (SNL) and Savannah River National Laboratory (SRNL), under sponsorship from the U.S. National Nuclear Security Administration (NNSA) Office of Defense Nuclear Nonproliferation Research and Development (DNN R&D), have previously designed and have now fabricated and tested Ceramic Seals. Tests have occurred at both SNL and SRNL, with different types of tests occurring at each facility. This interim report will describe the Ceramic Seal prototype, the design and development of a handheld standalone reader and an interface to a data acquisition system, fabrication of the seals, and results of initial testing.

  19. Synthesis of ceramic hollow fiber supported zeolitic imidazolate framework-8 (ZIF-8) membranes with high hydrogen permeability

    KAUST Repository

    Pan, Yichang; Wang, Bo; Lai, Zhiping

    2012-01-01

    Purification and recovery of hydrogen from hydrocarbons in refinery streams in the petrochemical industry is an emerging research field in the study of membrane gas separation. Hollow fiber membrane modules can be easily implemented into separation processes at the industrial scale. In this report, hollow yttria-stabilized zirconia (YSZ) fiber-supported zeolitic imidazole framework-8 (ZIF-8) membranes were successfully prepared using a mild and environmentally friendly seeded growth method. Our single-component permeation studies demonstrated that the membrane had a very high hydrogen permeance (~15×10 -7mol/m 2sPa) and an ideal selectivity of H 2/C 3H 8 of more than 1000 at room temperature. This high membrane permeability and selectivity caused serious concentration polarization in the separation of H 2/C 3H 8 mixtures, which led to almost 50% drop in both the H 2 permeance and the separation factor. Enhanced mixing on the feed side could reduce the effect of the concentration polarization. Our experimental data also indicated that the membranes had excellent reproducibility and long-term stability, indicating that the hollow fiber-supported ZIF-8 membranes developed in this study have great potential in industry-scale separation of hydrogen. © 2012 Elsevier B.V.

  20. Synthesis of ceramic hollow fiber supported zeolitic imidazolate framework-8 (ZIF-8) membranes with high hydrogen permeability

    KAUST Repository

    Pan, Yichang

    2012-12-01

    Purification and recovery of hydrogen from hydrocarbons in refinery streams in the petrochemical industry is an emerging research field in the study of membrane gas separation. Hollow fiber membrane modules can be easily implemented into separation processes at the industrial scale. In this report, hollow yttria-stabilized zirconia (YSZ) fiber-supported zeolitic imidazole framework-8 (ZIF-8) membranes were successfully prepared using a mild and environmentally friendly seeded growth method. Our single-component permeation studies demonstrated that the membrane had a very high hydrogen permeance (~15×10 -7mol/m 2sPa) and an ideal selectivity of H 2/C 3H 8 of more than 1000 at room temperature. This high membrane permeability and selectivity caused serious concentration polarization in the separation of H 2/C 3H 8 mixtures, which led to almost 50% drop in both the H 2 permeance and the separation factor. Enhanced mixing on the feed side could reduce the effect of the concentration polarization. Our experimental data also indicated that the membranes had excellent reproducibility and long-term stability, indicating that the hollow fiber-supported ZIF-8 membranes developed in this study have great potential in industry-scale separation of hydrogen. © 2012 Elsevier B.V.

  1. Flux, rejection and fouling during microfiltration and ultrafiltration of sugar palm sap using a pilot plant scale

    Directory of Open Access Journals (Sweden)

    Wanichapichart, P.

    2006-07-01

    Full Text Available The possibility of using a pilot plant scale microfiltration (MF and ultrafiltration (UF to clarify and reduce number of bacteria, yeast and mould of sugar palm sap was studied. The membrane used was multi channel tubular ceramic membrane (ZrO2-TiO2 with membrane pore size 0.2 and 0.1 μm and molecular weight cut off (MWCO 300 and 50 kDa for microfiltration and ultrafiltration respectively. The experiment was carried out to investigate the rejection of the components in sugar palm sap, permeate flux and fouling characteristics. The results showed that the turbidity, the total solid, the viscosity and the numbers of bacteria, yeast and mould in the permeate obtained by MF and UF were reduced significantly compared to those of fresh sugar palm sap. The total soluble solid, total sugar, reducing sugar and pH were not affected by MF and UF. The permeate fluxes for all membranes were reduced greatly as the volume concentration ratio (VCR increased due to severe fouling. The irreversible fouling on membrane surface and/or inside the membrane tended to increase with increasing membrane pore size or MWCO. The result also suggested that protein and small particle in the sugar palm sap were probably responsible for the internal fouling of large pore size membrane. According to the physical, chemical and microorganism quality results, both MF and UF showed the potential use for improving the quality of sugar palm sap but flux reduction due to fouling was a major problem affecting the process performance.

  2. Ni-Pd-Al2O3 catalyst supported on reticulated ceramic foam for dry methane reforming

    Directory of Open Access Journals (Sweden)

    Vesna Nikolić

    2015-03-01

    Full Text Available In the present study, Ni-Pd/Al2O3 catalyst supported on α-Al2O3 based foam was prepared and evaluated in the dry methane reforming process. Corresponding metal chlorides were deposited to the foam surface by impregnation of the foam with ultrasonically aerosolized salt solutions at 473 K and drying at that temperature. Calcination step was excluded and the catalyst was reduced at very low temperature – 533 K. The reforming experiment lasted for 3 h, with standing time of 1 h at the following temperatures: 873, 973 and 1023 K. Conclusions on selectivity, catalytic activity and stability were reached on the basis of CO and H2 yields.

  3. Size enlargement of radioactive and hazardous species and their separation by microfiltration and ultrafiltration membranes

    International Nuclear Information System (INIS)

    Vijayan, S.; Wong, C.F.; Buckley, L.P.

    1993-01-01

    Separation and volume reduction of aqueous solutions involving membranes is evolving into an expanding and diversified field. Numerous commercially successful membranes and their applications are now available. Among different driving forces used in membrane separation, pressure-driven separation has gained wide application. Depending on the size of the dissolved species in solution to be separated, the pressure needed to achieve the desired separation varies. The microfiltration and ultrafiltration membrane systems are low-pressure processes that generally operate below 350 kPa. To exploit these membranes in applications involving the removal of dissolved contaminants from solutions, it is essential to create a suitable size for the dissolved contaminants, so that the membranes can effectively retain them while producing a filtrate stream essentially free of contaminants. Size enlargement of the dissolved contaminants can be achieved through solution conditioning with the addition of one or a combination of chemical reagents and powdered materials. Examples of typical additives include: pH chemicals, polyelectrolytes, microorganisms and powdered adsorption/ion-exchange materials. In many situations, adequate control and optimization of the system chemistry and hydraulic conditions provide high selectivity and efficiency for contaminant removal. This paper summarizes removal efficiency data for cadmium, lead, mercury, uranium, arsenic, strontium-90/85, cesium-137 and iron. These data resulted from various initiatives on membrane technology undertaken during the past five years by the Waste Processing Technology group at Chalk River Laboratories. The technology involves size enlargement of contaminants present in waste solution, and their separation using either microfiltration or ultrafiltration. The data support remedial applications involving treatment of contaminated groundwater and soils

  4. Low fouling polysulfone ultrafiltration membrane via click chemistry

    KAUST Repository

    Xie, Yihui

    2014-10-13

    Hydrophilic surfaces are known to be less prone to fouling. Ultrafiltration membranes are frequently prepared from rather hydrophobic polymers like polysulfone (PSU). Strategies to keep the good pore forming characteristics of PSU, but with improved hydrophilicity are proposed here. PSU functionalized with 1,2,3-triazole ring substituents containing OH groups was successfully synthesized through click chemistry reaction. The structures of the polymers were confirmed using NMR spectroscopy and Fourier transform infrared spectroscopy (FTIR). High thermal stability (>280°C) was observed by thermal gravimetric analysis. Elemental analysis showed the presence of nitrogen containing triazole group with different degrees of functionalization (23%, 49%, 56%, and 94%). The glass transition temperature shifted with the introduction of triazole pendant groups from 190°C (unmodified) to 171°C. Ultrafiltration membranes were prepared via phase inversion by immersion in different coagulation baths (NMP/water mixtures with volume ratios from 0/100 to 40/60). The morphologies of these membranes were studied by field emission scanning electron microscopy (FESEM). The optimized PSU bearing triazole functions membranes exhibited water permeability up to 187 L m-2 h-1 bar-1, which is 23 times higher than those prepared under the same conditions but with unmodified polysulfone (PSU; 8 L m-2 h-1 bar-1). Results of bovine serum albumin protein rejection test indicated that susceptibility to fouling decreased with the modification, due to the increased hydrophilicity, while keeping high protein rejection ratio (>99%).

  5. Ultra-filtration measurement using CT imaging technology

    International Nuclear Information System (INIS)

    Lu Junfeng; Lu Wenqiang

    2009-01-01

    As a functional unit in the hemodialysis process, dialyzer captured quite a few medical research interests since 1980s. In the design of dialyzer or in the ongoing hemodialysis process, to estimate the ultra-filtration amount of a dialyzer, the sideway loss of the running blood flow through hollow fibers or filtration channels should be measured. This further leads to the measurement of the blood flow inside the dialyzer. For this measurement, a non-invasive method is highly desired because of the high-dense bundled hollow fibers or packed channels inside the dialyzer. As non-invasive measurement tools, CT (Computed Tomography) technologies were widely used for tissue, bone, and cancerous clinical analyses etc .... Thus, in this paper, a CT system is adopted to predict the blood flow inside a hollow fiber dialyzer. In view of symmetric property of the hollow fiber dialyzer, the largest cutting plane that parallels to the cylindrical dialyzer was analyzed by the CT system dynamically. And then, a noninvasive image analysis method used to predict the ultra-filtration amount is proposed.

  6. ULTRAFILTRATION AS PRETREATMENT OF REVERSE OSMOSIS: LOW FOULING ULTRAFILTRATION MEMBRANE PREPARED FROM POLYETHERSULFONE–AMPHIPHILIC BLOCK COPOLYMER BLEND

    Directory of Open Access Journals (Sweden)

    Heru Susanto

    2012-02-01

    Full Text Available This paper demonstrates the preparation of polyethersulfone (PES ultrafiltration (UF membranes via wet phase inversion method using either poly(ethylene oxide-b-poly(propylene oxide-b- poly(ethylene oxide (Pluronic®, Plu or polyethylene glycol (PEG as hydrophilic modifier. Their effects on membrane structure as well as the resulting membrane performance and their stability in membrane polymer matrix were systematically investigated. The investigated membrane characteristics include surface hydrophilicity (by contact angle, surface chemistry (by FTIR spectroscopy and water flux measurement. Visualization of membrane surface and cross section morphology was also done by scanning electron microscopy. The membrane performance was examined by investigation of adsorptive fouling and ultrafiltration using solution of bovine serum albumin as the model system. The stability of additive was examined by incubating the membrane in water (40oC for up to 10 days. The results show that modification effects on membrane characteristic and low fouling behavior were clearly observed. Further, amphiphilic Pluronic generally showed better performance than PEG.   

  7. Industrial ceramics

    International Nuclear Information System (INIS)

    Mengelle, Ch.

    1999-04-01

    After having given the definition of the term 'ceramics', the author describes the different manufacturing processes of these compounds. These materials are particularly used in the fields of 1)petroleum industry (in primary and secondary reforming units, in carbon black reactors and ethylene furnaces). 2)nuclear industry (for instance UO 2 and PuO 2 as fuels; SiC for encapsulation; boron carbides for control systems..)

  8. The use of ceramic membranes for radioactive solutions purification

    International Nuclear Information System (INIS)

    Zakrzewska-Trznadel, G.

    2002-01-01

    Membrane permeation combined with complexation was tested for radioactive wastes processing purpose. The results of experiments with MEMBRALOX and CeRAM INSIDE filtering elements are presented in the paper. The pore size of ceramic membranes was in 1kD-100 nm range. The experiments were performed with non-active and with radioactive model solutions and original radioactive waste samples. To achieve high decontamination factors the process was enhanced by chemical complexation. Such complexants as poly(acrylic) acid and polyacrylic)acid salts of different crosslinking, polyethylenimine and cyanoferrates were tested. The experiments showed the significant increase of retention and decontamination factors while before ultrafiltration macromolecular ligands were added. The effectiveness of complexation by each ligand is strongly dependent on pH and alkali metals concentration. (author)

  9. Characterization of the interaction between glazes and ceramic bodies

    Czech Academy of Sciences Publication Activity Database

    Kavanová, M.; Kloužková, A.; Kloužek, Jaroslav

    2017-01-01

    Roč. 61, č. 3 (2017), s. 267-275 ISSN 0862-5468 Institutional support: RVO:67985891 Keywords : glazes * ceramic s * thermal analysis * coefficients of the thermal expansion * dilatometry Subject RIV: JH - Ceramic s, Fire-Resistant Materials and Glass OBOR OECD: Ceramic s Impact factor: 0.439, year: 2016

  10. Effect of membrane hydrophilization on ultrafiltration performance for biomolecules separation

    International Nuclear Information System (INIS)

    Susanto, H.; Roihatin, A.; Aryanti, N.; Anggoro, D.D.; Ulbricht, M.

    2012-01-01

    This paper compares the performance of different hydrophilization methods to prepare low fouling ultrafiltration (UF) membranes. The methods include post-modification with hydrophilic polymer and blending of hydrophilic agent during either conventional or reactive phase separation (PS). The post-modification was done by photograft copolymerization of water-soluble monomer, poly(ethylene glycol) methacrylate (PEGMA), onto a commercial polyethersulfone (PES) UF membrane. Hydrophilization via blend polymer membrane with hydrophilic additive was performed using non-solvent induced phase separation (NIPS). In reactive PS method, the cast membrane was UV-irradiated before coagulation. The resulting membrane characteristic, the performance and hydrophilization stability were systematically compared. The investigated membrane characteristics include surface hydrophilicity (by contact angle /CA/), surface chemistry (by FTIR spectroscopy), and surface morphology (by scanning electron microscopy). The membrane performance was examined by investigation of adsorptive fouling and ultrafiltration using solution of protein or polysaccharide or humic acid. The results suggest that all methods could increase the hydrophilicity of the membrane yielding less fouling. Post-modification decreased CA from 44.8 ± 4.2 o to 37.8 ± 4.2 o to 42.5 ± 4.3 o depending on the degree of grafting (DG). The hydrophilization via polymer blend decreased CA from from 65 deg. to 54 deg. for PEG concentration of 5%. Nevertheless, decreasing hydraulic permeability was observed after post-modification as well as during polymer blend modification. Stability examination showed that there was leaching out of modifier agent from the membrane matrix prepared via conventional PS after 10 days soaking in both water and NaOH. Reactive PS could increase the stability of the modifier agent in membrane matrix. Highlights: ► We compared different methods to prepare low fouling ultrafiltration (UF) membranes.

  11. Effect of membrane hydrophilization on ultrafiltration performance for biomolecules separation

    Energy Technology Data Exchange (ETDEWEB)

    Susanto, H., E-mail: heru.susanto@undip.ac.id [Department of Chemical Engineering, Universitas Diponegoro, Jl. Prof. Sudarto-Tembalang, Semarang (Indonesia); Roihatin, A.; Aryanti, N.; Anggoro, D.D. [Department of Chemical Engineering, Universitas Diponegoro, Jl. Prof. Sudarto-Tembalang, Semarang (Indonesia); Ulbricht, M. [Lehrstuhl fuer Technische Chemie, Universitaet Duisburg-Essen, Germany, Universitaetstr. 5, Essen (Germany)

    2012-10-01

    This paper compares the performance of different hydrophilization methods to prepare low fouling ultrafiltration (UF) membranes. The methods include post-modification with hydrophilic polymer and blending of hydrophilic agent during either conventional or reactive phase separation (PS). The post-modification was done by photograft copolymerization of water-soluble monomer, poly(ethylene glycol) methacrylate (PEGMA), onto a commercial polyethersulfone (PES) UF membrane. Hydrophilization via blend polymer membrane with hydrophilic additive was performed using non-solvent induced phase separation (NIPS). In reactive PS method, the cast membrane was UV-irradiated before coagulation. The resulting membrane characteristic, the performance and hydrophilization stability were systematically compared. The investigated membrane characteristics include surface hydrophilicity (by contact angle /CA/), surface chemistry (by FTIR spectroscopy), and surface morphology (by scanning electron microscopy). The membrane performance was examined by investigation of adsorptive fouling and ultrafiltration using solution of protein or polysaccharide or humic acid. The results suggest that all methods could increase the hydrophilicity of the membrane yielding less fouling. Post-modification decreased CA from 44.8 {+-} 4.2{sup o} to 37.8 {+-} 4.2{sup o} to 42.5 {+-} 4.3{sup o} depending on the degree of grafting (DG). The hydrophilization via polymer blend decreased CA from from 65 deg. to 54 deg. for PEG concentration of 5%. Nevertheless, decreasing hydraulic permeability was observed after post-modification as well as during polymer blend modification. Stability examination showed that there was leaching out of modifier agent from the membrane matrix prepared via conventional PS after 10 days soaking in both water and NaOH. Reactive PS could increase the stability of the modifier agent in membrane matrix. Highlights: Black-Right-Pointing-Pointer We compared different methods to prepare low

  12. Corrosion resistance characterization of porous alumina membrane supports

    Energy Technology Data Exchange (ETDEWEB)

    Dong Yingchao, E-mail: dongyc9@mail.ustc.edu.cn [Materials and Surface Science Institute (MSSI), University of Limerick, Limerick (Ireland); USTC Lab for Solid State Chemistry and Inorganic Membranes, Department of Materials Science and Engineering, University of Science and Technology of China (USTC) (China); Key Lab of Jiangxi Universities for Inorganic Membranes, National Engineering Research Center for Domestic and Building Ceramics, Jingdezhen Ceramic University (JCU) (China); Lin Bin [USTC Lab for Solid State Chemistry and Inorganic Membranes, Department of Materials Science and Engineering, University of Science and Technology of China (USTC) (China); Zhou Jianer [Key Lab of Jiangxi Universities for Inorganic Membranes, National Engineering Research Center for Domestic and Building Ceramics, Jingdezhen Ceramic University (JCU) (China); Zhang Xiaozhen [USTC Lab for Solid State Chemistry and Inorganic Membranes, Department of Materials Science and Engineering, University of Science and Technology of China (USTC) (China); Key Lab of Jiangxi Universities for Inorganic Membranes, National Engineering Research Center for Domestic and Building Ceramics, Jingdezhen Ceramic University (JCU) (China); Ling Yihan; Liu Xingqin; Meng Guangyao [USTC Lab for Solid State Chemistry and Inorganic Membranes, Department of Materials Science and Engineering, University of Science and Technology of China (USTC) (China); Hampshire, Stuart [Materials and Surface Science Institute (MSSI), University of Limerick, Limerick (Ireland)

    2011-04-15

    Tubular porous alumina ceramic membrane supports were fabricated by an extrusion-drying-sintering process and then characterized in detail in terms of corrosion resistance in both H{sub 2}SO{sub 4} and NaOH aqueous solutions. Variations in the properties of the alumina supports such as mass loss percent, mechanical strength, open porosity and pore size distribution were studied before and after corrosion under different conditions. In addition, the microstructures were analyzed using scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction before and after corrosion. The fabricated porous alumina supports offer possibilities for some potential applications as micro-filtration or ultra-filtration membrane supports, as well as in the pre-treatment of strongly acidic industrial waste-liquids. - Research highlights: {yields} Porous alumina membrane supports fabricated by extrusion-drying-sintering process. {yields} Corrosion resistance in 20 wt.% H{sub 2}SO{sub 4} and 1, 5, 10 wt.% NaOH aqueous solutions. {yields} Rapid mass loss and loss of flexural strength occurred in hot NaOH solution. {yields} Resistant to strong acid corrosion with low mass loss, low flexural strength loss. {yields} Porous alumina supports have potential for treatment of strong acid waste liquids.

  13. Printing-assisted surface modifications of patterned ultrafiltration membranes

    International Nuclear Information System (INIS)

    Wardrip, Nathaniel C.; Dsouza, Melissa; Urgun-Demirtas, Meltem; Snyder, Seth W.

    2016-01-01

    Understanding and restricting microbial surface attachment will enhance wastewater treatment with membranes. We report a maskless lithographic patterning technique for the generation of patterned polymer coatings on ultrafiltration membranes. Polyethylene glycol, zwitterionic, or negatively charged hydrophilic polymer compositions in parallel- or perpendicular-striped patterns with respect to feed flow were evaluated using wastewater. Membrane fouling was dependent on the orientation and chemical composition of the coatings. Modifications reduced alpha diversity in the attached microbial community (Shannon indices decreased from 2.63 to 1.89) which nevertheless increased with filtration time. Sphingomonas species, which condition membrane surfaces and facilitate cellular adhesion, were depleted in all modified membranes. Microbial community structure was significantly different between control, different patterns, and different chemistries. Lastly, this study broadens the tools for surface modification of membranes with polymer coatings and for understanding and optimization of antifouling surfaces.

  14. An analysis of ultrafiltration applications for the oilsands

    Energy Technology Data Exchange (ETDEWEB)

    Pease, S. [Zenon Environmental Inc., Oakville, ON (Canada)

    2006-07-01

    This presentation examined ultrafiltration technologies in oil sands applications. The Athabasca region has limited water supplies, and regulatory standards regarding waterborne pathogens and disinfectant by-products are increasing. Membrane technologies are now rapidly replacing conventional water filtration technologies as they provide a more reliable means of filtration and use minimal amounts of chemicals. Membrane technologies are capable of removing 99.9 per cent of all Giardia, Cryptosporidium and viral agents from water samples, as well as various metals. ZeeWeed membrane filtration systems use a backpulse system to filter water in combination with a permeation system. Enhanced coagulation systems are used to remove colour, taste, and odours, as well as manganese and iron. The systems have been tested with Athabasca River samples, and are currently being used at several oil sands processing plants. It was concluded that ZeeWeed membrane systems are able to treat difficult waters with high pathogen and metals contents. tabs., figs.

  15. Modeling of Hollow-Fiber Membrane System During Ultrafiltration

    International Nuclear Information System (INIS)

    EI-Bialy, S.H.

    2004-01-01

    The present study aims to evaluate the performance of hollow fiber membrane module during ultrafiltration of aqueous solutions. The model is represented by a set of differential equations for permeate and residue pressure drop and volumetric flow rates in the axial direction, beside the principle equations of both solvent and solute fluxes through the membrane, while osmotic pressure was neglected in model equations. The shell and tube module type was considered where feed pass in the shell and permeate in the bore side. Tortousily factor of membrane pores in addition to concentration polarization modulus were taken into account in calculations. The model was solved numerically with the help of suitable program in both co current and countercurrent flow pattern and comparison of results were carried out

  16. The Use of Fiberglass and Ceramic Cylinders to Support the Root Pass in C-Steel Welds with a Double-V Groove

    Directory of Open Access Journals (Sweden)

    Ricardo Fernandes Gurgel

    2015-09-01

    Full Text Available Abstract The aim of this work is to evaluate the effectiveness of fiberglass and ceramic fiber cylinders as root-pass weld backing for a double-V groove in 16 mm-thick carbon steel. Three different cylinder diameters were tested: 4.8, 9.5 mm (fiberglass and 6.4 mm (ceramic fiber. The welding process used was GMAW. The welding technique and the following process variables were investigated: root opening, current and travel speed. The results show that cylindrical fiberglass and ceramic fiber backings not only have excellent refractory properties, but also seal the root opening and contain the weld pool sufficiently to produce a root bead free of discontinuities and with a satisfactory shape and geometry. Working points were defined, together with a possible operating range for the welding parameters. It was concluded that cylindrical fiberglass and ceramic fiber weld backings hold great promise for use in root-pass welds in double-V grooves in applications in the naval and metallurgical industry.

  17. Ceramic membrane in production of recycled water; Keraamikalvo uusioveden valmistuksessa - EKT 05

    Energy Technology Data Exchange (ETDEWEB)

    Laitinen, N; Luonsi, A; Levaenen, E; Maentylae, T; Vilen, J [Haemeen ympaeristoekeskus, Tampere (Finland)

    1999-12-31

    Applicability of ceramic ultrafiltration membrane modifications were studied with laboratory units to purify clear filtrate and biologically treated combined wastewater from high quality board manufacturing process for reuse. Also performance of polymeric membrane and ceramic membrane was compared. The performance of the membrane filtration cell, developed according to requirements of the fixed dimensions of ceramic membrane was compared with the performance of the cross-rotational commercial test unit (CR-filter) of polymeric membranes. The quality of ultrafiltration permeate, namely suspended solids, turbidity and colour, was better than the quality of lake water used in the mill. The permeate fluxes were in the range of 60-75 l/m{sup 2}h. The fouling layer primarily controlled the flux and the retention, leaving the effects of surface modifications as the secondary function. The flux was slightly higher with the biologically treated wastewater. Differences in membrane material and pore size had an effect on the cleaning ability of the membranes. The polymeric membrane and the membrane with smaller pore size were easier to clean. Tests with the CR-filter showed that the rotor increases shear forces, reduces the filtration resistance and thus increases the flux compared to the cell for ceramic membranes where the increase of shear forces can be done by increasing the flow velocities. (orig.)

  18. Ceramic membrane in production of recycled water; Keraamikalvo uusioveden valmistuksessa - EKT 05

    Energy Technology Data Exchange (ETDEWEB)

    Laitinen, N.; Luonsi, A.; Levaenen, E.; Maentylae, T.; Vilen, J. [Haemeen ympaeristoekeskus, Tampere (Finland)

    1998-12-31

    Applicability of ceramic ultrafiltration membrane modifications were studied with laboratory units to purify clear filtrate and biologically treated combined wastewater from high quality board manufacturing process for reuse. Also performance of polymeric membrane and ceramic membrane was compared. The performance of the membrane filtration cell, developed according to requirements of the fixed dimensions of ceramic membrane was compared with the performance of the cross-rotational commercial test unit (CR-filter) of polymeric membranes. The quality of ultrafiltration permeate, namely suspended solids, turbidity and colour, was better than the quality of lake water used in the mill. The permeate fluxes were in the range of 60-75 l/m{sup 2}h. The fouling layer primarily controlled the flux and the retention, leaving the effects of surface modifications as the secondary function. The flux was slightly higher with the biologically treated wastewater. Differences in membrane material and pore size had an effect on the cleaning ability of the membranes. The polymeric membrane and the membrane with smaller pore size were easier to clean. Tests with the CR-filter showed that the rotor increases shear forces, reduces the filtration resistance and thus increases the flux compared to the cell for ceramic membranes where the increase of shear forces can be done by increasing the flow velocities. (orig.)

  19. Ceramic technology for Advanced Heat Engines Project

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, D.R.

    1991-07-01

    Significant accomplishments in fabricating ceramic components for advanced heat engine programs have provided evidence that the operation of ceramic parts in high-temperature engine environments is feasible. However, these programs have also demonstrated that additional research is needed in materials and processing development, design methodology, and database and life prediction before industry will have a sufficient technology base from which to produce reliable cost-effective ceramic engine components commercially. An assessment of needs was completed, and a five year project plan was developed with extensive input from private industry. The project approach includes determining the mechanisms controlling reliability, improving processes for fabricating existing ceramics, developing new materials with increased reliability, and testing these materials in simulated engine environments to confirm reliability. Although this is a generic materials project, the focus is on the structural ceramics for advanced gas turbine and diesel engines, ceramic bearings and attachments, and ceramic coatings for thermal barrier and wear applications in these engines. To facilitate the rapid transfer of this technology to US industry, the major portion of the work is being done in the ceramic industry, with technological support from government laboratories, other industrial laboratories, and universities. This project is managed by ORNL for the Office of Transportation Technologies, Office of Transportation Materials, and is closely coordinated with complementary ceramics tasks funded by other DOE offices, NASA, DOD, and industry.

  20. Ceramic Technology For Advanced Heat Engines Project

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-01

    Significant accomplishments in fabricating ceramic components for the Department of Energy (DOE), National Aeronautics and Space Administration (NASA), and Department of Defense (DoD) advanced heat engine programs have provided evidence that the operation of ceramic parts in high-temperature engine environments is feasible. However, these programs have also demonstrated that additional research is needed in materials and processing development, design methodology, and data base and life prediction before industry will have a sufficient technology base from which to produce reliable cost-effective ceramic engine components commercially. The objective of the project is to develop the industrial technology base required for reliable ceramics for application in advanced automotive heat engines. The project approach includes determining the mechanisms controlling reliability, improving processes for fabricating existing ceramics, developing new materials with increased reliability, and testing these materials in simulated engine environments to confirm reliability. Although this is a generic materials project, the focus is on the structural ceramics for advanced gas turbine and diesel engines, ceramic bearings and attachments, and ceramic coatings for thermal barrier and wear applications in these engines. This advanced materials technology is being developed in parallel and close coordination with the ongoing DOE and industry proof of concept engine development programs. To facilitate the rapid transfer of this technology to U.S. industry, the major portion of the work is being done in the ceramic industry, with technological support from government laboratories, other industrial laboratories, and universities. Abstracts prepared for appropriate papers.

  1. OXYGEN TRANSPORT CERAMIC MEMBRANES

    International Nuclear Information System (INIS)

    Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

    2001-01-01

    Conversion of natural gas to liquid fuels and chemicals is a major goal for the Nation as it enters the 21st Century. Technically robust and economically viable processes are needed to capture the value of the vast reserves of natural gas on Alaska's North Slope, and wean the Nation from dependence on foreign petroleum sources. Technologies that are emerging to fulfill this need are all based syngas as an intermediate. Syngas (a mixture of hydrogen and carbon monoxide) is a fundamental building block from which chemicals and fuels can be derived. Lower cost syngas translates directly into more cost-competitive fuels and chemicals. The currently practiced commercial technology for making syngas is either steam methane reforming (SMR) or a two-step process involving cryogenic oxygen separation followed by natural gas partial oxidation (POX). These high-energy, capital-intensive processes do not always produce syngas at a cost that makes its derivatives competitive with current petroleum-based fuels and chemicals. This project has the following 6 main tasks: Task 1--Design, fabricate and evaluate ceramic to metal seals based on graded ceramic powder/metal braze joints. Task 2--Evaluate the effect of defect configuration on ceramic membrane conductivity and long term chemical and structural stability. Task 3--Determine materials mechanical properties under conditions of high temperatures and reactive atmospheres. Task 4--Evaluate phase stability and thermal expansion of candidate perovskite membranes and develop techniques to support these materials on porous metal structures. Task 5--Assess the microstructure of membrane materials to evaluate the effects of vacancy-impurity association, defect clusters, and vacancy-dopant association on the membrane performance and stability. Task 6--Measure kinetics of oxygen uptake and transport in ceramic membrane materials under commercially relevant conditions using isotope labeling techniques

  2. Microfiltration and ultrafiltration as a post-treatment of biogas plant digestates for producing concentrated fertilizers

    DEFF Research Database (Denmark)

    Camilleri Rumbau, Maria Salud; Norddahl, Birgir; Wei, Jiang

    2015-01-01

    Biogas plant digestate liquid fractions can be concentrated by microfiltration and ultrafiltration. Two types of microfiltration membranes (polysulphone (PS) and surface-modified polyvinylidene fluoride (PVDF)) were used to process digestate liquid fractions, and to assess their applicability in ...

  3. Drinking water treatment by ultrafiltration membranes; Potabilizacion de aguas mediante membranas de ultrafiltracion

    Energy Technology Data Exchange (ETDEWEB)

    Rojas, J. C.; Moreno, B.; Poyatos, J. M.; Rua, A. de la; Perez, J. J.; Plaza, F.; Garralon, G.; Gomez, M. A.

    2007-07-01

    In this paper the application of ultrafiltration technology as a drinking water treatment was evaluated. For this reason, a pilot scale ultrafiltration module equipped with a flat membrane cassette of polyvinylidene fluoride (PVDF) with an average pore size of 0.05 {mu}m was used. Different types of artificially polluted waters (with urban waste water and soil suspension) were used. the performance of ultrafiltration technology was evaluated by means of different physicochemical and microbiological parameters both feed water and treated water. Bacterial and viral indicators were efficiently retained by the system and the same time organoleptic parameters were improved. However, it is important to emphasize the problems that the ultrafiltration technology has for the eliminate dissolves compounds remaining the most dissolve organic compounds in the feed water. (Author) 11 refs.

  4. Stirred cell ultrafiltration of lignin from black liquor generated from South African kraft mills

    CSIR Research Space (South Africa)

    Kekana, Paul

    2016-12-01

    Full Text Available Ultrafiltration of lignin from black liquor was carried out in a stirred batch cell using polyethersulfone membranes. Parameters such as operating pressure, feed concentration, stirring rate and membrane cut-off size were varied and their effects...

  5. Comparison of ultrafiltration and dissolved air flotation efficiencies in industrial units during the papermaking process

    OpenAIRE

    Monte Lara, Concepción; Ordóñez Sanz, Ruth; Hermosilla Redondo, Daphne; Sánchez González, Mónica; Blanco Suárez, Ángeles

    2011-01-01

    The efficiency of an ultrafiltration unit has been studied and compared with a dissolved air flotation system to get water with a suited quality to be reused in the process. The study was done at a paper mill producing light weight coated paper and newsprint paper from 100% recovered paper. Efficiency was analysed by removal of turbidity, cationic demand, total and dissolved chemical oxygen demand, hardness, sulphates and microstickies. Moreover, the performance of the ultrafiltration unit an...

  6. Making equipment to process paddy water for providing drinking water by using Ozone-UVC& Ultrafiltration

    Science.gov (United States)

    Styani, E.; Dja'var, N.; Irawan, C.; Hanafi

    2018-01-01

    This study focuses on making equipment which is useful to process paddy water to be consumable as drinking water by using ozone-UVC and ultrafiltration. The equipment which is made by the process of ozone-UVC and ultrafiltration or reverse osmosis is driven by electric power generated from solar panels. In the experiment, reverse osmosis system with ozone-UVC reactor proves to be good enough in producing high quality drinking water.

  7. Glass Ceramic Formulation Data Package

    International Nuclear Information System (INIS)

    Crum, Jarrod V.; Rodriguez, Carmen P.; McCloy, John S.; Vienna, John D.; Chung, Chul-Woo

    2012-01-01

    A glass ceramic waste form is being developed for treatment of secondary waste streams generated by aqueous reprocessing of commercial used nuclear fuel (Crum et al. 2012b). The waste stream contains a mixture of transition metals, alkali, alkaline earths, and lanthanides, several of which exceed the solubility limits of a single phase borosilicate glass (Crum et al. 2009; Caurant et al. 2007). A multi-phase glass ceramic waste form allows incorporation of insoluble components of the waste by designed crystallization into durable heat tolerant phases. The glass ceramic formulation and processing targets the formation of the following three stable crystalline phases: (1) powellite (XMoO4) where X can be (Ca, Sr, Ba, and/or Ln), (2) oxyapatite Yx,Z(10-x)Si6O26 where Y is alkaline earth, Z is Ln, and (3) lanthanide borosilicate (Ln5BSi2O13). These three phases incorporate the waste components that are above the solubility limit of a single-phase borosilicate glass. The glass ceramic is designed to be a single phase melt, just like a borosilicate glass, and then crystallize upon slow cooling to form the targeted phases. The slow cooling schedule is based on the centerline cooling profile of a 2 foot diameter canister such as the Hanford High-Level Waste canister. Up to this point, crucible testing has been used for glass ceramic development, with cold crucible induction melter (CCIM) targeted as the ultimate processing technology for the waste form. Idaho National Laboratory (INL) will conduct a scaled CCIM test in FY2012 with a glass ceramic to demonstrate the processing behavior. This Data Package documents the laboratory studies of the glass ceramic composition to support the CCIM test. Pacific Northwest National Laboratory (PNNL) measured melt viscosity, electrical conductivity, and crystallization behavior upon cooling to identify a processing window (temperature range) for melter operation and cooling profiles necessary to crystallize the targeted phases in the

  8. Evaluation of the ICET Test Stand to Assess the Performance of a Range of Ceramic Media Filter Elements in Support of ASME AG-1 Subsection FO

    Energy Technology Data Exchange (ETDEWEB)

    Schemmel, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-04-26

    High Efficiency Particulate Air (HEPA) filters are defined as extended-medium, dry-type filters with: (1) a minimum particle removal efficiency of no less than 99.97 percent for 0.3 micrometer particles, (2) a maximum, clean resistance of 1.0 inch water column (in. WC) when operated at 1,000 cubic feet per minute (CFM), and (3) a rigid casing that extends the full depth of the medium. Specifically, ceramic media HEPA filters provide better performance at elevated temperatures, are moisture resistant and nonflammable, can perform their function if wetted and exposed to greater pressures, and can be cleaned and reused. This paper describes the modification and design of a large scale test stand which properly evaluates the filtration characteristics of a range of ceramic media filters challenged with a nuclear aerosol agent in order to develop Section FO of ASME AG-1.

  9. The Enhancement of the Selectivity of Complex Reactions by a Catalytic Membrane Reactor -Ethylene Oxidation Over a Ag Catalyst Supported in a Ceramic Membrane-

    OpenAIRE

    馮, 臨; 小林, 正義; Lin, FENG; Masayoshi, KOBAYASHI

    1991-01-01

    This research demonstrated that, using a membrane reactor consisting of a tubular, microporous, glass-ceramic membrane, it is possible to achieve selective oxidation of ethylene to ethylene oxide with an Ag catalyst. In experiments which a reaction temperature range of 115 to 300℃ and a contact time of 1.5 to 5 seconds, resulting data illustrated the following characteristics of this membrane reactor : 1) compared with a classic tubular reactor, the selectivity of ethylene oxide is increased ...

  10. A fractographic study of clinically retrieved zirconia–ceramic and metal–ceramic fixed dental prostheses

    Science.gov (United States)

    Pang, Zhen; Chughtai, Asima; Sailer, Irena; Zhang, Yu

    2015-01-01

    Objectives A recent 3-year randomized controlled trial (RCT) of tooth supported three- to five-unit zirconia–ceramic and metal–ceramic posterior fixed dental prostheses (FDPs) revealed that veneer chipping and fracture in zirconia–ceramic systems occurred more frequently than those in metal–ceramic systems [1]. This study seeks to elucidate the underlying mechanisms responsible for the fracture phenomena observed in this RCT using a descriptive fractographic analysis. Methods Vinyl-polysiloxane impressions of 12 zirconia–ceramic and 6 metal–ceramic FDPs with veneer fractures were taken from the patients at the end of a mean observation of 40.3 ± 2.8 months. Epoxy replicas were produced from these impressions [1]. All replicas were gold coated, and inspected under the optical microscope and scanning electron microscope (SEM) for descriptive fractography. Results Among the 12 zirconia–ceramic FDPs, 2 had small chippings, 9 had large chippings, and 1 exhibited delamination. Out of 6 metal–ceramic FDPs, 5 had small chippings and 1 had large chipping. Descriptive fractographic analysis based on SEM observations revealed that fracture initiated from the wear facet at the occlusal surface in all cases, irrespective of the type of restoration. Significance Zirconia–ceramic and metal–ceramic FDPs all fractured from microcracks that emanated from occlusal wear facets. The relatively low fracture toughness and high residual tensile stress in porcelain veneer of zirconia restorations may contribute to the higher chipping rate and larger chip size in zirconia–ceramic FDPs relative to their metal–ceramic counterparts. The low veneer/core interfacial fracture energy of porcelain-veneered zirconia may result in the occurrence of delamination in zirconia–ceramic FDPs. PMID:26233469

  11. FY2015 ceramic fuels development annual highlights

    Energy Technology Data Exchange (ETDEWEB)

    Mcclellan, Kenneth James [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

    2015-09-22

    Key challenges for the Advanced Fuels Campaign are the development of fuel technologies to enable major increases in fuel performance (safety, reliability, power and burnup) beyond current technologies, and development of characterization methods and predictive fuel performance models to enable more efficient development and licensing of advanced fuels. Ceramic fuel development activities for fiscal year 2015 fell within the areas of 1) National and International Technical Integration, 2) Advanced Accident Tolerant Ceramic Fuel Development, 3) Advanced Techniques and Reference Materials Development, and 4) Fabrication of Enriched Ceramic Fuels. High uranium density fuels were the focus of the ceramic fuels efforts. Accomplishments for FY15 primarily reflect the prioritization of identification and assessment of new ceramic fuels for light water reactors which have enhanced accident tolerance while also maintaining or improving normal operation performance, and exploration of advanced post irradiation examination techniques which will support more efficient testing and qualification of new fuel systems.

  12. FY2016 Ceramic Fuels Development Annual Highlights

    Energy Technology Data Exchange (ETDEWEB)

    Mcclellan, Kenneth James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-01-24

    Key challenges for the Advanced Fuels Campaign are the development of fuel technologies to enable major increases in fuel performance (safety, reliability, power and burnup) beyond current technologies, and development of characterization methods and predictive fuel performance models to enable more efficient development and licensing of advanced fuels. Ceramic fuel development activities for fiscal year 2016 fell within the areas of 1) National and International Technical Integration, 2) Advanced Accident Tolerant Ceramic Fuel Development, 3) Advanced Techniques and Reference Materials Development, and 4) Fabrication of Enriched Ceramic Fuels. High uranium density fuels were the focus of the ceramic fuels efforts. Accomplishments for FY16 primarily reflect the prioritization of identification and assessment of new ceramic fuels for light water reactors which have enhanced accident tolerance while also maintaining or improving normal operation performance, and exploration of advanced post irradiation examination techniques which will support more efficient testing and qualification of new fuel systems.

  13. Synthesis of crystalline ceramics for actinide immobilisation

    International Nuclear Information System (INIS)

    Burakov, B.; Gribova, V.; Kitsay, A.; Ojovan, M.; Hyatt, N.C.; Stennett, M.C.

