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Sample records for reservoir core material

  1. LMFBR core materials

    International Nuclear Information System (INIS)

    Roberts, J.T.A

    1981-01-01

    This paper discusses initial fuel and core designs that are conservative, emphasizing high reliability at the expense of breeding ration and doubling time. The progression in design improvements to better doubling time, plutonium inventory requirements, and power density are shown. The recent progress in advanced oxide fuel, cladding, and duct development is reported. Breeding ratios and compound system doubling times are computed for both the conventional homogeneous and alternative heterogeneous core configurations. Results are summarized and it is shown that both carbide and metal cores can achieve breeding ratios in the range of 1.5 to 1.6 versus 1.45 for oxide; the carbide and metal cores can achieve 10 year doubling times, which translate into millions of dollars savings in fuel cycle costs. Carbide fuel development is being continued at a modest level to provide backup to the mixed oxide design

  2. Polar non-hydrocarbon contaminants in reservoir core extracts

    Directory of Open Access Journals (Sweden)

    Bennett B

    2000-08-01

    Full Text Available A geochemical investigation of oils in sandstone core plugs and drill stem test oils was carried out on samples from a North Sea reservoir. A sample of diesel used as a constituent of the drilling fluids was also analysed. The aliphatic and aromatic hydrocarbons and polar non-hydrocarbons were isolated using solid phase extraction methods. GC analysis of the hydrocarbon fraction of the core extract indicated that contamination may be diesel derived. From analysis of diesel some compound classes are less likely to be affected by contamination from diesel itself including: steranes, hopanes, aromatic steroid hydrocarbons, benzocarbazoles and C0–C3-alkylphenols. Large quantities of sterols (ca. 30 mg g-1 total soluble extract were identified in the polar non-hydrocarbon fractions of the core extract petroleum, presumably resulting from contamination. The origin of sterols is likely to be due to an additive introduced into the drilling fluid. Sterols are surface active compounds and in significant quantities may affect engineering core property measurements including wettability determinations. In addition, bulk petroleum composition screening methods, such as Iatroscan, used for determining saturated and aromatic hydrocarbons, resins and asphaltenes (SARA content of core extract petroleum may also be affected.

  3. Armor systems including coated core materials

    Science.gov (United States)

    Chu, Henry S [Idaho Falls, ID; Lillo, Thomas M [Idaho Falls, ID; McHugh, Kevin M [Idaho Falls, ID

    2012-07-31

    An armor system and method involves providing a core material and a stream of atomized coating material that comprises a liquid fraction and a solid fraction. An initial layer is deposited on the core material by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is less than the liquid fraction of the stream of atomized coating material on a weight basis. An outer layer is then deposited on the initial layer by positioning the core material in the stream of atomized coating material wherein the solid fraction of the stream of atomized coating material is greater than the liquid fraction of the stream of atomized coating material on a weight basis.

  4. Micro and macro constituents of sediment cores from Itupararanga reservoir Sorocaba, SP, by INAA

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Sharlleny A.; Ferreira, Francisco J., E-mail: shasilva@sp.gov.br [Companhia Ambiental do Estado de Sao Paulo (ELAI/CETESB), SP (Brazil). Setor de Quimica Inorganica; Bevilacqua, Jose Eduardo [Companhia Ambiental do Estado de Sao Paulo (CETESB), Osasco, SP (Brazil). Diretoria de Avaliacao de Impacto Ambiental; Favaro, Deborah I.T., E-mail: defavaro@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (LAN-CRPq/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Lab. de Analise por Ativacao Neutronica

    2013-07-01

    The Itupararanga reservoir was constructed by LIGHT for generating electrical energy, starting its operations in 1912. It is formed by the Sorocaba river dam. The reservoir finds itself in an area of strong environmental pressures. The waters of the Itupararanga reservoir are currently also used to supply approximately 63% of the basin of Sorocaba, in addition to power generation and recreation areas of nearby cities. Since 2003 it keeps receiving alerts from CETESB (Environmental Company of Sao Paulo State) that continues today. In this study four geo-referenced sampling points were used and bottom sediment samples were collected, were collected using a 60 cm core sampler, sliced at every 10 cm. The sediment samples were dried at 40 deg C, ground in an agate mortar, sieved (200 mesh) and again homogenized. Instrumental neutron activation analysis was applied to the sediment samples in order to determine some major elements (Fe, K and Na) and trace (As, Ba, Br, Co, Cr, Cs, Hf, Rb, Sb, Sc, Ta, Tb, Th, U and Zn) and rare earth (Ce, Eu, La, Lu, Nd, Sm, Tb and Yb) metals. The validation of the analytical methodology was performed by the analysis of certified reference materials. The results obtained were compared to NASC (North American Shale Composite) and UCC (Upper Continental Crust) reference values. The enrichment factors (EF) was assessed for sediment contamination index. Statistical tools of Factorial and Cluster analyses were applied to the data. (author)

  5. Analysis of structural heterogeneities on drilled cores: a reservoir modeling oriented methodology; Analyse des heterogeneites structurales sur carottes: une methodologie axee vers la modelisation des reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Cortes, P.; Petit, J.P. [Montpellier-2 Univ., Lab. de Geophysique, Tectonique et Sedimentologie, UMR CNRS 5573, 34 (France); Guy, L. [ELF Aquitaine Production, 64 - Pau (France); Thiry-Bastien, Ph. [Lyon-1 Univ., 69 (France)

    1999-07-01

    The characterization of structural heterogeneities of reservoirs is of prime importance for hydrocarbons recovery. A methodology is presented which allows to compare the dynamic behaviour of fractured reservoirs and the observation of microstructures on drilled cores or surface reservoir analogues. (J.S.)

  6. Dredged Material Management Plan and Environmental Impact Statement. McNary Reservoir and Lower Snake River Reservoirs. Appendix C: Economic Analysis

    National Research Council Canada - National Science Library

    2002-01-01

    ...; for managment of dredged material from these reservoirs; and for maintenance of flow conveyance capacity at the most upstream extent of the Lower Granite reservoir for the remaining economic life of the dam and reservoir project (to year 2074...

  7. Reactor core materials research and integrated material database establishment

    International Nuclear Information System (INIS)

    Ryu, Woo Seog; Jang, J. S.; Kim, D. W.

    2002-03-01

    Mainly two research areas were covered in this project. One is to establish the integrated database of nuclear materials, and the other is to study the behavior of reactor core materials, which are usually under the most severe condition in the operating plants. During the stage I of the project (for three years since 1999) in- and out of reactor properties of stainless steel, the major structural material for the core structures of PWR (Pressurized Water Reactor), were evaluated and specification of nuclear grade material was established. And the damaged core components from domestic power plants, e.g. orifice of CVCS, support pin of CRGT, etc. were investigated and the causes were revealed. To acquire more resistant materials to the nuclear environments, development of the alternative alloys was also conducted. For the integrated DB establishment, a task force team was set up including director of nuclear materials technology team, and projector leaders and relevant members from each project. The DB is now opened in public through the Internet

  8. Source, composition, and environmental implication of neutral carbohydrates in sediment cores of subtropical reservoirs, South China

    Science.gov (United States)

    Duan, Dandan; Zhang, Dainan; Yang, Yu; Wang, Jingfu; Chen, Jing'an; Ran, Yong

    2017-09-01

    Neutral monosaccharides, algal organic matter (AOM), and carbon stable isotope ratios in three sediment cores of various trophic reservoirs in South China were determined by high-performance anion-exchange chromatography, Rock-Eval pyrolysis, and Finnigan Delta Plus XL mass spectrometry, respectively. The carbon isotopic compositions were corrected for the Suess effect. The concentrations of total neutral carbohydrates (TCHO) range from 0.51 to 6.4 mg g-1 at mesotrophic reservoirs, and from 0.83 to 2.56 mg g-1 at an oligotrophic reservoir. Monosaccharide compositions and diagnostic parameters indicate a predominant contribution of phytoplankton in each of the three cores, which is consistent with the results inferred from the corrected carbon isotopic data and C/N ratios. The sedimentary neutral carbohydrates are likely to be structural polysaccharides and/or preserved in sediment minerals, which are resistant to degradation in the sediments. Moreover, the monosaccharide contents are highly related to the carbon isotopic data, algal productivity estimated from the hydrogen index, and increasing mean air temperature during the past 60 years. The nutrient input, however, is not a key factor affecting the primary productivity in the three reservoirs. The above evidence demonstrates that some of the resistant monosaccharides have been significantly elevated by climate change, even in low-latitude regions.

  9. Structure and Filling Characteristics of Paleokarst Reservoirs in the Northern Tarim Basin, Revealed by Outcrop, Core and Borehole Images

    Science.gov (United States)

    Tian, Fei; Lu, Xinbian; Zheng, Songqing; Zhang, Hongfang; Rong, Yuanshuai; Yang, Debin; Liu, Naigui

    2017-06-01

    The Ordovician paleokarst reservoirs in the Tahe oilfield, with burial depths of over 5300 m, experienced multiple phases of geologic processes and exhibit strong heterogeneity. Core testing can be used to analyse the characteristics of typical points at the centimetre scale, and seismic datasets can reveal the macroscopic outlines of reservoirs at the >10-m scale. However, neither method can identify caves, cave fills and fractures at the meter scale. Guided by outcrop investigations and calibrations based on core sample observations, this paper describes the interpretation of high longitudinal resolution borehole images, the identification of the characteristics of caves, cave fills (sedimentary, breccia and chemical fills) and fractures in single wells, and the identification of structures and fill characteristics at the meter scale in the strongly heterogeneous paleokarst reservoirs. The paleogeomorphology, a major controlling factor in the distribution of paleokarst reservoirs, was also analysed. The results show that one well can penetrate multiple cave layers of various sizes and that the caves are filled with multiple types of fill. The paleogeomorphology can be divided into highlands, slopes and depressions, which controlled the structure and fill characteristics of the paleokarst reservoirs. The results of this study can provide fundamental meter-scale datasets for interpreting detailed geologic features of deeply buried paleocaves, can be used to connect core- and seismic-scale interpretations, and can provide support for the recognition and development of these strongly heterogeneous reservoirs.

  10. Structure and Filling Characteristics of Paleokarst Reservoirs in the Northern Tarim Basin, Revealed by Outcrop, Core and Borehole Images

    Directory of Open Access Journals (Sweden)

    Tian Fei

    2017-06-01

    Full Text Available The Ordovician paleokarst reservoirs in the Tahe oilfield, with burial depths of over 5300 m, experienced multiple phases of geologic processes and exhibit strong heterogeneity. Core testing can be used to analyse the characteristics of typical points at the centimetre scale, and seismic datasets can reveal the macroscopic outlines of reservoirs at the >10-m scale. However, neither method can identify caves, cave fills and fractures at the meter scale. Guided by outcrop investigations and calibrations based on core sample observations, this paper describes the interpretation of high longitudinal resolution borehole images, the identification of the characteristics of caves, cave fills (sedimentary, breccia and chemical fills and fractures in single wells, and the identification of structures and fill characteristics at the meter scale in the strongly heterogeneous paleokarst reservoirs. The paleogeomorphology, a major controlling factor in the distribution of paleokarst reservoirs, was also analysed. The results show that one well can penetrate multiple cave layers of various sizes and that the caves are filled with multiple types of fill. The paleogeomorphology can be divided into highlands, slopes and depressions, which controlled the structure and fill characteristics of the paleokarst reservoirs. The results of this study can provide fundamental meter-scale datasets for interpreting detailed geologic features of deeply buried paleocaves, can be used to connect core- and seismic-scale interpretations, and can provide support for the recognition and development of these strongly heterogeneous reservoirs.

  11. Scaling of Core Material in Rubble Mound Breakwater Model Tests

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Liu, Z.; Troch, P.

    1999-01-01

    The permeability of the core material influences armour stability, wave run-up and wave overtopping. The main problem related to the scaling of core materials in models is that the hydraulic gradient and the pore velocity are varying in space and time. This makes it impossible to arrive at a fully...

  12. Permeability model of tight reservoir sandstones combining core-plug and miniperm analysis of drillcore; longyearbyen co2lab, Svalbard

    NARCIS (Netherlands)

    Magnabosco, Cara; Braathen, Alvar; Ogata, Kei

    2014-01-01

    Permeability measurements in Mesozoic, low-permeability sandstone units within the strata cored in seven drillholes near Longyearbyen, Svalbard, have been analysed to assess the presence of aquifers and their potentials as reservoirs for the storage of carbon dioxide. These targeted sandstones are

  13. Study of different factors affecting the electrical properties of natural gas reservoir rocks based on digital cores

    International Nuclear Information System (INIS)

    Jiang, Liming; Sun, Jianmeng; Wang, Haitao; Liu, Xuefeng

    2011-01-01

    The effects of the wettability and solubility of natural gas in formation water on the electrical properties of natural gas reservoir rocks are studied using the finite element method based on digital cores. The results show that the resistivity index of gas-wet reservoir rocks is significantly higher than that of water-wet reservoir rocks in the entire range of water saturation. The difference between them increases with decreasing water saturation. The resistivity index of natural gas reservoir rocks decreases with increasing additional conduction of water film. The solubility of natural gas in formation water has a dramatic effect on the electrical properties of reservoir rocks. The resistivity index of reservoir rocks increases as the solubility of natural gas increases. The effect of the solubility of natural gas on the resistivity index is very obvious under conditions of low water saturation, and it becomes weaker with increasing water saturation. Therefore, the reservoir wettability and the solubility of natural gas in formation water should be considered in defining the saturation exponent

  14. Research on removing reservoir core water sensitivity using the method of ultrasound-chemical agent for enhanced oil recovery.

    Science.gov (United States)

    Wang, Zhenjun; Huang, Jiehao

    2018-04-01

    The phenomenon of water sensitivity often occurs in the oil reservoir core during the process of crude oil production, which seriously affects the efficiency of oil extraction. In recent years, near-well ultrasonic processing technology attaches more attention due to its safety and energy efficient. In this paper, the comparison of removing core water sensitivity by ultrasonic wave, chemical injection and ultrasound-chemical combination technique are investigated through experiments. Results show that: lower ultrasonic frequency and higher power can improve the efficiency of core water sensitivity removal; the effects of removing core water sensitivity under ultrasonic treatment get better with increase of core initial permeability; the effect of removing core water sensitivity using ultrasonic treatment won't get better over time. Ultrasonic treatment time should be controlled in a reasonable range; the effect of removing core water sensitivity using chemical agent alone is slightly better than that using ultrasonic treatment, however, chemical injection could be replaced by ultrasonic treatment for removing core water sensitivity from the viewpoint of oil reservoir protection and the sustainable development of oil field; ultrasound-chemical combination technique has the best effect for water sensitivity removal than using ultrasonic treatment or chemical injection alone. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Radionuclide sorption on granitic drill core material

    International Nuclear Information System (INIS)

    Eriksen, T.E.; Locklund, B.

    1987-11-01

    Distribution ratios were determined for Sr-85, Cs-134 and Eu-152 on crushed granite and fissure coating/filling material from Stripa mines. Measurements were also carried out on intact fissure surfaces. The experimental data for Sr-85, Cs-134 on crushed material can be accomodated by a sorption model based on the assumption that the crushed material consists of porous spheres with outer and inner surfaces available for sorption. In the case of Eu-152 only sorption on the outer surfaces of the crushed material was observed. The absence of sorption on inner surfaces is most probably due to high depletion of the more strongly sorbed Eu-152 in the water phase and very low diffusivity of Eu-152 in the sorbed state. (orig./HP)

  16. Innovative core material produced by infusion process using hemp fibres

    Science.gov (United States)

    Boccarusso, L.; Carrino, L.; Durante, M.; Formisano, A.; Langella, A.; Minutolo, F. Memola Capece

    2016-10-01

    This paper investigates the mechanical properties in term of compression, tensile, flexural and shear strength of a new hemp core based on woven fabric. The hemp core is manufactured by means an innovative vacuum infusion process in which the input both of epoxy resin and of air was allowed. In addition, a comparison among this and others more known materials used as core in sandwich structures was carried out. The results showed that the core under investigation has higher mechanical properties, without shear and indentation failure during the tests on the respective sandwich structures.

  17. Water sorption and solubility of core build-up materials.

    Science.gov (United States)

    Zankuli, M A; Devlin, H; Silikas, N

    2014-12-01

    To investigate the variation in water sorption and solubility across a range of different core build-up materials. Five materials were tested, four of which are resin-based materials (Grandio Core, Core.X Flow, Bright Flow Core, Speedee) and one resin-modified glass ionomer (Fuji II LC). All specimens (n=10) were immersed in 10ml distilled water in individual glass containers and weighed at one week, 14 and 28 days. After a total immersion time of 28 days, 7 specimens were dried to a constant mass, in a desiccator for 28 days. Three samples of each material were not dried, but were left in distilled water for 1 year, to determine the long-term water sorption properties. Specimens were weighed at monthly intervals until 6 months and then at the 9th and 12th months. Each specimen was measured using a digital electronic caliper (Mitutoyo Corporation, Japan). After 28 days immersion, the change in water sorption and solubility of the materials ranged from 12.9 to 67.1μg/mm(3) (PGrandio Core had the lowest water sorption and solubility among the tested materials. According to the ISO 4049 standards, all the tested materials showed acceptable water sorption and solubility, apart from the water sorption behavior of Fuji II LC. Copyright © 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  18. Episodic entrainment of primordial material in plumes from isolated lower mantle reservoirs

    Science.gov (United States)

    Williams, C. D.; McNamara, A. K.; Garnero, E. J.; Van Soest, M. C.

    2012-12-01

    The noble gas systematics observed in ocean island basalts (OIBs) relative to mid-ocean ridge basalts (MORBs), suggests OIBs preferentially sample a primordial reservoir located somewhere within Earth's mantle. The lower mantle has been favored as a candidate reservoir, either in its entirety or discrete reservoirs located within it. Thermal plumes originating from the lower mantle could potentially sample these reservoirs, which may have remained isolated from the MORB source region over much of Earth's history. Recently, seismic observations of two, nearly anti-podal large, low-shear velocity provinces (LLSVPs) in the lowermost mantle have been hypothesized as being chemically distinct, and thus, may be long-lived reservoirs that have retained primordial noble gas signatures from earlier in Earth's history. Geodynamic models predict that thermal plumes are likely to be associated with LLSVPs and could potentially entrain a small amount of these chemically distinct reservoirs, which may ultimately reach the surface of the Earth in the form of OIBs. However, isotopic variability within OIBs challenges the notion of multiple plumes tapping the same reservoir. Here, we perform geodynamic calculations that investigate the time-dependent rate of material entrained into thermal plumes from these primordial reservoirs. In particular, we examine how the rate of entrainment varies within a single, long-lived thermal plume with a relatively steady buoyancy flux. Using phase relations for mantle peridotite, the amount of entrained material comprising the melt is estimated. We find that time-dependent dynamical processes at the interface between a deep, primordial reservoir and the base of a mantle plume strongly influences the entrainment rate, causing the amount of entrainment to vary episodically with time. Thus, melts rising to the surface (e.g., OIBs) are predicted to contain variable proportions of material entrained from these primordial reservoirs. This time

  19. Water-quality trends in the Rio Grande/Rio Bravo Basin using sediment cores from reservoirs

    Science.gov (United States)

    Van Metre, Peter C.; Mahler, B.J.; Callender, Edward C.

    1997-01-01

    Water-quality trends reflect the relation between water quality and human activities, chronicling changes in concentrations of environmental contaminants, introduction of new contaminants, and successful efforts in environmental pollution remediation. Historical data available for analyzing trends often have severe limitations, from questionable accuracy to unknown sampling and analytic methodologies. Where data are unavailable or have such limitations, water-quality trends sometimes can be reconstructed using sediment cores from lakes and reservoirs.

  20. A finite element thermal analysis of various dowel and core materials

    Directory of Open Access Journals (Sweden)

    Shanti Varghese

    2012-01-01

    Conclusion: Non-metallic dowel and core materials such as fibre reinforced composite dowels (FRC generate greater stress than metallic dowel and core materials. This emphasized the preferable use of the metallic dowel and core materials in the oral environment.

  1. Retention of selected core materials to zirconia posts.

    Science.gov (United States)

    Edelhoff, D; Sorensen, J A

    2002-01-01

    Due to their favorable optical and mechanical properties, endodontic posts made of partially stabilized zirconia ceramic (ZrO2-Y2O3) are a promising alternative to those made of metal. Zirconia posts can be combined with various tooth-colored core materials to increase the optical properties of a final esthetic restoration. For stability, a reliable bond between core material and the post should be generated. This in vitro study evaluated the retention of selected core materials to zirconia posts dependent on different surface treatments and bonding procedures. Two types of zirconia posts (CeraPost [CEP], Lemgo, Germany) and CosmoPost [COP], Ivoclar Vivadent, Amherst NY 14228, USA) were employed for the study. Ring-shaped cores were fabricated of either heat-pressed, zirconia-containing glass ceramic (IPS Empress Cosmo [EMC], Ivoclar Vivadent), highly-filled hybrid composite (Tetric Ceram [TEC], Ivoclar Vivadent) or an experimental, high-strength glass ceramic (OHSU-RWTH [EX], Ivoclar Vivadent). The core made of material EX was either directly heat pressed (EXP) or adhesively bonded (EXB) onto the post using a flowable composite. Prior to core application, the post surfaces were preconditioned by alumina abrasion (AA) or tribochemical silicoating and silanation (TCS). Specimens (10 per group) were stored in artificial saliva (pH 5.2) for 150 days. Storage time included 5,000 thermocycles (5/55 degrees C per 30 seconds). Defect analysis was conducted visually using a light microscope and a fiber optic transillumination prior to the testing procedure. The loads required to separate post and core were determined by a push-out test. Following testing, the surfaces of the posts and core materials were evaluated in a scanning electron microscope (SEM). There were no statistically significant differences between the separation loads of groups COP/AA/EMC, COP/TCS/TEC, CEP/AA/EMC and COP/AA/EXB. Group COP/AA/EXP showed significantly higher retention, but also the highest

  2. Radiation quality factor of spherical antennas with material cores

    DEFF Research Database (Denmark)

    Hansen, Troels Vejle; Kim, Oleksiy S.; Breinbjerg, Olav

    2011-01-01

    This paper gives a description of the radiation quality factor and resonances of spherical antennas with material cores. Conditions for cavity and radiating resonances are given, and a theoretical description of the radiation quality factor, as well as simple expressions describing the relative...... increase in quality factor due to the effect of the internally stored energy are given in special cases. For the air-core antenna of vanishing size, it is shown that the dipole modes are the modes providing the lowest quality factor of all modes. Finally an investigation of the effect of the core...

  3. Fatigue Characterization of Fire Resistant Syntactic Foam Core Material

    Science.gov (United States)

    Hossain, Mohammad Mynul

    Eco-Core is a fire resistant material for sandwich structural application; it was developed at NC A&T State University. The Eco-Core is made of very small amount of phenolic resin and large volume of flyash by a syntactic process. The process development, static mechanical and fracture, fire and toxicity safety and water absorption properties and the design of sandwich structural panels with Eco-Core material was established and published in the literature. One of the important properties that is needed for application in transportation vehicles is the fatigue performance under different stress states. Fatigue data are not available even for general syntactic foams. The objective of this research is to investigate the fatigue performance of Eco-Core under three types of stress states, namely, cyclic compression, shear and flexure, then document failure modes, and develop empherical equations for predicting fatigue life of Eco-Core under three stress states. Compression-Compression fatigue was performed directly on Eco-Core cylindrical specimen, whereas shear and flexure fatigue tests were performed using sandwich beam made of E glass-Vinyl Ester face sheet and Eco-Core material. Compression-compression fatigue test study was conducted at two values of stress ratios (R=10 and 5), for the maximum compression stress (sigmamin) range of 60% to 90% of compression strength (sigmac = 19.6 +/- 0.25 MPa) for R=10 and 95% to 80% of compression strength for R=5. The failure modes were characterized by the material compliance change: On-set (2% compliance change), propagation (5%) and ultimate failure (7%). The number of load cycles correspond to each of these three damages were characterized as on-set, propagation and total lives. A similar approach was used in shear and flexure fatigue tests with stress ratio of R=0.1. The fatigue stress-number of load cycles data followed the standard power law equation for all three stress states. The constant of the equation were

  4. Applications of simulation experiments in LMFBR core materials technology

    International Nuclear Information System (INIS)

    Appleby, W.K.

    1976-01-01

    The development of charged particle bombardment experiments to simulate neutron irradiation induced swelling in austenitic alloys is briefly described. The applications of these techniques in LMFBR core materials technology are discussed. It is shown that use of the techniques to study the behavior of cold-worked Type-316 was instrumental in demonstrating at an early date the need for advanced materials. The simulation techniques then were used to identify alloying elements which can markedly decrease swelling and thus a focused reactor irradiation program is now in place to allow the future use of a lower swelling alloy for LMFBR core components

  5. Spectrophotometric Evaluation of Polyetheretherketone (PEEK as a Core Material and a Comparison with Gold Standard Core Materials

    Directory of Open Access Journals (Sweden)

    Bogna Stawarczyk

    2016-06-01

    Full Text Available This study investigated the colorimetric properties of different veneering materials on core materials. Standardized specimens (10 mm × 10 mm × 1.5 mm reflecting four core (polyetheretherketone (PEEK, zirconia (ZrO2, cobalt–chromium–molybdenum alloy (CoCrMo, and titanium oxide (TiO2; thickness: 1.5 mm and veneering materials (VITA Mark II, IPS e.max CAD, LAVA Ultimate and VITA Enamic, all in shade A3; thickness: 0.5, 1.0, 1.5 and 2 mm, respectively were fabricated. Specimens were superimposed to assemblies, and the color was determined with a spectrophotometer (CieLab-System or a chair-side color measurement device (VITA EasyShade, respectively. Data were analyzed using three-, two-, and one-way ANOVA, a Chi2-test, and a Wilson approach (p < 0.05. The measurements with EasyShade showed A2 for VITA Mark II, A3.5 for VITA Enamic, B2 for LAVA Ultimate, and B3 for IPS e.max CAD. LabE-values showed significant differences between the tested veneering materials (p < 0.001. CieLab-System and VITA EasyShade parameters of the different assemblies showed a significant impact of core (p < 0.001, veneering material (p < 0.001, and thickness of the veneering material (p < 0.001. PEEK as core material showed comparable outcomes as compared to ZrO2 and CoCrMo, with respect to CieLab-System parameters for each veneering material. The relative frequency of the measured VITA EasyShade parameters regarding PEEK cores also showed comparable results as compared to the gold standard CoCrMo, regardless of the veneering material used.

  6. Nanostructured core-shell electrode materials for electrochemical capacitors

    Science.gov (United States)

    Jiang, Long-bo; Yuan, Xing-zhong; Liang, Jie; Zhang, Jin; Wang, Hou; Zeng, Guang-ming

    2016-11-01

    Core-shell nanostructure represents a unique system for applications in electrochemical energy storage devices. Owing to the unique characteristics featuring high power delivery and long-term cycling stability, electrochemical capacitors (ECs) have emerged as one of the most attractive electrochemical storage systems since they can complement or even replace batteries in the energy storage field, especially when high power delivery or uptake is needed. This review aims to summarize recent progress on core-shell nanostructures for advanced supercapacitor applications in view of their hierarchical architecture which not only create the desired hierarchical porous channels, but also possess higher electrical conductivity and better structural mechanical stability. The core-shell nanostructures include carbon/carbon, carbon/metal oxide, carbon/conducting polymer, metal oxide/metal oxide, metal oxide/conducting polymer, conducting polymer/conducting polymer, and even more complex ternary core-shell nanoparticles. The preparation strategies, electrochemical performances, and structural stabilities of core-shell materials for ECs are summarized. The relationship between core-shell nanostructure and electrochemical performance is discussed in detail. In addition, the challenges and new trends in core-shell nanomaterials development have also been proposed.

  7. Advances in core loss calculations for magnetic materials

    Science.gov (United States)

    Triner, J. E.

    1982-01-01

    A new analytical technique which predicts the basic magnetic properties under various operating conditions encountered in state-of-the-art dc-ac/dc converters is discussed. Using a new flux-controlled core excitation circuit, magnetic core characteristics were developed for constant values of ramp flux (square wave voltage excitation) and frequency. From this empirical data, a mathematical loss characteristics equation is developed to analytically predict the specific core loss of several magnetic materials under various waveform excitation conditions. In addition, these characteristics show the circuit designer for the first time the direct functional relatonships between induction level and specific core loss as a function of the two key dc-dc converter operating parameters of input voltage and duty cycle.

  8. Microleakage of core materials for complete cast gold crowns.

    Science.gov (United States)

    Tjan, A H; Chiu, J

    1989-06-01

    This study evaluated the microleakage patterns of complete cast-gold crowns cemented onto teeth rebuilt with pin-retained cores made from cast gold, amalgam, composite resin, and silver-reinforced glass ionomer by using three different cements (zinc phosphate, glass ionomer, and resin cement). Crowns cemented onto unrebuilt tooth preparations with zinc phosphate cement served as controls. The cemented specimens were thermocycled between 4 degrees and 50 degrees C in waterbaths. They were then embedded in epoxy resin and sectioned. The extent of marginal microleakage was evaluated with a stereomicroscope and scored. The findings indicated that the type of luting agent used appeared to affect microleakage more than the core material. No significant differences in the degree of microleakage were found under crowns cemented onto teeth rebuilt with the four core materials when cemented with the same luting cement.

  9. Spectrophotometric Evaluation of Polyetheretherketone (PEEK) as a Core Material and a Comparison with Gold Standard Core Materials

    Science.gov (United States)

    Stawarczyk, Bogna; Schmid, Philipp; Roos, Malgorzata; Eichberger, Marlis; Schmidlin, Patrick R.

    2016-01-01

    This study investigated the colorimetric properties of different veneering materials on core materials. Standardized specimens (10 mm × 10 mm × 1.5 mm) reflecting four core (polyetheretherketone (PEEK), zirconia (ZrO2), cobalt–chromium–molybdenum alloy (CoCrMo), and titanium oxide (TiO2); thickness: 1.5 mm) and veneering materials (VITA Mark II, IPS e.max CAD, LAVA Ultimate and VITA Enamic, all in shade A3; thickness: 0.5, 1.0, 1.5 and 2 mm, respectively) were fabricated. Specimens were superimposed to assemblies, and the color was determined with a spectrophotometer (CieLab-System) or a chair-side color measurement device (VITA EasyShade), respectively. Data were analyzed using three-, two-, and one-way ANOVA, a Chi2-test, and a Wilson approach (p veneering materials (p veneering material (p veneering material (p veneering material. The relative frequency of the measured VITA EasyShade parameters regarding PEEK cores also showed comparable results as compared to the gold standard CoCrMo, regardless of the veneering material used. PMID:28773612

  10. Reaction behaviour of reactor materials, including concrete during core meltdown

    International Nuclear Information System (INIS)

    Holleck, H.; Hofmann, P.; Skokan, A.

    1976-01-01

    The problems dealt with in the studies on the material behaviour of core meltdowns are sketched, and an outline is given on the experimental investigations now in progress. These studies aim at establishing a model which is as realistic as possible, and the paper tries to show that knowledge on the reaction behaviour is a basic prerequisite for this. (orig./TK) [de

  11. Fish colonization of artificial reefs in a large neotropical reservoir: material type and successional changes.

    Science.gov (United States)

    Santos, Luciano N; García-Berthou, Emili; Agostinho, Angelo A; Latini, João D

    2011-01-01

    Artificial reefs have barely been used in Neotropical reservoirs (about five studies in three reservoirs), despite their potential as a fishery management tool to create new habitats and also to understand fish ecology. We experimentally assessed how reef material (ceramic, concrete, and PVC) and time modulated fish colonization of artificial reefs deployed in Itaipu Reservoir, a large reservoir of the mainstem Paraná River, Brazil. Fish richness, abundance, and biomass were significantly greater in the reef treatments than at control sites. Among the experimental reefs, ceramic followed by the concrete treatments were the materials most effectively colonized, harboring the majority of the 13 fish species recorded. Although dependent on material type, many of the regularities of ecological successions were also observed in the artificial reefs, including decelerating increases in species richness, abundance, mean individual size, and species loss rates with time and decelerating decreases of species gain and turnover rates. Species composition also varied with material type and time, together with suites of life history traits: more equilibrium species (i.e., fishes of intermediate size that often exhibit parental care and produce fewer but larger offspring) of the Winemiller-Rose model of fish life histories prevailed in later successional stages. Overall, our study suggests that experimental reefs are a promising tool to understand ecological succession of fish assemblages, particularly in tropical ecosystems given their high species richness and low seasonality.

  12. In-core and out-of-core materials selection for the HPLWR

    International Nuclear Information System (INIS)

    Ehrlich, K.; Konys, J.; Leistikow, S.; Steiner, H.; Schirra, M.; Heikinheimo, L.; Arnoux, P.

    2004-01-01

    In this report a state-of-the-art study was performed to investigate the operational conditions for in-core and ex-vessel materials in a future High Performance Light Water Reactor (HPLWR) and to evaluate the potential of existing structural materials for application in fuel elements, core structures and out-of-core components. In the conventional parts of such a novel plant the approved materials of supercritical fossil power plants (SCFPP) can be used for the given temperature (. 600 C) and pressure (. 250 bar). These are either ferritic/martensitic or austenitic stainless steels. The design data for the in-core components are, however, very ambitious in comparison with conventional Light Water Reactors, especially regarding the coolant which is under high pressure (. 250 bar) and will have a transition from sub- to supercritical state in the core, since the water temperature increases from 290 to 510 C outlet. The expected temperature in the cladding of the fuel elements can reach up to 650 C and the neutron exposure can accumulate up to 1.13.10 2 3 n/cm 2 or 60 displacements per atom (dpa) for an envisaged target of 70 GWd/t U burnup. Taking these novel operational conditions into account an assessment of available material data was made. It is based on existing creep-rupture data, an extensive analysis of the corrosion in conventional steam power plants and the material behavior under irradiation. Compatibility between fuel and cladding materials is also considered. The potential of the different material groups available for in-core application, to be used as cladding materials of fuel elements, was further investigated by quantitative assumptions on the stress development in claddings and by a determination of the maximum achievable temperatures in dependence of cladding dimensions and the above mentioned operational conditions. More qualitative arguments on stress corrosion susceptibility are also included. It was stated that for a maximum temperature of

  13. Characterization of gas hydrate reservoirs by integration of core and log data in the Ulleung Basin, East Sea

    Science.gov (United States)

    Bahk, J.-J.; Kim, G.-Y.; Chun, J.-H.; Kim, J.-H.; Lee, J.Y.; Ryu, B.-J.; Lee, J.-H.; Son, B.-K.; Collett, Timothy S.

    2013-01-01

    Examinations of core and well-log data from the Second Ulleung Basin Gas Hydrate Drilling Expedition (UBGH2) drill sites suggest that Sites UBGH2-2_2 and UBGH2-6 have relatively good gas hydrate reservoir quality in terms of individual and total cumulative thicknesses of gas-hydrate-bearing sand (HYBS) beds. In both of the sites, core sediments are generally dominated by hemipelagic muds which are intercalated with turbidite sands. The turbidite sands are usually thin-to-medium bedded and mainly consist of well sorted coarse silt to fine sand. Anomalies in infrared core temperatures and porewater chlorinity data and pressure core measurements indicate that “gas hydrate occurrence zones” (GHOZ) are present about 68–155 mbsf at Site UBGH2-2_2 and 110–155 mbsf at Site UBGH2-6. In both the GHOZ, gas hydrates are preferentially associated with many of the turbidite sands as “pore-filling” type hydrates. The HYBS identified in the cores from Site UBGH2-6 are medium-to-thick bedded particularly in the lower part of the GHOZ and well coincident with significant high excursions in all of the resistivity, density, and velocity logs. Gas-hydrate saturations in the HYBS range from 12% to 79% with an average of 52% based on pore-water chlorinity. In contrast, the HYBS from Site UBGH2-2_2 are usually thin-bedded and show poor correlations with both of the resistivity and velocity logs owing to volume averaging effects of the logging tools on the thin HYBS beds. Gas-hydrate saturations in the HYBS range from 15% to 65% with an average of 37% based on pore-water chlorinity. In both of the sites, large fluctuations in biogenic opal contents have significant effects on the sediment physical properties, resulting in limited usage of gamma ray and density logs in discriminating sand reservoirs.

  14. Integration of Well & Core Data of Carbonate Reservoirs with Surface Seismic in Garraf Oil Field, Southern Iraq

    Science.gov (United States)

    Mhuder, J. J.; Muhlhl, A. A.; Basra Geologiests

    2013-05-01

    The Garraf Field is situated in Southern Iraq in Nasiriya area, is located in Mesopotamian basin. The carbonate facies are dominant in main reservoirs in Garraf field (Mishrif and Yammama Formations) which is Cretaceous in age. The structure of the reservoir in this field are low relief gentle anticlinal structure aligned in NW to SE direction, and No fault were observed and interpreted in 3D seismic section. 3D seismic survey by Iraqi Oil Exploration Company No 2 was successfully conducted on the Garraf field at 2008-2009 using recording system SERCEL 408UL and Vibrators Nomad 65. Bin size: 25*25, Fold: 36, SP Interval: 50m, Lines Interval: 300m, 3 wells were drilled Ga (1, 2, 3) and it used for seismic to well tie in Petrel. Data analysis was conducted for each reservoirs for Lithological and sedimentological studies were based on core and well data .The study showed That the Mishrif Formation deposited in a broad carbonate platform with shallowing upward regressive succession and The depositional environment is extending from outer marine to shallow middle-inner shelf settings with restricted lagoons as supported by the present of Miliolid fossils. The fragmented rudist biostromes accumulated in the middle shelf. No rudist reef is presence in the studied cores. While the Major sequences are micritic limestone of lagoonal and oolitic/peloidal grainstone sandy shoal separated by mudstone of Yamama formation. Sedimentation feature are seen on seismic attributes and it is help for understanding of sedimentation environment and suitable structure interpretation. There is good relationship between Acustic Impedance and porosity, Acustic Impedance reflects porosity or facies change of carbonate rather than fluid content. Data input used for 3D Modeling include 3D seismic and AI data, petrophysical analysis, core and thin section description. 3D structure modeling were created base on the geophysical data interpretation and Al analysis. Data analysis for Al data were

  15. Core Microbiome of Medicinal Plant Salvia miltiorrhiza Seed: A Rich Reservoir of Beneficial Microbes for Secondary Metabolism?

    Directory of Open Access Journals (Sweden)

    Haimin Chen

    2018-02-01

    Full Text Available Seed microbiome includes special endophytic or epiphytic microbial taxa associated with seeds, which affects seed germination, plant growth, and health. Here, we analyzed the core microbiome of 21 Salvia miltiorrhiza seeds from seven different geographic origins using 16S rDNA and ITS amplicon sequencing, followed by bioinformatics analysis. The whole bacterial microbiome was classified into 17 microbial phyla and 39 classes. Gammaproteobacteria (67.6%, Alphaproteobacteria (15.6%, Betaproteobacteria (2.6%, Sphingobacteria (5.0%, Bacilli (4.6%, and Actinobacteria (2.9% belonged to the core bacterial microbiome. Dothideomycetes comprised 94% of core fungal microbiome in S. miltiorrhiza seeds, and another two dominant classes were Leotiomycetes (3.0% and Tremellomycetes (2.0%. We found that terpenoid backbone biosynthesis, degradation of limonene, pinene, and geraniol, and prenyltransferases, were overrepresented in the core bacterial microbiome using phylogenetic examination of communities by reconstruction of unobserved states (PICRUSt software. We also found that the bacterial genera Pantoea, Pseudomonas, and Sphingomonas were enriched core taxa and overlapped among S. miltiorrhiza, maize, bean, and rice, while a fungal genus, Alternaria, was shared within S. miltiorrhiza, bean, and Brassicaceae families. These findings highlight that seed-associated microbiomeis an important component of plant microbiomes, which may be a gene reservoir for secondary metabolism in medicinal plants.

  16. Core Microbiome of Medicinal Plant Salvia miltiorrhiza Seed: A Rich Reservoir of Beneficial Microbes for Secondary Metabolism?

    Science.gov (United States)

    Chen, Haimin; Wu, Hongxia; Yan, Bin; Zhao, Hongguang; Liu, Fenghua; Zhang, Haihua; Sheng, Qing; Miao, Fang; Liang, Zongsuo

    2018-02-27

    Seed microbiome includes special endophytic or epiphytic microbial taxa associated with seeds, which affects seed germination, plant growth, and health. Here, we analyzed the core microbiome of 21 Salvia miltiorrhiza seeds from seven different geographic origins using 16S rDNA and ITS amplicon sequencing, followed by bioinformatics analysis. The whole bacterial microbiome was classified into 17 microbial phyla and 39 classes. Gammaproteobacteria (67.6%), Alphaproteobacteria (15.6%), Betaproteobacteria (2.6%), Sphingobacteria (5.0%), Bacilli (4.6%), and Actinobacteria (2.9%) belonged to the core bacterial microbiome. Dothideomycetes comprised 94% of core fungal microbiome in S. miltiorrhiza seeds, and another two dominant classes were Leotiomycetes (3.0%) and Tremellomycetes (2.0%). We found that terpenoid backbone biosynthesis, degradation of limonene, pinene, and geraniol, and prenyltransferases, were overrepresented in the core bacterial microbiome using phylogenetic examination of communities by reconstruction of unobserved states (PICRUSt) software. We also found that the bacterial genera Pantoea, Pseudomonas , and Sphingomonas were enriched core taxa and overlapped among S. miltiorrhiza , maize, bean, and rice, while a fungal genus, Alternaria , was shared within S. miltiorrhiza , bean, and Brassicaceae families. These findings highlight that seed-associated microbiomeis an important component of plant microbiomes, which may be a gene reservoir for secondary metabolism in medicinal plants.

  17. Sustainable Use of Reservoir Sediment through Partial Application in Building Material

    Directory of Open Access Journals (Sweden)

    Natalia Junakova

    2017-05-01

    Full Text Available Sediment, often considered a by-product of various activities within river basin management to be disposed of, or a pollutant to be controlled, is increasingly being acknowledged as a resource in need of management. The paper deals with the possibility of reusing sediment from two Slovak reservoirs (Klusov and Ruzin as an alternative raw material in concrete production. Concrete specimens were prepared by a combination of original reservoir sediment, reservoir sediment mechanically activated by dry milling, reservoir sediment mechanically activated by dry milling together with biomass incinerator fly-ash as a binder. To improve the strength properties of specimens, sodium hydroxide (NaOH was used as a sediment activator. Mixtures containing 40% of binder replacement by the above-mentioned combinations of original and treated sediments were tested for flexural and compressive strengths after 28, 90 and 365 days of curing. The results showed that the mixtures prepared from sediments milled without and with addition of fly ash as cement replacement satisfied the strength requirements for the compressive strength class C16/20 according to the European standard except the composites prepared with NaOH as the sediment activator. Addition of NaOH into composites in the concentration of 5 M as an activator of sediment indicated the negative impact on compressive and flexural strengths and thus NaOH was not an effective pozzolanic activator for sediments. This study reveals that the sediment may be considered as 40% cement substitution in building materials.

  18. Effect of wettability on scale-up of multiphase flow from core-scale to reservoir fine-grid-scale

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Y.C.; Mani, V.; Mohanty, K.K. [Univ. of Houston, TX (United States)

    1997-08-01

    Typical field simulation grid-blocks are internally heterogeneous. The objective of this work is to study how the wettability of the rock affects its scale-up of multiphase flow properties from core-scale to fine-grid reservoir simulation scale ({approximately} 10{prime} x 10{prime} x 5{prime}). Reservoir models need another level of upscaling to coarse-grid simulation scale, which is not addressed here. Heterogeneity is modeled here as a correlated random field parameterized in terms of its variance and two-point variogram. Variogram models of both finite (spherical) and infinite (fractal) correlation length are included as special cases. Local core-scale porosity, permeability, capillary pressure function, relative permeability functions, and initial water saturation are assumed to be correlated. Water injection is simulated and effective flow properties and flow equations are calculated. For strongly water-wet media, capillarity has a stabilizing/homogenizing effect on multiphase flow. For small variance in permeability, and for small correlation length, effective relative permeability can be described by capillary equilibrium models. At higher variance and moderate correlation length, the average flow can be described by a dynamic relative permeability. As the oil wettability increases, the capillary stabilizing effect decreases and the deviation from this average flow increases. For fractal fields with large variance in permeability, effective relative permeability is not adequate in describing the flow.

  19. Survey of melt interactions with core retention material

    International Nuclear Information System (INIS)

    Powers, D.A.

    1979-01-01

    A survey of the interactions of up to 220 kg stainless steel melts at 1973 0 K with the candidate core retention materials borax, firebrick, high alumina cement, and magnesia is described. Data collected for the interactions include rates of material erosion, aerosol generation, gas evolution, and upward heat flux. Borax acts as an ablative solid that rapidly quenches the melt. Firebrick is ablated by the steel melt at a rate of 8.2 x 10 -6 m/s. High alumina cement is found to be an attractive melt retention material especially if it can be used in the unhydrated form. Magnesia is also found to be an attractive material though it can be eroded by the molten oxides of steel

  20. Reservoir characterization using core, well log, and seismic data and intelligent software

    Science.gov (United States)

    Soto Becerra, Rodolfo

    We have developed intelligent software, Oilfield Intelligence (OI), as an engineering tool to improve the characterization of oil and gas reservoirs. OI integrates neural networks and multivariate statistical analysis. It is composed of five main subsystems: data input, preprocessing, architecture design, graphics design, and inference engine modules. More than 1,200 lines of programming code as M-files using the language MATLAB been written. The degree of success of many oil and gas drilling, completion, and production activities depends upon the accuracy of the models used in a reservoir description. Neural networks have been applied for identification of nonlinear systems in almost all scientific fields of humankind. Solving reservoir characterization problems is no exception. Neural networks have a number of attractive features that can help to extract and recognize underlying patterns, structures, and relationships among data. However, before developing a neural network model, we must solve the problem of dimensionality such as determining dominant and irrelevant variables. We can apply principal components and factor analysis to reduce the dimensionality and help the neural networks formulate more realistic models. We validated OI by obtaining confident models in three different oil field problems: (1) A neural network in-situ stress model using lithology and gamma ray logs for the Travis Peak formation of east Texas, (2) A neural network permeability model using porosity and gamma ray and a neural network pseudo-gamma ray log model using 3D seismic attributes for the reservoir VLE 196 Lamar field located in Block V of south-central Lake Maracaibo (Venezuela), and (3) Neural network primary ultimate oil recovery (PRUR), initial waterflooding ultimate oil recovery (IWUR), and infill drilling ultimate oil recovery (IDUR) models using reservoir parameters for San Andres and Clearfork carbonate formations in west Texas. In all cases, we compared the results from

  1. Understanding creep in sandstone reservoirs - theoretical deformation mechanism maps for pressure solution in granular materials

    Science.gov (United States)

    Hangx, Suzanne; Spiers, Christopher

    2014-05-01

    Subsurface exploitation of the Earth's natural resources removes the natural system from its chemical and physical equilibrium. As such, groundwater extraction and hydrocarbon production from subsurface reservoirs frequently causes surface subsidence and induces (micro)seismicity. These effects are not only a problem in onshore (e.g. Groningen, the Netherlands) and offshore hydrocarbon fields (e.g. Ekofisk, Norway), but also in urban areas with extensive groundwater pumping (e.g. Venice, Italy). It is known that fluid extraction inevitably leads to (poro)elastic compaction of reservoirs, hence subsidence and occasional fault reactivation, and causes significant technical, economic and ecological impact. However, such effects often exceed what is expected from purely elastic reservoir behaviour and may continue long after exploitation has ceased. This is most likely due to time-dependent compaction, or 'creep deformation', of such reservoirs, driven by the reduction in pore fluid pressure compared with the rock overburden. Given the societal and ecological impact of surface subsidence, as well as the current interest in developing geothermal energy and unconventional gas resources in densely populated areas, there is much need for obtaining better quantitative understanding of creep in sediments to improve the predictability of the impact of geo-energy and groundwater production. The key problem in developing a reliable, quantitative description of the creep behaviour of sediments, such as sands and sandstones, is that the operative deformation mechanisms are poorly known and poorly quantified. While grain-scale brittle fracturing plus intergranular sliding play an important role in the early stages of compaction, these time-independent, brittle-frictional processes give way to compaction creep on longer time-scales. Thermally-activated mass transfer processes, like pressure solution, can cause creep via dissolution of material at stressed grain contacts, grain

  2. New sacrificial material for ex-vessel core catcher

    Energy Technology Data Exchange (ETDEWEB)

    Komlev, Andrei A., E-mail: komlev@kth.se [Kungliga Tekniska Högskolan (KTH), AlbaNova University Centre, Nuclear Power Safety Division, Roslagstullsbacken 21, SE-106 91, Stockholm (Sweden); Almjashev, Vyacheslav I., E-mail: vac@mail.ru [A.P. Aleksandrov Research Institute of Technology, NITI, DSAR, Sosnovy Bor, 188540 (Russian Federation); Bechta, Sevostian V., E-mail: bechta@safety.sci.kth.se [Kungliga Tekniska Högskolan (KTH), AlbaNova University Centre, Roslagstullsbacken 21, SE-106 91, Stockholm (Sweden); Khabensky, Vladimir B., E-mail: vladimirkhabensky@gmail.com [A.P. Aleksandrov Research Institute of Technology, NITI, DSAR, Sosnovy Bor, 188540 (Russian Federation); Granovsky, Vladimir S., E-mail: gran@niti.ru [A.P. Aleksandrov Research Institute of Technology, NITI, DSAR, Sosnovy Bor, 188540 (Russian Federation); Gusarov, Victor V., E-mail: victor.v.gusarov@gmail.com [Ioffe Institute, 26 Polytekhnicheskaya Str., St. Petersburg, 194021 (Russian Federation)

    2015-12-15

    A new functional (sacrificial) material has been developed in the Fe{sub 2}O{sub 3}–SrO–Al{sub 2}O{sub 3}–CaO system based on strontium hexaferrite ceramic in concrete matrix. The method of producing SM has been advanced technologically; this technological effectiveness allows the SM to be used in ex-vessel core catchers with corium spreading as well as in crucible-type core catchers. Critical properties regarding the efficiency of SM in ex-vessel core catchers, such as porosity, pycnometric density, apparent density, solidus and liquidus temperatures, and water content have been measured. Suitable fractions of SrFe{sub 12}O{sub 19} and high alumina cement (HAC) were found in the SM based on thermodynamic analysis of the SM/corium interaction. The use of sacrificial steel as an additional heat adsorption component in the core catcher allowed us to increase the mass fraction range of SrFe{sub 12}O{sub 19} in the SM from 0.3−0.5 to 0.3–0.85. The activation temperature of the SM/corium interaction has been shown to correspond to the liquidus temperature of the local composition at the SM/corium interface. The calculated value of this temperature was 1716 °C. Analysis of phase transformations in the SrO–Fe{sub 2}O{sub 3} system revealed advantages of the SrFe{sub 12}O{sub 19}–based sacrificial material compared with the Fe{sub 2}O{sub 3}-contained material owing to the time proximity of SrFe{sub 12}O{sub 19} decomposition and corium interaction activation. - Highlights: • A sacrificial material (SM) was developed for ex-vessel core catcher. • Suitable proportions in the SrFe{sub 12}O{sub 19}–Al{sub 2}O{sub 3}·CaO–Fe system were determined. • Hydrogen release limitation was shown for ex-vessel corium retention with the SM. • Calculated temperature of the active initiation of corium/SM interaction is 1716 °C. • Functional properties of the SM were measured.

  3. Characteristics of carbon materials for core support of VHTR

    International Nuclear Information System (INIS)

    Kawakami, Haruo

    1984-01-01

    For the materials of the reactor bed of a high temperature gas-cooled experimental reactor, the compressive strength for supporting the weight of the core and the dimensional stability are required as well as the heat insulating performance. As a material for this purpose, at present carbon material is considered to be most promising. In this report, the results of having examined the applicability of the carbon materials of several foreign products to the material for the reactor bed are summarized. The materials examined were PG-41, ASR-0RB, ASR-1RB and P3 JHA-B, and the measurement of such main properties as heat conductivity and compressive strength and the stability test at 1000 deg C were carried out. Besides, as for the ASR-1RB, the dispersion of the property values in a large block of 980mm diameter and 300mm length close to the dimensions required for the actual reactor was examined. In the large block, some dispersion was observed in the density, heat conductivity, compressive strength and so on, but the degree was in the range of being allowable in the design. It was found that the ASR-0RB and ASR-1RB showed the high applicability as the reactor bed material. (Kako, I.)