    2007-01-01

    Methods for the synthesis of ceramic wasteforms for the immobilization of actinides are common to those for non-radioactive ceramics: hot uniaxial pressing (HUP); hot isostatic pressing (HIP); cold pressing followed by sintering; melting (for some specific ceramics, such as garnet/perovskite composites). Synthesis of ceramics doped with radionuclides is characterized with some important considerations: all the radionuclides should be incorporated into crystalline structure of durable host-phases in the form of solid solutions and no separate phases of radionuclides should be present in the matrix of final ceramic wasteform; all procedures of starting precursor preparation and ceramic synthesis should follow safety requirements of nuclear industry. Synthesis methods that avoid the use of very high temperatures and pressures and are easily accomplished within the environment of a glove-box or hot cell are preferable. Knowledge transfer between the V. G. Khlopin Radium Institute (KRI, Russia) and Immobilisation Science Laboratory (ISL, UK) was facilitated in the framework of a joint project supported by UK Royal Society. In order to introduce methods of precursor preparation and ceramic synthesis we selected well-known procedures readily deployable in radiochemical processing plants. We accounted that training should include main types of ceramic wasteforms which are currently discussed for industrial applications. (authors)

  14. Synthesis and characterization of biomorphic ceramics

    International Nuclear Information System (INIS)

    Rambo, Carlos Renato

    2001-01-01

    Biotemplating represents a recently developed technology for manufacturing of biomorphous ceramics from naturally grown plant structures. This approach allows the production of ceramic materials with cellular structure, where the microstructural features of the ceramic product are similar to the native plant. After processing, the biomorphic ceramic exhibits directed pore morphology in the micrometer range. Biomorphic SiC fibers were produced from bamboo by carbothermal reduction of SiO 2 originally present in the bamboo structure. Bamboo pieces were heated up to 1500 deg C in argon to promote the reaction between carbon and silica. Biomorphic alumina, mullite and zirconia ceramics were manufactured via the sol-gel route by repeated infiltration of low viscous oxide precursors (sols) into rattan, pine and bamboo structures. The raw samples were pyrolyzed at 800 deg C in nitrogen for 1h and subsequently annealed at 1550 deg C in air. The microstructure and physical properties of the biomorphic ceramics were characterized by X-ray diffraction (XRD) and high temperature-XRD, scanning electron microscopy (SEM), porosimetry and picnometry. Thermal analysis (TGA/DTA) was performed on the infiltrated samples in order to evaluate the reactions and the total weight loss during the thermal process. The mechanical properties were evaluated by compressive strength tests. In contrast to conventional processed ceramic foam of similar porosity, the microstructure highly porous biomorphic ceramics shows uniaxial pore morphology with anisotropic properties. These properties are favorable for applications in catalyst support, filters or low-density heat insulation structures, or as biomaterials. (author)

  15. High Concentration Protein Ultrafiltration: a Comparative Fouling Assessment

    Science.gov (United States)

    Lim, Y. P.; Mohammad, A. W.

    2018-05-01

    In this paper, the predominant fouling mechanism via pH manipulation in gelatin ultrafiltration (UF) at constant operating pressure was studied. Two 30 kDa molecular weight cut off (MWCO) UF membranes with different hydrophilic/hydrophobic properties were tested at solution pH near gelatin isoelectric point (IEP), pH below and above gelatin’s IEP. The resistance-in-series model was used to determine quantitatively the contribution of each filtration resistance occurred during gelatin UF. The governing fouling mechanisms were investigated using classical blocking laws. The results demonstrated that concentration polarization remain as dominant fouling resistance in gelatin UF, but exceptional case was observed at pH away from gelatin’s IEP, showing that combined reversible and irreversible fouling resistances contributed around 57% and 37%, respectively to the overall fouling resistances. Under all experimental condition tested, permeate flux decline was accurately predicted by all the models studied. Fouling profile was fitted well with “Standard Blocking”, “Intermediate Blocking” and “Cake Filtration” model for regenerated cellulose acetate (RCA) membrane and “Cake Filtration” model for polyethersulphone (PES) membrane.

  16. Summary of the ultrafiltration, reverse osmosis, and adsorbents project

    International Nuclear Information System (INIS)

    Colvin, C.M.; Roberts, R.C.; Williams, M.K.

    1983-01-01

    The design for a medium-size (40 gal/min) ultrafiltration (UF) membrane unit includes a schematic diagram, capital and operating costs, a list and discussion of the radioisotopes tested and the results achieved, operating parameters, and characteristics of the available membrane configurations. The plant design for a reverse osmosis (RO) membrane unit includes a conceptual diagram, specifications for a RO unit producing 40 gal/min of permeated product, a list of radioisotopes tested on RO units and the rejections achieved, a discussion of the principal of RO, a discussion of the upper limits of cation and anion concentrations (there are no lower limits), a discussion of membrane configurations and porosities, a discussion of factors affecting membranes, a section on calculating the membrane area needed for a particular application, and capital and operating cost calculations. The design for an ion-exchange pilot plant includes a schematic diagram; flow, resin, and column specifications; impurity limits; and operating and capital costs. A short theoretical discussion and process description are also included. The design retains flexibility so that application to a specific stream can be determined

  17. Whey protein concentration by ultrafiltration and study of functional properties

    Directory of Open Access Journals (Sweden)

    Sidiane Iltchenco

    2018-06-01

    Full Text Available ABSTRACT: This paper aim to evaluate the ultrafiltration (UF process for constituents recovery from whey. Sequences of factorial designs were performed by varying temperature (5 to 40°C and pressure (1 to 3 bar, to maximize the proteins concentration using membrane of 100kDa in dead end system. Based on the best result new experiments were performed with membrane of 50kDa and 10kDa. With the membrane of 50 the protein retention was about 3 times higher than the membrane of 100kDa. The concentrated obtained by UF membrane of 10kDa, 10°C and 2 bar in laboratory scale showed a mean protein retention of 80 %, greater protein solubility, emulsion stability and the identification of β-lactoglobulins (18.3 kDa and α-lactalbumin fractions (14.2kDa. Therefore, the use of membrane of 100 and 50kDa are became a industrially recommendable alternatives to concentration of whey proteins, and/or as a previous step to the fractionation of whey constituents using membrane ≤10kDa, aiming at future applications in different areas (food, pharmaceutical, chemical, etc..

  18. The potentialities of the complexation ultrafiltration technique for the decontamination of fission product contaminated aqueous effluents

    International Nuclear Information System (INIS)

    Thibert, V.

    1995-07-01

    Many nuclear researchers and industrial operators lay emphasis on improving the back end of the fuel cycle. A major problem concerns the liquid wastes generated by the reprocessing plant at La Hague, discharged into the sea after treatment in the Effluent Treatment Station (STE) 3), and which have become crucial matter. The activity of these wastes is well below the current legal limits, and is constantly decreasing these last years. To bring it close to zero, and ambitious goal, entails innovative new reprocessing techniques. We accordingly investigated the possibilities of complexation-ultrafiltration, a technique that uses water-soluble macromolecules to complex the target elements to be separated. We first achieved the strontium (II) separation with poly-acrylic and poly-sulfonic acids. The effects of pH and NaNO 3 concentration influence on Sr (II) complexation were studied. The Sr (II) complexation and concentration phases, followed by cation de-complexation to recover the polymer, were also taken into account. This research, combined with a potentiometric study of the polymers, offered a close understanding of the chemical systems involved, and of the operating conditions and limits of complexation-ultrafiltration. The laboratory results were also validated on a tangential ultrafiltration pilot plant. We then used complexation-ultrafiltration to treat a real effluent generated bu La Hague's STE 3 plant. This experiment demonstrated minimum 90 % decontamination of Sr (II) (with polyacrylate complexing agent), and also for 134-137 Cs (with simple ultrafiltration). The use of two polyamides allowed partial decontamination of the effluent for 60 Co and 106 Ru. This work therefore offers a global approach to complexation-ultrafiltration, from laboratory to pilot scale, on real and simulated effluents. The future of this technique relies chiefly on the ability to solve the problem of polymer recovery. In other respect, complexation-ultrafiltration clearly offers a

  19. Recovery of diverse microbes in high turbidity surface water samples using dead-end ultrafiltration.

    Science.gov (United States)

    Mull, Bonnie; Hill, Vincent R

    2012-12-01

    Dead-end ultrafiltration (DEUF) has been reported to be a simple, field-deployable technique for recovering bacteria, viruses, and parasites from large-volume water samples for water quality testing and waterborne disease investigations. While DEUF has been reported for application to water samples having relatively low turbidity, little information is available regarding recovery efficiencies for this technique when applied to sampling turbid water samples such as those commonly found in lakes and rivers. This study evaluated the effectiveness of a DEUF technique for recovering MS2 bacteriophage, enterococci, Escherichia coli, Clostridium perfringens, and Cryptosporidium parvum oocysts in surface water samples having elevated turbidity. Average recovery efficiencies for each study microbe across all turbidity ranges were: MS2 (66%), C. parvum (49%), enterococci (85%), E. coli (81%), and C. perfringens (63%). The recovery efficiencies for MS2 and C. perfringens exhibited an inversely proportional relationship with turbidity, however no significant differences in recovery were observed for C. parvum, enterococci, or E. coli. Although ultrafilter clogging was observed, the DEUF method was able to process 100-L surface water samples at each turbidity level within 60 min. This study supports the use of the DEUF method for recovering a wide array of microbes in large-volume surface water samples having medium to high turbidity. Published by Elsevier B.V.

  20. Pilot-scale ultrafiltration testing for the F and H area effluent treatment facility

    International Nuclear Information System (INIS)

    Kessler, J.L.

    1984-01-01

    An F and H Area Effluent Treatment Facility (F/H ETF) is being designed to treat low activity aqueous effluents which are produced from F and H Area daily operations. The treatment scheme for the F/H ETF will include pretreatment (pH adjustment and filtration) followed by Reverse Osmosis and/or Ion Exchange to remove dissolved species. Several alternative treatment processes are being considered for the F/H ETF. One of the alternatives in the pretreatment step is tubular Ultrafiltration (UF), using a dynamically formed zirconium oxide membrane supported on a porous stainless steel backing. Pilot-scale testing with a single membrane module (13 ft 2 area) and 200-Area effluent simulant has demonstrated that UF is a viable filtration option for the F/H ETF. UF testing at TNX has defined the operating conditions necessary for extended operation and also demonstrated excellent filtration performance (filtrate SDI 2 /day) flux and will provide excellent pretreatment for both reverse osmosis and ion exchange. 2 refs

  1. Ceramic Laser Materials

    Directory of Open Access Journals (Sweden)

    Guillermo Villalobos

    2012-02-01

    Full Text Available Ceramic laser materials have come a long way since the first demonstration of lasing in 1964. Improvements in powder synthesis and ceramic sintering as well as novel ideas have led to notable achievements. These include the first Nd:yttrium aluminum garnet (YAG ceramic laser in 1995, breaking the 1 KW mark in 2002 and then the remarkable demonstration of more than 100 KW output power from a YAG ceramic laser system in 2009. Additional developments have included highly doped microchip lasers, ultrashort pulse lasers, novel materials such as sesquioxides, fluoride ceramic lasers, selenide ceramic lasers in the 2 to 3 μm region, composite ceramic lasers for better thermal management, and single crystal lasers derived from polycrystalline ceramics. This paper highlights some of these notable achievements.

  2. Ceramic Laser Materials

    Science.gov (United States)

    Sanghera, Jasbinder; Kim, Woohong; Villalobos, Guillermo; Shaw, Brandon; Baker, Colin; Frantz, Jesse; Sadowski, Bryan; Aggarwal, Ishwar

    2012-01-01

    Ceramic laser materials have come a long way since the first demonstration of lasing in 1964. Improvements in powder synthesis and ceramic sintering as well as novel ideas have led to notable achievements. These include the first Nd:yttrium aluminum garnet (YAG) ceramic laser in 1995, breaking the 1 KW mark in 2002 and then the remarkable demonstration of more than 100 KW output power from a YAG ceramic laser system in 2009. Additional developments have included highly doped microchip lasers, ultrashort pulse lasers, novel materials such as sesquioxides, fluoride ceramic lasers, selenide ceramic lasers in the 2 to 3 μm region, composite ceramic lasers for better thermal management, and single crystal lasers derived from polycrystalline ceramics. This paper highlights some of these notable achievements. PMID:28817044

  3. Identification of the Allergenic Ingredients in Reduning Injection by Ultrafiltration and High-Performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    Fang Wang

    2016-01-01

    Full Text Available Reduning injection is a traditional Chinese medicine injection which has multiple functions such as clearing heat, dispelling wind, and detoxification. Although Reduning injection was widely utilized, reports of its allergenicity emerged one after another. However, there is little research on its allergenic substances. The aim of this study is to evaluate the sensitization of Reduning injection and explore the underlying cause of the anaphylactic reaction. The main ingredients in Reduning injection were analyzed before and after ultrafiltration. Ultrafiltrate Reduning injection, unfiltered Reduning injection, egg albumin, Tween-80, and nine effective components in Reduning injection were utilized to sensitize guinea pigs. The serum 5-hydroxytryptamine level was used to assess the sensitization effect of Reduning injection. We found a significant decrease in Tween-80 content comparing to other components in the injection after ultrafiltration. Unfiltered Reduning injection, Tween-80, chlorogenic acid, and cryptochlorogenin acid caused remarkable anaphylactoid reaction on guinea pigs while ultrafiltration Reduning resulted in a significantly lower degree of sensitization. Our results suggest that ultrafiltration could significantly reduce the sensitization of Reduning injection, which is likely due to the decrease of Tween-80. We also conjectured that the form of chlorogenic acid and cryptochlorogenin acid within the complex solution mixture may also affect the sensitizing effect.

  4. Development of new ultrafiltration techniques maintaining in-situ hydrochemical conditions for colloidal study

    International Nuclear Information System (INIS)

    Aosai, Daisuke; Yamamoto, Yuhei; Mizuno, Takashi

    2011-01-01

    Chemical state of elements in groundwater is one of the most important information for understanding behavior of elements in underground environment. Chemical state of elements controlled mainly by groundwater physico-chemical parameters. Because the change of physico-chemical parameters of groundwater, due to pressure release and oxidation during sampling, causes changes in chemical state of elements, systematic methodologies for understanding in situ chemical state is required. In this study, in order to understand chemical state of elements in groundwater, an ultrafiltration instrument for maintaining in-situ pressure and anaerobic conditions was developed. The instrument developed in this study for ultrafiltration made of passivated Stainless Used Steel (SUS) materials, was designed to keep groundwater samples maintaining in-situ pressure/anaerobic conditions. Ultrafiltration of groundwater was conducted at a borehole drilled from the 200 mbGL (meters below ground level) Sub-stage at a depth of 200 m at the Mizunami Underground Research Laboratory. Chemical analyses of groundwater were also conducted using samples filtered under both pressurized/anaerobic and atmospheric conditions and passivated SUS materials with different elapsed times after passivation. The results indicate that our ultrafiltration method is suitable for collection of filtered groundwater and passivation is an essential treatment before ultrafiltration. (author)

  5. Application of Ultrafiltration in a Paper Mill: Process Water Reuse and Membrane Fouling Analysis

    Directory of Open Access Journals (Sweden)

    Chen Chen

    2015-02-01

    Full Text Available High water consumption is a major environmental problem that the pulp and paper industry is facing. Ultrafiltration (UF can be used to remove the dissolved and colloidal substances (DCS concentrated during the recycling of white water (the process water to facilitate the reuse of white water and reduce fresh water consumption. However, membrane fouling limits the application of UF in this industry. In this study, super-clear filtrate obtained from a fine paper mill was purified with a polyethersulfone (PES ultrafiltration membrane to evaluate the reuse performance of the ultrafiltrate. The membrane foulants were characterized by scanning electron microscopy, energy-dispersive spectrophotometry, attenuated total reflection-fourier transform infrared spectroscopy, and gas chromatography-mass spectrometry. The results indicate that the retention rate of stock and the strength properties of paper increased when the ultrafiltrate was reused in the papermaking process compared to when super-clear filtrate was used. The reversible membrane foulants during ultrafiltration accounted for 85.52% of the total foulants and primarily originated from retention aids, drainage aids, and wet strength resins, while the irreversible adsorptive foulants accounted for 14.48% and mostly came from sizing agents, coating chemicals, and others. Moreover, the presence of dissolved multivalent metal ions, especially Ca2+, accelerated membrane fouling.

  6. The Effect of Cellulose Acetate Concentration from Coconut Nira on Ultrafiltration Membrane Characters

    Science.gov (United States)

    Vaulina, E.; Widyaningsih, S.; Kartika, D.; Romdoni, M. P.

    2018-04-01

    Cellulose acetate is one of material in produce ultrafiltration membrane. Many efforts have been done to produce cellulose acetate from natural product to replace commercial one. In this research, ultrafiltration membrane has been produced from coconut flower water (nira). Ultrafiltration membrane is widely used in separation processes. This research aims to determine the characteristics of ultrafiltration membrane at a various concentration of cellulose acetate. The ultrafiltration membrane is conducted by phase inversion method at various concentration of cellulose acetate. The cellulose acetate concentration was 20%, 23% and 25% (w/w) with formamide as additives. The results showed that the greater the concentration of cellulose acetate, the smaller the flux value. The highest flux was a membrane with 20% cellulose acetate concentration with water flux value 55.34 L/(m2. h). But the greater the concentration of cellulose acetate the greater the rejection. The highest rejection value was on a membrane with 25% cellulose acetate concentration of 82.82%. While from the tensile strength test and the pore size analysis, the greater the cellulose acetate concentration the greater the tensile strength and the smaller the pore size

  7. Fibrous-Ceramic/Aerogel Composite Insulating Tiles

    Science.gov (United States)

    White, Susan M.; Rasky, Daniel J.

    2004-01-01

    Fibrous-ceramic/aerogel composite tiles have been invented to afford combinations of thermal-insulation and mechanical properties superior to those attainable by making tiles of fibrous ceramics alone or aerogels alone. These lightweight tiles can be tailored to a variety of applications that range from insulating cryogenic tanks to protecting spacecraft against re-entry heating. The advantages and disadvantages of fibrous ceramics and aerogels can be summarized as follows: Tiles made of ceramic fibers are known for mechanical strength, toughness, and machinability. Fibrous ceramic tiles are highly effective as thermal insulators in a vacuum. However, undesirably, the porosity of these materials makes them permeable by gases, so that in the presence of air or other gases, convection and gas-phase conduction contribute to the effective thermal conductivity of the tiles. Other disadvantages of the porosity and permeability of fibrous ceramic tiles arise because gases (e.g., water vapor or cryogenic gases) can condense in pores. This condensation contributes to weight, and in the case of cryogenic systems, the heat of condensation undesirably adds to the heat flowing to the objects that one seeks to keep cold. Moreover, there is a risk of explosion associated with vaporization of previously condensed gas upon reheating. Aerogels offer low permeability, low density, and low thermal conductivity, but are mechanically fragile. The basic idea of the present invention is to exploit the best features of fibrous ceramic tiles and aerogels. In a composite tile according to the invention, the fibrous ceramic serves as a matrix that mechanically supports the aerogel, while the aerogel serves as a low-conductivity, low-permeability filling that closes what would otherwise be the open pores of the fibrous ceramic. Because the aerogel eliminates or at least suppresses permeation by gas, gas-phase conduction, and convection, the thermal conductivity of such a composite even at

  8. Thin stillage fractionation using ultrafiltration: resistance in series model.

    Science.gov (United States)

    Arora, Amit; Dien, Bruce S; Belyea, Ronald L; Wang, Ping; Singh, Vijay; Tumbleson, M E; Rausch, Kent D

    2009-02-01

    The corn based dry grind process is the most widely used method in the US for fuel ethanol production. Fermentation of corn to ethanol produces whole stillage after ethanol is removed by distillation. It is centrifuged to separate thin stillage from wet grains. Thin stillage contains 5-10% solids. To concentrate solids of thin stillage, it requires evaporation of large amounts of water and maintenance of evaporators. Evaporator maintenance requires excess evaporator capacity at the facility, increasing capital expenses, requiring plant slowdowns or shut downs and results in revenue losses. Membrane filtration is one method that could lead to improved value of thin stillage and may offer an alternative to evaporation. Fractionation of thin stillage using ultrafiltration was conducted to evaluate membranes as an alternative to evaporators in the ethanol industry. Two regenerated cellulose membranes with molecular weight cut offs of 10 and 100 kDa were evaluated. Total solids (suspended and soluble) contents recovered through membrane separation process were similar to those from commercial evaporators. Permeate flux decline of thin stillage using a resistance in series model was determined. Each of the four components of total resistance was evaluated experimentally. Effects of operating variables such as transmembrane pressure and temperature on permeate flux rate and resistances were determined and optimum conditions for maximum flux rates were evaluated. Model equations were developed to evaluate the resistance components that are responsible for fouling and to predict total flux decline with respect to time. Modeling results were in agreement with experimental results (R(2) > 0.98).

  9. Ultrafiltration and Nanofiltration Multilayer Membranes Based on Cellulose

    KAUST Repository

    Livazovic, Sara

    2016-06-09

    Membrane processes are considered energy-efficient for water desalination and treatment. However most membranes are based on polymers prepared from fossil petrochemical sources. The development of multilayer membranes for nanofiltration and ultrafiltration, with thin selective layers of naturally available cellulose, has been hampered by the availability of non-aggressive solvents. We propose the manufacture of cellulose membranes based on two approaches: (i) silylation, coating from solutions in tetrahydrofuran, followed by solvent evaporation and cellulose regeneration by acid treatment; (ii) casting from solution in 1-ethyl-3-methylimidazolum acetate ([C2mim]OAc), an ionic liquid, followed by phase inversion in water. In the search for less harsh, greener membrane manufacture, the combination of cellulose and ionic liquid is of high interest. Due to the abundance of OH groups and hydrophilicity, cellulose-based membranes have high permeability and low fouling tendency. Membrane fouling is one of the biggest challenges in membrane industry and technology. Accumulation and deposition of foulants onto the surface reduce membrane efficiency and requires harsh chemical cleaning, therefore increasing the cost of maintenance and replacement. In this work the resistance of cellulose 5 membranes towards model organic foulants such as Suwanee River Humic Acid (SRHA) and crude oil have been investigated. Cellulose membrane was tested in this work for oil-water (o/w) separation and exhibited practically 100 % oil rejection with good flux recovery ratio and membrane resistivity. The influence of anionic, cationic and ionic surfactant as well as pH and crude oil concentration on oil separation was investigated, giving a valuable insight in experimental and operational planning.

  10. Measurements of serum-free thyroid hormone concentrations by ultrafiltration

    International Nuclear Information System (INIS)

    Konno, Norimichi; Hagiwara, Kohji; Taguchi, Hideo; Murakami, Shigeki; Taguchi, Shizuko

    1987-01-01

    An ultrafiltration method (UF) for measuring free thyroxine (FT 4 ) and free triiodothyronine (FT 3 ) using the Diaflow YM membrane (Centricon-10) is described. The results are compared with those by equilibrium dialysis (ED) and also by mathematical calculations derived from T 4 , T 3 , and binding protein concentrations. The precision with the UF method was excellent. The normal ranges of FT 4 and FT 3 by the three methods are all comparable. There was a high degree of correlation of FT 4 or FT 3 results by UF with those by ED and by calculation (r = 0.940 - 0.974, n = 161, P 4 and FT 3 by all methods agreed well for hyperthyroidism, hypothyroidism, and for patients with low T 4 -binding globulin. The mean FT 3 in pregnancy was lower than the normal value for all methods, and FT 4 concentrations by UF and calculation also decreased in late pregnancy. The mean FT 4 by UF and ED in low T 3 syndrome were significantly higher than in the normal controls, while the calculated FT 4 was lower. The FT 3 in low T 3 syndrome distributed normal to subnormal in all methods. These results indicate that a) the UF method is a reliable reference method for measuring FT 4 and FT 3 concentrations; b) the UF results agree well with those by ED and also with theoretically derived values in subjects with thyroid diseases and TBG abnormalities; c) for patients with low T 3 syndrome, the FT 4 results obtained by UF and ED are similarly discrepant from the calculated results, implying the existence of binding inhibitor(s) which affect both UF and ED measurements. (author)

  11. Ceramic capacitor exhibiting graceful failure by self-clearing, method for fabricating self-clearing capacitor

    Science.gov (United States)

    Kaufman, David Y [Chicago, IL; Saha, Sanjib [Santa Clara, CA

    2006-08-29

    A short-resistant capacitor comprises an electrically conductive planar support substrate having a first thickness, a ceramic film deposited over the support substrate, thereby defining a ceramic surface; and a metallic film deposited over the ceramic surface, said film having a second thickness which is less than the first thickness and which is between 0.01 and 0.1 microns.

  12. Tensile properties of open cell ceramic foams

    Czech Academy of Sciences Publication Activity Database

    Bertolla, Luca; Dlouhý, Ivo; Řehořek, Lukáš; Chlup, Zdeněk

    2013-01-01

    Roč. 3, č. 1 (2013), s. 106-113 ISSN 1338-1660. [FRACTOGRAPHY 2012. Stará Lesná, 21.10.2012-24.10.2012] R&D Projects: GA ČR(CZ) GA101/09/1821 EU Projects: European Commission(XE) 264526 - GLACERCO Institutional support: RVO:68081723 Keywords : tension test * cellular materials * ceramics Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass

  13. Combining electrophoresis with detection under ultraviolet light and multiple ultrafiltration for isolation of humic fluorescence fractions.

    Science.gov (United States)

    Trubetskaya, Olga E; Shaloiko, Lubov A; Demin, Dmitrii V; Marchenkov, Victor V; Proskuryakov, Ivan I; Coelho, Christian; Trubetskoj, Oleg A

    2011-04-01

    Polyacrylamide gel electrophoresis of chernozem soil humic acids (HAs) followed by observation under UV (312 nm) excitation light reveals new low molecular weight (MW) fluorescent fractions. Ultrafiltration of HAs sample in 7 M urea on a membrane of low nominal MW retention (NMWR, 5 kDa) was repetitively used for separation of fluorescent and non-fluorescent species. Thirty ultrafiltrates and the final retentate R were obtained. Fluorescence maxima of separate ultrafiltrates were different and non-monotonously changed in the range of 475-505 nm. Fluorescence maxima of less than 490 nm were detected only in the four first utrafiltrates. For further physical-chemical analyses all utrafiltrates were combined into a fraction called UFchernozem soil HAs complex. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Characterization and utilization of the permeate and retentate obtained after “dead-end” ultrafiltration

    Directory of Open Access Journals (Sweden)

    Vasić Vesna M.

    2013-01-01

    Full Text Available In the recent years, with the increase in bioethanol production, the increasing amounts of distillery wastewater are generated. Such wastewater (stillage is one of the most polluted waste product of the food and beverage industries. The present study evaluates the treatment of distillery wastewater by ultrafiltration (UF, in order to reduce its pollution and evaluate the composition of the permeate and retentate. Polyethersulfone ultrafiltration membrane with molecular weight cut-off (MWCO 30000 Da, was used for the experiments. The UF was carried out in dead-end mode. The results of the analyses of the permeate and retentate obtained after ultrafiltration were considered as well as different ways for their further utilization. The pollutant level in the permeate was decreased significantly in comparison to the raw stillage, and suspended solids were completely removed from the stillage. [Projekat Ministarstva nauke Republike Srbije, br. TR 31002

  15. [Ultrafiltration versus intravenous diuretics in decompensated heart failure: a meta-analysis of randomized controlled trials].

    Science.gov (United States)

    Zhao, Yu-liang; Zhang, Ling; Yang, Ying-ying; Tang, Yi; Liu, Fang; Fu, Ping

    2013-08-13

    To explore whether ultrafiltration is superior to intravenous diuretics in ameliorating fluid overload and preserving renal functions in decompensated heart failure patients. By searching in Pubmed, Cochrane Library, Embase, Springer, WanFang, CQVIP, CNKI and CBM database as well as related Chinese journals, qualified randomized controlled trials (RCTs) were included for meta-analysis by Revman 5.0 and STATA 10.0. Six RCTs were included with 241 patients in ultrafiltration group and 240 patients in intravenous diuretics group. Pooled analyses demonstrated ultrafiltration was superior to intravenous diuretics in the aspects of weight loss (WMD = 1.44 kg, 95%CI:0.33-2.55 kg, P = 0.01) and fluid removal (WMD = 1.23 kg, 95%CI:0.63-1.82 kg, P diuretics in mitigating fluid overload. No intergroup difference was observed in renal function preservation, mortality or rehospitalization.

  16. Separation of racemic mixture by ultrafiltration of enantioselective micelles. 1 Effect of pH on separation and regeneration

    NARCIS (Netherlands)

    Overdevest, P.E.M.; Bruin, de T.J.M.; Riet, van 't K.; Keurentjes, J.T.F.; Padt, van der A.

    2001-01-01

    Many enantiomer separation systems are studied to meet the increasing demand for enantiopure compounds. One way to obtain pure enantiomers is to apply enantioselective micelles in ultrafiltration systems. We have studied the separation of phenylalanine (Phe) enantiomers by the ultrafiltration of

  17. Creep in ceramics

    CERN Document Server

    Pelleg, Joshua

    2017-01-01

    This textbook is one of its kind, since there are no other books on Creep in Ceramics. The book consist of two parts: A and B. In part A general knowledge of creep in ceramics is considered, while part B specifies creep in technologically important ceramics. Part B covers creep in oxide ceramics, carnides and nitrides. While covering all relevant information regarding raw materials and characterization of creep in ceramics, the book also summarizes most recent innovations and developments in this field as a result of extensive literature search.

  18. Ceramic Parts for Turbines

    Science.gov (United States)

    Jones, R. D.; Carpenter, Harry W.; Tellier, Jim; Rollins, Clark; Stormo, Jerry

    1987-01-01

    Abilities of ceramics to serve as turbine blades, stator vanes, and other elements in hot-gas flow of rocket engines discussed in report. Ceramics prime candidates, because of resistance to heat, low density, and tolerance of hostile environments. Ceramics considered in report are silicon nitride, silicon carbide, and new generation of such ceramic composites as transformation-toughened zirconia and alumina and particulate- or whisker-reinforced matrices. Report predicts properly designed ceramic components viable in advanced high-temperature rocket engines and recommends future work.

  19. Forming of superplastic ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Lesuer, D.R.; Wadsworth, J.; Nieh, T.G.

    1994-05-01

    Superplasticity in ceramics has now advanced to the stage that technologically viable superplastic deformation processing can be performed. In this paper, examples of superplastic forming and diffusion bonding of ceramic components are given. Recent work in biaxial gas-pressure forming of several ceramics is provided. These include yttria-stabilized, tetragonal zirconia (YTZP), a 20% alumina/YTZP composite, and silicon. In addition, the concurrent superplastic forming and diffusion bonding of a hybrid ceramic-metal structure are presented. These forming processes offer technological advantages of greater dimensional control and increased variety and complexity of shapes than is possible with conventional ceramic shaping technology.

  20. Ceramic gas turbine shroud

    Science.gov (United States)

    Shi, Jun; Green, Kevin E.

    2014-07-22

    An example gas turbine engine shroud includes a first annular ceramic wall having an inner side for resisting high temperature turbine engine gasses and an outer side with a plurality of radial slots. A second annular metallic wall is positioned radially outwardly of and enclosing the first annular ceramic wall and has a plurality of tabs in communication with the slot of the first annular ceramic wall. The tabs of the second annular metallic wall and slots of the first annular ceramic wall are in communication such that the first annular ceramic wall and second annular metallic wall are affixed.

  1. Thin film ceramic thermocouples

    Science.gov (United States)

    Gregory, Otto (Inventor); Fralick, Gustave (Inventor); Wrbanek, John (Inventor); You, Tao (Inventor)

    2011-01-01

    A thin film ceramic thermocouple (10) having two ceramic thermocouple (12, 14) that are in contact with each other in at least on point to form a junction, and wherein each element was prepared in a different oxygen/nitrogen/argon plasma. Since each element is prepared under different plasma conditions, they have different electrical conductivity and different charge carrier concentration. The thin film thermocouple (10) can be transparent. A versatile ceramic sensor system having an RTD heat flux sensor can be combined with a thermocouple and a strain sensor to yield a multifunctional ceramic sensor array. The transparent ceramic temperature sensor that could ultimately be used for calibration of optical sensors.

  2. Treatment of simulated plutonium-containing wastewater by ultrafiltration-reverse osmosis technology

    International Nuclear Information System (INIS)

    Xiong Zhonghua; Fan Xianhua; Luo Deli; Wang Tuo; Chen Qi

    2008-01-01

    Ultrafiltration and reverse osmosis were employed for the treatment of low level radioactive water containing plutonium. The system consists of ultrafiltration module with hollow fibre membrane and reverse osmosis module with spiral membrane. The decontamination efficiency and volume concentration ratio affected by technical parameters were explored in the experiment. The results show that the decontamination efficiency achieves 99.94% and the volume concentration ratio achieves 12.5 at pH=10 for solution fed into the membrane separation system. This technology will be applied in radioactive waste minimization as a new treatment method. (authors)

  3. The rapid determination of americium curium, and uranium in urine by ultrafiltration

    International Nuclear Information System (INIS)

    Stradling, G.N.; Popplewell, D.S.; Ham, G.J.; Griffin, R.

    1975-01-01

    The rapid ultrafiltration method developed for the assay of plutonium has been extended to the determination of americium, curium and uranium in urine. The limits of detection for americium and curium, and uranium are 0.09 and 0.12 dm -1 l -1 respectively, and the analysis time excluding counting less than 2 hours. The method can therefor be effectively used as a rapid screening procedure. When the reference level for plutonium is exceeded, the α activity may require to be characterised. The single ultrafiltration technique must be modified for turbid urine samples. The method is inappropriate, except for uranium, when the urine contains DTPA. (author)

  4. Decolourisations and biodegradations of model azo dye solutions using a sequence batch reactor, followed by ultrafiltration

    DEFF Research Database (Denmark)

    Korenak, J.; Ploder, J.; Trček, J.

    2018-01-01

    RNA gene and ITS1-5.8S rDNA-ITS2 sequence analysis, respectively. Serratia marcescens and Klebsiella oxytoca were the most common bacteria with the highest number present during the aerobic and anaerobic phases of the bioprocess. In addition, a high number of Elizabethkingia miricola, Morganella morganii......, Comamonas testosteroni, Trichosporon sp. and Galactomyces sp. were detected. Taken together, our results demonstrated that the sequencing batch reactor system combined with ultrafiltration is an efficient technique for treatment of wastewater containing azo dye. Moreover, the ultrafiltration effectively...

  5. Composite metal foil and ceramic fabric materials

    Science.gov (United States)

    Webb, Brent J.; Antoniak, Zen I.; Prater, John T.; DeSteese, John G.

    1992-01-01

    The invention comprises new materials useful in a wide variety of terrestrial and space applications. In one aspect, the invention comprises a flexible cloth-like material comprising a layer of flexible woven ceramic fabric bonded with a layer of metallic foil. In another aspect, the invention includes a flexible fluid impermeable barrier comprising a flexible woven ceramic fabric layer having metal wire woven therein. A metallic foil layer is incontinuously welded to the woven metal wire. In yet another aspect, the invention includes a material comprising a layer of flexible woven ceramic fabric bonded with a layer of an organic polymer. In still another aspect, the invention includes a rigid fabric structure comprising a flexible woven ceramic fabric and a resinous support material which has been hardened as the direct result of exposure to ultraviolet light. Inventive methods for producing such material are also disclosed.

  6. Predicting optimal back-shock times in ultrafiltration hollow fibre modules through path-lines

    DEFF Research Database (Denmark)

    Vinther, Frank; Pinelo, Manuel; Brøns, Morten

    2014-01-01

    This paper presents a two dimensional mathematical model of back-shocking in ultrafiltration. The model investigates the effect of back-shocking on concentration polarization. The model shows a positive effect on both the volumetric flux and the observed rejection when back-shocking is applied as...

  7. Mass transfer in corrugated-plate membrane modules. II. Ultrafiltration experiments

    NARCIS (Netherlands)

    van der Waal, M.J.; Stevanovic, S.; Racz, I.G.

    1989-01-01

    The application of corrugations as turbulence promoters in membrane filtration was studied. In ultrafiltration experiments with polysulfone membranes using Dextran T70 as solute, it was found that the corrugations result in reduced energy consumption or pressure drop compared with flat membranes at

  8. Removal of copper ions from aqueous solutions by means of micellar-enhanced ultrafiltration

    Directory of Open Access Journals (Sweden)

    Kowalska Izabela

    2017-01-01

    Full Text Available The aim of the study was to assess the usefulness of micellar–enhanced ultrafiltration (MEUF for removal of copper ions from water solutions in comparison with classic ultrafiltration process. The tests were conducted in a semi–pilot membrane installation with the use of ultrafiltration module KOCH/ROMICON® at a transmembrane pressure of 0.05 MPa. The effect of concentration of copper ions on ultrafiltration process efficiency was investigated. The second part of the tests concerned the removal of copper ions by MEUF under wide range of anionic surfactant concentration (0.25, 1, and 5 CMC (critical micelle concentration. Concentration of copper ions in model solutions was equal to 5, 20, and 50 mg Cu/L. Furthermore, the effect of surfactant leakage to the permeate side during filtration was evaluated. Conducted experiments confirmed effectiveness of MEUF in copper ions removal. For the highest copper concentration in the feed (i.e. 50 mg/L, the average concentration of copper ions in the permeate ranged from 1.2–4.7 mg Cu/L depending on surfactant concentration. During filtration experiments, UF module exhibited stable transport properties for model solutions containing copper. For the highest concentration of metal, the decrease of permeate flux did not exceed 11% after 60 minutes of filtration. In the presence of the surfactant, a slight deterioration of transport properties was observed.

  9. The effect of protein-protein and protein-membrane interactions on membrane fouling in ultrafiltration

    NARCIS (Netherlands)

    Huisman, I.H.; Prádanos, P.; Hernández, A.

    2000-01-01

    It was studied how protein-protein and protein-membrane interactions influence the filtration performance during the ultrafiltration of protein solutions over polymeric membranes. This was done by measuring flux, streaming potential, and protein transmission during filtration of bovine serum albumin

  10. A New Concept of Ultrafiltration Fouling Control : Backwashing with Low Ionic Strength Water

    NARCIS (Netherlands)

    Li, S.

    2011-01-01

    Ultrafiltration (UF) is a proven technology in water treatment nowadays. However, fouling remains a major challenge in the operation of UF, especially in regard to colloidal NOM fouling. In general, a number of colloidal NOM fouling mechanisms may occur, such as adsorption, gel formation. Colloidal

  11. Effect of high and low ultrafiltration volume during hemodialysis on relative blood volume

    NARCIS (Netherlands)

    Dasselaar, JJ; de Jong, PE; Huisman, RM; Franssen, CFM

    2006-01-01

    Achieving an optimal posthemodialysis hydration status may be difficult because objective criteria for dry weight are lacking. Both relative blood volume changes (Delta RBV) at the end of hemodialysis and Delta RBV normalized for ultrafiltration volume (Delta RBV/UF ratio) have been reported to

  12. The difference in causes of early and late ultrafiltration failure in peritoneal dialysis

    NARCIS (Netherlands)

    Smit, Watske; Parikova, Alena; Struijk, Dirk G.; Krediet, Raymond T.

    2005-01-01

    OBJECTIVE: Ultrafiltration failure (UFF) is a major complication of peritoneal dialysis. Although it seems associated with long-term treatment, it can also occur in recently started patients. To identify the causes of this complication in patients with early and late UFF we studied a group of 48

  13. Flux limitation in ultrafiltration: Osmotic pressure model and gel layer model

    NARCIS (Netherlands)

    Wijmans, J.G.; Nakao, S.; Smolders, C.A.

    1984-01-01

    The characteristic permeate flux behaviour in ultrafiltration, i.e., the existence of a limiting flux which is independent of applied pressure and membrane resistance and a linear plot of the limiting flux versus the logarithm of the feed concentration, is explained by the osmotic pressure model. In

  14. Ultrafiltration of protein solutions; the role of protein association in rejection and osmotic pressure

    NARCIS (Netherlands)

    van den Berg, G.B.; Hanemaaijer, J.H.; Smolders, C.A.

    1987-01-01

    The monomer-dimer equilibrium of the protein β-lactoglobulin under neutral conditions appears to influence the rejection and the osmotic pressure build-up, both phenomena closely related to ultrafiltration. Rejection measurements indicate different rejections for the β-lactoglobulin monomers and

  15. Optimisation of ultrafiltration of a highly viscous protein solution using spiral-wound modules

    DEFF Research Database (Denmark)

    Lipnizki, Jens; Casani, S.; Jonsson, Gunnar Eigil

    2005-01-01

    The ultrafiltration process of highly viscous protein process water with spiral-wound modules was optimised by analysing the fouling and developing a strategy to reduce it. It was shown that the flux reduction during filtration is mainly caused by the adsorption of proteins on the membrane and no...

  16. Slow ultrafiltration for continuous in vivo sampling : application for glucose and lactate in man

    NARCIS (Netherlands)

    Tiessen, RG; Kaptein, WA; Venema, K; Korf, J

    1999-01-01

    Background: An ultrafiltration (UF) technique was developed for continuous subcutaneous (s.c.) sampling and on-line analysis of absolute glucose and lactate concentrations in tissue. The relation between subcutaneous and blood concentrations was studied in men, because a subcutaneous monitoring

  17. Purification of Drug Loaded PLGA Nanoparticles Prepared by Emulsification Solvent Evaporation Using Stirred Cell Ultrafiltration Technique.

    Science.gov (United States)

    Paswan, Suresh K; Saini, T R

    2017-12-01

    The emulsifiers in an exceedingly higher level are used in the preparation of drug loaded polymeric nanoparticles prepared by emulsification solvent evaporation method. This creates great problem to the formulator due to their serious toxicities when it is to be administered by parenteral route. The final product is therefore required to be freed from the used surfactants by the conventional purification techniques which is a cumbersome job. The solvent resistant stirred cell ultrafiltration unit (Millipore) was used in this study using polyethersulfone ultrafiltration membrane (Biomax®) having pore size of NMWL 300 KDa as the membrane filter. The purification efficiency of this technique was compared with the conventional centrifugation technique. The flow rate of ultrafiltration was optimized for removal of surfactant (polyvinyl alcohol) impurities to the acceptable levels in 1-3.5 h from the nanoparticle dispersion of tamoxifen prepared by emulsification solvent evaporation method. The present investigations demonstrate the application of solvent resistant stirred cell ultrafiltration technique for removal of toxic impurities of surfactant (PVA) from the polymeric drug nanoparticles (tamoxifen) prepared by emulsification solvent evaporation method. This technique offers added benefit of producing more concentrated nanoparticles dispersion without causing significant particle size growth which is observed in other purification techniques, e.g., centrifugation and ultracentrifugation.

  18. Non-aqueous retention measurement: ultrafiltration behaviour of polystyrene solutions and colloidal silver particles

    NARCIS (Netherlands)

    Beerlage, M.A.M.; Beerlage, M.A.M.; Heijnen, M.L.; Mulder, M.H.V.; Smolders, C.A.; Smolders, C.A.; Strathmann, H.

    1996-01-01

    The retention behaviour of polyimide ultrafiltration membranes was investigated using dilute solutions of polystyrene in ethyl acetate as test solutions. It is shown that flow-induced deformation of the polystyrene chains highly affects the membrane retention. This coil-stretch transition is not

  19. Analysis of ultrafiltration failure in peritoneal dialysis patients by means of standard peritoneal permeability analysis

    NARCIS (Netherlands)

    Ho-Dac-Pannekeet, M. M.; Atasever, B.; Struijk, D. G.; Krediet, R. T.

    1997-01-01

    BACKGROUND: Ultrafiltration failure (UFF) is a complication of peritoneal dialysis (PD) treatment that occurs especially in long-term patients. Etiological factors include a large effective peritoneal surface area [measured as high mass transfer area coefficient (MTAC) of creatinine], a high

  20. Icodextrin with nitroprusside increases ultrafiltration and peritoneal transport during long CAPD dwells

    NARCIS (Netherlands)

    Douma, C. E.; Hiralall, J. K.; de Waart, D. R.; Struijk, D. G.; Krediet, R. T.

    1998-01-01

    Addition of the nitric oxide (NO) donor nitroprusside to 1.36% glucose dialysate enlarges the effective peritoneal surface area during four-hour dwells. The theoretical positive effect on ultrafiltration is, however, counteracted by an increase in glucose absorption. The absorption of the glucose

  1. Crossflow ultrafiltration of raw municipal wastewater : Investigations using PVDF tubular membranes

    NARCIS (Netherlands)

    Ravazzini, A.M.

    2008-01-01

    In the usual wastewater treatment schemes the application of membranes follows a biological process. However, ultrafiltration of untreated wastewater produces permeate free of particles and bacteria in one single step and could represent the starting point for new water-reuse concepts. This thesis

  2. Increasing Water System Efficiency with Ultrafiltration Pre-treatment in Power Plants

    International Nuclear Information System (INIS)

    Majamaa, Katariina; Suarez, Javier; Gasia Eduard

    2012-09-01

    Water demineralization with reverse osmosis (RO) membranes has a long and successful history in water treatment for power plants. As the industry strives for more efficient, reliable and compact water systems, pressurized hollow-fiber ultrafiltration (UF) has become an increasingly appealing pre-treatment technology. Compared to conventional, non- membrane based pretreatments, ultrafiltration offers higher efficiency in the removal of suspended solids, microorganisms and colloidal matter, which are all common causes for operational challenges experienced in the RO systems. In addition, UF is more capable of handling varying feed water qualities and removes the risk of particle carry-over often seen with conventional filtration techniques. Ultrafiltration is a suitable treatment technology for various water types from surface waters to wastewater, and the more fluctuating or challenging the feed water source is, the better the benefits of UF are seen compared to conventional pretreatments. Regardless of the feed water type, ultrafiltration sustains a constant supply of high quality feed water to downstream RO, allowing a more compact and cost efficient RO system design with improved operational reliability. A detailed focus on the design and operational aspects and experiences of two plants is provided. These examples demonstrate both economical UF operation and tangible impact of RO process improvement. Experience from these plants can be leveraged to new projects. (authors)

  3. Hemorrhagic iliopsoas bursitis complicating well-functioning ceramic-on-ceramic total hip arthroplasty.

    Science.gov (United States)

    Park, Kyung Soon; Diwanji, Sanket R; Kim, Hyung Keun; Song, Eun Kyoo; Yoon, Taek Rim

    2009-08-01

    Iliopsoas bursitis has been increasingly recognized as a complication of total hip arthroplasty and is usually associated with polyethylene wear. Here, the authors report a case of hemorrhagic iliopsoas bursitis complicating an otherwise well-functioning ceramic-on-ceramic arthroplasty performed by minimal invasive modified 2-incision technique. The bursitis in turn resulted in femoral nerve palsy and femoral vein compression. In this report, there was no evidence to support that the bursitis was due to an inflammatory response to ceramic wear particles or any other wear particles originating from the total hip arthroplasty.

  4. Analyses of fine paste ceramics

    International Nuclear Information System (INIS)

    Sabloff, J.A.

    1980-01-01

    Four chapters are included: history of Brookhaven fine paste ceramics project, chemical and mathematical procedures employed in Mayan fine paste ceramics project, and compositional and archaeological perspectives on the Mayan fine paste ceramics

  5. Science and Technology of Ceramics

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 5; Issue 2. Science and Technology of Ceramics - Advanced Ceramics: Structural Ceramics and Glasses. Sheela K Ramasesha. Series Article Volume 5 Issue 2 February 2000 pp 4-11 ...

  6. Analyses of fine paste ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Sabloff, J A [ed.

    1980-01-01

    Four chapters are included: history of Brookhaven fine paste ceramics project, chemical and mathematical procedures employed in Mayan fine paste ceramics project, and compositional and archaeological perspectives on the Mayan fine paste ceramics. (DLC)

  7. [Ceramic inlays and onlays].

    Science.gov (United States)

    van Pelt, A W; de Kloet, H J; van der Kuy, P

    1996-11-01

    Large direct composite restorations can induce shrinkage related postoperative sensitivity. Indirect resin-bonded (tooth colored) restorations may perhaps prevent these complaints. Indirect bonded ceramics are especially attractive because of their biocompatibility and esthetic performance. Several procedures and techniques are currently available for the fabrication of ceramic restorations: firing, casting, heat-pressing and milling. In this article the different systems are described. Advantages, disadvantages and clinical performance of ceramic inlays are compared and discussed.

  8. Ceramic Electron Multiplier

    International Nuclear Information System (INIS)

    Comby, G.

    1996-01-01

    The Ceramic Electron Multipliers (CEM) is a compact, robust, linear and fast multi-channel electron multiplier. The Multi Layer Ceramic Technique (MLCT) allows to build metallic dynodes inside a compact ceramic block. The activation of the metallic dynodes enhances their secondary electron emission (SEE). The CEM can be used in multi-channel photomultipliers, multi-channel light intensifiers, ion detection, spectroscopy, analysis of time of flight events, particle detection or Cherenkov imaging detectors. (auth)

  9. Displacive Transformation in Ceramics

    Science.gov (United States)

    1994-02-28

    PZT ), ceramics have attracted natural abundance. much attention for use in nonvolatile semiconductor mem- We attribute the observed spectra in Fig. I to...near a crack tip in piezoelectric ceramics of lead zirconate titanate ( PZT ) and barium titanate. They reasoned that the poling of ferroelectric... Texture in Ferroelastic Tetragonal Zirconia," J. Am. Ceram . Soc., 73 (1990) no. 6: 1777-1779. 27. J. F. Jue and A. Virkar, "Fabrication, Microstructural

  10. Continuous Fiber Ceramic Composites

    Energy Technology Data Exchange (ETDEWEB)

    Fareed, Ali [Honeywell Advanced Composites Inc. (HACI), Newark, DE (United States); Craig, Phillip A. [Honeywell Advanced Composites Inc. (HACI), Newark, DE (United States)

    2002-09-01

    Fiber-reinforced ceramic composites demonstrate the high-temperature stability of ceramics--with an increased fracture toughness resulting from the fiber reinforcement of the composite. The material optimization performed under the continuous fiber ceramic composites (CFCC) included a series of systematic optimizations. The overall goals were to define the processing window, to increase the robustinous of the process, to increase process yield while reducing costs, and to define the complexity of parts that could be fabricated.

  11. Piezo-electrostrictive ceramics

    International Nuclear Information System (INIS)

    Kim, Ho Gi; Shin, Byeong Cheol

    1991-09-01

    This book deals with principle and the case of application of piezo-electrostrictive ceramics, which includes definition of piezoelectric materials and production and development of piezoelectric materials, coexistence of Pb(zr, Ti)O 3 ceramics on cause of coexistence in MPB PZT ceramics, electrostrictive effect of oxide type perovskite, practical piezo-electrostrictive materials, and breaking strength, evaluation technique of piezoelectric characteristic, and piezoelectric accelerometer sensor like printer head, ink jet and piezoelectric relay.

  12. Ceramic applications in the advanced Stirling automotive engine

    Science.gov (United States)

    Tomazic, W. A.; Cairelli, J. E.

    1978-01-01

    The requirements of the ideal Stirling cycle, as well as basic types of practical engines are described. Advantages, disadvantages, and problem areas of these Stirling engines are discussed. The potential for ceramic components is also considered. Currently ceramics are used in only two areas, the air preheater and insulating tiles between the burner and the heater head. For the advanced Stirling engine to achieve high efficiency and low cost, the principal components are expected to be made from ceramic materials, including the heater head, air preheater, regenerator, the burner and the power piston. Supporting research and technology programs for ceramic component development are briefly described.

  13. Method of sintering ceramic materials

    Science.gov (United States)

    Holcombe, Cressie E.; Dykes, Norman L.

    1992-01-01

    A method for sintering ceramic materials is described. A ceramic article is coated with layers of protective coatings such as boron nitride, graphite foil, and niobium. The coated ceramic article is embedded in a container containing refractory metal oxide granules and placed within a microwave oven. The ceramic article is heated by microwave energy to a temperature sufficient to sinter the ceramic article to form a densified ceramic article having a density equal to or greater than 90% of theoretical density.

  14. Defect production in ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Zinkle, S.J. [Oak Ridge National Lab., TN (United States); Kinoshita, C. [Kyushu Univ. (Japan)

    1997-08-01

    A review is given of several important defect production and accumulation parameters for irradiated ceramics. Materials covered in this review include alumina, magnesia, spinel silicon carbide, silicon nitride, aluminum nitride and diamond. Whereas threshold displacement energies for many ceramics are known within a reasonable level of uncertainty (with notable exceptions being AIN and Si{sub 3}N{sub 4}), relatively little information exists on the equally important parameters of surviving defect fraction (defect production efficiency) and point defect migration energies for most ceramics. Very little fundamental displacement damage information is available for nitride ceramics. The role of subthreshold irradiation on defect migration and microstructural evolution is also briefly discussed.

  15. Ceramic piezoelectric materials

    International Nuclear Information System (INIS)

    Kaszuwara, W.

    2004-01-01

    Ceramic piezoelectric materials conert reversibility electric energy into mechanical energy. In the presence of electric field piezoelectric materials exhibit deformations up to 0.15% (for single crystals up to 1.7%). The deformation energy is in the range of 10 2 - 10 3 J/m 3 and working frequency can reach 10 5 Hz. Ceramic piezoelectric materials find applications in many modern disciplines such as: automatics, micromanipulation, measuring techniques, medical diagnostics and many others. Among the variety of ceramic piezoelectric materials the most important appear to be ferroelectric materials such as lead zirconate titanate so called PZT ceramics. Ceramic piezoelectric materials can be processed by methods widely applied for standard ceramics, i.e. starting from simple precursors e.g. oxides. Application of sol-gel method has also been reported. Substantial drawback for many applications of piezoelectric ceramics is their brittleness, thus much effort is currently being put in the development of piezoelectric composite materials. Other important research directions in the field of ceramic piezoelectric materials composite development of lead free materials, which can exhibit properties similar to the PZT ceramics. Among other directions one has to state processing of single crystals and materials having texture or gradient structure. (author)

  16. Corrosion of Ceramic Materials

    Science.gov (United States)

    Opila, Elizabeth J.; Jacobson, Nathan S.

    1999-01-01

    Non-oxide ceramics are promising materials for a range of high temperature applications. Selected current and future applications are listed. In all such applications, the ceramics are exposed to high temperature gases. Therefore it is critical to understand the response of these materials to their environment. The variables to be considered here include both the type of ceramic and the environment to which it is exposed. Non-oxide ceramics include borides, nitrides, and carbides. Most high temperature corrosion environments contain oxygen and hence the emphasis of this chapter will be on oxidation processes.

  17. Direct interfacial polymerization onto thin ceramic hollow fibers

    NARCIS (Netherlands)

    Maaskant, Evelien; de Wit, Patrick; Benes, Nieck E.

    2018-01-01

    Membrane separation under harsh conditions, such as high-p,T or in the presence of aggressive chemicals, requires a robust membrane support. In academia commonly ceramic disks are used for this purpose, but these disks posses a too low surface-area-to-volume ratio for practical applications. Ceramic

  18. Basic research in crystalline and noncrystalline ceramic systems. Annual report, August 1, 1980-October 31, 1981

    International Nuclear Information System (INIS)

    1981-01-01

    The Basic Research Programs in Ceramics sponsored by the US Department of Energy supports a significant fraction of the research effort and graduate student training in ceramics at MIT. Various research activities involving ceramic materials include electrical properties; kinetic studies; defect structures, defect interactions, grain boundaries and surfaces; sintering studies; and mechanical properties

  19. Physicochemical and Microbiological Properties of Yogurt-cheese Manufactured with Ultrafiltrated Cow's Milk and Soy Milk Blends

    OpenAIRE

    Lee, Na-Kyoung; Mok, Bo Ram; Jeewanthi, Renda Kankanamge Chaturika; Yoon, Yoh Chang; Paik, Hyun-Dong

    2015-01-01

    The objective of this study was to develop yogurt-cheese using cow?s milk, ultrafiltrated cow?s milk, and soy milk. The addition of soy milk and ultrafiltrated milk increased the amount of protein in the yogurt-cheese. Yogurt-cheeses were made using cheese base using 10% and 20% soy milk with raw and ultrafiltrated cow?s milk, and stored at 4? during 2 wk. The yield of yogurt-cheeses made with added soy milk was decreased and the cutting point was delayed compared to yogurt-cheese made withou...

  20. PREFACE: 3rd International Congress on Ceramics (ICC3)

    Science.gov (United States)

    Niihara, Koichi; Ohji, Tatsuki; Sakka, Yoshio

    2011-10-01

    Early in 2005, the American Ceramic Society, the European Ceramic Society and the Ceramic Society of Japan announced a collaborative effort to provide leadership for the global ceramics community that would facilitate the use of ceramic and glass materials. That effort resulted in an agreement to organize a new biennial series of the International Congress on Ceramics, convened by the International Ceramic Federation (ICF). In order to share ideas and visions of the future for ceramic and glass materials, the 1st International Congress on Ceramics (ICC1) was held in Canada, 2006, under the organization of the American Ceramic Society, and the 2nd Congress (ICC2) was held in Italy, 2008, hosted by the European Ceramic Society. Organized by the Ceramic Society of Japan, the 3rd Congress (ICC3) was held in Osaka, Japan, 14-18 November 2010. Incorporating the 23rd Fall Meeting of the Ceramic Society of Japan and the 20th Iketani Conference, ICC3 was also co-organized by the Iketani Science and Technology Foundation, and was endorsed and supported by ICF, Asia-Oceania Ceramic Federation (AOCF) as well as many other organizations. Following the style of the previous two successful Congresses, the program was designed to advance ceramic and glass technologies to the next generation through discussion of the most recent advances and future perspectives, and to engage the worldwide ceramics community in a collective effort to expand the use of these materials in both conventional as well as new and exciting applications. ICC3 consisted of 22 voluntarily organized symposia in the most topical and essential themes of ceramic and glass materials, including Characterization, design and processing technologies Electro, magnetic and optical ceramics and devices Energy and environment related ceramics and systems Bio-ceramics and bio-technologies Ceramics for advanced industry and safety society Innovation in traditional ceramics It also contained the Plenary Session and the

  1. New ceramic materials

    International Nuclear Information System (INIS)

    Moreno, R.; Dominguez-Rodriguez, A.

    2010-01-01

    This article is to provide a new ceramic materials in which, with a control of their processing and thus their microstructural properties, you can get ceramic approaching ever closer to a metal, both in its structural behavior at low as at high temperatures. (Author) 30 refs.

  2. Ceramic heat exchanger

    Science.gov (United States)

    LaHaye, Paul G.; Rahman, Faress H.; Lebeau, Thomas P. E.; Severin, Barbara K.

    1998-01-01

    A tube containment system. The tube containment system does not significantly reduce heat transfer through the tube wall. The contained tube is internally pressurized, and is formed from a ceramic material having high strength, high thermal conductivity, and good thermal shock resistance. The tube containment system includes at least one ceramic fiber braid material disposed about the internally pressurized tube. The material is disposed about the tube in a predetermined axial spacing arrangement. The ceramic fiber braid is present in an amount sufficient to contain the tube if the tube becomes fractured. The tube containment system can also include a plurality of ceramic ring-shaped structures, in contact with the outer surface of the tube, and positioned between the tube and the ceramic fiber braid material, and/or at least one transducer positioned within tube for reducing the internal volume and, therefore, the energy of any shrapnel resulting from a tube fracture.

  3. Preparation of PES ultrafiltration membranes with natural amino acids based zwitterionic antifouling surfaces

    International Nuclear Information System (INIS)

    Xu, Chen; Liu, Xiaojiu; Xie, Binbin; Yao, Chen; Hu, Wenhan; Li, Yi; Li, Xinsong

    2016-01-01

    Highlights: • Amino acids have been successfully grafted onto the surface of PES membranes via amino groups induced epoxy ring opening. • Zwitterionic PES ultrafiltration membranes exhibit excellent antifouling performance and improved permeation properties. • A facile strategy to combat fouling of PES ultrafiltration membranes is developed by grafting natural amino acids. - Abstract: In this report, a simple and facile approach to enhance the antifouling property of poly(ether sulfone) (PES) ultrafiltration membrane was developed by grafting natural amino acids onto surface. First of all, poly(ether sulfone) composite membranes blended with poly(glycidyl methacrylate) were fabricated by phase inversion method followed by grafting of different types of natural amino acids onto the membrane surface through epoxy ring opening reaction. The analysis of attenuated total reflectance Fourier transform infrared spectroscopy (ATR/FTIR) and X-ray photoelectron spectroscopy (XPS) verified the substantial enrichment of amino acids onto the surface of PES membranes. The hydrophilicity of the PES membranes was improved after grafting amino acids. The mechanical property and morphologies of the PES membranes proved that their basic performances were not obviously affected by grafting reaction, and these parameters were all still in the typical range for ultrafiltration membranes. The antifouling property of the grafted PES membranes against bovine serum albumin (BSA) and lysozyme (Lyz) was investigated in detail. It was found that PES membranes incorporated with neutral amino acids exhibited higher fouling resistance to both BSA and Lyz than the parent PES membrane. It can be ascribed to the formation of zwitterionic structure on the surface consisting of protonated secondary amino cations and carboxyl anions. Meanwhile, PES membranes grafted with charged amino acids had better antifouling properties against protein with same electric charges and improved adsorption

  4. Preparation of PES ultrafiltration membranes with natural amino acids based zwitterionic antifouling surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Chen; Liu, Xiaojiu; Xie, Binbin; Yao, Chen [School of Chemistry and Chemical Engineering, Southeast University, Nanjing, 211189 (China); Hu, Wenhan; Li, Yi [Suzhou Faith & Hope Membrane Technology Co., Ltd., Suzhou, 215000 (China); Li, Xinsong, E-mail: lixs@seu.edu.cn [School of Chemistry and Chemical Engineering, Southeast University, Nanjing, 211189 (China)

    2016-11-01

    Highlights: • Amino acids have been successfully grafted onto the surface of PES membranes via amino groups induced epoxy ring opening. • Zwitterionic PES ultrafiltration membranes exhibit excellent antifouling performance and improved permeation properties. • A facile strategy to combat fouling of PES ultrafiltration membranes is developed by grafting natural amino acids. - Abstract: In this report, a simple and facile approach to enhance the antifouling property of poly(ether sulfone) (PES) ultrafiltration membrane was developed by grafting natural amino acids onto surface. First of all, poly(ether sulfone) composite membranes blended with poly(glycidyl methacrylate) were fabricated by phase inversion method followed by grafting of different types of natural amino acids onto the membrane surface through epoxy ring opening reaction. The analysis of attenuated total reflectance Fourier transform infrared spectroscopy (ATR/FTIR) and X-ray photoelectron spectroscopy (XPS) verified the substantial enrichment of amino acids onto the surface of PES membranes. The hydrophilicity of the PES membranes was improved after grafting amino acids. The mechanical property and morphologies of the PES membranes proved that their basic performances were not obviously affected by grafting reaction, and these parameters were all still in the typical range for ultrafiltration membranes. The antifouling property of the grafted PES membranes against bovine serum albumin (BSA) and lysozyme (Lyz) was investigated in detail. It was found that PES membranes incorporated with neutral amino acids exhibited higher fouling resistance to both BSA and Lyz than the parent PES membrane. It can be ascribed to the formation of zwitterionic structure on the surface consisting of protonated secondary amino cations and carboxyl anions. Meanwhile, PES membranes grafted with charged amino acids had better antifouling properties against protein with same electric charges and improved adsorption

  5. Ultrafiltration technique in conjunction with competing ligand exchange method for Ni–humics speciation in aquatic environment

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, P.; Boissel, M.; Reuillon, A.; Babu, P.V.R.; Parthiban, G.

    The combination of ultrafiltration technique with competing ligand exchange method provides a better understanding of interactions between Ni and different molecular weight fractions of humic acid (HA) at varying pH in aquatic environment...

  6. A method for the densification of ceramic layers, especially ceramic layers within solid oxide cell (SOC) technology, and products obtained by the method

    DEFF Research Database (Denmark)

    2013-01-01

    A ceramic layer, especially for use in solid oxide cell (SOC) technology, is densified in a method comprising (a) providing a multilayer system by depositing the porous ceramic layer, which is to be densified, onto the selected system of ceramic layers on a support, (b) pre-sintering the resulting......(s) in the porous layer surface and (e) performing a thermal treatment at a temperature T2, where T2 > ?1, to obtain densification of and grain growth in the porous layer formed in step (b). The method makes it possible to obtain dense ceramic layers at temperatures, which are compatible with the other materials...... present in a ceramic multilayer system....

  7. Synthesis and characterization of ceramic-supported and metal-supported membrane layers for the separation of CO{sub 2} in fossil-fuel power plants; Herstellung und Charakterisierung von keramik- und metallgestuetzten Membranschichten fuer die CO{sub 2}-Abtrennung in fossilen Kraftwerken

    Energy Technology Data Exchange (ETDEWEB)

    Hauler, Felix

    2010-07-01

    The separation of CO{sub 2} in fossil fuel power plants has become a very important issue due to the contribution of this greenhouse gas to global warming. Thin microporous membranes are promising candidates for separating CO{sub 2} from gas flow before being exhausted into the atmosphere. The membrane demands are good permeation and separation properties and high stability under operation conditions. Novel sol-gel derived materials composed of TiO{sub 2}/ZrO{sub 2} and stabilized SiO{sub 2} seem to be promising due to their good chemical stability and microporous character, especially for the separation of H{sub 2} and CO{sub 2}. Metallic substrates should be preferred as membrane support because they exhibit practical advantages combining good mechanical stability and the benefit of facilitated joining. The present thesis deals with the development of sol-gel derived microporous membrane layers on ceramic and metallic supports for the separation of CO{sub 2}. In this context, the optimized preparation of high-quality membranes with TiO{sub 2}/ZrO{sub 2} and Ni, Co, Zr, Ti doped SiO{sub 2} top layers is presented. These multilayered membranes consist of a graded pore structure to provide a smooth transition of the pore size from the support to the functional layer. Due to the good surface properties, the ceramic substrates only need one interlayer, whereas the rough metallic substrates exhibiting larger pores require a total of three interlayers to obtain an enhanced surface quality. On both types of supports, crack-free functional layers with a thickness below 100 nm were deposited by dip-coating. The unsupported and supported sol-gel materials used for the top layers were investigated in terms of structural properties by thermal analysis, sorption measurements, X-ray diffraction and electron microscopy. Gas permeation tests with He, H{sub 2}, CO{sub 2} und N{sub 2} were carried out to determine the membrane performance with regard to permeation rates and

  8. Electrical and thermal properties of lead titanate glass ceramics

    International Nuclear Information System (INIS)

    Shankar, J.; Deshpande, V.K.

    2011-01-01

    Glass samples with composition of (50-X)PbO-(25+X)TiO 2 -25B 2 O 3 (where X=0, 5, 10 and 12.5 mol%) were prepared using conventional quenching technique. The glass transition temperature, T g and crystallization temperature T c were determined from the DTA. These glass samples were converted to glass ceramics by following two stage heat treatment schedule. The glass ceramic samples were characterized by XRD, SEM and dielectric constant measurements. The XRD results revealed the formation of ferroelectric lead titanate (PT) as a major crystalline phase in the glass ceramics. The density increases and the CTE decreases for all glass ceramics with increase in X (mol%). This may be attributed to increase in PT phase. The SEM results which show rounded crystallites of lead titanate, also supports other results. Hysteresis loops observed at room temperature confirms the ferroelectric nature of glass ceramics. The optimized glass ceramic sample exhibits high dielectric constant which is of technical importance. -- Research Highlights: →Lead titanate glass ceramics prepared by conventional quenching technique. →Lead titanate is a major crystalline phase in the glass ceramics. →The ferroelectric nature of glass ceramics is confirmed by the hysteresis study. →The high value of ε observed at room temperature is quite promising in the study.

  9. Quantification of biomolecules in herring (Clupea harengus) industry processing waters and their recovery using electroflocculation and ultrafiltration

    DEFF Research Database (Denmark)

    Osman, Ali; Gringer, Nina; Svendsen, Tore

    2015-01-01

    Four types of herring industry processing waters; refrigerated sea water (RSW), storage water (SW), processing water from cutting (PW) and pre-salting brines (SB) were subjected to chemical characterization and biomolecule recovery using electroflocculation (EF) and ultrafiltration (UF). The high......Four types of herring industry processing waters; refrigerated sea water (RSW), storage water (SW), processing water from cutting (PW) and pre-salting brines (SB) were subjected to chemical characterization and biomolecule recovery using electroflocculation (EF) and ultrafiltration (UF...

  10. Fouling reduction by ozone-enhanced backwashing process in ultrafiltration of petroleum-based oil in water emulsion

    Science.gov (United States)

    Aryanti, Nita; Prihatiningtyas, Indah; Kusworo, Tutuk Djoko

    2017-06-01

    Ultrafiltration membrane has been successfully applied for oily waste water treatment. However, one significant drawback of membrane technology is fouling which is responsible for permeate flux decline as well as reducing membrane performance. One method commonly used to reduce fouling is a backwashing process. The backwashing is carried out by a push of reversed flow from permeate side to the feed side of a membrane to remove fouling on the membrane pore and release fouling release fouling layer on the external side. However, for adsorptive fouling, the backwashing process was not effective. On the other hand, Ozone demonstrated great performance for reducing organics fouling. Hence this research was focused on backwashing process with ozone for removing fouling due to ultrafiltration of petroleum based oil emulsion. Gasoline and diesel oil were selected as dispersed phase, while as continuous phase was water added with Tween 80 as a surfactant. This research found that the Ozone backwashing was effective to improve flux recovery. In ultrafiltration of gasoline emulsion, the flux recovery after Ozone backwashing was in the range of 42-74%. For ultrafiltration of diesel oil emulsion, the permeate flux recovery was about 35-84%. In addition, foulant deposition was proposed and predicting that foulant deposition for ultrafiltration of gasoline-in-water emulsion was surfactant as the top layer and the oil was underneath the surfactant. On the other hand, for ultrafiltration of diesel oil-in-water emulsion, the oil was predicted as a top layer above the surfactant foulant.

  11. Energy rationalization in the dairy industry through the use of ultrafiltration

    Energy Technology Data Exchange (ETDEWEB)

    Faletti, L; Peri, C

    1987-02-01

    This study is one of several made by Italian universities on behalf of ENEL to razionalize the energy demand pattern of some industrial branches and identify, among the various solutions, those that might bring about primary energy saving through the use of electricity. Specifically, this study was undertaken to verify the applicability of certain diaphragm separation technologies such as ultrafiltration in Italy, and to assess their energy-efficiency in terms of primary energy. Research carried out on this subject and the industrial experience of the last years point to the possibility of using ultrafiltration in the manufacture of typical soft cheese in direct competition with conventional technologies. The expected benefits of greater yield and energy saving are of great national economic relevance, since Italy imports both the raw material (milk) and energy resources.

  12. Processing used nuclear fuel with nanoscale control of uranium and ultrafiltration

    Energy Technology Data Exchange (ETDEWEB)

    Wylie, Ernest M.; Peruski, Kathryn M.; Prizio, Sarah E. [Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, IN 46556 (United States); Bridges, Andrea N.A.; Rudisill, Tracy S.; Hobbs, David T. [Savannah River National Laboratory, Aiken, SC 29808 (United States); Phillip, William A. [Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556 (United States); Burns, Peter C., E-mail: pburns@nd.edu [Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, IN 46556 (United States); Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556 (United States)

    2016-05-15

    Current separation and purification technologies utilized in the nuclear fuel cycle rely primarily on liquid–liquid extraction and ion-exchange processes. Here, we report a laboratory-scale aqueous process that demonstrates nanoscale control for the recovery of uranium from simulated used nuclear fuel (SIMFUEL). The selective, hydrogen peroxide induced oxidative dissolution of SIMFUEL material results in the rapid assembly of persistent uranyl peroxide nanocluster species that can be separated and recovered at moderate to high yield from other process-soluble constituents using sequestration-assisted ultrafiltration. Implementation of size-selective physical processes like filtration could results in an overall simplification of nuclear fuel cycle technology, improving the environmental consequences of nuclear energy and reducing costs of processing. - Highlights: • Nanoscale control in irradiated fuel reprocessing. • Ultrafiltration to recover uranyl cage clusters. • Alternative to solvent extraction for uranium purification.

  13. More Efficient Sodium Removal by Ultrafiltration Compared to Diuretics in Acute Heart Failure; Underexplored and Overstated.

    Science.gov (United States)

    Kazory, Amir

    2016-01-01

    Enhanced removal of sodium has often been cited as an advantage of ultrafiltration (UF) therapy over diuretic-based medical treatment in the management of acute decompensated heart failure. However, so far clinical studies have rarely evaluated the precise magnitude of sodium removal, and this assumption is largely based on the physiologic mechanisms and anecdotal observations that predate the contemporary management of heart failure. Recent data suggest that patients treated with UF experience substantial reduction in urinary sodium excretion possibly due to prolonged intravascular volume contraction. Consequently, the efficient sodium extraction through production of isotonic ultrafiltrate can be offset by urine hypotonicity. Based on the limited currently available data, it seems unlikely that the persistent benefits of UF could be solely explained by its greater efficiency in sodium removal. The design of the future studies should include frequent measurements of urine sodium to precisely compare the impact of UF and diuretics on sodium balance. © 2016 S. Karger AG, Basel.

  14. Enhancing performance and surface antifouling properties of polysulfone ultrafiltration membranes with salicylate-alumoxane nanoparticles

    Science.gov (United States)

    Mokhtari, Samaneh; Rahimpour, Ahmad; Shamsabadi, Ahmad Arabi; Habibzadeh, Setareh; Soroush, Masoud

    2017-01-01

    To improve the hydrophilicity and antifouling properties of polysulfone (PS) ultrafiltration membranes, we studied the use of salicylate-alumoxane (SA) nanoparticles as a novel hydrophilic additive. The effects of SA nanoparticles on the membrane characteristics and performance were investigated in terms of membrane structure, permeation flux, solute rejection, hydrophilicity, and antifouling ability. The new mixed-matrix membranes (MMMs) possess asymmetric structures. They have smaller finger-like pores and smoother surfaces than the neat PS membranes. The embedment of SA nanoparticles in the polymer matrix and the improvement of surface hydrophilicity were investigated. Ultrafiltration experiments indicated that the pure-water flux of the new MMMs initially increases with SA nanoparticles loading followed by a decrease at high loadings. Higher BSA solution flux was achieved for the MMMs compared to the neat PS membranes. Membranes with 1 wt.% SA nanoparticles exhibit the highest flux recovery ratio of 87% and the lowest irreversible fouling of 13%.

  15. Full mouth rehabilitation with retrievable metal-ceramic implant-supported fixed prostheses for a young patient with atrophic jaws: a clinical report.

    Science.gov (United States)

    Ameri, Narges; Alikhasi, Marzieh; Rezayani, Vida

    2017-09-01

    Treatment of atrophic edentulous jaws with implant-supported fixed prostheses is one of the most complicated challenges in dentistry. This clinical report describes the prosthesis which consists of screw retained frameworks with individual cement retained crowns which combines the advantages of the screw retained restoration with the advantage of cement retained.

  16. The processing of used cooking oil (yellow grease) using combination of adsorption and ultrafiltration membrane processes

    Science.gov (United States)

    Rosnelly, C. M.; Sofyana; Amalia, D.; Sarah, S.

    2018-03-01

    Yellow grease is used cooking oil whose quality has degraded due to the oxidation, polymerization, or hydrolysis process. In previous studies, yellow grease refining had been conducted either by adsorption or by using membrane. In this study, adsorption process using adsorbent from bagasse activated with H3PO4 12.5%, and ultrafiltration using Polyethersulfone (PES) membrane were combined. In adsorption stage, several variation of bagasse mass was fed into 200 ml of yellow grease and stirred for 60 minutes at 60 rpm. Yellow grease produced from adsorption with best condition was then processed using ultrafiltration membran that is PES membran with concentration by 15 wt % with transmembrane pressure variation by 0.5; 1; 1.5; 2; and 2.5 Bar. Analysis of yellow grease characteristics before refined showed its acid number, peroxide number, iodine number, and water content respectively by 2.68 mgKOH/Kg; 5.97 Meq/Kg; 51,48; and 1.29%. Characteristics of yellow grease after adsorption at its best condition on the parameters of acid number, peroxide number, iodine number, and water content are respectively by 2.55 mgKOH/Kg; 4.19 Meq/Kg; 40,02; and 0.27%. Characteristics of yellow grease after ultrafiltration at its best condition on the parameters of acid number, peroxide number, iodine number, and water content are respectively by 1.12 mgKOH/Kg; 1.8 Meq/Kg; 41,36; and 0.02%. Combination of adsorption and ultrafiltration processes for yellow grease processing showed decreasing value on the parameters of acid number, peroxide number, and water content that conforms to the SNI quality standard, but has not been able to increase the iodine number.

  17. The use of ultrafiltration for the clean-up of alkaline Pu containing effluents

    International Nuclear Information System (INIS)

    Biddle, P.; Gutman, R.G.

    1983-07-01

    Ultrafiltration has been used to clean up low level Pu solutions at high pH. The decontamination factors achieved were greater than 1000 and were significantly higher than those attained by sedimentation or centrifugation. The results confirmed the findings of earlier work based on the use of Th as a simulant for Pu. A preliminary flowsheet for the decontamination of Pu oxalate liquors is proposed. (author)

  18. Removal of phenol from synthetic waste water using Gemini micellar-enhanced ultrafiltration (GMEUF)

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wenxiang [MOE Key Laboratory of Regional Energy and Environmental Systems Optimization, Resources and Environmental Research Academy, North China Electric Power University, Beijing 102206 (China); Huang, Guohe, E-mail: huang@iseis.org [MOE Key Laboratory of Regional Energy and Environmental Systems Optimization, Resources and Environmental Research Academy, North China Electric Power University, Beijing 102206 (China); Wei, Jia [Faculty of Engineering and Applied Science, University of Regina, Regina, Saskatchewan, Canada S4S 0A2 (Canada); Li, Huiqin; Zheng, Rubing; Zhou, Ya [MOE Key Laboratory of Regional Energy and Environmental Systems Optimization, Resources and Environmental Research Academy, North China Electric Power University, Beijing 102206 (China)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer Gemini surfactant micellar enhanced ultrafiltration was used to remove phenol. Black-Right-Pointing-Pointer The effect of different hydrophilic head groups of surfactant was analyzed. Black-Right-Pointing-Pointer SEM, ATR-FTIR and mercury porosimeter were applied to elucidate membrane fouling. Black-Right-Pointing-Pointer Gemini surfactant had superior performance in comparing with conventional surfactant. - Abstract: Comprehensive studies were conducted on the phenol wastewater ultrafiltration (UF) with the help of various concentrations of cationic Gemini surfactant (N1-dodecyl-N1,N1,N2,N2-tetramethyl-N2-octylethane-1,2-diaminium bromide, CG), conventional cationic surfactant (dodecyl trimethyl ammonium bromide, DTAB), anionic surfactant (sodium dodecyl sulfate, SDS) and nonionic surfactant ((dodecyloxy)polyethoxyethanol, Brij35). A flat sheet module with polyethersulfone (PES) membrane was employed in this investigation. The effects of feed concentration (phenol and surfactant) on the retention of phenol and surfactant, permeate flux and membrane fouling by micelles were evaluated. The distribution coefficient (D), the loading of the micelles (L{sub m}) and the equilibrium distribution constant (K) were also utilized to estimate the micellar-enhanced ultrafiltration ability for phenol. Scanning electron microscope (SEM), Fourier transform infrared spectrometer with attenuated total reflectance accessory (ATR-FTIR) and mercury porosimeter were applied to analyze membrane surface morphology, membrane material characteristics and membrane fouling for the original and fouled membranes. Based on the above analysis, the performance of the selected Gemini surfactant was proved superior in the following aspects: retention of phenol/surfactant (peak value is 95.8% for phenol retention), permeate flux and membrane fouling with respect to other conventional surfactants possessing equal alkyl chain length. These results demonstrated

  19. Hollow fiber membrane ultrafiltration of a simulated secondary treatment wastewater. Process and fouling modeling

    OpenAIRE

    Soler Cabezas, José Luis; Vincent Vela, Maria Cinta; Mendoza Roca, José Antonio; Martínez Francisco, Francisco Juan

    2012-01-01

    It is well known that there is a scarcity of drinking and irrigation water around the world nowadays. According to the United Nations, water scarcity affects 1.2 billion people (one-fifth of the world's population) and the water use has been growing at twice the rate of population increase in the last century. This fact makes the reuse of the wastewater from municipal wastewater treatment plants (MWTPs) an interesting option. Ultrafiltration after the secondary settling is becoming more f...

  20. Industrial ceramics - Properties, forming and applications

    International Nuclear Information System (INIS)

    Fantozzi, Gilbert; Niepce, Jean-Claude; Bonnefont, Guillaume; Alary, J.A.; Allard, B.; Ayral, A.; Bassat, J.M.; Elissalde, C.; Maglione, M.; Beauvy, M.; Bertrand, G.; Bignon, A.; Billieres, D.; Blanc, J.J.; Blumenfeld, P.; Bonnet, J.P.; Bougoin, M.; Bourgeon, M.; Boussuge, M.; Thorel, A.; Bruzek, C.E.; Cambier, F.; Carrerot, H.; Casabonne, J.M.; Chaix, J.M.; Chevalier, J.; Chopinet, M.H.; Couque, H.; Courtois, C.; Leriche, A.; Dhaler, D.; Denape, J.; Euzen, P.; Ganne, J.P.; Gauffinet, S.; Girard, A.; Gonon, M.; Guizard, C.; Hampshire, S.; Joulin, J.P.; Julbe, A.; Ferrato, M.; Fontaine, M.L.; Lebourgeois, R.; Lopez, J.; Maquet, M.; Marinel, S.; Marrony, M.; Martin, J.F.; Mougin, J.; Pailler, R.; Pate, M.; Petitpas, E.; Pijolat, C.; Pires-Franco, P.; Poirier, C.; Poirier, J.; Pourcel, F.; Potier, A.; Tulliani, J.M.; Viricelle, J.P.; Beauger, A.

    2013-01-01

    After a general introduction to ceramics (definition, general properties, elaboration, applications, market data), this book address conventional ceramics (elaboration, material types), thermo-structural ceramics (oxide based ceramics, non-oxide ceramics, fields of application, functional coatings), refractory ceramics, long fibre and ceramic matrix composites, carbonaceous materials, ceramics used for filtration, catalysis and the environment, ceramics for biomedical applications, ceramics for electronics and electrical engineering (for capacitors, magnetic, piezoelectric, dielectric ceramics, ceramics for hyper-frequency resonators), electrochemical ceramics, transparent ceramics (forming and sintering), glasses, mineral binders. The last chapter addresses ceramics used in the nuclear energy sector: in nuclear fuels and fissile material, absorbing ceramics and shields, in the management of nuclear wastes, new ceramics for reactors under construction or for future nuclear energy

  1. Ceramic stove eases strain on African forests | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2010-10-28

    Oct 28, 2010 ... IDRC began supporting research that led to the marketing of the ceramic Jiko stove in the ... IDRC Communications ... Informal sector workers producing the traditional stoves were sent designs and convinced to switch to this ...

  2. Alkali-bonded ceramics with hierarchical tailored porosity

    Czech Academy of Sciences Publication Activity Database

    Landi, E.; Medri, V.; Papa, E.; Dědeček, Jiří; Klein, Petr; Benito, P.; Vaccari, A.

    2013-01-01

    Roč. 73, SI (2013), s. 56-64 ISSN 0169-1317 Institutional support: RVO:61388955 Keywords : alkali-bonded ceramics * metalcaolin * geopolymerization parameters Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.703, year: 2013

  3. Decontamination by ultrafiltration of low radioactivity waste water from fuel element fabrication

    International Nuclear Information System (INIS)

    Muller, H.M.

    1984-01-01

    It could be demonstrated that waste waters which contain uranium in a filterable form, such as laundry and floor-cleaning waste, can be sufficiently decontaminated by means of ultra-filtration. In the case of process waste solutions, which contain uranium in a dissolved form, high decontamination factors could be achieved by means of flocculation or coprecipitation. The following methods were tested: - flocculation with Fe (OH) 3 , - coprecipitation with CaHPO 4 , - precipitation with K 4 (Fe(CN) 6 ). The phosphate precipitation, whereby the uranium is probably coprecipitated as Ca(UO 2 ) 2 (PO 4 ) 2 , was found to be the most reliable method. Difficulties were encountered when complex-forming anions, notably carbonate, oxalate and fluoride were present. These necessitate specific pretreatment steps. Whether ultrafiltration then still remains an economical option must be judged in each individual case. The application of the methods so far developed on combined waste streams remains an object for further research. In combination with a phosphate precipitation, ultrafiltration is a suitable method for the decontamination of low-activity, uranium-contaminated waste waters

  4. [Study on the interface of human hepatocyte/micropore polypropylene ultrafiltration membrane].