  4. Technical Meeting on Liquid Metal Reactor Concepts: Core Design and Structural Materials. Working Material

    International Nuclear Information System (INIS)

    2013-01-01

    The objective of the TM on “Liquid metal reactor concept: core design and structural materials” was to present and discuss innovative liquid metal fast reactor (LMFR) core designs with special focus on the choice, development, testing and qualification of advanced reactor core structural materials. Main results arising from national and international R&D programmes and projects in the field were reviewed, and new activities to be carried out under the IAEA aegis were identified on the basis of the analysis of current research and technology gaps

  5. Molten LWR core material interactions with water and with concrete

    International Nuclear Information System (INIS)

    Dahlgren, D.A.; Buxton, L.D.; Muir, J.F.; Murfin, W.B.; Nelson, L.S.; Powers, D.A.

    1977-01-01

    Nuclear power reactors are designed and operated to minimize the possibility of fuel melting. Nevertheless, in order to assess the risks associated with reactor operation, a realistic assessment is required for postulated accident sequences in which melting occurs. To investigate the experimental basis of the fuel melt accident analyses, a comprehensive review was performed at Sandia Laboratories. The results of that study indicated several phenomenological areas where additional experimental data should be gathered to verify common assumptions made in risk studies. In particular, vapor explosions and molten core material/concrete interactions were identified for further study. Results of these studies are presented

  6. Standard Test Method for Shear Fatigue of Sandwich Core Materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2000-01-01

    1.1 This test method covers determination of the effect of repeated shear loads on sandwich core materials. 1.2 The values stated in SI units are to be regarded as the standard. The inch-pound units given may be approximate. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  7. Static analysis of material testing reactor cores:critical core calculations

    International Nuclear Information System (INIS)

    Nawaz, A. A.; Khan, R. F. H.; Ahmad, N.

    1999-01-01

    A methodology has been described to study the effect of number of fuel plates per fuel element on critical cores of Material Testing Reactors (MTR). When the number of fuel plates are varied in a fuel element by keeping the fuel loading per fuel element constant, the fuel density in the fuel plates varies. Due to this variation, the water channel width needs to be recalculated. For a given number of fuel plates, water channel width was determined by optimizing k i nfinity using a transport theory lattice code WIMS-D/4. The dimensions of fuel element and control fuel element were determined using this optimized water channel width. For the calculated dimensions, the critical cores were determined for the given number of fuel plates per fuel element by using three dimensional diffusion theory code CITATION. The optimization of water channel width gives rise to a channel width of 2.1 mm when the number of fuel plates is 23 with 290 g ''2''3''5U fuel loading which is the same as in the case of Pakistan Reactor-1 (PARR-1). Although the decrease in number of fuel element results in an increase in optimal water channel width but the thickness of standard fuel element (SFE) and control fuel element (CFE) decreases and it gives rise to compact critical and equilibrium cores. The criticality studies of PARR-1 are in good agreement with the predictions

  8. Glove material, reservoir formation, and dose affect glove permeation and subsequent skin penetration

    DEFF Research Database (Denmark)

    Nielsen, Jesper Bo; Sørensen, Jens Ahm

    2012-01-01

    Protective gloves are used to reduce dermal exposure when managing chemical exposures at the work place. Different glove materials may offer different degrees of protection. The present study combined the traditional ASTM (American Society for Testing and Materials) model with the Franz diffusion...... cell to evaluate overall penetration through glove and skin as well as the deposition in the different reservoirs. Benzoic acid was applied on latex or nitrile gloves placed on top of human skin. The amounts of chemical were quantified in the glove material, between glove and skin, within the skin......, and in the receptor chamber. Both glove materials reduce total penetration of benzoic acid, but nitrile gloves offer a significantly better protection than latex gloves. This difference was less pronounced at the higher of the two concentrations of benzoic acid applied. Thus, glove types that offer relevant...

  9. Watershed trend analysis and water-quality assessment using bottom-sediment cores from Cheney Reservoir, south-central Kansas

    Science.gov (United States)

    Pope, Larry M.

    1998-01-01

    An examination of Cheney Reservoir bottom sediment was conducted in August 1997 to describe long-term trends and document the occurrence of selected constituents at concentrations that may be detrimental to aquatic organisms. Average concentrations of total phosphorus in bottom-sediment cores ranged from 94 to 674 milligrams per kilogram and were statistically related to silt- and (or) clay-size particles. Results from selected sampling sites in Cheney Reservoir indicate an increasing trend in total phosphorus concentrations. This trend is probably of nonpoint-source origin and may be related to an increase in fertilizer sales in the area, which more than doubled between 1965 and 1996, and to livestock production. Few organochlorine compounds were detected in bottom-sediment samples from Cheney Reservoir. DDT, its degradation products DDD and DDE, and dieldrin had detectable concentrations in the seven samples that were analyzed. DDT and DDD were each detected in one sample at concentrations of 1.0 and 0.65 microgram per kilogram, respectively. By far, the most frequently detected organochlorine insecticide was DDE, which was detected in all seven samples, ranging in concentration from 0.31 to 1.3 micrograms per kilogram. A decreasing trend in DDE concentrations was evident in sediment-core data from one sampling site. Dieldrin was detected in one sample from each of two sampling sites at concentrations of 0.21 and 0.22 micrograms per kilogram. Polychlorinated biphenyls were not detected in any bottom-sediment sample analyzed. Selected organophosphate, chlorophenoxy-acid, triazine, and acetanilide pesticides were analyzed in 18 bottom-sediment samples. Of the 23 pesticides analyzed, only the acetanilide herbicide metolachlor was detected (in 22 percent of the samples). Seven bottom-sediment samples were analyzed for major metals and trace elements. The median and maximum concentrations of arsenic and chromium, the maximum concentration of copper, and all

  10. Dual stimuli responsive self-reporting material for chemical reservoir coating

    Science.gov (United States)

    Lee, Tae Hee; Song, Young Kyu; Park, Sun Hee; Park, Young Il; Noh, Seung Man; Kim, Jin Chul

    2018-03-01

    In this study, we introduce a novel dual stimuli responsive self-reporting thiol-epoxy thermoset (DSRTET) coatings which can detect both crack occurrence and pH variation. For crack detection, microcapsule containing tetraphenylethylene (TPE) which exhibits aggregation induced emission (AIE) effect was prepared via multi-step emulsion polymerization and dispersed in DSRTET coatings. For pH variation detection, commercial thymol blue as a pH indicator was added into the polymer matrix. The effect of microcapsule contents in DSRTET on their curing behavior, material properties, and crack sensitivity was characterized using an oscillatory rheology, rigid body pendulum test (RPT), nano-indentation test (NST), universal test machine (UTM) and scratch tester. It was revealed that crack sensitivity of DSRTET coatings was greatly influenced by material properties as well as microcapsule content. The color transition of DSRTET coatings in response to acid or base solution were quantitatively investigated using a multi-angle spectrophotometer after simple acid and base solution drop tests. The color of DSRTET coatings changed from a pale green to red for acidic solution and to blue for basic solution. Finally, The DSRTET used in this study was applied to laboratory scale chemical reservoirs in order to verify the potential as a dual stimuli response self-reporting coating which can detect both crack in coating material and chemical spill caused by the leakage or breakage of the reservoir part.

  11. Mineralogical controls on porosity and water chemistry during O2-SO2-CO2 reaction of CO2 storage reservoir and cap-rock core

    International Nuclear Information System (INIS)

    Pearce, Julie K.; Golab, Alexandra; Dawson, Grant K.W.; Knuefing, Lydia; Goodwin, Carley; Golding, Suzanne D.

    2016-01-01

    Reservoir and cap-rock core samples with variable lithology's representative of siliciclastic reservoirs used for CO 2 storage have been characterized and reacted at reservoir conditions with an impure CO 2 stream and low salinity brine. Cores from a target CO 2 storage site in Queensland, Australia were tested. Mineralogical controls on the resulting changes to porosity and water chemistry have been identified. The tested siliciclastic reservoir core samples can be grouped generally into three responses to impure CO 2 -brine reaction, dependent on mineralogy. The mineralogically clean quartzose reservoir cores had high porosities, with negligible change after reaction, in resolvable porosity or mineralogy, calculated using X-ray micro computed tomography and QEMSCAN. However, strong brine acidification and a high concentration of dissolved sulphate were generated in experiments owing to minimal mineral buffering. Also, the movement of kaolin has the potential to block pore throats and reduce permeability. The reaction of the impure CO 2 -brine with calcite-cemented cap-rock core samples caused the largest porosity changes after reaction through calcite dissolution; to the extent that one sample developed a connection of open pores that extended into the core sub-plug. This has the potential to both favor injectivity but also affect CO 2 migration. The dissolution of calcite caused the buffering of acidity resulting in no significant observable silicate dissolution. Clay-rich cap-rock core samples with minor amounts of carbonate minerals had only small changes after reaction. Created porosity appeared mainly disconnected. Changes were instead associated with decreases in density from Fe-leaching of chlorite or dissolution of minor amounts of carbonates and plagioclase. The interbedded sandstone and shale core also developed increased porosity parallel to bedding through dissolution of carbonates and reactive silicates in the sandy layers. Tight interbedded cap

  12. The lunar core can be a major reservoir for volatile elements S, Se, Te and Sb

    NARCIS (Netherlands)

    Steenstra, E.S.

    2017-01-01

    The Moon bears a striking compositional and isotopic resemblance to the bulk silicate Earth (BSE) for many elements, but is considered highly depleted in many volatile elements compared to BSE due to high-temperature volatile loss from Moon-forming materials in the Moon-forming giant impact and/ or

  13. Irradiation-Accelerated Corrosion of Reactor Core Materials. Final Report

    International Nuclear Information System (INIS)

    Jiao, Zhujie; Was, Gary; Bartels, David

    2015-01-01

    This project aims to understand how radiation accelerates corrosion of reactor core materials. The combination of high temperature, chemically aggressive coolants, a high radiation flux and mechanical stress poses a major challenge for the life extension of current light water reactors, as well as the success of most all GenIV concepts. Of these four drivers, the combination of radiation and corrosion places the most severe demands on materials, for which an understanding of the fundamental science is simply absent. Only a few experiments have been conducted to understand how corrosion occurs under irradiation, yet the limited data indicates that the effect is large; irradiation causes order of magnitude increases in corrosion rates. Without a firm understanding of the mechanisms by which radiation and corrosion interact in film formation, growth, breakdown and repair, the extension of the current LWR fleet beyond 60 years and the success of advanced nuclear energy systems are questionable. The proposed work will address the process of irradiation-accelerated corrosion that is important to all current and advanced reactor designs, but remains very poorly understood. An improved understanding of the role of irradiation in the corrosion process will provide the community with the tools to develop predictive models for in-reactor corrosion, and to address specific, important forms of corrosion such as irradiation assisted stress corrosion cracking.

  14. Irradiation-Accelerated Corrosion of Reactor Core Materials. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Jiao, Zhujie [Univ. of Michigan, Ann Arbor, MI (United States); Was, Gary [Univ. of Michigan, Ann Arbor, MI (United States); Bartels, David [Univ. of Notre Dame, IN (United States)

    2015-04-02

    This project aims to understand how radiation accelerates corrosion of reactor core materials. The combination of high temperature, chemically aggressive coolants, a high radiation flux and mechanical stress poses a major challenge for the life extension of current light water reactors, as well as the success of most all GenIV concepts. Of these four drivers, the combination of radiation and corrosion places the most severe demands on materials, for which an understanding of the fundamental science is simply absent. Only a few experiments have been conducted to understand how corrosion occurs under irradiation, yet the limited data indicates that the effect is large; irradiation causes order of magnitude increases in corrosion rates. Without a firm understanding of the mechanisms by which radiation and corrosion interact in film formation, growth, breakdown and repair, the extension of the current LWR fleet beyond 60 years and the success of advanced nuclear energy systems are questionable. The proposed work will address the process of irradiation-accelerated corrosion that is important to all current and advanced reactor designs, but remains very poorly understood. An improved understanding of the role of irradiation in the corrosion process will provide the community with the tools to develop predictive models for in-reactor corrosion, and to address specific, important forms of corrosion such as irradiation assisted stress corrosion cracking.

  15. Silica@layered double hydroxide core-shell hybrid materials.

    Science.gov (United States)

    Kwok, Wing L J; Crivoi, Dana-Georgiana; Chen, Chunping; Buffet, Jean-Charles; O'Hare, Dermot

    2017-12-19

    A series of silica@layered double hydroxides (SiO 2 @Mg 2 Al-CO 3 -AMO-LDHs) have been synthesised by in situ precipitation of Mg 2 Al-CO 3 -LDH at room temperature in the presence of amorphous spherical silica particles (∼500 nm). We have systematically investigated a number of synthetic parameters in order to evaluate their effects on the composition, morphological and physical properties of the isolated materials. Syntheses carried out at moderate stirring speeds (e.g. 500 rpm) were found to promote the formation of vertically aligned LDH platelets with respect to the silica surface. Addition rates of the metal solutions slower than 0.43 mmol h -1 were found to create a thicker LDH shell consisting of vertically aligned LDH platelets. When the metal solutions were added rapidly (0.86 mmol h -1 ), we observed that for both slow and fast stirring speeds the synthesised core-shell materials had thin LDH shells and the majority of the LDH precipitated independent of the silica, forming unbound "free" LDH.

  16. Comparison of the fractional power motor with cores made of various magnetic materials

    Science.gov (United States)

    Gmyrek, Zbigniew; Lefik, Marcin; Cavagnino, Andrea; Ferraris, Luca

    2017-12-01

    The optimization of the motor cores, coupled with new core shapes as well as powering the motor at high frequency are the primary reasons for the use of new materials. The utilization of new materials, like SMC (soft magnetic composite), reduce the core loss and/or provide quasi-isotropic core's properties in any magnetization direction. Moreover, the use of SMC materials allows for avoiding degradation of the material portions, resulting from punching process, thereby preventing the deterioration of operating parameters of the motor. The authors examine the impact of technological parameters on the properties of a new type of SMC material and analyze the possibility of its use as the core of the fractional power motor. The result of the work is an indication of the shape of the rotor core made of a new SMC material to achieve operational parameters similar to those that have a motor with a core made of laminations.

  17. Glove material, reservoir formation, and dose affect glove permeation and subsequent skin penetration.

    Science.gov (United States)

    Nielsen, Jesper Bo; Sørensen, Jens Ahm

    2012-02-15

    Protective gloves are used to reduce dermal exposure when managing chemical exposures at the work place. Different glove materials may offer different degrees of protection. The present study combined the traditional ASTM (American Society for Testing and Materials) model with the Franz diffusion cell to evaluate overall penetration through glove and skin as well as the deposition in the different reservoirs. Benzoic acid was applied on latex or nitrile gloves placed on top of human skin. The amounts of chemical were quantified in the glove material, between glove and skin, within the skin, and in the receptor chamber. Both glove materials reduce total penetration of benzoic acid, but nitrile gloves offer a significantly better protection than latex gloves. This difference was less pronounced at the higher of the two concentrations of benzoic acid applied. Thus, glove types that offer relevant protection at low concentrations does not necessarily give appropriate protection at high concentrations. Significant amounts of benzoic acid could be extracted from the glove materials after exposure. If a chemical is accumulated in the glove material, reuse of single-use gloves should be cautioned. The reuse of gloves is generally not to be recommended without effective decontamination. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Derivation of temperature dependent material properties of polymer foam core materials using optical extensometry

    OpenAIRE

    Dulieu-Barton, J.M.; Boyenval Langlois, C.; Thomsen, O.T.; Zhang, S.; Fruehmann, R.K.

    2010-01-01

    A methodology for determining the temperature dependence of Young’s modulus and Poisson’s ratio of polymer foams core materials is presented. The design of the test specimen is described in detail, covering the parasitic effects resulting from departures from the uniform strain condition. The measurement approach is based on a non-contact technique so that the behaviour of the complaint foam is not modified by the attachment of strain gauges or extensometers. Firstly experiments are con...

  19. Comparison of mechanical properties of five commercial dental core build-up materials.

    Science.gov (United States)

    Passos, Sheila P; Freitas, Anderson P; Jumaily, Sami; Santos, Maria Jacinta M C; Rizkalla, Amin S; Santos, Gildo C

    2013-01-01

    This study aimed to evaluate and compare the mechanical properties of five commercial core materials using fracture toughness (FT), Knoop hardness number (KHN), diametral tensile strength (DTS), and dynamic elastic moduli (DEM). Composite material specimens were produced (Rock Core, CosmeCore, ParaCore, MultiCore Flow, and Filtek Supreme Plus). The FT test (n = 15) was performed using notchless triangular prism (NTP) specimens. FT was determined using an Instron testing machine. KHN (n = 3) was evaluated using three indentations applied on each specimen. DTS test (n = 15) was measured using an Instron testing machine. The density. of the specimens (n = 3) was determined by water displacement method. Dynamic Young's, shear moduli, and Poisson's ratio (n = 3) were measured by an ultrasonic method. Statistical analysis was conducted using ANOVA and a Tukey B rank order test (P = 0.05). Rock Core presented the lowest FT values. Filtek Supreme Plus and CosmeCore exhibited significantly higher KHN values than the rest of the materials. CosmeCore had the highest DTS value, which was statistically significant only compared to Rock Core. For DEM, Filtek Supreme Plus exhibited significantly higher Young's and shear moduli than the rest of the materials (P < 0.05). Results demonstrated significant differences in the FT, KHN, and DTS values of the core build-up materials tested. According to the elastic behavior of the core composite materials, Rock Core had the lowest Young's values.

  20. Collection, analysis, and age-dating of sediment cores from 56 U.S. lakes and reservoirs sampled by the U.S. Geological Survey, 1992-2001

    Science.gov (United States)

    Van Metre, Peter; Wilson, Jennifer T.; Fuller, Christopher C.; Callender, Edward; Mahler, Barbara J.

    2004-01-01

    The U.S. Geological Survey Reconstructed Trends National Synthesis study collected sediment cores from 56 lakes and reservoirs between 1992 and 2001 across the United States. Most of the sampling was conducted as part of the National Water-Quality Assessment (NAWQA) Program. The primary objective of the study was to determine trends in particle-associated contaminants in response to urbanization; 47 of the 56 lakes are in or near one of 20 U.S. cities. Sampling was done with gravity, piston, and box corers from boats and push cores from boats or by wading, depending on the depth of water and thickness of sediment being sampled. Chemical analyses included major and trace elements, organochlorine pesticides, polychlorinated biphenyls, polycyclic aromatic hydrocarbons, cesium-137, and lead-210. Age-dating of the cores was done on the basis of radionuclide analyses and the position of the pre-reservoir land surface in the reservoir and, in a few cases, other chemical or lithologic depth-date markers. Dates were assigned in many cores on the basis of assumed constant mass accumulation between known depth-date markers. Dates assigned were supported using a variety of other date markers including first occurrence and peak concentrations of DDT and polychlorinated biphenyls and peak concentration of lead. A qualitative rating was assigned to each core on the basis of professional judgment to indicate the reliability of age assignments. A total of 122 cores were collected from the 56 lakes and age dates were assigned to 113 of them, representing 54 of the 56 lakes. Seventy-four of the 122 cores (61 percent) received a good rating for the assigned age dates, 28 cores (23 percent) a fair rating, and 11 cores (9 percent) a poor rating; nine cores (7 percent) had no dates assigned. An analysis of the influence of environmental factors on the apparent quality of age-dating of the cores concluded that the most important factor was the mass accumulation rate (MAR) of sediment: the

  1. Comparative evaluation of compressive strength and flexural strength of conventional core materials with nanohybrid composite resin core material an in vitro study.

    Science.gov (United States)

    Jayanthi, Narasimha; Vinod, V

    2013-09-01

    Several dental materials have been used for core build-up procedures. Most of these materials were not specifically developed for this purpose, but as a consequence of their properties, have found application in core build-up procedures. Improvements in composites and the development of nanocomposites have led to their use as a core build up material due to their superior mechanical properties, optical properties and ease of handling. However it is not clear if they have better mechanical properties than the conventional core build up materials like amalgam, GIC and dual cure composite core build up material. The strength of the core material is very important and this study was undertaken to compare the mechanical properties of materials used for direct core foundations. The differences between the compressive strength and flexural strength of Filtek Z350 nanocomposite with conventional core build up materials like Amalgam, Vitremer GIC and Fluorocore were tested. Cylindrical plexi glass split molds of dimension 6 ± 1 mm [height] x4 ± 1 mm [diameter] were used to fabricate 15 samples of each core material for testing the compressive strength and rectangular plexi glass split molds of dimension 25 ± 1 mm [length] x 2 ± 1 mm[height] x2 ± 1 mm [width] used for fabricating samples for flexural strength. The samples were stored a water bath at 250 °C for 24 h before testing. The samples were tested using a Universal Instron testing machine. The results of the study showed that Fluorocore had the highest compressive strength and flexural strength followed by Filtek Z350 [nanocomposite] Amalgam had the least flexural strength and Vitremer GIC had the least compressive strength. Thus flurocore and nanocomposite are stronger than other core build up materials and hence should be preferred over other conventional core build up materials in extensively damaged teeth.

  2. MTR (Materials Testing Reactors) cores fuel management. Application of a low enrichment reactor for the equilibrium and transitory core calculation

    International Nuclear Information System (INIS)

    Relloso, J.M.

    1990-01-01

    This work describes a methodology to define the equilibrium core and a MTR (Materials Testing Reactors) type reactor's fuel management upon multiple boundary conditions, such as: end cycle and permitted maximum reactivities, burn-up extraction and maximun number of movements by rechange. The methodology proposed allows to determine the best options through conceptual relations, prior to a detailed calculation with the core code, reducing the test number with these codes and minimizing in this way CPU cost. The way to better systematized search of transient cores from the first one to the equilibrium one is presented. (Author) [es

  3. Assessment of Cr pollution in tributary sediment cores in the Three Gorges Reservoir combining geochemical baseline and in situ DGT.

    Science.gov (United States)

    Gao, Bo; Gao, Li; Xu, Dongyu; Zhou, Yang; Lu, Jin

    2018-07-01

    The mobility and transfer of trace metals in sediments are vital to understanding trace metals environmental behavior in water environment. However, as a predominant aquatic carcinogen, an effective method for assessing the release and deposition for Cr at the sediment-water interface (SWI) is still not clearly understood. Here we established a comprehensive methodology to evaluate the release risk of Cr at the SWI combining regional geochemical baseline (RGB) and diffusive gradients in thin films (DGT). Sediment cores and water samples were collected in the two tributaries and mainstream of the Three Gorges Reservoir, which is the world's largest man-made hydroelectric station. Results showed that the calculated Cr carcinogenic risks in surface water did not exceed US EPA maximum recommended level. The RGB of Cr (85.53 ± 14.44 mg/kg) were calculated and the differentials between Cr concentration and RGB in surface sediments showed the average anthropogenic contribution rate was 6.03% and the upstream of Meixi River (MX-S) and mainstream were influenced by anthropogenic activities. The net diffusive flux using DGT showed that Cr in the midstream of Caotang River and MX had the potential to move upwards into the overlying water. Furthermore, combining the results of differential (Cr concentration vs. RGB) and the net flux, MX-S was the only site with a risk of Cr release. To the best of our knowledge, this study is the first attempt to combine RGB and DGT to scientifically assess metal release at SWI and provided a new perspective to comprehensively assess metal pollution in water environment. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Reservoir age variations and stable isotope values of bulk sediment in a core from the Limfjord, Denmark

    DEFF Research Database (Denmark)

    Philippsen, Bente; Olsen, Jesper; Rasmussen, Peter

    thousand years is possible for freshwater with a high content of dissolved carbonate. On the other hand, freshwater without a significant content of 14C-dead carbon does not have a reservoir age. In coastal waters, the different water sources mix and produce highly variable reservoir ages. Due to Holocene...... on radiocarbon dating of shells and on stable isotope measurements of bulk sediment from 7400 to 1300 cal BP. Reservoir ages in coastal waters and estuaries can differ considerably from the global model ocean. The seas around Denmark have a reservoir age of c. 400 years, while a hardwater effect of a few...... relative sea level fluctuations, caused by the interplay of eustatic sea level changes and isostasy, the Limfjord had varying connections to the sea. As the relative proportion of marine and fresh water varied with time, the reservoir age for the Limfjord is also expected to vary. Radiocarbon datings...

  5. Mixing core material into the envelopes of red grants

    International Nuclear Information System (INIS)

    Deupree, R.G.

    1986-01-01

    A discussion is presented of calculations of four core helium flashes in red giant stars. The starting point for these calculations is a point source explosion on the polar axis of a two-dimensional finite difference grid. The amount of residue of the core helium flash mixed into and above the hydrogen shell is calculated at four temperatures for the elements carbon, oxygen, neon, magnesium, silicon, and sulfur. 7 refs., 1 tab

  6. A finite element thermal analysis of various dowel and core materials

    OpenAIRE

    Shanti Varghese; Padma Ariga; T V Padmanaban; R Subramanian

    2012-01-01

    Aim: Thermal analysis of the temperature and stress distribution of parallel sided, threaded and non-threaded dowels and core materials under thermal loading within a maxillary central incisor using a three dimensional finite element study. Materials and Methods: 3D models of endodontically treated maxillary central incisor with parallel sided, threaded and non- threaded post and core materials were simulated using the ANSYS software. Materials simulated were parallel sided cast gold post...

  7. Electrical properties of spherical dipole antennas with lossy material cores

    DEFF Research Database (Denmark)

    Hansen, Troels Vejle; Kim, Oleksiy S.; Breinbjerg, Olav

    2012-01-01

    and all the provided expressions are exact and valid for arbitrary core sizes, permeability, permittivity, electric and magnetic loss tangents. Arbitrary dispersion models for both permeability and permittivity can be applied. In addition, we present an investigation for an antenna of fixed electrical...... size and permittivity, focusing on the effects of magnetic core losses for a simple magnetic dispersion model, to illustrate how stored energies, efficiency and quality factor are affected. This shows that large magnetic losses can be beneficial, as these can produce a relatively high efficiency....

  8. Upper Khami reservoir study using microscopic thin sections, core and mud lost data and modeling, Bibi Hakimeh oil field

    Directory of Open Access Journals (Sweden)

    B., Soleimani,

    2012-01-01

    Full Text Available The present study is an evaluation of diagenetic processes and reservoir quality of the upper Khami Group in Bibi Hakimeh oil field. The Khami Group is divided into upper (Fahliyan, Gadvan and Dariyan formations and lower parts (Surmeh and Haith formations. Lithologically, Fahliyan and Dariyan formations and Khalij Member of the Gadvan Formation are carbonate and Gadvan Formation is shale. The determined diagenetic processes are dolomitization, glauconitization, anhydritization, mechanical compaction and stylolitization, chertification, pyritization in the upper Khami. Reservoir geological model for describing the structure and fault effects, iso-grade mud loss and fracture maps were constructed by reservoir management system (RMS software. The results revealed that fractures development and as well as the effect of diagenetic processes such as dolomitization and dissolution seem to have increased the reservoir quality. There is good development of fractures in this reservoir. In general, existence of fractures and effects of processes such as dolomitization and dissolution seem to increase the reservoir quality in this field.

  9. Progress in High-Capacity Core-Shell Cathode Materials for Rechargeable Lithium Batteries.

    Science.gov (United States)

    Myung, Seung-Taek; Noh, Hyung-Joo; Yoon, Sung-June; Lee, Eung-Ju; Sun, Yang-Kook

    2014-02-20

    High-energy-density rechargeable batteries are needed to fulfill various demands such as self-monitoring analysis and reporting technology (SMART) devices, energy storage systems, and (hybrid) electric vehicles. As a result, high-energy electrode materials enabling a long cycle life and reliable safety need to be developed. To ensure these requirements, new material chemistries can be derived from combinations of at least two compounds in a secondary particle with varying chemical composition and primary particle morphologies having a core-shell structure and spherical cathode-active materials, specifically a nanoparticle core and shell, nanoparticle core and nanorod shell, and nanorod core and shell. To this end, several layer core-shell cathode materials were developed to ensure high capacity, reliability, and safety.

  10. Application of erosion-control materials and spontaneous vegetation in the protection of reservoirs in southern and eastern Serbia

    Directory of Open Access Journals (Sweden)

    Matić Vjačeslava

    2009-01-01

    Full Text Available The quality and stability of erosion-control materials in protection of reservoirs in Southern and Eastern Serbia have been examined both in the field and in accredited laboratories in our country. Field investigations have been carried out over a period of 15 years in Eastern Serbia and for up to 30 years in Southern Serbia, and they are still being conducted by monitoring the state and possible damage of consolidation-retention check dams, walls, and other erosion-control structures. The materials used in protection of the Selova and Grlište Reservoirs are typical construction materials, such as resistant natural stone, concrete of the BI group, i.e., MB 20, aggregate, synthetic elements, etc. Long-term monitoring of their state and minor deformations has shown that the materials were well-chosen and stable, and that there has been no significant damage, except for some minor crumbling and smaller cracks due to negligible scouring. This is all the result of prior thorough empirical and laboratory testing of applied materials, which helped to achieve stability and functionality of structures erected to prevent silting-up of the reservoir. Such a state has contributed to stabilization of erosion processes and reduction of sediment quantities, improvement of water quality, and advancement of the autochthonous vegetation (Salix L., Cornus L., Quercus L.. Vegetation has further mitigated erosion, decreased floods, and consolidated the structures, thereby improving the ecological quality of the catchments as well as the entire study area.

  11. Reactor Structure Materials: Corrosion of Reactor Core Internals

    International Nuclear Information System (INIS)

    Van Dyck, S.

    2000-01-01

    The objectives of SCK-CEN's R and D programme on the corrosion of reactor core internals are: (1) to gain mechanistic insight into the Irradition Assisted Stress Corrosion Cracking (IASCC) phenomenon by studying the influence of separate parameters in well controlled experiments; (2) to develop and validate a predictive capability on IASCC by model description and (3) to define and validate countermeasures and monitoring techniques for application in reactors. Progress and achievements in 1999 are described

  12. Standard Test Method for Dimensional Stability of Sandwich Core Materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2002-01-01

    1.1 This test method covers the determination of the sandwich core dimensional stability in the two plan dimensions. 1.2 The values stated in SI units are to be regarded as the standard. The inch-pound units given may be approximate. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  13. The influence of different core material on the FEA-determined stress distribution in dental crowns.

    Science.gov (United States)

    De Jager, Niek; de Kler, Marcel; van der Zel, Jef M

    2006-03-01

    All ceramic restorations without metal have great advantages in their biocompatibility and aesthetic aspects. With the introduction of new core materials, the cores are sufficiently strong to produce long lasting all-ceramic restorations; however, the stresses in the veneering porcelain could still determine the longevity. The objective of this study was to evaluate, by finite element analysis (FEA), the influence of different core materials on the stress distribution in dental crowns. The model of a multi-layer all-ceramic crown for posterior tooth 46 produced with CAD-CAM-technology was translated into a three-dimensional FEA program. This crown model was made with gold, zirconia, and alumina-based porcelain core and their matching veneering porcelains. The stress distribution due to the combined influences of bite forces, residual stresses caused by the difference in expansion coefficient of the core material and the veneering porcelain, and the influence of shrinkage of the cement was investigated. Stiffer core material does not always for various reasons result in lower stresses in the veneering porcelain. This study indicates that the actual distribution of the tensile stresses and the design of restorations must be taken into account; otherwise, the significant contribution of stronger and tougher core materials to the performance of all-ceramic restorations may be offset by the weaker veneering porcelain.

  14. Two-phase flow visualization under reservoir conditions for highly heterogeneous conglomerate rock: A core-scale study for geologic carbon storage.

    Science.gov (United States)

    Kim, Kue-Young; Oh, Junho; Han, Weon Shik; Park, Kwon Gyu; Shinn, Young Jae; Park, Eungyu

    2018-03-20

    Geologic storage of carbon dioxide (CO 2 ) is considered a viable strategy for significantly reducing anthropogenic CO 2 emissions into the atmosphere; however, understanding the flow mechanisms in various geological formations is essential for safe storage using this technique. This study presents, for the first time, a two-phase (CO 2 and brine) flow visualization under reservoir conditions (10 MPa, 50 °C) for a highly heterogeneous conglomerate core obtained from a real CO 2 storage site. Rock heterogeneity and the porosity variation characteristics were evaluated using X-ray computed tomography (CT). Multiphase flow tests with an in-situ imaging technology revealed three distinct CO 2 saturation distributions (from homogeneous to non-uniform) dependent on compositional complexity. Dense discontinuity networks within clasts provided well-connected pathways for CO 2 flow, potentially helping to reduce overpressure. Two flow tests, one under capillary-dominated conditions and the other in a transition regime between the capillary and viscous limits, indicated that greater injection rates (potential causes of reservoir overpressure) could be significantly reduced without substantially altering the total stored CO 2 mass. Finally, the capillary storage capacity of the reservoir was calculated. Capacity ranged between 0.5 and 4.5%, depending on the initial CO 2 saturation.

  15. The Effect of Cyclic Loading on the Compressive Strength of Core Build-Up Materials.

    Science.gov (United States)

    Zankuli, Muayed A; Silikas, Nick; Devlin, Hugh

    2015-01-15

    To evaluate the effect of cyclic loading on compressive strength of core build-up materials. Four dual-cured composites (Core.X Flow, Grandio Core, Bright Flow Core, Spee-Dee) and one light-cured reinforced resin-modified glass ionomer (Fuji II LC) were tested. One hundred cylindrical specimens (4 mm × 6 mm) were prepared. Each material had two groups (ten specimens to be tested under static loading and ten specimens to be tested after cyclic loading). The specimens were stored wet, and after 30 days, one group of each material was cyclically loaded (for 250,000 cycles with a frequency of 1.6 Hz under stress load of 68.6 N) in a chewing simulator CS-4.2. Then specimens were subjected to static compressive loading until failure in a universal testing machine. Mean compressive strength values before cycling ranged from 144 MPa (15.8) for Fuji II LC to 277 MPa (23.2) for Grandio Core. Independent t-test showed no statistically significant difference (p > 0.05) in the compressive strength of each material before and after cycling (p = 0.7 Grandio Core, p = 0.3 Core.X Flow, p = 0.6 Bright Flow Core, p = 0.2 Spee-Dee, p = 0.6 Fuji II LC); however, there was a statistically significant difference between the materials when comparing before and after cycling. All tested materials showed no reduction in the compressive strength after cycling. Therefore, the tested materials can survive 1 year in service without a reduction in compressive strength. © 2015 by the American College of Prosthodontists.

  16. Nematic biaxiality in a bent-core material

    Science.gov (United States)

    Yoon, Hyung Guen; Kang, Shin-Woong; Dong, Ronald Y.; Marini, Alberto; Suresh, Kattera A.; Srinivasarao, Mohan; Kumar, Satyendra

    2010-05-01

    The results of a recent investigation of the nematic biaxiality in a bent-core mesogen (A131) are in apparent disagreement with earlier claims. Samples of mesogen A131 used in the two studies were investigated with polarized optical microscopy, conoscopy, carbon-13 NMR, and crossover frequency measurements. The results demonstrate that textural changes associated with the growth of biaxial nematic order appear at ˜149°C . The Maltese cross observed in the conoscopic figure gradually splits into two isogyres at lower temperatures indicating phase biaxiality. Presence of the uniaxial to biaxial nematic phase transition is further confirmed by temperature trends of local order parameters based on C13 chemical shifts in NMR experiments. Frequency switching measurements also clearly reveal a transition at 149°C . Differences between the two reports appear to be related to the presence of solvent, impurities, and/or adsorbed gases in samples of A131 used in the study of Van Le [Phys. Rev. E 79, 030701 (2009)].

  17. Diametral tensile and compressive strengths of several types of core materials.

    Science.gov (United States)

    Yüzügüllü, Bulem; Çiftçi, Yalçnı; Saygılı, Gülbin; Canay, Şenay

    2008-02-01

    Compressive and diametral tensile strengths (DTSs) of core materials are thought to be important, because cores usually replace a large bulk of tooth structure and should provide sufficient strength to resist intraoral tensile and compressive forces. This study was undertaken to compare the mechanical properties of materials used for direct core foundations. The differences between the compressive and DTSs of six core materials, including Duralloy (high-copper amalgam), Grandio (visible light-cured nanohybrid resin composite), Admira (organically modified ceramic), Filtek P60 (packable composite resin), Rebilda DC (dual-cure adhesive core material), and Argion Molar (silver-reinforced glass ionomer cement), were tested. A total of 120 specimens, half for the compressive strength (CS) test (6 mm in height, 4 mm in diameter) and the other half for the DTS test (6 mm in diameter, 3 mm in thickness), were prepared. The specimens were stored at room temperature in distilled water for 7 days. The Lloyd testing machine was used to load the specimens at a crosshead speed 0.5 cm/min, and the strength values were determined in MPa. The compressive and DTS test values (in MPa), respectively, of the materials were: Admira (361, 44); Filtek P60 (331, 55); Grandio (294, 53); Rebilda DC (279, 42); Duralloy (184, 40); and Argion Molar (107, 9). Kruskal-Wallis test was computed, and multiple comparisons test discerned many differences among materials (p Grandio), and organically-modified ceramic (Admira) had higher compressive and DTS values than the other materials.

  18. Repair bond strength of dual-cured resin composite core buildup materials.

    Science.gov (United States)

    El-Deeb, Heba A; Ghalab, Radwa M; Elsayed Akah, Mai M; Mobarak, Enas H

    2016-03-01

    The reparability of dual-cured resin composite core buildup materials using a light-cured one following one week or three months storage, prior to repair was evaluated. Two different dual-cured resin composites; Cosmecore™ DC automix and Clearfil™ DC automix core buildup materials and a light-cured nanofilled resin composite; Filtek™ Z350 XT were used. Substrate specimens were prepared (n = 12/each substrate material) and stored in artificial saliva at 37 °C either for one week or three months. Afterward, all specimens were ground flat, etched using Scotchbond™ phosphoric acid etchant and received Single Bond Universal adhesive system according to the manufacturers' instructions. The light-cured nanofilled resin composite (Filtek™ Z350 XT) was used as a repair material buildup. To determine the cohesive strength of each solid substrate material, additional specimens from each core material (n = 12) were prepared and stored for the same periods. Five sticks (0.8 ± 0.01 mm(2)) were obtained from each specimen (30 sticks/group) for microtensile bond strength (μTBS) testing. Modes of failure were also determined. Two-way ANOVA revealed a significant effect for the core materials but not for the storage periods or their interaction. After one week, dual-cured resin composite core buildup materials (Cosmecore™ DC and Clearfil™ DC) achieved significantly higher repair μTBS than the light-cured nanofilled resin composite (Filtek™ Z350 XT). However, Clearfil™ DC revealed the highest value, then Cosmecore™ DC and Filtek™ Z350 XT, following storage for 3-month. Repair strength values recovered 64-86% of the cohesive strengths of solid substrate materials. The predominant mode of failure was the mixed type. Dual-cured resin composite core buildup materials revealed acceptable repair bond strength values even after 3-month storage.

  19. Understanding creep in sandstone reservoirs – theoretical deformation mechanism maps for pressure solution in granular materials

    NARCIS (Netherlands)

    Hangx, Suzanne; Spiers, Christopher

    Subsurface exploitation of the Earth’s natural resources removes the natural system from its chemical and physical equilibrium. As such, groundwater extraction and hydrocarbon production from subsurface reservoirs frequently causes surface subsidence and induces (micro)seismicity. These effects are

  20. Synthesis of suitable SiO2 nano particles as the core in core-shell nanostructured materials.

    Science.gov (United States)

    Ghahari, Mehdi; Aghababazadeh, Roya; Ebadzadeh, Touradj; Mirhabibi, Alireza; Brydson, Rik; Fabbri, Paola; Najafi, Farhod

    2011-06-01

    The effect of surfactant on the luminescent intensity of SiO2 @Y2O3:Eu3+ particles with a core shell structure is described. Core-shell particles are used in phosphor materials and employing spherical particles with a narrow size distribution is vital for the enhancement of luminescent properties. Three kinds of different surfactants were used to synthesis SiO2 nano particles via a sol gel process. The results demonstrated that comb polycarboxylic acid surfactant had a significant influence on the morphology and particle size distribution. Somehow, particles with 100 nm size and narrow size distribution were produced. These particles had relatively uniform packing, unlike particles produced with other surfactants or without surfactant which had irregular assembly. The photoluminescence intensity of SiO2 @Y2O3:Eu3+ particles that was synthesized by comb polycarboxylic acid surfactant was higher than those which were produced without surfactant.

  1. The effect of thermal change on various dowel-and-core restorative materials.

    Science.gov (United States)

    Yang, H S; Lang, L A; Guckes, A D; Felton, D A

    2001-07-01

    Severe thermal stresses caused by food-induced temperature changes may result in dowel-and-core failure. This study investigated the influence of thermal stresses on various combinations of dowel-and-core materials of a restored endodontically treated incisor. A 2-dimensional finite element model was constructed in a labiolingual cross-sectional view of a maxillary central incisor, a dowel, a core, and the supporting tissues to investigate thermal stress distribution. Four combinations of dowel-and-core materials were used: (1) gold/gold, (2) stainless steel/resin composite, (3) stainless steel/amalgam, and (4) carbon fiber-reinforced composite/resin composite. For thermal analysis, a cold irritant (0 degrees C) was applied on the outer surface of a metal-ceramic crown for 7 seconds. The metal dowel and core generated lower thermal stresses in the restorations and dentin than the nonmetallic dowel and cores. Stress level is closely related to the degree of thermal gradient. The nonmetallic dowel and cores generated greater thermal stresses than metal dowel and cores.

  2. Comparative study of mechanical properties of direct core build-up materials

    Directory of Open Access Journals (Sweden)

    Girish Kumar

    2015-01-01

    Full Text Available Background and Objectives: The strength greatly influences the selection of core material because core must withstand forces due to mastication and para-function for many years. This study was conducted to evaluate certain mechanical properties of commonly used materials for direct core build-up, including visible light cured composite, polyacid modified composite, resin modified glass ionomer, high copper amalgam, and silver cermet cement. Materials and Methods: All the materials were manipulated according to the manufacturer′s recommendations and standard test specimens were prepared. A universal testing machine at different cross-head speed was used to determine all the four mechanical properties. Mean compressive strength, diametral tensile strength, flexural strength, and elastic modulus with standard deviations were calculated. Multiple comparisons of the materials were also done. Results: Considerable differences in compressive strength, diametral tensile strength, and flexural strength were observed. Visible light cured composite showed relatively high compressive strength, diametral tensile strength, and flexural strength compared with the other tested materials. Amalgam showed the highest value for elastic modulus. Silver cermet showed less value for all the properties except for elastic modulus. Conclusions: Strength is one of the most important criteria for selection of a core material. Stronger materials better resist deformation and fracture provide more equitable stress distribution, greater stability, and greater probability of clinical success.

  3. A finite element thermal analysis of various dowel and core materials.

    Science.gov (United States)

    Varghese, Shanti; Ariga, Padma; Padmanaban, T V; Subramanian, R

    2012-01-01

    Thermal analysis of the temperature and stress distribution of parallel sided, threaded and non-threaded dowels and core materials under thermal loading within a maxillary central incisor using a three dimensional finite element study. 3D models of endodontically treated maxillary central incisor with parallel sided, threaded and non- threaded post and core materials were simulated using the ANSYS software. Materials simulated were parallel sided cast gold post and core, parallel sided fibre reinforced composite (FRC) post and core, and parallel sided, threaded, prefabricated stainless steel post and amalgam core. Thermal loads simulating hot (60 degree C/ 333K) and cold (15 degree C/288K) liquid were applied for 15 seconds at the incisal edge. The temperature changes at the selected nodes were obtained on the various post and core materials, interface between post and dentin, interface between core and dentin, within the dentin and within the cement layer. Temperature and stress distribution pattern were represented in numerical and color coding and results interpreted. Thermal stresses arises as a result of temperature changes. A decreased temperature gradient of the metallic dowels and core (T1 hot - 0.002K, T3 hot - 1.071K, T1 cold -0.99K, T3 cold - 0K) were obtained than that of the FRC dowel and core of 1.982K(hot) and1.55K(cold) respectively due to the higher thermal conductivity of the metals. Higher thermal stress values of 3.567 Mpa(hot) and 3.092 Mpa(cold) respectively were obtained for the FRC dowels and higher stress values of 39.679 Mpa(hot) and 57.855 Mpa(cold) respectively were also obtained for the FRC cores. These values indicated that thermal stresses of the FRC dowel and core were greater than that of cast gold dowel and core and prefabricated stainless steel dowel and amalgam core due to its high coefficient of thermal expansion. Maximum stress values of the FRC dowel and core of 1.87 Mpa(hot) and 2.57 Mpa(cold) respectively were also generated

  4. NASA CORE: Central Operation of Resources for Educators-Educational Materials Catalog

    Science.gov (United States)

    1998-01-01

    The NASA Central Operation of Resources for Educators (CORE), established in cooperation with Lorain County Joint Vocational School, serves as the worldwide distribution center for NASA-produced educational materials. For a minimal charge, CORE will provide a valuable service to educators unable to visit one of the NASA Educator Resource Centers by making NASA educational audiovisual materials available through its mail order service. Through CORE's distribution network, the public has access to more than 200 videocassette, slide, and CD-ROM programs, chronicling NASA!s state-of-the-art research and technology. Through the use of these curriculum supplement materials, teachers can provide their students with the latest in aerospace information. NASAs educational materials on aeronautics and space provide a springboard for classroom discussion of life science, physical science, astronomy, energy, Earth resources, environment, mathematics, and career education.

  5. Flexural strength of In-Ceram alumina and In-Ceram zirconia core materials.

    Science.gov (United States)

    Chong, Kok-Heng; Chai, John; Takahashi, Yutaka; Wozniak, Wayne

    2002-01-01

    The study compared the flexural strength of In-Ceram alumina and In-Ceram zirconia systems. The probability of failure of the two glass-infiltrated ceramic core materials was analyzed with and without lamination with Vitadur-alpha porcelain. Ten uniform beams of core materials as well as 10 beams of laminated core materials were fabricated for In-Ceram alumina and In-Ceram zirconia. The samples were subjected to three-point bending tests. Flexural strength for both ceramic core materials was determined with and without their porcelain laminations. The strength data were analyzed using the Weibull method. Modes of failure for both systems were determined using scanning electron micrography. The strength of the In-Ceram zirconia system was significantly higher than In-Ceram alumina when comparing their core materials with and without porcelain lamination. The failure mode for both systems was predominantly transgranular fracture of alumina platelets. In-Ceram zirconia demonstrated higher flexural strength than In-Ceram alumina.

  6. Alternative Hybrid Core Material For Vacuum Insulation Panels Silica-Fly Ash-Glass Fiber

    Directory of Open Access Journals (Sweden)

    Desire Emefa Awuye

    2017-11-01

    Full Text Available Vacuum insulation panels one of the most promising insulation materials consisting of an evacuated core material an air tight envelope and in special cases an absorbent known as getter. However despite its outstanding properties it faces some challenges such as relatively high cost and quite a short service life which can be attributed to the core material used. In this paper Hybrid core materials HCM consisting of various percentages of fly ash fumed silica and glass fiber were used as a core material for vacuum insulation panels and the composition ratio vs thermal conductivity were investigated to ascertain the optimum composition ratio that showed the lowest thermal conductivity and best insulation properties. This was to produce VIPs at a relatively cheaper cost. The optimum ratio of the HCM that showed the best insulation properties including lower thermal conductivity is that of 65 fly ash FA 30 fumed silica FS and 5 glass fiber GF. The HCM produced exhibited similar qualities as that of silica powder core VIPs. Even though produced at a relatively lower cost the insulation properties were not compromised. Furthermore the thermal conductivity of each of the VIPs from the HCMs prepared were measured after undergoing a temperature stress of 60 C for 6 months.

  7. Core-Shell Structured Electro- and Magneto-Responsive Materials: Fabrication and Characteristics

    Directory of Open Access Journals (Sweden)

    Hyoung Jin Choi

    2014-11-01

    Full Text Available Core-shell structured electrorheological (ER and magnetorheological (MR particles have attracted increasing interest owing to their outstanding field-responsive properties, including morphology, chemical and dispersion stability, and rheological characteristics of shear stress and yield stress. This study covers recent progress in the preparation of core-shell structured materials as well as their critical characteristics and advantages. Broad emphasises from the synthetic strategy of various core-shell particles to their feature behaviours in the magnetic and electric fields have been elaborated.

  8. Evidence of residual core material from the moon-forming impactor

    Science.gov (United States)

    Helffrich, George; Wood, Bernard

    2015-04-01

    Earth was accreted from smaller bodies initially dispersed over a wide range of heliocentric distances (Albarède, 2009; Morbidelli et al. 2012). Models of their assembly include timing constraints from short-lived isotopic systems (W-Hf (Allègre et al. 2008), Ag-Pd (Schönbächler et al. 2010)), physical condition constraints from metal-silicate element partitioning (W, Mo, Ni, Co, Cr, V, Si; Wade et al. (2012)) and orbital parameter constraints from accretion histories (Morbidelli et al. 2012). Current models invoke continuous or multi-stage core formation with later epochs being more oxidized and volatile rich (Wood, 2008; Schönbächler et al. 2010; Rubie et al. 2011). Here we show, using models of core liquid wavespeeds, that a volatile-enriched outermost outer core leads to the observed layering in it, as well as satisfying the relative abundances of W and Mo in the mantle and the volume of material added in late-stage core accretion. Layering can be explained by incomplete mixing of late-added core material. Densities of progressively accreted metal vary, initially mixing the growing core but then stratifying upon it. The topmost outer core's structure is consistent with it being a physical remnant of the Moon-forming impact.

  9. Irradiation-accelerated corrosion of reactor core materials

    International Nuclear Information System (INIS)

    Bartels, David; Was, Gary; Jiao, Zhijie

    2012-09-01

    The combination of high temperature, chemically aggressive coolants, a high radiation flux and mechanical stress poses a major challenge for the life extension of current light water reactors, but also applies to most all other GenIV concepts. Of these four drivers, the combination of radiation and corrosion presents a unique and extremely challenging environment for materials, for which an understanding of the fundamental science is essentially absent. Irradiation can affect corrosion or oxidation in at least three different ways. Radiation interaction with water results in the decomposition of water into radicals and oxidizing species that will increase the electrochemical corrosion potential and lead to greater corrosion rates. Irradiation of the solid surface can produce excited states that can alter corrosion, such as in the case of photo-induced corrosion. Lastly, displacement damage in the solid will result in a high flux of defects to the solid-solution interface that can alter and perhaps, accelerate interface reactions. While there exists reasonable understanding of how corrosion is affected by irradiation of the aqueous environment, there is little understanding of how irradiation affects corrosion through its impact on the solid, whether metal or oxide. The reason is largely due to the difficulty of conducting experiments that can measure this effect separately. We have undertaken a project specifically to separate the several effects of irradiation on the mechanisms of corrosion. We seek to answer the question: How does radiation damage to the solution-oxide couple affect the oxidation process differently from radiation damage to either component alone? The approach taken in this work is to closely compare corrosion accelerated by (1) proton irradiation, (2) electron irradiation, and (3) chemical corrosion potential effects alone, under typical PWR operating conditions at 300 deg. C. Both 316 stainless steel and zirconium are to be studied. The proton

  10. Effect of different composite core materials on fracture resistance of endodontically treated teeth restored with FRC posts

    OpenAIRE

    PANITIWAT, Prapaporn; SALIMEE, Prarom

    2017-01-01

    Abstract Objective This study evaluated the fracture resistance of endodontically treated teeth restored with fiber reinforced composite posts, using three resin composite core build-up materials, (Clearfil Photo Core (CPC), MultiCore Flow (MCF), and LuxaCore Z-Dual (LCZ)), and a nanohybrid composite, (Tetric N-Ceram (TNC)). Material and Methods Forty endodontically treated lower first premolars were restored with quartz fiber posts (D.T. Light-Post) cemented with resin cement (Panavia F2...