    Science.gov (United States)

    Peng, Cheng-Hong; Han, Bao-San; Gao, Chang-You; Ma, Zu-Wei; Zhao, Zhi-Ming; Wang, Yong; Liu, Hong; Zhang, Gui-di; Yang, Mei-Juan

    2004-09-02

    To found a new interface of human hepatocyte/micropore polypropylene ultrafiltration membrane (MPP) with good cytocompatibility so as to construct bioartificial bioreactor with polypropylene hollow fibers in future. MPP ultrafiltration membrane underwent chemical grafting modification through ultraviolet irradiation and Fe(2+) reduction. The contact angles of MPP and the modified MPP membranes were measured. Human hepatic cells L-02 were cultured. MPP and modified MPP membranes were spread on the wells of culture plate and human hepatic cells and cytodex 3 were inoculated on them. Different kinds of microscopy were used to observe the morphology of these cells. The water contact angle of MPP and the modified MPP membranes decreased from 78 degrees +/- 5 degrees to 27 degrees +/- 4 degrees (P < 0.05), which indicated that the hydrophilicity of the membrane was improved obviously after the grafting modification. Human hepatocyte L-02 did not adhere to and spread on the modified MPP membrane surface, and only grew on the microcarrier cytodex 3 with higher density and higher proliferation ratio measured by MTT. Grafting modification of acrylamide on MPP membrane is a good method to improve the human hepatocyte cytocompatibility with MPP ultrafiltration membrane.

  5. Enhanced starch hydrolysis using α-amylase immobilized on cellulose ultrafiltration affinity membrane.

    Science.gov (United States)

    Konovalova, Viktoriia; Guzikevich, Kateryna; Burban, Anatoliy; Kujawski, Wojciech; Jarzynka, Karolina; Kujawa, Joanna

    2016-11-05

    In order to prepare ultrafiltration membranes possessing biocatalytic properties, α-amylase has been immobilized on cellulose membranes. Enzyme immobilization was based on a covalent bonding between chitosan and a surface of cellulose membrane, followed by an attachment of Cibacron Blue F3G-A dye as affinity ligand. Various factors affecting the immobilization process, such as enzyme concentration, pH of modifying solution, zeta-potential of membrane surface, and stability of immobilized enzyme were studied. The applicability of immobilized α-amylase has been investigated in ultrafiltration processes. The immobilization of α-amylase on membrane surface allows to increase the value of mass transfer coefficient and to decrease the concentration polarization effect during ultrafiltration of starch solutions. The enzyme layer on the membrane surface prevents a rapid increase of starch concentration due to the amylase hydrolysis of starch in the boundary layer. The presented affinity immobilization technique allows also for the regeneration of membranes from inactivated enzyme. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. The in-process removal of sterol glycosides by ultrafiltration in biodiesel production

    Directory of Open Access Journals (Sweden)

    André Y. Tremblay

    2017-03-01

    Full Text Available Minor components found in biodiesel can affect its stability and cold flow properties. Without extensive post treatments, trace compounds such as sterol glycosides (SG can remain at unacceptable levels in finished biodiesel fuels. This study proposes to remove SG from reacted Fatty Acid Methyl Ester (FAME mixtures using ultrafiltration. Degummed soybean oil was transesterified using methanol and a catalyst (sodium methoxide. The mixtures were immediately ultrafiltered after the reaction and the FAMEs from the retentate and permeate were analyzed for SG. The highest separation for SG (86 % was obtained when the reaction conditions were 0.7 wt.% catalyst and 4:1 MeOH:Oil ratio. The lowest separation (0% was observed at 0.3 wt.% catalyst and 4:1 MeOH:Oil ratio. The higher separations were explained by the deprotonation of the hydroxyl groups on SG. This decreased the solubility of SG in the reacted FAME phase. The separation was lowest, when unreacted oil along with monoacylglycerides (MG and diacylglycerides (DG solubilized SG in the reacted mixture. The separation was also low when high methanol to oil ratios were used in the transesterification. The lowest concentration of SG measured in FAMEs treated by ultrafiltration was 3.4 ppm. The results indicate that ultrafiltration is an effective method to remove SG from soybean FAMEs.

  7. Improved antifouling performance of ultrafiltration membrane via preparing novel zwitterionic polyimide

    Science.gov (United States)

    Huang, Haitao; Yu, Jiayu; Guo, Hanxiang; Shen, Yibo; Yang, Fan; Wang, Han; Liu, Rong; Liu, Yang

    2018-01-01

    On the basis of the outstanding fouling resistance of zwitterionic polymers, an antifouling ultrafiltration membrane was fabricated through phase inversion induced by immersion precipitation method, directly using the novel zwitterionic polyimide (Z-PI), which was synthesized via a two-step procedure including polycondensation and quaternary amination reaction, as membrane material. The chemical structure and composition of the obtained polymer were confirmed by using FTIR, 1H NMR and XPS analysis, and its thermal stability was thoroughly characterized by TGA measurement, respectively. The introduction of zwitterionic groups into polyimide could effectively increase membrane pore size, porosity and wettability, and convert the membrane surface from hydrophobic to highly hydrophilic. As a result, Z-PI membrane displayed significantly improved water permeability compared with that of the reference polyimide (R-PI) membrane without having an obvious compromise in protein rejection. According to the static adsorption and dynamic cycle ultrafiltration experiments of bovine serum albumin (BSA) solution, Z-PI membrane exhibited better fouling resistant ability, especially irreversible fouling resistant ability, suggesting superior antifouling property and long-term performance stability. Moreover, Z-PI membrane had a water flux recovery ratio of 93.7% after three cycle of BSA solution filtration, whereas only about 68.5% was obtained for the control R-PI membrane. These findings demonstrated the advantages of Z-PI membrane material and aimed to provide a facile and scalable method for the large-scale preparation of low fouling ultrafiltration membranes for potential applications.

  8. Exploration of zwitterionic cellulose acetate antifouling ultrafiltration membrane for bovine serum albumin (BSA) separation.

    Science.gov (United States)

    Liu, Yang; Huang, Haitao; Huo, Pengfei; Gu, Jiyou

    2017-06-01

    This study focused on the preparation of a new kind of membrane material, zwitterionic cellulose acetate (ZCA), via a three-step procedure consist of oxidization, Schiff base and quaternary amination reaction, and the fabrication of antifouling ZCA ultrafiltration membrane by the non-solvent-induced phase separation method (NIPS). The morphologies, surface chemical structures and compositions of the obtained CA and ZCA membranes were thoroughly characterized by field emission scanning electron microscopy (FE-SEM) with energy dispersive X-ray (EDX) spectroscopy, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), respectively. Meanwhile, the thermal stability, porosity and average pore size of two investigated membranes were also studied. As a result, the ZCA membrane displayed significantly improved hydrophilicity and water permeability compared with those of the reference CA membrane, despite a slight decrease in the protein rejection ratio. According to the cycle ultrafiltration performance of bovine serum albumin (BSA) solution and protein adsorption experiment, ZCA membrane exhibited better flux recovery property and fouling resistant ability, especially irreversible fouling resistant ability, suggesting superior antifouling performance. This new approach gives polymer-based membrane a long time life and excellent ultrafiltration performance, and seems promising for potential applications in the protein separation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Preparation of ultrafiltration membrane by phase separation coupled with microwave irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Suryani, Puput Eka [Department of Chemical Engineering, Faculty of Engineering, Diponegoro University Jl. Prof. Soedarto, Semarang 50275, Central Java (Indonesia); Department of Chemical Engineering, Faculty of Engineering, UniversitasMuhammadiyah Surakarta Jl. Jendral Ahmad Yani, Surakarta 57102, Central Java (Indonesia); Purnama, Herry [Department of Chemical Engineering, Faculty of Engineering, UniversitasMuhammadiyah Surakarta Jl. Jendral Ahmad Yani, Surakarta 57102, Central Java (Indonesia); Susanto, Heru, E-mail: heru.susanto@undip.ac.id [Department of Chemical Engineering, Faculty of Engineering, Diponegoro University Jl. Prof. Soedarto, Semarang 50275, Central Java (Indonesia)

    2015-12-29

    Preparation of low fouling ultrafiltration membrane is still a big challenge in the membrane field. In this paper, polyether sulfone (PES) ultrafiltration membranes were prepared by non-solvent-induced phase separation (NIPS) coupled with microwave irradiation. Polyethylene glycol (PEG) and polyethylene glycol methacrylate (PEGMA) were used as additives to improve membrane hydrophilicity. In this study, the concentration of additive, irradiation time and microwave power was varied. The membranes were characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy, while the performances were tested by adsorptive and ultrafiltration fouling experiments. The results show that the irradiation time and irradiation power are very important parameter that influence the membrane characteristic. In addition, type and concentration of additive are other important parameters. The results suggest that microwave irradiation is the most important parameter influencing the membrane characteristic. Both pure water flux and fouling resistance increase with increasing irradiation time, power irradiation, and additive concentration. PES membrane with addition of 10% w/w PEG and irradiated by 130 W microwave power for 180 seconds is the best membrane performance.

  10. FLUX PROFILES AND MATHEMATICAL MODELING OF FOULING MECHANISM FOR ULTRAFILTRATION OF KONJAC GLUCOMANNAN

    Directory of Open Access Journals (Sweden)

    NITA ARYANTI

    2016-07-01

    Full Text Available This study was focused on principles and fouling analysis of konjac glucomannan (KGM separation using ultrafiltration system. Two Polyethersulfone membranes (PES having molecular weight cut-off of 10 and 20 kDa were used. It was found that membrane having larger pore size provided higher flux profiles. Evaluation of different transmembrane pressures resulted on possibility of more severe fouling at higher membrane pressure. With the increase of konjac glucomannan concentration, decrease of profile flux was observed. Further, a simple mathematical modelling of fouling mechanism was analyzed based on Hermia’s model. The images of membrane surfaces and cross-sections obtained by scanning electron microscopy (SEM were examined and being compared with the model. The research found that the fouling mechanisms of KGM ultrafiltration using membrane with pore size of 10 kDa was complete blocking. On the contrary, cake/gel layer formation was a fouling mechanism for ultrafiltration system with pore size of 20kDa.

  11. Fouling Characteristics of Dissolved Organic Matter in Papermaking Process Water on Polyethersulfone Ultrafiltration Membranes

    Directory of Open Access Journals (Sweden)

    Wenpeng Su

    2015-07-01

    Full Text Available In the papermaking industry, closure of process water (whitewater circuits has been used to reduce fresh water consumption. Membrane separation technology has potential for use in treating process water for recirculation. The purpose of this study was to reveal the fouling characteristics of a polyethersulfone (PES ultrafiltration membrane caused by dissolved organic matter (DOM in process water. Ultrafiltration membranes (UF and DAX ion exchange resins were applied to characterize the molecular weight (MW and hydrophilicity distribution of DOM. The interactions between various fractions of DOM and a PES ultrafiltration membrane were investigated. The membrane fouling characteristics were elucidated by examining the filtration resistances and linearized Herman’s blocking models. The results demonstrated that the membrane was fouled significantly by much of the MW distribution. The membrane was fouled more significantly by the low MW fraction rather than the high MW fraction. The filtration resistances and the fitted equation of Hermia’s laws indicated that hydrophilic organics were the main foulants. The hydrophilic organics partially block the membrane pores and form intermediate blocking, reducing the effective filtration area, while the hydrophobic organics form a gel layer or cake on the surface of the membrane.

  12. Increased saccharification of kallar grass using ultrafiltrated enzyme from sporrotrichum thermophile

    International Nuclear Information System (INIS)

    Latif, F.; Rajoka, M.I.; Malik, K.A.

    1991-01-01

    The local wild type strain of sporotrichum thermophile when grown on untreated lingo cellulose was found to produce a greater level of B-glucosidase component along with other cellulase/xylanase components than most of the reported wild type potent strains. Culture filtrate obtained, when grown on 4% leptochloa fusca (kallar grass) was used as such and after concentration by ultrafiltration technique for saccharification purpose. Concentrated enzymes titre was increased to 1.2 and 4.0 U/ml for Fp-ase and B-glucosidase, respectively. There were losses in the enzyme titre obtained through ultrafiltration possibly due to adsorption on to the ultrafiltration membrane. Enzyme preparations used, saccharifide 5% kallar grass to 70, 55, 75 and 60% (theoretical basis) from cellulases of S. thermophile concentrate, dilute, T. reesei alone and in supplementation with B-glucosidase from A. niger, respectively. Analysis by HPLC revealed slightly higher glucose yield from S. thermophile enzyme preparations, whereas higher level of xylose was attained from T. reesei preparations. Rest of the sugars pooled as Oligo-sugars were found in almost similar concentrations. (author)

  13. Research on the experiment of reservoir water treatment applying ultrafiltration membrane technology of different processes.

    Science.gov (United States)

    Zhang, Liyong; Zhang, Penghui; Wang, Meng; Yang, Kai; Liu, Junliang

    2016-09-01

    The processes and effects of coagulation-ultrafiltration (C-UF) and coagulation sedimentation-ultrafiltration (CS-UF) process used in the treatment of Dalangdian Reservoir water were compared. The experiment data indicated that 99% of turbidity removal and basically 100% of microorganism and algae removal were achieved in both C-UF and CS-UF process. The organic removal effect of CS-UF? process was slightly better than C-UF process. However, the organic removal effect under different processes was not obvious due to limitation of ultrafiltration membrane aperture. Polyaluminium chloride was taken as a coagulant in water plant. The aluminum ion removal result revealed that coagulant dosage was effectively saved by using membrane technology during megathermal high algae laden period. Within the range of certain reagent concentration and soaking time, air-water backwashing of every filtration cycle of membrane was conducted to effectively reduce membrane pollution. Besides, maintenance cleaning was conducted every 60 min. whether or not restorative cleaning was conducted depends on the pollution extent. After cleaning, recovery of membrane filtration effect was obvious.

  14. Treatment of olive mill wastewater by the combination of ultrafiltration and bipolar electrochemical reactor processes

    KAUST Repository

    Yahiaoui, O.

    2011-01-01

    The main purpose of this study was to investigate the removal of the chemical oxygen demand (COD) from olive mill wastewater (OMW) by the combination of ultrafiltration with electrocoagulation process. Ultrafiltration process equipped with CERAVER membrane was used as pre-treatment for electrochemical process. The obtained permeate from the ultrafiltration process allowed COD removal efficiency of about 96% from OMW. Obtained permeate with an average COD of about 1.1gdm-3 was treated by electrochemical reactor equipped with a reactor with bipolar iron plate electrodes. The effect of the experimental parameters such as current density, pH, surface electrode/reactor volume ratio and NaCl concentration on COD removal was assessed. The results showed that the optimum COD removal rate was obtained at a current density of 93.3Am-2 and pH ranging from 4.5 to 6.5. At the optimum operational parameters for the experiments, electrocoagulation process could reduce COD from 1.1gdm-3 to 78mgdm-3, allowing direct discharge of the treated OMW as that meets the Algerian wastewater discharge standards (<125mgdm-3). © 2010 Elsevier B.V.

  15. Use of waste ceramics in adsorption technologies

    Czech Academy of Sciences Publication Activity Database

    Doušová, B.; Koloušek, D.; Keppert, M.; Machovic, V.; Lhotka, M.; Urbanová, Martina; Brus, Jiří; Holcova, L.

    2016-01-01

    Roč. 134, Part 2 (2016), s. 145-152 ISSN 0169-1317 R&D Projects: GA ČR(CZ) GA13-24155S Institutional support: RVO:61389013 Keywords : waste ceramics * brick dust * toxic cations Subject RIV: JN - Civil Engineering Impact factor: 3.101, year: 2016

  16. Flame assisted synthesis of catalytic ceramic membranes

    DEFF Research Database (Denmark)

    Johansen, Johnny; Mosleh, Majid; Johannessen, Tue

    2004-01-01

    technology it is possible to make supported catalysts, composite metal oxides, catalytically active surfaces, and porous ceramic membranes. Membrane layers can be formed by using a porous substrate tube (or surface) as a nano-particle filter. The aerosol gas from the flame is led through a porous substrate...

  17. Ceramic breeder materials

    International Nuclear Information System (INIS)

    Johnson, C.E.

    1990-01-01

    The breeding blanket is a key component of the fusion reactor because it directly involves tritium breeding and energy extraction, both of which are critical to development of fusion power. The lithium ceramics continue to show promise as candidate breeder materials. This promise was recognized by the International Thermonuclear Reactor (ITER) design team in its selection of ceramics as the first option for the ITER breeder material. Blanket design studies have indicated properties in the candidate materials data base that need further investigation. Current studies are focusing on tritium release behavior at high burnup, changes in thermophysical properties with burnup, compatibility between the ceramic breeder and beryllium multiplier, and phase changes with burnup. Laboratory and in-reactor tests, some as part of an international collaboration for development of ceramic breeder materials, are underway. 32 refs., 1 fig., 1 tab

  18. Corrosion resistant ceramic materials

    Science.gov (United States)

    Kaun, T.D.

    1996-07-23

    Ceramic materials are disclosed which exhibit stability in severely-corrosive environments having high alkali-metal activity, high sulfur/sulfide activity and/or molten halides at temperatures of 200--550 C or organic salt (including SO{sub 2} and SO{sub 2}Cl{sub 2}) at temperatures of 25--200 C. These sulfide ceramics form stoichiometric (single-phase) compounds with sulfides of Ca, Li, Na, K, Al, Mg, Si, Y, La, Ce, Ga, Ba, Zr and Sr and show melting-points that are sufficiently low and have excellent wettability with many metals (Fe, Ni, Mo) to easily form metal/ceramic seals. Ceramic compositions are also formulated to adequately match thermal expansion coefficient of adjacent metal components. 1 fig.

  19. Ceramic injection molding

    International Nuclear Information System (INIS)

    Agueda, Horacio; Russo, Diego

    1988-01-01

    Interest in making complex net-shape ceramic parts with good surface finishing and sharp tolerances without machining is a driving force for studying the injection molding technique. This method consists of softhening the ceramic material by means of adding some plastic and heating in order to inject the mixture under pressure into a relatively cold mold where solidification takes place. Essentially, it is the same process used in thermoplastic industry but, in the present case, the ceramic powder load ranges between 80 to 90 wt.%. This work shows results obtained from the fabrication of pieces of different ceramic materials (alumina, barium titanate ferrites, etc.) in a small scale, using equipments developed and constructed in the laboratory. (Author) [es

  20. Applications of Piezoelectric Ceramics

    Indian Academy of Sciences (India)

    Applications of Piezoelectric Ceramics. Piezoelectric Actuators. Nano and Micropositioners. Vibration Control Systems. Computer Printers. Piezoelectric Transformers,Voltage Generators, Spark Plugs, Ultrasonic Motors,. Ultrasonic Generators and Sensors. Sonars, Medical Diagnostic. Computer Memories. NVFRAM ...

  1. Corrosion resistant ceramic materials

    Science.gov (United States)

    Kaun, Thomas D.

    1996-01-01

    Ceramic materials which exhibit stability in severely-corrosive environments having high alkali-metal activity, high sulfur/sulfide activity and/or molten halides at temperatures of 200.degree.-550.degree. C. or organic salt (including SO.sub.2 and SO.sub.2 Cl.sub.2) at temperatures of 25.degree.-200.degree. C. These sulfide ceramics form stoichiometric (single-phase) compounds with sulfides of Ca, Li, Na, K, Al, Mg, Si, Y, La, Ce, Ga, Ba, Zr and Sr and show melting-points that are sufficiently low and have excellent wettability with many metals (Fe, Ni, Mo) to easily form metal/ceramic seals. Ceramic compositions are also formulated to adequately match thermal expansion coefficient of adjacent metal components.

  2. Making Ceramic Cameras

    Science.gov (United States)

    Squibb, Matt

    2009-01-01

    This article describes how to make a clay camera. This idea of creating functional cameras from clay allows students to experience ceramics, photography, and painting all in one unit. (Contains 1 resource and 3 online resources.)

  3. Simulation and performance study of ceramic THGEM

    Science.gov (United States)

    Yan, Jia-Qing; Xie, Yu-Guang; Hu, Tao; Lu, Jun-Guang; Zhou, Li; Qu, Guo-Pu; Cai, Xiao; Niu, Shun-Li; Chen, Hai-Tao

    2015-06-01

    THGEMs based on a ceramic substrate have been successfully developed for neutron and single photon detection. The influences on thermal neutron scattering and internal radioactivity of both ceramic and FR-4 substrates were studied and compared. The ceramic THGEMs are homemade, of 200 μm hole diameter, 600 μm pitch, 200 μm thickness, 80 μm rim, and 50 mm×50 mm sensitive area. FR-4 THGEMs with the same geometry were used as a reference. The gas gain, energy resolution and gain stability were measured in different gas mixtures using 5.9 keV X-rays. The maximum gain of a single layer ceramic THGEM reaches 6×104 and 1.5×104 at Ne+CH4=95:5 and Ar + i-C4H10 = 97:3, respectively. The energy resolution is better than 24%. Good gain stability was obtained during a more than 100 hour continuous test in Ar+CO2 = 80:20. By using a 239Pu source, the alpha deposited energy spectrum and gain curve of the ceramic THGEM were measured. Supported by National Natural Science Foundation of China (11205173) and State Key Laboratory of Particle Detection and Electronics (H9294206TD)

  4. Ceramic Technology Project. Semiannual progress report, April 1991--September 1991

    Energy Technology Data Exchange (ETDEWEB)

    1992-03-01

    The Ceramic Technology Project was developed by the USDOE Office of Transportation Systems (OTS) in Conservation and Renewable Energy. This project, part of the OTS`s Materials Development Program, was developed to meet the ceramic technology requirements of the OTS`s automotive technology programs. Significant accomplishments in fabricating ceramic components for the USDOE and NASA advanced heat engine programs have provided evidence that the operation of ceramic parts in high-temperature engine environments is feasible. These programs have also demonstrated that additional research is needed in materials and processing development, design methodology, and data base and life prediction before industry will have a sufficient technology base from which to produce reliable cost-effective ceramic engine components commercially. A five-year project plan was developed with extensive input from private industry. In July 1990 the original plan was updated through the estimated completion of development in 1993. The objective is to develop the industrial technology base required for reliable ceramics for application in advanced automotive heat engines. The project approach includes determining the mechanisms controlling reliability, improving processes for fabricating existing ceramics, developing new materials with increased reliability, and testing these materials in simulated engine environments to confirm reliability. Although this is a generic materials project, the focus is on the structural ceramics for advanced gas turbine and diesel engines, ceramic bearings and attachments, and ceramic coatings for thermal barrier and wear applications in these engines. To facilitate the rapid transfer of this technology to US industry, the major portion of the work is being done in the ceramic industry, with technological support from government laboratories, other industrial laboratories, and universities.

  5. Factors affecting the electrostatic charge of ceramic powders

    International Nuclear Information System (INIS)

    Lorite, I.; Romero, J.; Fernandez, J. F.

    2011-01-01

    The phenomenon of electrostatic charge in ceramic powders takes place when the particle surfaces enter in contact between them or with the containers. The accumulation of electrostatic charge is of relevance in ceramic powders in view of their insulating character and the risk of explosions during the material handling. In this work the main factors that affect the appearance of intrinsic charge and tribo-charge in ceramic powder have been studied. In ceramic powders of alumina it has been verified that the smallest particle sizes present an increase of the electrostatic charge of negative polarity. A correlation has been observed between the nature of the OH -surface groups and the electrostatic charge. The intrinsic charge and the tribocharge in ceramic powders can be diminished by compensating the surface groups that support the charge. The dry dispersion of nanoparticles on microparticles allows surface charge compensation with a noticeable modification of the powder agglomeration. (Author) 19 refs.

  6. Performance of ceramics in ring/cylinder applications

    International Nuclear Information System (INIS)

    Dufrane, K.F.; Glaeser, W.A.

    1987-01-01

    In support of the efforts to apply ceramics to advanced heat engines, a study is being performed of the performance of ceramics at the ring/cylinder interface of advanced (low heat rejection) engines. The objective of the study, managed by the Oak Ridge National Laboratory, is to understand the basic mechanisms controlling the wear of ceramics and thereby identify means for applying ceramics effectively. Attempts to operate three different zirconias, silicon carbide, silicon nitride, and plasma-sprayed ceramic coatings without lubrication have not been successful because of excessive friction and high wear rates. Silicon carbide and silicon nitride perform well at ambient temperatures with fully formulated mineral oil lubrication, but are limited to temperatures of 500F because of the lack of suitable liquid lubricants for higher temperatures

  7. A Novel Seeding Method of Interfacial Polymerization-Assisted Dip Coating for the Preparation of Zeolite NaA Membranes on Ceramic Hollow Fiber Supports.

    Science.gov (United States)

    Cao, Yue; Wang, Ming; Xu, Zhen-Liang; Ma, Xiao-Hua; Xue, Shuang-Mei

    2016-09-28

    A novel seeding method combining interfacial polymerization (IP) technique with dip-coating operation was designed for directly coating nanosized NaA seed crystals (150 nm) onto the micrometer-sized α-Al2O3 hollow fiber support, in which the polyamide (PA) produced by IP acted as an effective medium to freeze and fix seed crystals at the proper position so that the controlled seed layer could be accomplished. While a coating suspension with only 0.5 wt % seed content was used, a very thin seed layer with high quality and good adhesion was achieved through dip coating twice without drying between, and the whole seeding process was operated at ambient conditions. The resulting zeolite NaA membranes not only exhibited high pervaporation (PV) performance with an average separation factor above 10000 and flux nearly 9.0 kg/m(2)·h in dehydration of 90 wt % ethanol aqueous solution at 348 K but also demonstrated great reproducibility by testing more than eight batches of zeolite membranes. In addition, this seeding strategy could be readily extended to the preparation of other supported zeolite membranes for a wide range of separation applications.

  8. Selecting Ceramics - Introduction

    OpenAIRE

    Cassidy, M.

    2002-01-01

    AIM OF PRESENTATION: To compare a number of materials for extracoronal restoration of teeth with particular reference to CAD-CAM ceramics. CASE DESCRIPTION AND TREATMENT CARRIED OUT: This paper will be illustrated using clinical examples of patients treated using different ceramic restorations to present the advantages and disadvantages and each technique. The different requirements of tooth preparation, impression taking and technical procedures of each system will be presented and compar...

  9. Cavitation damage of ceramics

    International Nuclear Information System (INIS)

    Kovalenko, V.I.; Marinin, V.G.

    1988-01-01

    Consideration is given to results of investigation of ceramic material damage under the effect of cavitation field on their surface, formed in water under the face of exponential concentrator, connected with ultrasonic generator UZY-3-0.4. Amplitude of vibrations of concentrator face (30+-2)x10 -6 m, frequency-21 kHz. It was established that ceramics resistance to cavitation effect correlated with the product of critical of stress intensity factor and material hardness

  10. Optimization of an enhanced ceramic micro-filter for concentrating E.coli in water

    Science.gov (United States)

    Zhang, Yushan; Guo, Tianyi; Xu, Changqing; Hong, Lingcheng

    2017-02-01

    Recently lower limit of detection (LOD) is necessary for rapid bacteria detection and analysis applications in clinical practices and daily life. A critical pre-conditioning step for these applications is bacterial concentration, especially for low level of pathogens. Sample volume can be largely reduced with an efficient pre-concentration process. Some approaches such as hollow-fiber ultra-filtration and electrokinetic technique have been applied to bacterial concentration. Since none of these methods can provide a concentrating method with a stable recovery efficiency, bacterial concentration still remains challenging Ceramic micro- filter can be used to concentrate the bacteria but the cross flow system keeps the bacteria in suspension. Similar harvesting bacteria using ultra-filtration showed an average recovery efficiency of 43% [1] and other studies achieved recovery rates greater than 50% [2]. In this study, an enhanced ceramic micro-filter with 0.14 μm pore size was proposed and demonstrated to optimize the concentration of E.coli. A high recovery rate (mean value >90%) and a high volumetric concentration ratio (>100) were achieved. Known quantities (104 to 106 CFU/ml) of E.coli cells were spiked to different amounts of phosphate buffered saline (0.1 to 1 L), and then concentrated to a final retentate of 5 ml to 10 ml. An average recovery efficiency of 95.3% with a standard deviation of 5.6% was achieved when the volumetric con- centration ratio was 10. No significant recovery rate loss was indicated when the volumetric concentration ratio reached up to 100. The effects of multiple parameters on E.coli recovery rate were also studied. The obtained results indicated that the optimized ceramic micro- filtration system can successfully concentrate E.coli cells in water with an average recovery rate of 90.8%.

  11. Manufacture of a ceramic paper for art applications

    Science.gov (United States)

    Dölle, K.; Honig, A.; Piatkowski, J.; Kuempel, C.

    2018-01-01

    Ceramic paper products are mostly used as high temperature ceramic insulation products. They offer an effective solution for most demanding heat management and insulation applications. The objective for this research project was to create a ceramic paper like product that combines the advantages of paper fibers, ceramic filler, and a clay product into one product, which can be produced on a continuous base with a paper machine. The produced ceramic paper product had a ceramic filler level between 59.68% and 78.8% with a basis weight between 322.9 g/m² and 693.7 g/m², and a final moisture content of 58.6% to 44.7% respectively. The wooden fiber served as a support medium for the ceramic filler material during production on the paper machine and during the conversion process into art pieces. During firing in a kiln, the fiber material combusted and the ceramic filler material mixture acts as common pottery clay, holding the desired shape of the art pieces produced.

  12. Large ceramics for fusion applications

    International Nuclear Information System (INIS)

    Hauth, W.E.; Stoddard, S.D.

    1979-01-01

    Prominent ceramic raw materials and products manufacturers were surveyed to determine the state of the art for alumina ceramic fabrication. This survey emphasized current capabilities and limitations for fabrication of large, high-density, high-purity, complex shapes. Some directions are suggested for future needs and development. Ceramic-to-ceramic sealing has applications for several technologies that require large and/or complex vacuum-tight ceramic shapes. Information is provided concerning the assembly of complex monolithic ceramic shapes by bonding of subassemblies at temperatures ranging from 450 to 1500 0 C. Future applications and fabrication techniques for various materials are presented

  13. Clinical application of bio ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Anu, Sharma, E-mail: issaranu@gmail.com; Gayatri, Sharma, E-mail: sharmagayatri@gmail.com [Department of Chemistry, Govt. College of Engineering & Technology, Bikaner, Rajasthan (India)

    2016-05-06

    Ceramics are the inorganic crystalline material. These are used in various field such as biomedical, electrical, electronics, aerospace, automotive and optical etc. Bio ceramics are the one of the most active areas of research. Bio ceramics are the ceramics which are biocompatible. The unique properties of bio ceramics make them an attractive option for medical applications and offer some potential advantages over other materials. During the past three decades, a number of major advances have been made in the field of bio ceramics. This review focuses on the use of these materials in variety of clinical scenarios.

  14. The history of ceramic filters.

    Science.gov (United States)

    Fujishima, S

    2000-01-01

    The history of ceramic filters is surveyed. Included is the history of piezoelectric ceramics. Ceramic filters were developed using technology similar to that of quartz crystal and electro-mechanical filters. However, the key to this development involved the theoretical analysis of vibration modes and material improvements of piezoelectric ceramics. The primary application of ceramic filters has been for consumer-market use. Accordingly, a major emphasis has involved mass production technology, leading to low-priced devices. A typical ceramic filter includes monolithic resonators and capacitors packaged in unique configurations.

  15. Clinical application of bio ceramics

    International Nuclear Information System (INIS)

    Anu, Sharma; Gayatri, Sharma

    2016-01-01

    Ceramics are the inorganic crystalline material. These are used in various field such as biomedical, electrical, electronics, aerospace, automotive and optical etc. Bio ceramics are the one of the most active areas of research. Bio ceramics are the ceramics which are biocompatible. The unique properties of bio ceramics make them an attractive option for medical applications and offer some potential advantages over other materials. During the past three decades, a number of major advances have been made in the field of bio ceramics. This review focuses on the use of these materials in variety of clinical scenarios.

  16. Alternative movement : collaborative project has researchers looking to ceramic membranes to improve produced water treatment

    Energy Technology Data Exchange (ETDEWEB)

    Wells, P.

    2009-10-15

    Ceramic membranes have high chemical and thermal stability coupled with mechanical strength and are therefore used in a range of microfiltration, ultrafiltration and nanofiltration applications. This article described a new technology that involves the use of ceramic membranes in the treatment of produced water in thermal heavy oil recovery operations. The efficacy of advanced ceramic nano-membrane technology (CMT) is being examined in bench-scale experiments at the Southern Alberta Institute of Technology (SAIT) in collaboration with the department of chemical and petroleum engineering at the University of Calgary. In one project, next-generation ceramic membrane technology is being used as part of the overall treatment process of produced water. The project is funded through a Canadian Association of Petroleum Producers fund and the Alberta Department of Energy. It is facilitated by the Petroleum Technology Alliance Canada in an effort to find cost-effective treatment solutions for recycling produced water for the conventional oil and gas industry. The key objective is to increase the amount of produced water that can be reused rather than disposed into deep saline aquifers. The research focuses on the pre-treatment of produced water and related salt impacted water by using ceramic membranes for the removal of organic compounds for beneficial reuse downstream. Ceramic membranes consist of a multilayer system and their performance depends on the separation and permeation properties of the membrane as well as its mechanical integrity. It was concluded that the CMT findings will be beneficial to the oil and gas industry in providing practical solutions for the challenging issues associated with de-oiling and produced water treatment. 2 figs.

  17. Surface modification of ceramics. Ceramics no hyomen kaishitsu

    Energy Technology Data Exchange (ETDEWEB)

    Hioki, T. (Toyota Central Research and Development Labs., Inc., Nagoya (Japan))

    1993-07-05

    Surface modification of ceramics and some study results using in implantation in surface modification are introduced. The mechanical properties (strength, fracture toughness, flaw resistance) of ceramics was improved and crack was repaired using surface modification by ion implantation. It is predicted that friction and wear properties are considerably affected because the hardness of ceramics is changed by ion implantation. Cementing and metalization are effective as methods for interface modification and the improvement of the adhesion power of the interface between metal and ceramic is their example. It was revealed that the improvement of mechanical properties of ceramics was achieved if appropriate surface modification was carried out. The market of ceramics mechanical parts is still small, therefore, the present situation is that the field of activities for surface modification of ceramics is also narrow. However, it is thought that in future, ceramics use may be promoted surely in the field like medicine and mechatronics. 8 refs., 4 figs.

  18. Effect of operating conditions on the performances of multichannel ceramic UF membranes for textile mercerization wastewater treatment.

    Science.gov (United States)

    Zebić Avdičević, Maja; Košutić, Krešimir; Dobrović, Slaven

    2017-01-01

    Textile wastewaters are rated as one of the most polluting in all industrial sectors, and membrane separation is the most promising technology for their treatment and reuse of auxiliary chemicals. This study evaluates the performance of three types of tubular ceramic ultrafiltration membranes differing by mean pore size (1, 2 and 500 kDa) treating textile mercerization wastewater from a textile mill at different operating conditions: cross-flow velocity (CFV) and temperature. Acceptable results were obtained with 1 kDa ceramic membrane, with rejection efficiencies 92% for suspended solids, 98% for turbidity, 98% for color and 53% for total organic carbon at 20°C and 3 m s -1 CFV. Highest fouling effect was observed for 500 kDa membrane and lowest CFV. According to the observed results, 1 kDa membrane could be used for the treatment of wastewater from the textile mercerization process in terms of permeate quality.

  19. FY 1999 project on the development of new industry support type international standards. Standardization of a testing/evaluation method of biological use fine ceramics; 1999 nendo shinki sangyo shiengata kokusai hyojun kaihatsu jigyo seika hokokusho. Seitaiyo fine ceramics no shiken hyoka hoho no hyojunka

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    For the purpose of standardizing/international standardizing an evaluation method of the characteristics required for biological use fine ceramics, and the FY 1999 results were summed up. In the study of characteristics of biological use fine ceramic materials, it was confirmed that zirconia ceramics are more excellent than alumina ceramics in static strength, repeated loads and fatigue properties in the atmospheric air at room temperature. In the study of the evaluation method of biological affinity, the standardization of the simulated body liquid preparation process was studied, and the simulated body liquid was prepared. To evaluate the bioactivity of biological use fine ceramics without making animal experiments, the simulated body liquid in which the ion concentration was made exactly equal to that of human being was prepared using 2-hydroxyethyl-1-piperazinyl ethane sulfonic acid as buffer. There were seen no changes in ion concentration for four weeks at longest as long as this liquid is kept in airtight container at temperature of 36.5 degrees C or below. The present situation of the standardization of bioceramics was surveyed. (NEDO)

  20. [Ceramic-on-ceramic bearings in total hip arthroplasty (THA)].

    Science.gov (United States)

    Sentürk, U; Perka, C

    2015-04-01

    The main reason for total hip arthroplasty (THA) revision is the wear-related aseptic loosening. Younger and active patients after total joint replacement create high demands, in particular, on the bearings. The progress, especially for alumina ceramic-on-ceramic bearings and mixed ceramics have solved many problems of the past and lead to good in vitro results. Modern ceramics (alumina or mixed ceramics containing alumina) are extremely hard, scratch-resistant, biocompatible, offer a low coefficient of friction, superior lubrication and have the lowest wear rates in comparison to all other bearings in THA. The disadvantage of ceramic is the risk of material failure, i.e., of ceramic fracture. The new generation of mixed ceramics (delta ceramic), has reduced the risk of head fractures to 0.03-0.05 %, but the risk for liner fractures remains unchanged at about 0.02 %. Assuming a non-impinging component implantation, ceramic-on-ceramic bearings have substantial advantages over all other bearings in THA. Due to the superior hardness, ceramic bearings produce less third body wear and are virtually impervious to damage from instruments during the implantation process. A specific complication for ceramic-on-ceramic bearings is "squeaking". The high rate of reported squeaking (0.45 to 10.7 %) highlights the importance of precise implant positioning and the stem and patient selection. With precise implant positioning this problem is rare with many implant designs and without clinical relevance. The improved tribology and the presumable resulting implant longevity make ceramic-on-ceramic the bearing of choice for young and active patients. Georg Thieme Verlag KG Stuttgart · New York.

  1. Testing method for ceramic armour and bare ceramic tiles

    NARCIS (Netherlands)

    Carton, E.P.; Roebroeks, G.H.J.J.

    2016-01-01

    TNO developed an alternative, more configuration independent ceramic test method than the Depth-of-Penetration test method. In this alternative test ceramic tiles and ceramic based armour are evaluated as target without a semi-infinite backing layer. An energy approach is chosen to evaluate and rank

  2. Testing method for ceramic armor and bare ceramic tiles

    NARCIS (Netherlands)

    Carton, E.P.; Roebroeks, G.H.J.J.

    2014-01-01

    TNO has developed an alternative, more configuration independent ceramic test method than the standard Depth-of-Penetration test method. In this test ceramic tiles and ceramic based armor are evaluated as target without a semi-infinite backing layer. An energy approach is chosen to evaluate and rank

  3. Concept of ceramics-free coaxial waveguide

    International Nuclear Information System (INIS)

    Arai, Hiroyuki

    1994-01-01

    A critical key point of the ITER IC antenna is ceramics support of an internal conductor of a coaxial antenna feeder close to the plasma, because dielectric loss tangent of ceramics enhanced due to neutron irradiation limits significantly the antenna injection power. This paper presents a ceramics-free waveguide to overcome this problem by a T-shaped ridged waveguide with arms for the mechanical support. This ridged waveguide has a low cutoff frequency for its small cross section, which has been proposed for the conceptual design study of Fusion Experimental Reactor (FER) IC system and the high frequency supplementary IC system for ITER. This paper presents the concept of ceramics-free coaxial waveguide consisting of the coaxial-line and the ridged waveguide. This paper also presents the cutoff frequency and the electric field distribution of the ridged waveguide calculated by a finite element method and an approximate method. The power handling capability more than 3 MW is evaluated by using the transmission-line theory and the optimized antenna impedance considering the ITER plasma parameters. We verify this transmission-line model by one-tenth scale models experimentally. (author)

  4. Mechanical properties of ceramics

    CERN Document Server

    Pelleg, Joshua

    2014-01-01

    This book discusses the mechanical properties of ceramics and aims to provide both a solid background for undergraduate students, as well as serving as a text to bring practicing engineers up to date with the latest developments in this topic so they can use and apply these to their actual engineering work.  Generally, ceramics are made by moistening a mixture of clays, casting it into desired shapes and then firing it to a high temperature, a process known as 'vitrification'. The relatively late development of metallurgy was contingent on the availability of ceramics and the know-how to mold them into the appropriate forms. Because of the characteristics of ceramics, they offer great advantages over metals in specific applications in which hardness, wear resistance and chemical stability at high temperatures are essential. Clearly, modern ceramics manufacturing has come a long way from the early clay-processing fabrication method, and the last two decades have seen the development of sophisticated technique...

  5. Fatigue of dental ceramics.

    Science.gov (United States)

    Zhang, Yu; Sailer, Irena; Lawn, Brian R

    2013-12-01

    Clinical data on survival rates reveal that all-ceramic dental prostheses are susceptible to fracture from repetitive occlusal loading. The objective of this review is to examine the underlying mechanisms of fatigue in current and future dental ceramics. The nature of various fatigue modes is elucidated using fracture test data on ceramic layer specimens from the dental and biomechanics literature. Failure modes can change over a lifetime, depending on restoration geometry, loading conditions and material properties. Modes that operate in single-cycle loading may be dominated by alternative modes in multi-cycle loading. While post-mortem examination of failed prostheses can determine the sources of certain fractures, the evolution of these fractures en route to failure remains poorly understood. Whereas it is commonly held that loss of load-bearing capacity of dental ceramics in repetitive loading is attributable to chemically assisted 'slow crack growth' in the presence of water, we demonstrate the existence of more deleterious fatigue mechanisms, mechanical rather than chemical in nature. Neglecting to account for mechanical fatigue can lead to gross overestimates in predicted survival rates. Strategies for prolonging the clinical lifetimes of ceramic restorations are proposed based on a crack-containment philosophy. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Ceramic impregnated superabrasives

    Science.gov (United States)

    Radtke, Robert P.; Sherman, Andrew

    2009-02-10

    A superabrasive fracture resistant compact is formed by depositing successive layers of ceramic throughout the network of open pores in a thermally stable self-bonded polycrystalline diamond or cubic boron nitride preform. The void volume in the preform is from approximately 2 to 10 percent of the volume of the preform, and the average pore size is below approximately 3000 nanometers. The preform is evacuated and infiltrated under at least about 1500 pounds per square inch pressure with a liquid pre-ceramic polymerizable precursor. The precursor is infiltrated into the preform at or below the boiling point of the precursor. The precursor is polymerized into a solid phase material. The excess is removed from the outside of the preform, and the polymer is pyrolized to form a ceramic. The process is repeated at least once more so as to achieve upwards of 90 percent filling of the original void volume. When the remaining void volume drops below about 1 percent the physical properties of the compact, such as fracture resistance, improve substantially. Multiple infiltration cycles result in the deposition of sufficient ceramic to reduce the void volume to below 0.5 percent. The fracture resistance of the compacts in which the pores are lined with formed in situ ceramic is generally at least one and one-half times that of the starting preforms.

  7. Diffusion in ceramics

    CERN Document Server

    Pelleg, Joshua

    2016-01-01

    This textbook provides an introduction to changes that occur in solids such as ceramics, mainly at high temperatures, which are diffusion controlled, as well as presenting research data. Such changes are related to the kinetics of various reactions such as precipitation, oxidation and phase transformations, but are also related to some mechanical changes, such as creep. The book is composed of two parts, beginning with a look at the basics of diffusion according to Fick's Laws. Solutions of Fick’s second law for constant D, diffusion in grain boundaries and dislocations are presented along with a look at the atomistic approach for the random motion of atoms. In the second part, the author discusses diffusion in several technologically important ceramics. The ceramics selected are monolithic single phase ones, including: A12O3, SiC, MgO, ZrO2 and Si3N4. Of these, three refer to oxide ceramics (alumina, magnesia and zirconia). Carbide based ceramics are represented by the technologically very important Si-ca...

  8. The potentialities of the complexation ultrafiltration technique for the decontamination of fission product contaminated aqueous effluents; Potentialites de la complexation - ultrafiltration a la decontamination d`effluents radioactifs en produits de fission

    Energy Technology Data Exchange (ETDEWEB)

    Thibert, V

    1995-07-01

    Many nuclear researchers and industrial operators lay emphasis on improving the back end of the fuel cycle. A major problem concerns the liquid wastes generated by the reprocessing plant at La Hague, discharged into the sea after treatment in the Effluent Treatment Station (STE) (3), and which have become crucial matter. The activity of these wastes is well below the current legal limits, and is constantly decreasing these last years. To bring it close to zero, and ambitious goal, entails innovative new reprocessing techniques. We accordingly investigated the possibilities of complexation-ultrafiltration, a technique that uses water-soluble macromolecules to complex the target elements to be separated. We first achieved the strontium (II) separation with poly-acrylic and poly-sulfonic acids. The effects of pH and NaNO{sub 3} concentration influence on Sr (II) complexation were studied. The Sr (II) complexation and concentration phases, followed by cation de-complexation to recover the polymer, were also taken into account. This research, combined with a potentiometric study of the polymers, offered a close understanding of the chemical systems involved, and of the operating conditions and limits of complexation-ultrafiltration. The laboratory results were also validated on a tangential ultrafiltration pilot plant. We then used complexation-ultrafiltration to treat a real effluent generated bu La Hague`s STE 3 plant. This experiment demonstrated minimum 90 % decontamination of Sr (II) (with polyacrylate complexing agent), and also for {sup 134-137}Cs (with simple ultrafiltration). The use of two polyamides allowed partial decontamination of the effluent for {sup 60}Co and {sup 106}Ru. This work therefore offers a global approach to complexation-ultrafiltration, from laboratory to pilot scale, on real and simulated effluents. The future of this technique relies chiefly on the ability to solve the problem of polymer recovery. (Abstract Truncated)

  9. Characterization of a non-fouling ultrafiltration membrane

    DEFF Research Database (Denmark)

    Wei, J.; Helm, G.S.; Corner-Walker, N.

    2006-01-01

    This report describes the properties of surface-modified poly(vinylidene fluoride) (PVDF) membranes. These membranes were created by coating hydrophilic polymers on the support PVDF membrane to reduce the tendency to protein fouling. The modified membranes with different molecular weight cut......-off (MWCO) were characterized by filtration studies using bovine serum albumin (BSA) and an enzyme solution as test media, and the membranes exhibited the non-fouling property. The surface chemistry of the unmodified and modified PVDF membranes was characterized by X-ray photoelectron spectroscopy (XPS......) and time-of-flight secondary ion mass spectroscopy (ToF-SIMS). These surface sensitive techniques were used to confirm the successful surface modification. ToF-SIMS imaging visualizes the distribution of the coating layer on the PVDF membrane. Furthermore, the amount of protein adsorption onto the membrane...

  10. Carprofen pharmacokinetics in plasma and in control and inflamed canine tissue fluid using in vivo ultrafiltration.

    Science.gov (United States)

    Messenger, K M; Wofford, J A; Papich, M G

    2016-02-01

    Measurement of unbound drug concentrations at their sites of action is necessary for accurate PK/PD modeling. The objective of this study was to determine the unbound concentration of carprofen in canine interstitial fluid (ISF) using in vivo ultrafiltration and to compare pharmacokinetic parameters of free carprofen concentrations between inflamed and control tissue sites. We hypothesized that active concentrations of carprofen would exhibit different dispositions in ISF between inflamed vs. normal tissues. Bilateral ultrafiltration probes were placed subcutaneously in six healthy Beagle dogs 12 h prior to induction of inflammation. Two milliliters of either 2% carrageenan or saline control was injected subcutaneously at each probe site, 12 h prior to intravenous carprofen (4 mg/kg) administration. Plasma and ISF samples were collected at regular intervals for 72 h, and carprofen concentrations were determined using HPLC. Prostaglandin E2 (PGE2 ) concentrations were quantified in ISF using ELISA. Unbound carprofen concentrations were higher in ISF compared with predicted unbound plasma drug concentrations. Concentrations were not significantly higher in inflamed ISF compared with control ISF. Compartmental modeling was used to generate pharmacokinetic parameter estimates, which were not significantly different between sites. Terminal half-life (T½) was longer in the ISF compared with plasma. PGE2 in ISF decreased following administration of carprofen. In vivo ultrafiltration is a reliable method to determine unbound carprofen in ISF, and that disposition of unbound drug into tissue is much higher than predicted from unbound drug concentration in plasma. However, concentrations and pharmacokinetic parameter estimates are not significantly different in inflamed vs. un-inflamed tissues. © 2015 John Wiley & Sons Ltd.

  11. Preparation of hydrophilic and antifouling polysulfone ultrafiltration membrane derived from phenolphthalin by copolymerization method

    International Nuclear Information System (INIS)

    Liu, Zhixiao; Mi, Zhiming; Chen, Chunhai; Zhou, Hongwei; Zhao, Xiaogang; Wang, Daming

    2017-01-01

    Graphical abstract: The mechanisms fouling and cleaning process of PSF-COOH membranes (A) the content of carboxyl less than 80%. (B) the content of carboxyl at 80%, 100%. - Highlights: • Phenolphthalin (PPL) containing carboxyl was successfully introduced into the molecule backbone of polysulfone (PSF). • A series of PSF-COOH copolymers with different carboxylation degree was synthesized and prepared as ultrafiltration membranes. • The introduction of PPL significantly improved the hydrophilicity, permeation flux and antifouling property of membranes. • This method is valuable for large-scale industrial production of hydrophilic membrane material. - Abstract: In this task, carboxylated polysulfone (PSF-COOH) was achieved by introducing the monomer of phenolphthalin (PPL) containing carboxyl to the molecule backbone of polysulfone (PSF). And a series of PSF-COOH copolymers with different carboxylation degree was synthesized by adjusting the molar (%) of bisphenol A (BPA) and PPL in direct copolymerization method and was prepared as PSF-COOH ultrafiltration membranes via phase separation method. The effect of PPL molar (%) in copolymers on the morphology, hydrophilicity, permeation flux, antifouling and mechanical properties of membranes was investigated by scanning electron microscope (SEM), atomic force microscope (AFM), water contact angle, ultrafiltration experiments and universal testing machine, respectively. The results showed that with the increased carboxyl content in membranes, the hydrophilicity, permeation fluxes and antifouling properties of membranes gradually increased. When the molar (%) of PPL to BPA was 100:0, the membrane exhibited the highest pure water flux (329.6 L/m"2 h) and the maximum flux recovery rate (92.5%). When the content of carboxyl in the membrane was 80% or more, after three cycles of BSA solution (1 g/L) filtration, the flux recovery rate was basically constant or showed a slightly increase. Thus, it can achieve the goal of

  12. Preparation of hydrophilic and antifouling polysulfone ultrafiltration membrane derived from phenolphthalin by copolymerization method

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zhixiao; Mi, Zhiming; Chen, Chunhai; Zhou, Hongwei; Zhao, Xiaogang; Wang, Daming, E-mail: wangdaming@jlu.edu.cn

    2017-04-15

    Graphical abstract: The mechanisms fouling and cleaning process of PSF-COOH membranes (A) the content of carboxyl less than 80%. (B) the content of carboxyl at 80%, 100%. - Highlights: • Phenolphthalin (PPL) containing carboxyl was successfully introduced into the molecule backbone of polysulfone (PSF). • A series of PSF-COOH copolymers with different carboxylation degree was synthesized and prepared as ultrafiltration membranes. • The introduction of PPL significantly improved the hydrophilicity, permeation flux and antifouling property of membranes. • This method is valuable for large-scale industrial production of hydrophilic membrane material. - Abstract: In this task, carboxylated polysulfone (PSF-COOH) was achieved by introducing the monomer of phenolphthalin (PPL) containing carboxyl to the molecule backbone of polysulfone (PSF). And a series of PSF-COOH copolymers with different carboxylation degree was synthesized by adjusting the molar (%) of bisphenol A (BPA) and PPL in direct copolymerization method and was prepared as PSF-COOH ultrafiltration membranes via phase separation method. The effect of PPL molar (%) in copolymers on the morphology, hydrophilicity, permeation flux, antifouling and mechanical properties of membranes was investigated by scanning electron microscope (SEM), atomic force microscope (AFM), water contact angle, ultrafiltration experiments and universal testing machine, respectively. The results showed that with the increased carboxyl content in membranes, the hydrophilicity, permeation fluxes and antifouling properties of membranes gradually increased. When the molar (%) of PPL to BPA was 100:0, the membrane exhibited the highest pure water flux (329.6 L/m{sup 2} h) and the maximum flux recovery rate (92.5%). When the content of carboxyl in the membrane was 80% or more, after three cycles of BSA solution (1 g/L) filtration, the flux recovery rate was basically constant or showed a slightly increase. Thus, it can achieve the

  13. Analysis of ultrafiltration failure in peritoneal dialysis patients by means of standard peritoneal permeability analysis.

    Science.gov (United States)

    Ho-dac-Pannekeet, M M; Atasever, B; Struijk, D G; Krediet, R T

    1997-01-01

    Ultrafiltration failure (UFF) is a complication of peritoneal dialysis (PD) treatment that occurs especially in long-term patients. Etiological factors include a large effective peritoneal surface area [measured as high mass transfer area coefficient (MTAC) of creatinine], a high effective lymphatic absorption rate (ELAR), a large residual volume, or combinations. The prevalence and etiology of UFF were studied and the contribution of transcellular water transport (TCWT) was analyzed. A new definition of UFF and guidelines for the analysis of its etiology were derived from the results. Peritoneal dialysis unit in the Academic Medical Center in Amsterdam. Cross-sectional study of standard peritoneal permeability analyses (4-hr dwells, dextran 70 as volume marker) with 1.36% glucose in 68 PD patients. Patients with negative net UF (change in intraperitoneal volume, dIPV rate (TCUFR) were lower (p lower residual volume (p = 0.03), and lower TCUFR (p = 0.01). Ultrafiltration failure was associated with a high MTAC creatinine in 3 patients, a high ELAR in 4 patients, and a combination of factors in one. As an additional possible cause, TCWT was studied, using the sodium gradient in the first hour of the dwell, corrected for diffusion (dNA). Five patients had dNA > 5 mmol/L, indicating normal TCWT. The 3 patients with dNA lower TCUFR (p = 0.04). A smaller difference was found between dIPV 3.86% and 1.36% (p = 0.04) compared to the dNA > 5 mmol/L group, but no differences were present for MTAC creatinine, ELAR, residual volume, or glucose absorption. In addition to known factors, impairment of TCWT can be a cause of UFF. A standardized dwell with 1.36% glucose overestimates UFF. Therefore, 3.86% glucose should be used for identification of patients with UFF, especially because it provides additional information on TCWT. Ultrafiltration failure can be defined as net UF exchange.

  14. Concentration of infectious aquatic rhabdoviruses from freshwater and seawater using ultrafiltration.

    Science.gov (United States)

    Grant, Amelia A M; Jakob, Eva; Richard, Jon; Garver, Kyle A

    2011-12-01

    Infectious hematopoietic necrosis virus (IHNV), viral hemorrhagic septicemia virus, and spring viremia of carp virus were concentrated and detected from freshwater and seawater samples by using hollow-fiber ultrafiltration. Within 60 min, virus in a 50-L freshwater or saltwater sample was concentrated more than 70-fold, and virus retention efficiencies were consistently greater than 88%. Retention efficiency was highly dependent upon concentrations of column blocking and sample stabilization solutions. A large column with a surface area of 1.15 m2 and a filtration capacity of 5-200 L exhibited optimal viral retention when blocked with 2% fetal bovine serum (FBS) and when the samples were supplemented with 0.1% FBS. Conversely, a small column with 100-fold less surface area and a filtering capacity of 0.5-2.0 L was optimized when blocked with 1% FBS and when the samples were supplemented with 0.1% FBS. The optimized ultrafiltration procedure was further validated with water from a tank that contained IHNV-exposed juvenile sockeye salmon Oncorhynchus nerka, resulting in an average virus retention efficiency of 91.6 +/- 4.1% (mean +/- SE). Virus quantification of concentrated samples demonstrated that IHNV shedding in sockeye salmon preceded mortality; shedding of the virus was observed to increase significantly as early as 7 d postchallenge and peaked at day 14, when virus levels reached 4.87 x 10(3) plaque-forming units/mL. We conclude that ultrafiltration is a reliable and effective method for concentrating viable aquatic rhabdoviruses from large volumes of water and has application for the analysis of environmental water samples.

  15. High flow ceramic pot filters

    NARCIS (Netherlands)

    van Halem, D.; van der Laan, H.; Soppe, A. I.A.; Heijman, S.G.J.

    2017-01-01

    Ceramic pot filters are considered safe, robust and appropriate technologies, but there is a general consensus that water revenues are limited due to clogging of the ceramic element. The objective of this study was to investigate the potential of high flow ceramic pot filters to produce more

  16. Ceramic composites: Enabling aerospace materials

    Science.gov (United States)

    Levine, S. R.

    1992-01-01

    Ceramics and ceramic matrix composites (CMC) have the potential for significant impact on the performance of aerospace propulsion and power systems. In this paper, the potential benefits are discussed in broad qualitative terms and are illustrated by some specific application case studies. The key issues in need of resolution for the potential of ceramics to be realized are discussed.

  17. Preparation of antifouling ultrafiltration membranes via irradiation induced graft polymerization technique

    International Nuclear Information System (INIS)

    Deng Bo; Liu Zhognying; Lu Xiaofeng; Li Jingye; Yang Xuanxuan; Yu Ming; Zhang Bowu

    2010-01-01

    PVDF powders were irradiated in air at dose of 15 kGy by using gamma-rays. Macromolecular peroxides transformed from free radicals in the irradiated PVDF powders in air can be preserved for long-term at appropriate temperature stably. By mixing acrylic monomers with irradiated PVDF powders then the graft polymerization can be initiated by heating. Then a series of hydrophilic ultrafiltration (UF) membranes were fabricated by dissolving the PVDF-g-PAAc powders in the NMP under phase inversion method. The antifouling performances of UF membranes cast from virgin and grafted PVDF powders were compared. (authors)

  18. Verification of Ceramic Structures

    Science.gov (United States)

    Behar-Lafenetre, Stephanie; Cornillon, Laurence; Rancurel, Michael; De Graaf, Dennis; Hartmann, Peter; Coe, Graham; Laine, Benoit

    2012-07-01

    In the framework of the “Mechanical Design and Verification Methodologies for Ceramic Structures” contract [1] awarded by ESA, Thales Alenia Space has investigated literature and practices in affiliated industries to propose a methodological guideline for verification of ceramic spacecraft and instrument structures. It has been written in order to be applicable to most types of ceramic or glass-ceramic materials - typically Cesic®, HBCesic®, Silicon Nitride, Silicon Carbide and ZERODUR®. The proposed guideline describes the activities to be performed at material level in order to cover all the specific aspects of ceramics (Weibull distribution, brittle behaviour, sub-critical crack growth). Elementary tests and their post-processing methods are described, and recommendations for optimization of the test plan are given in order to have a consistent database. The application of this method is shown on an example in a dedicated article [7]. Then the verification activities to be performed at system level are described. This includes classical verification activities based on relevant standard (ECSS Verification [4]), plus specific analytical, testing and inspection features. The analysis methodology takes into account the specific behaviour of ceramic materials, especially the statistical distribution of failures (Weibull) and the method to transfer it from elementary data to a full-scale structure. The demonstration of the efficiency of this method is described in a dedicated article [8]. The verification is completed by classical full-scale testing activities. Indications about proof testing, case of use and implementation are given and specific inspection and protection measures are described. These additional activities are necessary to ensure the required reliability. The aim of the guideline is to describe how to reach the same reliability level as for structures made of more classical materials (metals, composites).

  19. Ozonation and/or Coagulation - Ceramic Membrane Hybrid for Filtration of Impaired-Quality Source Waters

    KAUST Repository

    Ha, Changwon

    2013-09-01

    When microfiltration (MF) and ultrafiltration (UF) membranes are applied for drinking water treatment/wastewater reuse, membrane fouling is an evitable problem, causing the loss of productivity over time. Polymeric membranes have been often reported to experience rapid and/or problematical fouling, restraining sustainable operation. Ceramic membranes can be effectively employed to treat impaired-quality source waters due to their inherent robustness in terms of physical and chemical stability. This research aimed to identify the effects of coagulation and/or ozonation on ceramic membrane filtration for seawater and wastewater (WW) effluent. Two different types of MF and UF ceramic membranes obtained by sintering (i.e., TAMI made of TiO2+ZrO2) and anodic oxidation process (i.e., AAO made of Al2O3) were employed for bench-scale tests. Precoagulation was shown to play an important role in both enhancing membrane filterability and natural organic matter (NOM) removal efficacy for treating a highorganic surface water. The most critical factors were found to be pH and coagulant dosage with the highest efficiency resulting under low pH and high coagulant dose. Due to the ozone-resistance nature of the ceramic membranes, preozonation allowed the ceramic membranes to be operated at higher flux, especially leading to significant flux improvement when treating seawater in the presence of calcium and magnesium. 4 Dissolved ozone in contact with the TAMI ceramic membrane surface accelerated the formation of hydroxyl (˙OH) radicals in WW effluent treatment. Flux restoration of both ceramic membranes, fouled with seawater and WW effluent, was efficiently achieved by high backwash (BW) pressure and ozone in chemically enhanced backwashing (CEB). Ceramic membranes exhibited a pH-dependent permeate flux while filtering WW effluent, showing reduced fouling with increased pH. On the other hand, for filtering seawater, differences in permeate flux between the two membranes was

  20. Cyclic mechanical fatigue in ceramic-ceramic composites: an update

    International Nuclear Information System (INIS)

    Lewis, D. III

    1983-01-01

    Attention is given to cyclic mechanical fatigue effects in a number of ceramics and ceramic composites, including several monolithic ceramics in which significant residual stresses should be present as a result of thermal expansion mismatches and anisotropy. Fatigue is also noted in several BN-containing ceramic matrix-particulate composites and in SiC fiber-ceramic matrix composites. These results suggest that fatigue testing is imperative for ceramics and ceramic composites that are to be used in applications subject to cyclic loading. Fatigue process models are proposed which provide a rationale for fatigue effect observations, but do not as yet provide quantitative results. Fiber composite fatigue damage models indicate that design stresses in these materials may have to be maintained below the level at which fiber pullout occurs

  1. Porous Alumina and Zirconia Ceramics With Tailored Thermal Conductivity

    Czech Academy of Sciences Publication Activity Database

    Gregorová, E.; Pabst, W.; Sofer, Z.; Jankovský, O.; Matějíček, Jiří

    2012-01-01

    Roč. 395, č. 1 (2012), 012022-012022 ISSN 1742-6588. [European Thermal Sciences Conference (Eurotherm)/6./. Poitiers, 04.09.2012-07.09.2012] Institutional support: RVO:61389021 Keywords : Ceramics * alumina * zirconia * porosity * thermal conductivity * pore-forming agent * oxide ceramics * starch * porosity Subject RIV: JK - Corrosion ; Surface Treatment of Materials http://iopscience.iop.org/1742-6596/395/1/012022/pdf/1742-6596_395_1_012022.pdf

  2. Luminescent Eu3+-doped transparent alumina ceramics with high hardness

    Czech Academy of Sciences Publication Activity Database

    Drdlíková, K.; Klement, R.; Hadraba, Hynek; Drdlík, D.; Galusek, D.; Maca, K.

    2017-01-01

    Roč. 37, č. 14 (2017), s. 4271-4277 ISSN 0955-2219 R&D Projects: GA MŠk(CZ) LQ1601; GA ČR(CZ) GA15-06390S Institutional support: RVO:68081723 Keywords : Aluminia * Europium * Photoluminescence (PL) spectra * Submicrocrystalline powders Subject RIV: JH - Ceramic s, Fire-Resistant Materials and Glass OBOR OECD: Ceramic s Impact factor: 3.411, year: 2016

  3. Distorting the ceramic familiar: materiality and non-ceramic intervention, Conference, Keramik Museum, Germany

    OpenAIRE

    Livingstone, Andrew

    2009-01-01

    Invited conference speaker, Westerwald Keramik Museum, August 2009. Paper title: Distorting the ceramic familiar: materiality and non-ceramic intervention.\\ud \\ud This paper will examine the integration of non-ceramic media into the discourse of ceramics.

  4. Focused ultrasound-modulated glomerular ultrafiltration assessed by functional changes in renal arteries.

    Directory of Open Access Journals (Sweden)

    Feng-Yi Yang

    Full Text Available This study demonstrates the feasibility of using focused ultrasound (FUS to modulate glomerular ultrafiltration by renal artery sonication and determine if protein-creatinine ratios are estimated through vascular parameters. All animal experiments were approved by our Animal Care and Use Committee. The renal arteries of Sprague-Dawley rats were surgically exposed and sonicated at various acoustic power levels using a FUS transducer with a resonant frequency of 1 MHz. The mean peak systolic velocity (PSV of the blood flow was measured by Doppler ultrasound imaging. Urinary protein-creatinine ratios were calculated during the experiments. Histological examination of renal arteries and whole kidneys was performed. The PSV, pulsatility index, and resistance index of blood flow significantly increased in the arteries after FUS sonication without microbubbles (p<0.05. The change in normalized protein-creatinine ratios significantly increased with increasing acoustic power, but such was not observed when microbubbles were administered. Furthermore, no histological changes were observed in the hematoxylin- and eosin-stained sections. Glomerular ultrafiltration is regulated temporarily by renal artery sonication without microbubbles. Monitoring vascular parameters are useful in estimating the normalized change in protein-creatinine ratios.

  5. Pharmacokinetic analysis of flomoxef in children undergoing cardiopulmonary bypass and modified ultrafiltration.

    Science.gov (United States)

    Masuda, Zenichi; Kurosaki, Yuji; Ishino, Kozo; Yamauchi, Keita; Sano, Shunji

    2008-04-01

    Cardiopulmonary bypass (CPB) induces changes in the pharmacokinetics of drugs. The purpose of this study was to model the pharmacokinetics of flomoxef, a cephalosporin antibiotic, in pediatric cardiac surgery. Each patient received a flomoxef dose of 30 mg/kg as a bolus after the induction of anesthesia and an additional dose (1 g for a child weighing or = 10 kg) was injected into the CPB prime. Modified ultrafiltration (MUF) was routinely performed. Blood samples, urine, and ultrafiltrate were collected. In seven patients (group I), serum flomoxef concentration-time courses were analyzed by a modified two-compartment model. Utilizing the estimated parameters, serum concentrations were simulated in another eight patients (group II). The initiation of CPB resulted in an abrupt increase in serum flomoxef concentrations in group I; however, concentrations declined biexponentially. The amount of excreted flomoxef in the urine and by MUF was 47% +/- 8% of the total administered dose. In group II, an excellent fit was found between the values calculated by the program and the observed serum concentrations expressed; most of the performance errors were flomoxef in children undergoing CPB and MUF were well fitted to a modified two-compartment model. Using the kinetic data from this study, the individualization of dosage regimens for prophylactic use of flomoxef might be possible.

  6. Metal removal from aqueous media by polymer-assisted ultrafiltration with chitosan

    Directory of Open Access Journals (Sweden)

    Grégorio Crini

    2017-05-01

    Full Text Available Polymer assisted ultrafiltration (PAUF is a relatively new process in water and wastewater treatment and the subject of an increasing number of papers in the field of membrane science. Among the commercial polymers used, poly(ethyleneimine and poly(acrylic acid are the most popular to complex numerous metal ions. Recently, there is an increasing interest in the use of chitosan, a natural linear polymer, as chelating agent for complexing metals. Chitosan has a high potential in wastewater treatment mainly due to its polyelectrolyte properties at acidic pH. The objectives of this review are to present the PAUF process and to highlight the advantages gained from the use of chitosan in the process of complexation–ultrafiltration. For this, a PAUF-based literature survey has been compiled and is discussed. From these data, chitosan, a biopolymer that is non-toxic to humans and the environment, is found to be effective in removing metal ions and exhibits high selectivity. It might be a promising polyelectrolyte for PAUF purposes.

  7. Crossflow Ultrafiltration for Removing Direct-15 Dye from Wastewater of Textile Industry

    Directory of Open Access Journals (Sweden)

    A.L. Ahmad

    2017-11-01

    Full Text Available Ultrafiltration membrane was used to treat the effluent from textile industries. Crossflow ultrafiltration using GN polymeric membrane was used to remove the dye from textile effluent. A synthetic textile effluent of Direct-15 dye was used. The study focused through the effect of feed concentration, transmembrane pressure and solution’s pH on the permeate flux and percentage of dye removal were investigated. Dye concentration had significant effects on flux values. Under the fixed pressures and pH, the flux decreased while the dye rejection increased with increasing feed concentration. Transmembrane pressure also had significant effect on flux values. Under the fixed feed concentration and pH, the flux increased while dye rejection decreased with increasing pressure. Experiment data showed that the highest flux was observed at pH 4 (acidic condition while the highest dye removal observed at pH 7. Data collection could be used to improve the effectiveness of dye removal from textile industry wastewater using membrane technology.

  8. Novel adsorptive ultrafiltration membranes derived from polyvinyltetrazole-co-polyacrylonitrile for Cu(II) ions removal

    KAUST Repository

    Kumar, Mahendra

    2016-05-04

    Novel adsorptive ultrafiltration membranes were manufactured from synthesized polyvinyltetrazole−co−polyacrylonitrile (PVT−co−PAN) by nonsolvent induced phase separation (NIPS). PVT−co−PAN with various degree of functionalization (DF) was synthesized via a [3+2] cycloaddition reaction at 60°C using a commercial PAN. PVT−co−PAN with varied DF was then explored to prepare adsorptive membranes. The membranes were characterized by surface zeta potential and static water contact angle measurements, scanning electron microscopy as well as atomic force microscopy (AFM) techniques. It was shown that PVT segments contributed to alter the pore size, charge and hydrophilic behavior of the membranes. The membranes became more negatively charged and hydrophilic after addition of PVT segments. The PVT segments in the membranes served as the major binding sites for adsorption of Cu(II) ions from aqueous solution. The maximum adsorption of Cu(II) ions by the membranes in static condition and in a continuous ultrafiltration of 10 ppm solution was attained at pH = 5. The adsorption data suggest that the Freundlich isotherm model describes well Cu(II) ions adsorption on the membranes from aqueous solution. The adsorption capacity obtained from the Freundlich isotherm model was 44.3 mg g−1; this value is higher than other membrane adsorption data reported in the literature. Overall, the membranes fabricated from PVT−co−PAN are attractive for efficient removal of heavy metal ions under the optimized conditions.

  9. Efficient Preparation of Super Antifouling PVDF Ultrafiltration Membrane with One Step Fabricated Zwitterionic Surface.

    Science.gov (United States)

    Zhao, Xinzhen; He, Chunju

    2015-08-19

    On the basis of the excellent fouling resistance of zwitterionic materials, the super antifouling polyvinylidene fluoride (PVDF) membrane was efficiently prepared though one-step sulfonation of PVDF and polyaniline blend membrane in situ. The self-doped sulfonated polyaniline (SPANI) was generated as a novel zwitterionic polymer to improve the antifouling property of PVDF ultrafiltration membrane used in sewage treatment. Surface attenuated total reflection Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, surface zeta potential, and water contact angle demonstrated the successful fabrication of zwitterionic interface by convenient sulfonation modification. The static adsorption fouling test showed the quantified adsorption mass of bovine serum albumin (BSA) pollutant on the PVDF/SPANI membrane surface decreases to 3(±2) μg/cm(2), and the water flux recovery ratio (FRR) values were no less than 95% for the three model pollutants of BSA, sodium alginate (SA), and humic acid (HA), which were corresponding hydrophobic, hydrophilic, and natural pollutants in sewage, respectively. This Research Article demonstrated the antifouling advantages of zwitterionic SPANI and aimed to provide a simple method for the large scale preparation of zwitterionic antifouling ultrafiltration membranes.

  10. A hybrid microbial fuel cell membrane bioreactor with a conductive ultrafiltration membrane biocathode for wastewater treatment

    KAUST Repository

    Malaeb, Lilian; Katuri, Krishna; Logan, Bruce E.; Maab, Husnul; Nunes, Suzana Pereira; Saikaly, Pascal

    2013-01-01

    A new hybrid, air-biocathode microbial fuel cell-membrane bioreactor (MFC-MBR) system was developed to achieve simultaneous wastewater treatment and ultrafiltration to produce water for direct reclamation. The combined advantages of this system were achieved by using an electrically conductive ultrafiltration membrane as both the cathode and the membrane for wastewater filtration. The MFC-MBR used an air-biocathode, and it was shown to have good performance relative to an otherwise identical cathode containing a platinum catalyst. With 0.1 mm prefiltered domestic wastewater as the feed, the maximum power density was 0.38 W/m2 (6.8 W/m3) with the biocathode, compared to 0.82 W/m2 (14.5 W/m3) using the platinum cathode. The permeate quality from the biocathode reactor was comparable to that of a conventional MBR, with removals of 97% of the soluble chemical oxygen demand, 97% NH3-N, and 91% of total bacteria (based on flow cytometry). The permeate turbidity was <0.1 nephelometric turbidity units. These results show that a biocathode MFC-MBR system can achieve high levels of wastewater treatment with a low energy input due to the lack of a need for wastewater aeration. © 2013 American Chemical Society.

  11. Stabilization of flux during dead-end ultra-low pressure ultrafiltration.

    Science.gov (United States)

    Peter-Varbanets, Maryna; Hammes, Frederik; Vital, Marius; Pronk, Wouter

    2010-06-01

    Gravity driven ultrafiltration was operated in dead-end mode without any flushing or cleaning. In contrary to general expectations, the flux value stabilized after about one week of operation and remained constant during an extended period of time (several months). Different surface water types and diluted wastewater were used as feed water and, depending on the feed water composition, stable flux values were in the range of 4-10 L h(-1) m(-2). When sodium azide was added to the feed water to diminish the biological activity, no stabilization of flux occurred, indicating that biological processes play an important role in the flux stabilization process. Confocal laser scanning microscopy revealed the presence of a biofouling layer, of which the structure changed over time, leading to relatively heterogeneous structures. It is assumed that the stabilization of flux is related to the development of heterogeneous structures in the fouling layer, due to biological processes in the layer. The phenomenon of flux stabilization opens interesting possibilities for application, for instance in simple and low-cost ultrafiltration systems for decentralized drinking water treatment in developing and transition countries, independent of energy supply, chemicals, or complex process control. 2010 Elsevier Ltd. All rights reserved.

  12. Application of Combined Cake Filtration-Complete Blocking Model to Ultrafiltration of Skim Milk

    Directory of Open Access Journals (Sweden)

    Mansoor Kazemimoghadam

    2017-10-01

    Full Text Available Membrane ultrafiltration (UF is widely used in dairy industries like milk concentration and dehydration processes. The limiting factor of UF systems is fouling which is defined as the precipitation of solutes in the form of a cake layer on the surface of the membrane. In this study, the combined cake filtration-complete blocking model was compared to cake filtration mechanism for flux data through ultrafiltration of skim milk at constant flow rate. The resistance data also was modeled using cake filtration model and standard blocking model. The effect of different trans-membrane pressures and temperatures on flux decline was then investigated. Based on the results obtained here, the combined complete blocking-cake formation model was in excellent agreement with experimental data. The cake filtration model also provided good data fits and can be applied to solutions whose solutes tend to accumulate on the surface of the membrane in the form of a cake layer. With increasing pressure, the differences between the model and experimental data increased.

  13. Effect of PAC addition on immersed ultrafiltration for the treatment of algal-rich water

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yan, E-mail: zhang.yan113@163.com [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 73 Huanghe Road, Nangang District, Harbin 150090 (China); Tian Jiayu; Nan Jun; Gao Shanshan; Liang Heng; Wang Meilian; Li Guibai [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 73 Huanghe Road, Nangang District, Harbin 150090 (China)

    2011-02-28

    The aim of this study was to evaluate the effect of powdered activated carbon (PAC) addition on the treatment of algal-rich water by immersed ultrafiltration (UF), in terms of permeate quality and membrane fouling. Experiments were performed with a hollow-fiber polyvinyl chloride ultrafiltration membrane at a laboratory scale, 20-25 deg, C and 10 L/(m{sup 2} h) constant permeate flux. UF could achieve an absolute removal of Microcystis aeruginosa cells, but a poor removal of algogenic organic matter (AOM) released into water, contaminants responsible for severe membrane fouling. The addition of 4 g/L PAC to the immersed UF reactor significantly alleviated the development of trans-membrane pressure and enhanced the removal of dissovled organic carbon (by 10.9 {+-} 1.7%), UV{sub 254} (by 27.1 {+-} 1.7%), and microcystins (expressed as MC-LR{sub eq}, by 40.8 {+-} 4.2%). However, PAC had little effect on the rejection of hydrophilic high molecular weight AOM such as carbohydrates and proteins. It was also identified that PAC reduced the concentrations of carbohydrates and proteins in the reactor due to decreased light intensity, as well as the MC-LR{sub eq} concentration by PAC adsorption.

  14. Novel adsorptive ultrafiltration membranes derived from polyvinyltetrazole-co-polyacrylonitrile for Cu(II) ions removal

    KAUST Repository

    Kumar, Mahendra; Shevate, Rahul; Hilke, Roland; Peinemann, Klaus-Viktor

    2016-01-01

    Novel adsorptive ultrafiltration membranes were manufactured from synthesized polyvinyltetrazole−co−polyacrylonitrile (PVT−co−PAN) by nonsolvent induced phase separation (NIPS). PVT−co−PAN with various degree of functionalization (DF) was synthesized via a [3+2] cycloaddition reaction at 60°C using a commercial PAN. PVT−co−PAN with varied DF was then explored to prepare adsorptive membranes. The membranes were characterized by surface zeta potential and static water contact angle measurements, scanning electron microscopy as well as atomic force microscopy (AFM) techniques. It was shown that PVT segments contributed to alter the pore size, charge and hydrophilic behavior of the membranes. The membranes became more negatively charged and hydrophilic after addition of PVT segments. The PVT segments in the membranes served as the major binding sites for adsorption of Cu(II) ions from aqueous solution. The maximum adsorption of Cu(II) ions by the membranes in static condition and in a continuous ultrafiltration of 10 ppm solution was attained at pH = 5. The adsorption data suggest that the Freundlich isotherm model describes well Cu(II) ions adsorption on the membranes from aqueous solution. The adsorption capacity obtained from the Freundlich isotherm model was 44.3 mg g−1; this value is higher than other membrane adsorption data reported in the literature. Overall, the membranes fabricated from PVT−co−PAN are attractive for efficient removal of heavy metal ions under the optimized conditions.

  15. Analysis of alcohol dehydrogenase inhibitors from Desmodium styracifolium using centrifugal ultrafiltration coupled with HPLC-MS

    Directory of Open Access Journals (Sweden)

    Liu Liangliang

    2015-01-01

    Full Text Available Alcohol dehydrogenase (ADH inhibitors play an important role in the treatment of human methanol or ethylene glycol poisoning and the suppression of acetaldehyde accumulation in alcoholics. In this study, centrifugal ultrafiltration coupled with high performance liquid chromatography-mass spectrometry (HPLC-MS was utilized to screen and identify ADH inhibitors from ethyl acetate extract of Desmosium styracifolium (Osb. Merr. The experiment conditions of centrifugal ultrafiltration were optimized. At the optimum conditions (ADH concentration: 37.5 μg mL-1, incubation time: 90 min, pH: 7.0 and temperature: 15°C, formononetin and aromadendrin were successfully screened and identified from ethyl acetate extract of Desmodium styracifolium. The screening result was verified by ADH inhibition assays. The IC50 values of formononetin and aromadendrin were 70.8 and 84.7 μg mL-1, which were accorded with the binding degrees of them. Aromadendrin was first reported to have inhibitory activity on ADH. This method provided an effective way to screen active compounds from natural products.

  16. Dual-Functional Ultrafiltration Membrane for Simultaneous Removal of Multiple Pollutants with High Performance.

    Science.gov (United States)

    Pan, Shunlong; Li, Jiansheng; Noonan, Owen; Fang, Xiaofeng; Wan, Gaojie; Yu, Chengzhong; Wang, Lianjun

    2017-05-02

    Simultaneous removal of multiple pollutants from aqueous solution with less energy consumption is crucial in water purification. Here, a novel concept of dual-functional ultrafiltration (DFUF) membrane is demonstrated by entrapment of nanostructured adsorbents into the finger-like pores of ultrafiltration (UF) membrane rather than in the membrane matrix in previous reports of blend membranes, resulting in an exceptionally high active content and simultaneous removal of multiple pollutants from water due to the dual functions of rejection and adsorption. As a demonstration, hollow porous Zr(OH) x nanospheres (HPZNs) were immobilized in poly(ether sulfone) (PES) UF membranes through polydopamine coating with a high content of 68.9 wt %. The decontamination capacity of DFUF membranes toward multiple model pollutants (colloidal gold, polyethylene glycol (PEG), Pb(II)) was evaluated against a blend membrane. Compared to the blend membrane, the DFUF membranes showed 2.1-fold increase in the effective treatment volume for the treatment of Pb(II) contaminated water from 100 ppb to below 10 ppb (WHO drinking water standard). Simultaneously, the DFUF membranes effectively removed the colloidal gold and PEG below instrument detection limit, however the blend membrane only achieved 97.6% and 96.8% rejection for colloidal gold and PEG, respectively. Moreover, the DFUF membranes showed negligible leakage of nanoadsorbents during testing; and the membrane can be easily regenerated and reused. This study sheds new light on the design of high performance multifunction membranes for drinking water purification.

  17. A hybrid microbial fuel cell membrane bioreactor with a conductive ultrafiltration membrane biocathode for wastewater treatment

    KAUST Repository

    Malaeb, Lilian

    2013-10-15

    A new hybrid, air-biocathode microbial fuel cell-membrane bioreactor (MFC-MBR) system was developed to achieve simultaneous wastewater treatment and ultrafiltration to produce water for direct reclamation. The combined advantages of this system were achieved by using an electrically conductive ultrafiltration membrane as both the cathode and the membrane for wastewater filtration. The MFC-MBR used an air-biocathode, and it was shown to have good performance relative to an otherwise identical cathode containing a platinum catalyst. With 0.1 mm prefiltered domestic wastewater as the feed, the maximum power density was 0.38 W/m2 (6.8 W/m3) with the biocathode, compared to 0.82 W/m2 (14.5 W/m3) using the platinum cathode. The permeate quality from the biocathode reactor was comparable to that of a conventional MBR, with removals of 97% of the soluble chemical oxygen demand, 97% NH3-N, and 91% of total bacteria (based on flow cytometry). The permeate turbidity was <0.1 nephelometric turbidity units. These results show that a biocathode MFC-MBR system can achieve high levels of wastewater treatment with a low energy input due to the lack of a need for wastewater aeration. © 2013 American Chemical Society.

  18. Current advances in screening for bioactive components from medicinal plants by affinity ultrafiltration mass spectrometry.

    Science.gov (United States)

    Chen, Guilin; Huang, Bill X; Guo, Mingquan

    2018-05-21

    Medicinal plants have played an important role in maintaining human health for thousands of years. However, the interactions between the active components in medicinal plants and some certain biological targets during a disease are still unclear in most cases. To conduct the high-throughput screening for small active molecules that can interact with biological targets, which is of great theoretical significance and practical value. The ultrafiltration mass spectrometry (UF-LC/MS) is a powerful bio-analytical method by combining affinity ultrafiltration and liquid chromatography-mass spectrometry (LC/MS), which could rapidly screen and identify small active molecules that bind to biological targets of interest at the same time. Compared with other analytical methods, affinity UF-LC/MS has the characteristics of fast, sensitive and high throughput, and is especially suitable for the complicated extracts of medicinal plants. In this review, the basic principle, characteristics and some most recent challenges in UF-LC/MS have been demonstrated. Meanwhile, the progress and applications of affinity UF-LC/MS in the discovery of the active components from natural medicinal plants and the interactions between small molecules and biological target proteins are also briefly summarised. In addition, the future directions for UF-LC/MS are also prospected. Affinity UF-LC/MS is a powerful tool in studies on the interactions between small active molecules and biological protein targets, especially in the high-throughput screening of active components from the natural medicinal plants. Copyright © 2018 John Wiley & Sons, Ltd.

  19. Piezoelectric displacement in ceramics

    International Nuclear Information System (INIS)

    Stewart, M.; Cain, M.; Gee, M.

    1999-01-01

    This Good Practice Guide is intended to aid a user to perform displacement measurements on piezoelectric ceramic materials such as PZT (lead zirconium titanate) in either monolithic or multilayer form. The various measurement issues that the user must consider are addressed, and good measurement practise is described for the four most suitable methods. (author)

  20. Dense ceramic articles

    International Nuclear Information System (INIS)

    Cockbain, A.G.