  11. Geological storage of carbon dioxide in the coal seams: from material to the reservoir

    International Nuclear Information System (INIS)

    Nikoosokhan, S.

    2012-01-01

    CO 2 emissions into the atmosphere are recognized to have a significant effect on global warming. Geological storage of CO 2 is widely regarded as an essential approach to reduce the impact of such emissions on the environment. Moreover, injecting carbon dioxide in coal bed methane reservoirs facilitates the recovery of the methane naturally present, a process known as enhanced coal bed methane recovery (ECBM). But the swelling of the coal matrix induced by the preferential adsorption by coal of carbon dioxide over the methane in place leads to a closure of the cleat system (a set of small natural fractures) of the reservoir and therefore to a loss of injectivity. This PhD thesis is dedicated to a study of how this injectivity evolves in presence of fluids. We derive two poro-mechanical dual-porosity models for a coal bed reservoir saturated by a pure fluid. The resulting constitutive equations enable to better understand and model the link between the injectivity of a coal seam and the adsorption-induced swelling of coal. For both models, the pore space of the reservoir is considered to be divided into the macroporous cleats and the pores of the coal matrix. The two models differ by how adsorption of fluid is taken into account: the first model is restricted to surface adsorption, while the second model can be applied for adsorption in a medium with a generic pore size distribution and thus in a microporous medium such as coal, in which adsorption mostly occurs by micropore filling. The latter model is calibrated on two coals with different sorption and swelling properties. We then perform simulations at various scales (Representative Elementary Volume, coal sample, coal seam). In particular, we validate our model on experimental data of adsorption-induced variations of permeability of coal. We also perform simulations of seams from which methane would be produced (CBM) or of methane-free seams into which CO 2 would be injected. We study the effect of various

  12. Effect of adhesive resin cements on bond strength of ceramic core materials to dentin.

    Science.gov (United States)

    Gundogdu, M; Aladag, L I

    2018-03-01

    The aim of the present study was to evaluate the effects of self-etch and self-adhesive resin cements on the shear bond strength of ceramic core materials bonded to dentin. Extracted, caries-free, human central maxillary incisor teeth were selected, and the vestibule surfaces were cut flat to obtain dentin surfaces. Ceramic core materials (IPS e.max Press and Prettau Zirconia) were luted to the dentin surfaces using three self-etch adhesive systems (Duo-Link, Panavia F 2.0, and RelyX Ultimate Clicker) and two self-adhesive resin systems (RelyX U200 Automix and Maxcem Elite). A shear bond strength test was performed using a universal testing machine. Failure modes were observed under a stereomicroscope, and bonding interfaces between the adhesive resin cements and the teeth were evaluated with a scanning electron microscope. Data were analyzed with Student's t-test and one-way analysis of variance followed by Tukey's test (α = 0.05). The type of adhesive resin cement significantly affected the shear bond strengths of ceramic core materials bonded to dentin (P materials when the specimens were luted with self-adhesive resin cements (P resin cements exhibited better shear bond strength than the self-adhesive resin cements, except for Panavia cement in the IPS e.max Press group. However, shear bond strengths of the self-adhesive resin cements were dependent on the nature of the ceramic core materials.

  13. Antibacterial properties of amalgam and composite resin materials used as cores under crowns.

    Science.gov (United States)

    Al Ghadban, A; Al Shaarani, F

    2012-06-01

    The Aim of this Study was to compare the bacterial growth in the bulk of both amalgam and fluoridated composite resin materials used as cores under crowns at core's surface (in the superficial area of the bulk) and depth levels. With 24 lower premolars, 12 of them were restored with metal posts and amalgam cores (group 1). The rest were restored with glass Fiber-reinforced Composite (FRC) posts and fluoridated composite resin cores (group 2). All specimens were covered with aluminium crowns cemented with resin cement, and then they were soaked in natural saliva for three months. Excoriations abraded from the superficial and the depth areas of the core materials were cultured under aerobic conditions on blood agar plates. After incubation for 2 days, colonies formed on the plates were identified, and the CFU mg(-1) counts were recorded accordingly. Statistical analysis was performed using an independent sample T test. The mean values of CFU mg(-1) counts in group 2 excoriations (surface 39.75, and depth 9.75) were higher than the group 1 excoriations (surface 1.67, and depth 0.42). This study supports the use of amalgam for building up cores due to its antibacterial properties. Composite resin, however, enhanced sizable bacterial growth despite the presence of fluoride.

  14. Fibre reinforced composite: post and core material in a pediatric patient - an alternative to usual.

    Science.gov (United States)

    Acharya, Sonu; Tandon, Shobha

    2014-11-01

    Fractured teeth are always a challenge to the dentist. The root canal therapy today can retain even very badly broken teeth. One of the most accepted techniques involve restoration of extensively carious or badly fractured teeth by the fabrication of a post and core while utilizing the root canal space for anchorage. So far, the only materials that are available to the dentist for this procedure have been a variety of metallic alloys. These materials are hard and need to be cast precisely so that they can fit the canals. Today materials are available which usually eliminates all the intermediate steps which are done in laboratories and the total control is rendered in the hands of the dentist, to fabricate on the chair, a resilient, aesthetic and bonded post and core. One such material is discussed here in a pediatric permanent anterior tooth.

  15. Relative translucency of six all-ceramic systems. Part I: core materials.

    Science.gov (United States)

    Heffernan, Michael J; Aquilino, Steven A; Diaz-Arnold, Ana M; Haselton, Debra R; Stanford, Clark M; Vargas, Marcos A

    2002-07-01

    All-ceramic restorations have been advocated for superior esthetics. Various materials have been used to improve ceramic core strength, but it is unclear whether they affect the opacity of all-ceramic systems. This study compared the translucency of 6 all-ceramic system core materials at clinically appropriate thicknesses. Disc specimens 13 mm in diameter and 0.49 +/- 0.01 mm in thickness were fabricated from the following materials (n = 5 per group): IPS Empress dentin, IPS Empress 2 dentin, In-Ceram Alumina core, In-Ceram Spinell core, In-Ceram Zirconia core, and Procera AllCeram core. Empress and Empress 2 dentin specimens also were fabricated and tested at a thickness of 0.77 +/- 0.02 mm (the manufacturer's recommended core thickness is 0.8 mm). A high-noble metal-ceramic alloy (Porc. 52 SF) served as the control, and Vitadur Alpha opaque dentin was used as a standard. Sample reflectance (ratio of the intensity of reflected light to that of the incident light) was measured with an integrating sphere attached to a spectrophotometer across the visible spectrum (380 to 700 nm); 0-degree illumination and diffuse viewing geometry were used. Contrast ratios were calculated from the luminous reflectance (Y) of the specimens with a black (Yb) and a white (Yw) backing to give Yb/Yw with CIE illuminant D65 and a 2-degree observer function (0.0 = transparent, 1.0 = opaque). One-way analysis of variance and Tukey's multiple-comparison test were used to analyze the data (P In-Ceram Spinell > Empress, Procera, Empress 2 > In-Ceram Alumina > In-Ceram Zirconia, 52 SF alloy.

  16. CORE

    DEFF Research Database (Denmark)

    Krigslund, Jeppe; Hansen, Jonas; Hundebøll, Martin

    2013-01-01

    State-of-the-art in network coding for wireless, meshed networks typically considers two problems separately. First, the problem of providing reliability for a single session. Second, the problem of opportunistic combination of flows by using minimalistic coding, i.e., by XORing packets from...... different flows. Instead of maintaining these approaches separate, we propose a protocol (CORE) that brings together these coding mechanisms. Our protocol uses random linear network coding (RLNC) for intra- session coding but allows nodes in the network to setup inter- session coding regions where flows...

  17. Nanocrystalline material in toroidal cores for current transformer: analytical study and computational simulations

    Directory of Open Access Journals (Sweden)

    Benedito Antonio Luciano

    2005-12-01

    Full Text Available Based on electrical and magnetic properties, such as saturation magnetization, initial permeability, and coercivity, in this work are presented some considerations about the possibilities of applications of nanocrystalline alloys in toroidal cores for current transformers. It is discussed how the magnetic characteristics of the core material affect the performance of the current transformer. From the magnetic characterization and the computational simulations, using the finite element method (FEM, it has been verified that, at the typical CT operation value of flux density, the nanocrystalline alloys properties reinforce the hypothesis that the use of these materials in measurement CT cores can reduce the ratio and phase errors and can also improve its accuracy class.

  18. Evaluation of Core Loss in Magnetic Materials Employed in Utility Grid AC Filters

    DEFF Research Database (Denmark)

    Beres, Remus Narcis; Wang, Xiongfei; Blaabjerg, Frede

    2016-01-01

    magnetic materials adopted in utility grid ac filters have been investigated and measured for both sinusoidal and rectangular excitation, with and without dc bias condition. The core loss information can ensure cost effective passive filter designs and may avoid trial-error design procedures of the passive......Inductive components play an important role in filtering the switching harmonics related to the pulse width modulation in voltage source converters. Particularly, the filter reactor on the converter side of the filter is subjected to rectangular excitation which may lead to significant losses...... in the core, depending on the magnetic material of choice and current ripple specifications. Additionally, shunt or series reactors that exists in LCL or trap filters and which are subjected to sinusoidal excitations have different specifications and requirements. Therefore, the core losses of different...

  19. Improved characterization of reservoir behavior by integration of reservoir performances data and rock type distributions

    Energy Technology Data Exchange (ETDEWEB)

    Davies, D.K.; Vessell, R.K. [David K. Davies & Associates, Kingwood, TX (United States); Doublet, L.E. [Texas A& M Univ., College Station, TX (United States)] [and others

    1997-08-01

    An integrated geological/petrophysical and reservoir engineering study was performed for a large, mature waterflood project (>250 wells, {approximately}80% water cut) at the North Robertson (Clear Fork) Unit, Gaines County, Texas. The primary goal of the study was to develop an integrated reservoir description for {open_quotes}targeted{close_quotes} (economic) 10-acre (4-hectare) infill drilling and future recovery operations in a low permeability, carbonate (dolomite) reservoir. Integration of the results from geological/petrophysical studies and reservoir performance analyses provide a rapid and effective method for developing a comprehensive reservoir description. This reservoir description can be used for reservoir flow simulation, performance prediction, infill targeting, waterflood management, and for optimizing well developments (patterns, completions, and stimulations). The following analyses were performed as part of this study: (1) Geological/petrophysical analyses: (core and well log data) - {open_quotes}Rock typing{close_quotes} based on qualitative and quantitative visualization of pore-scale features. Reservoir layering based on {open_quotes}rock typing {close_quotes} and hydraulic flow units. Development of a {open_quotes}core-log{close_quotes} model to estimate permeability using porosity and other properties derived from well logs. The core-log model is based on {open_quotes}rock types.{close_quotes} (2) Engineering analyses: (production and injection history, well tests) Material balance decline type curve analyses to estimate total reservoir volume, formation flow characteristics (flow capacity, skin factor, and fracture half-length), and indications of well/boundary interference. Estimated ultimate recovery analyses to yield movable oil (or injectable water) volumes, as well as indications of well and boundary interference.

  20. Natural radionuclides from U-238 and Th-232 series and inorganic chemical characterization of soil profiles and sediment cores of the TaiaÇUpeba Reservoir, SÃO Paulo, Brazil

    International Nuclear Information System (INIS)

    Souza, J.M.; Damatto, S.R.; Surkov, A.M.; Silva, A.R.; Maduar, M.F.; Gonçalves, P.N.; Leonardo, L.

    2017-01-01

    Taiaçupeba reservoir, located in the state of São Paulo, Brazil, belongs to Producer System of Alto Tietê (Sistema Produtor Alto Tietê) and it is responsible for water supply for about 3.1million of people. The water quality of a reservoir is very important, but this is reduced by the increase of environmental degradation of the soil around the reservoir and its different uses. The study of soil profiles and sediment cores is an important tool for understanding the geophysical and geochemical aspects of an aquatic ecosystem. The objective of this work was to present the natural radionuclides 238 U, 226 Ra, 210 Pb, 232 Th, 228 Th, 228 Ra and 40 K activity concentrations and also the inorganic chemical characterization of four soil profiles and four sediment cores collected in the area of influence area of Taiaçupeba reservoir. The analytical techniques, gamma spectrometry and instrumental neutron activation analysis were used in the determination. In the soil profiles the highest activity concentrations were obtained for the radionuclides 40 K and 228 Th and the lowest for 210 Pb; in the sediment cores the highest activity concentrations were obtained for the radionuclide 210 Pb and the lowest for 226 Ra and 228 Ra. For the inorganic chemical characterization the highest values obtained were for Na, As and Sb; in a sediment core a very high concentration was obtained for the element Zn indicating a probable accumulation of this element inside the reservoir; enrichment factor was used to evaluate a possible anthropic contamination in the soil and sediment at the margins of Taiaçupeba reservoir. (author)

  1. Natural radionuclides from U-238 and Th-232 series and inorganic chemical characterization of soil profiles and sediment cores of the TaiaÇUpeba Reservoir, SÃO Paulo, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Souza, J.M.; Damatto, S.R.; Surkov, A.M.; Silva, A.R.; Maduar, M.F.; Gonçalves, P.N., E-mail: jmarques@ipen.br, E-mail: damatto@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil); Leonardo, L. [Centro Universitário São Camilo (Campus Ipiranga), São Paulo, SP (Brazil)

    2017-07-01

    Taiaçupeba reservoir, located in the state of São Paulo, Brazil, belongs to Producer System of Alto Tietê (Sistema Produtor Alto Tietê) and it is responsible for water supply for about 3.1million of people. The water quality of a reservoir is very important, but this is reduced by the increase of environmental degradation of the soil around the reservoir and its different uses. The study of soil profiles and sediment cores is an important tool for understanding the geophysical and geochemical aspects of an aquatic ecosystem. The objective of this work was to present the natural radionuclides {sup 238}U, {sup 226}Ra, {sup 210}Pb, {sup 232}Th, {sup 228}Th,{sup 228}Ra and {sup 40}K activity concentrations and also the inorganic chemical characterization of four soil profiles and four sediment cores collected in the area of influence area of Taiaçupeba reservoir. The analytical techniques, gamma spectrometry and instrumental neutron activation analysis were used in the determination. In the soil profiles the highest activity concentrations were obtained for the radionuclides {sup 40}K and {sup 228}Th and the lowest for {sup 210}Pb; in the sediment cores the highest activity concentrations were obtained for the radionuclide {sup 210}Pb and the lowest for {sup 226}Ra and {sup 228}Ra. For the inorganic chemical characterization the highest values obtained were for Na, As and Sb; in a sediment core a very high concentration was obtained for the element Zn indicating a probable accumulation of this element inside the reservoir; enrichment factor was used to evaluate a possible anthropic contamination in the soil and sediment at the margins of Taiaçupeba reservoir. (author)

  2. Bacterial leakage through temporary fillings in core buildup composite material - an in vitro study.

    Science.gov (United States)

    Rechenberg, Dan-Krister; Schriber, Martina; Attin, Thomas

    2012-08-01

    To evaluate the ability of the provisional filling material Cavit-W alone or in combination with different restorative materials to prevent bacterial leakage through simulated access cavities in a resin buildup material. LuxaCore resin cylinders were subdivided into 4 experimental groups (n = 30), plus a positive (n = 5) and a negative (n = 30) control group. One bore hole was drilled through each cylinder, except those in the negative control group (G1). The holes were filled with Cavit-W (G2), Cavit-W and Ketac-Molar (glassionomer cement, G3), Cavit-W and LuxaCore bonded with LuxaBond (G4), Cavit-W and LuxaCore (G5), or left empty (G6). Specimens were mounted in a two-chamber leakage setup. The upper chamber was inoculated with E. faecalis. An enterococci-selective broth was used in the lower chamber. Leakage was assessed for 60 days and compared using Fisher's exact test (α Cavit-W alone or combined with a glass-ionomer cement did not prevent bacterial leakage through a resin buildup material for two months. In contrast, covering Cavit-W with a bonded resin material resulted in a bacteria-tight seal for two months.

  3. Modeling Overlapping Laminations in Magnetic Core Materials Using 2-D Finite-Element Analysis

    DEFF Research Database (Denmark)

    Jensen, Bogi Bech; Guest, Emerson David; Mecrow, Barrie C.

    2015-01-01

    This paper describes a technique for modeling overlapping laminations in magnetic core materials using two-dimensional finite-element (2-D FE) analysis. The magnetizing characteristic of the overlapping region is captured using a simple 2-D FE model of the periodic overlapping geometry...... and a composite material is created, which has the same magnetization characteristic. The benefit of this technique is that it allows a designer to perform design and optimization of magnetic cores with overlapped laminations using a 2-D FE model rather than a 3-D FE model, which saves modeling and simulation...... time. The modeling technique is verified experimentally by creating a composite material of a lap joint with a 3-mm overlapping region and using it in a 2-D FE model of a ring sample made up of a stack of 20 laminations. The B-H curve of the simulated ring sample is compared with the B-H curve obtained...

  4. Toward "Green" Hybrid Materials: Core-Shell Particles with Enhanced Impact Energy Absorbing Ability.

    Science.gov (United States)

    Arias, Veluska; Odent, Jeremy; Raquez, Jean-Marie; Dubois, Philippe; Odelius, Karin; Albertsson, Ann-Christine

    2016-07-05

    Restrained properties of "green" degradable products drive the creation of materials with innovative structures and retained eco-attributes. Herein, we introduce the creation of impact modifiers in the form of core-shell (CS) particles toward the creation of "green" composite materials. Particles with CS structure constituted of PLA stereocomplex (PLASC) and a rubbery phase of poly(ε-caprolactone- co -d,l-lactide) (P[CL- co -LA]) were successfully achieved by spray droplet atomization. A synergistic association of the soft P[CL- co -LA] and hard PLASC domains in the core-shell structure induced unique thermo-mechanical effects on the PLA-based composites. The core-shell particles enhanced the crystallization of PLA matrices by acting as nucleating agents. The core-shell particles functioned efficiently as impact modifiers with minimal effect on the composites stiffness and strength. These findings provide a new platform for scalable design of polymeric-based structures to be used in the creation of advanced degradable materials.

  5. Effect of Fuel Structure Materials on Radiation Source Term in Reactor Core Meltdown

    International Nuclear Information System (INIS)

    Jeong, Hae Sun; Ha, Kwang Soon

    2014-01-01

    The fission product (Radiation Source) releases from the reactor core into the containment is obligatorily evaluated to guarantee the safety of Nuclear Power Plant (NPP) under the hypothetical accident involving a core meltdown. The initial core inventory is used as a starting point of all radiological consequences and effects on the subsequent results of accident assessment. Hence, a proper evaluation for the inventory can be regarded as one of the most important part over the entire procedure of accident analysis. The inventory of fission products is typically evaluated on the basis of the uranium material (e.g., UO2 and USi2) loaded in nuclear fuel assembly, except for the structure materials such as the end fittings, grids, and some kinds of springs. However, the structure materials are continually activated by the neutrons generated from the nuclear fission, and some nuclides of them (e.g., 14 C and 60 Co) can significantly influence on accident assessment. During the severe core accident, the structure components can be also melted with the melting points of temperature relatively lower than uranium material. A series of the calculation were performed by using ORIGEN-S module in SCALE 6.1 package code system. The total activity in each part of structure materials was specifically analyzed from these calculations. The fission product inventory is generally evaluated based on the uranium materials of fuel only, even though the structure components of the assembly are continually activated by the neutrons generated from the nuclear fission. In this study, the activation calculation of the fuel structure materials was performed for the initial source term assessment in the accident of reactor core meltdown. As a result, the lower end fitting and the upper plenum greatly contribute to the total activity except for the cladding material. The nuclides of 56 Mn, '5 1 Cr, 55 Fe, 58 Co, 54 Mn, and 60 Co are analyzed to mainly effect on the activity. This result

  6. Simulated Seismic Load Tests on Dam Core Material to Scrutinize Pore Water Pressure Development

    Science.gov (United States)

    Umar Farooq, Qazi; Uchimura, Taro

    2010-05-01

    Dam Core is the back bone of the large earthen dam and primarily constructed with fine grained soils. In this research Cyclic tri-axial tests are used to simulate the effect of different earthquake intensities on medium to high confined Fujinomori clay (replicated dam core material). Seismic load intensity is reproduced in the laboratory by applying different cyclic stress amplitudes, while the numbers of cycles (N) were kept constant. Both isotropic and anisotropic conditions are included in the test plan. Key discussions are distresses generated by seismic loading such as pore water pressure (PWP), deformations, possibility of micro cracking, and effective strength reduction. With increase in cyclic stress amplitude, exponential increases in pore pressure (PWP), sudden decrease in mean effective principal stress (P') which ultimately increases overall instability in dam core, large deformations, and generation of micro / macro cracking are primary conclusions.

  7. Physical properties of self-, dual-, and light-cured direct core materials.

    Science.gov (United States)

    Rüttermann, Stefan; Alberts, Ian; Raab, Wolfgang H M; Janda, Ralf R

    2011-08-01

    The objective of this study is to evaluate flexural strength, flexural modulus, compressive strength, curing temperature, curing depth, volumetric shrinkage, water sorption, and hygroscopic expansion of two self-, three dual-, and three light-curing resin-based core materials. Flexural strength and water sorption were measured according to ISO 4049, flexural modulus, compressive strength, curing temperature, and curing depth according to well-proven, literature-known methods, and the volumetric behavior was determined by the Archimedes' principle. ANOVA was calculated to find differences between the materials' properties, and correlation of water sorption and hygroscopic expansion was analysed according to Pearson (p hygroscopic expansion (0.0 ± 0.2 vol.%). Clearfil Photo Core and Encore SuperCure Contrast demonstrated the lowest shrinkage (≈2.1 ± 0.1 vol.%). Water sorption and hygroscopic expansion had a very strong positive correlation. The investigated core materials significantly differed in the tested properties. The performance of the materials depended on their formulation, as well as on the respective curing process.

  8. Effect of an adhesive resin luting agent on the dowel-head retention of three different core materials.

    Science.gov (United States)

    Aksoy, Gokhan; Cotert, H Serdar; Korkut, Levent

    2005-05-01

    A dowel-and-core restoration may fail due to failure at either the dowel-tooth or dowel head-core material interface. Long-term clinical success of a dowel-and-core restoration depends on retention of both the dowel to the tooth and the dowel head to the core material. Thus, strengthening of the dowel head-core interface is important. This study evaluated the retention between a prefabricated dowel and 3 different core materials with or without a dual-polymerized adhesive resin luting agent. Sixty prefabricated dowels (Gold Plated Anchorage Post) were divided into 3 groups (n=20) consisting of 1 of 3 core materials, amalgam (Standalloy F), light-polymerized resin composite (Clearfil Ray), or glass ionomer (Chelon-Silver). Each core group was divided into 2 subgroups (n=10), and a dual-polymerized adhesive resin luting agent (Panavia F) was applied to the dowel heads of 1 of these subgroups before application of the core material. The manufacturing procedure was standardized by using a plastic index (4.5-mm internal diameter and 5-mm height) and a custom-made dowel holder, which held the dowel head. Prepared specimens were stored in water at room temperature for 3 months and then loaded to fracture in a universal testing machine with a crosshead speed of 0.05 mm/min until failure. Bond strengths were recorded (MPa). Data were analyzed with 2-way analysis of variance (ANOVA) in a 2 x 3 factorial randomized design (alpha=.05). Afterward, core material differences were computed with 1-way ANOVA for both of the bonded and nonbonded groups. Post hoc multiple comparisons were made with the Dunnett C multiple range test. Dowel-head retention values (MPa) of the tested core materials (mean +/- SD) from the highest to the lowest were as follows: bonded amalgam core, 296.1 +/- 108; bonded composite core, 284.3 +/- 38.3; nonbonded composite core, 177.0 +/- 53.7; nonbonded amalgam core, 128.5 +/- 35.0; bonded glass-ionomer core (GIC), 128.0 +/- 24.5; nonbonded GIC, 61.8 +/- 13

  9. Reservoir core porosity in the Resende formation using 3D high-resolution X-ray computed microtomography

    International Nuclear Information System (INIS)

    Oliveira, Milena F.S.; Lima, Inaya; Lopes, Ricardo T.; Rocha, Paula Lucia F. da

    2009-01-01

    The storage capacity and production of oil are influenced, among other things, by rocks and fluids characteristics. Porosity is one of the most important characteristics to be analyzed in oil industry, mainly in oil prospection because it represents the direct capacity of storage fluids in the rocks. By definition, porosity is the ratio of pore volume to the total bulk volume of the formation, expressed in percentage, being able to be absolute or effective. The aim of this study was to calculate porosity by 3D High-Resolution X-ray Computed Microtomography using core plugs from Resende Formation which were collected in Porto Real, Rio de Janeiro State. This formation is characterized by sandstones and fine conglomerates with associated fine siliciclastic sediments, and the paleoenviroment is interpreted as a braided fluvial system. For acquisitions data, it was used a 3D high resolution microtomography system which has a microfocus X-ray tube (spot size < 5μm) and a 12-bit cooled X-ray camera (CCD fiber-optically coupled to a scintillator) operated at 100 kV and 100 μA. Twenty-two samples taken at different depths from two boreholes were analyzed. A total of 961 slices were performed with a resolution of 14.9 μm. The results demonstrated that μ-CT is a reliable and effective technique. Through the images and data it was possible to quantify the porosity and to view the size and shape of porous. (author)

  10. Using ParaPost Tenax fiberglass and ParaCore build-up material to restore severely damaged teeth.

    Science.gov (United States)

    Caicedo, Ricardo; Castellon, Paulino

    2005-01-01

    This article describes a technique using ParaPost Tenax Fiber White, ParaPost Cement, and ParaPost ParaCore build-up material to restore a tooth with a significant loss of tooth structure. After successful root canal therapy, the posts were bonded in the canals and the core was built using ParaPost ParaCore build-up material. At that point, the tooth was prepared to receive a conventional porcelain-fused-to-metal crown.

  11. Microwave absorbing materials using Ag-NiZn ferrite core-shell nanopowders as fillers

    International Nuclear Information System (INIS)

    Peng, C.-H.; Wang, H.-W.; Kan, S.-W.; Shen, M.-Z.; Wei, Y.-M.; Chen, S.-Y.

    2004-01-01

    Silver nanoparticles coated with Ni 0.5 Zn 0.5 Fe 2 O 4 spinel ferrites, forming a core-shell structure, were synthesized by utilizing hydrothermal method at different ferrite/silver ratio (ferrite/silver=6/1, 4/1, 2/1, 1/1, 1/6) and introduced into polyurethane matrix to be a microwave absorber. The complex permittivity (ε',ε'') and permeability (μ',μ'') of absorbing composite materials consisted of ferrite/silver core-shell nanopowders and polyurethane were measured in the frequency range of 2-15GHz. The reflection loss and matching frequency were calculated from measured data using theory of the absorbing wall for different ferrite/silver ratios. It was found that the matching frequency for reflection loss exceeded a satisfactory -25dB at 9.0GHz for using NiZn ferrite as a filler shifts to higher frequencies (10.9-13.7GHz) as the ferrite/silver ratio of core-shell nano-filler decreased from 6/1 to 2/1. The present result demonstrates that microwave absorbers using ferrite/silver core-shell filler can be fabricated for the applications over 9GHz, with reflection loss more than-25dB for specific frequencies, by controlling the ferrite/silver ratio of the core-shell nano-fillers in the composites

  12. Highly efficient photocatalytic performance of graphene-ZnO quasi-shell-core composite material.

    Science.gov (United States)

    Bu, Yuyu; Chen, Zhuoyuan; Li, Weibing; Hou, Baorong

    2013-12-11

    In the present paper, the graphene-ZnO composite with quasi-shell-core structure was successfully prepared using a one-step wet chemical method. The photocatalytic Rhodamine B degradation property and the photoelectrochemical performance of the graphene-ZnO quasi-shell-core composite are dependent on the amount of graphene oxide that is added. When the amount of graphene oxide added is 10 mg, the graphene-ZnO quasi-shell-core composite possesses the optimal photocatalytic degradation efficiency and the best photoelectrochemical performance. An efficient interfacial electric field is established on the interface between the graphene and ZnO, which significantly improves the separation efficiency of the photogenerated electron-hole pairs and thus dramatically increases its photoelectrochemical performance. In addition to the excellent photocatalytic and photoelectrochemical properties, the electron migration ability of the grephene-ZnO quasi-shell-core composite is significantly enhanced due to the graphene coating on ZnO surface; therefore, this material has great potential for application as a substrate material to accept electrons in dye solar cell and in narrow bandgap semiconductor quantum dot sensitized solar cells.

  13. Standard Test Method for Water Absorption of Core Materials for Structural Sandwich Constructions

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2001-01-01

    1.1 This test method covers the determination of the relative amount of water absorption by various types of structural core materials when immersed or in a high relative humidity environment. This test method is intended to apply to only structural core materials; honeycomb, foam, and balsa wood. 1.2 The values stated in SI units are to be regarded as the standard. The inch-pound units given may be approximate. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  14. Further work on sodium borates as sacrificial materials for a core-catcher

    International Nuclear Information System (INIS)

    Dalle Donne, M.; Dorner, S.; Roth, A.; Werle, H.

    1982-01-01

    Sodium borates are suitable low melting point sacrificial materials for a core-catcher of a fast reactor. Concept, design and initial development work have been described previously. Here we report on the measurements of density, volumetric thermal expansion coefficients and viscosity of borax and sodium metaborate, pure and with various percentages of dissolved UO 2 . The density of these molten salts was measured with the buoyancy method in the temperature range 850 - 1300 0 C, while the viscosity was measured in the temperature range 700 - 1250 0 C with a Haake viscosity balance. Simulation experiments with low melting point materials were performed to investigate the ratio of the downward to sideward melt velocity. The results of these experiments show that this ratio is equal to 0.34 for a solid to liquid density ratio rho = 1.66. For the real borax core-catcher rho = 4 and this would correspond to a velocity ratio of about one

  15. Luminescent liquid crystalline materials based on palladium(II) imine derivatives containing the 2-phenylpyridine core.

    Science.gov (United States)

    Micutz, Marin; Iliş, Monica; Staicu, Teodora; Dumitraşcu, Florea; Pasuk, Iuliana; Molard, Yann; Roisnel, Thierry; Cîrcu, Viorel

    2014-01-21

    In this work we report our studies concerning the synthesis and characterisation of a series of imine derivatives that incorporate the 2-phenylpyridine (2-ppy) core. These derivatives were used in the cyclometalating reactions of platinum(II) or palladium(II) in order to prepare several complexes with liquid crystalline properties. Depending on the starting materials used as well as the solvents employed, different metal complexes were obtained, some of them showing both liquid crystalline behaviour and luminescence properties at room temperature. It was found that, even if there are two competing coordination sites, the cyclometalation process takes place always at the 2-ppy core with (for Pt) or without (for Pd) the imine bond cleavage. We successfully showed that it is possible to prepare emissive room temperature liquid crystalline materials based on double cyclopalladated heteroleptic complexes by varying the volume fraction of the long flexible alkyl tails on the ancillary benzoylthiourea (BTU) ligands.

  16. Behaviour of LWR core materials under accident conditions. Proceedings of a technical committee meeting

    International Nuclear Information System (INIS)

    1996-12-01

    At the invitation of the Government of the Russian Federation, following a proposal of the International Working Group on Water Reactor Fuel Performance and Technology, the IAEA convened a Technical Committee Meeting on Behaviour of LWR Core Materials Under Accident Conditions from 9 to 13 October 1995 in Dimitrovgrad to analyze and evaluate the behaviour of LWR core materials under accident conditions with special emphasis on severe accidents. In-vessel severe accidents phenomena were considered in detail, but specialized thermal hydraulic aspects as well as ex-vessel phenomena were outside the scope of the meeting. Forty participants representing eight countries attended the meeting. Twenty-three papers were presented and discussed during five sessions. Refs, figs, tabs

  17. Diametral tensile strength of four composite resin core materials with and without centered fiber dowels.

    Science.gov (United States)

    Driessen, Cornel H; Ji, Donatta Y-J; Rizkalla, Amin S; Santos, Gildo C

    2011-01-01

    This study evaluated the diametral tensile strength of composite resin core materials with and without fiber dowels. Eight groups were established (n = 20), four with composite resins and four with fiber dowels. Samples were tested using a universal testing machine and evaluated using scanning electron microscopy. One-way ANOVA and a Tukey B-rank order test (P = 0.05) indicated that the tensile values of two of the four composite resins decreased significantly when their matching fiber dowels were introduced.

  18. Materials considerations for UF6 gas-core reactor. Interim report for preliminary design study

    International Nuclear Information System (INIS)

    Wagner, P.

    1977-04-01

    The limiting materials problem in a high-temperature UF 6 core reactor is the corrosion of the core containment vessel. The UF 6 , the lower fluorides of uranium, and the fluorine that exist at the anticipated reactor operating conditions (1000 K and about one atmosphere UF 6 ) are all corrosive. Because of this, the materials evaluation effort for this reactor design study has concentrated on the identification of a viable system for the containment vessel that meets both the materials and neutronic requirements. A study of the literature has revealed that the most promising corrosion-resistant candidates are Ni or Ni-Al alloys. One of the conclusions of this work is that the containment vessel use a nickel liner or clad since the use of Ni as a structural member is precluded by its relative blackness to thermal neutrons. Estimates of corrosion rates of Ni and Ni-Al alloys, the effects of the pressure and temperature of F 2 on the corrosion rates, calculated equilibrium gas compositions at reactor core operating conditions, suggested methods of fabrication, and recommendations for future research and development are included

  19. The influence of anisotropy on the core structure of Shockley partial dislocations within FCC materials

    Science.gov (United States)

    Szajewski, B. A.; Hunter, A.; Luscher, D. J.; Beyerlein, I. J.

    2018-01-01

    Both theoretical and numerical models of dislocations often necessitate the assumption of elastic isotropy to retain analytical tractability in addition to reducing computational load. As dislocation based models evolve towards physically realistic material descriptions, the assumption of elastic isotropy becomes increasingly worthy of examination. We present an analytical dislocation model for calculating the full dissociated core structure of dislocations within anisotropic face centered cubic (FCC) crystals as a function of the degree of material elastic anisotropy, two misfit energy densities on the γ-surface ({γ }{{isf}}, {γ }{{usf}}) and the remaining elastic constants. Our solution is independent of any additional features of the γ-surface. Towards this pursuit, we first demonstrate that the dependence of the anisotropic elasticity tensor on the orientation of the dislocation line within the FCC crystalline lattice is small and may be reasonably neglected for typical materials. With this approximation, explicit analytic solutions for the anisotropic elasticity tensor {B} for both nominally edge and screw dislocations within an FCC crystalline lattice are devised, and employed towards defining a set of effective isotropic elastic constants which reproduce fully anisotropic results, however do not retain the bulk modulus. Conversely, Hill averaged elastic constants which both retain the bulk modulus and reasonably approximate the dislocation core structure are employed within subsequent numerical calculations. We examine a wide range of materials within this study, and the features of each partial dislocation core are sufficiently localized that application of discrete linear elasticity accurately describes the separation of each partial dislocation core. In addition, the local features (the partial dislocation core distribution) are well described by a Peierls-Nabarro dislocation model. We develop a model for the displacement profile which depends upon

  20. Irradiation experiments on materials for core internals, pressure vessel and fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Tsukada, Takashi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    Materials degradation due to the aging phenomena is one of the key issues for the life assessment and extension of the light water reactors (LWRs). This presentation introduces JAERI`s activities in the field of LWR material researches which utilize the research and testing reactors for irradiation experiments. The activities are including the material studies for the core internals, pressure vessel and fuel cladding. These materials are exposed to the neutron/gamma radiation and high temperature water environments so that it is worth reviewing their degradation phenomena as the continuum. Three topics are presented; For the core internal materials, the irradiation assisted stress corrosion cracking (IASCC) of austenitic stainless steels is the present major concern. At JAERI the effects of alloying elements on IASCC have been investigated through the post-irradiation stress corrosion cracking tests in high-temperature water. The radiation embrittlement of pressure vessel steels is still a significant issue for LWR safety, and at JAERI some factors affecting the embrittlement behavior such as a dose rate have been investigated. Waterside corrosion of Zircaloy fuel cladding is one of the limiting factors in fuel rod performance and an in-situ measurement of the corrosion rate in high-temperature water was performed in JMTR. To improve the reliability of experiments and to extent the applicability of experimental techniques, a mutual utilization of the technical achievements in those irradiation experiments is desired. (author)

  1. Mechanical properties of chemically bonded sand core materials dipped in sol-gel coating impregnated with filter

    DEFF Research Database (Denmark)

    Nwaogu, Ugochukwu Chibuzoh; Tiedje, Niels Skat

    2012-01-01

    -displacement curve from which the mechanical properties of the materials are deduced. The fracture surfaces were examined using a stereomicroscope and a scanning electron microscope. From the results, the strengths of the core materials were slightly reduced by the coating in tensile and flexural modes, while......A novel sol-gel coating impregnated with filter dust was applied on chemically bonded sand core materials by dipping. After curing, the strengths of the core materials were measured under uniaxial loading using a new strength testing machine (STM). The STM presents the loading history as a force...

  2. Core Halogenation as a Construction Principle in Tuning the Material Properties of Tetraazaperopyrenes.

    Science.gov (United States)

    Hahn, Lena; Maass, Friedrich; Bleith, Tim; Zschieschang, Ute; Wadepohl, Hubert; Klauk, Hagen; Tegeder, Petra; Gade, Lutz H

    2015-12-01

    A detailed study on the effects of core halogenation of tetraazaperopyrene (TAPP) derivatives is presented. Its impact on the solid structure, as well as the photophysical and electrochemical properties, has been probed by the means of X-ray crystallography, UV/Vis and fluorescence spectroscopy, high-resolution electron energy loss spectroscopy (HREELS), cyclic voltammetry (CV), and DFT modeling. The aim was to assess the potential of this approach as a construction principle for organic electron-conducting materials of the type studied in this work. Although halogenation leads to a stabilization of the LUMOs compared to the unsubstituted parent compound, the nature of the halide barely affects the LUMO energy while strongly influencing the HOMO energies. In terms of band-gap engineering, it was demonstrated that the HOMO-LUMO gap is decreased by substitution of the TAPP core with halides, the effect being found to be most pronounced for the iodinated derivative. The performance of the recently reported core-fluorinated and core-iodinated TAPP derivatives in organic thin-film transistors (TFTs) was investigated on both a glass substrate, as well as on a flexible plastic substrate (PEN). Field-effect mobilities of up to 0.17 cm(2)  Vs(-1) and on/off current ratio of >10(6) were established. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Analytical methods to characterize heterogeneous raw material for thermal spray process: cored wire Inconel 625

    Science.gov (United States)

    Lindner, T.; Bonebeau, S.; Drehmann, R.; Grund, T.; Pawlowski, L.; Lampke, T.

    2016-03-01

    In wire arc spraying, the raw material needs to exhibit sufficient formability and ductility in order to be processed. By using an electrically conductive, metallic sheath, it is also possible to handle non-conductive and/or brittle materials such as ceramics. In comparison to massive wire, a cored wire has a heterogeneous material distribution. Due to this fact and the complex thermodynamic processes during wire arc spraying, it is very difficult to predict the resulting chemical composition in the coating with sufficient accuracy. An Inconel 625 cored wire was used to investigate this issue. In a comparative study, the analytical results of the raw material were compared to arc sprayed coatings and droplets, which were remelted in an arc furnace under argon atmosphere. Energy-dispersive X-ray spectroscopy (EDX) and X-ray fluorescence (XRF) analysis were used to determine the chemical composition. The phase determination was performed by X-ray diffraction (XRD). The results were related to the manufacturer specifications and evaluated in respect to differences in the chemical composition. The comparison between the feedstock powder, the remelted droplets and the thermally sprayed coatings allows to evaluate the influence of the processing methods on the resulting chemical and phase composition.

  4. Analysis of ringing effects due to magnetic core materials in pulsed nuclear magnetic resonance circuits

    Energy Technology Data Exchange (ETDEWEB)

    Prabhu Gaunkar, N., E-mail: neelampg@iastate.edu; Bouda, N. R. Y.; Nlebedim, I. C.; Hadimani, R. L.; Mina, M.; Jiles, D. C. [Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011 (United States); Bulu, I.; Ganesan, K.; Song, Y. Q. [Schlumberger-Doll Research, Cambridge, Massachusetts 02139 (United States)

    2015-05-07

    This work presents investigations and detailed analysis of ringing in a non-resonant pulsed nuclear magnetic resonance (NMR) circuit. Ringing is a commonly observed phenomenon in high power switching circuits. The oscillations described as ringing impede measurements in pulsed NMR systems. It is therefore desirable that those oscillations decay fast. It is often assumed that one of the causes behind ringing is the role of the magnetic core used in the antenna (acting as an inductive load). We will demonstrate that an LRC subcircuit is also set-up due to the inductive load and needs to be considered due to its parasitic effects. It is observed that the parasitics associated with the inductive load become important at certain frequencies. The output response can be related to the response of an under-damped circuit and to the magnetic core material. This research work demonstrates and discusses ways of controlling ringing by considering interrelationships between different contributing factors.

  5. Shear bond strength of four resin cements used to lute ceramic core material to human dentin.

    Science.gov (United States)

    Altintas, Subutayhan; Eldeniz, Ayçe Unverdi; Usumez, Aslihan

    2008-12-01

    This study evaluated the effect of four resin cements on the shear bond strength of a ceramic core material to dentin. One hundred twenty molar teeth were embedded in a self-curing acrylic resin. The occlusal third of the crowns were sectioned under water cooling. All specimens were randomly divided into four groups of 30 teeth each according to the resin cement used. One hundred twenty cylindrical-shaped, 2.7-mm wide, 3-mm high ceramic core materials were heat-pressed. The core cylinders were then luted with one of the four resin systems to dentin (Super-Bond C&B, Chemiace II, Variolink II, and Panavia F). Half of the specimens (n = 15) were tested after 24 hours; the other half (n = 15) were stored in distilled water at 37 degrees C for 1 day and then thermocycled 1000 times between 5 degrees C and 55 degrees C prior to testing. Shear bond strength of each specimen was measured using a universal testing machine at a crosshead speed of 1 mm/min. The bond strength values were calculated in MPa, and the results were statistically analyzed using a two-way analysis of variance (ANOVA) and Tukey HSD tests. The shear bond strength varied significantly depending on the resin cement used (p 0.05). Significant interactions were present between resin cement and thermocycling (p 0.05). The increase in the shear bond strength values in the Panavia F (4.5 +/- 0.7 MPa) and Variolink II (5.5 +/- 2.1 MPa) groups after thermocycling was also not statistically significant (p > 0.05). Variolink II and Panavia F systems showed higher shear bond strength values than Chemiace II and Super-Bond C&B. They can be recommended for luting ceramic cores to dentin surfaces.

  6. The bond of different post materials to a resin composite cement and a resin composite core material.

    Science.gov (United States)

    Stewardson, D; Shortall, A; Marquis, P

    2012-01-01

    To investigate the bond of endodontic post materials, with and without grit blasting, to a resin composite cement and a core material using push-out bond strength tests. Fiber-reinforced composite (FRC) posts containing carbon (C) or glass (A) fiber and a steel (S) post were cemented into cylinders of polymerized restorative composite without surface treatment (as controls) and after grit blasting for 8, 16, and 32 seconds. Additional steel post samples were sputter-coated with gold before cementation to prevent chemical interaction with the cement. Cylindrical composite cores were bonded to other samples. After sectioning into discs, bond strengths were determined using push-out testing. Profilometry and electron microscopy were used to assess the effect of grit blasting on surface topography. Mean (standard deviation) bond strength values (MPa) for untreated posts to resin cement were 8.41 (2.80) for C, 9.61(1.88) for A, and 19.90 (3.61) for S. Prolonged grit blasting increased bond strength for FRC posts but produced only a minimal increase for S. After 32 seconds, mean values were 20.65 (4.91) for C, 20.41 (2.93) for A, and 22.97 (2.87) for S. Gold-coated steel samples produced the lowest bond strength value, 7.84 (1.40). Mean bond strengths for untreated posts bonded to composite cores were 6.19 (0.95) for C, 13.22 (1.61) for A, and 8.82 (1.18) for S, and after 32 seconds of grit blasting the values were 17.30 (2.02) for C, 26.47 (3.09) for A, and 20.61 (2.67) for S. FRC materials recorded higher roughness values before and after grit blasting than S. With prolonged grit blasting, roughness increased for A and C, but not for S. There was no evidence of significant bonding to untreated FRC posts, but significant bonding occurred between untreated steel posts and the resin cement. Increases in the roughness of FRC samples were material dependent and roughening significantly increased bond strength values (ptested FRC posts is required for effective bonding.

  7. Exploratory study of molten core material/concrete interactions, July 1975--March 1977

    International Nuclear Information System (INIS)

    Powers, D.A.; Dahlgren, D.A.; Muir, J.F.; Murfin, W.D.

    1978-02-01

    An experimental study of the interaction between high-temperature molten materials and structural concrete is described. The experimental efforts focused on the interaction of melts of reactor core materials weighing 12 to 200 kg at temperatures 1700 to 2800 0 C with calcareous and basaltic concrete representative of that found in existing light-water nuclear reactors. Observations concerning the rate and mode of melt penetration into concrete, the nature and generation rate of gases liberated during the interaction, and heat transfer from the melt to the concrete are described. Concrete erosion is shown to be primarily a melting process with little contribution from mechanical spallation. Water and carbon dioxide thermally released from the concrete are extensively reduced to hydrogen and carbon monoxide. Heat transfer from the melt to the concrete is shown to be dependent on gas generation rate and crucible geometry. Interpretation of results from the interaction experiments is supported by separate studies of the thermal decomposition of concretes, response of bulk concrete to intense heat fluxes (28 to 280 W/cm 2 ), and heat transfer from molten materials to decomposing solids. The experimental results are compared to assumptions made in previous analytic studies of core meltdown accidents in light-water nuclear reactors. A preliminary computer code, INTER, which models and extrapolates results of the experimental program is described. The code allows estimation of the effect of physical parameters on the nature of the melt/concrete interaction

  8. Exploratory study of molten core material/concrete interactions, July 1975--March 1977. [BWR; PWR

    Energy Technology Data Exchange (ETDEWEB)

    Powers, D.A.; Dahlgren, D.A.; Muir, J.F.; Murfin, W.D.

    1978-02-01

    An experimental study of the interaction between high-temperature molten materials and structural concrete is described. The experimental efforts focused on the interaction of melts of reactor core materials weighing 12 to 200 kg at temperatures 1700 to 2800/sup 0/C with calcareous and basaltic concrete representative of that found in existing light-water nuclear reactors. Observations concerning the rate and mode of melt penetration into concrete, the nature and generation rate of gases liberated during the interaction, and heat transfer from the melt to the concrete are described. Concrete erosion is shown to be primarily a melting process with little contribution from mechanical spallation. Water and carbon dioxide thermally released from the concrete are extensively reduced to hydrogen and carbon monoxide. Heat transfer from the melt to the concrete is shown to be dependent on gas generation rate and crucible geometry. Interpretation of results from the interaction experiments is supported by separate studies of the thermal decomposition of concretes, response of bulk concrete to intense heat fluxes (28 to 280 W/cm/sup 2/), and heat transfer from molten materials to decomposing solids. The experimental results are compared to assumptions made in previous analytic studies of core meltdown accidents in light-water nuclear reactors. A preliminary computer code, INTER, which models and extrapolates results of the experimental program is described. The code allows estimation of the effect of physical parameters on the nature of the melt/concrete interaction.

  9. Reliability and properties of core materials for all-ceramic dental restorations

    Directory of Open Access Journals (Sweden)

    Seiji Ban

    2008-07-01

    Full Text Available Various core materials have been used as all-ceramic dental restorations. Since many foreign zirconia product systems were introduced to the Japanese dental market in the past few years, the researches and the papers on zirconia for ceramic biomaterials have immediately drawn considerable attention. Recently, most of the manufactures supply zirconia blocks available to multi-unit posterior bridges using CAD/CAM, because zirconia has excellent mechanical properties comparable to metal, due to its microstructures. The properties of conventional zirconia were further improved by the composite in nano-scale such as zirconia/alumina nanocomposite (NANOZR. There are many interesting behaviors such as long-term stability related to low temperature degradation, effect of sandblasting and heat treatment on the microstructure and the strength, bonding to veneering porcelains, bonding to cement, visible light translucency related to esthetic restoration, X-ray opacity, biocompatibility, fracture load of clinical bridge as well as lifetime and clinical survival rates of the restoratives made with zirconia. From the recent material researches on zirconia not only in Japan but also in the world, this review takes into account these interesting properties of zirconia and reliability as core material for all-ceramic dental restorations.

  10. Application of Integrated Reservoir Management and Reservoir Characterization to Optimize Infill Drilling

    Energy Technology Data Exchange (ETDEWEB)

    None

    1998-01-01

    Infill drilling if wells on a uniform spacing without regard to reservoir performance and characterization foes not optimize reservoir development because it fails to account for the complex nature of reservoir heterogeneities present in many low permeability reservoirs, and carbonate reservoirs in particular. New and emerging technologies, such as geostatistical modeling, rigorous decline curve analysis, reservoir rock typing, and special core analysis can be used to develop a 3-D simulation model for prediction of infill locations.

  11. An efficient strategy for designing ambipolar organic semiconductor material: Introducing dehydrogenated phosphorus atoms into pentacene core

    Science.gov (United States)

    Tang, Xiao-Dan

    2017-09-01

    The charge transport properties of phosphapentacene (P-PEN) derivatives were systematically explored by theoretical calculation. The dehydrogenated P-PENs have reasonable frontier molecular orbital energy levels to facilitate both electron and hole injection. The reduced reorganization energies of dehydrogenated P-PENs could be intimately connected to the bonding nature of phosphorus atoms. From the idea of homology modeling, the crystal structure of TIPSE-4P-2p is constructed and fully optimized. Fascinatingly, TIPSE-4P-2p shows the intrinsic property of ambipolar transport in both hopping and band models. Thus, introducing dehydrogenated phosphorus atoms into pentacene core could be an efficient strategy for designing ambipolar material.

  12. Role of core support material in veneer failure of brittle layer structures.

    Science.gov (United States)

    Hermann, Ilja; Bhowmick, Sanjit; Lawn, Brian R

    2007-07-01

    A study is made of veneer failure by cracking in all-ceramic crown-like layer structures. Model trilayers consisting of a 1 mm thick external glass layer (veneer) joined to a 0.5 mm thick inner stiff and hard ceramic support layer (core) by epoxy bonding or by fusion are fabricated for testing. The resulting bilayers are then glued to a thick compliant polycarbonate slab to simulate a dentin base. The specimens are subjected to cyclic contact (occlusal) loading with spherical indenters in an aqueous environment. Video cameras are used to record the fracture evolution in the transparent glass layer in situ during testing. The dominant failure mode is cone cracking in the glass veneer by traditional outer (Hertzian) cone cracks at higher contact loads and by inner (hydraulically pumped) cone cracks at lower loads. Failure is deemed to occur when one of these cracks reaches the veneer/core interface. The advantages and disadvantages of the alumina and zirconia core materials are discussed in terms of mechanical properties-strength and toughness, as well as stiffness. Consideration is also given to the roles of interface strength and residual thermal expansion mismatch stresses in relation to the different joining methods. Copyright 2006 Wiley Periodicals, Inc.

  13. Nonlinear Thermo-mechanical Finite Element Analysis of Polymer Foam Cored Sandwich Structures including Geometrical and Material Nonlinearity

    DEFF Research Database (Denmark)

    Palleti, Hara Naga Krishna Teja; Thomsen, Ole Thybo; Taher, Siavash Talebi

    In this paper, polymer foam cored sandwich structures with fibre reinforced composite face sheets subjected to combined mechanical and thermal loads will be analysed using the commercial FE code ABAQUS® incorporating both material and geometrical nonlinearity. Large displacements and rotations...