    1976-01-01

    A method is described for the manufacture of articles of substantially pure dense ceramic materials, for use in severe environments. Si N is very suitable for use in such environments, but suffers from the disadvantage that it is not amenable to sintering. Some disadvantages of the methods normally used for making articles of Si N are mentioned. The method described comprises mixing a powder of the substantially pure ceramic material with an additive that promotes densification, and which is capable of nuclear transmutation into a gas when exposed to radiation, and hot pressing the mixture to form a billet. The billet is then irradiated to convert the additive into a gas which is held captive in the billet, and it is then subjected to a hot forging operation, during which the captive gas escapes and an article of substantially pure dense ceramic material is forged. The method is intended primarily for use for Si N, but may be applied to other ceramic materials. The additive may be Li or Be or their compounds, to the extent of at least 5 ppm and not more than 5% by weight. Irradiation is effected by proton or neutron bombardment. (UK)

  1. OXYGEN TRANSPORT CERAMIC MEMBRANES

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Sukumar Bandopadhyay; Dr. Nagendfra Nagabhushana

    2001-07-01

    The mechanical properties of model systems were analyzed. A reasonably accurate finite element model was implemented and a rational metric to predict the strength of ceramic/metal concentrical joints was developed. The mode of failure of the ceramic/metal joints was determined and the importance of the mechanical properties of the braze material was assessed. Thermal cycling experiments were performed on the model systems and the results were discussed. Additionally, experiments using the concept of placing diffusion barriers on the ceramic surface to limit the extent of the reaction with the braze were performed. It was also observed that the nature and morphology of the reaction zone depends greatly on the nature of the perovskite structure being used. From the experiments, it is observed that the presence of Cr in the Fe-occupied sites decreases the tendency of Fe to segregate and to precipitate out of the lattice. In these new experiments, Ni was observed to play a major role in the decomposition of the ceramic substrate.

  2. Dissolution of crystalline ceramics

    International Nuclear Information System (INIS)

    White, W.B.

    1982-01-01

    The present program objectives are to lay out the fundamentals of crystalline waste form dissolution. Nuclear waste ceramics are polycrystalline. An assumption of the work is that to the first order, the release rate of a particular radionuclide is the surface-weighted sum of the release rates of the radionuclide from each crystalline form that contains it. In the second order, of course, there will be synergistic effects. There will be also grain boundary and other microstructural influences. As a first approximation, we have selected crystalline phases one at a time. The sequence of investigations and measurements is: (i) Identification of the actual chemical reactions of dissolution including identification of the solid reaction products if such occur. (ii) The rates of these reactions are then determined empirically to give what may be called macroscopic kinetics. (iii) Determination of the rate-controlling mechanisms. (iv) If the rate is controlled by surface reactions, the final step would be to determine the atomic kinetics, that is the specific atomic reactions that occur at the dissolving interface. Our concern with the crystalline forms are in two areas: The crystalline components of the reference ceramic waste form and related ceramics and the alumino-silicate phases that appear in some experimental waste forms and as waste-rock interaction products. Specific compounds are: (1) Reference Ceramic Phases (zirconolite, magnetoplumbite, spinel, Tc-bearing spinel and perovskite); (2) Aluminosilicate phases (nepheline, pollucite, CsAlSi 5 O 12 , Sr-feldspar). 5 figures, 1 table

  3. Ceramic analysis in Greece

    NARCIS (Netherlands)

    Hilditch, J.

    2016-01-01

    Scientific, analytical or ‘archaeometric’ techniques for investigating ceramic material have been used within archaeology for over 50 years and now constitute an indispensable tool for archaeologists in the Aegean world (see Jones 1986 for a detailed summary of early work in Greece and Italy) and

  4. Ceramic solid electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Goodenough, John B. [Center for Materials Science and Engineering, University of Texas at Austin, Austin, TX (United States)

    1997-02-15

    Strategies for the design of ceramic solid electrolytes are reviewed. Problems associated with stoichiometric and doped compounds are compared. In the illustration of design principles, emphasis is given to oxide-ion electrolytes for use in solid-oxide fuel cells, oxygen pumps, and oxygen sensors

  5. Coated ceramic breeder materials

    Science.gov (United States)

    Tam, Shiu-Wing; Johnson, Carl E.

    1987-01-01

    A breeder material for use in a breeder blanket of a nuclear reactor is disclosed. The breeder material comprises a core material of lithium containing ceramic particles which has been coated with a neutron multiplier such as Be or BeO, which coating has a higher thermal conductivity than the core material.

  6. Characterization of natural organic matter treated by iron oxide nanoparticle incorporated ceramic membrane-ozonation process.

    Science.gov (United States)

    Park, Hosik; Kim, Yohan; An, Byungryul; Choi, Heechul

    2012-11-15

    In this study, changes in the physical and structural properties of natural organic matter (NOM) were observed during hybrid ceramic membrane processes that combined ozonation with ultrafiltration ceramic membrane (CM) or with a reactive ceramic membrane (RM), namely, an iron oxide nanoparticles (IONs) incorporated-CM. NOM from feed water and NOM from permeate treated with hybrid ceramic membrane processes were analyzed by employing several NOM characterization techniques. Specific ultraviolet absorbance (SUVA), high-performance size exclusion chromatography (HPSEC) and fractionation analyses showed that the hybrid ceramic membrane process effectively removed and transformed relatively high contents of aromatic, high molecular weight and hydrophobic NOM fractions. Fourier transform infrared spectroscopy (FTIR) and 3-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy revealed that this process caused a significant decrease of the aromaticity of humic-like structures and an increase in electron withdrawing groups. The highest removal efficiency (46%) of hydroxyl radical probe compound (i.e., para-Chlorobenzoic acid (pCBA)) in RM-ozonation process compared with that in CM without ozonation process (8%) revealed the hydroxyl radical formation by the surface-catalyzed reaction between ozone and IONs on the surface of RM. In addition, experimental results on flux decline showed that fouling of RM-ozonation process (15%) was reduced compared with that of CM without ozonation process (30%). These results indicated that the RM-ozonation process enhanced the destruction of NOM and reduced the fouling by generating hydroxyl radicals from the catalytic ozonation in the RM-ozonation process. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Development of ceramic-free antenna feeder

    International Nuclear Information System (INIS)

    Moriyama, S.; Kimura, H.; Fujii, T.; Saigusa, M.; Arai, H.

    1994-01-01

    We have proposed a ceramics-free antenna feeder line employing a ridged waveguide as a local support for IC antenna of next-generation tokamaks. One fourth mock-up model of the all metal waveguide designed for the ITER ICRF system is fabricated and electrical characteristics of the model including the coaxial line - waveguide converter are measured. Power reflection coefficient of the model including the coax-waveguide converter to the input coaxial line is estimated to be less than 15% below the cut-off frequency of 107 MHz and less than 3% above the cut-off frequency. It is found that this ceramics-free antenna support employing a ridged waveguide is quite available for IC antenna of next-generation tokamaks. (author)

  8. Influence of Material Properties on the Ballistic Performance of Ceramics for Personal Body Armour

    OpenAIRE

    Kaufmann, Christian; Cronin, Duane; Worswick, Michael; Pageau, Gilles; Beth, Andre

    2003-01-01

    In support of improved personal armour development, depth of penetration tests have been conducted on four different ceramic materials including alumina, modified alumina, silicon carbide and boron carbide. These experiments consisted of impacting ceramic tiles bonded to aluminum cylinders with 0.50 caliber armour piercing projectiles. The results are presented in terms of ballistic efficiency, and the validity of using ballistic efficiency as a measure of ceramic performance was examined. In...

  9. Composite ceramic blade for a gas turbine

    Energy Technology Data Exchange (ETDEWEB)

    Rossmann, A; Hoffmueller, W; Krueger, W

    1980-06-26

    The gas turbine blade consists of a supporting metal core which has at its lower end a modelled root and a profile blade made of ceramics enclosing it at some distance. The invention deals with a reliable connection between these two parts of the rotor blade: from the top end of the blade core a head protrudes supporting the thin-walled profile blade from below with a projection each pointing into the interior. The design of the projections and supporting surfaces is described and illustrated by drawings.

  10. Planar ceramic membrane assembly and oxidation reactor system

    Science.gov (United States)

    Carolan, Michael Francis; Dyer, legal representative, Kathryn Beverly; Wilson, Merrill Anderson; Ohm, Ted R.; Kneidel, Kurt E.; Peterson, David; Chen, Christopher M.; Rackers, Keith Gerard; Dyer, deceased, Paul Nigel

    2007-10-09

    Planar ceramic membrane assembly comprising a dense layer of mixed-conducting multi-component metal oxide material, wherein the dense layer has a first side and a second side, a porous layer of mixed-conducting multi-component metal oxide material in contact with the first side of the dense layer, and a ceramic channeled support layer in contact with the second side of the dense layer. The planar ceramic membrane assembly can be used in a ceramic wafer assembly comprising a planar ceramic channeled support layer having a first side and a second side; a first dense layer of mixed-conducting multi-component metal oxide material having an inner side and an outer side, wherein the inner side is in contact with the first side of the ceramic channeled support layer; a first outer support layer comprising porous mixed-conducting multi-component metal oxide material and having an inner side and an outer side, wherein the inner side is in contact with the outer side of the first dense layer; a second dense layer of mixed-conducting multi-component metal oxide material having an inner side and an outer side, wherein the inner side is in contact with the second side of the ceramic channeled layer; and a second outer support layer comprising porous mixed-conducting multi-component metal oxide material and having an inner side and an outer side, wherein the inner side is in contact with the outer side of the second dense layer.

  11. Single, composite, and ceramic Nd:YAG 946-nm lasers

    Science.gov (United States)

    Lan, Rui-Jun; Yang, Guang; Zheng-Ping, Wang

    2015-06-01

    Single, composite crystal and ceramic continuous wave (CW) 946-nm Nd:YAG lasers are demonstrated, respectively. The ceramic laser behaves better than the crystal laser. With 5-mm long ceramic, a CW output power of 1.46 W is generated with an optical conversion efficiency of 13.9%, while the slope efficiency is 17.9%. The optimal ceramic length for a 946-nm laser is also calculated. Project supported by the National Natural Science Foundation of China (Grant No. 61405171), the Natural Science Foundation of Shandong Province, China (Grant No. ZR2012FQ014), and the Science and Technology Program of the Shandong Higher Education Institutions of China (Grant No. J13LJ05).

  12. Wonderland of ceramics superplasticity; Ceramics chososei no sekai

    Energy Technology Data Exchange (ETDEWEB)

    Wakai, F. [National Industrial Research Inst. of Nagoya, Nagoya (Japan)

    1995-07-01

    It has been ten years since it was found that ceramics, which is strong and hard at room temperatures and does not deform at all, may exhibit a superplasticity phenomenon at high temperatures that it endlessly elongates when pulled as if it were chewing gum. This phenomenon is one of peculiar behaviours which nano-crystal ceramics, pulverized to an extent that the crystalline particle size is on the order of nanometers, show. The application of superplasticity made the material engineers`s old dream come true that hard ceramics are arbitrarily deformed and machined like metal. Using as models materials such as silicone nitride, alumina and zirconia, this paper describes the history and deformation mechanism of ceramics superplasticity, material design aiming at superplasticization and application of ceramics superplasticity to the machining technology. Furthermore, it describes the trend and future development of international joint researches on the basic surveys on ceramics superplasticity. 25 refs., 11 figs.

  13. Concentration of aqueous extracts of defatted soy flour by ultrafiltration; Effect of suspended particles on the filtration flux

    NARCIS (Netherlands)

    Noordman, T.R.; Kooiker, K.; Bel, W.; Dekker, M.; Wesselingh, J.A.

    2003-01-01

    Suspended particles can have a positive effect on the flux and concentration curve of soy flour extracts during ultrafiltration. This is described by a simple empirical model. The suspended particles in this study were insoluble milled bean material (mean particle size 25 m). It is shown that it is

  14. Analysis of the prevalence and causes of ultrafiltration failure during long-term peritoneal dialysis: a cross-sectional study

    NARCIS (Netherlands)

    Smit, Watske; Schouten, Natalie; van den Berg, Nicole; Langedijk, Monique J.; Struijk, Dirk G.; Krediet, Raymond T.

    2004-01-01

    BACKGROUND: Ultrafiltration failure (UFF) is a major complication of peritoneal dialysis (PD). It can occur at any stage of PD, but develops in time and is, therefore, especially important in long-term treatment. To investigate its prevalence and to identify possible causes, we performed a

  15. Fabrication of TiO_2-modified polytetrafluoroethylene ultrafiltration membranes via plasma-enhanced surface graft pretreatment

    International Nuclear Information System (INIS)

    Qian, Yingjia; Chi, Lina; Zhou, Weili; Yu, Zhenjiang; Zhang, Zhongzhi; Zhang, Zhenjia; Jiang, Zheng

    2016-01-01

    Graphical abstract: - Highlights: • Multifunctional TiO_2/PAA/PTFE ultrafiltration membrane was fabricated via tight coating of TiO_2 functional layer onto the plasma-assisted graft of PAA on PTFE. • The high water flux rate, remarkable enhanced ultrafiltration performance and excellent self-cleaning ability were demonstrated. • The formation of COO−Ti bidentate coordination between TiO_2 and PAA was responsible for the successful coating. - Abstract: Surface hydrophilic modification of polymer ultrafiltration membrane using metal oxide represents an effective yet highly challenging solution to improve water flux and antifouling performance. Via plasma-enhanced graft of poly acryl acid (PAA) prior to coating TiO_2, we successfully fixed TiO_2 functional thin layer on super hydrophobic polytetrafluoroethylene (PTFE) ultrafiltration (UF) membranes. The characterization results evidenced TiO_2 attached on the PTFE-based UF membranes through the chelating bidentate coordination between surface-grafted carboxyl group and Ti"4"+. The TiO_2 surface modification may greatly reduce the water contact angle from 115.8° of the PTFE membrane to 35.0° without degradation in 30-day continuous filtration operations. The novel TiO_2/PAA/PTFE membranes also exhibited excellent antifouling and self-cleaning performance due to the intrinsic hydrophilicity and photocatalysis properties of TiO_2, which was further confirmed by the photo-degradation of MB under Xe lamp irradiation.

  16. Predicting optimal back-shock times in ultrafiltration hollow fiber modules II: Effect of inlet flow and concentration dependent viscosity

    DEFF Research Database (Denmark)

    Vinther, Frank; Pinelo, Manuel; Brøns, Morten

    2015-01-01

    This paper concerns mathematical modeling and computational fluid dynamics of back-shocking during hollow fibre ultrafiltration of dextran T500. In this paper we present a mathematical model based on first Principles, i.e., solving the Navier-Stokes equation along with the continuity equation...

  17. FIBROUS CERAMIC-CERAMIC COMPOSITE MATERIALS PROCESSING AND PROPERTIES

    OpenAIRE

    Naslain , R.

    1986-01-01

    The introduction of continuous fibers in a ceramic matrix can improve its toughness, if the fiber-matrix bonding is weak enough, due to matrix microcracking and fiber pull-out. Ceramic-ceramic composite materials are processed according to liquid or gas phase techniques. The most important are made of glass, carbide, nitride or oxide matrices reinforced with carbon, SiC or Al2O3 fibers.

  18. Novel cellobiose 2-epimerases for the production of epilactose from milk ultrafiltrate containing lactose.

    Science.gov (United States)

    Krewinkel, Manuel; Kaiser, Jana; Merz, Michael; Rentschler, Eva; Kuschel, Beatrice; Hinrichs, Jörg; Fischer, Lutz

    2015-06-01

    A selected number of enzymes have recently been assigned to the emerging class of cellobiose 2-epimerases (CE). All CE convert lactose to the rare sugar epilactose, which is regarded as a new prebiotic. Within this study, the gene products of 2 potential CE genes originating from the mesophilic bacteria Cellulosilyticum lentocellum and Dysgonomonas gadei were recombinantly produced in Escherichia coli and purified by chromatography. The enzymes have been identified as novel CE by sequence analysis and biochemical characterizations. The biochemical characterizations included the determination of the molecular weight, the substrate spectrum, and the kinetic parameters, as well as the pH and temperature profiles in buffer and food matrices. Both identified CE epimerize cellobiose and lactose into the C2 epimerization products glucosylmannose and epilactose, respectively. The epimerization activity for lactose was maximal at pH 8.0 or 7.5 and 40°C in defined buffer systems for the CE from C. lentocellum and the CE from D. gadei, respectively. In addition, biotransformations of the foodstuff milk ultrafiltrate containing lactose were demonstrated. The CE from D. gadei was produced in a stirred-tank reactor (12 L) and purified using an automatic system. Enzyme production and purification in this scale indicates that a future upscaling of CE production is possible. The bioconversions of lactose in milk ultrafiltrate were carried out either in a batch process or in a continuously operated enzyme membrane reactor (EMR) process. Both processes ran at an industrially relevant low temperature of 8°C to reduce undesirable microbial growth. The enzyme was reasonably active at the low process temperature because the CE originated from a mesophilic organism. An epilactose yield of 29.9% was achieved in the batch process within 28 h of operation time. In the continuous EMR process, the epilactose yield in the product stream was lower, at 18.5%. However, the enzyme productivity

  19. Physicochemical and Microbiological Properties of Yogurt-cheese Manufactured with Ultrafiltrated Cow's Milk and Soy Milk Blends

    Science.gov (United States)

    Lee, Na-Kyoung; Mok, Bo Ram; Jeewanthi, Renda Kankanamge Chaturika; Yoon, Yoh Chang; Paik, Hyun-Dong

    2015-01-01

    The objective of this study was to develop yogurt-cheese using cow’s milk, ultrafiltrated cow’s milk, and soy milk. The addition of soy milk and ultrafiltrated milk increased the amount of protein in the yogurt-cheese. Yogurt-cheeses were made using cheese base using 10% and 20% soy milk with raw and ultrafiltrated cow’s milk, and stored at 4℃ during 2 wk. The yield of yogurt-cheeses made with added soy milk was decreased and the cutting point was delayed compared to yogurt-cheese made without soy milk. Yogurt-cheese made using ultrafiltrated cow’s milk showed the highest yield. However, yogurt-cheese made with added soy milk had higher protein content and titratable acidity than yogurt-cheese made using raw and ultrafiltrated cow’s milk. Fat and lactose contents in the yogurt-cheese made with added soy milk were lower. Yogurt-cheeses made with added soy milk contained several soy protein bands corresponding to the sizes of α2-, β-, and κ-casein band. Yogurt-cheese made with added soy milk had similar elasticity to yogurt-cheese made without soy milk but had lower cohesiveness. There was no significant difference in the number of lactic acid bacteria in the different cheeses, as all had over 8.0 Log CFU/g. Considering these data and the fact that proteins and fats of vegetable origin with high biological value were observed as well as unsaturated fats, yogurt-cheese made with added soy milk can be considered to be a functional food. PMID:26761829

  20. Positron annihilation in transparent ceramics

    Science.gov (United States)

    Husband, P.; Bartošová, I.; Slugeň, V.; Selim, F. A.

    2016-01-01

    Transparent ceramics are emerging as excellent candidates for many photonic applications including laser, scintillation and illumination. However achieving perfect transparency is essential in these applications and requires high technology processing and complete understanding for the ceramic microstructure and its effect on the optical properties. Positron annihilation spectroscopy (PAS) is the perfect tool to study porosity and defects. It has been applied to investigate many ceramic structures; and transparent ceramics field may be greatly advanced by applying PAS. In this work positron lifetime (PLT) measurements were carried out in parallel with optical studies on yttrium aluminum garnet transparent ceramics in order to gain an understanding for their structure at the atomic level and its effect on the transparency and light scattering. The study confirmed that PAS can provide useful information on their microstructure and guide the technology of manufacturing and advancing transparent ceramics.

  1. Positron annihilation in transparent ceramics

    International Nuclear Information System (INIS)

    Husband, P; Selim, F A; Bartošová, I; Slugeň, V

    2016-01-01

    Transparent ceramics are emerging as excellent candidates for many photonic applications including laser, scintillation and illumination. However achieving perfect transparency is essential in these applications and requires high technology processing and complete understanding for the ceramic microstructure and its effect on the optical properties. Positron annihilation spectroscopy (PAS) is the perfect tool to study porosity and defects. It has been applied to investigate many ceramic structures; and transparent ceramics field may be greatly advanced by applying PAS. In this work positron lifetime (PLT) measurements were carried out in parallel with optical studies on yttrium aluminum garnet transparent ceramics in order to gain an understanding for their structure at the atomic level and its effect on the transparency and light scattering. The study confirmed that PAS can provide useful information on their microstructure and guide the technology of manufacturing and advancing transparent ceramics. (paper)

  2. Ceramics for fusion applications

    International Nuclear Information System (INIS)

    Clinard, F.W. Jr.

    1987-01-01

    Ceramics are required for a variety of uses in both near-term fusion devices and in commercial powerplants. These materials must retain adequate structural and electrical properties under conditions of neutron, particle and ionizing irradiation; thermal and applied stresses; and physical and chemical sputtering. Ceramics such as Al 2 O 3 , MgAl 2 O 4 , BeO, Si 3 N 4 and SiC are currently under study for fusion applications, and results to date show widely-varying responses to the fusion environment. Materials can be identified today that will meet initial operating requirements, but improvements in physical properties are needed to achieve satisfactory lifetimes for critical applications. (author)

  3. Ceramics for fusion applications

    International Nuclear Information System (INIS)

    Clinard, F.W. Jr.

    1986-01-01

    Ceramics are required for a variety of uses in both near-term fusion devices and in commercial powerplants. These materials must retain adequate structural and electrical properties under conditions of neutron, particle, and ionizing irradiation; thermal and applied stresses; and physical and chemical sputtering. Ceramics such as Al 2 O 3 , MgAl 2 O 4 , BeO, Si 3 N 4 and SiC are currently under study for fusion applications, and results to date show widely-varying response to the fusion environment. Materials can be identified today which will meet initial operating requirements, but improvements in physical properties are needed to achieve satisfactory lifetimes for critical applications

  4. Ceramic Composite Thin Films

    Science.gov (United States)

    Ruoff, Rodney S. (Inventor); Stankovich, Sasha (Inventor); Dikin, Dmitriy A. (Inventor); Nguyen, SonBinh T. (Inventor)

    2013-01-01

    A ceramic composite thin film or layer includes individual graphene oxide and/or electrically conductive graphene sheets dispersed in a ceramic (e.g. silica) matrix. The thin film or layer can be electrically conductive film or layer depending the amount of graphene sheets present. The composite films or layers are transparent, chemically inert and compatible with both glass and hydrophilic SiOx/silicon substrates. The composite film or layer can be produced by making a suspension of graphene oxide sheet fragments, introducing a silica-precursor or silica to the suspension to form a sol, depositing the sol on a substrate as thin film or layer, at least partially reducing the graphene oxide sheets to conductive graphene sheets, and thermally consolidating the thin film or layer to form a silica matrix in which the graphene oxide and/or graphene sheets are dispersed.

  5. Advanced ceramic in structural engineering

    OpenAIRE

    Alonso Rodea, Jorge

    2012-01-01

    The work deals with "Advanced Ceramics in Structural Engineering”. Throughout this work we present the different types of ceramic that are currently in wider use, and the main research lines that are being followed. Ceramics have very interesting properties, both mechanical and electrical and refractory where we can find some of the most interesting points of inquiry. Through this work we try tounderstand this complex world, analyzing both general and specific properties of ...

  6. Influence of Material Properties on the Ballistic Performance of Ceramics for Personal Body Armour

    Directory of Open Access Journals (Sweden)

    Christian Kaufmann

    2003-01-01

    Full Text Available In support of improved personal armour development, depth of penetration tests have been conducted on four different ceramic materials including alumina, modified alumina, silicon carbide and boron carbide. These experiments consisted of impacting ceramic tiles bonded to aluminum cylinders with 0.50 caliber armour piercing projectiles. The results are presented in terms of ballistic efficiency, and the validity of using ballistic efficiency as a measure of ceramic performance was examined. In addition, the correlation between ballistic performance and ceramic material properties, such as elastic modulus, hardness, spall strength and Hugoniot Elastic Limit, has been considered.

  7. Ceramic superconductors II

    International Nuclear Information System (INIS)

    Yan, M.F.

    1988-01-01

    This volume compiles papers on ceramic superconductors. Topics include: structural patterns in High-Tc superconductors, phase equilibria of barium oxide superconductors, localized electrons in tetragonal YBa/sub 2/Cu/sub 3/O/sub 7-δ/, lattice and defect structure and properties of rare earth/alkaline earth-copper-oxide superconductors, alternate candidates for High-Tc superconductors, perovskite-structure superconductors; superconductive thin film fabrication, and superconductor/polymer composites

  8. Piezoelectric Ceramics Characterization

    National Research Council Canada - National Science Library

    Jordan, T

    2001-01-01

    ... the behavior of a piezoelectric material. We have attempted to cover the most common measurement methods as well as introduce parameters of interest. Excellent sources for more in-depth coverage of specific topics can be found in the bibliography. In most cases, we refer to lead zirconate titanate (PZT) to illustrate some of the concepts since it is the most widely used and studied piezoelectric ceramic to date.

  9. Property-porosity relationships for polymer-impregnated superconducting ceramic composite

    International Nuclear Information System (INIS)

    Salib, S.; Vipulanandan, C.

    1990-01-01

    A thermoplastic polymer, poly(methyl methacrylate) (PMMA), was used to improve the flexural properties of the high-temperature superconducting ceramic (YBa 2 Cu 3 O 7-δ ). Ceramic specimens with different porosities were prepared by dry compacting 12.5-mm-diameter disk specimens at various uniaxial pressures. Density-pressure relationships have been developed for before- and after-sintering conditions. The PMMA polymer was impregnated into the porous ceramic at room temperature. The mechanical properties were evaluated by concentrically loading simply supported disk specimens. The load-displacement responses were analyzed using the finite-element method. Impregnation of PMMA polymer at room temperature increased the flexural strength and modulus of the superconducting ceramic without affecting its electrical properties. The flexural properties depended on the porosity of the ceramics, and, hence, linear and nonlinear property-porosity relationships have been used to characterize the behavior of superconducting ceramic with an without the polymer

  10. Synthesis of carbon nanotubes by CVD method using iron and molybdenum-based catalysts supported on ceramic matrices;Sintese de nanotubos de carbono por CVD utilizando catalisadores a base de ferro e molibdenio suportados em matrizes ceramicas

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Ana Paula de Carvalho

    2010-07-01

    Molybdenum is known for its synergistic effect in the synthesis of carbon nanotubes (CNs) by chemical vapor deposition (CVD method). When added to typical catalysts like iron, nickel, and cobalt, even in small quantities, it is increases the yield of these nanostructures. The presence of Mo also has an influence on the type and number of CN walls formed. Although this effect is widely documented in the literature, there is not yet a consensus about the mechanism of action of molybdenum in catalytic systems. The objective of the present work is to study the influence of molybdenum on the catalytic activity of iron nanoparticle-based catalysts supported on magnesium oxide (Fe/MgO system) in the synthesis of carbon nanotubes by the CVD method. The Mo concentration was systematically varied from null to molar ratio values four times greater than the quantity of Fe, and the obtained material (catalysts and carbon nanotubes) were broadly characterized by different techniques. In order to also study the influence of the preparation method on the final composition of the catalytic system phases, the catalytic systems (Fe/MgO e FeMo{sub x}/MgO) were synthesized by two different methods: co-precipitation and impregnation. The greatest CN yields were observed for the catalysts prepared by coprecipitation. The difference was attributed to better dispersion of the Fe and Mo phases in the catalyst ceramic matrix. In the precipitation stage, it was observed the formation of layered double hydroxides whose concentration increased with the Mo content up to the ratio of Mo/Fe equal to 0.2. This phase is related to a better distribution of Fe and Mo in this concentration range. Another important characteristic observed is that the ceramic matrix is not inert. It can react both with Fe and Mo and form the iron solid solution in the magnesium oxide and the phases magnesium-ferrite (MgFe{sub 2}0{sub 4}) and magnesium molybdate (MgMo0{sub 4}). The MgFe{sub 2}0{sub 4} phase is observed in

  11. Ion conductivity of nasicon ceramics

    International Nuclear Information System (INIS)

    Hoj, J.W.; Engell, J.

    1989-01-01

    The Nasicon ss ,Na 1 + X Zr 2 Si X P 3 - X O 12 o , X , 3, includes some of the best solid state sodium conductors known today. Compositions in the interval 1.6 , X , 2.6 show conductivities comparable to the best β double-prime-alumina ceramics. It is well known that the ion conductivity of β-alumina is strongly dependent on the texture of the ceramic. Here a similar behavior is reported for Nasicon ceramics. Ceramics of the bulk composition Na 2.94 Zr 1.49 Si 2.20 P 0.80 O 10.85 were prepared by a gel method. The final ceramics consist of Nasicon crystals with x = 2.14 and a glass phase. The grain size and texture of the ceramics were controlled by varying the thermal history of the gel based raw materials and the sintering conditions. The room temperature resistivity of the resulting ceramics varies from 3.65*10 3 ohm cm to 1.23*10 3 ohm cm. Using the temperature comparison method and estimates of the area of grain boundaries in the ceramics, the resistivity of the Nasicon phase is estimated to be 225 ohm cm at 25 degrees C. B 2 O 3 - or Al 2 O 3 -doping of the glass bearing Nasicon ceramic lower the room temperature resistivity by a factor 2 to 5. The dopants do not substitute into the Nasicon phase in substantial amounts

  12. A Review of Ultrafiltration and Forward Osmosis:application and modification

    Science.gov (United States)

    Chao, Gong; Shuili, Yu; Yufei, Shangguan; Zhengyang, Gu; Wangzhen, Yang; Liumo, Ren

    2018-03-01

    As a new treatment, membrane filtration is playing a more prominent role in treating many kinds of wastewater. Among all the membrane technologies, ultrafiltration(UF) and forward osmosis(FO) technology has been widely utilized and developed in oil field and refinery produced water. However, the reports about the differences between the two kinds of membrane technology used in oily wastewater are not yet available. In this review, at first we introduce the advantages, shortcomings and applications of UF and FO membranes. Among these, we mainly illustrate the membrane fouling, which now is a big problem because it increases costs and decreases membrane life to limit the industrialization of the membrane, and the different modification methods of membranes are discussed to figure out how these ways can ease the membrane fouling. Next we make a comparison of the two membranes. Finally we illustrate the future research topics.

  13. Performance study of ultrafiltration membrane with bovine serum albumin as feed solution

    International Nuclear Information System (INIS)

    Syahril Ahmad

    2009-01-01

    Bovine serum albumin solutions at different temperature, pH, flow rate and operation pressure have been used as feed solution for studying performance of ultrafiltration membrane. Polysulfone membranes used for this experiment were in form of hollow fibers that have Molecular Weight Cut Off (MWCO) 60 kDa. Observation was focused on flux parameter and rejection coefficient towards protein during the process. Result shows that temperature, pH of BSA feed solution, flow rate and operation pressure can affect the flux and rejection coefficient of membrane. High temperature feed solution tend to decrease the flux but increase rejection coefficient. Rejection coefficient of membrane will increase while flux decreasing at pH of feed solution near to protein isoelectric point. High pressure of feed solution will increase flux but decrease rejection of membrane. Rejection of membrane will decrease and flux will increase when the process operated in slow flow rate. (author)

  14. Preparation, Characterization and Performance Studies of Active PVDF Ultrafiltration-Surfactants Membranes Containing PVP as Additive

    International Nuclear Information System (INIS)

    Nur Izzah Md Fadilah; Abdul Rahman Hassan

    2016-01-01

    The role of surfactants in the formation of active Poly(vinylidene fluoride) (PVDF) ultrafiltration (AUF) membranes was studied. The effect combination of surfactants that are Sodium dodecyl sulfate (SDS)/ Tween 80 and Tween 80/ Triton X-100 formulations on performance and morphological structures were investigated for the first time. The influence of surfactants blends on the membrane pores was also examined. Experimental data showed that combination of Tween 80/ Triton X-100 give the highest BSA permeation flux with a value of 285.51 Lm -2 h -1 . With combination of SDS/ Tween 80, the AUF membrane showed the highest protein rejection up to 93 % and 79 % for Bovine Serum Albumin (BSA) and Egg Albumin (EA), respectively. Moreover, membranes characterization demonstrated that the addition of SDS/ Tween 80 and Tween 80/ Triton X-100 were found to affect the performance, surface morphologies and membrane pores of AUF PVDF membranes. (author)

  15. Safety of a new, ultrafiltrated whey hydrolysate formula in children with cow milk allergy

    DEFF Research Database (Denmark)

    Halken, S; Høst, A; Hansen, L G

    1993-01-01

    The purpose of this study was to determine whether a new ultrafiltrated whey hydrolysate infant formula, Profylac, could be administered safely to children with cow milk protein allergy/intolerance. Profylac has a stated molecular weight of ... which is controlled by a combination of ELISA-techniques and immunochemical methods. The study comprised 66 children with cow milk protein allergy/intolerance diagnosed by controlled elimination/challenge procedures. The children were aged 1 month-14.5 years, median 1 11/12 years and 15 were below 1...... year. Thirty-five of these children had proven IgE-mediated reactions (cow milk protein allergy). Sixty-one of the children had at least two different symptoms and 31 had concomitant allergies to other foods and/or inhalants. All 66 children underwent and tolerated open, controlled challenges...

  16. Liquid Whey Protein Concentrates Produced by Ultrafiltration as Primary Raw Materials for Thermal Dairy Gels

    Directory of Open Access Journals (Sweden)

    Marta Henriques

    2017-01-01

    Full Text Available The aim of this work is to study the gelation properties of liquid whey protein concentrates (LWPC produced by ultrafiltration (UF as raw material for thermally induced gels intended for food applications. LWPC thermal gelation was performed using different types of LWPC (non-defatted, defatted and diafiltered of different protein mass fractions and pH. Most of the produced gels showed viscoelastic behaviour. Non-defatted LWPC gave stronger heat-induced gels with a more cohesive microstructure, a higher water holding capacity and also higher elastic modulus (G’ and viscous modulus (G’’. Gel properties were not improved in products with lower content of non-protein compounds. As expected, the increase in protein mass fraction positively influences protein interactions. However, the pH is responsible for the equilibrium between attraction and repulsion forces in the gel components that influence gel hardness and water holding capacity.

  17. Study on cross-flow ultrafiltration for the radioactive liquid waste treatment

    International Nuclear Information System (INIS)

    Jung, K. H.; Jo, E. S.; Lee, D. G.; Lee, G. W.; Jung, K. J.

    2000-01-01

    The effect of the UF membranes on permeate flux was investigated in the ultrafiltration of dodecane (0.1v%) / water emulsion and dodecane-SDS-water emulsion in view of the treatment of radioactive oily emulsion liquid waste in the future. For variety of membranes, experiments in cross-flow modes have been performed at various pressure and different cross-flow velocities. Permeate flux decreased with the time and reached a constant steady-state value. Steady-state flux was found to be dependent by the hydrodynamic conditions but independent by the pressure. Flux decrease and rates of permeate flow resistance change have been analysed using a formulation of the equations illustrating the method of resistance mechanism recognition

  18. Polyethersulfone/Graphene Oxide Ultrafiltration Membranes from Solutions in Ionic Liquid

    KAUST Repository

    Mahalingam, Dinesh. K.; Kim, DooLi.; Nunes, Suzana. P.

    2017-01-01

    Novel high flux polyethersulfone (PES) ultrafiltration membranes were fabricated by incorporating different amounts of graphene oxide (GO) sheets to PES as nanofillers. The membranes were prepared from solutions in 50/50 1-ethyl-3-methylimidazolium-diethylphosphate/N,N-dimethyl formamide. It was observed that the water permeance increased from 550 to 800 L m-2h-1bar-1, with incorporation of 1 wt% GO, keeping a molecular weight cut-off (MWCO) of approximately 32-34 kg mol-1. Cross-sectional scanning electron microscopy images of GO/PES membranes showed the formation of ultrathin selective layer unlike pristine membranes. Contact angle measurements confirmed the increase of hydrophilicity, by increasing the GO concentration. The rejection of humic acid and bovine serum albumin was demonstrated. The mechanical properties were improved, compared with the pristine membranes. The performance was just above the trade-off relationship between permeance and separation factor for PES membranes reported in the literature.

  19. Development of a Model for a Continuous Ultra-Filtration System

    DEFF Research Database (Denmark)

    Jhamb, Spardha Virendra; Gani, Rafiqul; Rype, Jens-Ulrik

    Due to the wide applicability and simplicity of the ultra-filtration process, it is currently being used in a variety of commercial processes for the purpose of separation and concentration of valuable products and/or recovery of raw materials from dilute systems [1]. A predictive model......) system consisting of different geometry (and ‘N’ membrane stacks) used for the concentration of enzyme solutions from a known inlet concentration to a desired (target) outlet concentration during the recovery and/or downstream processing of enzymes. The envisaged purpose of this model is to improve...... for a system derived from first principles, is instrumental in evading the costs of conducting time-consuming experiments while also allowing one to not be dependent on a trial and error analysis approach. The validated final model can serve to understand the operational issues of the process and from...

  20. Characterization of Irreversible Fouling after Ultrafiltration of Thermomechanical Pulp Mill Process Water

    DEFF Research Database (Denmark)

    Thuvander, Johan; Zarebska, Agata; Hélix-Nielsen, Claus

    2018-01-01

    process streams is fouling of the membranes. Fouling not only increases operating costs but also reduces the operating time of the membrane plant. When optimizing the membrane cleaning method, it is important to know which compounds cause the fouling. In this work fouling of an ultrafiltration membrane...... was studied. The fouling propensity of untreated process water and microfiltrated process water was compared. Fouled membranes were analyzed using scanning electron microscopy and attenuated total reflection Fourier transform infrared spectrometry. Acid hydrolysis of membranes exposed to untreated process......Large volumes of wastewater with dissolved wood components are treated in wastewater treatment plants at thermomechanical pulp mills. It has been shown previously that hemicelluloses in these wastewater streams can be recovered by membrane filtration. A serious obstacle when treating lignocellulose...

  1. Polyethersulfone/Graphene Oxide Ultrafiltration Membranes from Solutions in Ionic Liquid

    KAUST Repository

    Mahalingam, Dinesh. K.

    2017-07-18

    Novel high flux polyethersulfone (PES) ultrafiltration membranes were fabricated by incorporating different amounts of graphene oxide (GO) sheets to PES as nanofillers. The membranes were prepared from solutions in 50/50 1-ethyl-3-methylimidazolium-diethylphosphate/N,N-dimethyl formamide. It was observed that the water permeance increased from 550 to 800 L m-2h-1bar-1, with incorporation of 1 wt% GO, keeping a molecular weight cut-off (MWCO) of approximately 32-34 kg mol-1. Cross-sectional scanning electron microscopy images of GO/PES membranes showed the formation of ultrathin selective layer unlike pristine membranes. Contact angle measurements confirmed the increase of hydrophilicity, by increasing the GO concentration. The rejection of humic acid and bovine serum albumin was demonstrated. The mechanical properties were improved, compared with the pristine membranes. The performance was just above the trade-off relationship between permeance and separation factor for PES membranes reported in the literature.

  2. Modeling the improvement of ultrafiltration membrane mass transfer when using biofiltration pretreatment in surface water applications.

    Science.gov (United States)

    Netcher, Andrea C; Duranceau, Steven J

    2016-03-01

    In surface water treatment, ultrafiltration (UF) membranes are widely used because of their ability to supply safe drinking water. Although UF membranes produce high-quality water, their efficiency is limited by fouling. Improving UF filtrate productivity is economically desirable and has been attempted by incorporating sustainable biofiltration processes as pretreatment to UF with varying success. The availability of models that can be applied to describe the effectiveness of biofiltration on membrane mass transfer are lacking. In this work, UF water productivity was empirically modeled as a function of biofilter feed water quality using either a quadratic or Gaussian relationship. UF membrane mass transfer variability was found to be governed by the dimensionless mass ratio between the alkalinity (ALK) and dissolved organic carbon (DOC). UF membrane productivity was optimized when the biofilter feed water ALK to DOC ratio fell between 10 and 14. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Removal of paraquat and linuron from water by continuous flow adsorption/ ultrafiltration membrane processes

    International Nuclear Information System (INIS)

    Zahoor, M.

    2013-01-01

    The magnetic activated carbon (MAC) was prepared, characterized and compared with powdered activated carbon (PAC) for its adsorptive parameters. Both adsorbents were then used in combination ultrafiltration (UF) membrane as pretreatment for the removal of paraquat and linuron from water. The comparison of membrane parameters like percent retention, permeate flux and backwash times for PAC/UF and MAC/UF hybrid processes showed that percent retention of paraquat and linuron was high for PAC due to its high surface area. However due to cake formation over membrane surface the decline permeate fluxes and long backwash times for PAC were observed. PAC also caused blackening of pipes and flow meter. MAC (an iron oxide and PAC composite) was removed from slurry through magnet thus no cake formation and secondary problems observed for PAC was not encountered. Also the backwash times were minimum for MAC/UF process. (author)

  4. Polypropylene Track Membranes for Mikro and Ultrafiltration of Chemically Aggressive Agents

    CERN Document Server

    Kravets, L I; Apel, P Yu

    2000-01-01

    A production process for track membranes on the basis of chemically resistant polymer polypropylene has been developed. Research in all stages of the formation of the polypropylene track membranes has been conducted: the main principles of the process of chemical etching of polypropylene irradiated with accelerated ions have been investigated, the most effective structure of the etchant for a selective etching of the heavy ion tracks has been selected, the parameters of etching have been optimized. A method for sensibilization of latent tracks in polypropylene by effect of solvents has been developed. It helps to reach a significant increase in etching selectivity. A method for destruction of an absorbed chromocontaining layer on the surface of polypropylene track membranes formed during etching has been elaborated. Experimental samples of the membranes for micro and ultrafiltration have been obtained and their properties have been studied in course of their exploitation in chemically aggressive agents. For t...

  5. Antifouling Ultrafiltration Membranes via Post-Fabrication Grafting of Biocidal Nanomaterials

    KAUST Repository

    Mauter, Meagan S.; Wang, Yue; Okemgbo, Kaetochi C.; Osuji, Chinedum O.; Giannelis, Emmanuel P.; Elimelech, Menachem

    2011-01-01

    Figure Presented: Ultrafiltration (UF) membranes perform critical pre-treatment functions in advanced water treatment processes. In operational systems, however, biofouling decreases membrane performance and increases the frequency and cost of chemical cleaning. The present work demonstrates a novel technique for covalently or ionically tethering antimicrobial nanoparticles to the surface of UF membranes. Silver nanoparticles (AgNPs) encapsulated in positively charged polyethyleneimine (PEI) were reacted with an oxygen plasma modified polysulfone UF membrane with and without 1-ethyl-3-(3- dimethylaminopropyl) carbodiimide hydrochloride (EDC) present. The nucleophilic primary amines of the PEI react with the electrophilic carboxyl groups on the UF membrane surface to form electrostatic and covalent bonds. The irreversible modification process imparts significant antimicrobial activity to the membrane surface. Post-synthesis functionalization methods, such as the one presented here, maximize the density of nanomaterials at the membrane surface and may provide a more efficient route for fabricating diverse array of reactive nanocomposite membranes. © 2011 American Chemical Society.