  14. Metal (Hydr)oxides@Polymer Core-Shell Strategy to Metal Single-Atom Materials.

    Science.gov (United States)

    Zhang, Maolin; Wang, Yang-Gang; Chen, Wenxing; Dong, Juncai; Zheng, Lirong; Luo, Jun; Wan, Jiawei; Tian, Shubo; Cheong, Weng-Chon; Wang, Dingsheng; Li, Yadong

    2017-08-16

    Preparing metal single-atom materials is currently attracting tremendous attention and remains a significant challenge. Herein, we report a novel core-shell strategy to synthesize single-atom materials. In this strategy, metal hydroxides or oxides are coated with polymers, followed by high-temperature pyrolysis and acid leaching, metal single atoms are anchored on the inner wall of hollow nitrogen-doped carbon (CN) materials. By changing metal precursors or polymers, we demonstrate the successful synthesis of different metal single atoms dispersed on CN materials (SA-M/CN, M = Fe, Co, Ni, Mn, FeCo, FeNi, etc.). Interestingly, the obtained SA-Fe/CN exhibits much higher catalytic activity for hydroxylation of benzene to phenol than Fe nanoparticles/CN (45% vs 5% benzene conversion). First-principle calculations further reveal that the high reactivity originates from the easier formation of activated oxygen species at the single Fe site. Our methodology provides a convenient route to prepare a variety of metal single-atom materials representing a new class of catalysts.

  15. Relative translucency of six all-ceramic systems. Part II: core and veneer materials.

    Science.gov (United States)

    Heffernan, Michael J; Aquilino, Steven A; Diaz-Arnold, Ana M; Haselton, Debra R; Stanford, Clark M; Vargas, Marcos A

    2002-07-01

    STATEMENT OF PROBLEM All-ceramic core materials with various strengthening compositions have a range of translucencies. It is unknown whether translucency differs when all-ceramic materials are fabricated similarly to the clinical restoration with a veneered core material. This study compared the translucency of 6 all-ceramic materials veneered and glazed at clinically appropriate thicknesses. Core specimens (n = 5 per group) of Empress dentin, Empress 2 dentin, In-Ceram Alumina, In-Ceram Spinell, In-Ceram Zirconia, and Procera AllCeram were fabricated as described in Part I of this study and veneered with their corresponding dentin porcelain to a final thickness of 1.47 +/- 0.01 mm. These specimens were compared with veneered Vitadur Alpha opaque dentin (as a standard), a clear glass disc (positive control), and a high-noble metal-ceramic alloy (Porc. 52 SF) veneered with Vitadur Omega dentin (negative control). Specimen reflectance was measured with an integrating sphere attached to a spectrophotometer across the visible spectrum (380 to 700 nm); 0-degree illumination and diffuse viewing geometry were used. Measurements were repeated after a glazing cycle. Contrast ratios were calculated from the luminous reflectance (Y) of the specimens with a black (Yb) and a white backing (Yw) to give Yb/Yw with CIE illuminant D65 and a 2-degree observer function (0.0 = transparent, 1.0 = opaque). One-way analysis of variance and Tukey's multiple-comparison test were used to analyze the data (P<.05). Significant differences in contrast ratios were found among the ceramic systems tested when they were veneered (P<.0001) and after the glazing cycle (P<.0001). Significant changes in contrast ratios (P<.0001) also were identified when the veneered specimens were glazed. Within the limitations of this study, a range of translucency was identified in the veneered all-ceramic systems tested. Such variability may affect their ability to match natural teeth. The glazing cycle resulted

  16. Effect of Three Different Core Materials on Masking Ability of a Zirconia Ceramic

    Directory of Open Access Journals (Sweden)

    Farhad Tabatabaian

    2016-12-01

    Full Text Available Objectives: Masking ability of a restorative material plays a role in hiding colored substructures; however, the masking ability of zirconia ceramic (ZRC has not yet been clearly understood in zirconia-based restorations. This study evaluated the effect of three different core materials on masking ability of a ZRC.Materials and Methods: Ten zirconia disc samples, 0.5mm in thickness and 10mm in diameter, were fabricated. A white (W substrate (control and three substrates of nickel-chromium alloy (NCA, non-precious gold alloy (NPGA, and ZRC were prepared. The zirconia discs were placed on the four types of substrates for spectrophotometry. The L*, a*, and b* values of the specimens were measured by a spectrophotometer and color change (ΔE values were calculated to determine color differences between the test and control groups and were then compared with the perceptual threshold. Randomized block ANOVA and Bonferroni test analyzed the data. A significance level of 0.05 was considered.Results: The mean and standard deviation values of ΔE for NCA, NPGA, and ZRC groups were 10.26±2.43, 9.45±1.74, and 6.70±1.91 units, respectively. Significant differences were found in the ΔE values between ZRC and the other two experimental groups (NCA and NPGA; P<0.0001 and P=0.001, respectively. The ΔE values for the groups were more than the predetermined perceptual threshold.Conclusions: Within the limitations of this study, it was concluded that the tested ZRC could not well mask the examined core materials.Keywords: Color; Spectrophotometry; Visual Perception; Yttria Stabilized Tetragonal Zirconia

  17. Effect of different composite core materials on fracture resistance of endodontically treated teeth restored with FRC posts.

    Science.gov (United States)

    Panitiwat, Prapaporn; Salimee, Prarom

    2017-01-01

    This study evaluated the fracture resistance of endodontically treated teeth restored with fiber reinforced composite posts, using three resin composite core build-up materials, (Clearfil Photo Core (CPC), MultiCore Flow (MCF), and LuxaCore Z-Dual (LCZ)), and a nanohybrid composite, (Tetric N-Ceram (TNC)). Forty endodontically treated lower first premolars were restored with quartz fiber posts (D.T. Light-Post) cemented with resin cement (Panavia F2.0). Samples were randomly divided into four groups (n=10). Each group was built-up with one of the four core materials following its manufacturers' instructions. The teeth were embedded in acrylic resin blocks. Nickel-Chromium crowns were fixed on the specimens with resin cement. The fracture resistance was determined using a universal testing machine with a crosshead speed of 1 mm/min at 1350 to the tooth axis until failure occurred. All core materials used in the study were subjected to test for the flexural modulus according to ISO 4049:2009. One-way ANOVA and Bonferroni multiple comparisons test indicated that the fracture resistance was higher in the groups with CPC and MCF, which presented no statistically significant difference (p>0.05), but was significantly higher than in those with LCZ and TNC (paligned with the same tendency of fracture loads. Among the cores used in this study, the composite core with high filler content tended to enhance fracture thresholds of teeth restored with fiber posts more than others.

  18. Fracture Resistance of Endodontically Treated Teeth Restored with Biodentine, Resin Modified GIC and Hybrid Composite Resin as a Core Material.

    Science.gov (United States)

    Subash, Dayalan; Shoba, Krishnamma; Aman, Shibu; Bharkavi, Srinivasan Kumar Indu; Nimmi, Vijayan; Abhilash, Radhakrishnan

    2017-09-01

    The restoration of a severely damaged tooth usually needs a post and core as a part of treatment procedure to provide a corono - radicular stabilization. Biodentine is a class of dental material which possess high mechanical properties with excellent biocompatibility and bioactive behaviour. The sealing ability coupled with optimum physical properties could make Biodentine an excellent option as a core material. The aim of the study was to determine the fracture resistance of Biodentine as a core material in comparison with resin modified glass ionomer and composite resin. Freshly extracted 30 human permanent maxillary central incisors were selected. After endodontic treatment followed by post space preparation and luting of Glass fibre post (Reforpost, Angelus), the samples were divided in to three groups based on the type of core material. The core build-up used in Group I was Biodentine (Septodont, France), Group II was Resin-Modified Glass Ionomer Cement (GC, Japan) and Group III was Hybrid Composite Resin (TeEconom plus, Ivoclar vivadent). The specimens were subjected to fracture toughness using Universal testing machine (1474, Zwick/Roell, Germany) and results were compared using One-way analysis of variance with Tukey's Post hoc test. The results showed that there was significant difference between groups in terms of fracture load. Also, composite resin exhibited highest mean fracture load (1039.9 N), whereas teeth restored with Biodentine demonstrated the lowest mean fracture load (176.66 N). Resin modified glass ionomer exhibited intermediate fracture load (612.07 N). The primary mode of failure in Group I and Group II was favourable (100%) while unfavourable fracture was seen in Group III (30%). Biodentine, does not satisfy the requirements to be used as an ideal core material. The uses of RMGIC's as a core build-up material should be limited to non-stress bearing areas. Composite resin is still the best core build-up material owing to its high fracture

  19. CO2 Reaction Induced Wettability Alteration and its Impacts on CO2 Storage: Pore to Core Scale Reservoir Condition Experimental Studies

    Science.gov (United States)

    Wan, J.; Tokunaga, T. K.; Kim, Y.; Jung, J.; Kim, T.; Dong, W.

    2013-12-01

    Wettability of the mineral surfaces plays an important role in subsurface multiphase flow and transport. Wettability affects the capillary pressure-saturation (Pc- S) relations, relative permeability (kr) of each fluid phase, and relative phase occupancy in reservoir pores. Although wettability issues have been studied extensively in other fields, significant knowledge gaps remain when applying the existing understanding to geological carbon sequestration; due largely to the unique physical-chemical properties of supercritical (sc) CO2 relative to other common non-wetting fluids such as air and oil. Here, we report our recent progress on wettability alteration upon reaction with CO2 and the resulting differences in capillary trapping of CO2 versus air. (1) Pore Scale Studies. There are conflict predictions in the literature concerning the effect of wettability on capillary trapping; some find that larger contact angles lead to lower capillary trapping while others have found opposite behavior. We hypothesized that spontaneous imbibition becomes energetically unfavorable with decreased wettability, so that increased residual trapping of scCO2 should occur during the post-injection inbibition stage. We developed a laboratory high-pressure and elevated temperature microscopic-micromodel system that is capable of controlling fine scale capillary pressure of scCO2-brine, and enabled us to conduct imbibition under controlled capillary pressures at the pore scale. We found that the de-wetting enhanced scCO2 capillary trapping is significant. These results suggest that scCO2 reaction induced dewetting can result in higher degrees of CO2 residual trapping in the post-injection stage than previously predicted. (2) Core Scale Studies. Capillary scaling is used routinely to predict Pc(S) relations for scCO2-brine systems at field scale, based on relations measured with air-water or mercury porosimetry. However, scaling-based predictions for CO2-brine systems have not been

  20. Dependences of optical properties of spherical two-layered nanoparticles on parameters of gold core and material shell

    International Nuclear Information System (INIS)

    Pustovalov, V.K.; Astafyeva, L.G.; Zharov, V.P.

    2013-01-01

    Modeling of nonlinear dependences of optical properties of spherical two-layered gold core and some material shell nanoparticles (NPs) placed in water on parameters of core and shell was carried out on the basis of the extended Mie theory. Efficiency cross-sections of absorption, scattering and extinction of radiation with wavelength 532 nm by core–shell NPs in the ranges of core radii r 00 =5–40 nm and of relative NP radii r 1 /r 00 =1–8 were calculated (r 1 —radius of two-layered nanoparticle). Shell materials were used with optical indexes in the ranges of refraction n 1 =0.2–1.5 and absorption k 1 =0–3.5 for the presentation of optical properties of wide classes of shell materials (including dielectrics, metals, polymers, vapor shell around gold core). Results show nonlinear dependences of optical properties of two-layered NPs on optical indexes of shell material, core r 00 and relative NP r 1 /r 00 radii. Regions with sharp decrease and increase of absorption, scattering and extinction efficiency cross-sections with changing of core and shell parameters were investigated. These dependences should be taken into account for applications of two-layered NPs in laser nanomedicine and optical diagnostics of tissues. The results can be used for experimental investigation of shell formation on NP core and optical determination of geometrical parameters of core and shell of two-layered NPs. -- Highlights: • Absorption, scattering and extinction of two-layered nanoparticles are studied. • Shell materials change in wide regions of materials (metals, dielectrics, vapor). • Effect of sharp decrease and increase of optical characteristics is established. • Explanation of sharp decreasing and increasing optical characteristics is presented

  1. [Fracture resistance of thin-walled teeth restored with different post and core materials].

    Science.gov (United States)

    Zhou, Wen-mei; Huang, Guo-wei

    2014-06-01

    To discuss the selection of appropriate post and core materials in order to obtain better fracture resistance for thin-walled teeth. Ninety maxillary incisors were endodontically treated and the crowns were cut off. Then they were randomly divided into 9 groups. The teeth in the first 4 groups were restored with cast (A1.3 and A1.6) and fiber (B1.3 and B1.6) posts of 1.3 and 1.7 mm diameters. The teeth in the other 5 groups were enlarged to simulate the 1 mm thin-walled teeth and restored with cast (C) and fiber posts. The fiber posts were reconstructed and cemented with Unicem (D1.3 and D1.6) and ParaCore (E1.3 and E1.6). All teeth were restored with full crown, and the fracture resistance and fracture mode were analysed. Statistical analysis was carried out using SPSS 16.0 software package. Largest fracture resistance values (610.2 ± 45.6) N were found in Group A1.3 of ordinary root canals, and no significant difference (P>0.05) existed between Group A1.3, A1.6 and B1.3, B1.6. Group C received the largest fracture resistance value(584.5 ± 121.2) N in thin-walled root canals, and fiber posts reconstructed with ParaCore cement could increase fracture resistance [E1.3,(420.6 ± 95.7) N; E1.6,(517.9 ± 67.2) N], which was significant different compared with D1.3 and D1.6 (PParacore.

  2. Fabrication of Silicon Nitride Dental Core Ceramics with Borosilicate Veneering material

    International Nuclear Information System (INIS)

    Wananuruksawong, R; Jinawath, S; Wasanapiarnpong, T; Padipatvuthikul, P

    2011-01-01

    Silicon nitride (Si 3 N 4 ) ceramic is a great candidate for clinical applications due to its high fracture toughness, strength, hardness and bio-inertness. This study has focused on the Si 3 N 4 ceramic as a dental core material. The white Si 3 N 4 was prepared by pressureless sintering at relative low sintering temperature of 1650 deg. C in nitrogen atmosphere. The coefficient of thermal expansion (CTE) of Si 3 N 4 ceramic is lower than that of Zirconia and Alumina ceramic which are popular in this field. The borosilicate glass veneering was employed due to its compatibility in thermal expansion. The sintered Si 3 N 4 specimens represented the synthetic dental core were paintbrush coated by a veneer paste composed of borosilicate glass powder ( 2 O 3 - partial stabilized zirconia) and 30 wt% of polyvinyl alcohol (5 wt% solution). After coating the veneer on the Si 3 N 4 specimens, the firing was performed in electric tube furnace between 1000-1200 deg. C. The veneered specimens fired at 1100 deg. C for 15 mins show good bonding, smooth and glossy without defect and crazing. The veneer has thermal expansion coefficient as 3.98x10 -6 deg. C -1 , rather white and semi opaque, due to zirconia addition, the Vickers hardness as 4.0 GPa which is closely to the human teeth.

  3. Fabrication of Silicon Nitride Dental Core Ceramics with Borosilicate Veneering material

    Science.gov (United States)

    Wananuruksawong, R.; Jinawath, S.; Padipatvuthikul, P.; Wasanapiarnpong, T.

    2011-10-01

    Silicon nitride (Si3N4) ceramic is a great candidate for clinical applications due to its high fracture toughness, strength, hardness and bio-inertness. This study has focused on the Si3N4 ceramic as a dental core material. The white Si3N4 was prepared by pressureless sintering at relative low sintering temperature of 1650 °C in nitrogen atmosphere. The coefficient of thermal expansion (CTE) of Si3N4 ceramic is lower than that of Zirconia and Alumina ceramic which are popular in this field. The borosilicate glass veneering was employed due to its compatibility in thermal expansion. The sintered Si3N4 specimens represented the synthetic dental core were paintbrush coated by a veneer paste composed of borosilicate glass powder (<150 micrometer, Pyrex) with 5 wt% of zirconia powder (3 wt% Y2O3 - partial stabilized zirconia) and 30 wt% of polyvinyl alcohol (5 wt% solution). After coating the veneer on the Si3N4 specimens, the firing was performed in electric tube furnace between 1000-1200°C. The veneered specimens fired at 1100°C for 15 mins show good bonding, smooth and glossy without defect and crazing. The veneer has thermal expansion coefficient as 3.98×10-6 °C-1, rather white and semi opaque, due to zirconia addition, the Vickers hardness as 4.0 GPa which is closely to the human teeth.

  4. The CERN antiproton target: hydrocode analysis of its core material dynamic response under proton beam impact

    CERN Document Server

    Martin, Claudio Torregrosa; Calviani, Marco; Muñoz-Cobo, José-Luis

    2016-01-01

    Antiprotons are produced at CERN by colliding a 26 GeV/c proton beam with a fixed target made of a 3 mm diameter, 55 mm length iridium core. The inherent characteristics of antiproton production involve extremely high energy depositions inside the target when impacted by each primary proton beam, making it one of the most dynamically demanding among high energy solid targets in the world, with a rise temperature above 2000 {\\deg}C after each pulse impact and successive dynamic pressure waves of the order of GPa's. An optimized redesign of the current target is foreseen for the next 20 years of operation. As a first step in the design procedure, this numerical study delves into the fundamental phenomena present in the target material core under proton pulse impact and subsequent pressure wave propagation by the use of hydrocodes. Three major phenomena have been identified, (i) the dominance of a high frequency radial wave which produces destructive compressive-to-tensile pressure response (ii) The existence of...

  5. CERN antiproton target: Hydrocode analysis of its core material dynamic response under proton beam impact

    Directory of Open Access Journals (Sweden)

    Claudio Torregrosa Martin

    2016-07-01

    Full Text Available Antiprotons are produced at CERN by colliding a 26  GeV/c proton beam with a fixed target made of a 3 mm diameter, 55 mm length iridium core. The inherent characteristics of antiproton production involve extremely high energy depositions inside the target when impacted by each primary proton beam, making it one of the most dynamically demanding among high energy solid targets in the world, with a rise temperature above 2000 °C after each pulse impact and successive dynamic pressure waves of the order of GPa’s. An optimized redesign of the current target is foreseen for the next 20 years of operation. As a first step in the design procedure, this numerical study delves into the fundamental phenomena present in the target material core under proton pulse impact and subsequent pressure wave propagation by the use of hydrocodes. Three major phenomena have been identified, (i the dominance of a high frequency radial wave which produces destructive compressive-to-tensile pressure response (ii The existence of end-of-pulse tensile waves and its relevance on the overall response (iii A reduction of 44% in tensile pressure could be obtained by the use of a high density tantalum cladding.

  6. Comparative evaluation of shear bond strength of three resin based dual-cure core build-up materials: An In-vitro study

    OpenAIRE

    Jain, Gaurav; Narad, Aditi; Boruah, Lalit C.; Rajkumar, Balakrishnan

    2015-01-01

    Aim: The in-vitro study compared the shear bond strength (SBS) of three recently introduced dual-cure resin based core build-up materials namely ParaCore, FluoroCore, and MultiCore. Materials and Methods: One hundred twenty extracted permanent human mandibular molar teeth were taken and sectioned horizontally beneath the dentinoenamel junction to expose the coronal dentin. The specimens obtained were divided into three main groups based on the materials used and then further divided into ...

  7. Effect of different composite core materials on fracture resistance of endodontically treated teeth restored with FRC posts

    Directory of Open Access Journals (Sweden)

    Prapaporn PANITIWAT

    Full Text Available Abstract Objective This study evaluated the fracture resistance of endodontically treated teeth restored with fiber reinforced composite posts, using three resin composite core build-up materials, (Clearfil Photo Core (CPC, MultiCore Flow (MCF, and LuxaCore Z-Dual (LCZ, and a nanohybrid composite, (Tetric N-Ceram (TNC. Material and Methods Forty endodontically treated lower first premolars were restored with quartz fiber posts (D.T. Light-Post cemented with resin cement (Panavia F2.0. Samples were randomly divided into four groups (n=10. Each group was built-up with one of the four core materials following its manufacturers’ instructions. The teeth were embedded in acrylic resin blocks. Nickel-Chromium crowns were fixed on the specimens with resin cement. The fracture resistance was determined using a universal testing machine with a crosshead speed of 1 mm/min at 1350 to the tooth axis until failure occurred. All core materials used in the study were subjected to test for the flexural modulus according to ISO 4049:2009. Results One-way ANOVA and Bonferroni multiple comparisons test indicated that the fracture resistance was higher in the groups with CPC and MCF, which presented no statistically significant difference (p>0.05, but was significantly higher than in those with LCZ and TNC (p<0.05. In terms of the flexural modulus, the ranking from the highest values of the materials was aligned with the same tendency of fracture loads. Conclusion Among the cores used in this study, the composite core with high filler content tended to enhance fracture thresholds of teeth restored with fiber posts more than others.

  8. Derivation of temperature dependent mechanical properties of polymer foam core materials using optical extensometry

    Directory of Open Access Journals (Sweden)

    Fruehmann R.K.

    2010-06-01

    Full Text Available A methodology for determining the temperature dependence of Young’s modulus and Poisson’s ratio of polymer foams core materials is presented. The design of the test specimen is described in detail, covering the parasitic effects resulting from departures from the uniform strain condition. The measurement approach is based on a non-contact technique so that the behaviour of the complaint foam is not modified by the attachment of strain gauges or extensometers. Firstly experiments are conducted at room temperature and then at elevated temperatures in a thermal chamber. Readings are taken through an optical window using a standard digital camera. Digital image correlation is used to obtain the strains.

  9. Building waste management core indicators through Spatial Material Flow Analysis: Net recovery and transport intensity indexes

    Energy Technology Data Exchange (ETDEWEB)

    Font Vivanco, David, E-mail: font@cml.leidenuniv.nl [Institut de Ciencia i Tecnologia Ambientals (ICTA), Departament d' Enginyeria Quimica, Universitat Autonoma de Barcelona (UAB), 08193 Bellaterra, Barcelona (Spain); Institute of Environmental Sciences (CML), Leiden University, P.O. Box 9518, 2300 RA Leiden (Netherlands); Puig Ventosa, Ignasi [ENT Environment and Management, Carrer Sant Joan 39, First Floor, 08800 Vilanova i la Geltru, Barcelona (Spain); Gabarrell Durany, Xavier [Institut de Ciencia i Tecnologia Ambientals (ICTA), Departament d' Enginyeria Quimica, Universitat Autonoma de Barcelona (UAB), 08193 Bellaterra, Barcelona (Spain)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Sustainability and proximity principles have a key role in waste management. Black-Right-Pointing-Pointer Core indicators are needed in order to quantify and evaluate them. Black-Right-Pointing-Pointer A systematic, step-by-step approach is developed in this study for their development. Black-Right-Pointing-Pointer Transport may play a significant role in terms of environmental and economic costs. Black-Right-Pointing-Pointer Policy action is required in order to advance in the consecution of these principles. - Abstract: In this paper, the material and spatial characterization of the flows within a municipal solid waste (MSW) management system are combined through a Network-Based Spatial Material Flow Analysis. Using this information, two core indicators are developed for the bio-waste fraction, the Net Recovery Index (NRI) and the Transport Intensity Index (TII), which are aimed at assessing progress towards policy-related sustainable MSW management strategies and objectives. The NRI approaches the capacity of a MSW management system for converting waste into resources through a systematic metabolic approach, whereas the TII addresses efficiency in terms of the transport requirements to manage a specific waste flow throughout the entire MSW management life cycle. Therefore, both indicators could be useful in assessing key MSW management policy strategies, such as the consecution of higher recycling levels (sustainability principle) or the minimization of transport by locating treatment facilities closer to generation sources (proximity principle). To apply this methodological approach, the bio-waste management system of the region of Catalonia (Spain) has been chosen as a case study. Results show the adequacy of both indicators for identifying those points within the system with higher capacity to compromise its environmental, economic and social performance and therefore establishing clear targets for policy

  10. Building waste management core indicators through Spatial Material Flow Analysis: Net recovery and transport intensity indexes

    International Nuclear Information System (INIS)

    Font Vivanco, David; Puig Ventosa, Ignasi; Gabarrell Durany, Xavier

    2012-01-01

    Highlights: ► Sustainability and proximity principles have a key role in waste management. ► Core indicators are needed in order to quantify and evaluate them. ► A systematic, step-by-step approach is developed in this study for their development. ► Transport may play a significant role in terms of environmental and economic costs. ► Policy action is required in order to advance in the consecution of these principles. - Abstract: In this paper, the material and spatial characterization of the flows within a municipal solid waste (MSW) management system are combined through a Network-Based Spatial Material Flow Analysis. Using this information, two core indicators are developed for the bio-waste fraction, the Net Recovery Index (NRI) and the Transport Intensity Index (TII), which are aimed at assessing progress towards policy-related sustainable MSW management strategies and objectives. The NRI approaches the capacity of a MSW management system for converting waste into resources through a systematic metabolic approach, whereas the TII addresses efficiency in terms of the transport requirements to manage a specific waste flow throughout the entire MSW management life cycle. Therefore, both indicators could be useful in assessing key MSW management policy strategies, such as the consecution of higher recycling levels (sustainability principle) or the minimization of transport by locating treatment facilities closer to generation sources (proximity principle). To apply this methodological approach, the bio-waste management system of the region of Catalonia (Spain) has been chosen as a case study. Results show the adequacy of both indicators for identifying those points within the system with higher capacity to compromise its environmental, economic and social performance and therefore establishing clear targets for policy prioritization. Moreover, this methodological approach permits scenario building, which could be useful in assessing the outcomes of

  11. The effects of post-core and crown material and luting agents on stress distribution in tooth restorations.

    Science.gov (United States)

    Oyar, Perihan

    2014-08-01

    Cement microfracture, post-and-core dislodgement, and tooth fracture are related to the mechanical properties and deformation of restorations. The purpose of this study was to determine which combinations of post-and-core cements provide the most favorable stress distribution upon loading. Three-dimensional models of teeth were created with the ANSYS program to simulate the different materials used for metal ceramic crowns (nickel-chromium, gold-palladium), posts and cores (Ti, Ni-Cr, Au-Pd), and cement (glass ionomer, composite resin, zinc phosphate, polycarboxylate, Panavia). Models were divided into 2 groups according to the alloys used in the crown restorations. A simulated masticatory force of 400 N was applied to the occlusal surface at a 45-degree inclination in the linguolabial direction to the long axis of the tooth, and von Mises equivalent stress values were calculated. The Ni-Cr metal ceramic crown/Au-Pd post-and-core/glass ionomer cement had the highest residual root von Mises equivalent stress value, whereas the Ni-Cr metal ceramic crown/Ni-Cr post-and-core/glass ionomer cement had the highest post stress value and the Ni-Cr metal ceramic crown/Au-Pd post-and-core/zinc phosphate cement had the highest cement stress value. For each post-and-core alloy, the stress values in the post and core were higher with Au-Pd metal ceramic crowns than with Ni-Cr metal ceramic crowns. The post-and-core material affected the amount of deformation. The use of a post-and-core material with a lower elastic modulus and a cement with a higher elastic modulus led to a reduction in deformation in the residual root, cement, and post and core, and a reduction in stress in the post and core. The Ni-Cr metal ceramic crown/Au-Pd post-and-core/zinc phosphate cement or Panavia may therefore be favorable for post-and-core restorations. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  12. Numerical simulation of the insulation material transport to a PWR core under loss of coolant accident conditions

    International Nuclear Information System (INIS)

    Höhne, Thomas; Grahn, Alexander; Kliem, Sören; Rohde, Ulrich; Weiss, Frank-Peter

    2013-01-01

    Highlights: ► Detailed results of a numerical simulation of the insulation material transport to a PWR core are shown. ► The spacer grid is modeled as a strainer which completely retains the insulation material carried by coolant. ► The CFD calculations showed that the fibers at the upper spacer grid plane are not uniformly distributed. ► Furthermore the pressure loss does not exceed a critical limit. ► The PWR core coolablity can be guaranteed all the time during the transient. -- Abstract: In 1992, strainers on the suction side of the ECCS pumps in Barsebäck NPP Unit 2 became partially clogged with mineral wool because after a safety valve opened the steam impinged on thermally insulated equipment and released mineral wool. This event pointed out that strainer clogging is an issue in the course of a loss-of-coolant accident. Modifications of the insulation material, the strainer area and mesh size were carried out in most of the German NPPs. Moreover, back flushing procedures to remove the mineral wool from the strainers and differential pressure measurements were implemented to assure the performance of emergency core cooling during the containment sump recirculation mode. Nevertheless, it cannot be completely ruled out, that a limited amount of small fractions of the insulation material is transported into the RPV. During a postulated cold leg LOCA with hot leg ECC injection, the fibers enter the upper plenum and can accumulate at the fuel element spacer grids, preferably at the uppermost grid level. This effect might affect the ECC flow into the core and could result in degradation of core cooling. It was the aim of the numerical simulations presented to study where and how many mineral wool fibers are deposited at the upper spacer grid. The 3D, time dependent, multi-phase flow problem was modeled applying the CFD code ANSYS CFX. The CFD calculation does not yet include steam production in the core and also does not include re-suspension of the

  13. [Research on bond durability among different core materials and zirconia ceramic cemented by self-adhesive resin cements].

    Science.gov (United States)

    Xinyu, Luo; Xiangfeng, Meng

    2017-02-01

    This research estimated shear bond durability of zirconia and different substrates cemented by two self-adhesive resin cements (Clearfil SA Luting and RelyX U100) before and after aging conditioning. Machined zirconia ceramic discs were cemented with four kinds of core material (cobalt-chromium alloy, flowable composite resin core material, packable composite resin, and dentin) with two self-adhesive resin cements (Clearfil SA Luting and RelyX U100). All specimens were divided into eight test groups, and each test group was divided into two subgroups. Each subgroup was subjected to shear test before and after 10 000 thermal cycles. All factors (core materials, cements, and thermal cycle) significantly influenced bond durability of zirconia ceramic (P0.05); observed shear bond strength was significantly higher than those of other substrates (Presin core material, and packable composite resin than that of RelyX U100 (P0.05). Different core materials and self-adhesive resin cements can significantly affect bond durability of zirconia ceramic. 
.

  14. Interfacial characterization of ceramic core materials with veneering porcelain for all-ceramic bi-layered restorative systems.

    Science.gov (United States)

    Tagmatarchis, Alexander; Tripodakis, Aris-Petros; Filippatos, Gerasimos; Zinelis, Spiros; Eliades, George

    2014-01-01

    The aim of the study was to characterize the elemental distribution at the interface between all-ceramic core and veneering porcelain materials. Three groups of all-ceramic cores were selected: A) Glass-ceramics (Cergo, IPS Empress, IPS Empress 2, e-max Press, Finesse); B) Glass-infiltrated ceramics (Celay Alumina, Celay Zirconia) and C) Densely sintered ceramics (Cercon, Procera Alumina, ZirCAD, Noritake Zirconia). The cores were combined with compatible veneering porcelains and three flat square test specimens were produced for each system. The core-veneer interfaces were examined by scanning electron microscopy and energy dispersive x-ray microanalysis. The glass-ceramic systems showed interfacial zones reach in Si and O, with the presence of K, Ca, Al in core and Ca, Ce, Na, Mg or Al in veneer material, depending on the system tested. IPS Empress and IPS Empress 2 demonstrated distinct transitional phases at the core-veneer interface. In the glassinfiltrated systems, intermixing of core (Ce, La) with veneer (Na, Si) elements occurred, whereas an abrupt drop of the core-veneer elemental concentration was documented at the interfaces of all densely sintered ceramics. The results of the study provided no evidence of elemental interdiffusion at the core-veneer interfaces in densely sintered ceramics, which implies lack of primary chemical bonding. For the glass-containing systems (glassceramics and glass-infiltrated ceramics) interdiffusion of the glass-phase seems to play a critical role in establishing a primary bonding condition between ceramic core and veneering porcelain.

  15. Building waste management core indicators through Spatial Material Flow Analysis: net recovery and transport intensity indexes.

    Science.gov (United States)

    Font Vivanco, David; Puig Ventosa, Ignasi; Gabarrell Durany, Xavier

    2012-12-01

    In this paper, the material and spatial characterization of the flows within a municipal solid waste (MSW) management system are combined through a Network-Based Spatial Material Flow Analysis. Using this information, two core indicators are developed for the bio-waste fraction, the Net Recovery Index (NRI) and the Transport Intensity Index (TII), which are aimed at assessing progress towards policy-related sustainable MSW management strategies and objectives. The NRI approaches the capacity of a MSW management system for converting waste into resources through a systematic metabolic approach, whereas the TII addresses efficiency in terms of the transport requirements to manage a specific waste flow throughout the entire MSW management life cycle. Therefore, both indicators could be useful in assessing key MSW management policy strategies, such as the consecution of higher recycling levels (sustainability principle) or the minimization of transport by locating treatment facilities closer to generation sources (proximity principle). To apply this methodological approach, the bio-waste management system of the region of Catalonia (Spain) has been chosen as a case study. Results show the adequacy of both indicators for identifying those points within the system with higher capacity to compromise its environmental, economic and social performance and therefore establishing clear targets for policy prioritization. Moreover, this methodological approach permits scenario building, which could be useful in assessing the outcomes of hypothetical scenarios, thus proving its adequacy for strategic planning. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Chemical and physical analysis of core materials for advanced high temperature reactors with process heat applications

    International Nuclear Information System (INIS)

    Nickel, H.

    1985-08-01

    Various chemical and physical methods for the analysis of structural materials have been developed in the research programmes for advanced high temperature reactors. These methods are discussed using as examples the structural materials of the reactor core - the fuel elements consisting of coated particles in a graphite matrix and the structural graphite. Emphasis is given to the methods of chemical analysis. The composition of fuel kernels is investigated using chemical analysis methods to determine the heavy metals content (uranium, plutonium, thorium and metallic impurity elements) and the amount of non-metallic constituents. The properties of the pyrocarbon and silicon carbide coatings of fuel elements are investigated using specially developed physiochemical methods. Regarding the irradiation behaviour of coated particles and fuel elements, methods have been developed for examining specimens in hot cells following exposures under reactor operating conditions, to supplement the measurements of in-reactor performance. For the structural graphite, the determination of impurities is important because certain impurities may cause pitting corrosion during irradiation. The localized analysis of very low impurity concentrations is carried out using spectrochemical d.c. arc excitation, local laser and inductively coupled plasma methods. (orig.)

  17. Novel dendritic light-emitting materials containing polyhedral oligomeric silsesquioxanes core

    International Nuclear Information System (INIS)

    Chen, K.-B.; Chang, Y.-P.; Yang, S.-H.; Hsu, C.-S.

    2006-01-01

    A new series of star-like light-emitting materials (POSS1, POSS2 and POSS3) were synthesized by hydrosilylation of the polyhedral oligomeric silsesquioxane with 4,4'-bis(4-(di-(4-methylphenyl)amino)styryl)-2-(hexan-1-yloxy) -5-(10-undecen-1-yloxy)benzene (C1), 4,4'-bis[(E)-2-(N-ethylcarbazoyl)ethenyl]-2-(hexan-1-yloxy)-5- (10-undecen-1-yoxy)benzene (C2), and Iridium(III) bis(2-phenylpyridine-C 2 -N') (13-teradecenyl acetonate) (C3), respectively. All synthesized materials are soluble in common organic solvents, such as chloroform, toluene and 1,2-dichloroethane, and exhibit good film-forming properties. Therefore, they can be used to fabricate devices by spin-coating. The aggregation of peripheral chromophores can be prevented by the rigid POSS core. A double-layer, light-emitting diode with the configuration of indium-tin oxide/poly(ethylene 3,4-dioxythiophene)/POSS1/Ca/Al was fabricated using POSS1 as the active layer. The device emitted green light with a maximum brightness of 115 cd/m 2 and a current yield of 0.07 cd/A. When the light-emitting layer is blended with 0.8% electron-transport material, 2-(4'-tert-butylphenyl)-5-(4'-diphenyl)-1,3,4-oxadiazole, the maximum brightness and current yield of the device can reach 1469 cd/m 2 and 0.8 cd/A, respectively. The performance of a POSS2 device with the same device structure can reach 1102 cd/m 2 and 0.88 cd/A. POSS3 is a kind of triplet material and blended with 4,4-N,N'-dicarbazole-biphenyl as host material, to fabricate the light-emitting device. The maximum brightness and current yield reach 1008 cd/m 2 and 1.04 cd/A, respectively. Blending with 1,3,5-tris(2-N-phenylbenzimi dazolyl)benzene as the hole-blocking material yields a maximum brightness and current yield of 1172 cd/m 2 and 3.99 cd/A

  18. Permeability analysis of Asbuton material used as core layers of water resistance in the body of dam

    Science.gov (United States)

    Rahim, H.; Tjaronge, M. W.; Thaha, A.; Djamaluddin, R.

    2017-11-01

    In order to increase consumption of the local materials and national products, large reserves of Asbuton material about 662.960 million tons in the Buton Islands became an alternative as a waterproof core layer in the body of dam. The Asbuton material was used in this research is Lawele Granular Asphalt (LGA). This study was an experimental study conducted in the laboratory by conducting density testing (content weight) and permeability on Asbuton material. Testing of the Asbuton material used Falling Head method to find out the permeability value of Asbuton material. The data of test result to be analyzed are the relation between compaction energy and density value also relation between density value and permeability value of Asbuton material. The result shows that increases the number of blow apply to the Asbuton material at each layer will increase the density of the Asbuton material. The density value of Asbuton material that satisfies the requirements for use as an impermeable core layer in the dam body is 1.53 grams/cm3. The increase the density value (the weight of the contents) of the Asbuton material will reduce its permeability value of the Asbuton material.

  19. Fabrication of Silicon Nitride Dental Core Ceramics with Borosilicate Veneering material

    Energy Technology Data Exchange (ETDEWEB)

    Wananuruksawong, R; Jinawath, S; Wasanapiarnpong, T [Research Unit of Advanced Ceramic, Department of Materials Science, Faculty of Science, Chulalongkorn University, Bangkok (Thailand); Padipatvuthikul, P, E-mail: raayaa_chula@hotmail.com [Faculty of Dentistry, Srinakharinwirot University, Bangkok (Thailand)

    2011-10-29

    Silicon nitride (Si{sub 3}N{sub 4}) ceramic is a great candidate for clinical applications due to its high fracture toughness, strength, hardness and bio-inertness. This study has focused on the Si{sub 3}N{sub 4} ceramic as a dental core material. The white Si{sub 3}N{sub 4} was prepared by pressureless sintering at relative low sintering temperature of 1650 deg. C in nitrogen atmosphere. The coefficient of thermal expansion (CTE) of Si{sub 3}N{sub 4} ceramic is lower than that of Zirconia and Alumina ceramic which are popular in this field. The borosilicate glass veneering was employed due to its compatibility in thermal expansion. The sintered Si{sub 3}N{sub 4} specimens represented the synthetic dental core were paintbrush coated by a veneer paste composed of borosilicate glass powder (<150 micrometer, Pyrex) with 5 wt% of zirconia powder (3 wt% Y{sub 2}O{sub 3} - partial stabilized zirconia) and 30 wt% of polyvinyl alcohol (5 wt% solution). After coating the veneer on the Si{sub 3}N{sub 4} specimens, the firing was performed in electric tube furnace between 1000-1200 deg. C. The veneered specimens fired at 1100 deg. C for 15 mins show good bonding, smooth and glossy without defect and crazing. The veneer has thermal expansion coefficient as 3.98x10{sup -6} deg. C{sup -1}, rather white and semi opaque, due to zirconia addition, the Vickers hardness as 4.0 GPa which is closely to the human teeth.

  20. Reservoir management

    International Nuclear Information System (INIS)

    Satter, A.; Varnon, J.E.; Hoang, M.T.

    1992-01-01

    A reservoir's life begins with exploration leading to discovery followed by delineation of the reservoir, development of the field, production by primary, secondary and tertiary means, and finally to abandonment. Sound reservoir management is the key to maximizing economic operation of the reservoir throughout its entire life. Technological advances and rapidly increasing computer power are providing tools to better manage reservoirs and are increasing the gap between good and neutral reservoir management. The modern reservoir management process involves goal setting, planning, implementing, monitoring, evaluating, and revising plans. Setting a reservoir management strategy requires knowledge of the reservoir, availability of technology, and knowledge of the business, political, and environmental climate. Formulating a comprehensive management plan involves depletion and development strategies, data acquisition and analyses, geological and numerical model studies, production and reserves forecasts, facilities requirements, economic optimization, and management approval. This paper provides management, engineers geologists, geophysicists, and field operations staff with a better understanding of the practical approach to reservoir management using a multidisciplinary, integrated team approach

  1. New evidences for core processing of non-flint, lithic materials in the Late Palaeolithic and Mesolithic of Poland

    Directory of Open Access Journals (Sweden)

    Grzegorz Osipowicz

    2014-03-01

    Full Text Available In the Late Palaeolithic and Mesolithic core processing in Poland was dominated by flint raw materials. The present paper considers the occurrence of non-flint assemblages at the sites Lubrza and Ludowice (Polish Lowland. The focus is on recognition of petrographic studies, technology, typology and use-wear of inventories from both sites. The collections contain debitage, cores and different kinds of tools. As a result the identification of granite, sandstone, quartzite, gneisses, mudstones, slates and single minerals of quartzes and feldspars was established. The use-wear analysis brought good results only in case in porphyry artefacts. The described analyses are accompanied by a review of European non-flint assemblages from Late Palaeolithic and Mesolithic sites and discussion of the role of this type of raw material in core processing.

  2. Constraints from material properties on the dynamics and evolution of Earth's core

    OpenAIRE

    Davies, C.; Pozzo, M.; Gubbins, D.; Alfe, D.

    2015-01-01

    The Earth's magnetic field is powered by energy supplied by the slow cooling and freezing of the liquid iron core. Efforts to determine the thermal and chemical history of the core have been hindered by poor knowledge of the properties of liquid iron alloys at the extreme pressures and temperatures that exist in the core. This obstacle is now being overcome by high-pressure experiments and advanced mineral physics computations. Using these approaches, updated transport properties for Fe-Si-O ...

  3. Material dimensionality effects on the nanoindentation behavior of Al/a-Si core-shell nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, Robert A. [Department of Mechanical Engineering, University of Arkansas, Fayetteville, AR 72701 (United States); Center for Advanced Surface Engineering, University of Arkansas, Fayetteville, AR 72701 (United States); Goss, Josue A. [Center for Advanced Surface Engineering, University of Arkansas, Fayetteville, AR 72701 (United States); Zou, Min, E-mail: mzou@uark.edu [Department of Mechanical Engineering, University of Arkansas, Fayetteville, AR 72701 (United States); Center for Advanced Surface Engineering, University of Arkansas, Fayetteville, AR 72701 (United States)

    2017-08-01

    Highlights: • Nanoindentation behavior of Al/a-Si core-shell nanostructures were studied. • 3D core confinement enables significant deformation recovery beyond elastic limit. • As the confinement is reduced, the deformation recovery is reduced or suppressed. • Atomistic simulations suggest core confinement affects dislocation dynamics. • 3D confinement has the highest percentage of dislocation removal after unloading. - Abstract: The nanoindentation behavior of hemispherical Al/a-Si core-shell nanostructures (CSNs), horizontally-aligned Al/a-Si core-shell nanorods (CSRs) with various lengths, and an Al/a-Si layered thin film has been studied to understand the effects of geometrical confinement of the Al core on the CSN deformation behavior. When loaded beyond the elastic limit, the CSNs have an unconventional load-displacement behavior with no residual displacement after unloading, resulting in no net shape change after indentation. This behavior is enabled by dislocation activities within the confined Al core, as indicated by discontinuous indentation signatures (load-drops and load-jumps) observed in the load-displacement data. When the geometrical confinement of the core is slightly reduced, as in the case of CSRs with the shortest rod length, the discontinuous indentation signatures and deformation resistance are heavily reduced. Further decreases in core confinement result in conventional nanoindentation behavior, regardless of geometry. Supporting molecular dynamics simulations show that dislocations nucleated in the core of a CSN are more effectively removed during unloading compared to CSRs, which supports the hypothesis that the unique deformation resistance of Al/a-Si CSNs are enabled by 3-dimensional confinement of the Al core.

  4. Synthesis of 3D Printable Cu-Ag Core-Shell Materials: Kinetics of CuO Film Removal

    Science.gov (United States)

    Hong, Seongik; Kim, Namsoo

    2015-03-01

    In this research, Cu-Ag core-shell particles were synthesized as a functional and 3D printable material. Using the solid-liquid method, Cu-Ag core-shell particles were simply synthesized, and different particle sizes of 100 nm and 2 μm were used to confirm the size effect in the synthesis and reaction control of the Cu-Ag core-shell particles. In addition, highly viscous Cu-Ag core-shell particle paste was also prepared, and its electrical conductivity was measured. As a result, the reaction rate in the case of the 2 μm Cu particles was controlled by film diffusion, whereas for the 100 nm Cu particles, the reaction rate was controlled by CuO film produced before reacting with Ag ions in solution, and limited by chemical reaction control. Through the solid-liquid method, dendrite-shaped Cu-Ag core-shell particles were formed. Also, the electrical conductivity increased with increasing sintering temperature and core-shell particle concentration.

  5. Material properties of oxide dispersion strengthened (ODS) ferritic steels for core materials of FBR. Tensile properties of sodium exposed and nickel diffused materials

    International Nuclear Information System (INIS)

    Kato, Shoichi; Yoshida, Eiichi

    2002-12-01

    An oxide dispersion strengthened (ODS) ferritic steel is candidate for a long-life core materials of future FBR, because of good swelling resistance and high creep strength. In this study, tensile tests were carried out the long-term extrapolation of sodium environmental effects on the mechanical properties of ODS steels. The tested heats of materials are M93, M11 and F95. The specimens were pre-exposed to sodium for 1,000 and 3,000 hours under non-stress conditions. The pre-exposure to sodium was conducted using a sodium test loop constituted by austenitic steels. For the conditions of sodium exposure test, the sodium temperature was 650 and 700degC, the oxygen concentration in sodium was about 1 ppm and sodium flow rate on the surface of specimen was less than 1x10 -4 m/seconds (nearly static). Further the specimen with the nickel diffused was prepared, which is simulate to nickel diffusing through sodium from the surface of structural stainless steels. The main results obtained were as follows; (1) The tensile strength and the fracture elongation after sodium exposure (maximum 3,000 hours) were same as that of as-received materials. If was considered that the sodium environmental effect is negligible under the condition of this study. (2) Tensile properties of nickel diffused specimens were slightly lower than that of the as-received specimens, but it remains equal to that of thermal aging specimens. (3) The change in microstructure such as a degraded layer was observed on the surface of nickel diffused specimen. In the region of the degraded layer, phase transformations from the α-phase to the γ-phase were recognized. But, the microscopic oxide particles were observed same as that of α-phase base metal. (author)

  6. Crust behavior and erosion rate prediction of EPR sacrificial material impinged by core melt jet

    Energy Technology Data Exchange (ETDEWEB)

    Li, Gen; Liu, Ming, E-mail: ming.liu@mail.xjtu.edu.cn; Wang, Jinshi; Chong, Daotong; Yan, Junjie

    2017-04-01

    Highlights: • A numerical code was developed to analyze melt jet-concrete interaction in the frame of MPS method. • Crust and ablated concrete layer at UO{sub 2}-ZrO{sub 2} melt and concrete interface periodically developed and collapsed. • Concrete surface temperature fluctuated around a low temperature and ablation temperature. • Concrete erosion by Fe-Zr melt jet was significantly faster than that by UO{sub 2}-ZrO{sub 2} melt jet. - Abstract: Sacrificial material is a special ferro-siliceous concrete, designed in the ex-vessel core melt stabilization system of European Pressurized water Reactor (EPR). Given a localized break of RPV lower head, the melt directly impinges onto the dry concrete in form of compact jet. The concrete erosion behavior influences the failure of melt plug, and further affects melt spreading. In this study, a numerical code was developed in the frame of Moving Particle Semi-implicit (MPS) method, to analyze the crust behavior and erosion rate of sacrificial concrete, impinged by prototypic melt jet. In validation of numerical modeling, the time-dependent erosion depth and erosion configuration matched well with the experimental data. Sensitivity study of sacrificial concrete erosion indicates that the crust and ablated concrete layer presented at UO{sub 2}-ZrO{sub 2} melt and concrete interface, whereas no crust could be found in the interaction of Fe-Zr melt with concrete. The crust went through stabilization-fracture-reformation periodic process, accompanied with accumulating and collapsing of molten concrete layer. The concrete surface temperature fluctuated around a low temperature and ablation temperature. It increased as the concrete surface layer was heated to melting, and dropped down when the cold concrete was revealed. The erosion progression was fast in the conditions of small jet diameter and large concrete inclination angle, and it was significantly faster in the erosion by metallic melt jet than by oxidic melt jet.

  7. Standard practice for radiologic examination of flat panel composites and sandwich core materials used in aerospace applications

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This practice is intended to be used as a supplement to Practices E 1742, E 1255, and E 2033. 1.2 This practice describes procedures for radiologic examination of flat panel composites and sandwich core materials made entirely or in part from fiber-reinforced polymer matrix composites. Radiologic examination is: a) radiographic (RT) with film, b) Computed Radiography (CR) with Imaging Plate, c) Digital Radiology (DR) with Digital Detector Array’s (DDA), and d) Radioscopic (RTR) Real Time Radiology with a detection system such as an Image Intensifier. The composite materials under consideration typically contain continuous high modulus fibers (> 20 GPa), such as those listed in 1.4. 1.3 This practice describes established radiological examination methods that are currently used by industry that have demonstrated utility in quality assurance of flat panel composites and sandwich core materials during product process design and optimization, process control, after manufacture inspection, in service exami...

  8. [Determination of major expansion properties of refractory die material compatible with slip casting core of sintered titanium powder].

    Science.gov (United States)

    Chao, Y; Kuang, X; Liao, Y; Wang, H

    1999-02-01

    To determinate major expansion properties of refractory die material. The setting expansion ratio of refractory die material for slip casting core of sintered titanium powder at room temperature was performed, as well as thermal expansion ratio from room temperature to 800 degrees C. The maximum setting expansion ratio in 2 hours reached 0.3407%; The final setting expansion ratio in 24 hours was 0.3117%; The mean thermal expansion coefficient was mainly in range of 8 x 10(-6)-11 x 10(-6)/degree C; The expansion property seemed very stable after sintering repeatedly and the small shrinkage after sintering could be compensated with the die spacer and setting expansion. The expansion properties of the refractory die material that we synthesized can fulfil the application requirements of slip casting core of sintered titanium powder.

  9. Comparative evaluation of shear bond strength of three resin based dual-cure core build-up materials: An In-vitro study.

    Science.gov (United States)

    Jain, Gaurav; Narad, Aditi; Boruah, Lalit C; Rajkumar, Balakrishnan

    2015-01-01

    The in-vitro study compared the shear bond strength (SBS) of three recently introduced dual-cure resin based core build-up materials namely ParaCore, FluoroCore, and MultiCore. One hundred twenty extracted permanent human mandibular molar teeth were taken and sectioned horizontally beneath the dentinoenamel junction to expose the coronal dentin. The specimens obtained were divided into three main groups based on the materials used and then further divided into four sub-groups based on time interval with ten samples each. The dentin surface was treated with the respective adhesives of the groups and then bulk filled with core build-up materials. The attained samples were than subjected to shear loading in Instron Universal Testing Machine. The data were tabulated and statistically analyzed using analysis of variance (ANOVA), Tukey's HSD, and Levene's test. The mean SBS was highest in MultiCore at all time periods as compared to FluoroCore and ParaCore and was also higher at 48 h thermocycling in all three groups studied. MultiCore dual-cure resin based core build-up material showed the highest mean SBS as compared to FluoroCore and ParaCore. SBS was not negatively affected by thermocycling.

  10. Material Weakening of Slip Zone Soils Induced by Water Level Fluctuation in the Ancient Landslides of Three Gorges Reservoir

    Directory of Open Access Journals (Sweden)

    Yu-Yong Jiao

    2014-01-01

    Full Text Available This experimental study investigated the effect of repeated wetting and drying on the reduction of slip zone soils taken from the Huangtupo landslide in the Three Gorges Reservoir, China. The variation process of the physical property and substance composition of the slip zone soils under the wetting-drying cycles was studied through liquid and plastic limit test and X-ray diffraction test. The results indicate that (1 the shearing strength of the slip zone soil dramatically decreased after one wetting-drying cycle and then gradually decreased until reaching a relatively stable state at the fourth cycle; (2 the plasticity index of the slip zone soil varied with increasing number of cycles and a variation process opposite to that of the strength value was observed; and (3 the clay mineral content in the slip zone soil increased and the calcite and quartz contents relatively decreased with increasing number of cycles. The variations in the plasticity index of the slip zone soil, as well as the increase in its clay mineral content, play important roles in the strength reduction. The results of this study provide a foundation for revealing the deformation and damage mechanism of landslides in reservoir banks.

  11. Study on preparation and microwave absorption property of the core-nanoshell composite materials doped with La.

    Science.gov (United States)

    Wei, Liqiu; Che, Ruxin; Jiang, Yijun; Yu, Bing

    2013-12-01

    Microwave absorbing material plays a great role in electromagnetic pollution controlling, electromagnetic interference shielding and stealth technology, etc. The core-nanoshell composite materials doped with La were prepared by a solid-state reaction method, which is applied to the electromagnetic wave absorption. The core is magnetic fly-ash hollow cenosphere, and the shell is the nanosized ferrite doped with La. The thermal decomposition process of the sample was investigated by thermogravimetry and differential thermal analysis. The morphology and components of the composite materials were investigated by the X-ray diffraction analysis, the microstructure was observed by scanning electron microscope and transmission electron microscope. The results of vibrating sample magnetometer analysis indicated that the exchange-coupling interaction happens between ferrite of magnetic fly-ash hollow cenosphere and nanosized ferrite coating, which caused outstanding magnetic properties. The microwave absorbing property of the sample was measured by reflectivity far field radar cross section of radar microwave absorbing material with vector network analyzer. The results indicated that the exchange-coupling interaction enhanced magnetic loss of composite materials. Therefore, in the frequency of 5 GHz, the reflection coefficient can achieve -24 dB. It is better than single material and is consistent with requirements of the microwave absorbing material at the low-frequency absorption. Copyright © 2013 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  12. Effect of varying core thicknesses and artificial aging on the color difference of different all-ceramic materials.

    Science.gov (United States)

    Dikicier, Sibel; Ayyildiz, Simel; Ozen, Julide; Sipahi, Cumhur

    2014-11-01

    Clinicians should reserve all-ceramics with high translucency for clinical applications in which high-level esthetics are required. Furthermore, it is unclear whether a correlation exists between core thickness and color change. The aim of this study was to examine the effects of different core thicknesses and artificial aging on the color stability of three all-ceramic systems. Ninety disc-shaped cores with different thicknesses (0.5 mm, 0.8 mm and 1.0 mm) were prepared from three all-ceramic systems, In-Ceram Alumina (IC), IPS e.max Press (EM) and Katana (K). The colors of the samples were measured with a spectrophotometer and the color parameters (L*, a*, b*, ΔE) were calculated according to the CIE L*a*b* (Commission Internationale de L'Eclairage) color system before and after aging. The effects of aging on color parameters were statistically significant (p ceramic materials tested.

  13. Study of diluting and absorber materials to control the reactivity during a postulated core meltdown accident in generation IV reactors

    International Nuclear Information System (INIS)

    Plevacova, Kamila

    2010-01-01

    In order to limit the consequences of a hypothetical core meltdown accident in Generation IV Sodium Fast Reactors, absorber materials in or near the core, such as boron carbide B 4 C, and diluting materials in the core catcher will be used to prevent recriticality within the mixture of molten oxide fuel and molten structures called corium. The aim of the PhD thesis was to select materials of both types and to understand their behaviour during their interaction with corium, from chemical and thermodynamic points of view. Concerning B 4 C, thermodynamic calculations and experiments agree with the formation of two immiscible phases at high temperature in the B 4 C - UO 2 system: one oxide and one boride. This separation of phases can reduce the efficiency of the neutrons absorption inside the molten fuel contained in the oxide phase. Moreover, volatilization of a part of the boron element can occur. According to these results, the necessary quantity of B 4 C to be introduced should be reconsidered for postulated severe accident sequence. Other solution could be the use of Eu 2 O 3 or HfO 2 as absorber material. These oxides form a solid solution with the oxide fuel. Concerning the diluting materials, mixed oxides Al 2 O 3 - HfO 2 and Al 2 O 3 - Eu 2 O 3 were preselected. These systems being completely unknown to date at high temperature in association with UO 2 , first points on the corresponding ternary phase diagrams were researched. Contrary to Al 2 O 3 - Eu 2 O 3 - UO 2 system, the Al 2 O 3 - HfO 2 - UO 2 mixture presents only one eutectic and thus only one solidification path which makes easier forecasting the behaviour of corium in the core catcher. (author)

  14. Study of diluting and absorber materials to control reactivity during a postulated core melt down accident in Generation IV reactors

    International Nuclear Information System (INIS)

    Plevacova, K.

    2010-01-01

    In order to limit the consequences of a hypothetical core meltdown accident in Generation IV Sodium Fast Reactors, absorber materials in or near the core, such as boron carbide B 4 C, and diluting materials in the core catcher will be used to prevent recriticality within the mixture of molten oxide fuel and molten structures called corium. The aim of the PhD thesis was to select materials of both types and to understand their behaviour during their interaction with corium, from chemical and thermodynamic point of view. Concerning B 4 C, thermodynamic calculations and experiments agree with the formation of two immiscible phases at high temperature in the B 4 C - UO 2 system: one oxide and one boride. This separation of phases can reduce the efficiency of the neutrons absorption inside the molten fuel contained in the oxide phase. Moreover, a volatilization of a part of the boron element can occur. According to these results, the necessary quantity of B 4 C to be introduced should be reconsidered for postulated severe accident sequence. Other solution could be the use of Eu 2 O 3 or HfO 2 as absorber material. These oxides form a solid solution with the oxide fuel. Concerning the diluting materials, mixed oxides Al 2 O 3 - HfO 2 and Al 2 O 3 - Eu 2 O 3 were preselected. These systems being completely unknown to date at high temperature in association with UO 2 , first points on the corresponding ternary phase diagrams were researched. Contrary to Al 2 O 3 - Eu 2 O 3 - UO 2 system, the Al 2 O 3 - HfO 2 - UO 2 mixture presents only one eutectic and thus only one solidification path which makes easier forecasting the behaviour of corium in the core catcher. (author) [fr

  15. Microleakage of composite resin and amalgam core material under complete cast crowns.

    Science.gov (United States)

    Larson, T D; Jensen, J R

    1980-07-01

    Ninety extracted human teeth were used to compare the microleakage of composite resin over, amalgam core, and regular crown preparations under a complete cast gold crown cemented with zinc phosphate cement as determined by 2% fluorescein dye solution. Specimens were compared with and without aging after cementation in a thermal bath by cycling some of them between 4 degrees C and 60 degrees C in a 2% fluorescein dye bath and others in a similar bath held at 37 degrees C. Fluorescein dye (under ultraviolet light) demonstrated microleakage of the specimens between the crown-tooth interface and the core-tooth interface. There were no significant differences in the microleakage due to aging. The specimens held at 37 degrees C in the fluorescein dye bath showed no significant differences between the core preparations and the regular crown preparations. However, when specimens were thermally cycled between 4 degrees C and 60 degrees C, there were significant differences. With thermal cycling, the regular crown preparations were better able to resist microleakage at the crown-tooth interface than either the composite resin core or the amalgam core preparations. The results of this investigation seem to indicate a need for further evaluation of core build-ups under cemented complete gold crowns.

  16. Hybridization of MOFs and COFs: A New Strategy for Construction of MOF@COF Core-Shell Hybrid Materials.

    Science.gov (United States)

    Peng, Yongwu; Zhao, Meiting; Chen, Bo; Zhang, Zhicheng; Huang, Ying; Dai, Fangna; Lai, Zhuangchai; Cui, Xiaoya; Tan, Chaoliang; Zhang, Hua

    2018-01-01

    The exploration of new porous hybrid materials is of great importance because of their unique properties and promising applications in separation of materials, catalysis, etc. Herein, for the first time, by integration of metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), a new type of MOF@COF core-shell hybrid material, i.e., NH 2 -MIL-68@TPA-COF, with high crystallinity and hierarchical pore structure, is synthesized. As a proof-of-concept application, the obtained NH 2 -MIL-68@TPA-COF hybrid material is used as an effective visible-light-driven photocatalyst for the degradation of rhodamine B. The synthetic strategy in this study opens up a new avenue for the construction of other MOF-COF hybrid materials, which could have various promising applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Effect of liner and core materials of plasterboard on microbial growth, spore-induced inflammatory responses, and cytotoxicity in macrophages.

    Science.gov (United States)

    Murtoniemi, Timo; Nevalainen, Aino; Suutari, Merja; Hirvonen, Maija-Riitta

    2002-11-01

    Microorganisms, when grown on wetted plasterboards, can produce bioactive compounds capable of inducing inflammatory and toxic reactions in mammalian cells. The paper liner of plasterboard is commonly regarded as the major substrate for microbial growth. In this study, we cultured Stachybotrys chartarum, Aspergillus versicolor, Penicillium spinulosum, and Streptomyces californicus on liners and cores of plasterboards in order to examine the role of these main plasterboard components on microbial growth and the resulting bioactivity, which was assessed as the ability of microbial spores to induce inflammatory responses and to evoke cytotoxicity in mouse macrophages. The microbes, isolated from mold problem buildings, were grown under saturated humidity conditions on wetted liners and cores of six different plasterboards. The spores were collected, applied to RAW264.7 macrophages at different doses, and evaluated 24 h after exposure for their ability to evoke cytotoxicity and to stimulate production of nitric oxide (NO), tumor necrosis factor alpha (TNFalpha), and interleukin-6 (IL-6). In general, microbial growth was better on the cores than on the liners. All of the studied microbes collected from cores induced a dose-dependent production of TNFalpha in macrophages. The TNFalpha production stimulated by spores of Stachybotrys, Aspergillus, and Streptomyces paralleled their cytotoxicity. Spores of Streptomyces and Aspergillus collected from liners were among the most potent inducers of NO and IL-6. Good growth of Stachybotrys on cores was associated with high cytotoxicity. Penicillium grew only on cores, but it did not induce major inflammatory mediator productions, nor was it significantly cytotoxic. These results indicate that previously reported microbial growth on plasterboards and spore-induced production of important inflammatory mediators and cell death in macrophages is not only due to the paper liner of plasterboard, but the core material also has a crucial

  18. The feasibility of small size specimens for testing of environmentally assisted cracking of irradiated materials and of materials under irradiation in reactor core

    Energy Technology Data Exchange (ETDEWEB)

    Toivonen, A.; Moilanen, P.; Pyykkoenen, M.; Taehtinen, S.; Rintamaa, R.; Saario, T. [Valtion Teknillinen Tutkimuskeskus, Espoo (Finland)

    1998-11-01

    Environmentally assisted cracking (EAC) of core materials has become an increasingly important issue of downtime and maintenance costs in nuclear power plants. Small size specimens are necessary in stress corrosion testing of irradiated materials because of difficulties in handling high dose rate materials and because of restricted availability of the materials. The drawback of using small size specimens is that in some cases they do not fulfil the requirements of the relevant testing standards. Recently VTT has developed J-R testing with irradiated and non-irradiated sub size 3 PB specimens, both in inert and in LWR environments. Also, a new materials testing system which will enable simultaneous multiple specimen testing both in laboratory conditions and in operating reactor core is under development. The new testing system will utilize Charpy and sub size 3 PB specimens. The feasibility study of the system has been carried out using different materials. Fracture resistance curves of a Cu-Zr-Cr alloy are shown to be independent of the specimen geometry and size, to some extent. Results gained from tests in simulated boiling water reactor (BWR) water are presented for sensitized SIS 2333 stainless steel. The experimental results indicate that the size of the plastic zone or stress triaxiality must be further studied although no significant effect on the environmentally assisted crack growth rate was observed. (orig.)

  19. Research Note:An approach to integrated assessement of reservoir siltation: the Joaquín Costa reservoir as a case study

    Directory of Open Access Journals (Sweden)

    A. Navas

    2004-01-01

    Full Text Available In 1932, the Esera river was dammed at the foothills of the Pyrenean External Ranges; since then, sedimentation has reduced its water storage capacity by a third. This study of the sediments in the Joaquín Costa reservoir has been based on detailed sedimentological examination and other analysis of mineralogy, grain size distribution and the chemical components of the materials accumulated at the bottom of the reservoir. Interpretations are based on results from four sediment cores collected at sites representative of the main environments in the reservoir. Records of known flood events and of reservoir management data have been combined with a 137Cs-derived chronology. Thus, it has been possible to ascribe the sedimentary record at the different reservoir environments to specific years, as well as some main changes in the facies types and sediment components. This methodology is a first approach to assessing siltation processes and dynamics in Mediterranean mountain reservoirs. Keywords: reservoir siltation, mineralogy, sedimentology,sedimentation rates, 137Cs, sediment tracing, mountain reservoir, central Spanish Pyrenees

  20. Innovative use of wood-plastic-composites (WPC) as a core material in the sandwich injection molding process

    Science.gov (United States)

    Moritzer, Elmar; Martin, Yannick

    2016-03-01

    The demand for materials based on renewable raw materials has risen steadily in recent years. With society's increasing interest for climate protection and sustainability, natural-based materials such as wood-plastic-composites (WPC) have gained market share thanks to their positive reputation. Due to advantages over unreinforced plastics such as cost reduction and weight savings it is possible to use WPC in a wide area of application. Additionally, an increase in mechanical properties such as rigidity and strength is achieved by the fibers compared to unreinforced polymers. The combination of plastic and wood combines the positive properties of both components in an innovative material. Despite the many positive properties of wood-plastic-composite, there are also negative characteristics that prevent the use of WPC in many product areas, such as automotive interiors. In particular, increased water intake, which may result in swelling of near-surface particles, increased odor emissions, poor surface textures and distortion of the components are unacceptable for many applications. The sandwich injection molding process can improve this situation by eliminating the negative properties of WPC by enclosing it with a pure polymer. In this case, a layered structure of skin and core material is produced, wherein the core component is completely enclosed by the skin component. The suitability of WPC as the core component in the sandwich injection molding has not yet been investigated. In this study the possibilities and limitations of the use of WPC are presented. The consideration of different fiber types, fiber contents, skin materials and its effect on the filling behavior are the focus of the presented analysis.

  1. Permeability restoration in underground disposal reservoirs

    International Nuclear Information System (INIS)

    Grubbs, D.M.; Haynes, C.D.; Whittle, G.P.

    1973-09-01

    The aim of the research performed was to explore methods of permeability restoration in underground disposal reservoirs that may improve the receptive capacity of a well to a level that will allow continued use of the disposal zone without resorting to elevated injection pressures. The laboratory investigation employed a simulated open-hole completion in a disposal well wherein the entire formation face is exposed to the well bore. Cylindrical core samples from representative reservoir rocks through which a central vertical opening or borehole had been drilled were injected with a liquid waste obtained from a chemical manufacturing plant. This particular waste material was found to have a moderate plugging effect when injected into samples of reservoir rocks in a prior study. A review was made of the chemical considerations that might account for the reduction of permeability in waste injection. Purpose of this study was to ascertain the conditions under which the precipitation of certain compounds might occur in the injection of the particular waste liquid employed. A summary of chemical calculations is contained in Appendix B. The data may be useful in the treatment of wastes prior to injection and in the design of restoration procedures where analyses of waste liquids and interstitial materials are available. The results of permeability restoration tests were analyzed mathematically by curve-fitting techniques performed by a digital computer. A summary of the analyses is set forth in the discussion of test results and examples of computer printouts are included in Appendix A

  2. [Determination of normal temperature properties of refractory die material compatible with slip casting core of sintered titanium powder].

    Science.gov (United States)

    Kuang, X; Liao, Y; Chao, Y; Wang, H

    1999-05-01

    The refractory die is the precondition for developing slip casting core of sintered powder. This study is to determine the normal temperature properties of the refractory die material compatible with slip casting core. to mix the die material at five different ratios (8/1, 7.5/1, 7/1, 6.5/1, and 6/1) and measure their solidification time with self-manufactured Vicker's needle; to prepare five cylindrical specimens (phi 10 x 15 mm) in different drying time for determining their compressive strength, and then to let another five specimens fire at 1000 degrees C four times for measuring the residual compressive strength at room temperature. The setting time was 16.25 minutes (7.5/1), and the lower the powder-liquid ratio, the longer the setting time. The normal compressive strength was 25.32 MPa (drying 24 hours), while the longer the drying time, the higher the compressive strength achieved (P die material meet the demand of slip casting core of sintered powder.

  3. TRITIUM RESERVOIR STRUCTURAL PERFORMANCE PREDICTION

    Energy Technology Data Exchange (ETDEWEB)

    Lam, P.S.; Morgan, M.J

    2005-11-10

    The burst test is used to assess the material performance of tritium reservoirs in the surveillance program in which reservoirs have been in service for extended periods of time. A materials system model and finite element procedure were developed under a Savannah River Site Plant-Directed Research and Development (PDRD) program to predict the structural response under a full range of loading and aged material conditions of the reservoir. The results show that the predicted burst pressure and volume ductility are in good agreement with the actual burst test results for the unexposed units. The material tensile properties used in the calculations were obtained from a curved tensile specimen harvested from a companion reservoir by Electric Discharge Machining (EDM). In the absence of exposed and aged material tensile data, literature data were used for demonstrating the methodology in terms of the helium-3 concentration in the metal and the depth of penetration in the reservoir sidewall. It can be shown that the volume ductility decreases significantly with the presence of tritium and its decay product, helium-3, in the metal, as was observed in the laboratory-controlled burst tests. The model and analytical procedure provides a predictive tool for reservoir structural integrity under aging conditions. It is recommended that benchmark tests and analysis for aged materials be performed. The methodology can be augmented to predict performance for reservoir with flaws.

  4. One-pot synthesis of silver@silica core-shell nanospheres and their application in optical limiting materials

    Science.gov (United States)

    Li, Chunfang; Wang, Chunlei; Ji, Zhaoyang; Jiang, Nengkai; Lin, Weihong; Li, Dongxiang

    2018-03-01

    Silica-coated metal nanoparticles are increasingly important for their many promising applications. A facile one-step synthesis of noble metal@silica core-shell nanospheres is necessary for their application in laser protection field. In this letter, a one-pot fabrication of silver@silica nanospheres was carried out, and then, silver nanoparticle-doped silicone rubber hybrid materials were prepared. Their optical limiting property to nanosecond laser was investigated and comparable optical limiting property with similar material involving multi-step synthesis of silica-coated metal nanoparticles was found.

  5. Heat Storage Performance of the Prefabricated Hollow Core Concrete Deck Element with Integrated Microencapsulated Phase Change Material

    DEFF Research Database (Denmark)

    Pomianowski, Michal Zbigniew; Heiselberg, Per; Jensen, Rasmus Lund

    2012-01-01

    The paper presents the numerically calculated dynamic heat storage capacity of the prefabricated hollow core concrete deck element with and without microencapsulated phase change material (PCM). The reference deck is the ordinary deck made of standard concrete material and that is broadly used...... in many emerging buildings. The new concrete deck with microencapsulated PCM is the standard deck on which one more layer with PCM concrete was added and at the same time the latent heat storage was introduced to the construction. The challenge to simulate the performance of the new deck with PCM concrete...

  6. The accretion of solar material onto white dwarfs: No mixing with core material implies that the mass of the white dwarf is increasing

    Directory of Open Access Journals (Sweden)

    Sumner Starrfield

    2014-02-01

    Full Text Available Cataclysmic Variables (CVs are close binary star systems with one component a white dwarf (WD and the other a larger cooler star that fills its Roche Lobe. The cooler star is losing mass through the inner Lagrangian point of the binary and some unknown fraction of this material is accreted by the WD. One consequence of the WDs accreting material, is the possibility that they are growing in mass and will eventually reach the Chandrasekhar Limit. This evolution could result in a Supernova Ia (SN Ia explosion and is designated the Single Degenerate Progenitor (SD scenario. This paper is concerned with the SD scenario for SN Ia progenitors. One problem with the single degenerate scenario is that it is generally assumed that the accreting material mixes with WD core material at some time during the accretion phase of evolution and, since the typical WD has a carbon-oxygen CO core, the mixing results in large amounts of carbon and oxygen being brought up into the accreted layers. The presence of enriched carbon causes enhanced nuclear fusion and a Classical Nova explosion. Both observations and theoretical studies of these explosions imply that more mass is ejected than is accreted. Thus, the WD in a Classical Nova system is losing mass and cannot be a SN Ia progenitor. However, the composition in the nuclear burning region is important and, in new calculations reported here, the consequences to the WD of no mixing of accreted material with core material have been investigated so that the material involved in the explosion has only a Solar composition. WDs with a large range in initial masses and mass accretion rates have been evolved. I find that once sufficient material has been accreted, nuclear burning occurs in all evolutionary sequences and continues until a thermonuclear runaway (TNR occurs and the WD either ejects a small amount of material or its radius grows to about 1012 cm and the evolution is ended. In all cases where mass ejection occurs

  7. Challenges of reservoir properties and production history matching in a CHOPS reservoir study

    Energy Technology Data Exchange (ETDEWEB)

    Alam, Mahbub [Department of Geoscience, University of Calgary (Canada)

    2011-07-01

    In order to meet increasing world energy demand, wells have to be drilled within very thin reservoir beds. This paper, we present one of the solutions for optimizing the reservoir characterization. Reservoir characterization is the process between the discovery of a property and the reservoir management phase. Principal data for reservoir modeling are: 4D Seismic interpretation, wireline log interpretation, core analysis, and petrophysical analysis. Reservoir conditions, perforation and completion technology are the key issues to the production rate of cold production. Reservoir modeling intends to minimize the risk factor, maximize production, and help determine the location for infill drillings. Cold heavy oil production with sand (CHOPS) is a method for enhancing primary production from heavy oil reservoirs. Gravitational forces, natural fluid pressure gradients and foamy oil flow phenomena are the major driving forces of the CHOPS mechanism. Finally, Reservoir characterization allows better understanding of permeability and porosity prediction.

  8. Technical meeting on assessment of core structural materials and surveillance programme of research reactors. Program and abstracts

    International Nuclear Information System (INIS)

    2010-01-01

    Research reactors have played and continue to play a key role in the development of the peaceful uses of nuclear energy and technology, particularly in various domains of research as, fundamental and applied science, industry, human health care and environmental studies, as well as nuclear energy applications and the development of nuclear science and technology related human resources. However, more than 50% of operating research reactors today are over 40 years old and continued operation has to be carefully assessed, especially from the structural materials point of view. In many instances data for the radiation-induced changes of research reactor core materials resulting from exposure to very high neutron fluences are not generally available. Further data is needed in order to evaluate the reliability of research reactor core components. Age-related degradation mechanisms can cause unplanned outages of the research reactors which could in many cases have been predicted by implementation of appropriate surveillance programs. Typically, neutron-based irradiation programmes are carried out at research reactors for several purposes, with particular attention to structural and moderator materials and fuel samples from conventional nuclear power plants. The aim of such experiments is to determine the neutron fluence effects on mechanical properties of materials. Research and development of new advanced materials is also carried out and many member states with research reactors are involved or interested in such R and D projects. Unfortunately, very little information from analysed structural materials can be used as inputs to evaluating research reactor structural materials because of marked differences in the materials and operating environment between power reactors and research reactors. However, the methods used in such programs could be applied to research reactors, especially in the preparation of a predictive/preventive maintenance program supporting extended

  9. Highly efficient phosphorescent materials based on Ir(iii) complexes-grafted on a polyhedral oligomeric silsesquioxane core.

    Science.gov (United States)

    Yu, Tianzhi; Xu, Zixuan; Su, Wenming; Zhao, Yuling; Zhang, Hui; Bao, Yanjun

    2016-09-14

    A new iridium(iii) complex containing a coumarin derivative as the cyclometalated ligand (L) and a carbazole-functionalized β-diketonate (Cz-acac-allyl) as the ancillary ligand, namely, Ir(iii) bis(3-(pyridin-2-yl)coumarinato-N,C(4))(1-(9-butyl-9H-carbazol-3-yl)hept-6-ene-1,3-dionato-O,O) [Ir(L)2(Cz-acac-allyl)], was firstly synthesized as the emissive iridium(iii) complex. Then three new phosphorescent polyhedral oligomeric silsesquioxane (POSS) materials, consisting of the emissive Ir(iii) complex and carbazole moieties covalently attached to a polyhedral oligomeric silsesquioxane (POSS) core were successfully synthesized by hydrosilylation reaction in the presence of platinum(0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane (Pt-dvs) as the catalyst. These phosphorescent POSS materials offer many advantages including amorphous properties, good thermal stabilities, and good solubility in common solvents, and high purity via column chromatography. The photoluminescence spectra of the POSS materials in solution and in the solid state indicate a reduction in the degrees of interactions among the Ir(iii) complex units and concentration quenching due to the bulky POSS core. Solution processed light-emitting devices based on these phosphorescent POSS materials exhibit a maximum external quantum efficiency (EQE) of 9.77%.

  10. Influence of Parameters of Core Bingham Material on Critical Behaviour of Three-Layered Annular Plate

    Science.gov (United States)

    Pawlus, Dorota

    2017-12-01

    The paper presents the dynamic response of annular three-layered plate subjected to loads variable in time. The plate is loaded in the plane of outer layers. The plate core has the electrorheological properties expressed by the Bingham body model. The dynamic stability loss of plate with elastic core is determined by the critical state parameters, particularly by the critical stresses. Numerous numerical observations show the influence of the values of viscosity constant and critical shear stresses, being the Bingham body parameters, on the supercritical viscous fluid plate behaviour. The problem has been solved analytically and numerically using the orthogonalization method and finite difference method. The solution includes both axisymmetric and asymmetric plate dynamic modes.

  11. Influence of reflector materials and core coolant on the characteristics of accelerator driven systems

    OpenAIRE

    Panza, Fabio; Osipenko, Michail; Ricco, Giovanni; Ripani, Marco; Saracco, Paolo

    2016-01-01

    In this paper we simulated the behavior of a simple ADS model, based on MOX fuel embedded in solid lead, in terms of multiplication coefficient keff, thermal power and absolute neutron spectra. In the first part of the paper, we report on the results obtained when modifying the reflector surrounding the fission core, by replacing pure lead with a layered graphite/lead structure. We found that, by appropriately choosing position and thickness of the graphite and lead layers, it is possible to ...

  12. Preparation and characterization of Phase change material microcapsules by a core-shell-like emulsion polymerization method

    Science.gov (United States)

    Ding, Li-ming; Pei, Guang-ling

    2015-07-01

    Phase change material microcapsules (MicroPCMs) were synthesized by a coreshell-like emulsion polymerization method. Styrene and methylacrylic acid copolymer (PS- MAA) was used as a wall material, and paraffin was used as a core material in order to prepare spherical, high resistance and high enthalpy MicroPCMs. Scanning Electron Microscope (SEM), laser particle size analyzer, Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetry (TG) and Differential Scanning Calorimeter (DSC) were employed to characterize the MicroPCMs. The results indicated that the average particle size of MicroPCMs was 42.29 μm, and the content of paraffin within microcapsules was 57.6%. The melting temperature and crystallization temperature were 30.7°C and 25.2°C.The melting enthalpy and crystallization enthalpy were -84.1 J/g and 91.3 J/g, respectively.

  13. Survival of extensively damaged endodontically treated incisors restored with different types of posts-and-core foundation restoration material.

    Science.gov (United States)

    Lazari, Priscilla Cardoso; de Carvalho, Marco Aurélio; Del Bel Cury, Altair A; Magne, Pascal

    2017-09-16

    analysis (log-rank post hoc test at α=.05 for pairwise comparisons). None of the tested specimen withstood all 140 000 cycles. All specimens without a ferrule were affected by an initial failure phenomenon (wide gap at the lingual margin between the core foundation restoration/crown assembly and the root). NfPfP, NfPt, and NfPtB had similar survival (29649 to 30987 mean cycles until initial failure). NfPfB outperformed NfPt and NfPtB. None of the post-and-core foundation restoration materials were able to match the performance of the ferrule group FPf (72667 cycles). In all groups, 100% of failures were catastrophic. The survival of extensively damaged endodontically treated incisors without a ferrule was slightly improved by the use of a fiber post with a bulk-fill composite resin core foundation restoration. However, none of the post-and-core techniques was able to compensate for the absence of a ferrule. The presence of the posts always adversely affected the failure mode. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  14. Reservoir characterization of Pennsylvanian Sandstone Reservoirs. Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Kelkar, M.

    1992-09-01

    This annual report describes the progress during the second year of a project on Reservoir Characterization of Pennsylvanian Sandstone Reservoirs. The report is divided into three sections: (i) reservoir description and scale-up procedures; (ii) outcrop investigation; (iii) in-fill drilling potential. The first section describes the methods by which a reservoir can be characterized, can be described in three dimensions, and can be scaled up with respect to its properties, appropriate for simulation purposes. The second section describes the progress on investigation of an outcrop. The outcrop is an analog of Bartlesville Sandstone. We have drilled ten wells behind the outcrop and collected extensive log and core data. The cores have been slabbed, photographed and the several plugs have been taken. In addition, minipermeameter is used to measure permeabilities on the core surface at six inch intervals. The plugs have been analyzed for the permeability and porosity values. The variations in property values will be tied to the geological descriptions as well as the subsurface data collected from the Glen Pool field. The third section discusses the application of geostatistical techniques to infer in-fill well locations. The geostatistical technique used is the simulated annealing technique because of its flexibility. One of the important reservoir data is the production data. Use of production data will allow us to define the reservoir continuities, which may in turn, determine the in-fill well locations. The proposed technique allows us to incorporate some of the production data as constraints in the reservoir descriptions. The technique has been validated by comparing the results with numerical simulations.

  15. Estimation of fracture parameters in foam core materials using thermal techniques

    DEFF Research Database (Denmark)

    Dulieu-Barton, J. M.; Berggreen, Christian; Boyenval Langlois, C.

    2010-01-01

    The paper presents some initial work on establishing the stress state at a crack tip in PVC foam material using a non-contact infra-red technique known as thermoelastic stress analysis (TSA). A parametric study of the factors that may affect the thermoelastic response of the foam material...

  16. Effect of filling materials on femoral head stress following core decompression

    International Nuclear Information System (INIS)

    Chen Zhiping; Qi Zhenxi

    2010-01-01

    Objective: To examine the effect of elastic modulus of filling materials on femoral head stress. Methods: A normal femur specimen was chosen from an adult male and CT scanning was conducted at 2 mm interval along cross section to get the images of cross sections. The images were then inputted into computer to get contour of femur and rebuild 3D model. The pretreatment was managed by ANSYS9. 0. Five bone models were built, and the hip joint reaction force, the abductor muscle force, the Iliopsoas force and the vastus lateralis muscle force were applied according to the Three-dimensional space distribution of femur force under physiological state. Results: The maximum subchondral bone plate stresswould decrease by using high elastic modulus filling materials, while the stress would increase by using low elastic modulus filling materials. The implantation of two kinds of filling bone materials would both cause stress concentration on the interface. By using gradient method which treated implant materials as functionally graded material and stratified implant materials according to their elastic modulus, the stress concentration on interface decreased significantly. Conclusion: The gradient method and high elastic modulus implant material stratification can effectively reduce the stress on subchondral bone plate and the stress on cancellous bone under bony plate, and reduce stress concentration on the interface greatly so as to prevent femoral head collapse effectively. (authors)

  17. Impact of wall materials and seeding gases on the pedestal and on core plasma performance

    Directory of Open Access Journals (Sweden)

    E. Wolfrum

    2017-08-01

    Full Text Available Plasmas in machines with all metal plasma facing components have a lower Zeff, less radiation cooling in the scrape-off layer and divertor regions and are prone to impurity accumulation in the core. Higher gas puff and the seeding of low-Z impurities are applied to prevent impurity accumulation, to increase the frequency of edge localised modes and to cool the divertor. A lower power threshold for the transition from low-confinement mode to high confinement mode has been found in all metal wall machines when compared to carbon wall machines. The application of lithium before or during discharges can lead to ELM free H-modes. The seeding of high-Z impurities increases core radiation, reduces the power flux across the separatrix and, if applied in the right amount, does not lead to deterioration of the confinement. All these effects have in common that they can often be explained by the shape or position of the density profile. Not only the peakedness of the density profile in the core but also the position of the edge pressure gradient influences global confinement. It is shown how (i ionisation in the pedestal region due to higher reflection of deuterium from high-Z walls, (ii reduced recycling in consequence of lithium wall conditioning, (iii the fostering of edge modes with lithium dropping, (iv increased gas puff and (v the cooling of the scrape-off layer by medium-Z impurities such as nitrogen affect the edge density profile. The consequence is a shift in the pressure profile relative to the separatrix, leading to improved pedestal stability of H-mode plasmas when the direction is inwards.

  18. Single-step generation of fluorophore-encapsulated gold nanoparticle core-shell materials

    International Nuclear Information System (INIS)

    Sardar, R; Shem, P M; Pecchia-Bekkum, C; Bjorge, N S; Shumaker-Parry, J S

    2010-01-01

    We report a simple route to produce fluorophore-encapsulated gold nanoparticles (AuNPs) in a single step under aqueous conditions using the fluorophore 1-pyrenemethylamine (PMA). Different amounts of PMA were used and the resulting core-shell gold nanoparticles were analyzed using UV-visible absorption spectroscopy, fluorescence spectroscopy, and transmission and scanning electron microscopy. Electron microscopy analysis shows nanoparticles consisting of a gold nanoparticle core which is encapsulated with a lower contrast shell. In the UV-visible spectra, we observed a significant red shift (37 nm) of the localized surface plasmon resonance (LSPR) absorption maximum (λ max ) compared to citrate-stabilized AuNPs of a similar size. We attribute the prominent LSPR wavelength shift for PMA-AuNP conjugates to the increase in the local dielectric environment near the gold nanoparticles due to the shell formation. This simple, aqueous-based synthesis is a new approach to the production of fluorophore-encapsulated AuNPs that could be applicable in biological sensing systems and photonic device fabrication.

  19. In core instrumentation for online nuclear heating measurements of material testing reactor

    International Nuclear Information System (INIS)

    Reynard, C.; Andre, J.; Brun, J.; Carette, M.; Janulyte, A.; Merroun, O.; Zerega, Y.; Lyoussi, A.; Bignan, G.; Chauvin, J-P.; Fourmentel, D.; Glayse, W.; Gonnier, C.; Guimbal, P.; Iracane, D.; Villard, J.-F.

    2010-01-01

    The present work focuses on nuclear heating. This work belongs to a new advanced research program called IN-CORE which means 'Instrumentation for Nuclear radiations and Calorimetry Online in REactor' between the LCP (University of Provence-CNRS) and the CEA (French Atomic Energy Commission) - Jules Horowitz Reactor (JHR) program. This program started in September 2009 and is dedicated to the conception and the design of an innovative mobile experimental device coupling several sensors and ray detectors for on line measurements of relevant physical parameters (photonic heating, neutronic flux ...) and for an accurate parametric mapping of experimental channels in the JHR Core. The work presented below is the first step of this program and concerns a brief state of the art related to measurement methods of nuclear heating phenomena in research reactor in general and MTR in particular. A special care is given to gamma heating measurements. A first part deals with numerical codes and models. The second one presents instrumentation divided into various kinds of sensor such as calorimeter measurements and gamma ionization chamber measurements. Their basic principles, characteristics such as metrological parameters, operating mode, disadvantages/advantages, ... are discussed. (author)

  20. Spirobifluorene Core-Based Novel Hole Transporting Materials for Red Phosphorescence OLEDs

    Directory of Open Access Journals (Sweden)

    Ramanaskanda Braveenth

    2017-03-01

    Full Text Available Two new hole transporting materials, named HTM 1A and HTM 1B, were designed and synthesized in significant yields using the well-known Buchwald Hartwig and Suzuki cross- coupling reactions. Both materials showed higher decomposition temperatures (over 450 °C at 5% weight reduction and HTM 1B exhibited a higher glass transition temperature of 180 °C. Red phosphorescence-based OLED devices were fabricated to analyze the device performances compared to Spiro-NPB and NPB as reference hole transporting materials. Devices consist of hole transporting material as HTM 1B showed better maximum current and power efficiencies of 16.16 cd/A and 11.17 lm/W, at the same time it revealed an improved external quantum efficiency of 13.64%. This efficiency is considerably higher than that of Spiro-NPB and NPB-based reference devices.

  1. Effects of different surface treatments on the bond strength of glass fiber-reinforced composite root canal posts to composite core material

    Directory of Open Access Journals (Sweden)

    Murat Kurt

    2012-03-01

    Conclusion: Er:YAG laser treatments on the FRC post surface decreased the bond strength. Airborne-particle abrasion and HF acid etching are alternative methods for increasing bond strength of FRC posts to composite core material.

  2. Chemical interactions of reactor core materials up to very high temperatures

    International Nuclear Information System (INIS)

    Hofmann, P.; Hagen, S.; Schanz, G.; Skokan, A.

    1989-01-01

    The paper describes which chemical interactions may occur in a LWR fuel rod bundle containing (Ag, In, Cd) absorber rods or (Al 2 O 3 /B 4 C) burnable poison rods with increasing temperature up to the complete melting of the components and the formed reaction products. The kinetics of the most important chemical interactions has been investigated and the results are described. In most cases the reaction products have lower melting points or ranges than the original components. This results in a relocation of liquefied components often far below their melting points. There exist three distinct temperature regimes in which liquid phases can form in the core in differently large quantities. These temperature regimes are described in detail. The phase relations in the important ternary (U, Zr, O) system have been extensively studied. The effect of steel constituents on the phase relations is given in addition. All the considerations are focused on PWR conditions only. (orig.) [de

  3. A Comparative Study on Damage Mechanism of Sandwich Structures with Different Core Materials under Lightning Strikes

    Directory of Open Access Journals (Sweden)

    Jiangyan Yan

    2017-10-01

    Full Text Available Wind turbine blades are easily struck by lightning, a phenomenon that has attracted more and more attention in recent years. On this subject a large current experiment was conducted on three typical blade sandwich structures to simulate the natural lightning-induced arc effects. The resulting damage to different composite materials has been compared: polyvinyl chloride (PVC and polyethylene terephthalate (PET suffered pyrolysis and cracks inside, while the damage to balsa wood was fibers breaking off and large delamination between it and the resin layer, and only a little chemical pyrolysis. To analyze the damage mechanism on sandwich structures of different materials, a finite element method (FEM model to calculate the temperature and pressure distribution was built, taking into consideration heat transfer and flow expansion due to impulse currents. According to the simulation results, PVC had the most severe temperature and pressure distribution, while PET and balsa wood were in the better condition after the experiments. The temperature distribution results explained clearly why balsa wood suffered much less chemical pyrolysis than PVC. Since balsa wood had better thermal stability than PET, the pyrolysis area of PET was obviously larger than that of balsa wood too. Increasing the volume fraction of solid components of porous materials can efficiently decrease the heat transfer velocity in porous materials. Permeability didn’t influence that much. The findings provide support for optimum material selection and design in blade manufacturing.

  4. Design and preliminary analysis of in-vessel core catcher made of high-temperature ceramics material in PWR

    International Nuclear Information System (INIS)

    Xu Hong; Ma Li; Wang Junrong; Zhou Zhiwei

    2011-01-01

    In order to protect the interior wall of pressure vessel from melting, as an additional way to external reactor vessel cooling (ERVC), a kind of in-vessel core catcher (IVCC) made of high-temperature ceramics material was designed. Through the high-temperature and thermal-resistance characteristic of IVCC, the distributing of heat flux was optimized. The results show that the downward average heat flux from melt in ceramic layer reduces obviously and the interior wall of pressure vessel doesn't melt, keeping its integrity perfectly. Increasing of upward heat flux from metallic layer makes the upper plenum structure's temperature ascend, but the temperature doesn't exceed its melting point. In conclusion, the results indicate the potential feasibility of IVCC made of high-temperature ceramics material. (authors)

  5. Nano-magnetic particles used in biomedicine: core and coating materials.

    Science.gov (United States)

    Karimi, Z; Karimi, L; Shokrollahi, H

    2013-07-01

    Magnetic nanoparticles for medical applications have been developed by many researchers. Separation, immunoassay, drug delivery, magnetic resonance imaging and hyperthermia are enhanced by the use of suitable magnetic nanoparticles and coating materials in the form of ferrofluids. Due to their low biocompatibility and low dispersion in water solutions, nanoparticles that are used for biomedical applications require surface treatment. Various kinds of coating materials including organic materials (polymers), inorganic metals (gold, platinum) or metal oxides (aluminum oxide, cobalt oxide) have been attracted during the last few years. Based on the recent advances and the importance of nanomedicine in human life, this paper attempts to give a brief summary on the different ferrite nano-magnetic particles and coatings used in nanomedicine. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Transformer core

    NARCIS (Netherlands)

    Mehendale, A.; Hagedoorn, Wouter; Lötters, Joost Conrad

    2010-01-01

    A transformer core includes a stack of a plurality of planar core plates of a magnetically permeable material, which plates each consist of a first and a second sub-part that together enclose at least one opening. The sub-parts can be fitted together via contact faces that are located on either side

  7. Transformer core

    NARCIS (Netherlands)

    Mehendale, A.; Hagedoorn, Wouter; Lötters, Joost Conrad

    2008-01-01

    A transformer core includes a stack of a plurality of planar core plates of a magnetically permeable material, which plates each consist of a first and a second sub-part that together enclose at least one opening. The sub-parts can be fitted together via contact faces that are located on either side

  8. A resin composite material containing an eugenol derivative for intracanal post cementation and core build-up restoration.

    Science.gov (United States)

    Almaroof, A; Rojo, L; Mannocci, F; Deb, S

    2016-02-01

    To formulate and evaluate new dual cured resin composite based on the inclusion of eugenyl methacrylate monomer (EgMA) with Bis-GMA/TEGDMA resin systems for intracanal post cementation and core build-up restoration of endodontically treated teeth. EgMA was synthesized and incorporated at 5% (BTEg5) or 10% (BTEg10) into dual-cure formulations. Curing properties, viscosity, Tg, radiopacity, static and dynamic mechanical properties of the composites were determined and compared with Clearfil™DC Core-Plus, a commercial dual-cure, two-component composite. Statistical analysis of the data was performed with ANOVA and the Tukey's post-hoc test. The experimental composites were successfully prepared, which exhibited excellent curing depths of 4.9, 4.7 and 4.2 mm for BTEg0, BTEg5 and BTEg10 respectively, which were significantly higher than Clearfil™DC. However, the inclusion of EgMA initially led to a lower degree of cure, which increased when measured at 24 h with values comparable to formulations without EgMA, indicating post-curing. The inclusion of EgMA also lowered the polymerization exotherm thereby reducing the potential of thermal damage to host tissue. Both thermal and viscoelastic analyses confirmed the ability of the monomer to reduce the stiffness of the composites by forming a branched network. The compressive strength of BTEg5 was significantly higher than the control whilst flexural strength increased significantly from 95.9 to 114.8 MPa (BTEg5) and 121.9 MPa (BTEg10). Radiopacity of the composites was equivalent to ∼3 mm Al allowing efficient diagnosis. The incorporation of EgMA within polymerizable formulations provides a novel approach to prepare reinforced resin composite material for intracanal post cementation and core build-up and the potential to impart antibacterial properties of eugenol to endodontic restorations. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  9. Thermoelastic properties of the Rotokawa Andesite: A geothermal reservoir constraint

    Science.gov (United States)

    Siratovich, P. A.; von Aulock, F. W.; Lavallée, Y.; Cole, J. W.; Kennedy, B. M.; Villeneuve, M. C.

    2015-08-01

    Knowledge of the thermal properties of geothermal reservoir rocks is essential to constraining important engineering concerns such as wellbore stability, reservoir forecasting and stimulation procedures. The thermo-mechanical evolution of geological material is also important to assess when considering natural processes such as magmatic dyke propagation, contact metamorphism and magma/lava emplacement and cooling effects. To better constrain these properties in the geothermal reservoir, thermal measurements were carried out on core samples from production wells drilled in the Rotokawa Andesite geothermal reservoir, located in the Taupo Volcanic Zone, New Zealand. Linear thermal expansion testing, thermogravimetric analysis, and differential scanning calorimetry were used, employing experimental heating rates of 2, 5 and 20 °C/min. Thermal property analyses can elucidate whether thermal expansion values measured under varied heating (and cooling) rates are rate dependent and if thermo-chemical reactions influence the resultant expansivity. Measured thermal expansion coefficients of the Rotokawa Andesite are shown not to be heating rate dependent. We have also found that significant thermochemical reactions occur during heating above 500 °C resulting in non-reversible changes to the thermomechanical properties. The combined thermogravimetric, calorimetric and thermomechanical analysis allows insight to the reactions occurring and how the thermomechanical properties are affected at high temperature. We incorporated results of tensile strength testing on the Rotokawa Andesite to apply our thermal property measurements to a one-dimensional thermal stress model. The developed model provides a failure criterion for the Rotokawa Andesite under thermal stress. The importance of this study is to further understand the critical heating and cooling rates at which thermal stress may cause cracking within the Rotokawa reservoir. Thermal cracking in the reservoir can be

  10. Easily oxidizable triarylamine materials with naphthalene and binaphthalene core: structure-properties relationship

    Czech Academy of Sciences Publication Activity Database

    Kerner, L.; Gmucová, K.; Kožíšek, J.; Petříček, Václav; Putala, M.

    2016-01-01

    Roč. 72, č. 44 (2016), s. 7081-7092 ISSN 0040-4020 R&D Projects: GA ČR(CZ) GA14-03276S Institutional support: RVO:68378271 Keywords : triphenylamine * carbazole * regioselective amination * Sonogashira coupling * Negishi alkynylation * hole-transporting materials * OLED * cyclic voltammetry Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.651, year: 2016

  11. Analytical core loss calculations for magnetic materials used in high frequency high power converter applications. Ph.D. Thesis - Toledo Univ.

    Science.gov (United States)

    Triner, J. E.

    1979-01-01

    The basic magnetic properties under various operating conditions encountered in the state-of-the-art DC-AC/DC converters are examined. Using a novel core excitation circuit, the basic B-H and loss characteristics of various core materials may be observed as a function of circuit configuration, frequency of operation, input voltage, and pulse-width modulation conditions. From this empirical data, a mathematical loss characteristics equation is developed to analytically predict the specific core loss of several magnetic materials under various waveform excitation conditions.

  12. A systematic review of dowel (post) and core materials and systems.

    Science.gov (United States)

    Theodosopoulou, Joanna N; Chochlidakis, Konstantinos M

    2009-08-01

    The aim of this systematic review was to determine which dowel (post) and core system is the most successful when used in vivo to restore endodontically treated teeth. A MEDLINE, a Cochrane, and an EMBASE search (three specified searches) were conducted to identify randomized (RCT) and nonrandomized controlled clinical trials (CCT), cohort (CS), and case control studies (CCS) until January 2008, conducted on humans, and published in English, German, and French, relating to dowel and core systems for restoring endodontically treated teeth. Also, a hand search was conducted, along with contact with the authors when needed. The MEDLINE, Cochrane, and EMBASE searches identified 997, 141, and 25 published articles, respectively. Ten articles from the MEDLINE and seven articles from the Cochrane search (that were also identified in the MEDLINE search) met the inclusion and validity assessment criteria. Six out of the ten studies were RCTs, two were CCTs, and two CSs. The RCT studies suggest that carbon fiber in resin matrix dowels are significantly better than precious alloy cast dowels (number needed to treat, NNT = 8.30). Tapered gold alloy cast dowels are better than ParaPost gold alloy cast dowels (NNT = 13.15). ParaPost prefabricated dowels are slightly better than ParaPost cast dowels (NNT = 175.4). Glass fiber dowels are significantly better than metal screw dowels (NNT = 5.46), but worse than titanium (NNT =-21.73) (moderately). Carbon fiber dowels are worse than gold alloy cast dowels (significantly) (NNT =-5.81) and than amalgam dowels (NNT =-125) (slightly). The CCT studies suggest that metal dowels are better (NNT = 21.73) but also worse than cast dowels (NNT =-33.33) depending on the remaining amount of coronal hard tissue. Quartz fiber dowels show success rates similar to and worse than glass fiber-reinforced dowels (NNT =-37.03). The results from the CS studies suggest that carbon fiber in resin matrix dowels are better (moderately) than carbon fiber

  13. Proceedings of JSPS-CAS core university program seminar on target materials

    International Nuclear Information System (INIS)

    Gu, Z.Z.; Norimatsu, T.

    2008-02-01

    China-Japan Bilateral Collaboration on the Study of Ultrahigh Density Plasma has been established since 2001 and its second phase is conducting from 2006. Target materials are key issue of the Study of Ultrahigh Density Plasma, and the second of target fabrication was opened at the 2005 Workshop on Ultrahigh Density Plasma Production, Application and theory for Laser Fusion at Nine Village Valley, Sichuan. It achieved great successes in high-level academic exchange and efficient presentation of state-of-the-art development in this research field. However, in order to attract greater attention and participation of more scientists in these fields, the organizing committee decided to further specify and enlarge the scale of the workshop to be China-Japan Bilateral Seminar on Target Materials 2007 in Huang Shan in southern Anhui Province of east China. The seminar had more than 20 participants from 7 universities and 3 institutes in Japan and China. They exchanged state-of-the-art development in nanomaterials, capsule fabrication and low density materials toward target of high power laser. This issue is the collection of the paper presented at the seminar. The 17 of the presented papers are indexed individually. (J.P.N.)

  14. Fissile core and Tritium-Breeding Blanket: structural materials and their requirements

    Science.gov (United States)

    Boutard, Jean-Louis; Alamo, Ana; Lindau, Rainer; Rieth, Michael

    2008-04-01

    High radiation resistant structural materials for fusion and fission nuclear power plants are a key issue for the development of both types of reactors. Selection criteria, elements of metallurgy of the selected materials, and the major issues as they are revealed by the results of the present development programmes, are presented. At low temperature (˜300 °C) ferritic/martensitic steels are suffering from He-embrittlement, associated with possible hardening due to α/α unmixing. The kinetics of hardening and embrittlement versus dose, especially saturation with dose, are still open key issues, difficult to settle on the basis of a purely experimental programme. Important progress is still to be made in mastering the initial microstructure, inclusion cleanness and joining techniques of oxide dispersion strengthened steels for higher heat resistance. Physics modeling as presented in this issue should promote guidance to the understanding of the mechanisms involved, provide solutions to master the initial microstructure and phase stability, and mitigate the in-service property degradation. To cite this article: J.-L. Boutard et al., C. R. Physique 9 (2008).

  15. Experimental investigation of material chemical effects on emergency core cooling pump suction filter performance after loss of coolant accident

    International Nuclear Information System (INIS)

    Park, Jong Woon; Park, Byung Gi; Kim, Chang Hyun

    2009-01-01

    Integral tests of head loss through an emergency core cooling filter screen are conducted, simulating reactor building environmental conditions for 30 days after a loss of coolant accident. A test rig with five individual loops each of whose chamber is established to test chemical product formation and measure the head loss through a sample filter. The screen area at each chamber and the amounts of reactor building materials are scaled down according to specific plant condition. A series of tests have been performed to investigate the effects of calcium-silicate, reactor building spray, existence of calcium-silicate with tri-sodium phosphate (TSP), and composition of materials. The results showed that head loss across the chemical bed with even a small amount of calcium-silicate insulation instantaneously increased as soon as TSP was added to the test solution. Also, the head loss across the filter screen is strongly affected by spray duration and the head loss increase is rapid at the early stage, because of high dissolution and precipitation of aluminum and zinc. After passivation of aluminum and zinc by corrosion, the head loss increase is much slowed down and is mainly induced by materials such as calcium, silicon, and magnesium leached from NUKON TM and concrete. Furthermore, it is newly found that the spay buffer agent, tri-sodium phosphate, to form protective coating on the aluminum surface and reduce aluminum leaching is not effective for a large amount of aluminum and a long spray.