  6. Antifouling Ultrafiltration Membranes via Post-Fabrication Grafting of Biocidal Nanomaterials

    KAUST Repository

    Mauter, Meagan S.

    2011-08-24

    Figure Presented: Ultrafiltration (UF) membranes perform critical pre-treatment functions in advanced water treatment processes. In operational systems, however, biofouling decreases membrane performance and increases the frequency and cost of chemical cleaning. The present work demonstrates a novel technique for covalently or ionically tethering antimicrobial nanoparticles to the surface of UF membranes. Silver nanoparticles (AgNPs) encapsulated in positively charged polyethyleneimine (PEI) were reacted with an oxygen plasma modified polysulfone UF membrane with and without 1-ethyl-3-(3- dimethylaminopropyl) carbodiimide hydrochloride (EDC) present. The nucleophilic primary amines of the PEI react with the electrophilic carboxyl groups on the UF membrane surface to form electrostatic and covalent bonds. The irreversible modification process imparts significant antimicrobial activity to the membrane surface. Post-synthesis functionalization methods, such as the one presented here, maximize the density of nanomaterials at the membrane surface and may provide a more efficient route for fabricating diverse array of reactive nanocomposite membranes. © 2011 American Chemical Society.

  7. Post-treatment of Plasma-Sprayed Amorphous Ceramic Coatings by Spark Plasma Sintering

    Czech Academy of Sciences Publication Activity Database

    Chráska, Tomáš; Pala, Zdeněk; Mušálek, Radek; Medřický, Jan; Vilémová, Monika

    2015-01-01

    Roč. 24, č. 4 (2015), s. 637-643 ISSN 1059-9630 R&D Projects: GA ČR GAP107/12/1922 Institutional support: RVO:61389021 Keywords : ceramic s * heat treatment * nanostructured materials Subject RIV: JH - Ceramic s, Fire-Resistant Materials and Glass Impact factor: 1.568, year: 2015

  8. Biomimetic synthesis of cellular SiC based ceramics from plant ...

    Indian Academy of Sciences (India)

    Unknown

    SiC based materials so derived can be used in structural applications and in designing high temperature filters and catalyst supports. Keywords. Biomimetic synthesis; carbonaceous biopreform; biomorphic Si–SiC ceramic composites; porous cellular SiC ceramics. 1. Introduction. In recent years, there has been tremendous ...

  9. Use of ultra-filtration in organic-rich groundwater for the physical separation of thorium

    International Nuclear Information System (INIS)

    Singhal, R.K.; Basu, H.; Pimple, M.V.; Manisha, V.; Bassan, M.K.T.; Reddy, A.V.R.

    2014-01-01

    During this work, size fractionation technique 'ultra filtration' is used in physical speciation of thorium in organic rich groundwater. Laboratory simulated experiments were carried out to study the physical speciation of thorium in aquatic environment having elevated level of dissolved humus material classified as dissolved organic carbon (DOC). Samples were collected from organic rich environment having DOC in the range of 50-60 μg mL -1 . Th(IV) ions are extremely particle reactive having K d value of the order of 105-6, hence to avoid adsorption on suspended particulate matter, spiking of the solution with Th(NO 3 )4 was carried out in ground water samples after filtering through 450 nm pore size using suction filtration. Particles in dissolved state (colloids) ranging between 220 nm were separated using suction filtration assembly having a membrane with a pore diameter of 220 nm. Thereafter, solution was sequentially passed through the ultra-filtration membranes having pore diameters of 14 nm [300 k NMWL (nominal molecular weight limit)], 3.1 nm (50 k NMWL), 2.2 nm (30 k NMWL), 1.6 nm (10 k NMWL) and 1.1 nm (0.5 k NMWL) by using 'Stirred Ultra-filtration Cells', operating in concentration mode. Thorium has only one stable oxidation state i.e. IV, under all redox conditions in natural waters and therefore, its speciation is dominated by its interaction with various fractions of DOC. Experimental results show 50-60 % of the spiked Th is in association with fraction enriched with particles of 10 k NMWL (1.6 nm) followed by fraction enriched with particle of 0.5 k NMWL and <220 nm. (author)

  10. Tangential flow ultrafiltration for detection of white spot syndrome virus (WSSV) in shrimp pond water.

    Science.gov (United States)

    Alavandi, S V; Ananda Bharathi, R; Satheesh Kumar, S; Dineshkumar, N; Saravanakumar, C; Joseph Sahaya Rajan, J

    2015-06-15

    Water represents the most important component in the white spot syndrome virus (WSSV) transmission pathway in aquaculture, yet there is very little information. Detection of viruses in water is a challenge, since their counts will often be too low to be detected by available methods such as polymerase chain reaction (PCR). In order to overcome this difficulty, viruses in water have to be concentrated from large volumes of water prior to detection. In this study, a total of 19 water samples from aquaculture ecosystem comprising 3 creeks, 10 shrimp culture ponds, 3 shrimp broodstock tanks and 2 larval rearing tanks of shrimp hatcheries and a sample from a hatchery effluent treatment tank were subjected to concentration of viruses by ultrafiltration (UF) using tangential flow filtration (TFF). Twenty to 100l of water from these sources was concentrated to a final volume of 100mL (200-1000 fold). The efficiency of recovery of WSSV by TFF ranged from 7.5 to 89.61%. WSSV could be successfully detected by PCR in the viral concentrates obtained from water samples of three shrimp culture ponds, one each of the shrimp broodstock tank, larval rearing tank, and the shrimp hatchery effluent treatment tank with WSSV copy numbers ranging from 6 to 157mL(-1) by quantitative real time PCR. The ultrafiltration virus concentration technique enables efficient detection of shrimp viral pathogens in water from aquaculture facilities. It could be used as an important tool to understand the efficacy of biosecurity protocols adopted in the aquaculture facility and to carry out epidemiological investigations of aquatic viral pathogens. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Removal of trace organic chemicals and performance of a novel hybrid ultrafiltration-osmotic membrane bioreactor.

    Science.gov (United States)

    Holloway, Ryan W; Regnery, Julia; Nghiem, Long D; Cath, Tzahi Y

    2014-09-16

    A hybrid ultrafiltration-osmotic membrane bioreactor (UFO-MBR) was investigated for over 35 days for nutrient and trace organic chemical (TOrC) removal from municipal wastewater. The UFO-MBR system uses both ultrafiltration (UF) and forward osmosis (FO) membranes in parallel to simultaneously extract clean water from an activated sludge reactor for nonpotable (or environmental discharge) and potable reuse, respectively. In the FO stream, water is drawn by osmosis from activated sludge through an FO membrane into a draw solution (DS), which becomes diluted during the process. A reverse osmosis (RO) system is then used to reconcentrate the diluted DS and produce clean water suitable for direct potable reuse. The UF membrane extracts water, dissolved salts, and some nutrients from the system to prevent their accumulation in the activated sludge of the osmotic MBR. The UF permeate can be used for nonpotable reuse purposes (e.g., irrigation and toilet flushing). Results from UFO-MBR investigation illustrated that the chemical oxygen demand, total nitrogen, and total phosphorus removals were greater than 99%, 82%, and 99%, respectively. Twenty TOrCs were detected in the municipal wastewater that was used as feed to the UFO-MBR system. Among these 20 TOrCs, 15 were removed by the hybrid UFO-MBR system to below the detection limit. High FO membrane rejection was observed for all ionic and nonionic hydrophilic TOrCs and lower rejection was observed for nonionic hydrophobic TOrCs. With the exceptions of bisphenol A and DEET, all TOrCs that were detected in the DS were well rejected by the RO membrane. Overall, the UFO-MBR can operate sustainably and has the potential to be utilized for direct potable reuse applications.

  12. Fracture strength of three all-ceramic systems: Top-Ceram compared with IPS-Empress and In-Ceram.

    Science.gov (United States)

    Quran, Firas Al; Haj-Ali, Reem

    2012-03-01

    The purpose of this study was to investigate the fracture loads and mode of failure of all-ceramic crowns fabricated using Top-Ceram and compare it with all-ceramic crowns fabricated from well-established systems: IPS-Empress II, In-Ceram. Thirty all-ceramic crowns were fabricated; 10 IPS-Empress II, 10 In-Ceram alumina and 10 Top-Ceram. Instron testing machine was used to measure the loads required to introduce fracture of each crown. Mean fracture load for In-Ceram alumina [941.8 (± 221.66) N] was significantly (p > 0.05) higher than those of Top-Ceram and IPS-Empress II. There was no statistically significant difference between Top-Ceram and IPS-Empress II mean fracture loads; 696.20 (+222.20) and 534 (+110.84) N respectively. Core fracture pattern was highest seen in Top- Ceram specimens.

  13. Influence of implant abutment material on the color of different ceramic crown systems.

    Science.gov (United States)

    Dede, Doğu Ömür; Armağanci, Arzu; Ceylan, Gözlem; Celik, Ersan; Cankaya, Soner; Yilmaz, Burak

    2016-11-01

    Ceramics are widely used for anterior restorations; however, clinical color reproduction still constitutes a challenge particularly when the ceramic crowns are used on titanium implant abutments. The purpose of this in vitro study was to investigate the effect of implant abutment material on the color of different ceramic material systems. Forty disks (11×1.5 mm, shade A2) were fabricated from medium-opacity (mo) and high-translucency (ht) lithium disilicate (IPS e.max) blocks, an aluminous ceramic (VITA In-Ceram Alumina), and a zirconia (Zirkonzahn) ceramic system. Disks were fabricated to represent 3 different implant abutments (zirconia, gold-palladium, and titanium) and dentin (composite resin, A2 shade) as background (11×2 mm). Disk-shaped composite resin specimens in A2 shade were fabricated to represent the cement layer. The color measurements of ceramic specimens were made on composite resin abutment materials using a spectrophotometer. CIELab color coordinates were recorded, and the color coordinates measured on composite resin background served as the control group. Color differences (ΔE 00 ) between the control and test groups were calculated. The data were analyzed with 2-way analysis of variance (ANOVA) and compared with the Tukey HSD test (α=.05). The ceramics system, abutment material, and their interaction were significant for ΔE 00 values (P2.25) were observed for lithium disilicate ceramics on titanium abutments (2.46-2.50). The ΔE 00 values of lithium disilicate ceramics for gold-palladium and titanium abutments were significantly higher than for other groups (P2.25) of an implant-supported lithium disilicate ceramic restoration may be clinically unacceptable if it is fabricated over a titanium abutment. Zirconia may be a more suitable abutment material for implant-supported ceramic restorations. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  14. Deodorant ceramic catalyst. Dasshu ceramics shokubai

    Energy Technology Data Exchange (ETDEWEB)

    Arai, K. (Kobe Steel Ltd., Kobe (Japan)); Naka, R. (Hitachi Ltd., Tokyo (Japan))

    1993-07-01

    Concerning debromination to be used for the filter of deodorizing device, those of long life and high deodorizing performance are demanded a great deal. As one of this kind of debromination, a deodorant ceramic catalyst (mangantid) has been developed and put for practical use as deodorant for refrigerator. In this article, the information and knowledge obtained by the development of mangantid, the features as well as several properties of the product are stated. The deodorizing methods currently used practically are roughly divided into 6 kinds such as the adsorption method, the direct combustion method, the catalytic method and the oxidation method, but each of them has its own merit and demerit, hence it is necessary to select the method in accordance with the kind of odor and its generating condition. Mangantid is a compound body of high deodorant material in a honeycomb configuration, and has the features that in comparison with the existing deordorants, its pressure loss is smaller, its deodorizing rate is bigger, and acidic, neutral and basic gaseous components can be removed in a well-balanced manner. Deodorization with mangantid has the mechanism to let the odorous component contact and react with the catalyst and change the component to the non-odorous component in the temperature range from room temperature to the low temperature region. 5 refs., 11 figs., 1 tab.

  15. Organic fouling behavior of superhydrophilic polyvinylidene fluoride (PVDF) ultrafiltration membranes functionalized with surface-tailored nanoparticles: Implications for organic fouling in membrane bioreactors

    KAUST Repository

    Liang, Shuai; Qi, Genggeng; Xiao, Kang; Sun, Jianyu; Giannelis, Emmanuel P.; Huang, Xia; Elimelech, Menachem

    2014-01-01

    This study systematically investigates the organic fouling behavior of a superhydrophilic polyvinylidene fluoride (PVDF) ultrafiltration membrane functionalized via post-fabrication tethering of surface-tailored silica nanoparticles to poly

  16. Influence of fertilizer draw solution properties on the process performance and microbial community structure in a side-stream anaerobic fertilizer-drawn forward osmosis – ultrafiltration bioreactor

    KAUST Repository

    Kim, Youngjin; Li, Sheng; Chekli, Laura; Phuntsho, Sherub; Ghaffour, NorEddine; Leiknes, TorOve; Shon, Ho Kyong

    2017-01-01

    In this study, a side-stream anaerobic fertilizer-drawn forward osmosis (FDFO) and ultrafiltration (UF) membrane bioreactor (MBR) hybrid system was proposed and operated for 55 days. The FDFO performance was first investigated in terms of flux

  17. Novel use of an ultrafiltration device as an alternative method for fluid removal in critically ill pediatric patients with cardiac disease: a case series

    Directory of Open Access Journals (Sweden)

    Sujata Chakravarti

    2016-06-01

    Full Text Available Fluid overload (FO is a common complication for pediatric patients in the intensive care unit. When conventional therapy fails, hemodialysis or peritoneal dialysis is classically used for fluid removal. Unfortunately, these therapies are often associated with cardiovascular or respiratory instability. Ultrafiltration, using devices such as the AquadexTM system (Baxter Healthcare, Deerfield, IL, USA, is an effective tool for fluid removal in adult patients with congestive heart failure. As compared to hemodialysis, ultrafiltration can be performed using smaller catheters, and the extracorporeal volume and minimal blood flow rates are lower. In addition, there is no associated abdominal distension as is seen in peritoneal dialysis. Consequently, ultrafiltration may be better tolerated in critically ill pediatric patients. We present three cases of challenging pediatric patients with FO in the setting of congenital heart disease in whom ultrafiltration using the AquadexTM system was successfully utilized for fluid removal while cardiorespiratory stability was maintained.

  18. A Modified EPA Method 1623 that Uses Tangential Flow Hollow-Fiber Ultrafiltration and Heat Dissociation Steps to Detect Waterborne Cryptosporidum and Giardia spp.

    Science.gov (United States)

    This protocol describes the use of a tangential flow hollow-fiber ultrafiltration sample concentration system and a heat dissociation as alternative steps for the detection of waterborne Cryptosporidium and Giardia species using EPA Method 1623.

  19. Micromolding for ceramic microneedle arrays

    NARCIS (Netherlands)

    van Nieuwkasteele-Bystrova, Svetlana Nikolajevna; Lüttge, Regina

    2011-01-01

    The fabrication process of ceramic microneedle arrays (MNAs) is presented. This includes the manufacturing of an SU-8/Si-master, its double replication resulting in a PDMS mold for production by micromolding and ceramic sintering. The robustness of the replicated structures was tested by means of

  20. Ceramics in nuclear waste management

    Energy Technology Data Exchange (ETDEWEB)

    Chikalla, T D; Mendel, J E [eds.

    1979-05-01

    Seventy-three papers are included, arranged under the following section headings: national programs for the disposal of radioactive wastes, waste from stability and characterization, glass processing, ceramic processing, ceramic and glass processing, leaching of waste materials, properties of nuclear waste forms, and immobilization of special radioactive wastes. Separate abstracts were prepared for all the papers. (DLC)

  1. Science and Technology of Ceramics

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 12. Science and Technology of Ceramics - Functional Ceramics. Sheela K Ramasesha. Series Article Volume 4 Issue 12 December 1999 pp 21-30. Fulltext. Click here to view fulltext PDF. Permanent link:

  2. Science and Technology of Ceramics

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 8. Science and Technology of Ceramics - Traditional Ceramics. Sheela K Ramasesha. Series Article Volume 4 Issue 8 August 1999 pp 16-24. Fulltext. Click here to view fulltext PDF. Permanent link:

  3. CRYSTALLINE CERAMIC WASTE FORMS: REFERENCE FORMULATION REPORT

    Energy Technology Data Exchange (ETDEWEB)

    Brinkman, K.; Fox, K.; Marra, J.

    2012-05-15

    The research conducted in this work package is aimed at taking advantage of the long term thermodynamic stability of crystalline ceramics to create more durable waste forms (as compared to high level waste glass) in order to reduce the reliance on engineered and natural barrier systems. Durable ceramic waste forms that incorporate a wide range of radionuclides have the potential to broaden the available disposal options and to lower the storage and disposal costs associated with advanced fuel cycles. Assemblages of several titanate phases have been successfully demonstrated to incorporate radioactive waste elements, and the multiphase nature of these materials allows them to accommodate variation in the waste composition. Recent work has shown that they can be successfully produced from a melting and crystallization process. The objective of this report is to explain the design of ceramic host systems culminating in a reference ceramic formulation for use in subsequent studies on process optimization and melt property data assessment in support of FY13 melter demonstration testing. The waste stream used as the basis for the development and testing is a combination of the projected Cs/Sr separated stream, the Trivalent Actinide - Lanthanide Separation by Phosphorous reagent Extraction from Aqueous Komplexes (TALSPEAK) waste stream consisting of lanthanide fission products, the transition metal fission product waste stream resulting from the transuranic extraction (TRUEX) process, and a high molybdenum concentration with relatively low noble metal concentrations. In addition to the combined CS/LN/TM High Mo waste stream, variants without Mo and without Mo and Zr were also evaluated. Based on the results of fabricating and characterizing several simulated ceramic waste forms, two reference ceramic waste form compositions are recommended in this report. The first composition targets the CS/LN/TM combined waste stream with and without Mo. The second composition targets

  4. CAD/CAM glass ceramics for single-tooth implant crowns: a finite element analysis.

    Science.gov (United States)

    Akça, Kvanç; Cavusoglu, Yeliz; Sagirkaya, Elcin; Aybar, Buket; Cehreli, Murat Cavit

    2013-12-01

    To evaluate the load distribution of CAD/CAM mono-ceramic crowns supported with single-tooth implants in functional area. A 3-dimensional numerical model of a soft tissue-level implant was constructed with cement-retained abutment to support glass ceramic machinable crown. Implant-abutment complex and the retained crown were embedded in a Ø 1.5 × 1.5 cm geometric matrix for evaluation of mechanical behavior of mono-ceramic CAD/CAM aluminosilicate and leucite glass crown materials. Laterally positioned axial load of 300 N was applied on the crowns. Resulting principal stresses in the mono-ceramic crowns were evaluated in relation to different glass ceramic materials. The highest compressive stresses were observed at the cervical region of the buccal aspect of the crowns and were 89.98 and 89.99 MPa, for aluminosilicate and leucite glass ceramics, respectively. The highest tensile stresses were observed at the collar of the lingual part of the crowns and were 24.54 and 25.39 MPa, respectively. Stresses induced upon 300 N static loading of CAD/CAM aluminosalicate and leucite glass ceramics are below the compressive strength of the materials. Impact loads may actuate the progress to end failure of mono-ceramic crowns supported by metallic implant abutments.

  5. Studies for the use of water soluble chelating polymer in ultra-filtration technique for the removal of uranium from aqueous solutions

    International Nuclear Information System (INIS)

    Misra, S.K.; Mahatele, A.K.; Tripathi, S.C.; Vijayan, K.; Munshi, S.K.

    2005-01-01

    Studies were carried out for the removal of uranium from aqueous medium using water soluble chelating polymer by ultra-filtration technique. The water soluble polymers are the option for the surfactants used in the micellar enhanced ultra-filtration technique. More than 95% separation of uranium carried out under different experimental conditions, suggest that the technique can be effectively employed for the removal uranium from the aqueous effluent streams. (author)

  6. Low thermal expansion glass ceramics

    CERN Document Server

    1995-01-01

    This book is one of a series reporting on international research and development activities conducted by the Schott group of companies With the series, Schott aims to provide an overview of its activities for scientists, engineers, and managers from all branches of industry worldwide where glasses and glass ceramics are of interest Each volume begins with a chapter providing a general idea of the current problems, results, and trends relating to the subjects treated This volume describes the fundamental principles, the manufacturing process, and applications of low thermal expansion glass ceramics The composition, structure, and stability of polycrystalline materials having a low thermal expansion are described, and it is shown how low thermal expansion glass ceramics can be manufactured from appropriately chosen glass compositions Examples illustrate the formation of this type of glass ceramic by utilizing normal production processes together with controlled crystallization Thus glass ceramics with thermal c...

  7. Method of forming a ceramic matrix composite and a ceramic matrix component

    Science.gov (United States)

    de Diego, Peter; Zhang, James

    2017-05-30

    A method of forming a ceramic matrix composite component includes providing a formed ceramic member having a cavity, filling at least a portion of the cavity with a ceramic foam. The ceramic foam is deposited on a barrier layer covering at least one internal passage of the cavity. The method includes processing the formed ceramic member and ceramic foam to obtain a ceramic matrix composite component. Also provided is a method of forming a ceramic matrix composite blade and a ceramic matrix composite component.

  8. Process and device for forming imprints on ceramic tubes

    International Nuclear Information System (INIS)

    1985-01-01

    The purpose of the present invention is a process and a device for making imprints on ceramic tubes and these ceramic tubes with imprints. It is known that in uranium enrichment processes by gaseous diffusion, microporous tubes are used to made the diffuser units used for the application of this isotope enrichment process. It is known that these microporous tubes are generally made in two stages. In a first stage, a macroporous ceramic tube called a ''support'' is made. In a second stage, an internal microporous deposit is made which makes it possible to obtain a tube called a ''barrier'' finally having the required porosity to apply the gaseous diffusion enrichment process. The present invention involves the first stage of the manufacturing process of the barriers and, more precisely, a step in the manufacturing process of the supports that makes it possible to improve the efficiency of these barriers

  9. Zirconia based ceramics

    International Nuclear Information System (INIS)

    Bressiani, J.C.; Bressiani, A.H.A.

    1989-05-01

    Within the new generation of ceramic materials, zirconia continues to attract ever increasing attention of scients, technologists and users by virtue of its singular combination of properties and being able to perform thermo-mechanical, electroeletronic, chemico-biological functions. Nevertheless, in order to obtain these properties, a through understanding of the phase transformation mechanisms and microstructural changes is necessary. This paper discusses the main parameters that require control during fabrication of these materials to obtain desired properties for a specific application. (author) [pt

  10. Directionally Solidified Multifunctional Ceramics

    Science.gov (United States)

    2006-12-01

    Vidrio , Vol. 44 [5] (2005) pp 347 - 352. 9. F. W. Dynys and A. Sayir, "Self Assemble Silicide Architectures by Directional Solidification," Journal...Sociedad Espanola de Ceramica y Vidrio , Vol. 43 [4] (2004) pp 753 - 758. 21. A. Sayir and F. S. Lowery, "Combustion-Resistance of Silicon-Based Ceramics...Espafiola de Cerdmica y Vidrio , Vol. 43 [3], 2004. ISSN-0366-3175-BSCVB9. 14 37. P. Berger, A. Sayir and M. H. Berger, "Nuclear Microprobe using Elastic

  11. Formulation and synthesis by melting process of titanate enriched glass-ceramics and ceramics

    International Nuclear Information System (INIS)

    Advocat, T.; Fillet, C.; Lacombe, J.; Bonnetier, A.; McGlinn, P.

    1999-01-01

    The main objective of this work is to provide containment for the separated radionuclides in stable oxide phases with proven resistance to leaching and irradiation damage and in consequence to obtain a glass ceramic or a ceramic material using a vitrification process. Sphene glass ceramic, zirconolite glass ceramic and zirconolite enriched ceramic have been fabricated and characterized by XRD, SEM/EDX and DTA

  12. Non-woven PET fabric reinforced and enhanced the performance of ultrafiltration membranes composed of PVDF blended with PVDF-g-PEGMA for industrial applications

    Science.gov (United States)

    Wang, Shuai; Li, Tong; Chen, Chen; Chen, Sheng; Liu, Baicang; Crittenden, John

    2018-03-01

    Ultrafiltration (UF) membranes composed of poly(vinylidene fluoride) (PVDF) blended with poly(vinylidene fluoride)-graft-poly(ethylene glycol) methyl ether methacrylate (PVDF-g-PEGMA) can present high flux and excellent foulant removal efficiencies under suitable preparation conditions. However, these PVDF/PVDF-g-PEGMA blended membranes cannot be applied industrially because of the insufficient mechanical strength (strength-to-break value of 8.4 ± 0.6 MPa). We incorporated two types of non-woven polyethylene terephthalate (PET) fabrics (thin hydrophobic and thick hydrophilic fabrics) as support layers to improve the mechanical properties of the blended membranes. The thin and thick PET fabrics were able to significantly improve the tensile strength to 23.3 ± 3.7 MPa and 30.1 ± 1.4 MPa, respectively. The PET fabrics had a limited impact on the separation-related membrane performance such as hydrophilicity, foulant rejection, whereas the mechanical strength and pure water flux was improved several folds. The enhanced flux was attributed to the higher surface porosity and wider finger-like voids in the cross-section. The thin PET fabric with larger porosity was able to maintain a consistent toughness simultaneously; thus it is recommended as a support material for this blended membrane.

  13. Nano-ceramics and its molding technologies

    International Nuclear Information System (INIS)

    Liu Jian; Xu Yunshu

    2007-01-01

    Nano-ceramics and its related knowledge were introduced. Fabrication of nano-ceramic powder, as well as the molding and sintering technologies of nano-ceramics were reviewed. Features of the present molding technologies were analyzed. The applications of nano-ceramics were prospected. (authors)

  14. Preparation of 147Pm ceramic source core

    International Nuclear Information System (INIS)

    Mielcarski, M.

    1989-01-01

    Preparation of ceramic pellets containing fixed promethium-147 is described. Incorporation rate of 147 Pm into the ceramic material was determined. The leachability and vaporization of promethium from the obtained ceramics was investigated. The ceramic pellets prepared by the described procedure, mounted in special holders, can be applied as point sources in beta backscatter thickness gauges. (author)

  15. Study of the binding of {sup 114m}In radiotracer to human serum components by ultrafiltration and chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Hulle, M. van; De Cremer, K.; Cornelis, R. [Ghent Rijksuniversiteit (Belgium). Lab. for Analytical Chemistry

    2000-10-01

    The chemical speciation of indium in serum was studied. Ultrafiltration was used to investigate the influence of several buffer systems on the binding characteristics of indium in serum and to study the association of indium with transferrin and albumin. This was performed by means of batch incubation experiments with a {sup 114m}In tracer. Different buffer systems were investigated. A series of bicarbonate, Tris:HCl and HEPES buffers were found to fit for this purpose. Phosphate buffer was not suitable, as it is capable of disrupting the binding between indium and transferrin. Batch ultrafiltration experiments with {sup 114m}In incubated solutions of transferrin and albumin showed that both proteins are capable of binding indium to a high degree. Three chromatographic techniques (SEC, AEC, AC) were used to study the different chemically active species of indium in serum. It is concluded that next to transferrin, albumin is also responsible for the binding and transport of indium in serum. (orig.)

  16. Enhanced permeability and antifouling performance of cellulose acetate ultrafiltration membrane assisted by l-DOPA functionalized halloysite nanotubes.

    Science.gov (United States)

    Mu, Keguang; Zhang, Dalun; Shao, Ziqiang; Qin, Dujian; Wang, Yalong; Wang, Shuo

    2017-10-15

    l-Dopa functionalized halloysite nanotubes (HNTs) were prepared by the self-polymerization of l-dopa in the weak alkaline condition. Then different contents of l-dopa coated HNTs (LPDHNTs) were blended into cellulose acetate to prepare enhanced performance ultrafiltration membranes via the phase inversion method. The HNTs and LPDHNTs were characterized by FTIR, XPS, and TEM anysis. And the membranes morphologies, separation performance, antifouling performance, mechanical properties and hydrophilicity were also investigated. It was found that the composite membranes exhibited excellent antifouling performance. The pure water flux of 3.0wt% LPDHNTs/CA membrane increased from 11.4Lm -2 h -1 to 92.9Lm -2 h -1 , while the EA rejection ratio of the membrane was about 91.2%. In addition, the mechanical properties of the resultant membranes were strengthened compared with the CA ultrafiltration membrane. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Ultrafiltration and thermal processing effects on Maillard reaction products and biological properties of date palm sap syrups (Phoenix dactylifera L.).

    Science.gov (United States)

    Makhlouf-Gafsi, Ines; Krichen, Fatma; Mansour, Riadh Ben; Mokni, Abir; Sila, Assad; Bougatef, Ali; Blecker, Christophe; Attia, Hamadi; Besbes, Souhail

    2018-08-01

    The effect of ultrafiltration process and temperature concentration on MRPs content and antioxidant, antimicrobial and cytotoxic properties of date palm sap syrups were investigated. MRPs were analyzed by HPLC. Antioxidant activity was evaluated by reducing power and DPPH free radical and H 2 O 2 scavenging activities. Antimicrobial activity was evaluated by the agar disk diffusion method. In vitro cytotoxic activity was examined by cell proliferation assay. Date sap syrups displayed strong antioxidant activities which are correlated 5HMF and 2F contents. In addition, concentration at 100 °C, unlike ultrafiltration process, enhanced significantly the antioxidant activities sap syrups and total phenolic contents. The antimicrobial activities showed marked activity against S. enterica, P. aeruginosa, S. aureus, L. monocytogenes with an inhibition zone of 21, 34, 27 and 34 mm respectively. Cytotoxicity assays showed that sap syrups can inhibit the proliferation of HeLa cell lines at high concentration. Published by Elsevier Ltd.

  18. Development of High-Antifouling PPSU Ultrafiltration Membrane by Using Compound Additives: Preparation, Morphologies, and Filtration Resistant Properties

    OpenAIRE

    Jie Liu; Zhencheng Zhong; Rui Ma; Weichen Zhang; Jiding Li

    2016-01-01

    In this study, flat sheet asymmetric polyphenylsulfone (PPSU) ultrafiltration membranes with enhanced antifouling properties were prepared with a non-solvent induced phase separation (NIPS) method through compound additives containing a polymeric pore-forming agent, a small molecular non-solvent and a surfactant. The formation processes of the porous asymmetric membranes with different kinds of additives were studied in detail, and the microstructure controllable preparation of membrane was a...

  19. Fabrication of TiO{sub 2}-modified polytetrafluoroethylene ultrafiltration membranes via plasma-enhanced surface graft pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Yingjia [School of Environmental Science and Engineering, Shanghai Jiaotong University, Shanghai 200240 (China); Chi, Lina, E-mail: lnchi@sjtu.edu.cn [School of Environmental Science and Engineering, Shanghai Jiaotong University, Shanghai 200240 (China); Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ (United Kingdom); Zhou, Weili; Yu, Zhenjiang [School of Environmental Science and Engineering, Shanghai Jiaotong University, Shanghai 200240 (China); Zhang, Zhongzhi [College of Chemical Engineering, China University of Petroleum, Beijing 102249 (China); Zhang, Zhenjia [School of Environmental Science and Engineering, Shanghai Jiaotong University, Shanghai 200240 (China); Jiang, Zheng, E-mail: z.jiang@soton.ac.uk [Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ (United Kingdom)

    2016-01-01

    Graphical abstract: - Highlights: • Multifunctional TiO{sub 2}/PAA/PTFE ultrafiltration membrane was fabricated via tight coating of TiO{sub 2} functional layer onto the plasma-assisted graft of PAA on PTFE. • The high water flux rate, remarkable enhanced ultrafiltration performance and excellent self-cleaning ability were demonstrated. • The formation of COO−Ti bidentate coordination between TiO{sub 2} and PAA was responsible for the successful coating. - Abstract: Surface hydrophilic modification of polymer ultrafiltration membrane using metal oxide represents an effective yet highly challenging solution to improve water flux and antifouling performance. Via plasma-enhanced graft of poly acryl acid (PAA) prior to coating TiO{sub 2}, we successfully fixed TiO{sub 2} functional thin layer on super hydrophobic polytetrafluoroethylene (PTFE) ultrafiltration (UF) membranes. The characterization results evidenced TiO{sub 2} attached on the PTFE-based UF membranes through the chelating bidentate coordination between surface-grafted carboxyl group and Ti{sup 4+}. The TiO{sub 2} surface modification may greatly reduce the water contact angle from 115.8° of the PTFE membrane to 35.0° without degradation in 30-day continuous filtration operations. The novel TiO{sub 2}/PAA/PTFE membranes also exhibited excellent antifouling and self-cleaning performance due to the intrinsic hydrophilicity and photocatalysis properties of TiO{sub 2}, which was further confirmed by the photo-degradation of MB under Xe lamp irradiation.

  20. Fibrous monolithic ceramics

    International Nuclear Information System (INIS)

    Kovar, D.; King, B.H.; Trice, R.W.; Halloran, J.W.

    1997-01-01

    Fibrous monolithic ceramics are an example of a laminate in which a controlled, three-dimensional structure has been introduced on a submillimeter scale. This unique structure allows this all-ceramic material to fail in a nonbrittle manner. Materials have been fabricated and tested with a variety of architectures. The influence on mechanical properties at room temperature and at high temperature of the structure of the constituent phases and the architecture in which they are arranged are discussed. The elastic properties of these materials can be effectively predicted using existing models. These models also can be extended to predict the strength of fibrous monoliths with an arbitrary orientation and architecture. However, the mechanisms that govern the energy absorption capacity of fibrous monoliths are unique, and experimental results do not follow existing models. Energy dissipation occurs through two dominant mechanisms--delamination of the weak interphases and then frictional sliding after cracking occurs. The properties of the constituent phases that maximize energy absorption are discussed. In this article, the authors examine the structure of Si 3 N 4 -BN fibrous monoliths from the submillimeter scale of the crack-deflecting cell-cell boundary features to the nanometer scale of the BN cell boundaries

  1. Ceramic fiber reinforced filter

    Science.gov (United States)

    Stinton, David P.; McLaughlin, Jerry C.; Lowden, Richard A.

    1991-01-01

    A filter for removing particulate matter from high temperature flowing fluids, and in particular gases, that is reinforced with ceramic fibers. The filter has a ceramic base fiber material in the form of a fabric, felt, paper of the like, with the refractory fibers thereof coated with a thin layer of a protective and bonding refractory applied by chemical vapor deposition techniques. This coating causes each fiber to be physically joined to adjoining fibers so as to prevent movement of the fibers during use and to increase the strength and toughness of the composite filter. Further, the coating can be selected to minimize any reactions between the constituents of the fluids and the fibers. A description is given of the formation of a composite filter using a felt preform of commercial silicon carbide fibers together with the coating of these fibers with pure silicon carbide. Filter efficiency approaching 100% has been demonstrated with these filters. The fiber base material is alternately made from aluminosilicate fibers, zirconia fibers and alumina fibers. Coating with Al.sub.2 O.sub.3 is also described. Advanced configurations for the composite filter are suggested.

  2. Morphology and performance of polyvinylidene fluoride/perfluoro sulphonic acid hollow fiber ultrafiltration blend membranes

    International Nuclear Information System (INIS)

    Yuan, Guo-Lin; Xu, Zhen-Liang; Wei, Yong-Ming; Yu, Li-Yun

    2009-01-01

    Polyvinylidene fluoride-perfluoro sulphonic acid hollow fibre ultrafiltration blend membranes were prepared by wet-spinning method. Polyvinylpyrrolidone and ethanol aqueous solutions were employed as additive and coagulants, respectively. The effect of Polyvinylpyrrolidone concentration in the dopes and ethanol concentration in the coagulants on morphology and performance of Polyvinylidene fluoride -perfluoro sulphonic acid hollow fibre ultrafiltration blend membranes were investigated. Blend membranes were characterized in terms of precipitation kinetics, morphology, thermal property and separation performance. The results showed that the increments of Polyvinylpyrrolidone concentration in the dopes and ethanol concentration in coagulants both resulted in higher pure water permeation flux and worse rejection (R) of bovine serum albumin (with the increment of Polyvinylpyrrolidone concentration from 0 to 5 wt% in the dopes, pure water permeation increased from 41.7 L.m -2 .h -1 to 134 L.m -2 .h -1 and R decreased from 99.8% to 84.4% as well as with the increase in ethanol concentration in coagulants from 0 to 40 wt%, pure water permeation increased from 33.5 L.m -2 .h- 1 to 123 L.m -2 .h -1 and R decreased from 97.7% to 88.7%). However, the proportion of sponge-like structure in the cross-section of membranes decreased with the increasing Polyvinylpyrrolidone concentration in the dopes and the proportion increased with the increased ethanol concentration in the coagulations. In addition, the location of the sponge-like structure in the cross-section of membranes was significantly influenced by ethanol concentrations in the coagulants and differential scanning calorimeter results revealed that the crystallinity (X c ) of the blend membrane was in accordance with the proportion of sponge-like structure. These behaviours were attributed to the different roles of Polyvinylpyrrolidone in the dopes and ethanol in the coagulants, respectively. Polyvinylidene fluoride

  3. Effect of skim milk treated with high hydrostatic pressure on permeate flux and fouling during ultrafiltration.

    Science.gov (United States)

    Leu, Mathilde; Marciniak, Alice; Chamberland, Julien; Pouliot, Yves; Bazinet, Laurent; Doyen, Alain

    2017-09-01

    Ultrafiltration (UF) is largely used in the dairy industry to generate milk and whey protein concentrate for standardization of milk or production of dairy ingredients. Recently, it was demonstrated that high hydrostatic pressure (HHP) extended the shelf life of milk and improved rennet coagulation and cheese yield. Pressurization also modified casein micelle size distribution and promoted aggregation of whey proteins. These changes are likely to affect UF performance. Consequently, this study determined the effect of skim milk pressurization (300 and 600 MPa, 5 min) on UF performance in terms of permeate flux decline and fouling. The effect of HHP on milk proteins was first studied and UF was performed in total recycle mode at different transmembrane pressures to determine optimal UF operational parameters and to evaluate the effect of pressurization on critical and limiting fluxes. Ultrafiltration was also performed in concentration mode at a transmembrane pressure of 345 kPa for 130 or 140 min to evaluate the decline of permeate flux and to determine fouling resistances. It was observed that average casein micelle size decreased by 32 and 38%, whereas β-lactoglobulin denaturation reached 30 and 70% at 300 and 600 MPa, respectively. These results were directly related to UF performance because initial permeate fluxes in total recycle mode decreased by 25% at 300 and 600 MPa compared with nonpressurized milk, critical flux, and limiting flux, which were lower during UF of milk treated with HHP. During UF in concentration mode, initial permeate fluxes were 30% lower at 300 and 600 MPa compared with the control, but the total flux decline was higher for nonpressurized milk (62%) compared with pressure-treated milk (30%). Fouling resistances were similar, whatever the treatment, except at 600 MPa where irreversible fouling was higher. Characterization of the fouling layer showed that caseins and β-lactoglobulin were mainly involved in membrane fouling after UF of

  4. Investigação sobre a eficiência da fibra de vidro e da fibra cerâmica como suporte de solda na soldagem unilateral Investigation over the eficiency of fiber glass and ceramic fiber as weld support in one-sided welding

    Directory of Open Access Journals (Sweden)

    Luiz Cláudio Tatagiba

    2011-12-01

    Full Text Available O objetivo deste trabalho foi avaliar uma nova categoria de suporte de solda para a soldagem unilateral do aço carbono, usando tecidos de fibra de vidro e fibra cerâmica. Trata-se de uma proposta de inovação tecnológica, uma evolução do suporte cerâmico convencional. A soldagem unilateral com este tipo de suporte de solda foi executada em chapas de aço carbono com arame tubular (FCAW e MIG-MAG (GMAW. A eficiência da fibra de vidro e da fibra cerâmica em suportar o metal de solda líquido foi verificada durante a soldagem do passe de raiz. Várias espessuras e combinações de tecidos de fibra de vidro e fibra cerâmica foram testadas, bem como foram identificados pontos de trabalho. As seguintes variáveis do processo foram estudadas: a abertura de raiz, a corrente e a velocidade de soldagem. Os resultados mostram que os materiais à base de fibra de vidro e fibra cerâmica são eficientes para suportar a poça de solda líquida. O modo de fixação do suporte de solda na junta soldada também mostrou ser efetivo. Foi possível estimar uma faixa de operação do processo, com abertura de raiz de 2,0 a 4,0 mm, a energia de soldagem menor que 1,8 kJ/mm, a técnica de soldagem ligeiramente puxando e com pequena oscilação da tocha, espessura do suporte de solda de tecido de fibra de vidro maior que 1,6 mm. Macrogafias da juntas soldadas mostraram que houve penetração nas laterais do chanfro, reforço de solda adequado na raiz e não foram notados defeitos.The objective of this work was to evaluate a new chategory of weld support for the one-sided welding of carbon steel, using fiber glass and ceramic fiber tissues. This is a proposal of techonological innovation proposed, an evolution of the conventional ceramic support. The one-sided welding with this type of weld support was made in carbon steel with FCAW and GMAW. The efficiency of fiber glass and ceramic fiber was verified during the root weld bead. Several thicknesses and

  5. Ceramic drug-delivery devices.

    Science.gov (United States)

    Lasserre, A; Bajpai, P K

    1998-01-01

    A variety of ceramics and delivery systems have been used to deliver chemicals, biologicals, and drugs at various rates for desired periods of time from different sites of implantation. In vitro and in vivo studies have shown that ceramics can successfully be used as drug-delivery devices. Matrices, inserts, reservoirs, cements, and particles have been used to deliver a large variety of therapeutic agents such as antibiotics, anticancer drugs, anticoagulants, analgesics, growth factors, hormones, steroids, and vaccines. In this article, the advantages and disadvantages of conventional drug-delivery systems and the different approaches used to deliver chemical and biological agents by means of ceramic systems will be reviewed.

  6. High flow ceramic pot filters

    OpenAIRE

    van Halem, D.; van der Laan, H.; Soppe, A. I.A.; Heijman, S.G.J.

    2017-01-01

    Ceramic pot filters are considered safe, robust and appropriate technologies, but there is a general consensus that water revenues are limited due to clogging of the ceramic element. The objective of this study was to investigate the potential of high flow ceramic pot filters to produce more water without sacrificing their microbial removal efficacy. High flow pot filters, produced by increasing the rice husk content, had a higher initial flow rate (6–19 L h−1), but initial LRVs for E. coli o...