  16. In-core instrumentation and in-situ measurement in connection with fuel behaviour. Working material

    International Nuclear Information System (INIS)

    1996-01-01

    The subject of this meeting has been touched on briefly in most of the Specialist's and topical meetings related to fuel behaviour. On the basis of the conclusions and recommendations of these meetings the International Working Group on Water Reactor Fuel Performance and Technology (IWGFPT) recommended the Agency to organize a dedicated Specialist's Meeting on the subject. The twenty one papers covered the instrumentation, sensors, methods and computer codes currently used in Material Test Reactor (MTR) and power reactors as well as improved instrumentation and methods. The meeting acknowledged the fast development of fuel modelling and therefore the growing need of dedicated high burnup fuel experiments carried out in MTR reactors on refabricated rods from power reactors. In order to reduce safety margins in power reactors, thus improving economics, the necessity to develop more sophisticated on-line calculations, based on improved sensors, was recognized, although this development is limited by insufficient knowledge of the mechanisms involved. Refs, figs, tabs

  17. PLANET TOPERS: Planets, Tracing the Transfer, Origin, Preservation, and Evolution of their ReservoirS.

    Science.gov (United States)

    Dehant, V; Asael, D; Baland, R M; Baludikay, B K; Beghin, J; Belza, J; Beuthe, M; Breuer, D; Chernonozhkin, S; Claeys, Ph; Cornet, Y; Cornet, L; Coyette, A; Debaille, V; Delvigne, C; Deproost, M H; De WInter, N; Duchemin, C; El Atrassi, F; François, C; De Keyser, J; Gillmann, C; Gloesener, E; Goderis, S; Hidaka, Y; Höning, D; Huber, M; Hublet, G; Javaux, E J; Karatekin, Ö; Kodolanyi, J; Revilla, L Lobo; Maes, L; Maggiolo, R; Mattielli, N; Maurice, M; McKibbin, S; Morschhauser, A; Neumann, W; Noack, L; Pham, L B S; Pittarello, L; Plesa, A C; Rivoldini, A; Robert, S; Rosenblatt, P; Spohn, T; Storme, J -Y; Tosi, N; Trinh, A; Valdes, M; Vandaele, A C; Vanhaecke, F; Van Hoolst, T; Van Roosbroek, N; Wilquet, V; Yseboodt, M

    2016-11-01

    The Interuniversity Attraction Pole (IAP) 'PLANET TOPERS' (Planets: Tracing the Transfer, Origin, Preservation, and Evolution of their Reservoirs) addresses the fundamental understanding of the thermal and compositional evolution of the different reservoirs of planetary bodies (core, mantle, crust, atmosphere, hydrosphere, cryosphere, and space) considering interactions and feedback mechanisms. Here we present the first results after 2 years of project work.

  18. Honeycomb core material for sandwich construction - with common hexagonal walls bonded by thermoplastic resin and free walls carrying layer of resin and masking agent

    NARCIS (Netherlands)

    Undetermined, U.

    1991-01-01

    Abstract of NL 8902116 (A) In a honeycomb core material for a sandwich construction, the common hexagonal walls are bonded together by a thermoplastic resin, and the free hexagonal walls carry a layer of the same resin and also a masking agent. - A number of plates of raw material are given strips

  19. EXPLOITATION AND OPTIMIZATION OF RESERVOIR PERFORMANCE IN HUNTON FORMATION, OKLAHOMA

    Energy Technology Data Exchange (ETDEWEB)

    Mohan Kelkar

    2003-10-01

    This report presents the work done so far on Hunton Formation in West Carney Field in Lincoln County, Oklahoma. West Carney Field produces oil and gas from the Hunton Formation. The field was developed starting in 1995. Some of the unique characteristics of the field include decreasing water oil ratio over time, decreasing gas-oil ratio at the beginning of production, inability to calculate oil reserves in the field based on log data, and sustained oil rates over long periods of time. To understand the unique characteristics of the field, an integrated evaluation was undertaken. Production data from the field were meticulously collected, and over forty wells were cored and logged to better understand the petrophysical and engineering characteristics. Based on the work done in this budget period so far, some of the preliminary conclusions can be listed as follows: (1) Based on PVT analysis, the field most likely contains volatile oil with bubble point close to initial reservoir pressure of 1,900 psia. (2) The initial oil in place, which is contact with existing wells, can be determined by newly developed material balance technique. The oil in place, which is in communication, is significantly less than determined by volumetric analysis, indicating heterogeneous nature of the reservoir. The oil in place, determined by material balance, is greater than determined by decline curve analysis. This difference may lead to additional locations for in fill wells. (3) The core and log evaluation indicates that the intermediate pores (porosity between 2 and 6 %) are very important in determining production potential of the reservoir. These intermediate size pores contain high oil saturation. (4) The limestone part of the reservoir, although low in porosity (mostly less than 6 %) is much more prolific in terms of oil production than the dolomite portion of the reservoir. The reason for this difference is the higher oil saturation in low porosity region. As the average porosity

  20. Mathematical modelling of powder material motion and transportation in high-temperature flow core during plasma coatings application

    Science.gov (United States)

    Bogdanovich, V. I.; Giorbelidze, M. G.

    2018-03-01

    A problem of mathematical modelling of powder material motion and transportation in gas thermal flow core has been addressed. Undertaken studies indicate significant impact on dynamics of motion of sprayed particles of phenomenological law for drag coefficient and accounting momentum loss of a plasma jet upon acceleration of these particles and their diameter. It is determined that at great dispersion of spraying particles, they reach detail surface at different velocity and significant particles separation takes place at spraying spot. According to the results of mathematical modelling, requirements for admissible dispersion of diameters of particles used for spraying have been formulated. Research has also allowed reducing separation of particles at the spraying spot due to the selection of the method of powder feed to the anode channel of the plasma torch.

  1. Push-out bond strength and dentinal tubule penetration of different root canal sealers used with coated core materials

    Science.gov (United States)

    Purali, Nuhan; Coşgun, Erdal; Calt, Semra

    2016-01-01

    Objectives The aim of this study was to compare the push-out bond strength and dentinal tubule penetration of root canal sealers used with coated core materials and conventional gutta-percha. Materials and Methods A total of 72 single-rooted human mandibular incisors were instrumented with NiTi rotary files with irrigation of 2.5% NaOCl. The smear layer was removed with 17% ethylenediaminetetraacetic acid (EDTA). Specimens were assigned into four groups according to the obturation system: Group 1, EndoRez (Ultradent Product Inc.); Group 2, Activ GP (Brasseler); Group 3, SmartSeal (DFRP Ltd. Villa Farm); Group 4, AH 26 (Dentsply de Trey)/gutta-percha (GP). For push-out bond strength measurement, two horizontal slices were obtained from each specimen (n = 20). To compare dentinal tubule penetration, remaining 32 roots assigned to 4 groups as above were obturated with 0.1% Rhodamine B labeled sealers. One horizontal slice was obtained from the middle third of each specimen (n = 8) and scanned under confocal laser scanning electron microscope. Tubule penetration area, depth, and percentage were measured. Kruskall-Wallis test was used for statistical analysis. Results EndoRez showed significantly lower push-out bond strength than the others (p penetration. SmartSeal showed the least penetration than the others (p penetration of resin-and glass ionomer-based sealers used with coated core was not superior to resin-based sealer used with conventional GP. Dentinal tubule penetration has limited effect on bond strength. The use of conventional GP with sealer seems to be sufficient in terms of push-out bond strength. PMID:27200279

  2. Self-Assembly of Crystalline Structures of Magnetic Core-Shell Nanoparticles for Fabrication of Nanostructured Materials.

    Science.gov (United States)

    Xue, Xiaozheng; Wang, Jianchao; Furlani, Edward P

    2015-10-14

    A theoretical study is presented of the template-assisted formation of crystalline superstructures of magnetic-dielectric core-shell particles. The templates produce highly localized gradient fields and a corresponding magnetic force that guides the assembly with nanoscale precision in particle placement. The process is studied using two distinct and complementary computational models that predict the dynamics and energy of the particles, respectively. Both mono- and polydisperse colloids are studied, and the analysis demonstrates for the first time that although the particles self-assemble into ordered crystalline superstructures, the particle formation is not unique. There is a Brownian motion-induced degeneracy in the process wherein various distinct, energetically comparable crystalline structures can form for a given template geometry. The models predict the formation of hexagonal close packed (HCP) and face centered cubic (FCC) structures as well as mixed phase structures due to in-plane stacking disorders, which is consistent with experimental observations. The polydisperse particle structures are less uniform than the monodisperse particle structures because of the irregular packing of different-sized particles. A comparison of self-assembly using soft- and hard-magnetic templates is also presented, the former being magnetized in a uniform field. This analysis shows that soft-magnetic templates enable an order-of-magnitude more rapid assembly and much higher spatial resolution in particle placement than their hard-magnetic counterparts. The self-assembly method discussed is versatile and broadly applies to arbitrary template geometries and multilayered and multifunctional mono- and polydisperse core-shell particles that have at least one magnetic component. As such, the method holds potential for the bottom-up fabrication of functional nanostructured materials for a broad range of applications. This work provides unprecedented insight into the assembly

  3. Effects of core-to-dentin thickness ratio on the biaxial flexural strength, reliability, and fracture mode of bilayered materials of zirconia core (Y-TZP) and veneer indirect composite resins.

    Science.gov (United States)

    Su, Naichuan; Liao, Yunmao; Zhang, Hai; Yue, Li; Lu, Xiaowen; Shen, Jiefei; Wang, Hang

    2017-01-01

    Indirect composite resins (ICR) are promising alternatives as veneering materials for zirconia frameworks. The effects of core-to-dentin thickness ratio (C/Dtr) on the mechanical property of bilayered veneer ICR/yttria-tetragonal zirconia polycrystalline (Y-TZP) core disks have not been previously studied. The purpose of this in vitro study was to assess the effects of C/Dtr on the biaxial flexural strength, reliability, and fracture mode of bilayered veneer ICR/ Y-TZP core disks. A total of 180 bilayered 0.6-mm-thick composite resin disks in core material and C/Dtr of 2:1, 1:1, and 1:2 were tested with either core material placed up or placed down for piston-on-3-ball biaxial flexural strength. The mean biaxial flexural strength, Weibull modulus, and fracture mode were measured to evaluate the variation trend of the biaxial flexural strength, reliability, and fracture mode of the bilayered disks with various C/Dtr. One-way analysis of variance (ANOVA) and chi-square tests were used to evaluate the variation tendency of fracture mode with the C/Dtr or material placed down during testing (α=.05). Light microscopy was used to identify the fracture mode. The mean biaxial flexural strength and reliability improved with the increase in C/Dtr when specimens were tested with the core material either up and down, and depended on the materials that were placed down during testing. The rates of delamination, Hertzian cone cracks, subcritical radial cracks, and number of fracture fragments partially depended on the C/Dtr and the materials that were placed down during testing. The biaxial flexural strength, reliability, and fracture mode in bilayered structures of Y-TZP core and veneer ICR depend on both the C/Dtr and the material that was placed down during testing. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  4. ROP MATHEMATICAL MODEL OF ROTARY-ULTRASONIC CORE DRILLING OF BRITTLE MATERIAL

    Directory of Open Access Journals (Sweden)

    Mera Fayez Horne

    2017-03-01

    Full Text Available The results from the Phoenix mission led scientists to believe it is possible that primitive life exists below the Martian surface. Therefore, drilling in Martian soil in search for organisms is the next logical step. Drilling on Mars is a major engineering challenge due to the drilling depth requirement and extreme environment condition. Mars lacks a thick atmosphere and a continuous magnetic field that shield the planet’s surface from solar radiation and solar flares. As a result, the Martian surface is sterile and if life ever existed, it must be found below the surface. NASA’s Mars Exploration Payload Advisory Group proposed that drilling should be considered as a priority investigation on Mars in an effort of finding evidence of extinct or extant life. The results from the Curiosity mission suggested drilling six meters deep in the red planet in search for life. Excavation tools deployed to Mars so far have been able to drill to a maximum depth of 6.5 cm. Thus, the drilling capabilities need to be increased by a factor of approximately 100 to achieve the goal of drilling six meters deep. This requirement puts a demand on developing new and more effective technologies to reach this goal. Previous research shows evidence of a promising drilling mechanism in rotary-ultrasonic for what it offers in terms of high surface quality, faster rate of penetration and higher material removal rate. This research addresses the need to understand the mechanics of the drill bit tip and rock interface in rotary-ultrasonic drilling performance of one drill bit at a time drilling in three types of rocks that vary in strength. A mathematical model identifying all contributing independent parameters, such as drill bit design parameters, drilling process parameters, ultrasonic wave amplitude and rocks’ material properties, that have effect on rate of penetration is developed. Analytical and experimental results under ambient condition are presented to show

  5. Synthesis and Performance of Highly Stable Star-Shaped Polyaniline Electrochromic Materials with Triphenylamine Core

    Science.gov (United States)

    Xiong, Shanxin; Li, Shuaishuai; Zhang, Xiangkai; Wang, Ru; Zhang, Runlan; Wang, Xiaoqin; Wu, Bohua; Gong, Ming; Chu, Jia

    2018-02-01

    The molecular architecture of conducting polymers has a significant impact on their conjugated structure and electrochemical properties. We have investigated the influence of star-shaped structure on the electrochemical and electrochromic properties of polyaniline (PANI). Star-shaped PANI (SPANI) was prepared by copolymerization of aniline with triphenylamine (TPA) using an emulsion polymerization method. With addition of less than 4.0 mol.% TPA, the resulting SPANI exhibited good solubility in xylene with dodecylbenzenesulfonic acid (DBSA) as doping acid. The structure and thermal stability of the SPANI were characterized using Fourier-transform infrared spectroscopy, Raman spectroscopy, and thermogravimetric analysis, and the electrochemical behavior was analyzed by cyclic voltammetry (CV). The electrochromic properties of SPANI were tested using an electrochemical workstation combined with an ultraviolet-visible (UV-Vis) spectrometer. The results show that, with increasing TPA loading, the thermal stability of SPANI increased. With addition of 4.0 mol.% TPA, the weight loss of SPANI was 36.9% at 700°C, much lower than the value of 71.2% for PANI at the same temperature. The low oxidation potential and large enclosed area of the CV curves indicate that SPANI possesses higher electrochemical activity than PANI. Enhanced electrochromic properties including higher optical contrast and better electrochromic stability of SPANI were also obtained. SPANI with 1.6 mol.% TPA loading exhibited the highest optical contrast of 0.71, higher than the values of 0.58 for PANI, 0.66 for SPANI-0.4%, or 0.63 for SPANI-4.0%. Overdosing of TPA resulted in slow switching speed due to slow ion transport in short branched chains of star-shaped PANI electrochromic material. Long-term stability testing confirmed that all the SPANI-based devices exhibited better stability than the PANI-based device.

  6. Fast assessment of retrospective dosimetry using the SAAD–POSL method with core disc samples from building materials

    International Nuclear Information System (INIS)

    Kim, M.J.; Lee, Y.J.; Lee, J.I.; Kim, J.L.; Hong, D.G.

    2014-01-01

    To establish a fast assessment method of accidental dose, core disc samples were extracted from a heated red brick, roof tile, ceramic tile, and toilet porcelain, which are commonly used building materials. We examined the physical characteristics of pulsed optically stimulated luminescence (POSL) signals from these samples, and tested the reliability of the single aliquot additive dose (SAAD)-POSL method over a range of 7 Gy. In addition, when the SAAD-POSL method was applied, the minimum detectable dose (MDD) was as low as 0.01 Gy for the heated red brick, and the calculation time for an equivalent dose was as short as 2 h. This result indicates that the SAAD-POSL method is more effective as a fast assessment method of accidental dose than the SAR-OSL method. - Highlights: • SAAD-POSL method was developed for an urgent accidental dosimetry. • For building materials, the MDD of this method was very low as 0.01 Gy. • The determination time for an equivalent dose was very short within 2 h

  7. [Determination of high temperature compressive strength and refractory degree of die material compatible with slip casting core of sintered titanium powder].

    Science.gov (United States)

    Kuang, X; Liao, Y; Chao, Y; Meng, Y

    1999-05-01

    The refractory die is the precondition for developing slip casting core of sintered powder. This study is to determine the high temperature properties of the refractory die material compatible with slip casting core. To prepare three cylindrical specimens (phi 10 x 15 mm) and determine their compressive strength at 1000 degrees C: to make four specimens in flat-topped cone for determining the practical refractory degree by decreasing the pressing temperatures in a sequence of 1420, 1400, 1350 and 1100 degrees C. The compressive strength of this material was 17.8 MPa at 1000 degrees C. Its practical refractory degree was higher than 1100 degrees C. The high temperature properties of the refractory die material that we developed meet the demand of slip casting core of sintered powder.

  8. Characterization of a Porous Carbon Material Functionalized with Cobalt-Oxide/Cobalt Core-Shell Nanoparticles for Lithium Ion Battery Electrodes

    KAUST Repository

    Anjum, Dalaver H.

    2016-04-18

    A nanoporous carbon (C) material, functionalized with Cobalt-Oxide/Cobalt (CoO/Co) core-shell nanoparticles (NPs), was structurally and chemically characterized with transmission electron microcopy (TEM) while its electrochemical response for Lithium ion battery (LIB) applications was evaluated as well. The results herein show that the nanoporous C material was uniformly functionalized with the CoO/Co core-shell NPs. Further the NPs were crystalline with fcc-Type lattice on the Co2+ oxide shell and hcp-Type core of metallic Co0. The electrochemical study was carried out by using galvanostatic charge/discharge cycling at a current density of 1000 mA g-1. The potential of this hybrid material for LIB applications was confirmed and it is attributed to the successful dispersion of the Co2+/ Co0 NPs in the C support.

  9. Fractographic study of the behavior of different ceramic veneers on full coverage crowns in relation to supporting core materials

    OpenAIRE

    Farga-Niñoles, Ignacio; Agustín-Panadero, Rubén; Román-Rodriguez, Juan L.; Solá-Ruíz, María F.; Granell-Ruíz, María; Fons-Font, Antonio

    2013-01-01

    Objectives: To observe porcelain veneer behavior of zirconia and metal-ceramic full coverage crowns when subjected to compression testing, comparing zirconia cores to metal cores. Study Design: The porcelain fracture surfaces of 120 full coverage crowns (60 with a metal core and 60 with a zirconia core) subjected to static load (compression) testing were analyzed. Image analysis was performed using macroscopic processing with 8x and 12x enlargement. Five samples from each group were prepared ...

  10. In vitro shear bond strength of Y-TZP ceramics to different core materials with the use of three primer/resin cement systems.

    Science.gov (United States)

    Al-Harbi, Fahad A; Ayad, Neveen M; Khan, Zahid A; Mahrous, Amr A; Morgano, Steven M

    2016-01-01

    Durability of the bond between different core materials and zirconia retainers is an important predictor of the success of a dental prosthesis. Nevertheless, because of its polycrystalline structure, zirconia cannot be etched and bonded to a conventional resin cement. The purpose of this in vitro study was to compare the effects of 3 metal primer/resin cement systems on the shear bond strength (SBS) of 3 core materials bonded to yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) ceramic retainers. Zirconia ceramic (Cercon) disks (5×3 mm) were airborne-particle abraded, rinsed, and air-dried. Disk-shaped core specimens (7×7 mm) that were prepared of composite resin, Ni-Cr, and zirconia were bonded to the zirconia ceramic disks by using one of 3 metal primer/cement systems: (Z-Prime Plus/BisCem, Zirconia Primer/Multilink Automix, or Clearfil Ceramic Primer/Clearfil SA). SBS was tested in a universal testing machine. Stereomicroscopy was used to evaluate the failure mode of debonded specimens. Data were analyzed using 2-way ANOVA and post hoc analysis using the Scheffe procedure (α=.05). Clearfil SA/Clearfil Ceramic Primer system with an Ni-Cr core yielded the highest SBS value (19.03 MPa), whereas the lowest SBS value was obtained when Multilink Automix/Zirconia Primer system was used with the zirconia core group (4.09 MPa). Differences in mean SBS values among the cement/primer groups were statistically significant, except for Clearfil SA and BisCem with both composite resin and zirconia cores. Differences in mean SBS values among the core subgroups were not statistically significant, except for zirconia core with BisCem, Multilink, and Clearfil SA. The predominant failure mode was adhesive, except for Clearfil SA and BisCem luting agents with composite resin cores, which displayed cohesive failure, and Multilink Automix with a composite resin, core as well as Clearfil SA with Ni-Cr cores, where the debonded specimens of each group displayed a mixed

  11. The effect of core material, veneering porcelain, and fabrication technique on the biaxial flexural strength and weibull analysis of selected dental ceramics.

    Science.gov (United States)

    Lin, Wei-Shao; Ercoli, Carlo; Feng, Changyong; Morton, Dean

    2012-07-01

    The objective of this study was to compare the effect of veneering porcelain (monolithic or bilayer specimens) and core fabrication technique (heat-pressed or CAD/CAM) on the biaxial flexural strength and Weibull modulus of leucite-reinforced and lithium-disilicate glass ceramics. In addition, the effect of veneering technique (heat-pressed or powder/liquid layering) for zirconia ceramics on the biaxial flexural strength and Weibull modulus was studied. Five ceramic core materials (IPS Empress Esthetic, IPS Empress CAD, IPS e.max Press, IPS e.max CAD, IPS e.max ZirCAD) and three corresponding veneering porcelains (IPS Empress Esthetic Veneer, IPS e.max Ceram, IPS e.max ZirPress) were selected for this study. Each core material group contained three subgroups based on the core material thickness and the presence of corresponding veneering porcelain as follows: 1.5 mm core material only (subgroup 1.5C), 0.8 mm core material only (subgroup 0.8C), and 1.5 mm core/veneer group: 0.8 mm core with 0.7 mm corresponding veneering porcelain with a powder/liquid layering technique (subgroup 0.8C-0.7VL). The ZirCAD group had one additional 1.5 mm core/veneer subgroup with 0.7 mm heat-pressed veneering porcelain (subgroup 0.8C-0.7VP). The biaxial flexural strengths were compared for each subgroup (n = 10) according to ISO standard 6872:2008 with ANOVA and Tukey's post hoc multiple comparison test (p≤ 0.05). The reliability of strength was analyzed with the Weibull distribution. For all core materials, the 1.5 mm core/veneer subgroups (0.8C-0.7VL, 0.8C-0.7VP) had significantly lower mean biaxial flexural strengths (p veneered ZirCAD groups showed greater flexural strength than the monolithic Empress and e.max groups, regardless of core thickness and fabrication techniques. Comparing fabrication techniques, Empress Esthetic/CAD, e.max Press/CAD had similar biaxial flexural strength (p= 0.28 for Empress pair; p= 0.87 for e.max pair); however, e.max CAD/Press groups had

  12. Fabrication of Fe{sub 3}O{sub 4}@CuO core-shell from MOF based materials and its antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Rajabi, S.K. [Department of Chemistry, University of Guilan, University Campus 2, Rasht (Iran, Islamic Republic of); Sohrabnezhad, Sh., E-mail: sohrabnezhad@guilan.ac.ir [Department of Chemistry, Faculty of Science, University of Guilan, P.O. Box 1914, Rasht (Iran, Islamic Republic of); Ghafourian, S. [Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam (Iran, Islamic Republic of)

    2016-12-15

    Magnetic Fe{sub 3}O{sub 4}@CuO nanocomposite with a core/shell structure was successfully synthesized via direct calcinations of magnetic Fe{sub 3}O{sub 4}@HKUST-1 in air atmosphere. The morphology, structure, magnetic and porous properties of the as-synthesized nano composites were characterized by using scanning electron microscope (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (PXRD), and vibration sample magnetometer (VSM). The results showed that the nanocomposite material included a Fe{sub 3}O{sub 4} core and a CuO shell. The Fe{sub 3}O{sub 4}@CuO core-shell can be separated easily from the medium by a small magnet. The antibacterial activity of Fe{sub 3}O{sub 4}-CuO core-shell was investigated against gram-positive and gram-negative bacteria. A new mechanism was proposed for inactivation of bacteria over the prepared sample. It was demonstrated that the core-shell exhibit recyclable antibacterial activity, acting as an ideal long-acting antibacterial agent. - Graphical abstract: Fe{sub 3}O{sub 4}@CuO core-shell release of copper ions. These Cu{sup 2+} ions were responsible for the exhibited antibacterial activity. - Highlights: • The Fe{sub 3}O{sub 4}@CuO core-shell was prepared by MOF method. • This is the first study of antibacterial activity of core-shell consist of CuO and Fe{sub 3}O{sub 4}. • The core-shell can be reused effectively. • Core-shell was separated from the reaction solution by external magnetic field.

  13. PBDOWN - a computer code for simulating core material discharge and thermal to mechanical energy conversion in LMFBR hypothetical accidents

    International Nuclear Information System (INIS)

    Royl, P.

    1981-01-01

    PBDOWN is a computer code that simulates the blowdown of confined boiling materials ('pools') into a colder upper coolant plenum as time dependent ejection and expansion with consideration of a few selected exchange processes. Its application is restricted to situations resulting from hypothetical loss of flow (LOF) accidents in LMFBR's, where enough voiding has occured, that in core sodium vapor pressures become negligible. PBDOWN considers one working fluid for the discharge process (either fuel or steel) and a maximum of two working fluids (either fuel and sodium or steel and sodium) for the expansion process in the upper coolant plenum. Entrainment of sodium at the accelerated bubble liquid interfaces is mechanistically calculated by a Taylor instability entrainment model. Simulation of a hemispherical expansion form together with this mechanistic entrainment model gives a new integrated calculation of the time dependent sodium mass in the bubble. The paper summarizes the basic equations and assumptions of this computer model. Sample results compare different heat transfer and Na entrainment models during steel and fuel driven discharge processes. Mechanistic sodium entrainment simulation for SNR-type reactors coupled with a realistic heat transfer model is shown to reduce the integral mechanical work potential by a factor of 1.3 to 2.0 over the isentropic energy of the discharge working fluids. (orig.)

  14. Core-Shell Al-Polytetrafluoroethylene (PTFE) Configurations to Enhance Reaction Kinetics and Energy Performance for Nanoenergetic Materials.

    Science.gov (United States)

    Wang, Jun; Qiao, Zhiqiang; Yang, Yuntao; Shen, Jinpeng; Long, Zhang; Li, Zhaoqian; Cui, Xudong; Yang, Guangcheng

    2016-01-04

    The energy performance of solid energetic materials (Al, Mg, etc.) is typically restricted by a natural passivation layer and the diffusion-limited kinetics between the oxidizer and the metal. In this work, we use polytetrafluoroethylene (PTFE) as the fluorine carrier and the shielding layer to construct a new type of nano-Al based fuels. The PTFE shell not only prevents nano-Al layers from oxidation, but also assists in enhancing the reaction kinetics, greatly improving the stability and reactivity of fuels. An in situ chemical vapor deposition combined with the electrical explosion of wires (EEW) method is used to fabricate core-shell nanostructures. Studies show that by controlling the stoichiometric ratio of the precursors, the morphology of the PTFE shell and the energy performance can be easily tuned. The resultant composites exhibit superior energy output characters than that of their physically mixed Al/PTFE counterparts. This synthetic strategy might provide a general approach to prepare other high-energy fuels (Mg, Si). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. New measurement system for on line in core high-energy neutron flux monitoring in materials testing reactor conditions.

    Science.gov (United States)

    Geslot, B; Vermeeren, L; Filliatre, P; Lopez, A Legrand; Barbot, L; Jammes, C; Bréaud, S; Oriol, L; Villard, J-F

    2011-03-01

    Flux monitoring is of great interest for experimental studies in material testing reactors. Nowadays, only the thermal neutron flux can be monitored on line, e.g., using fission chambers or self-powered neutron detectors. In the framework of the Joint Instrumentation Laboratory between SCK-CEN and CEA, we have developed a fast neutron detector system (FNDS) capable of measuring on line the local high-energy neutron flux in fission reactor core and reflector locations. FNDS is based on fission chambers measurements in Campbelling mode. The system consists of two detectors, one detector being mainly sensitive to fast neutrons and the other one to thermal neutrons. On line data processing uses the CEA depletion code DARWIN in order to disentangle fast and thermal neutrons components, taking into account the isotopic evolution of the fissile deposit. The first results of FNDS experimental test in the BR2 reactor are presented in this paper. Several fission chambers have been irradiated up to a fluence of about 7 × 10(20) n∕cm(2). A good agreement (less than 10% discrepancy) was observed between FNDS fast flux estimation and reference flux measurement.

  16. Source contributions to radiocesium contaminated particulate matter deposited in a reservoir after the Fukushima accident

    Science.gov (United States)

    Laceby, J. Patrick; Huon, Sylvain; Hayashi, Seiji; Onda, Yuichi; Evrard, Olivier

    2017-04-01

    The Fukushima nuclear accident resulted in the deposition of radiocesium over forested and rural landscapes northwest of the power plant. Although there have been several investigations into the dynamics of contaminated river sediment, less attention has been paid to the sources of deposited particulate matter in dams and reservoirs. In the Fukushima Prefecture, there are 10 significant dams and over a 1,000 reservoirs for both agricultural and surface water management. These reservoirs may have trapped a significant volume of radiocesium contaminated sediment, and understanding the sources of this material is important for the ongoing management of contamination in the region. Accordingly, the source of contaminated particulate matter (i.e. cultivated, forest and subsoils) deposited in the Mano Dam reservoir, Japan, was investigated with the analyses and modelling of carbon and nitrogen stable isotope ratios, total organic carbon and total nitrogen concentrations. Four sediment cores with lengths ranging from 29-41 cm were sampled in the Mano Dam, approximately 40 km northwest of the FDNPP. Source samples were taken from 46 forest soils, 28 cultivated soils and 25 subsoils in the region. Carbon-nitrogen parameters were analysed on all samples and a concentration-dependent distribution modelling approach was used to apportion source contributions. Three of the four cores sampled in the Mano Dam reservoir had distinct radiocesium peaks representative of the initial post-accident wash-off phase. Cultivated sources were responsible for 48% (SD 7%) of the deposited fine particulate matter in the three cores with the radiocesium peaks, whereas forests were modelled to contribute 27% (SD 6%) and subsoil sources 25% (SD 4%). Ongoing decontamination of cultivated sources in the Fukushima region should result in a decrease of contaminated matter deposited in reservoirs. More research is required to understand the potential ongoing source contributions from forested

  17. Material properties of oxide dispersion strengthened (ODS) ferritic steels for core materials of FBR. Mechanical strength properties of sodium exposed and Nickel diffused materials. Interim report

    International Nuclear Information System (INIS)

    Kato, Shoichi; Yoshida, Eiichi

    2004-02-01

    An oxide dispersion strengthened (ODS) ferritic steel have excellent resistance to swelling and superior creep strength, they are expected to be used as a long-life cladding material in future advanced fast reactor. In this study, sodium environmental effects on the ODS steel developed by JNC were clarified through tensile test after sodium exposure for maximum 10,000hrs and creep-rupture test in sodium at elevated temperature. The exposure to sodium was conducted using a sodium test loop constituted by austenitic steels. For the conditions of sodium exposure test, the sodium temperatures were 923 K and 973 K, the oxygen concentration in sodium was below 2ppm and sodium flow rate on the surface of specimen was less than 1x10 -4 m/s. Further the specimen with the nickel diffused was prepared, which is simulate to nickel diffusing through sodium from the surface of structural stainless steels. The main results obtained were as follows; (1) The results showed excellent sodium-resistance up to a high temperature of about 973 K in stagnant sodium conditions, and its considered that the effects of sodium environment of tensile properties were negligible. In case of stagnant sodium condition, creep-rupture strength in sodium was equal to the in argon gas, and no sodium environmental effect was observed. The same is true for the creep-rupture ductility. (2) The tensile properties of nickel diffused test specimens at high temperatures simulating microstructure change were equal to that of the thermal aging process specimens. These tensile tests suggest that sodium environmental effects can be ignored. However, the effect of nickel diffusion on creep strength are not clear at present and experimental investigation are being conducted. (3) The coefficient of nickel diffusion in the ODS steel can be estimated based on the results of nickel concentration measurement. This value is larger than that of the diffusion coefficient for typical α-Fe steel at temperature below 973 K

  18. Influence of material non-linearity on the thermo-mechanical response of polymer foam cored sandwich structures - FE modelling and preliminary experiemntal results

    DEFF Research Database (Denmark)

    Palleti, Hara Naga Krishna Teja; Thomsen, Ole Thybo; Fruehmann, Richard.K

    In this paper, the polymer foam cored sandwich structures with fibre reinforced composite face sheets will be analyzed using the commercial FE code ABAQUS/Standard® incorporating the material and geometrical non-linearity. Large deformations are allowed which attributes geometric non linearity...

  19. Improved efficiency of reversed-phase carbon/nanodiamond/polymer core-shell particles for HPLC using carbonized poly(divinylbenzene) microspheres as the core materials.

    Science.gov (United States)

    Hung, Chuan-Hsi; Wiest, Landon A; Singh, Bhupinder; Diwan, Anubhav; Valentim, Michael J C; Christensen, James M; Davis, Robert C; Miles, Andrew J; Jensen, David S; Vail, Michael A; Dadson, Andrew E; Linford, Matthew R

    2013-12-01

    Here, we report efficiencies up to 112,000 plates per meter (a reduced plate height, h, of 2.22) for RP, carbon/nanodiamond/aminopolymer particles using conventional injection conditions in HPLC. This efficiency greatly exceeds our best previously reported value of 71,000 N/m (h = 3.52). The carbon cores used in this study were derived from carbonized poly(divinylbenzene) spheres that were either made in-house by a two-step polymerization procedure or obtained commercially. The resulting particles showed good uniformity and were oxidized in nitric acid to increase their dispersability. X-ray photoelectron spectroscopy confirms particle oxidation and subsequent aminopolymer deposition. Layer-by-layer (LbL) growth of poly(allyamine) and nanodiamond was demonstrated to produce core-shell particles. After LbL growth, the particles were functionalized, sieved, and packed into columns. The column functionalization and packing were reproducible. Van Deemter curves indicated that the commercially obtained poly(divinylbenzene) spheres outperformed those synthesized in our laboratory. The columns appear to be stable at 120°C in a pH 11.3 mobile phase. Longer columns (2.1 × 50 mm) than previously reported were packed. Four essential oils were separated by gradient elution. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Reconstructing Watershed History from Reservoir Stratigraphy: Englebright Lake, Yuba River, Northern California

    Science.gov (United States)

    Snyder, N. P.; Alpers, C. N.; Childs, J. R.; Curtis, J. A.; Flint, L. E.; Holmes, C. W.; Rubin, D. M.; Wright, S. A.

    2004-12-01

    Reservoirs provide the opportunity to study fluvial processes and rates in a controlled setting because they are effective traps of sediment and are often well monitored. An extensive sediment coring and sampling campaign was done in Englebright Lake on the Yuba River in northern California as part of a fish-habitat restoration study. The Yuba watershed (particularly the southern part) was the site of intensive hydraulic gold mining in the 19th and early 20th century, and Englebright Dam was built in 1940 to trap mining debris. Results of a bathymetric survey in 2001 indicate that the reservoir was 26% full (22x106 m3 of material). The physical properties of the entire deposit were extrapolated from ˜300 m of cores collected at 7 sites along the longitudinal axis of the reservoir in 2002. The mass of the deposit is 26x106 metric tons, of which 3.2% is organic. The sediment is ˜65% sand and gravel, and distinct layers of differing grain size (sand-gravel, silt-clay, organics) are well preserved in the cores. The depositional chronology of the reservoir was established using 137Cs analysis and the relations between the cored stratigraphy and the hydrologic and impoundment history of the watershed. Deposits from three major flood events (1955, 1964, 1997; each with discharge >3,400 m3/s) were identified in the stratigraphy of most of the coring sites. Observations of recent (post-1997) depositional patterns are guiding the development of a conceptual model of reservoir-sedimentation processes during floods, drawdowns, and intraflood periods. Enlargement of an upstream dam on the North Yuba River in 1970 caused a decrease in flood frequency in the Yuba River and changed management of Englebright Lake (ending annual drawdowns). A relict topset-foreset-bottomset sequence observed in the cored stratigraphy is interpreted to correlate with this change in watershed management; a second deltaic sequence was deposited on top of the first after 1970. Post-1970 average annual

  1. Influence of core thickness and artificial aging on the biaxial flexural strength of different all-ceramic materials: An in-vitro study.

    Science.gov (United States)

    Dikicier, Sibel; Ayyildiz, Simel; Ozen, Julide; Sipahi, Cumhur

    2017-05-31

    The purpose of this study was to investigate the flexural strength of all-ceramics with varying core thicknesses submitted to aging. In-Ceram Alumina (IC), IPS e.max Press (EM) and Katana (K) (n=40), were selected. Each group contained two core groups based on the core thickness as follows: IC/0.5, IC/0.8, EM/0.5, EM/0.8, K/0.5 and K/0.8 mm in thickness (n=20 each). Ten specimens from each group were subjected to aging and all specimens were tested for strength in a testing machine either with or without being subjected aging. The mean strength of the K were higher (873.05 MPa) than that of the IC (548.28 MPa) and EM (374.32 MPa) regardless of core thickness. Strength values increased with increasing core thickness for all IC, EM and K regardless of aging. Results of this study concluded that strength was not significantly affected by aging. Different core thicknesses affected strength of the all-ceramic materials tested (p<0.05).

  2. EXPLOITATION AND OPTIMIZATION OF RESERVOIR PERFORMANCE IN HUNTON FORMATION, OKLAHOMA

    Energy Technology Data Exchange (ETDEWEB)

    Mohan Kelkar

    2004-10-01

    West Carney field--one of the newest fields discovered in Oklahoma--exhibits many unique production characteristics. These characteristics include: (1) decreasing water-oil ratio; (2) decreasing gas-oil ratio followed by an increase; (3) poor prediction capability of the reserves based on the log data; and (4) low geological connectivity but high hydrodynamic connectivity. The purpose of this investigation is to understand the principal mechanisms affecting the production, and propose methods by which we can extend the phenomenon to other fields with similar characteristics. In our experimental investigation section, we present the data on surfactant injection in near well bore region. We demonstrate that by injecting the surfactant, the relative permeability of water could be decreased, and that of gas could be increased. This should result in improved gas recovery from the reservoir. Our geological analysis of the reservoir develops the detailed stratigraphic description of the reservoir. Two new stratigraphic units, previously unrecognized, are identified. Additional lithofacies are recognized in new core descriptions. Our engineering analysis has determined that well density is an important parameter in optimally producing Hunton reservoirs. It appears that 160 acre is an optimal spacing. The reservoir pressure appears to decline over time; however, recovery per well is only weakly influenced by the pressure. This indicates that additional opportunity to drill wells exists in relatively depleted fields. A simple material balance technique is developed to validate the recovery of gas, oil and water. This technique can be used to further extrapolate recoveries from other fields with similar field characteristics.

  3. Effect of the shell material and confinement type on the conversion efficiency of core/shell quantum dot nanocrystal solar cells.

    Science.gov (United States)

    Sahin, Mehmet

    2018-05-23

    In this study, the effects of the shell material and confinement type on the conversion efficiency of core/shell quantum dot nanocrystal (QDNC) solar cells have been investigated in detail. For this purpose, the conventional, i.e. original, detailed balance model, developed by Shockley and Queisser to calculate an upper limit for the conversion efficiency of silicon p-n junction solar cells, is modified in a simple and effective way to calculate the conversion efficiency of core/shell QDNC solar cells. Since the existing model relies on the gap energy ([Formula: see text]) of the solar cell, it does not make an estimation about the effect of QDNC materials on the efficiency of the solar cells, and gives the same efficiency values for several QDNC solar cells with the same [Formula: see text]. The proposed modification, however, estimates a conversion efficiency in relation to the material properties and also the confinement type of the QDNCs. The results of the modified model show that, in contrast to the original one, the conversion efficiencies of different QDNC solar cells, even if they have the same [Formula: see text], become different depending upon the confinement type and shell material of the core/shell QDNCs, and this is crucial in the design and fabrication of the new generation solar cells to predict the confinement type and also appropriate QDNC materials for better efficiency.

  4. Thermally stable aromatic amine derivative with symmetrically substituted double spirobifluorene core as a hole transport material for green phosphorescent organic light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yong Joo; Lee, Jun Yeob, E-mail: leej17@dankook.ac.kr

    2012-11-01

    A thermally stable aromatic amine derivative with a symmetrically substituted double spirobifluorene core was synthesized as a hole transport material for green phosphorescent organic light-emitting diodes. A high glass transition temperature of 142 Degree-Sign C was obtained and a film morphology of the hole transport material was kept stable up to 120 Degree-Sign C. The hole transport material showed a high triplet energy of 2.53 eV and a quantum efficiency of 17.4% in green phosphorescent organic light-emitting diodes. - Highlights: Black-Right-Pointing-Pointer Synthesis of symmetrically substituted double spirobifluorene core Black-Right-Pointing-Pointer Stable film morphology up to 120 Degree-Sign C Black-Right-Pointing-Pointer High quantum efficiency in green phosphorescent organic light emitting diode.

  5. One-step synthesis of metal@titania core-shell materials for visible-light photocatalysis and catalytic reduction reaction.

    Science.gov (United States)

    Xiong, Zhigang; Zhang, Luhong; Zhao, Xiu Song

    2014-11-03

    Metal@TiO2 composites with a core-shell structure possess multifunctional properties. The demonstrated protocols for synthesizing such materials involve multiple steps, requiring precise control over the particle uniformity of the core and shell thickness, as well as complex surface modification. A simple approach to synthesizing metal@TiO2 hybrid nanostructures remains a great challenge. Herein, we report on a one-step method for the preparation of metal@TiO2 core-shell nanospheres, which exhibited excellent performance in photocatalytic degradation of recalcitrant organic pollutants under visible light irradiation, and in catalytic reduction of nitrophenol in water. The simple method described here represents a sustainable approach to preparing core-shell materials at low cost, involving fewer chemicals, and requiring less energy, which will make a significant contribution toward large-scale synthesis of high-performance hybrid materials for photocatalytic applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Repairing rabbit radial defects by combining bone marrow stroma stem cells with bone scaffold material comprising a core-cladding structure.

    Science.gov (United States)

    Wu, H; Liu, G H; Wu, Q; Yu, B

    2015-10-05

    We prepared a bone scaffold material comprising a PLGA/β-TCP core and a Type I collagen cladding, and recombined it with bone marrow stroma stem cells (BMSCs) to evaluate its potential for use in bone tissue engineering by in vivo and in vitro experiments. PLGA/β-TCP without a cladding was used for comparison. The adherence rate of the BMSCs to the scaffold was determined by cell counting. Cell proliferation rate was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. The osteogenic capability was evaluated by alkaline phosphatase activity. The scaffold materials were recombined with the BMSCs and implanted into a large segmental rabbit radial defect model to evaluate defect repair. Osteogenesis was assessed in the scaffold materials by histological and double immunofluorescence labeling, etc. The adherence number, proliferation number, and alkaline phosphatase expression of the cells on the bone scaffold material with core-cladding structure were significantly higher than the corresponding values in the PLGA/β-TCP composite scaffold material (P structure completely degraded at the bone defect site and bone formation was completed. The rabbit large sentimental radial defect was successfully repaired. The degradation and osteogenesis rates matched well. The bone scaffold with core-cladding structure exhibited better osteogenic activity and capacity to repair a large segmental bone defect compared to the PLGA/β-TCP composite scaffold. The bone scaffold with core-cladding structure has excellent physical properties and biocompatibility. It is an ideal scaffold material for bone tissue engineering.

  7. Properties of polyurethane foam/coconut coir fiber as a core material and as a sandwich composites component

    International Nuclear Information System (INIS)

    Azmi, M A; Abdullah, H Z; Idris, M I

    2013-01-01

    This research focuses on the fabrication and characterization of sandwich composite panels using glass fiber composite skin and polyurethane foam reinforced coconut coir fiber core. The main objectives are to characterize the physical and mechanical properties and to elucidate the effect of coconut coir fibers in polyurethane foam cores and sandwich composite panels. Coconut coir fibers were used as reinforcement in polyurethane foams in which later were applied as the core in sandwich composites ranged from 5 wt% to 20 wt%. The physical and mechanical properties found to be significant at 5 wt% coconut coir fiber in polyurethane foam cores as well as in sandwich composites. It was found that composites properties serve better in sandwich composites construction

  8. Properties of polyurethane foam/coconut coir fiber as a core material and as a sandwich composites component

    Science.gov (United States)

    Azmi, M. A.; Abdullah, H. Z.; Idris, M. I.

    2013-12-01

    This research focuses on the fabrication and characterization of sandwich composite panels using glass fiber composite skin and polyurethane foam reinforced coconut coir fiber core. The main objectives are to characterize the physical and mechanical properties and to elucidate the effect of coconut coir fibers in polyurethane foam cores and sandwich composite panels. Coconut coir fibers were used as reinforcement in polyurethane foams in which later were applied as the core in sandwich composites ranged from 5 wt% to 20 wt%. The physical and mechanical properties found to be significant at 5 wt% coconut coir fiber in polyurethane foam cores as well as in sandwich composites. It was found that composites properties serve better in sandwich composites construction.

  9. Chemical gradients in sediment cores from an EPA reference site off the Farallon Islands - Assessing chemical indicators of dredged material disposal in the deep sea

    Science.gov (United States)

    Bothner, Michael H.; Gill, P.W.; Boothman, W.S.; Taylor, B.B.; Karl, Herman A.

    1998-01-01

    Heavy metal and organic contaminants have been determined in undisturbed sediment cores from the US Environmental Protection Agency reference site for dredged material on the continental slope off San Francisco. As expected, the concentrations are significantly lower than toxic effects guidelines, but concentrations of PCBs, PAHs, Hg, Pb, and Clostridium perfringens (a bacterium spore found in sewage) were nearly two or more times greater in the surface sediments than in intervals deeper in the cores. These observations indicate the usefulness of measuring concentration gradients in sediments at the San Francisco deep ocean disposal site (SF-DODS) where a thin (0.5 cm thick) layer of dredged material has been observed beyond the boundary. This thin layer has not been chemically characterized by the common practice of homogenizing over the top 10 cm. An estimated 300 million cubic yards of dredged material from San Francisco Bay are expected to be discharged at the SF-DODS site during the next 50 years. Detailed depth analysis of sediment cores would add significant new information about the fate and effects of dredged material in the deep sea.

  10. Reservoir effects in radiocarbon dating

    International Nuclear Information System (INIS)

    Head, M.J.

    1997-01-01

    Full text: The radiocarbon dating technique depends essentially on the assumption that atmospheric carbon dioxide containing the cosmogenic radioisotope 14 C enters into a state of equilibrium with all living material (plants and animals) as part of the terrestrial carbon cycle. Terrestrial reservoir effects occur when the atmospheric 14 C signal is diluted by local effects where systems depleted in 14 C mix with systems that are in equilibrium with the atmosphere. Naturally, this can occur with plant material growing close to an active volcano adding very old CO 2 to the atmosphere (the original 14 C has completely decayed). It can also occur in highly industrialised areas where fossil fuel derived CO 2 dilutes the atmospheric signal. A terrestrial reservoir effect can occur in the case of fresh water shells living in rivers or lakes where there is an input of ground water from springs or a raising of the water table. Soluble bicarbonate derived from the dissolution of very old limestone produces a 14 C dilution effect. Land snail shells and stream carbonate depositions (tufas and travertines) can be affected by a similar mechanism. Alternatively, in specific cases, these reservoir effects may not occur. This means that general interpretations assuming quantitative values for these terrestrial effects are not possible. Each microenvironment associated with samples being analysed needs to be evaluated independently. Similarly, the marine environment produces reservoir effects. With respect to marine shells and corals, the water depth at which carbonate growth occurs can significantly affect quantitative 14 C dilution, especially in areas where very old water is uplifted, mixing with top layers of water that undergo significant exchange with atmospheric CO 2 . Hence, generalisations with respect to the marine reservoir effect also pose problems. These can be exacerbated by the mixing of sea water with either terrestrial water in estuaries, or ground water where

  11. Smart Waterflooding in Carbonate Reservoirs

    DEFF Research Database (Denmark)

    Zahid, Adeel

    During the last decade, smart waterflooding has been developed into an emerging EOR technology both for carbonate and sandstone reservoirs that does not require toxic or expensive chemicals. Although it is widely accepted that different salinity brines may increase the oil recovery for carbonate...... reservoirs, understanding of the mechanism of this increase is still developing. To understand this smart waterflooding process, an extensive research has been carried out covering a broad range of disciplines within surface chemistry, thermodynamics of crude oil and brine, as well as their behavior...... that a heavy oil (that with a large fraction of heavy components) exhibited viscosity reduction in contact with brine, while a light crude oil exhibited emulsion formation. Most of reported high salinity waterflooding studies were carried out with outcrop chalk core plugs, and by performing spontaneous...

  12. Analysis of resin-dentin interface morphology and bond strength evaluation of core materials for one stage post-endodontic restorations.

    Directory of Open Access Journals (Sweden)

    Kerstin Bitter

    Full Text Available PURPOSE: Restoration of endodontically treated teeth using fiber posts in a one-stage procedure gains more popularity and aims to create a secondary monoblock. Data of detailed analyses of so called "post-and-core-systems" with respect to morphological characteristics of the resin-dentin interface in combination with bond strength measurements of fiber posts luted with these materials are scarce. The present study aimed to analyze four different post-and-core-systems with two different adhesive approaches (self-etch and etch-and-rinse. MATERIALS AND METHODS: Human anterior teeth (n = 80 were endodontically treated and post space preparations and post placement were performed using the following systems: Rebilda Post/Rebilda DC/Futurabond DC (Voco (RB, Luxapost/Luxacore Z/Luxabond Prebond and Luxabond A+B (DMG (LC, X Post/Core X Flow/XP Bond and Self Cure Activator (Dentsply DeTrey (CX, FRC Postec/MultiCore Flow/AdheSE DC (Ivoclar Vivadent (MC. Adhesive systems and core materials of 10 specimens per group were labeled using fluorescent dyes and resin-dentin interfaces were analyzed using Confocal Laser Scanning Microscopy (CLSM. Bond strengths were evaluated using a push-out test. Data were analyzed using repeated measurement ANOVA and following post-hoc test. RESULTS: CLSM analyses revealed significant differences between groups with respect to the factors hybrid layer thickness (p<0.0005 and number of resin tags (p = 0.02; ANOVA. Bond strength was significantly affected by core material (p = 0.001, location inside the root canal (p<0.0005 and incorporation of fluorescent dyes (p = 0.036; ANOVA. CX [7.7 (4.4 MPa] demonstrated significantly lower bond strength compared to LC [14.2 (8.7 MPa] and RB [13.3 (3.7 MPa] (p<0.05; Tukey HSD but did not differ significantly from MC [11.5 (3.5 MPa]. CONCLUSION: It can be concluded that bond strengths inside the root canal were not affected by the adhesive approach of the post-and-core-system. All systems

  13. Reservoir fisheries of Asia

    International Nuclear Information System (INIS)

    Silva, S.S. De.

    1990-01-01

    At a workshop on reservoir fisheries research, papers were presented on the limnology of reservoirs, the changes that follow impoundment, fisheries management and modelling, and fish culture techniques. Separate abstracts have been prepared for three papers from this workshop

  14. The effect of different soft segments on the formation and properties of binary core microencapsulated phase change materials with polyurea/polyurethane double shell.

    Science.gov (United States)

    Ma, Yanhong; Chu, Xiaodong; Tang, Guoyi; Yao, Youwei

    2013-02-15

    A series of polyurea/polyurethane microcapsules with butyl stearate and paraffin as binary core materials are successfully synthesized via interfacial polymerization method. The phase change temperature of these microencapsulated phase change materials (micro-PCMs) can be adjusted by regulating the composition of the binary core. SEM photographs show that these micro-PCMs have relatively spherical profiles and compact surfaces with diameter ranging from 5 to 15 μm. DSC results indicate that the binary core content in micro-PCMs is in a range of 45-60 wt%. Moreover, after being treated under 50°C for 7 days or subjected to thermal-cycling test for 500 times, the micro-PCMs keep good thermal performances and stabilities. Besides, these micro-PCMs show good thermal stability, and the degradation temperature differs from the different compositions of the binary core and molecular weight of the water-soluble monomers. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Large reservoirs: Chapter 17

    Science.gov (United States)

    Miranda, Leandro E.; Bettoli, Phillip William

    2010-01-01

    Large impoundments, defined as those with surface area of 200 ha or greater, are relatively new aquatic ecosystems in the global landscape. They represent important economic and environmental resources that provide benefits such as flood control, hydropower generation, navigation, water supply, commercial and recreational fisheries, and various other recreational and esthetic values. Construction of large impoundments was initially driven by economic needs, and ecological consequences received little consideration. However, in recent decades environmental issues have come to the forefront. In the closing decades of the 20th century societal values began to shift, especially in the developed world. Society is no longer willing to accept environmental damage as an inevitable consequence of human development, and it is now recognized that continued environmental degradation is unsustainable. Consequently, construction of large reservoirs has virtually stopped in North America. Nevertheless, in other parts of the world construction of large reservoirs continues. The emergence of systematic reservoir management in the early 20th century was guided by concepts developed for natural lakes (Miranda 1996). However, we now recognize that reservoirs are different and that reservoirs are not independent aquatic systems inasmuch as they are connected to upstream rivers and streams, the downstream river, other reservoirs in the basin, and the watershed. Reservoir systems exhibit longitudinal patterns both within and among reservoirs. Reservoirs are typically arranged sequentially as elements of an interacting network, filter water collected throughout their watersheds, and form a mosaic of predictable patterns. Traditional approaches to fisheries management such as stocking, regulating harvest, and in-lake habitat management do not always produce desired effects in reservoirs. As a result, managers may expend resources with little benefit to either fish or fishing. Some locally

  16. Petrophysical evaluation of reservoir sand bodies in Kwe Field ...

    African Journals Online (AJOL)

    Reservoir sand bodies in Kwe Field, coastal swamp depobelt, onshore eastern Niger Delta Basin were evaluated from a composite log suite comprising gamma ray, resistivity, density and neutron logs of five (5) wells with core photographs of one (1) reservoir of one well. The aim of the study was to evaluate the ...

  17. Reservoir Identification: Parameter Characterization or Feature Classification

    Science.gov (United States)

    Cao, J.

    2017-12-01

    The ultimate goal of oil and gas exploration is to find the oil or gas reservoirs with industrial mining value. Therefore, the core task of modern oil and gas exploration is to identify oil or gas reservoirs on the seismic profiles. Traditionally, the reservoir is identify by seismic inversion of a series of physical parameters such as porosity, saturation, permeability, formation pressure, and so on. Due to the heterogeneity of the geological medium, the approximation of the inversion model and the incompleteness and noisy of the data, the inversion results are highly uncertain and must be calibrated or corrected with well data. In areas where there are few wells or no well, reservoir identification based on seismic inversion is high-risk. Reservoir identification is essentially a classification issue. In the identification process, the underground rocks are divided into reservoirs with industrial mining value and host rocks with non-industrial mining value. In addition to the traditional physical parameters classification, the classification may be achieved using one or a few comprehensive features. By introducing the concept of seismic-print, we have developed a new reservoir identification method based on seismic-print analysis. Furthermore, we explore the possibility to use deep leaning to discover the seismic-print characteristics of oil and gas reservoirs. Preliminary experiments have shown that the deep learning of seismic data could distinguish gas reservoirs from host rocks. The combination of both seismic-print analysis and seismic deep learning is expected to be a more robust reservoir identification method. The work was supported by NSFC under grant No. 41430323 and No. U1562219, and the National Key Research and Development Program under Grant No. 2016YFC0601

  18. Fractographic study of the behavior of different ceramic veneers on full coverage crowns in relation to supporting core materials.

    Science.gov (United States)

    Farga-Niñoles, Ignacio; Agustín-Panadero, Rubén; Román-Rodriguez, Juan L; Solá-Ruíz, María F; Granell-Ruíz, María; Fons-Font, Antonio

    2013-12-01

    To observe porcelain veneer behavior of zirconia and metal-ceramic full coverage crowns when subjected to compression testing, comparing zirconia cores to metal cores. The porcelain fracture surfaces of 120 full coverage crowns (60 with a metal core and 60 with a zirconia core) subjected to static load (compression) testing were analyzed. Image analysis was performed using macroscopic processing with 8x and 12x enlargement. Five samples from each group were prepared and underwent scanning electron microscope (SEM) analysis in order to make a fractographic study of fracture propagation in the contact area and composition analysis in the most significant areas of the specimen. Statistically significant differences in fracture type (cohesive or adhesive) were found between the metal-ceramic and zirconia groups: the incidence of adhesive fracture was seen to be greater in metal-ceramic groups (92%) and cohesive fracture was more frequent in zirconium oxide groups (72%). The fracture propagation pattern was on the periphery of the contact area in the full coverage crown restorations selected for fractographic study. The greater frequency of cohesive fracture in restorations with zirconia cores indicates that their behavior is inadequate compared to metal-ceramic restorations and that further research is needed to improve their clinical performance. Key words:Zirconia, zirconium oxide, fractography, composition, porcelain veneers, fracture, cohesive, adhesive.

  19. The Synthesis of a Core-Shell Photocatalyst Material YF3:Ho3+@TiO2 and Investigation of Its Photocatalytic Properties

    Directory of Open Access Journals (Sweden)

    Xuan Xu

    2017-03-01

    Full Text Available In this paper, YF3:Ho3+@TiO2 core-shell nanomaterials were prepared by hydrolysis of tetra-n-butyl titanate (TBOT using polyvinylpyrrolidone K-30 (PVP as the coupling agent. Characterization methods including X-ray diffraction (XRD, transmission electron microscopy (TEM, energy-dispersive X-ray spectroscopy (EDS under TEM, X-ray photoelectron spectroscopy (XPS, fluorescence spectrometry, ultraviolet-visible diffuse reflectance spectroscopy, and electron spin resonance (ESR were used to characterize the properties and working mechanism of the prepared photocatalyst material. They indicated that the core phase YF3 nanoparticles were successfully coated with a TiO2 shell and the length of the composite was roughly 100 nm. The Ho3+ single-doped YF3:Ho3+@TiO2 displayed strong visible absorption peaks with wavelengths of 450, 537, and 644 nm, respectively. By selecting these three peaks as excitation wavelengths, we could observe 288 nm (5D4→5I8 ultraviolet emission, which confirmed that there was indeed an energy transfer from YF3:Ho3+ to anatase TiO2. In addition, this paper investigated the influences of different TBOT dosages on photocatalysis performance of the as-prepared photocatalyst material. Results showed that the YF3:Ho3+@TiO2 core-shell nanomaterial was an advanced visible-light-driven catalyst, which decomposed approximately 67% of rhodamine b (RhB and 34.6% of phenol after 10 h of photocatalysis reaction. Compared with the blank experiment, the photocatalysis efficiency was significantly improved. Finally, the visible-light-responsive photocatalytic mechanism of YF3:Ho3+@TiO2 core-shell materials and the influencing factors of photocatalytic degradation were investigated to study the apparent kinetics, which provides a theoretical basis for improving the structural design and functions of this new type of catalytic material.

  20. The effect of Er,Cr:YSGG laser application on the micropush-out bond strength of fiber posts to resin core material.

    Science.gov (United States)

    Kurtulmus-Yilmaz, Sevcan; Cengiz, Esra; Ozan, Oguz; Ramoglu, Serhat; Yilmaz, Hasan Guney

    2014-10-01

    The aim of this study was to compare the effects of erbium, chromium: yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser application to different surface treatments on the micropush-out bond strengths between glass and quartz fiber posts and composite resin core material. Different types of lasers have been used as an alternative to airborne particle abrasion and other surface treatment methods to enhance the bond strength of dental materials. However, there is no study regarding the use of Er,Cr:YSGG laser as a surface treatment method for fiber posts in order to improve the bond strength. Ninety-six quartz and 96 glass fiber posts with a coronal diameter of 1.8 mm were randomly divided into eight groups according the surface treatments applied. Gr 1 (control, no surface treatment), Gr 2 (sandblasting with 50 μm Al2O3), Gr 3 (9 % hydrofluoric acid for 1 min), Gr 4 (24% H2O2 for 1 min), Gr 5 (CH2Cl2 for 1 min), Gr 6 (1 W), Gr 7 (1.5 W), and Gr 8 (2 W) Er,Cr:YSGG laser irradiation. The resin core material was applied to each group, and then 1 mm thick discs (n=12) were obtained for the micropush-out test. Data were statistically analyzed. For the quartz fiber post group, all surface treatments showed significantly higher micropush-out bond strengths than the control group (pmaterial. However, the hydroflouric acid group showed the lowest bond strength values. The type of post and surface treatment might affect the bond strength between fiber posts and resin core material; 1 W and 1.5 W Er,Cr:YSGG laser application improved adhesion at the post/core interface.

  1. Reconstructing depositional processes and history from reservoir stratigraphy: Englebright Lake, Yuba River, northern California

    Science.gov (United States)

    Snyder, N.P.; Wright, S.A.; Alpers, Charles N.; Flint, L.E.; Holmes, C.W.; Rubin, D.M.

    2006-01-01

    Reservoirs provide the opportunity to link watershed history with its stratigraphic record. We analyze sediment cores from a northern California reservoir in the context of hydrologic history, watershed management, and depositional processes. Observations of recent depositional patterns, sediment-transport calculations, and 137CS geochronology support a conceptual model in which the reservoir delta progrades during floods of short duration (days) and is modified during prolonged (weeks to months) drawdowns that rework topset beds and transport sand from topsets to foresets. Sediment coarser than 0.25-0.5 mm. deposits in foresets and topsets, and finer material falls out of suspension as bottomset beds. Simple hydraulic calculations indicate that fine sand (0.063-0.5 mm) is transported into the distal bottomset area only during floods. The overall stratigraphy suggests that two phases of delta building occurred in the reservoir. The first, from dam construction in 1940 to 1970, was heavily influenced by annual, prolonged >20 m drawdowns of the water level. The second, built on top of the first, reflects sedimentation from 1970 to 2002 when the influence of drawdowns was less. Sedimentation rates in the central part of the reservoir have declined ???25% since 1970, likely reflecting a combination of fewer large floods, changes in watershed management, and winnowing of stored hydraulic mining sediment. Copyright 2006 by the American Geophysical Union.

  2. Physico-chemical characteristic of aluminum alloy castings manufactured with cores containing fly ash as a base material

    Directory of Open Access Journals (Sweden)

    A. Baliński

    2008-07-01

    Full Text Available Castings were poured from PA9 aluminum alloy. Cores in the form of standard cylindrical specimens were made from the core mixture based on fly ash of the identified chemical and granular composition. The binder for the fly ash-based core mixture was chemically modified, hydrated sodium silicate. From the ready test castings, specimens were cut out for metallographic examinations and evaluation of morphology in the examined microregions. The structure was examined under a NEOPHOT 32 metallographic microscope using metallographic polished sections etched and unetched. For the specimen surface morphology evaluation a STEREOSCAN 420 scanning electron microscope and SE1 detector were used. The X-ray microanalysis was made on an EDS LINK ISIS 300 microanalyser. The fly ash was observed to have no major effect on the structure and chemical composition of castings.

  3. Super-paramagnetic core-shell material with tunable magnetic behavior by regulating electron transfer efficiency and structure stability of the shell

    Directory of Open Access Journals (Sweden)

    Wenyan Zhang

    Full Text Available In this work, a spherical nano core-shell material was constructed by encapsulating Fe3O4 microsphere into conductive polymer-metal composite shell. The Fe3O4 microspheres were fabricated by assembling large amounts of Fe3O4 nano-crystals, which endowed the microspheres with super-paramagnetic property and high saturation magnetization. The polymer-metal composite shell was constructed by inserting Pt nano-particles (NPs into the conductive polymer polypyrrole (PPy. As size and dispersion of the Pt NPs has an important influence on their surface area and surface energy, it was effective to enlarge the interface area between PPy and Pt NPs, enhance the electron transfer efficiency of PPy/Pt composite shell, and reinforced the shell’s structural stability just by tuning the size and dispersion of Pt NPs. Moreover, core-shell structure of the materials made it convenient to investigate the PPy/Pt shell’s shielding effect on the Fe3O4 core’s magnetic response to external magnetic fields. It was found that the saturation magnetization of Fe3O4/PPy/Pt core-shell material could be reduced by 20.5% by regulating the conductivity of the PPy/Pt shell. Keywords: Super-paramagnetic, Conductivity, Magnetic shielding, Structural stability

  4. Stream, Lake, and Reservoir Management.

    Science.gov (United States)

    Dai, Jingjing; Mei, Ying; Chang, Chein-Chi

    2017-10-01

    This review on stream, lake, and reservoir management covers selected 2016 publications on the focus of the following sections: Stream, lake, and reservoir management • Water quality of stream, lake, and reservoirReservoir operations • Models of stream, lake, and reservoir • Remediation and restoration of stream, lake, and reservoir • Biota of stream, lake, and reservoir • Climate effect of stream, lake, and reservoir.

  5. Status of Wheeler Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    1990-09-01

    This is one in a series of status reports prepared by the Tennessee Valley Authority (TVA) for those interested in the conditions of TVA reservoirs. This overview of Wheeler Reservoir summarizes reservoir purposes and operation, reservoir and watershed characteristics, reservoir uses and use impairments, and water quality and aquatic biological conditions. The information presented here is from the most recent reports, publications, and original data available. If no recent data were available, historical data were summarized. If data were completely lacking, environmental professionals with special knowledge of the resource were interviewed. 12 refs., 2 figs.

  6. Core-shelled mesoporous CoFe2O4-SiO2 material with good adsorption and high-temperature magnetic recycling capabilities

    Science.gov (United States)

    Li, Zhi'ang; Wang, Jianlin; Liu, Min; Chen, Tong; Chen, Jifang; Ge, Wen; Fu, Zhengping; Peng, Ranran; Zhai, Xiaofang; Lu, Yalin

    2018-04-01

    Residues of organic dye in industrial effluents cause severe water system pollution. Although several methods, such as biodegradation and activated carbon adsorption, are available for treating these effluents before their discharge into waterbodies, secondary pollution by adsorbents and degrading products remains an issue. Therefore, new materials should be identified to solve this problem. In this work, CoFe2O4-SiO2 core-shell structures were synthesized using an improved Stöber method by coating mesoporous silica onto CoFe2O4 nanoparticles. The specific surface areas of the synthesized particles range from 30 m2/g to 150 m2/g and vary according to the dosage amount of tetraethoxysilane. Such core-shelled nanoparticles have the following advantages for treating industrial effluents mixed with dye: good adsorption capability, above-room-temperature magnetic recycling capability, and heat-enduring stability. Through adsorption of methylene blue, a typical dyeing material, the core-shell-structured particles show a good adsorption capability of approximately 33 mg/L. The particles are easily and completely collected by magnets, which is possible due to the magnetic property of core CoFe2O4. Heat treatment can burn out the adsorbed dyes and good adsorption performance is sustained even after several heat-treating loops. This property overcomes the common problem of particles with Fe3O4 as a core, by which Fe3O4 is oxidized to nonmagnetic α-Fe2O3 at the burning temperature. We also designed a miniature of effluent-treating pipeline, which demonstrates the potential of the application.

  7. The Results of the CCI-3 Reactor Material Experiment Investigating 2-D Core-Concrete Interaction and Debris Coolability with a Siliceous Concrete Crucible

    International Nuclear Information System (INIS)

    Farmer, M.T.; Lomperski, S.; Basu, S.

    2006-01-01

    The OECD-sponsored Melt Coolability and Concrete Interaction (MCCI) program conducted reactor materials experiments and associated analysis to achieve the following two objectives: 1) resolve the ex-vessel debris coolability issue, and 2) address remaining uncertainties related to long-term two-dimensional molten core-concrete interactions under both wet and dry cavity conditions. Achievement of these two objectives will demonstrate the efficacy of severe accident management guidelines for existing plants, and provide the technical basis for better containment designs of future plants. With respect to the second objective, there are remaining uncertainties in the models that evaluate the lateral vs. axial power split during core-concrete interaction because of a lack of truly two-dimensional experiment data. As a result, there are differences in the 2-D cavity erosion profiles predicted by codes such as WECHSL, COSACO, TOLBIAC, MEDICIS, and MELCOR. In the continuing effort to bridge this data gap, the third in a series of large scale Core-Concrete Interaction experiments (CCI-3) has been conducted as part of the MCCI program. This test investigated the long-term interaction of a 375 kg core-oxide melt within a two-dimensional siliceous concrete crucible. The initial phase of the test was conducted under dry conditions. After a predetermined time interval, the cavity was flooded with water to obtain data on the coolability of a core melt after core-concrete interaction has progressed for some time. This paper provides a description of the facility and an overview of results from this test. (authors)

  8. Nuclear fuel particles with a core of fissible or fertile material and method of production of such nuclear fuel particles

    International Nuclear Information System (INIS)

    Chin, J.; Luby, C.S.; Mills, R.G.

    1975-01-01

    The method deals with the coating of 4 layers on a fuel core: a first layer of pyrolytic carbon, the second layer of non-penetrable carbon, a third of dense silicon or zirconium carbide, as well as a fourth layer of dense pyrolytic carbon. The precipitation takes place in an atmosphere of hydrocarbons. (UA/LH) [de

  9. Influence of particle size and shell thickness of core-shell packing materials on optimum experimental conditions in preparative chromatography.

    Science.gov (United States)

    Horváth, Krisztián; Felinger, Attila

    2015-08-14

    The applicability of core-shell phases in preparative separations was studied by a modeling approach. The preparative separations were optimized for two compounds having bi-Langmuir isotherms. The differential mass balance equation of chromatography was solved by the Rouchon algorithm. The results show that as the size of the core increases, larger particles can be used in separations, resulting in higher applicable flow rates, shorter cycle times. Due to the decreasing volume of porous layer, the loadability of the column dropped significantly. As a result, the productivity and economy of the separation decreases. It is shown that if it is possible to optimize the size of stationary phase particles for the given separation task, the use of core-shell phases are not beneficial. The use of core-shell phases proved to be advantageous when the goal is to build preparative column for general purposes (e.g. for purification of different products) in small scale separations. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. In Vitro Assessment of Retention and Resistance Failure Loads of Teeth Restored with a Complete Coverage Restoration and Different Core Materials.

    Science.gov (United States)

    Tsiagali, Vasileia; Kirmanidou, Yvoni; Pissiotis, Argirios; Michalakis, Konstantinos

    2017-11-16

    To investigate in vitro the retention and the resistance form, as well as the failure modes of maxillary premolars restored with cast metal crowns and different core materials. Sixty human extracted maxillary premolars were selected according to their size and were embedded in PMMA resin blocks. After removing a part of their clinical crowns, the teeth were randomly divided into 3 groups of 20 teeth and were either left unrestored, or they were restored with amalgam or composite resin. All teeth were prepared for a cast metal complete coverage restoration. The restorations were cemented on the prepared teeth with a resin-modified glass ionomer luting agent (GC Fuji Plus). All specimens were subjected to static loading at 1 mm/min by a universal testing machine, until failure. Half the specimens of each group were subjected to tensile loading along the long axis of the teeth. The other half were subjected to compressive loading at a 30° angle. Failure loads and failure modes for each tooth were recorded. The statistical analysis included descriptive statistics, one-way ANOVA, and Tukey's HSD test. One-way ANOVA revealed statistically significant differences among the 3 tested groups (p material presented the highest failure loads for both the tensile and the compressive loading tests, with mean loads of 381.02 Ν and 741.21 Ν, respectively. Mean tensile and compressive failure loads for the amalgam group were 277.34 Ν and 584.75 Ν, while the composite resin group presented the lowest tensile and compressive failure values, which were 250.77 Ν and 465.78 Ν, respectively. The compression loading test resulted in the same failure mode for all specimens, which included unfavorable fracture of the teeth in combination with detachment of the cast metal complete coverage restorations. The tensile loading test resulted in different failure modes between the groups that used a core material and the group with no core material. Teeth that lost more than half of their

  11. A Core-Shell Fe/Fe2 O3 Nanowire as a High-Performance Anode Material for Lithium-Ion Batteries.

    Science.gov (United States)

    Na, Zhaolin; Huang, Gang; Liang, Fei; Yin, Dongming; Wang, Limin

    2016-08-16

    The preparation of novel one-dimensional core-shell Fe/Fe2 O3 nanowires as anodes for high-performance lithium-ion batteries (LIBs) is reported. The nanowires are prepared in a facile synthetic process in aqueous solution under ambient conditions with subsequent annealing treatment that could tune the capacity for lithium storage. When this hybrid is used as an anode material for LIBs, the outer Fe2 O3 shell can act as an electrochemically active material to store and release lithium ions, whereas the highly conductive and inactive Fe core functions as nothing more than an efficient electrical conducting pathway and a remarkable buffer to tolerate volume changes of the electrode materials during the insertion and extraction of lithium ions. The core-shell Fe/Fe2 O3 nanowire maintains an excellent reversible capacity of over 767 mA h g(-1) at 500 mA g(-1) after 200 cycles with a high average Coulombic efficiency of 98.6 %. Even at 2000 mA g(-1) , a stable capacity as high as 538 mA h g(-1) could be obtained. The unique composition and nanostructure of this electrode material contribute to this enhanced electrochemical performance. Due to the ease of large-scale fabrication and superior electrochemical performance, these hybrid nanowires are promising anode materials for the next generation of high-performance LIBs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. First in-core measurement results obtained with the innovative mobile calorimeter CALMOS inside the OSIRIS material testing reactor

    International Nuclear Information System (INIS)

    Carcreff, Hubert; Salmon, Laurent; Courtaux, Cedric

    2014-01-01

    Nuclear heating rate inside an MTR has to be known in order to design and to run irradiation experiments which have to fulfill target temperature constraints. This measurement is usually carried out by calorimetry. An innovative calorimetric system, CALMOS, has been studied and built in 2011 for the 70 MWth OSIRIS reactor operated by CEA. Thanks to a new calorimetric probe, associated to a specific displacement system, it provides measurements along the fissile height and above the core. Development of the calorimetric probe required manufacturing and irradiation of mock-ups in the ex-core area, where nuclear heating rate does not exceed 2 W.g -1 . The calorimeter working mode, the different measurement procedures, main modeling and ex-core experimental results have been already presented in previous papers. In this paper, we present in-core results obtained from 2011 to 2013 with the final device. For the first time, this new experimental measurement system was operated in several experimental locations, with nominal in-core thermal hydraulic conditions, nominal neutron flux and nuclear heating rate up to 6 W.g -1 (in graphite). After a brief presentation of the displacement system specificities, first nuclear heating distributions are presented and discussed. The Finite Element model of the calorimeter was upgraded in order to match calculated temperatures with measured ones. This 'validated' model allowed to estimate a Kc factor which tends to correct small nonlinearities when heating rate is calculated from the 'calibration method'. A comparison is made between nuclear heating rates determined from 'calibration' and 'zero methods'. In addition, an evaluation of the global uncertainty associated to the measurements is detailed. Finally, a comparison is made with available measurements obtained from previous calorimeters. (authors)

  13. Évaluation de la fracturation des réservoirs par forages : comparaison entre les données de carottes et d'imagerie de paroi Assessment of Reservoir Fracturing from Boreholes : Comparison Between Core and Wall-Image Data

    Directory of Open Access Journals (Sweden)

    Genter A.

    2006-11-01

    étecter que les fractures ayant au moins cette épaisseur de colmatage. Dans les formations de Balazuc, 6 % des fractures sont détectées par le FMS, ce qui correspond exactement à la proportion de fractures dont la taille est supérieure à la résolution de l'outil. Malgré ces biais d'échantillonnage, les directions majeures de fracturation sont correctement détectées avec les deux techniques mises en oeuvre. Deep drilling was carried out of two sedimentary sequences considered as representative of reservoir formations; one at Soultz-sous-Forêts in Alsace and the other at Balazuc in the Ardèche, France. The natural fracturing in these predominantly sandstone sequences has been analysed both from the continuous cores collected during the drilling and from wall imagery obtained by acoustic (BHTV and electric (FMS methods. This core-imagery comparison shows, quite logically, that the core analysis gives more complete results than the interpretation of wall imagery. With the BHTV it was possible to characterize 50% of the fractures seen in the cores, as against only 6% using the FMS. In the Bundsandstein at Soultz the fractures that form clusters (i. e. very close to one another are not correctly recorded by the BHTV. This bias is even more significant with the FMS since it applies to the entire fracture distribution, regardless of the fracture spacing. This fracture-detection filtering that we find with the imagery techniques are even more evident where the fractures are filled (little physical contrast or small (below the detection threshold. The core-imagery comparison also shows that the horizontal resolution of the imaging tool is directly proportional to the number of fractures detected. The BHTV, which has a resolution of between 1 and 2 mm, does not detect fractures of this thickness or less, i. e. 45% of the population. This percentage is similar to the amount of fractures recognized by BHTV compared to that recorded in core. The FMS, with a much coarser

  14. First In-Core Measurement Results Obtained with the Innovative Mobile Calorimeter CALMOS inside the OSIRIS Material Testing Reactor

    International Nuclear Information System (INIS)

    Carcreff, Hubert; Salmon, Laurent; Courtaux, Cedric

    2013-06-01

    Nuclear heating rate inside an MTR has to be known in order to design and to run irradiation experiments which have to fulfill target temperature constraints. This measurement is usually carried out by calorimetry [1, 2]. An innovative calorimetric system, CALMOS, has been studied and built in 2011 for the 70 MWth OSIRIS reactor operated by CEA. Thanks to a new calorimetric probe, associated to a specific displacement system, it provides measurements along the fissile height and above the core. The development of the calorimetric probe required the manufacturing and the irradiation of mock-ups in the ex-core area, where nuclear heating rate does not exceed 2 W.g -1 . The calorimeter working mode, the different measurement procedures allowed with such a new probe and main modeling and experimental results have been already presented [3, 4]. In this paper, we present the first results obtained during several measurement campaigns carried out in 2012 and 2013 inside the OSIRIS core with the final device. For the first time, this new experimental measurement system was operated in nominal in-core thermo hydraulic conditions with nominal neutron and gamma fluxes (up to 6 W.g -1 ) in several experimental locations. After a brief presentation of the displacement system specificities, first nuclear heating distributions are presented and discussed. Experimental data were also used to upgrade the Finite Element model of the calorimeter in order to match measured temperatures with calculated ones. This model allowed to estimate a Kc correction factor which takes into account small nonlinearities when the heating rate is deduced from the calibration method. A comparison is made between nuclear heating rates determined from the probe calibration and from the zero method. In addition, an evaluation of the global uncertainty associated to the measurements is detailed. Finally, a global comparison is made with available measurements obtained from previous calorimeters. (authors)

  15. Measuring of electrical changes induced by in situ combustion through flow-through electrodes in a laboratory sample of core material

    Science.gov (United States)

    Lee, David O.; Montoya, Paul C.; Wayland, Jr., James R.

    1986-01-01

    Method and apparatus are provided for obtaining accurate dynamic measurements for passage of phase fronts through a core sample in a test fixture. Flow-through grid structures are provided for electrodes to permit data to be obtained before, during and after passage of a front therethrough. Such electrodes are incorporated in a test apparatus for obtaining electrical characteristics of the core sample. With the inventive structure a method is provided for measurement of instabilities in a phase front progressing through the medium. Availability of accurate dynamic data representing parameters descriptive of material characteristics before, during and after passage of a front provides a more efficient method for enhanced recovery of oil using a fire flood technique.

  16. Characterization of oil and gas reservoir heterogeneity

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

    The objective of the cooperative research program is to characterize Alaskan reservoirs in terms of their reserves, physical and chemical properties, geologic configuration and structure, and the development potential. The tasks completed during this period include: (1) geologic reservoir description of Endicott Field; (2) petrographic characterization of core samples taken from selected stratigraphic horizons of the West Sak and Ugnu (Brookian) wells; (3) development of a polydispersed thermodynamic model for predicting asphaltene equilibria and asphaltene precipitation from crude oil-solvent mixtures, and (4) preliminary geologic description of the Milne Point Unit.

  17. Radioactivity material release mechanism and emergency radiation monitor requirements of personnel in core meltdown accident for submarine nuclear power plants

    International Nuclear Information System (INIS)

    Zhang Jianguo; Wang Yuexing; Ma Xingtian

    1999-01-01

    Some release mechanism of fission products from core meltdown accident of submarine nuclear power plants is described, which include gas-gap, melting, vaporization, steam and explosion. The further release process of them to cabins and environment is described too. The basic requirements and contents of emergency radiation monitor for personnel are approached. A tentative idea of forming emergency radiation monitor net of submarine nuclear power plants and the issue of neutron monitor and protect in the nuclear accident emergency rescue are put forward

  18. Fracture Resistance of Endodontically Treated Teeth Restored with 2 Different Fiber-reinforced Composite and 2 Conventional Composite Resin Core Buildup Materials: An In Vitro Study.

    Science.gov (United States)

    Eapen, Ashly Mary; Amirtharaj, L Vijay; Sanjeev, Kavitha; Mahalaxmi, Sekar

    2017-09-01

    The purpose of this in vitro study was to comparatively evaluate the fracture resistance of endodontically treated teeth restored with 2 fiber-reinforced composite resins and 2 conventional composite resin core buildup materials. Sixty noncarious unrestored human maxillary premolars were collected, endodontically treated (except group 1, negative control), and randomly divided into 5 groups (n = 10). Group 2 was the positive control. The remaining 40 prepared teeth were restored with various direct core buildup materials as follows: group 3 teeth were restored with dual-cure composite resin, group 4 with posterior composite resin, group 5 with fiber-reinforced composite resin, and group 6 with short fiber-reinforced composite resin. Fracture strength testing was performed using a universal testing machine. The results were statistically analyzed by 1-way analysis of variance and the post hoc Tukey test. Fracture patterns for each sample were also examined under a light microscope to determine the level of fractures. The mean fracture resistance values (in newtons) were obtained as group 1 > group 6 > group 4 > group 3 > group 5 > group 2. Group 6 showed the highest mean fracture resistance value, which was significantly higher than the other experimental groups, and all the fractures occurred at the level of enamel. Within the limitations of this study, a short fiber-reinforced composite can be used as a direct core buildup material that can effectively resist heavy occlusal forces against fracture and may reinforce the remaining tooth structure in endodontically treated teeth. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  19. Top-Down, Intelligent Reservoir Model

    Science.gov (United States)

    Mohaghegh, Shahab

    2010-05-01

    Conventional reservoir simulation and modeling is a bottom-up approach. It starts with building a geological model of the reservoir that is populated with the best available petrophysical and geophysical information at the time of development. Engineering fluid flow principles are added and solved numerically so as to arrive at a dynamic reservoir model. The dynamic reservoir model is calibrated using the production history of multiple wells and the history matched model is used to strategize field development in order to improve recovery. Top-Down, Intelligent Reservoir Modeling approaches the reservoir simulation and modeling from an opposite angle by attempting to build a realization of the reservoir starting with the measured well production behavior (history). The production history is augmented by core, log, well test and seismic data in order to increase the accuracy of the Top-Down modeling technique. Although not intended as a substitute for the conventional reservoir simulation of large, complex fields, this novel approach to reservoir modeling can be used as an alternative (at a fraction of the cost) to conventional reservoir simulation and modeling in cases where performing conventional modeling is cost (and man-power) prohibitive. In cases where a conventional model of a reservoir already exists, Top-Down modeling should be considered as a compliment to, rather than a competition for the conventional technique, to provide an independent look at the data coming from the reservoir/wells for optimum development strategy and recovery enhancement. Top-Down, Intelligent Reservoir Modeling starts with well-known reservoir engineering techniques such as Decline Curve Analysis, Type Curve Matching, History Matching using single well numerical reservoir simulation, Volumetric Reserve Estimation and calculation of Recovery Factors for all the wells (individually) in the field. Using statistical techniques multiple Production Indicators (3, 6, and 9 months cum

  20. Down-selection of candidate alloys for further testing of advanced replacement materials for LWR core internals

    Energy Technology Data Exchange (ETDEWEB)

    Was, Gary [Univ. of Michigan, Ann Arbor, MI (United States). Applied Physics Program; Leonard, Keith J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Tan, Lizhen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-09-01

    Life extension of the existing nuclear reactors imposes irradiation of high fluences to structural materials, resulting in significant challenges to the traditional reactor materials such as type 304 and 316 stainless steels. Advanced alloys with superior radiation resistance will increase safety margins, design flexibility, and economics for not only the life extension of the existing fleet but also new builds with advanced reactor designs. The Electric Power Research Institute (EPRI) teamed up with Department of Energy (DOE) Light Water Reactor Sustainability Program to initiate the Advanced Radiation Resistant Materials (ARRM) program, aiming to identify and develop advanced alloys with superior degradation resistance in light water reactor (LWR)-relevant environments by 2024.

  1. The role of magma ocean material in determining the formation and evolution of liquid-metal diapirs with trailing conduits during core formation

    Science.gov (United States)

    Rains, C.; Weeraratne, D. S.

    2013-12-01

    Formation of the early Earth involved violent impacts which partially or fully melted the planet's surface materials, facilitating separation of iron metal from silicates. Geochemical constraints on core formation times indicate that this metal must have been transported to the center of the Earth within 30 Ma. Among the mechanisms that have been proposed, metal-silicate plumes resulting from Rayleigh-Taylor instabilities of liquid-metal ponds at the bottom of magma oceans provide the fastest rates of delivery to the core. These plumes consist of liquid-metal diapirs with trailing conduits of entrained silicate material. However, while large plumes descend quickly, they do not provide enough time or surface area for metal-silicate equilibration to be achieved throughout the mantle. Instead, small metal drops that form a diapir made of a liquid emulsion or descending in the wake of larger diapirs may have been crucial in the equilibration process that resulted in the excess siderophile mantle abundance. The physical properties of a magma ocean such as its density, viscosity, or volume are unknown and may vary depending on the composition and properties of the impactor. Entrainment of this material behind a sinking metal plume may affect the time for core formation and lower mantle mixing. We investigate the descent of liquid-metal drops using liquid gallium and dehydrated or diluted glucose and salt solutions. We scale our experiments to the Earth's mantle through the use of low Reynolds numbers to characterize the Stokes flow regime and a non-dimensional length scale λ, defined as the ratio of conduit radius to conduit height that ranges from ~0.05 to ~0.2. We focus on low-Bond-number deformable metal drops with Bo mathematical expression for the shape of the conduit. Open conduits may entrain magma-ocean material to the base of the mantle, with return flow occurring either via solitons that travel upward along the original conduit path, or more shallowly due to

  2. Prediction of diagenesis and reservoir quality using wireline logs ...

    African Journals Online (AJOL)

    Reservoir quality is mainly controlled by environment deposit type and diagenesis processes. To investigate such subject we usually proceed to microscopic techniques. Absence of outcrops and missing of core samples let us use conventional wireline logs and core lab measurements as primary data. Direct lecture of well ...

  3. Simulation of the mulltizones clastic reservoir: A case study of Upper Qishn Clastic Member, Masila Basin-Yemen

    Science.gov (United States)

    Khamis, Mohamed; Marta, Ebrahim Bin; Al Natifi, Ali; Fattah, Khaled Abdel; Lashin, Aref

    2017-06-01

    The Upper Qishn Clastic Member is one of the main oil-bearing reservoirs that are located at Masila Basin-Yemen. It produces oil from many zones with different reservoir properties. The aim of this study is to simulate and model the Qishn sandstone reservoir to provide more understanding of its properties. The available, core plugs, petrophysical, PVT, pressure and production datasets, as well as the seismic structural and geologic information, are all integrated and used in the simulation process. Eclipse simulator was used as a powerful tool for reservoir modeling. A simplified approach based on a pseudo steady-state productivity index and a material balance relationship between the aquifer pressure and the cumulative influx, is applied. The petrophysical properties of the Qishn sandstone reservoir are mainly investigated based on the well logging and core plug analyses. Three reservoir zones of good hydrocarbon potentiality are indicated and named from above to below as S1A, S1C and S2. Among of these zones, the S1A zone attains the best petrophysical and reservoir quality properties. It has an average hydrocarbon saturation of more than 65%, high effective porosity up to 20% and good permeability record (66 mD). The reservoir structure is represented by faulted anticline at the middle of the study with a down going decrease in geometry from S1A zone to S2 zone. It is limited by NE-SW and E-W bounding faults, with a weak aquifer connection from the east. The analysis of pressure and PVT data has revealed that the reservoir fluid type is dead oil with very low gas liquid ratio (GLR). The simulation results indicate heterogeneous reservoir associated with weak aquifer, supported by high initial water saturation and high water cut. Initial oil in place is estimated to be around 628 MM BBL, however, the oil recovery during the period of production is very low (<10%) because of the high water cut due to the fractures associated with many faults. Hence, secondary and

  4. Transport of reservoir fines

    DEFF Research Database (Denmark)

    Yuan, Hao; Shapiro, Alexander; Stenby, Erling Halfdan

    Modeling transport of reservoir fines is of great importance for evaluating the damage of production wells and infectivity decline. The conventional methodology accounts for neither the formation heterogeneity around the wells nor the reservoir fines’ heterogeneity. We have developed an integral...

  5. SILTATION IN RESERVOIRS

    African Journals Online (AJOL)

    Calls have been made to the government through various media to assist its populace in combating this nagging problem. It was concluded that sediment maximum accumulation is experienced in reservoir during the periods of maximum flow. Keywords: reservoir model, siltation, sediment, catchment, sediment transport. 1.

  6. Dynamic reservoir well interaction

    NARCIS (Netherlands)

    Sturm, W.L.; Belfroid, S.P.C.; Wolfswinkel, O. van; Peters, M.C.A.M.; Verhelst, F.J.P.C.M.

    2004-01-01

    In order to develop smart well control systems for unstable oil wells, realistic modeling of the dynamics of the well is essential. Most dynamic well models use a semi-steady state inflow model to describe the inflow of oil and gas from the reservoir. On the other hand, reservoir models use steady

  7. Reservoir Engineering Management Program

    Energy Technology Data Exchange (ETDEWEB)

    Howard, J.H.; Schwarz, W.J.

    1977-12-14

    The Reservoir Engineering Management Program being conducted at Lawrence Berkeley Laboratory includes two major tasks: 1) the continuation of support to geothermal reservoir engineering related work, started under the NSF-RANN program and transferred to ERDA at the time of its formation; 2) the development and subsequent implementation of a broad plan for support of research in topics related to the exploitation of geothermal reservoirs. This plan is now known as the GREMP plan. Both the NSF-RANN legacies and GREMP are in direct support of the DOE/DGE mission in general and the goals of the Resource and Technology/Resource Exploitation and Assessment Branch in particular. These goals are to determine the magnitude and distribution of geothermal resources and reduce risk in their exploitation through improved understanding of generically different reservoir types. These goals are to be accomplished by: 1) the creation of a large data base about geothermal reservoirs, 2) improved tools and methods for gathering data on geothermal reservoirs, and 3) modeling of reservoirs and utilization options. The NSF legacies are more research and training oriented, and the GREMP is geared primarily to the practical development of the geothermal reservoirs. 2 tabs., 3 figs.

  8. [Preparation and release mechanism of gestodene reservoir-type intravaginal rings].

    Science.gov (United States)

    Li, Chun-Xiao; Wang, Yan-Kun; Ning, Mei-Ying

    2014-03-01

    This study taking gestodene (GEST) as a model, investigated the factors affecting reservoir-type intravaginal ring (IVR)'s drug release. This paper reported a gestodene intravaginal ring of reservoir design, comprising a gestodene silicone elastomer core encased in a non-medicated silicone sheath, separately manufactured by reaction injection moulding at 80 degrees C and heating vulcanization at 130 degrees C is reported. The test investigated the factors affecting drug release through a single variable method, taking the drug release rates of 21 days as standards. When changing the thickness of the controlling sheath outside, the ratio of the first day of drug release and mean daily release (MDR), named the relatively burst effect, is closing to 1 with the thickness of controlling sheath increasing, while the 1.25 mm sheath corresponding to 1.04 controlled the burst release effectively; a positive correlation (r = 0.992 2) existed between the average drug release (Q/t) and drug loading (A) within a certain range. The C6-165 controlling sheath with high solubility of GEST is easier to achieve controlled release of the drug; GEST crystalline power is more effective to implement controlled release of drugs among difficent states of the drug. A 1/4 fractional segment core gives a relatively burst effect of 1.76, while the 1/1 and 1/2 are 1.93 and 1.87 separately, at the same drug loading, concluding that use of a fractional segment core would allow development of a suitable GEST reservoir IVR. In summary, GEST reservoir-type IVR could be adjusted by the thickness of controlling sheath, the loading of drug, the material properties of controlling sheath, the dispersion state of drug, the additive composition and structure of intravaginal ring, to control the drug release behavior and achieve the desired drug release rate.

  9. Analysis of a Neutronic Computational Model for the Core of Material Testing Reactor MTR by Using SQUID Code

    International Nuclear Information System (INIS)

    Al-Taweel, M.H.

    2015-01-01

    It is a conventional practice in the design of nuclear reactor to introduce calculation of hot points to determine spatial variation for energy generated and then determine power distribution.The study had been carried out for core of a reactor type (MTR) by the neutronic code SQUID. In this study, we replace the reflector of the reactor by H 2 O instead of D 2 O as originally the reactor designed.From the study we conclude that the reactor can operates safely, to make sure of that we calculate the multiplication factor where their values ranged from (1.0854) when all control rods are up to (1.001)when three control rods are up.Also the values of hot points were calculated and compared with French documents results with D 2 O as a reflector where the difference is (0.19%), and with light water as reflector instead of heavy water was calculated.For different cases according to control rod position , the values of hot point ranged between (0.46) to (1.64) in case all control rods are up also the values of the average power distributed on different fuel cells were calculated in case of light water as reflector firstly with three control rods are down and the maximum value (2.13*10 -2 Μw).Secondly in case offour control rods are down, the maximum value (1.925*10 -2 Μw) we notice almost coincidence between the neutron flux distribution through the core of reactor and in different positions of control rods

  10. Fracture resistance of endodontically treated teeth restored with short fiber composite used as a core material-An in vitro study.

    Science.gov (United States)

    Garlapati, Tejesh Gupta; Krithikadatta, Jogikalmat; Natanasabapathy, Velmurugan

    2017-10-01

    This in-vitro study tested the fracture resistance of endodontically treated molars with Mesial-Occluso-Distal (MOD) cavities restored with fibre reinforced composite material everX posterior in comparision with hybrid composite and ribbond fiber composite. Fifty intact freshly extracted human mandibular first molars were collected and were randomly divided into five groups (n=10). Group 1: positive control (PC) intact teeth without any endodontic preparation. In groups 2 through 6 after endodontic procedure standard MOD cavities were prepared and restored with their respective core materials as follows: group 2, negative control (NC) left unrestored or temporary flling was applied. Group 3, Hybrid composite (HC) as a core material (Te-Econom Plus Ivoclar Vivadent Asia) group 4, Ribbond (Ribbond; Seattle, WA, USA)+conventional composite resin (RCR) group 5, everX posterior (everX Posterior GC EUROPE)+conventional composite resin (EXP) after thermocycling fracture resistance for the samples were tested using universal testing machine. The results were analysed using ANOVA and Tukey's HSD post hoc tests. Mean fracture resistance (in Newton, N) was group 1: 1568.4±221.71N, group 2: 891.0±50.107N, group 3: 1418.3±168.71N, group 4:1716.7±199.51N and group 5: 1994.8±254.195N. Among the materials tested, endodontically treated teeth restored with everX posterior fiber reinforced composite showed superior fracture resistance. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  11. Polyaniline/multi-walled carbon nanotubes composite with core-shell structures as a cathode material for rechargeable lithium-polymer cells

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Pan [School of Marine Science and Technology, Harbin Institute of Technology, Weihai 264209 (China); Han, Jia-Jun, E-mail: hanjiajunhitweihai@163.com [School of Marine Science and Technology, Harbin Institute of Technology, Weihai 264209 (China); Jiang, Li-Feng [Dalian Chemical Institute of Chinese Academy of Sciences, Dalian 116011 (China); Li, Zhao-Yu; Cheng, Jin-Ning [School of Marine Science and Technology, Harbin Institute of Technology, Weihai 264209 (China)

    2017-04-01

    Highlights: • The polyaniline multi-walled carbon nanotubes composite with core-shell structures was synthetized via in situ chemical oxidative polymerization, and the materials were characterized by physical and chemical methods. • The PANI/WMCNTs was synthetized via in situ chemical oxidative polymerization with core-shell structures. • The WMCNTs highly enhanced the conductivity of composites. • The comopsites were more conducive to the intercalation and deintercalation of anions and cations. • The much better performance as the cathode for lithium-ion cells was acquired for the composites. • The composites are low cost and eco-friendly which have a good prospect in future. - Abstract: The aniline was polymerized onto functionalized multi-walled carbon nanotubes in order to obtain a cathode material with core-shell structures for lithium batteries. The structure and morphology of the samples were investigated by Fourier transform infrared spectroscopy analysis, scanning electron microscope, transmission electron microscope and X-ray diffraction. The electrochemical properties of the composite were characterized by the cyclic voltammetry, the charge/discharge property, coulombic efficiency, and ac impedance spectroscopy in detail. At a constant current density of 0.2 C, the first specific discharge capacity of the reduced and oxidized PANI/WMCNTs were 181.8 mAh/g and 135.1 mAh/g separately, and the capacity retention rates were corresponding to 76.75% and 86.04% for 100 cycles with 99% coulombic efficiency. It was confirmed that the CNTs obviously enhanced the conductivity and electrochemical performance of polyaniline, and compared with the pure PANI, the reduced composite possessed a quite good performance for the cathode of lithium batteries.

  12. Fabrication of Core-Shell Structural SiO2@H3[PM12O40] Material and Its Catalytic Activity

    Directory of Open Access Journals (Sweden)

    Xin Yang

    2014-01-01

    Full Text Available Through a natural tree grain template and sol-gel technology, the heterogeneous catalytic materials based on polyoxometalate compounds H3[PM12O40] encapsulating SiO2: SiO2@H3[PM12O40] (SiO2@PM12, M = W, Mo with core-shell structure had been prepared. The structure and morphology of the core-shell microspheres were characterized by the XRD, IR spectroscopy, UV-Vis absorbance, and SEM. These microsphere materials can be used as heterogeneous catalysts with high activity and stability for catalytic wet air oxidation of pollutant dyes safranine T (ST at room condition. The results show that the catalysts have excellent catalytic activity in treatment of wastewater containing 10 mg/L ST, and 94% of color can be removed within 60 min. Under different cycling runs, it is shown that the catalysts are stable under such operating conditions and the leaching tests show negligible leaching effect owing to the lesser dissolution.

  13. Impact of fault damage zones on reservoir performance in the Hibernia oilfield (Jeanne d'Arc Basin, Newfoundland) : an analysis of structural, petrophysical and dynamic well-test data

    Energy Technology Data Exchange (ETDEWEB)

    Porter, J.R.; McAllister, E.; Fisher, Q.J.; Knipe, R.J.; Condliffe, D.M.; Kay, M.A. [Leeds Univ., Leeds (United Kingdom). Dept. of Earth Sciences, Rock Deformation Research Group; Stylianides, G.; Sinclair, I.K. [Hibernia Management and Development Co. Ltd., St. John' s, NL (Canada)

    2005-07-01

    Petroleum reservoirs are typically characterized by combining conventional core analysis results, wire-line log data and sedimentological description with production data. This study emphasized the benefits of including structural analysis of core material as part of general reservoir characterization. In particular, it examined the influence of fault zones on fluid flow within the Hibernia Formation in the Hibernia Oilfield in the Jeanne d'Arc Basin on the Grand Banks of Newfoundland. The geologic setting and background to the Hibernia Field was presented. Fault seal analysis was used in the study to help manage the compartmentalized Hibernia Field. Cross-fault juxtaposition analysis was also integrated with structural logging and petrophysical measurement of core material. The analysis of core material resulted in an increased confidence in production data interpretation. The study also examined how deformation features present within the Hibernia Formation drill cores have the potential to act as baffles or seals to hydrocarbon flow. Deformation features were described with reference to low, intermediate and high clay content fault rocks. It was shown that fault rocks are capable of severely restricting fluid flow, particularly when close to production or injection wells. The targeting of wheels to avoid the damage-zone envelope associated with seismic-scale faults will result in a large improvement in producer-injector performance despite reducing the potential drainage volume. The results confirm that inclusion of structural analysis in reservoir characterization studies can have a great and positive impact on field management strategies. 31 refs., 2 tabs., 8 figs.

  14. Development of RBWR (Resource-renewable BWR) for recycling and transmutation of transuranium elements (3). Materials for core component

    International Nuclear Information System (INIS)

    Ishizaki, Takahiro; Maruno, Yusaku

    2017-01-01

    The next generation light water reactor called Resource Renewable BWR (RBWR) is currently under development in order to relieve radioactive waste problems such as spent nuclear fuel in Hitachi group. RBWR will be able to help shorten the isolation period of spent nuclear fuels from 100,000 years down to approximately 300 years by consuming Trans Uranium Element (TRU) as its nuclear fuel. However, for acquiring efficient combustion of TRU, the fast neutron rate in RBWR is required to be raised about 4 times higher than that in conventional ABWR, which means that the control rods of RBWR shall be irradiated by fast neutron irradiation at a dose of about 6.0×10 25 n/m 2 , much higher than 1.5×10 25 n/m 2 of ABWR. On the other hand, it is known if control rod material is irradiated with over 4.0×10 25 n/m 2 of fast neutron dose, irradiation-assisted stress corrosion cracking (IASCC) will occur, which means that the control rod of RBWR can possibly tolerate the operation of only one cycle before the critical irradiation degradation damage happens. Therefore structural material with both high corrosion resistance and high irradiation resistance is required for the development of RBWR systems. In this study, oxide dispersion strengthened austenitic stainless steels (ODS-ASUS) with high corrosion resistance have been developed for control rods designed for high-dosed neutron irradiation environment in RBWR. ODS-ASUS was produced experimentally by powder metallurgical process. It is well known that amount of oxygen in alloy has great effort on mechanical properties and corrosion resistance. The objective in this report is to evaluate effect of amount of oxygen in ODS-ASUS and selecting appropriate oxygen concentration for control rods. The materials for discussion in this study were ODS-ASUS-HO, ODS-ASUS-LO with oxygen concentration of 0.27 wt% and 0.018 wt% respectively. The current material of type 316L SS was used as a reference material. The grain size was measured

  15. Electrospun core-shell nanofibers derived Fe-S/N doped carbon material for oxygen reduction reaction

    Science.gov (United States)

    Guo, Junxia; Niu, Qijian; Yuan, Yichun; Maitlo, Inamullh; Nie, Jun; Ma, Guiping

    2017-09-01

    One-dimensional (1D) nanomaterials have gained attention in energy conversion, storage, and catalyst due to the unique physical and chemical properties. Electrospinning is a kind of simple, versatile, and cost-effective technology to fabricate 1D functional nanofibers. Herein, electrospun polyacrylonitrile (PAN), melamine, and ferric chloride hexahydrate (FeCl3·6H2O) composite nanofibers are used as template, and polythiophene (PT) are prepared by photopolymerization technology on the surface of electrospun nanofibers as shell part of fibers. Then, the core-shell nanofibers are pyrolyzed and converted into Fe-S/N-C nanofibers, which can be used as catalysts for ORR due to the metal and S-/N-codoped structure and unique 1D structure which provided facile pathways for efficient mass transport and charge transfer. The ORR electrocatalytic ability of Fe-S/N-C nanofibers is tested and present excellent property, especially in stability and methanol crossover. The electrocatalytic ability of sample is comparable to that of 20 wt% Pt/C benchmarks. These results offer an easy pathway for exploring metal-heteroatom-codoped carbon nanofibers applicable for ORR catalyst.

  16. Core-shell Ni0.5TiOPO4/C composites as anode materials in Li ion batteries

    International Nuclear Information System (INIS)

    Zhang, X.J.; Zhang, Y.; Zhou, Z.; Wei, J.P.; Essehli, R.; Bali, B. El

    2011-01-01

    Pristine Ni 0.5 TiOPO 4 was prepared via a traditional solid-state reaction, and then Ni 0.5 TiOPO 4 /C composites with core-shell nanostructures were synthesized by hydrothermally treating Ni 0.5 TiOPO 4 in glucose solution. X-ray diffraction patterns indicate that Ni 0.5 TiOPO 4 /C crystallizes in monoclinic P2 1 /c space group. Scanning electron microscopy and transmission electron microscopy show that the small particles with different sizes are coated with uniform carbon film of ∼3 nm in thickness. Raman spectroscopy also confirms the presence of carbon in the composites. Ni 0.5 TiOPO 4 /C composites presented a capacity of 276 mAh g -1 after 30 cycles at the current density of 42.7 mA g -1 , much higher than that of pristine Ni 0.5 TiOPO 4 (155 mAh g -1 ). The improved electrochemical performances can be attributed to the existence of carbon shell.