  7. Hardness of ion implanted ceramics

    International Nuclear Information System (INIS)

    Oliver, W.C.; McHargue, C.J.; Farlow, G.C.; White, C.W.

    1985-01-01

    It has been established that the wear behavior of ceramic materials can be modified through ion implantation. Studies have been done to characterize the effect of implantation on the structure and composition of ceramic surfaces. To understand how these changes affect the wear properties of the ceramic, other mechanical properties must be measured. To accomplish this, a commercially available ultra low load hardness tester has been used to characterize Al 2 O 3 with different implanted species and doses. The hardness of the base material is compared with the highly damaged crystalline state as well as the amorphous material

  8. Porous ceramics out of oxides

    International Nuclear Information System (INIS)

    Bakunov, V.S.; Balkevich, V.L.; Vlasov, A.S.; Guzman, I.Ya.; Lukin, E.S.; Poluboyarinov, D.N.; Poliskij, R.Ya.

    1977-01-01

    A review is made of manufacturing procedures and properties of oxide ceramics intended for high-temperature thermal insulation and thermal protection applications. Presented are structural characteristics of porous oxide refractories and their properties. Strength and thermal conductivity was shown to depend upon porosity. Described is a procedure for manufacturing porous ceramic materials from aluminium oxide, zirconium dioxide, magnesium oxide, beryllium oxide. The thermal resistance of porous ceramics from BeO is considerably greater than that of other high-refractoriness oxides. Listed are areas of application for porous materials based on oxides

  9. Fabrication and scintillation performance of nonstoichiometric LuAG:Ce ceramics

    Czech Academy of Sciences Publication Activity Database

    Liu, S.; Feng, X.; Nikl, Martin; Wu, L.; Zhou, Z.; Li, J.; Kou, H.; Zeng, Y.; Shi, Y.; Pan, Y.

    2015-01-01

    Roč. 98, č. 2 (2015), s. 510-514 ISSN 0002-7820 Institutional support: RVO:68378271 Keywords : scintillator * ceramics * luminescence Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.787, year: 2015

  10. Immobilization of fission products in phosphate ceramic waste forms

    International Nuclear Information System (INIS)

    Singh, D.; Wagh, A.

    1997-01-01

    Argonne National Laboratory (ANL) is developing chemically bonded phosphate ceramics (CBPCs) to treat low-level mixed wastes, particularly those containing volatiles and pyrophorics that cannot be treated by conventional thermal processes. This work was begun under ANL''s Laboratory Directed Research and Development funds, followed by further development with support from EM-50''s Mixed Waste Focus Area

  11. Bond strength of plasma sprayed ceramic coatings on phosphate steels

    Czech Academy of Sciences Publication Activity Database

    Pokorný, P.; Mastný, L.; Sýkora, V.; Pala, Zdeněk; Brožek, Vlastimil

    2015-01-01

    Roč. 54, č. 2 (2015), s. 411-414 ISSN 0543-5846 R&D Projects: GA ČR(CZ) GAP108/12/1872 Institutional support: RVO:61389021 Keywords : phosphating * plasma spraying * ceramic coatings * corrosion * bond strength Subject RIV: CA - Inorganic Chemistry Impact factor: 0.959, year: 2014

  12. Tracheal ceramic rings for tracheomalacia: a review after 17 years.

    Science.gov (United States)

    Göbel, Gyula; Karaiskaki, Niki; Gerlinger, Imre; Mann, Wolf J

    2007-10-01

    Despite different support techniques, the surgical management of tracheomalacia is still a challenging problem. Satisfactory results after internal stenting are above 80%, whereas, when performing external stenting using biocompatible ceramic rings, results are reported at over 90%. The purpose of this study was to examine the efficiency of surgical treatment in patients with segmentary tracheomalacia using external ceramic ring grafts. In this retrospective study, we collected data from 12 patients who underwent surgery during the last 17 years for symptomatic segmentary tracheomalacia by use of biocompatible aluminum-oxide ceramic rings. All except one patient had undergone previous tracheostomy, six had a history of long-term intubation, two had previous trauma, and two patients had previous cancer treatment including radiotherapy. One of the patients still had an existing tracheostoma, which was closed when a ceramic ring was implanted. Tracheal wall collapse with pseudoglottis formation or flattened anterior-posterior tracheal diameter was documented with fiberoscopy at rest, and both pre- and postoperative airway resistance measurements were performed in all 12 patients using a spirometer. After malacic segments were found to be expandable using rigid tracheoscopy while the patient was under general anesthesia, preparation of the trachea was performed using a midline vertical incision in the neck. Subsequently, the malacic trachea was expanded by placing and suturing proper-sized ceramic ring(s) around it. In all patients, surgical expansion of the malacic segment using ceramic rings was successfully carried out without major complications while inspiratory stridor was resolved. Airway resistance decreased significantly from an average of 0.62 to 0.385 kPascal. Although the results of applying internal tracheal stents are encouraging, complications such as stent migration, granulation tissue and fistula formation, and mucociliary transport arrest are possible

  13. Proton-conducting cerate ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Pederson, L.R.; Coffey, G.W.; Bates, J.L.; Weber, W.J. [Pacific Northwest National Lab., Richland, WA (United States)

    1996-08-01

    Single-cell solid oxide fuel cells were constructed using strontium cerate as the electrolyte and their performance tested. Like certain zirconates, hafnates, and tantalates, the cerate perovskites are among a class of solid electrolytes that conduct protons at elevated temperatures. Depending on the temperature and chemical environment, these ceramics also support electronic and oxygen ion currents. A maximum power output of {approx}100 mW per cm{sup 2} electrolyte surface area was obtained at 900{degrees}C using 4% hydrogen as the fuel and air as the oxidant. A series of rare earth/ceria/zirconia were prepared and their electrical properties characterized. Rare earth dopants included ytterbia, yttria, terbia, and europia. Ionic conductivities were highest for rare earth/ceria and rare earth zirconia compositions; a minimum in ionic conductivity for all series were found for equimolar mixtures of ceria and zirconia. Cerium oxysulfide is of interest in fossil energy applications because of its high chemical stability and refractory nature. An alternative synthesis route to preparing cerium oxysulfide powders has been developed using combustion techniques.

  14. Reliability and Failure Modes of a Hybrid Ceramic Abutment Prototype.

    Science.gov (United States)

    Silva, Nelson Rfa; Teixeira, Hellen S; Silveira, Lucas M; Bonfante, Estevam A; Coelho, Paulo G; Thompson, Van P

    2018-01-01

    A ceramic and metal abutment prototype was fatigue tested to determine the probability of survival at various loads. Lithium disilicate CAD-milled abutments (n = 24) were cemented to titanium sleeve inserts and then screw attached to titanium fixtures. The assembly was then embedded at a 30° angle in polymethylmethacrylate. Each (n = 24) was restored with a resin-cemented machined lithium disilicate all-ceramic central incisor crown. Single load (lingual-incisal contact) to failure was determined for three specimens. Fatigue testing (n = 21) was conducted employing the step-stress method with lingual mouth motion loading. Failures were recorded, and reliability calculations were performed using proprietary software. Probability Weibull curves were calculated with 90% confidence bounds. Fracture modes were classified with a stereomicroscope, and representative samples imaged with scanning electron microscopy. Fatigue results indicated that the limiting factor in the current design is the fatigue strength of the abutment screw, where screw fracture often leads to failure of the abutment metal sleeve and/or cracking in the implant fixture. Reliability for completion of a mission at 200 N load for 50K cycles was 0.38 (0.52% to 0.25 90% CI) and for 100K cycles was only 0.12 (0.26 to 0.05)-only 12% predicted to survive. These results are similar to those from previous studies on metal to metal abutment/fixture systems where screw failure is a limitation. No ceramic crown or ceramic abutment initiated fractures occurred, supporting the research hypothesis. The limiting factor in performance was the screw failure in the metal-to-metal connection between the prototyped abutment and the fixture, indicating that this configuration should function clinically with no abutment ceramic complications. The combined ceramic with titanium sleeve abutment prototype performance was limited by the fatigue degradation of the abutment screw. In fatigue, no ceramic crown or ceramic

  15. Ceramic UO2 powder production at Cameco Corporation

    International Nuclear Information System (INIS)

    Mulligan, J.J.

    2005-01-01

    This paper describes the various aspects of ceramic grade UO 2 powder production at Cameco Corporation's Port Hope conversion facility. It discusses the significant safety systems, production processes and plant monitoring and control systems. It also provides an insight into how various support groups such as Quality Assurance, Analytical Services, and Technology Development contribute to the consistent production of high quality UO 2 powder. The ability of Cameco to identify, measure and control the physical and chemical properties of ceramic grade UO 2 has resulted in the production of uniform quality powder that has consistently met customer requirements. (author)

  16. Physical–chemical properties, separation performance, and fouling resistance of mixed-matrix ultrafiltration membranes

    KAUST Repository

    Hoek, Eric M.V.; Ghosh, Asim K.; Huang, Xiaofei; Liong, Monty; Zink, Jeffrey I.

    2011-01-01

    Herein we report on the formation and characterization of mixed-matrix ultrafiltration (UF) membranes hand-cast by nonsolvent induced phase inversion. We evaluated nanometer-to-micrometer sized inorganic fillers (silver, copper, silica, zeolite, and silver-zeolite) materials with polysulfone (PSf) as the polymeric dispersing matrix. In general, mixed-matrix membranes were rougher, more hydrophilic, and more mechanically robust. Only sub-micron zeolite-PSf mixed-matrix membranes exhibited simultaneous improvements in water permeability and solute selectivity; all other mixed-matrix membranes were more permeable, but less selective due to defects associated with poor polymer-filler binding. Protein and bacterial fouling resistance of mixed-matrix membranes containing silver, zeolite, and silver-zeolite nanoparticles were compared to a low-fouling, poly(acrylonitrile) (PAN) UF membrane. Zeolite and silver containing membranes exhibited better protein fouling resistance (due to higher hydrophilicity), whereas silver and silver-zeolite based membranes produce better bacterial fouling resistance due to antimicrobial properties. Overall, zeolite-PSf and silver exchanged zeolite-PSf membranes offered the best combination of improved permeability, selectivity, and fouling resistance - superior to the commercial PAN membrane. © 2011 Elsevier B.V.

  17. Ultrafiltration of thin stillage from conventional and e-mill dry grind processes.

    Science.gov (United States)

    Arora, Amit; Dien, Bruce S; Belyea, Ronald L; Wang, Ping; Singh, Vijay; Tumbleson, M E; Rausch, Kent D

    2011-05-01

    We used ultrafiltration (UF) to evaluate membrane filtration characteristics of thin stillage and determine solids and nutrient compositions of filtered streams. To obtain thin stillage, corn was fermented using laboratory methods. UF experiments were conducted in batch mode under constant temperature and flow rate conditions. Two regenerated cellulose membranes (10 and 100 kDa molecular weight cutoffs) were evaluated with the objective of retaining solids as well as maximizing permeate flux. Optimum pressures for 10 and 100 kDa membranes were 207 and 69 kPa, respectively. Total solids, ash, and neutral detergent fiber contents of input TS streams of dry grind and E-Mill processes were similar; however, fat and protein contents were different (p stillage fractionation had higher mean total solids contents (27.6% to 27.8%) compared to E-Mill (22.2% to 23.4%). Total solids in retentate streams were found similar to those from commercial evaporators used in industry (25% to 35% total solids). Fat contents of retentate streams ranged from 16.3% to 17.5% for the conventional process. A 2% increment in fat concentration was observed in the E-Mill retentate stream. Thin stillage ash content was reduced 60% in retentate streams.

  18. Nutrient recovery from the dry grind process using sequential micro and ultrafiltration of thin stillage.

    Science.gov (United States)

    Arora, Amit; Dien, Bruce S; Belyea, Ronald L; Singh, Vijay; Tumbleson, M E; Rausch, Kent D

    2010-06-01

    The effectiveness of microfiltration (MF) and ultrafiltration (UF) for nutrient recovery from a thin stillage stream was determined. When a stainless steel MF membrane (0.1microm pore size) was used, the content of solids increased from 7.0% to 22.8% with a mean permeate flux rate of 45L/m(2)/h (LMH), fat increased and ash content decreased. UF experiments were conducted in batch mode under constant temperature and flow rate conditions. Permeate flux profiles were evaluated for regenerated cellulose membranes (YM1, YM10 and YM100) with molecular weight cut offs of 1, 10 and 100kDa. UF increased total solids, protein and fat and decreased ash in retentate stream. When permeate streams from MF were subjected to UF, retentate total solids concentrations similar to those of commercial syrup (23-28.8%) were obtained. YM100 had the highest percent permeate flux decline (70% of initial flux) followed by YM10 and YM1 membranes. Sequential filtration improved permeate flux rates of the YM100 membrane (32.6-73.4LMH) but the percent decline was also highest in a sequential MF+YM100 system. Protein recovery was the highest in YM1 retentate. Removal of solids, protein and fat from thin stillage may generate a permeate stream that may improve water removal efficiency and increase water recycling. Copyright 2010 Elsevier Ltd. All rights reserved.

  19. Dynamic behaviour of river colloidal and dissolved organic matter through cross-flow ultrafiltration system.

    Science.gov (United States)

    Wilding, Andrew; Liu, Ruixia; Zhou, John L

    2005-07-01

    Through cross-flow filtration (CFF) with a 1-kDa regenerated cellulose Pellicon 2 module, the ultrafiltration characteristics of river organic matter from Longford Stream, UK, were investigated. The concentration of organic carbon (OC) in the retentate in the Longford Stream samples increased substantially with the concentration factor (cf), reaching approximately 40 mg/L at cf 15. The results of dissolved organic carbon (DOC) and colloidal organic carbon (COC) analysis, tracking the isolation of colloids from river waters, show that 2 mg/L of COC was present in those samples and good OC mass balance (77-101%) was achieved. Fluorescence measurements were carried out for the investigation of retentate and permeate behaviour of coloured dissolved organic materials (CDOM). The concentrations of CDOM in both the retentate and permeate increased with increasing cf, although CDOM were significantly more concentrated in the retentate. The permeation model expressing the correlation between log[CDOM] in the permeate and logcf was able to describe the permeation behaviour of CDOM in the river water with regression coefficients (r(2)) of 0.94 and 0.98. Dry weight analysis indicated that the levels of organic colloidal particles were from 49 to 71%, and between 29 and 51% of colloidal particles present were inorganic. COC as a percentage of DOC was found to be 10-16% for Longford Stream samples.

  20. Removal of radionuclides in drinking water by membrane treatment using ultrafiltration, reverse osmosis and electrodialysis reversal

    International Nuclear Information System (INIS)

    Montaña, M.; Camacho, A.; Serrano, I.; Devesa, R.; Matia, L.; Vallés, I.

    2013-01-01

    A pilot plant had been built to test the behaviour of ultrafiltration (UF), reverse osmosis (RO), and electrodialysis reversal (EDR) in order to improve the quality of the water supplied to Barcelona metropolitan area from the Llobregat River. This paper presents results from two studies to reduce natural radioactivity. The results from the pilot plant with four different scenarios were used to design the full-scale treatment plant built (SJD WTP). The samples taken at different steps of the treatment were analysed to determine gross alpha, gross beta and uranium activity. The results obtained revealed a significant improvement in the radiological water quality provided by both membrane techniques (RO and EDR showed removal rates higher than 60%). However, UF did not show any significant removal capacity for gross alpha, gross beta or uranium activities. RO was better at reducing the radiological parameters studied and this treatment was selected and applied at the full scale treatment plant. The RO treatment used at the SJD WTP reduced the concentration of both gross alpha and gross beta activities and also produced water of high quality with an average removal of 95% for gross alpha activity and almost 93% for gross beta activity at the treatment plant. -- Highlights: ► A study with a pilot plant using different membranes technologies was made. ► Big reduction on natural uranium and 40 K by reverse osmosis was found. ► Pilot plant and full-scale treatment plant behave similarly

  1. Removal of radionuclides in drinking water by membrane treatment using ultrafiltration, reverse osmosis and electrodialysis reversal.

    Science.gov (United States)

    Montaña, M; Camacho, A; Serrano, I; Devesa, R; Matia, L; Vallés, I

    2013-11-01

    A pilot plant had been built to test the behaviour of ultrafiltration (UF), reverse osmosis (RO), and electrodialysis reversal (EDR) in order to improve the quality of the water supplied to Barcelona metropolitan area from the Llobregat River. This paper presents results from two studies to reduce natural radioactivity. The results from the pilot plant with four different scenarios were used to design the full-scale treatment plant built (SJD WTP). The samples taken at different steps of the treatment were analysed to determine gross alpha, gross beta and uranium activity. The results obtained revealed a significant improvement in the radiological water quality provided by both membrane techniques (RO and EDR showed removal rates higher than 60%). However, UF did not show any significant removal capacity for gross alpha, gross beta or uranium activities. RO was better at reducing the radiological parameters studied and this treatment was selected and applied at the full scale treatment plant. The RO treatment used at the SJD WTP reduced the concentration of both gross alpha and gross beta activities and also produced water of high quality with an average removal of 95% for gross alpha activity and almost 93% for gross beta activity at the treatment plant. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Production and functional characterisation of antioxidative hydrolysates from corn protein via enzymatic hydrolysis and ultrafiltration.

    Science.gov (United States)

    Zhou, Kequan; Sun, Shi; Canning, Corene

    2012-12-01

    Corn protein was hydrolysed by three microbial proteases and further separated by sequential ultra-filtration to 12 hydrolysate fractions which were investigated for free radical scavenging capacity and chelating activity. The oxygen radical absorbance capacity (ORAC) of the hydrolysates varied significantly between 65.6 and 191.4μmoles Trolox equivalents (TE)/g dried weight with a small peptide fraction (NP-F3) produced by neutral protease (NP) possessing the highest antioxidant activity. The 1,1-diphenyl-2-picrylhydrazyl radical (DPPH()) scavenging activities of the hydrolysate fractions also varied significantly between 18.4 and 38.7μmoles TE/g. Two fractions (AP-F2 and AP-F3) produced by alkaline protease (AP) showed the strongest activity. However, no significant difference was detected on the chelating activity of the fractions. NP-F3, AP-F2, and AP-F3 were incorporated into ground beef to determine their effects on lipid oxidation during 15-day storage period. NP-F3 was the only fraction that inhibited lipid oxidation at both 250 and 500μg/g levels by as much as 52.9%. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Organic micro-pollutants’ removal via anaerobic membrane bioreactor with ultrafiltration and nanofiltration

    KAUST Repository

    Wei, Chunhai

    2015-12-15

    The removal of 15 organic micro-pollutants (OMPs) in synthetic municipal wastewater was investigated in a laboratory-scale mesophilic anaerobic membrane bioreactor (AnMBR) using ultrafiltration and AnMBR followed by nanofiltration (NF), where powdered activated carbon (PAC) was added to enhance OMPs removal. No significant effects of OMPs spiking and NF connection on bulk organics removal and biogas production were observed. Amitriptyline, diphenhydramine, fluoxetine, sulfamethoxazole, TDCPP and trimethoprim showed readily biodegradable characteristics with consistent biological removal over 80%. Atrazine, carbamazepine, DEET, Dilantin, primidone and TCEP showed refractory characteristics with biological removal below 40%. Acetaminophen, atenolol and caffeine showed a prolonged adaption time of around 45 d, with initial biological removal below 40% and up to 50-80% after this period. Most readily biodegradable OMPs contained a strong electron donating group. Most refractory OMPs contained a strong electron withdrawing group or a halogen substitute. NF showed consistent high rejection of 80-92% with an average of 87% for all OMPs, which resulted in higher OMPs removal in AnMBR-NF than in AnMBR alone, especially for refractory OMPs. Limited sorption performance of PAC for OMPs removal was mainly due to low and batch dosage (100 mg/L) as well as the competitive sorption caused by bulk organics.

  4. Comparison of acidic polymers for the removal of cobalt from water solutions by polymer assisted ultrafiltration

    Energy Technology Data Exchange (ETDEWEB)

    Dambies, Laurent, E-mail: chemjobs@netcourrir.com [Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw (Poland); Jaworska, Agnieszka, E-mail: a.jaworska@ichtj.waw.pl [Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw (Poland); Zakrzewska-Trznadel, Grazyna; Sartowska, Bozena [Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw (Poland)

    2010-06-15

    In this study, three sulfonated water-soluble polymers based on poly(vinyl alcohol) of different molecular weights (10,000, 50,000 and 100,000 Da) were prepared and tested against commercially available poly(acrylic acid) for the removal of cobalt using polymer assisted ultrafiltration. High rejection rates were obtained between pH 3 and 6 with sulfonated poly(vinyl alcohol) (PVA 10,000 and 50,000 Da) whereas poly(acrylic acid) (PAA) of similar molecular weights performed rather poorly in this pH range. Sulfonation improved significantly sorption capability of PVA. Sulfonated PVA 10,000 was the best complexing agent with rejection rate above 95% between pH 3 and 6. For unmodified PVA the rejection rate was only 30-45% at pH 6 and there was no rejection at pH 3 at all. PAA rejection rate was above 90% at pH 6 and only about 10% at pH 3. Large scale experiment in cross-flow, continuous apparatus conducted by using PVA-SO{sub 3}H 10,000 Da to remove {sup 60}Co radioisotope from water solutions showed excellent results demonstrating the potential of this polymer to purify acidic radioactive wastes containing cobalt radioisotopes.

  5. Cheese whey protein recovery by ultrafiltration through transglutaminase (TG) catalysis whey protein cross-linking.

    Science.gov (United States)

    Wen-Qiong, Wang; Lan-Wei, Zhang; Xue, Han; Yi, Lu

    2017-01-15

    In whey ultrafiltration (UF) production, two main problems are whey protein recovery and membrane fouling. In this study, membrane coupling protein transglutaminase (TG) catalysis protein cross-linking was investigated under different conditions to find out the best treatment. We found that the optimal conditions for protein recovery involved catalyzing whey protein cross-linking with TG (40U/g whey proteins) at 40°C for 60min at pH 5.0. Under these conditions, the recovery rate was increased 15-20%, lactose rejection rate was decreased by 10%, and relative permeate flux was increase 30-40% compared to the sample without enzyme treatment (control). It was noticeable that the total resistance and cake resistance were decreased after enzyme catalysis. This was mainly due to the increased particle size and decreased zeta potential. Therefore, membrane coupling enzyme catalysis protein cross-linking is a potential means for further use. Copyright © 2016. Published by Elsevier Ltd.

  6. Physical–chemical properties, separation performance, and fouling resistance of mixed-matrix ultrafiltration membranes

    KAUST Repository

    Hoek, Eric M.V.

    2011-12-01

    Herein we report on the formation and characterization of mixed-matrix ultrafiltration (UF) membranes hand-cast by nonsolvent induced phase inversion. We evaluated nanometer-to-micrometer sized inorganic fillers (silver, copper, silica, zeolite, and silver-zeolite) materials with polysulfone (PSf) as the polymeric dispersing matrix. In general, mixed-matrix membranes were rougher, more hydrophilic, and more mechanically robust. Only sub-micron zeolite-PSf mixed-matrix membranes exhibited simultaneous improvements in water permeability and solute selectivity; all other mixed-matrix membranes were more permeable, but less selective due to defects associated with poor polymer-filler binding. Protein and bacterial fouling resistance of mixed-matrix membranes containing silver, zeolite, and silver-zeolite nanoparticles were compared to a low-fouling, poly(acrylonitrile) (PAN) UF membrane. Zeolite and silver containing membranes exhibited better protein fouling resistance (due to higher hydrophilicity), whereas silver and silver-zeolite based membranes produce better bacterial fouling resistance due to antimicrobial properties. Overall, zeolite-PSf and silver exchanged zeolite-PSf membranes offered the best combination of improved permeability, selectivity, and fouling resistance - superior to the commercial PAN membrane. © 2011 Elsevier B.V.

  7. Selective separation and concentration of antihypertensive peptides from rapeseed protein hydrolysate by electrodialysis with ultrafiltration membranes.

    Science.gov (United States)

    He, Rong; Girgih, Abraham T; Rozoy, Elodie; Bazinet, Laurent; Ju, Xing-Rong; Aluko, Rotimi E

    2016-04-15

    Rapeseed protein isolate was subjected to alcalase digestion to obtain a protein hydrolysate that was separated into peptide fractions using electrodialysis with ultrafiltration membrane (EDUF) technology. The EDUF process (6h duration) led to isolation of three peptide fractions: anionic (recovered in KCl-1 compartment), cationic (recovered in KCl-2 compartment), and those that remained in the feed compartment, which was labeled final rapeseed protein hydrolysate (FRPH). As expected the KCl-1 peptides were enriched in negatively-charged (43.57%) while KCl-2 contained high contents of positively-charged (28.35%) amino acids. All the samples inhibited angiotensin converting enzyme (ACE) and renin activities in dose-dependent manner with original rapeseed protein hydrolysate having the least ACE-inhibitory IC50 value of 0.0932±0.0037 mg/mL while FRPH and KCl-2 had least renin-inhibitory IC50 values of 0.47±0.05 and 0.55±0.06 mg/mL, respectively. Six hours after oral administration (100 mg/kg body weight) to spontaneously hypertensive rats, the FRPH produced the maximum systolic blood pressure reduction of -51 mmHg. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Selective removal of dissolved toxic metals from groundwater by ultrafiltration in combination with chemical treatment

    International Nuclear Information System (INIS)

    Buckley, L.P.; Le, V.T.; McConeghy, G.J.; Martin, J.F.

    1989-09-01

    An alternative in-place process for the removal of toxic heavy metals based on aqueous solution chemistry and treatment is being evaluated under the auspices of the Emerging Technologies Program funded through the USEPA's Superfund Innovative Technology Evaluation Program. The technique involves the contacting of aqueous solutions containing the heavy metal contaminants with low concentrations of polyelectrolytes, and then removing the polyelectrolytes from solution with ultrafiltration membranes. The first phase of the program is considered complete. Success has been achieved for the separation of soluble, heavy metal ions: cadmium, lead, and mercury even in the presence of an organic compound, toluene. Removal was successful at alkaline conditions, using any combination of membrane material or polyelectrolyte. Arsenic was removed, but not effectively, using the current polyelectrolytes, simply because arsenic is present as an anionic species rather than as a cationic species. Optimization of the process variables is nearing completion and pilot and field testing will take place in the second year of the program to verify the process under realistic conditions and to establish process economics

  9. Removal of emerging contaminants by simultaneous application of membrane ultrafiltration, activated carbon adsorption, and ultrasound irradiation

    International Nuclear Information System (INIS)

    Secondes, Mona Freda N.; Naddeo, Vincenzo; Belgiorno, Vincenzo; Ballesteros, Florencio

    2014-01-01

    Highlights: • Above 99% of the emerging contaminants were removed in the USAMe process. • Influence of PAC dose and US frequency on removal is studied. • Improved performance is due to PAC adsorption enhancement and sonolytic degradation. • US irradiation improved efficiency and delayed declines in the removal of contaminants. • Performance of the hybrid process is better under lower frequency ultrasound irradiation. -- Abstract: Advanced wastewater treatment is necessary to effectively remove emerging contaminants (ECs) with chronic toxicity, endocrine disrupting effects, and the capability to induce the proliferation of highly resistant microbial strains in the environment from before wastewater disposal or reuse. This paper investigates the efficiency of a novel hybrid process that applies membrane ultrafiltration, activated carbon adsorption, and ultrasound irradiation simultaneously to remove ECs. Diclofenac, carbamazepine, and amoxicillin are chosen for this investigation because of their assessed significant environmental risks. Removal mechanisms and enhancement effects are analysed in single and combined processes. The influence of adsorbent dose and ultrasonic frequency to EC removal are also investigated. Results suggest that adsorption is probably the main removal mechanism and is affected by the nature of ECs and the presence of other components in the mixture. Almost complete removals are achieved in the hybrid process for all ECs

  10. Effects of Wheat Gluten Hydrolysate and Its Ultrafiltration Fractions on Dough Properties and Bread Quality

    Directory of Open Access Journals (Sweden)

    Mouming Zhao

    2007-01-01

    Full Text Available Two fractions (50-K and permeate from a proteolytic hydrolysate (degree of hydrolysis, DH=3.8 % of wheat gluten were separated using ultrafiltration (UF membrane with molecular mass cut-off of 50 kDa. The effects of the wheat gluten hydrolysate (WGH and its UF fractions on the mixing behaviour and viscoelastic properties of wheat dough were presented. The WGH and its UF fractions modified the mixing properties of dough. The addition of these fractions improved the viscoelastic characteristics of wheat dough. A significant (p<0.05 effect of 50-K fraction on these characteristics of wheat dough was observed. After adding these fractions, the bread was considered acceptable by the sensory panel. Also, 50-K fraction resulted in significant (p<0.05 increase in the crumb firmness, while the bread made with wheat flour with WGH and permeate (P fraction showed softer crumbs compared to that of wheat flour. Moreover, these fractions had anti-staling properties for bread during storage. Hence, the wheat gluten hydrolysate and its UF fractions are the products with promising potential in the baking products.

  11. [Determination of plasma protein binding rate of arctiin and arctigenin with ultrafiltration].

    Science.gov (United States)

    Han, Xue-Ying; Wang, Wei; Tan, Ri-Qiu; Dou, De-Qiang

    2013-02-01

    To determine the plasma protein binding rate of arctiin and arctigenin. The ultrafiltration combined with HPLC was employed to determine the plasma protein binding rate of arctiin and arctigenin as well as rat plasma and healthy human plasma proteins. The plasma protein binding rate of arctiin with rat plasma at the concentrations of 64. 29, 32.14, 16.07 mg x L(-1) were (71.2 +/- 2.0)%, (73.4 +/- 0.61)%, (78.2 +/- 1.9)%, respectively; while the plasma protein binding rate of arctiin with healthy human plasma at the above concentrations were (64.8 +/- 3.1)%, (64.5 +/- 2.5)%, (77.5 +/- 1.7)%, respectively. The plasma protein binding rate of arctigenin with rat plasma at the concentrations of 77.42, 38.71, 19.36 mg x L(-1) were (96.7 +/- 0.41)%, (96.8 +/- 1.6)%, (97.3 +/- 0.46)%, respectively; while the plasma protein binding rate of arctigenin with normal human plasma at the above concentrations were (94.7 +/- 3.1)%, (96.8 +/- 1.6)%, (97.9 +/- 1.3)%, respectively. The binding rate of arctiin with rat plasma protein was moderate, which is slightly higher than the binding rate of arctiin with healthy human plasma protein. The plasma protein binding rates of arctigenin with both rat plasma and healthy human plasma are very high.

  12. Antioxidant activities of bambara groundnut (Vigna subterranea) protein hydrolysates and their membrane ultrafiltration fractions.

    Science.gov (United States)

    Arise, Abimbola K; Alashi, Adeola M; Nwachukwu, Ifeanyi D; Ijabadeniyi, Oluwatosin A; Aluko, Rotimi E; Amonsou, Eric O

    2016-05-18

    In this study, the bambara protein isolate (BPI) was digested with three proteases (alcalase, trypsin and pepsin), to produce bambara protein hydrolysates (BPHs). These hydrolysates were passed through ultrafiltration membranes to obtain peptide fractions of different sizes (fractions were investigated for antioxidant activities. The membrane fractions showed that peptides with sizes 3 kDa. This is in agreement with the result obtained for the ferric reducing power, metal chelating and hydroxyl radical scavenging activities where higher molecular weight peptides exhibited better activity (p fractions. However, for all the hydrolysates, the low molecular weight peptides were more effective diphenyl-1-picrylhydrazyl (DPPH) radical scavengers but not superoxide radicals when compared to the bigger peptides. In comparison with glutathione (GSH), BPHs and their membrane fractions had better (p fractions that did not show any metal chelating activity. However, the 5-10 kDa pepsin hydrolysate peptide fractions had greater (88%) hydroxyl scavenging activity than GSH, alcalase and trypsin hydrolysates (82%). These findings show the potential use of BPHs and their peptide fraction as antioxidants in reducing food spoilage or management of oxidative stress-related metabolic disorders.

  13. Enzymatic treatment for controlling irreversible membrane fouling in cross-flow humic acid-fed ultrafiltration

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Chien-Hwa [Department of Civil and Environment Engineering, Nanya Institute of Technology, Taoyuan, Taiwan (China); Fang, Lung-Chen; Lateef, Shaik Khaja [Graduate Institute of Environmental Engineering, National Taiwan University, Taipei, Taiwan (China); Wu, Chung-Hsin, E-mail: chunghsinwu@yahoo.com.tw [Department of Chemical and Materials Engineering, National Kaohsiung University of Applied Sciences, 415 Chien Kung Road, Kaohsiung 807, Taiwan (China); Lin, Cheng-Fang [Graduate Institute of Environmental Engineering, National Taiwan University, Taipei, Taiwan (China)

    2010-05-15

    Exploring reasonable ways to remove foulant is of great importance in order to allow sustainable operation of ultrafiltration (UF) membranes in water/wastewater treatment technology. Compounds of organic and inorganic origin largely contribute to irreversible fouling. This study attempted to remove problem of UF membrane fouling by using four different enzymes including {alpha}-amylase, lipase, cellulase and protease. This investigation showed that none of the above mentioned enzymes was found to be effective for the removal of foulant when used alone. However, when these enzymes were used in combination with NaOH and citric acid, about 90% cleaning was achieved. The addition of non-ionic surfactant to the enzymatic solution appears to increase the efficiency of flux recovery by reducing the adhesion of foulant species to the membrane surface through the decrease of contact angle. Field emission gun scanning electron microscopy, Fourier transform infrared spectroscopy and atomic force microscopy (AFM) techniques were employed to qualitatively illustrate the foulant characteristics. The surface roughness through AFM was used to explain the potential mechanism for the enzymatic cleaning.

  14. Performance of Hollow Fiber Ultrafiltration Membranes in the Clarification of Blood Orange Juice

    Directory of Open Access Journals (Sweden)

    Carmela Conidi

    2015-12-01

    Full Text Available The clarification of blood orange juice by ultrafiltration (UF was investigated by using three hollow fiber membrane modules characterized by different membrane materials (polysulfone (PS and polyacrylonitrile (PAN and molecular weight cut-off (MWCO (50 and 100 kDa. The performance of selected membranes was investigated in terms of productivity and selectivity towards total anthocyanin content (TAC, total phenolic content (TPC, and total antioxidant activity (TAA. All selected membranes allowed a good preservation of antioxidant compounds; however, the most suitable membrane for the clarification of the juice was found to be the PS 100 kDa membrane. In optimized operating conditions this membrane exhibited steady-state fluxes of 7.12 L/m2h, higher than those measured for other investigated membranes. Rejections towards TPC and TAA were of the order of 17.5% and 15%, respectively. These values were lower than those determined for PS 50 kDa and PAN 50 kDa membranes. In addition, the PS 100 kDa membrane exhibited a lower rejection (7.3% towards TAC when compared to the PS 50 kDa membrane (9.2%.

  15. Peritoneal transport in CAPD patients with permanent loss of ultrafiltration capacity

    International Nuclear Information System (INIS)

    Heimbuerger, O.W.; Waniewski, J.; Werynski, A.; Tranaeus, A.; Lindholm, B.

    1990-01-01

    During a 10 year period, 14 out of 227 patients (6.2%) undergoing continuous ambulatory peritoneal dialysis (CAPD) developed permanent loss of ultrafiltration capacity (UFC). The risk of UFC loss increased from 2.6% after one year to 30.9% after six years of treatment. A six hour, single dwell study with glucose 3.86% dialysis fluid was carried out in nine of the UFC loss patients and in 18 CAPD patients with normal UFC. Intraperitoneal dialysate volumes were calculated using 131I-tagged albumin (RISA) as volume marker with a correction applied for its elimination from the peritoneal cavity. The RISA elimination coefficient (KE), which can serve as an estimation of the upper limit of the lymphatic flow, was also calculated. Diffusive mass transport coefficients (KBD) for investigated solutes (glucose, creatinine, urea, potassium, total protein, albumin and beta 2-microglobulin) were calculated during a period of dialysate isovolemia. Two patterns of UFC loss were observed: (a) seven patients had high KBD values for small solutes resulting in rapid uptake of glucose, whereas KBD values for proteins were normal; (b) two patients had normal KBD values but a threefold increase both in the fluid reabsorption rate and KE. We conclude that loss of the osmotic driving force (due to increased diffusive mass transport for small solutes) and increased fluid reabsorption (possibly due to increased lymphatic reabsorption) are the two major causes of permanent loss of UFC in CAPD patients

  16. Effect of different concentrations of nisin on starter culture of model Cheeses manufactured from ultrafiltrated milk

    Directory of Open Access Journals (Sweden)

    Kh Mohammadi

    2013-05-01

    Full Text Available Nisin is a natural preservative produced by strains of Lactococcuslactis subsp. Lactis, has been approved for use in food by the Joint Food and Agricultural Organization/World Health Organization (FAO/WHO Committee on Food Additives and has been awarded generally recognized as safe (GRAS. It remains the only bacteriocin allowed in food as an addedpreservative. Nisin has a broad spectrum of antimicrobial activity againstgram-positive bacteria, thus one of the problems associated with nisin application is inhibition of starter culture and prevention of ripening, which is required for development of cheese characteristics during ripening. In the current study, the effects of different concentrations of nisin and temperature on growth and activity of lactic acid bacteria in model cheeses manufactured from ultrafiltrated milk was evaluated. Cheese samples were supplemented with nisin at concentrations of 0, 2, 4 and 6 µg/g and stored at 8 and 25 °C up to 60 days. Microbiological and physico-chemical properties of the cheese samples were analyzedat 0, 1, 8, 15, 30, 45 and 60 days. Results showed that addition of nisin at concentrations of 4 and 6 µg/g affects (p

  17. Polyethersulfone-based ultrafiltration hollow fibre membrane for drinking water treatment systems

    Science.gov (United States)

    Chew, Chun Ming; Ng, K. M. David; Ooi, H. H. Richard

    2017-12-01

    Conventional media/sand filtration has been the mainstream water treatment process for most municipal water treatment plants in Malaysia. Filtrate qualities of conventional media/sand filtration are very much dependent on the coagulation-flocculation process prior to filtration and might be as high as 5 NTU. However, the demands for better quality of drinking water through public piped-water supply systems are growing. Polymeric ultrafiltration (UF) hollow fibre membrane made from modified polyethersulfone (PES) material is highly hydrophilic with high tensile strength and produces excellent quality filtrate of below 0.3 NTU in turbidity. This advanced membrane filtration material is also chemical resistance which allows a typical lifespan of 5 years. Comparisons between the conventional media/sand filtration and PES-based UF systems are carried out in this paper. UF has been considered as the emerging technology in municipal drinking water treatment plants due to its consistency in producing high quality filtrates even without the coagulation-flocculation process. The decreasing cost of PES-based membrane due to mass production and competitive pricing by manufacturers has made the UF technology affordable for industrial-scale water treatment plants.

  18. Enzymatic treatment for controlling irreversible membrane fouling in cross-flow humic acid-fed ultrafiltration

    International Nuclear Information System (INIS)

    Yu, Chien-Hwa; Fang, Lung-Chen; Lateef, Shaik Khaja; Wu, Chung-Hsin; Lin, Cheng-Fang

    2010-01-01

    Exploring reasonable ways to remove foulant is of great importance in order to allow sustainable operation of ultrafiltration (UF) membranes in water/wastewater treatment technology. Compounds of organic and inorganic origin largely contribute to irreversible fouling. This study attempted to remove problem of UF membrane fouling by using four different enzymes including α-amylase, lipase, cellulase and protease. This investigation showed that none of the above mentioned enzymes was found to be effective for the removal of foulant when used alone. However, when these enzymes were used in combination with NaOH and citric acid, about 90% cleaning was achieved. The addition of non-ionic surfactant to the enzymatic solution appears to increase the efficiency of flux recovery by reducing the adhesion of foulant species to the membrane surface through the decrease of contact angle. Field emission gun scanning electron microscopy, Fourier transform infrared spectroscopy and atomic force microscopy (AFM) techniques were employed to qualitatively illustrate the foulant characteristics. The surface roughness through AFM was used to explain the potential mechanism for the enzymatic cleaning.

  19. New aspects of the possible sites of ultrafiltration in annelids (oligochaeta).

    Science.gov (United States)

    Hansen, U

    1995-02-01

    Electron microscopic investigations of blood vessels were conducted to show sites of filtration such as podocytes or fenestrated endothelia. The endothelia of the blood vessels of Aelosoma hemprichi, Nais elinguis, Dero obtusa and Enchytraeus buchholzi consist of myoendothelial cells, chloragocytes and podocytes. The podocytes form large archs over a considerable area of the vessels. On the lumen side of the vessel there are several columnar processes which split into numerous small pedicels. The gaps between the adjacent pedicles are bridged by slit membranes. The podocytes are restricted to the front part of the ventral vessel. They are presumed to form a filtration surface. Furthermore, some parts of the ventral vessel are formed by a fenestrated endothelium, mainly in Enchytraeus buchholzi. In the vascular system of E. buchholzi two separate filtration sites were found. Additionally to the filtration site between ventral vessel and coelomic cavity a second filtration site was found in the front part of the body between blood sinus and coelomic cavity. In such areas the basement membrane is the only continuous layer between the blood vessel and the coelomic cavity. Its thickness is in the range of 40 nm. Possible filtration sites in the form of podocytes and irregular fenestrations could be localized at the border between the blood compartment and the coelomic compartment. It can be presumed that the primary urine may be formed by ultrafiltration of blood.

  20. Pre-treatment and membrane ultrafiltration using treated palm oil mill effluent (POME

    Directory of Open Access Journals (Sweden)

    Wong Pui Wah

    2002-11-01

    Full Text Available Treatment of palm oil mill effluent (POME has always been a topic of research in Malaysia. This effluent that is extremely rich in organic content needs to be properly treated to minimize environmental hazards before it is released into watercourses. The common practice for treating POME in Malaysia involves a combination of aerobic and anaerobic methods. The purpose of tertiary treatment is to allow the treated water to be reused in the mill operations for other purposes such as feed water. The proposed treatment will also ensure the industry to meet a more stringent discharge standard in terms of the BOD, COD and nitrogen values. In this study membrane ultrafiltration is used as the tertiary treatment method. Before the actual membrane operation was conducted, the samples were pre-treated using three separate method namely filtration, centrifugation and coagulation. It was found that the combination of filtrationultrafiltration treatment POME produced the best-treated sample quality in terms of pollutant contents elimination, namely % BOD, % COD and % nitrogen removal.