  17. Vinylation of a Secondary Amine Core with Calcium Carbide for Efficient Post-Modification and Access to Polymeric Materials

    Directory of Open Access Journals (Sweden)

    Konstantin S. Rodygin

    2018-03-01

    Full Text Available We developed a simple and efficient strategy to access N-vinyl secondary amines of various naturally occurring materials using readily available solid acetylene reagents (calcium carbide, KF, and KOH. Pyrrole, pyrazole, indoles, carbazoles, and diarylamines were successfully vinylated in good yields. Cross-linked and linear polymers were synthesized from N-vinyl carbazoles through free radical and cationic polymerization. Post-modification of olanzapine (an antipsychotic drug substance was successfully performed.

  18. Metal-Organic Framework Derived Iron Sulfide-Carbon Core-Shell Nanorods as a Conversion-Type Battery Material

    DEFF Research Database (Denmark)

    Huang, Wei; Li, Shuo; Cao, Xianyi

    2017-01-01

    of a redox conversion-type lithium-ion battery, this composite material has demonstrated high lithium-ion storage capacity at 1148 mA h g-1 under the current rate of 500 mA g-1 for 170 cycles and an impressive rate-retention capability at 657 mA h g-1 with a current density of 2000 mA g-1. On the basis...

  19. Sediment management for reservoir

    International Nuclear Information System (INIS)

    Rahman, A.

    2005-01-01

    All natural lakes and reservoirs whether on rivers, tributaries or off channel storages are doomed to be sited up. Pakistan has two major reservoirs of Tarbela and Managla and shallow lake created by Chashma Barrage. Tarbela and Mangla Lakes are losing their capacities ever since first impounding, Tarbela since 1974 and Mangla since 1967. Tarbela Reservoir receives average annual flow of about 62 MAF and sediment deposits of 0.11 MAF whereas Mangla gets about 23 MAF of average annual flows and is losing its storage at the rate of average 34,000 MAF annually. The loss of storage is a great concern and studies for Tarbela were carried out by TAMS and Wallingford to sustain its capacity whereas no study has been done for Mangla as yet except as part of study for Raised Mangla, which is only desk work. Delta of Tarbala reservoir has advanced to about 6.59 miles (Pivot Point) from power intakes. In case of liquefaction of delta by tremor as low as 0.12g peak ground acceleration the power tunnels I, 2 and 3 will be blocked. Minimum Pool of reservoir is being raised so as to check the advance of delta. Mangla delta will follow the trend of Tarbela. Tarbela has vast amount of data as reservoir is surveyed every year, whereas Mangla Reservoir survey was done at five-year interval, which has now been proposed .to be reduced to three-year interval. In addition suspended sediment sampling of inflow streams is being done by Surface Water Hydrology Project of WAPDA as also some bed load sampling. The problem of Chasma Reservoir has also been highlighted, as it is being indiscriminately being filled up and drawdown several times a year without regard to its reaction to this treatment. The Sediment Management of these reservoirs is essential and the paper discusses pros and cons of various alternatives. (author)

  20. Influence of different surface treatments on the short-term bond strength and durability between a zirconia post and a composite resin core material.

    Science.gov (United States)

    Akgungor, Gokhan; Sen, Deniz; Aydin, Murat

    2008-05-01

    Reliable bonding between zirconia posts and composite resin core materials is difficult to achieve because of the smooth surface texture and lack of silica content of zirconia posts. The purpose of this study was to evaluate the effect of different surface treatments on the short-term bond strength and durability between a zirconia post and a composite resin core material. Eighty zirconia posts were divided into 4 groups (n=20). Specimens received 1 of 4 different surface treatments: group AIRB, airborne-particle abrasion; group TSC-SIL, tribochemical silica coating (CoJet system) and silanization (ESPE Sil); group AIRB-BSIL, airborne-particle abrasion and MDP-containing primer (Clearfil SE Bond Primer)/silane coupling agent (Clearfil Porcelain Bond Activator) mixture application; and group TSC-BSIL, tribochemical silica coating and MDP-containing primer/silane coupling agent mixture application. Average surface roughness (Ra) of zirconia posts produced by airborne-particle abrasion or silica coating was measured using an optical profilometer. Composite resin core foundations (Build-it FR) were formed using transparent acrylic resin tubes (12mm in length and 7mm in diameter). Each group was further divided into 2 subgroups of 10 specimens and stored in distilled water at 37 degrees C, either for 24 hours or for 150 days with 37,500 thermal cycles between 5 degrees C and 55 degrees C, with a dwell time of 30 seconds. Following water storage, the specimens were sectioned perpendicular to the bonded interface into 2-mm-thick post-and-core specimens under water cooling. Push-out tests were performed with a universal testing machine at a crosshead speed of 0.5mm/min. Debonded post surfaces were examined with SEM. Data were analyzed with 1- and 2-way ANOVA and Tukey multiple comparison tests (alpha=0.05). No significant differences were detected between the Ra values of airborne-particle-abraded and silica-coated specimens (P=.781). The short-term mean bond strengths for

  1. Combined geophysical, geochemical and geological investigations of geothermal reservoir characteristics in Lower Saxony, Germany

    Science.gov (United States)

    Hahne, B.; Thomas, R.

    2012-04-01

    The North German basin provides a significant geothermal potential, although temperature gradients are moderate. However, deep drilling up to several thousand meters is required to reach temperatures high enough for efficient generation of geothermal heat and electric power. In these depths we have not much information yet about relevant physical properties like porosity or permeability of the rock formations. Therefore the costs of developing a geothermal reservoir and the risk of missing the optimum drilling location are high. The collaborative research association "Geothermal Energy and High Performance Drilling" (gebo) unites several universities and research institutes in Lower Saxony, Germany. It aims at a significant increase of economic efficiency by introducing innovative technology and high tech materials resisting temperatures up to 200 °C in the drilling process. Furthermore, a better understanding of the geothermal reservoir is essential. gebo is structured into four main fields: Drilling Technology, Materials, Technical Systems and Geosystem. Here, we show the combined work of the Geosystem group, which focuses on the exploration of geological fault zones as a potential geothermal reservoir as well as on modeling the stress field, heat transport, coupled thermo-hydro-mechanical processes, geochemical interactions and prediction of the long-term behavior of the reservoir. First results include combined seismic and geoelectric images of the Leinetalgraben fault system, a comparison of seismic images from P- and S-wave measurements, mechanical properties of North German rocks from field and laboratory measurements as well as from drill cores, seismological characterization of stimulated reservoirs, a thermodynamic "gebo" database for modeling hydrogeochemical processes in North German formation waters with high salinity and at high temperatures, stress models for specific sites in northern Germany, and modeling results of permeability and heat transport

  2. Fingerprinting the main erosion processes delivering sediment to hillside reservoirs: Case of Kamech catchment in Cape Bon, Tunisia

    Science.gov (United States)

    Ben Slimane, A.; Raclot, D.; Evrard, O.; Sanaa, M.; Lefèvre, I.; Ahmadi, M.; Le Bissonnais, Y.

    2011-12-01

    About 74% of agricultural soils are affected by water erosion in Tunisia. This intense soil degradation threatens the sustainability of food production in the country. It also leads to the siltation of the numerous hillslide reservoirs that were constructed in the 1990s to protect downstream villages against floods and provide a source of water in cultivated areas. Very dense gully systems are observed in Tunisian agricultural land and in other Mediterranean regions, but their contribution to contemporary sediment supply to hillside reservoirs has not been quantified yet. Still, there is a need to quantify the sediment sources in this region in order to guide the implementation of erosion control measures. Sediment can be supplied by gully systems but it can also be provided by erosion of the superficial layer of cultivated soil. We propose a methodology to estimate the relative contribution of gully erosion vs. interrill erosion to the sediment accumulated in hillside reservoirs. This work was conducted in a pilot catchment (i.e., Kamech catchment, 263ha, Cape Bon, Tunisia) to define guidelines on the number and the location of sediment core samples to collect in the reservoirs, in order to provide relevant information on the evolution of sediment sources throughout the last two decades. Once validated, this methodology will be applied to other catchments of the Tunisian Ridge. We applied the sediment fingerprinting method, which consists in measuring conservative and stable properties in both sources and sinks of sediment to outline their origin. Sampling efforts were concentrated on the field surface (cropland and grassland), gullies and channel banks. Thirteen sediment cores were collected along an upstream-downstream transect across Kamech hillside reservoir, in order to estimate the contribution of each potential sediment source to the material accumulated at the outlet, and to investigate the potential spatial differences of sediment origin across the

  3. The effect of winding and core support material on the thermal gain dependence of a fluxgate magnetometer sensor

    Science.gov (United States)

    Miles, David M.; Mann, Ian R.; Kale, Andy; Milling, David K.; Narod, Barry B.; Bennest, John R.; Barona, David; Unsworth, Martyn J.

    2017-10-01

    Fluxgate magnetometers are an important tool in geophysics and space physics but are typically sensitive to variations in sensor temperature. Changes in instrumental gain with temperature, thermal gain dependence, are thought to be predominantly due to changes in the geometry of the wire coils that sense the magnetic field and/or provide magnetic feedback. Scientific fluxgate magnetometers typically employ some form of temperature compensation and support and constrain wire sense coils with bobbins constructed from materials such as MACOR machinable ceramic (Corning Inc.) which are selected for their ultra-low thermal deformation rather than for robustness, cost, or ease of manufacturing. We present laboratory results comparing the performance of six geometrically and electrically matched fluxgate sensors in which the material used to support the windings and for the base of the sensor is varied. We use a novel, low-cost thermal calibration procedure based on a controlled sinusoidal magnetic source and quantitative spectral analysis to measure the thermal gain dependence of fluxgate magnetometer sensors at the ppm°C-1 level in a typical magnetically noisy university laboratory environment. We compare the thermal gain dependence of sensors built from MACOR, polyetheretherketone (PEEK) engineering plastic (virgin, 30 % glass filled and 30 % carbon filled), and acetal to examine the trade between the thermal properties of the material, the impact on the thermal gain dependence of the fluxgate, and the cost and ease of manufacture. We find that thermal gain dependence of the sensor varies as one half of the material properties of the bobbin supporting the wire sense coils rather than being directly related as has been historically thought. An experimental sensor constructed from 30 % glass-filled PEEK (21.6 ppm°C-1) had a thermal gain dependence within 5 ppm°C-1 of a traditional sensor constructed from MACOR ceramic (8.1 ppm°C-1). If a modest increase in thermal

  4. The effect of winding and core support material on the thermal gain dependence of a fluxgate magnetometer sensor

    Directory of Open Access Journals (Sweden)

    D. M. Miles

    2017-10-01

    Full Text Available Fluxgate magnetometers are an important tool in geophysics and space physics but are typically sensitive to variations in sensor temperature. Changes in instrumental gain with temperature, thermal gain dependence, are thought to be predominantly due to changes in the geometry of the wire coils that sense the magnetic field and/or provide magnetic feedback. Scientific fluxgate magnetometers typically employ some form of temperature compensation and support and constrain wire sense coils with bobbins constructed from materials such as MACOR machinable ceramic (Corning Inc. which are selected for their ultra-low thermal deformation rather than for robustness, cost, or ease of manufacturing. We present laboratory results comparing the performance of six geometrically and electrically matched fluxgate sensors in which the material used to support the windings and for the base of the sensor is varied. We use a novel, low-cost thermal calibration procedure based on a controlled sinusoidal magnetic source and quantitative spectral analysis to measure the thermal gain dependence of fluxgate magnetometer sensors at the ppm°C−1 level in a typical magnetically noisy university laboratory environment. We compare the thermal gain dependence of sensors built from MACOR, polyetheretherketone (PEEK engineering plastic (virgin, 30 % glass filled and 30 % carbon filled, and acetal to examine the trade between the thermal properties of the material, the impact on the thermal gain dependence of the fluxgate, and the cost and ease of manufacture. We find that thermal gain dependence of the sensor varies as one half of the material properties of the bobbin supporting the wire sense coils rather than being directly related as has been historically thought. An experimental sensor constructed from 30 % glass-filled PEEK (21.6 ppm°C−1 had a thermal gain dependence within 5 ppm°C−1 of a traditional sensor constructed from MACOR ceramic (8.1

  5. Proteomics Core

    Data.gov (United States)

    Federal Laboratory Consortium — Proteomics Core is the central resource for mass spectrometry based proteomics within the NHLBI. The Core staff help collaborators design proteomics experiments in a...

  6. Reservoir characterization of Pennsylvanian sandstone reservoirs. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kelkar, M.

    1995-02-01

    This final report summarizes the progress during the three years of a project on Reservoir Characterization of Pennsylvanian Sandstone Reservoirs. The report is divided into three sections: (i) reservoir description; (ii) scale-up procedures; (iii) outcrop investigation. The first section describes the methods by which a reservoir can be described in three dimensions. The next step in reservoir description is to scale up reservoir properties for flow simulation. The second section addresses the issue of scale-up of reservoir properties once the spatial descriptions of properties are created. The last section describes the investigation of an outcrop.

  7. Recent advances in the application of core-shell structured magnetic materials for the separation and enrichment of proteins and peptides.

    Science.gov (United States)

    Zhao, Man; Xie, Yiqin; Deng, Chunhui; Zhang, Xiangmin

    2014-08-29

    Many endogenous proteins/peptides and proteins/peptides with post-translational modifications (PTMs) are presented at extremely low abundance, and they usually suffer strong interference with highly abundant proteins/peptides as well as other contaminants, resulting in low ionization efficiency in MS analysis. Therefore, the separation and enrichment of proteins/peptides from complex mixtures is of great importance to the successful identification of them. Core-shell structured magnetic microspheres have been widely used in the enrichment and isolation of proteins/peptides, thanks to unique properties such as strong magnetic responsiveness, outstanding binding capacity, excellent biocompatibility, robust mechanical strength and admirable recoverability. The aim of this review is to update the advances in the application of core-shell structured magnetic materials for proteomics analysis, including the separation and enrichment of low-concentration proteins/peptides, the selective enrichment of phosphoproteins and the selective enrichment of glycoproteins, and to compare the enrichment performance of magnetic microspheres with different kinds of functionalization. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Facile synthesis of core-shell nanostructured hollow carbon nanospheres@nickel cobalt double hydroxides as high-performance electrode materials for supercapacitors.

    Science.gov (United States)

    Xu, Juan; Ma, Chaojie; Cao, Jianyu; Chen, Zhidong

    2017-03-07

    Core-shell nanostructured hollow carbon nanospheres@nickel cobalt double hydroxides (HCNs@NiCo-LDH) were fabricated using a facile hydrothermal method and investigated as high-performance electrode materials for supercapacitors. HCNs were acquired by a successive polymerization, carbonization and etching process, which was subsequently wrapped by ultrathin NiCo-LDH nanosheets. The HCNs@NiCo-LDH electrode achieved a high specific capacitance (2558 F g -1 at 1 A g -1 ) and outstanding rate capability with 74.9% capacitance retention after a 20-fold increase in current density. Capacitances of 2405, 2310, 2168, 2006 and 1916 F g -1 can be achieved at rates of 3, 5, 10, 15 and 20 A g -1 , respectively, which are much higher than the specific capacitances of most reported carbon loaded NiCo-LDH. Specifically, the assembled HCNs@NiCo-LDH//graphene asymmetric supercapacitor displayed distinguished capacitive behaviors with a prominent specific capacitance of 172.8 F g -1 and eminent cycling stability with 93.5% capacitance retention after 3000 cycles. These remarkable electrochemical properties indicate that the unique HCNs@NiCo-LDH core-shell electrode is highly promising for application in energy storage fields.

  9. ZnO@C (core@shell) microspheres derived from spent coffee grounds as applicable non-precious electrode material for DMFCs.

    Science.gov (United States)

    Ghouri, Zafar Khan; Al-Meer, Saeed; Barakat, Nasser A M; Kim, Hak Yong

    2017-05-11

    Although numerous reports have introduced non precious electrocatalysts for methanol oxidation, most of those studies did not consider the corresponding high onset potential which restricts utilization in real fuel cells. In this study, an -90 mV [vs. Ag/AgCl] onset potential non-precious electrocatalyst is introduced as an applicable anode material for the direct methanol fuel cells. Moreover, the proposed material was prepared from a cheap and abundantly existing resource; the spent coffee grounds. Typically, the spent coffee grounds were facilely converted to core@shell (ZnO@C) microspheres through a two-step approach, involving chemical activation and a subsequent calcination at temperature of 700 °C. Activation of the carbon derived from the spent coffee grounds was performed with ZnCl 2 which acts as pore-forming agent as well as a precursor for the ZnO. The structure and morphology were characterized by (XRD), (SEM), and (TEM) analyses while the electrochemical characterizations was evaluated by cyclic voltammetry (CV) technique. Besides the comparatively very low onset potential, the introduced microspheres exhibited relatively high current density; 17 mA/cm 2 . Overall, based on the advantages of the green source of carbon and the good electrocatalytic activity, the spent coffee grounds-derived carbon can be considered a promise anode material for the DMFCs.

  10. Materials

    CSIR Research Space (South Africa)

    Van Wyk, Llewellyn V

    2009-02-01

    Full Text Available community. The construction industry is a significantly consumer of materials, using 50 per cent of all products produced globally. Building materials is any material which is used for a construction purpose. Many of these materials are sources from natural...

  11. A study on synthesis and characterization of the core-shell materials of Mn{sub 1-x}Zn{sub x}Fe{sub 2}O{sub 4}-polyaniline

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.-P.; Chen, Y.-J.; Ho, C.-M.; Chang, C.-P. [Department of Applied Chemistry and Materials Science, Chung Cheng Institute of Technology, National Defense University, No. 190, Sanyuan 1st Street, Dasi Township, Taoyuan County 335, Taiwan (China); Hong, Y.-S. [Department of Applied Chemistry and Materials Science, Chung Cheng Institute of Technology, National Defense University, No. 190, Sanyuan 1st Street, Dasi Township, Taoyuan County 335, Taiwan (China)], E-mail: yshong@ccit.edu.tw

    2007-10-25

    Microwave absorbents with core-shell structure of Mn{sub 1-x}Zn{sub x}Fe{sub 2}O{sub 4}-polyaniline have been synthesized by the polymerization of aniline in the aqueous solution of aniline in the presence of surfactant NaDS and the nano-particle size powder of Mn{sub 1-x}Zn{sub x}Fe{sub 2}O{sub 4}. The nano-particle size of Mn{sub 1-x}Zn{sub x}Fe{sub 2}O{sub 4} was prepared with the method of self-propagation combustion of the aqueous sol-gel. X-ray powder diffraction of ferrites indicated that the structure of core materials is spinel structures with lattice constants around 8.44-8.40 A. SEM and TEM photographs show that the particle size of core material are around 100-200 nm. After coating with polyaniline, the particle size of the core-shell of ferrite-polyaniline has grown up to 400-800 nm. The conductivity of the core materials ferrites and of the core-shell materials of the ferrite-polyaniline measured by the four-point probe resistivity are 10{sup -5} {omega}{sup -1} cm{sup -1} and 10{sup -1} {omega}{sup -1} cm{sup -1}, respectively. The conductivity of the core-shell materials increase with the increasing of the amount of polyaniline in the resulting products. The magnetic hysteresis loops of materials investigated with VSM indicate that the saturated magnetization (M{sub s}) of pure spinel ferrites of Mn{sub 1-x}Zn{sub x}Fe{sub 2}O{sub 4} increase with the x value up to 47.01 emu/g for Mn{sub 0.50}Zn{sub 0.50}Fe{sub 2}O{sub 4}, but the M{sub s} values of the core-shell materials decrease with the amount of polyaniline (PAN) in the core-shell ferrite-polyaniline materials. The composite specimens of the core-shell ferrite-polyaniline and epoxide resin have bandwidth microwave absorption of the reflection lose -5 dB to -10 dB at the frequency between 4.5 GHz and 6.8 GHz were also observed by the network analyzer.

  12. Reservoir Characteristic of Famennian Deposits of the Solikamsk Depression

    Directory of Open Access Journals (Sweden)

    A. V. Plyusnin

    2015-06-01

    Full Text Available The article describes the reservoir rock properties of Famennian (Late Devonian reef carbonate strata obtained by core study at boreholes № 1-4 of the Sukharev oil field. Based on the results of detailed study of lithological features of productive strata, authors defined the structural types and composed their description. The characteristics of the porosity and permeability of oil-bearing beds were shown. In a result of studies, the structure and main lithotypes of Famennian portion of reservoir were determined that allowed predicting the spatial distribution of reservoir properties within oilfield area.

  13. Making an Ice Core.

    Science.gov (United States)

    Kopaska-Merkel, David C.

    1995-01-01

    Explains an activity in which students construct a simulated ice core. Materials required include only a freezer, food coloring, a bottle, and water. This hands-on exercise demonstrates how a glacier is formed, how ice cores are studied, and the nature of precision and accuracy in measurement. Suitable for grades three through eight. (Author/PVD)

  14. Methods to evaluate some reservoir characterization by means of the geophysical data in the strata of limestone and marl

    Directory of Open Access Journals (Sweden)

    V. M. Seidov

    2017-12-01

    Full Text Available As we know, the main goal of interpreting the materials of well logging, including the allocation of collectors and assessment of their saturation, are successfully achieved when the process of interpretation has a strong methodological support. This means, that it is justified by the necessary interpretational models and effective instructional techniques are used. They are based on structural and petrophysical models of reservoirs of the section investigated. The problem of studying the marl rocks with the help of the geophysical methods is not worked out properly. Many years of experience of studying limestone and marl rocks has made it possible to justify the optimal method of data interpretation of geophysical research wells in carbonate sections, which was represented by limestone and marl formations. A new method was developed to study marl rocks. It includes the following main studies: detection of reservoirs in the carbonate section according to the materials of geophysical studies of wells; determination of the geophysical parameters of each reservoir; assessment of the quality of well logging curves; introduction of amendments; selection of reference layers; the calculation of the relative double differencing parameters; the involvement of core data; identifying the lithological rock composition; the rationale for structural models of reservoirs; the definition of the block and of the total porosity; determination of argillaceous carbonate rocks; determination of the coefficient of water saturation of formations based on the type of the collector; setting a critical value for effective porosity, etc. This method was applied in the Eocene deposits of the Interfluve of the Kura and Iori, which is a promising object of hydrocarbons in Azerbaijan. The following conclusions have been made: this methodology successfully solves the problem of petrophysical characteristics of marl rocks; bad connection is observed between some of the

  15. Application of Integrated Reservoir Management and Reservoir Characterization to Optimize Infill Drillings. Annual technical progress report, June 13, 1996 to June 12, 1998

    Energy Technology Data Exchange (ETDEWEB)

    Nevans, Jerry W.; Blasingame, Tom; Doublet, Louis; Kelkar, Mohan; Freeman, George; Callard, Jeff; Moore, David; Davies, David; Vessell, Richard; Pregger, Brian; Dixon, Bill

    1999-04-27

    Infill drilling of wells on a uniform spacing, without regard to reservoir performance and characterization, does not optimize reservoir development because it fails to account for the complex nature of reservoir heterogeneities present in many low permeability reservoirs, and carbonate reservoirs in particular. New and emerging technologies, such as geostatistical modeling, rigorous decline curve analysis, reservoir rock typing, and special core analysis can be used to develop a 3-D simulation model for prediction of infill locations. Other technologies, such as inter-well injection tracers and magnetic flow conditioners, can also aid in the efficient evaluation and operation of both injection and producing wells. The purpose of this project was to demonstrate useful and cost effective methods of exploitation of the shallow shelf carbonate reservoirs of the Permian Basin located in West Texas.

  16. RESERVOIR CHARACTERIZATION OF UPPER DEVONIAN GORDON SANDSTONE, JACKSONBURG STRINGTOWN OIL FIELD, NORTHWESTERN WEST VIRGINIA

    Energy Technology Data Exchange (ETDEWEB)

    S. Ameri; K. Aminian; K.L. Avary; H.I. Bilgesu; M.E. Hohn; R.R. McDowell; D.L. Matchen

    2001-07-01

    The Jacksonburg-Stringtown oil field contained an estimated 88,500,000 barrels of oil in place, of which approximately 20,000,000 barrels were produced during primary recovery operations. A gas injection project, initiated in 1934, and a pilot waterflood, begun in 1981, yielded additional production from limited portions of the field. The pilot was successful enough to warrant development of a full-scale waterflood in 1990, involving approximately 8,900 acres in three units, with a target of 1,500 barrels of oil per acre recovery. Historical patterns of drilling and development within the field suggests that the Gordon reservoir is heterogeneous, and that detailed reservoir characterization is necessary for understanding well performance and addressing problems observed by the operators. The purpose of this work is to establish relationships among permeability, geophysical and other data by integrating geologic, geophysical and engineering data into an interdisciplinary quantification of reservoir heterogeneity as it relates to production. Conventional stratigraphic correlation and core description shows that the Gordon sandstone is composed of three parasequences, formed along the Late Devonian shoreline of the Appalachian Basin. The parasequences comprise five lithofacies, of which one includes reservoir sandstones. Pay sandstones were found to have permeabilities in core ranging from 10 to 200 mD, whereas non-pay sandstones have permeabilities ranging from below the level of instrumental detection to 5 mD; Conglomeratic zones could take on the permeability characteristics of enclosing materials, or could exhibit extremely low values in pay sandstone and high values in non-pay or low permeability pay sandstone. Four electrofacies based on a linear combination of density and scaled gamma ray best matched correlations made independently based on visual comparison of geophysical logs. Electrofacies 4 with relatively high permeability (mean value > 45 mD) was

  17. Freshwater reservoir effect variability in Northern Germany

    DEFF Research Database (Denmark)

    Philippsen, Bente; Heinemeier, Jan

    2012-01-01

    Kayhude at the river Alster and Schlamersdorf at the river Trave, both in Schleswig-Holstein, Northern Germany. Measurements on modern materials from these rivers may not give a single reservoir age correction that can be applied to archaeological samples, but they will show the order of magnitude...

  18. Anisotropy and spatial variation of relative permeability and lithologic character of Tensleep Sandstone reservoirs in the Bighorn and Wind River basins, Wyoming. Final technical report, September 15, 1993--October 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, T.L.

    1996-10-01

    This multidisciplinary study was designed to provide improvements in advanced reservoir characterization techniques. This goal was accomplished through: (1) an examination of the spatial variation and anisotropy of relative permeability in the Tensleep Sandstone reservoirs of Wyoming; (2) the placement of that variation and anisotropy into paleogeographic, and depositional regional frameworks; (3) the development of pore-system imagery techniques for the calculation of relative permeability; and (4) reservoir simulations testing the impact of relative permeability anisotropy and spatial variation on Tensleep Sandstone reservoir enhanced oil recovery. Concurrent efforts were aimed at understanding the spatial and dynamic alteration in sandstone reservoirs that is caused by rock-fluid interaction during CO{sub 2} enhanced oil recovery processes. The work focused on quantifying the interrelationship of fluid-rock interaction with lithologic characterization and with fluid characterization in terms of changes in chemical composition and fluid properties. This work establishes new criteria for the susceptibility of Tensleep Sandstone reservoirs to formation alteration that results in wellbore scale damage. This task was accomplished by flow experiments using core material; examination of regional trends in water chemistry; examination of local water chemistry trends the at field scale; and chemical modeling of both the experimental and reservoir systems.

  19. Effect of Various Treatment Modalities on Surface Characteristics and Shear Bond Strengths of Polyetheretherketone-Based Core Materials.

    Science.gov (United States)

    Çulhaoğlu, Ahmet Kürşat; Özkır, Serhat Emre; Şahin, Volkan; Yılmaz, Burak; Kılıçarslan, Mehmet Ali

    2017-11-13

    ), and silicoated PEEK surfaces (8.07 ± 2.54 MPa). Acetone-treated (5.98 ± 1.54 MPa) and untreated PEEK surfaces (5.09 ± 2.14 MPa) provided the lowest mean shear bond strengths. The highest mean shear bond strengths were observed for acid-etched PEEK surfaces, followed by laser-irradiated, airborne particle abraded, and silicoated PEEK surfaces providing similar mean shear bond strengths. Since shear bond strengths higher than 10 MPa are considered acceptable, acid etching, laser irradiation, and airborne particle abrasion of PEEK surfaces may be considered viable surface treatment modalities for the PEEK material tested. © 2017 by the American College of Prosthodontists.

  20. Optimising reservoir operation

    DEFF Research Database (Denmark)

    Ngo, Long le

    Anvendelse af optimeringsteknik til drift af reservoirer er blevet et væsentligt element i vandressource-planlægning og -forvaltning. Traditionelt har reservoirer været styret af heuristiske procedurer for udtag af vand, suppleret i en vis udstrækning af subjektive beslutninger. Udnyttelse af...... reservoirer involverer en lang række interessenter med meget forskellige formål (f.eks. kunstig vanding, vandkraft, vandforsyning mv.), og optimeringsteknik kan langt bedre lede frem til afbalancerede løsninger af de ofte modstridende interesser. Afhandlingen foreslår en række tiltag, hvormed traditionelle...... driftsstrategier kan erstattes af optimale strategier baseret på den nyeste udvikling indenfor computer-baserede beregninger. Hovedbidraget i afhandlingen er udviklingen af et beregningssystem, hvori en simuleringsmodel er koblet til en model for optimering af nogle udvalgte beslutningsvariable, der i særlig grad...

  1. Influence of core design, production technique, and material selection on fracture behavior of yttria-stabilized tetragonal zirconia polycrystal fixed dental prostheses produced using different multilayer techniques: split-file, over-pressing, and manually built-up veneers

    Science.gov (United States)

    Mahmood, Deyar Jallal Hadi; Linderoth, Ewa H; Wennerberg, Ann; Vult Von Steyern, Per

    2016-01-01

    Aim To investigate and compare the fracture strength and fracture mode in eleven groups of currently, the most commonly used multilayer three-unit all-ceramic yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) fixed dental prostheses (FDPs) with respect to the choice of core material, veneering material area, manufacturing technique, design of connectors, and radii of curvature of FDP cores. Materials and methods A total of 110 three-unit Y-TZP FDP cores with one intermediate pontic were made. The FDP cores in groups 1–7 were made with a split-file design, veneered with manually built-up porcelain, computer-aided design-on veneers, and over-pressed veneers. Groups 8–11 consisted of FDPs with a state-of-the-art design, veneered with manually built-up porcelain. All the FDP cores were subjected to simulated aging and finally loaded to fracture. Results There was a significant difference (Pveneering materials and techniques tested in the study, split-file, over-press, built-up porcelains, and glass–ceramics are, with a great safety margin, sufficient for clinical use both anteriorly and posteriorly. Analysis of the fracture pattern shows differences between the milled veneers and over-pressed or built-up veneers, where the milled ones show numerically more veneer cracks and the other groups only show complete connector fractures. PMID:26929667

  2. Experimental evaluation on the damages of different drilling modes to tight sandstone reservoirs

    Directory of Open Access Journals (Sweden)

    Gao Li

    2017-07-01

    Full Text Available The damages of different drilling modes to reservoirs are different in types and degrees. In this paper, the geologic characteristics and types of such damages were analyzed. Then, based on the relationship between reservoir pressure and bottom hole flowing pressure corresponding to different drilling modes, the experimental procedures on reservoir damages in three drilling modes (e.g. gas drilling, liquid-based underbalanced drilling and overbalanced drilling were designed. Finally, damage simulation experiments were conducted on the tight sandstone reservoir cores of the Jurassic Ahe Fm in the Tarim Basin and Triassic Xujiahe Fm in the central Sichuan Basin. It is shown that the underbalanced drilling is beneficial to reservoir protection because of its less damage on reservoir permeability, but it is, to some extent, sensitive to the stress and the empirical formula of stress sensitivity coefficient is obtained; and that the overbalanced drilling has more reservoir damages due to the invasion of solid and liquid phases. After the water saturation of cores rises to the irreducible water saturation, the decline of gas logging permeability speeds up and the damage degree of water lock increases. It is concluded that the laboratory experiment results of reservoir damage are accordant with the reservoir damage characteristics in actual drilling conditions. Therefore, this method reflects accurately the reservoir damage characteristics and can be used as a new experimental evaluation method on reservoir damage in different drilling modes.

  3. Evidence for an ancient osmium isotopic reservoir in Earth.

    Science.gov (United States)

    Meibom, Anders; Frei, Robert

    2002-04-19

    Iridosmine grains from placer deposits associated with peridotite-bearing ophiolites in the Klamath mountains have extremely radiogenic 186Os/188Os ratios and old Re-Os minimum ages, from 256 to 2644 million years. This indicates the existence of an ancient platinum group element reservoir with a supra-chondritic Pt/Os ratio. Such a ratio may be produced in the outer core as a result of inner core crystallization that fractionates Os from Pt. However, if the iridosmine Os isotopic compositions are a signature of the outer core, then the inner core must have formed very early, within several hundred million years after the accretion of Earth.

  4. Geothermal reservoir engineering

    CERN Document Server

    Grant, Malcolm Alister

    2011-01-01

    As nations alike struggle to diversify and secure their power portfolios, geothermal energy, the essentially limitless heat emanating from the earth itself, is being harnessed at an unprecedented rate.  For the last 25 years, engineers around the world tasked with taming this raw power have used Geothermal Reservoir Engineering as both a training manual and a professional reference.  This long-awaited second edition of Geothermal Reservoir Engineering is a practical guide to the issues and tasks geothermal engineers encounter in the course of their daily jobs. The bo

  5. Session: Reservoir Technology

    Energy Technology Data Exchange (ETDEWEB)

    Renner, Joel L.; Bodvarsson, Gudmundur S.; Wannamaker, Philip E.; Horne, Roland N.; Shook, G. Michael

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of five papers: ''Reservoir Technology'' by Joel L. Renner; ''LBL Research on the Geysers: Conceptual Models, Simulation and Monitoring Studies'' by Gudmundur S. Bodvarsson; ''Geothermal Geophysical Research in Electrical Methods at UURI'' by Philip E. Wannamaker; ''Optimizing Reinjection Strategy at Palinpinon, Philippines Based on Chloride Data'' by Roland N. Horne; ''TETRAD Reservoir Simulation'' by G. Michael Shook

  6. Experimental Study and Mathematical Modeling of Asphaltene Deposition Mechanism in Core Samples

    Directory of Open Access Journals (Sweden)

    Jafari Behbahani T.

    2015-11-01

    Full Text Available In this work, experimental studies were conducted to determine the effect of asphaltene deposition on the permeability reduction and porosity reduction of carbonate, sandstone and dolomite rock samples using an Iranian bottom hole live oil sample which is close to reservoir conditions, whereas in the majority of previous work, a mixture of recombined oil (a mixture of dead oil and associated gas was injected into a core sample which is far from reservoir conditions. The effect of the oil injection rate on asphaltene deposition and permeability reduction was studied. The experimental results showed that an increase in the oil injection flow rate can result in an increase in asphaltene deposition and permeability reduction. Also, it can be observed that at lower injection flow rates, a monotonic decrease in permeability of the rock samples can be attained upon increasing the injection flow rate, while at higher injection rates, after a decrease in rock permeability, an increasing trend is observed before a steady-state condition can be reached. The experimental results also showed that the rock type can affect the amount of asphaltene deposition, and the asphaltene deposition has different mechanisms in sandstone and carbonate core samples. It can be seen that the adsorption and plugging mechanisms have a more important role in asphaltene deposition in carbonate core samples than sandstone core samples. From the results, it can be observed that the pore volumes of the injected crude oil are higher for sandstone cores compared with the carbonate cores. Also, it can be inferred that three depositional types may take place during the crude oil injection, i.e., continuous deposition for low-permeability cores, slow, steady plugging for high-permeability cores and steady deposition for medium-permeability cores. It can be seen from the experimental results that damage to the core samples was found to increase when the production pressures were

  7. Crafts and gears used in reservoirs of Marathawada region, Maharashtra

    Directory of Open Access Journals (Sweden)

    S. G. Jetithor

    2013-09-01

    Full Text Available It was analyzed the fisheries arts in reservoirs of Marathawada region, Maharashtra, it was compared the different kinds of fisheries arts considering efectivity, materials, mode of use, and fisheries efforts for different sites.

  8. An Effective Reservoir Parameter for Seismic Characterization of Organic Shale Reservoir

    Science.gov (United States)

    Zhao, Luanxiao; Qin, Xuan; Zhang, Jinqiang; Liu, Xiwu; Han, De-hua; Geng, Jianhua; Xiong, Yineng

    2017-12-01

    Sweet spots identification for unconventional shale reservoirs involves detection of organic-rich zones with abundant porosity. However, commonly used elastic attributes, such as P- and S-impedances, often show poor correlations with porosity and organic matter content separately and thus make the seismic characterization of sweet spots challenging. Based on an extensive analysis of worldwide laboratory database of core measurements, we find that P- and S-impedances exhibit much improved linear correlations with the sum of volume fraction of organic matter and porosity than the single parameter of organic matter volume fraction or porosity. Importantly, from the geological perspective, porosity in conjunction with organic matter content is also directly indicative of the total hydrocarbon content of shale resources plays. Consequently, we propose an effective reservoir parameter (ERP), the sum of volume fraction of organic matter and porosity, to bridge the gap between hydrocarbon accumulation and seismic measurements in organic shale reservoirs. ERP acts as the first-order factor in controlling the elastic properties as well as characterizing the hydrocarbon storage capacity of organic shale reservoirs. We also use rock physics modeling to demonstrate why there exists an improved linear correlation between elastic impedances and ERP. A case study in a shale gas reservoir illustrates that seismic-derived ERP can be effectively used to characterize the total gas content in place, which is also confirmed by the production well.

  9. Rock Physics of Reservoir Rocks with Varying Pore Water Saturation and Pore Water Salinity

    OpenAIRE

    Katika, Konstantina; Fabricius, Ida Lykke

    2016-01-01

    Advanced waterflooding (injection of water with selective ions in reservoirs) is amethod of enhanced oil recovery (EOR) that has attracted the interest of oil and gas companies that exploit the Danish oil and gas reservoirs. This method has been applied successfully in oil reservoirs and in the Smart Water project performed in a laboratory scale in order to evaluate the EOR processes in selected core plugs. A major step towards this evaluation is to identify the composition of the injected wa...

  10. Materialism.

    Science.gov (United States)

    Melnyk, Andrew

    2012-05-01

    Materialism is nearly universally assumed by cognitive scientists. Intuitively, materialism says that a person's mental states are nothing over and above his or her material states, while dualism denies this. Philosophers have introduced concepts (e.g., realization and supervenience) to assist in formulating the theses of materialism and dualism with more precision, and distinguished among importantly different versions of each view (e.g., eliminative materialism, substance dualism, and emergentism). They have also clarified the logic of arguments that use empirical findings to support materialism. Finally, they have devised various objections to materialism, objections that therefore serve also as arguments for dualism. These objections typically center around two features of mental states that materialism has had trouble in accommodating. The first feature is intentionality, the property of representing, or being about, objects, properties, and states of affairs external to the mental states. The second feature is phenomenal consciousness, the property possessed by many mental states of there being something it is like for the subject of the mental state to be in that mental state. WIREs Cogn Sci 2012, 3:281-292. doi: 10.1002/wcs.1174 For further resources related to this article, please visit the WIREs website. Copyright © 2012 John Wiley & Sons, Ltd.

  11. unconventional natural gas reservoirs

    International Nuclear Information System (INIS)

    Correa G, Tomas F; Osorio, Nelson; Restrepo R, Dora P

    2009-01-01

    This work is an exploration about different unconventional gas reservoirs worldwide: coal bed methane, tight gas, shale gas and gas hydrate? describing aspects such as definition, reserves, production methods, environmental issues and economics. The overview also mentioned preliminary studies about these sources in Colombia.

  12. Parallel reservoir simulator computations

    International Nuclear Information System (INIS)

    Hemanth-Kumar, K.; Young, L.C.

    1995-01-01

    The adaptation of a reservoir simulator for parallel computations is described. The simulator was originally designed for vector processors. It performs approximately 99% of its calculations in vector/parallel mode and relative to scalar calculations it achieves speedups of 65 and 81 for black oil and EOS simulations, respectively on the CRAY C-90

  13. Mathematical simulation of oil reservoir properties

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, A. [Instituto Politecnico Nacional (SEPI-ESQIE-UPALM-IPN), Unidad Profesional Zacatenco, Laboratorio de Analisis Met., Edif. ' Z' y Edif. 6 planta baja., Mexico City c.p. 07300 (Mexico)], E-mail: adalop123@mailbanamex.com; Romero, A.; Chavez, F. [Instituto Politecnico Nacional (SEPI-ESQIE-UPALM-IPN), Unidad Profesional Zacatenco, Laboratorio de Analisis Met., Edif. ' Z' y Edif. 6 planta baja., Mexico City c.p. 07300 (Mexico); Carrillo, F. [Instituto Politecnico Nacional (CICATA-IPN, Altamira Tamaulipas) (Mexico); Lopez, S. [Instituto Mexicano del Petroleo - Molecular Engineering Researcher (Mexico)

    2008-11-15

    The study and computational representation of porous media properties are very important for many industries where problems of fluid flow, percolation phenomena and liquid movement and stagnation are involved, for example, in building constructions, ore processing, chemical industries, mining, corrosion sciences, etc. Nevertheless, these kinds of processes present a noneasy behavior to be predicted and mathematical models must include statistical analysis, fractal and/or stochastic procedures to do it. This work shows the characterization of sandstone berea core samples which can be found as a porous media (PM) in natural oil reservoirs, rock formations, etc. and the development of a mathematical algorithm for simulating the anisotropic characteristics of a PM based on a stochastic distribution of some of their most important properties like porosity, permeability, pressure and saturation. Finally a stochastic process is used again to simulated the topography of an oil reservoir.

  14. Actualistic and Geochemical Modeling of Reservoir Rock, CO2 and Formation Fluid Interaction, Citronelle Oil Field, Alabama

    Energy Technology Data Exchange (ETDEWEB)

    Weislogel, Amy [West Virginia Univ., Morgantown, WV (United States)

    2014-01-31

    This report includes description of the Citronelle field study area and the work carried out in the project to characterize the geology and composition of reservoir rock material and to collect an analyze the geochemical composition of produced fluid waters from the Citronelle field. Reservoir rock samples collected from well bore core were made into thin-sections and assessed for textural properties, including pore types and porosity distribution. Compositional framework grain modal data were collected via point-counting, and grain and cement mineralogy was assessed using SEM-EDS. Geochemistry of fluid samples is described and modeled using PHREEQC. Composition of rock and produced fluids were used as inputs for TOUGHREACT reactive transport modeling, which determined the rock-fluid system was in disequilibrium.

  15. Influence of core design, production technique, and material selection on fracture behavior of yttria-stabilized tetragonal zirconia polycrystal fixed dental prostheses produced using different multilayer techniques: split-file, over-pressing, and manually built-up veneers.

    Science.gov (United States)

    Mahmood, Deyar Jallal Hadi; Linderoth, Ewa H; Wennerberg, Ann; Vult Von Steyern, Per

    2016-01-01

    To investigate and compare the fracture strength and fracture mode in eleven groups of currently, the most commonly used multilayer three-unit all-ceramic yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) fixed dental prostheses (FDPs) with respect to the choice of core material, veneering material area, manufacturing technique, design of connectors, and radii of curvature of FDP cores. A total of 110 three-unit Y-TZP FDP cores with one intermediate pontic were made. The FDP cores in groups 1-7 were made with a split-file design, veneered with manually built-up porcelain, computer-aided design-on veneers, and over-pressed veneers. Groups 8-11 consisted of FDPs with a state-of-the-art design, veneered with manually built-up porcelain. All the FDP cores were subjected to simulated aging and finally loaded to fracture. There was a significant difference (Pveneering materials and techniques tested in the study, split-file, over-press, built-up porcelains, and glass-ceramics are, with a great safety margin, sufficient for clinical use both anteriorly and posteriorly. Analysis of the fracture pattern shows differences between the milled veneers and over-pressed or built-up veneers, where the milled ones show numerically more veneer cracks and the other groups only show complete connector fractures.

  16. Reservoir characteristics and control factors of Carboniferous volcanic gas reservoirs in the Dixi area of Junggar Basin, China

    Directory of Open Access Journals (Sweden)

    Ji'an Shi

    2017-02-01

    Full Text Available Field outcrop observation, drilling core description, thin-section analysis, SEM analysis, and geochemistry, indicate that Dixi area of Carboniferous volcanic rock gas reservoir belongs to the volcanic rock oil reservoir of the authigenic gas reservoir. The source rocks make contact with volcanic rock reservoir directly or by fault, and having the characteristics of near source accumulation. The volcanic rock reservoir rocks mainly consist of acidic rhyolite and dacite, intermediate andesite, basic basalt and volcanic breccia: (1 Acidic rhyolite and dacite reservoirs are developed in the middle-lower part of the structure, have suffered strong denudation effect, and the secondary pores have formed in the weathering and tectonic burial stages, but primary pores are not developed within the early diagenesis stage. Average porosity is only at 8%, and the maximum porosity is at 13.5%, with oil and gas accumulation showing poor performance. (2 Intermediate andesite and basic basalt reservoirs are mainly distributed near the crater, which resembles the size of and suggests a volcanic eruption. Primary pores are formed in the early diagenetic stage, secondary pores developed in weathering and erosion transformation stage, and secondary fractures formed in the tectonic burial stage. The average porosity is at 9.2%, and the maximum porosity is at 21.9%: it is of the high-quality reservoir types in Dixi area. (3 The volcanic breccia reservoir has the same diagenetic features with sedimentary rocks, but also has the same mineral composition with volcanic rock; rigid components can keep the primary porosity without being affected by compaction during the burial process. At the same time, the brittleness of volcanic breccia reservoir makes it easily fracture under the stress; internal fracture was developmental. Volcanic breccia developed in the structural high part and suffered a long-term leaching effect. The original pore-fracture combination also made

  17. Adsorption Properties of Chalk Reservoir Materials

    DEFF Research Database (Denmark)

    Okhrimenko, Denis

    Understanding adsorption energetics and wetting properties of calcium carbonate surfaces is essential for developing remediation strategies for aquifers, improving oil recovery, minimising risk in CO2 storage and optimising industrial processes. This PhD was focussed on comparing the vapour....../gas adsorption properties of synthetic calcium carbonate phases (calcite, vaterite and aragonite) with chalk, which is composed of biogenic calcite (>98%). In combination with data from nanotechniques, the results demonstrate the complexity of chalk behavior and the role of nanoscale clay particles. The results...

  18. Optimized Cellular Core for Rotorcraft, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Patz Materials and Technologies has developed, produced and tested, as part of the Phase-I SBIR, a new form of composite cellular core material, named Interply Core,...

  19. Efficacy of the core DNA barcodes in identifying processed and poorly conserved plant materials commonly used in South African traditional medicine

    Directory of Open Access Journals (Sweden)

    Ledile Mankga

    2013-12-01

    Full Text Available Medicinal plants cover a broad range of taxa, which may be phylogenetically less related but morphologically very similar. Such morphological similarity between species may lead to misidentification and inappropriate use. Also the substitution of a medicinal plant by a cheaper alternative (e.g. other non-medicinal plant species, either due to misidentification, or deliberately to cheat consumers, is an issue of growing concern. In this study, we used DNA barcoding to identify commonly used medicinal plants in South Africa. Using the core plant barcodes, matK and rbcLa, obtained from processed and poorly conserved materials sold at the muthi traditional medicine market, we tested efficacy of the barcodes in species discrimination. Based on genetic divergence, PCR amplification efficiency and BLAST algorithm, we revealed varied discriminatory potentials for the DNA barcodes. In general, the barcodes exhibited high discriminatory power, indicating their effectiveness in verifying the identity of the most common plant species traded in South African medicinal markets. BLAST algorithm successfully matched 61% of the queries against a reference database, suggesting that most of the information supplied by sellers at traditional medicinal markets in South Africa is correct. Our findings reinforce the utility of DNA barcoding technique in limiting false identification that can harm public health.

  20. Reservoir characterization of hydraulic flow units in heavy-oil reservoirs at Petromonagas, eastern Orinoco belt, Venezuela

    Energy Technology Data Exchange (ETDEWEB)

    Merletti, G.D.; Hewitt, N.; Barrios, F.; Vega, V.; Carias, J. [BP Exploration, Houston, TX (United States); Bueno, J.C.; Lopez, L. [PDVSA Petroleos de Venezuela SA, Caracas (Venezuela, Bolivarian Republic of)

    2009-07-01

    An accurate integrated reservoir description is necessary in extra-heavy oil prospects where pore throat geometries are the ultimate control on hydrocarbon primary recovery. The key element in producing accurate oil reservoir descriptions and improving productivity is to determine relationships between core-derived pore-throat parameters and log-derived macroscopic attributes. This paper described the use of the flow zone indicator technique (FZI) to identify hydraulic units within depositional facies. It focused on a petrophysical analysis aimed at improving the description of reservoir sandstones containing heavy or extra heavy oil in the eastern Orinoco belt in Venezuela. The Petromonagas license area contains large volumes of crude oil in-place with an API gravity of 8. Production comes primarily from the lowermost stratigraphic unit of the Oficina Formation, the Miocene Morichal Member. Facies analysis has revealed various depositional settings and core measurements depict a wide range in reservoir quality within specific depositional facies. The reservoir is divided into 4 different rock qualities and 5 associated non-reservoir rocks. The use of the FZI technique provides a better understanding of the relationship between petrophysical rock types and depositional facies. 4 refs., 4 tabs., 8 figs.

  1. Particle size analysis of some sidewall cores from KU-1 Well ...

    African Journals Online (AJOL)

    ) sidewall cores obtained from the reservoir sands of KU-1 Well, offshore Benin Basin, Nigeria. High resolution core images of the samples under simulated natural and ultraviolet lightning conditions revealed that seven of the samples were ...

  2. APPLICATION OF INTEGRATED RESERVOIR MANAGEMENT AND RESERVOIR CHARACTERIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Jack Bergeron; Tom Blasingame; Louis Doublet; Mohan Kelkar; George Freeman; Jeff Callard; David Moore; David Davies; Richard Vessell; Brian Pregger; Bill Dixon; Bryce Bezant

    2000-03-01

    Reservoir performance and characterization are vital parameters during the development phase of a project. Infill drilling of wells on a uniform spacing, without regard to characterization does not optimize development because it fails to account for the complex nature of reservoir heterogeneities present in many low permeability reservoirs, especially carbonate reservoirs. These reservoirs are typically characterized by: (1) large, discontinuous pay intervals; (2) vertical and lateral changes in reservoir properties; (3) low reservoir energy; (4) high residual oil saturation; and (5) low recovery efficiency. The operational problems they encounter in these types of reservoirs include: (1) poor or inadequate completions and stimulations; (2) early water breakthrough; (3) poor reservoir sweep efficiency in contacting oil throughout the reservoir as well as in the nearby well regions; (4) channeling of injected fluids due to preferential fracturing caused by excessive injection rates; and (5) limited data availability and poor data quality. Infill drilling operations only need target areas of the reservoir which will be economically successful. If the most productive areas of a reservoir can be accurately identified by combining the results of geological, petrophysical, reservoir performance, and pressure transient analyses, then this ''integrated'' approach can be used to optimize reservoir performance during secondary and tertiary recovery operations without resorting to ''blanket'' infill drilling methods. New and emerging technologies such as geostatistical modeling, rock typing, and rigorous decline type curve analysis can be used to quantify reservoir quality and the degree of interwell communication. These results can then be used to develop a 3-D simulation model for prediction of infill locations. The application of reservoir surveillance techniques to identify additional reservoir ''pay'' zones

  3. EXPLOITATION AND OPTIMIZATION OF RESERVOIR PERFORMANCE IN HUNTON FORMATION, OKLAHOMA

    Energy Technology Data Exchange (ETDEWEB)

    Mohan Kelkar

    2002-03-31

    The West Carney Field in Lincoln County, Oklahoma is one of few newly discovered oil fields in Oklahoma. Although profitable, the field exhibits several unusual characteristics. These include decreasing water-oil ratios, decreasing gas-oil ratios, decreasing bottomhole pressures during shut-ins in some wells, and transient behavior for water production in many wells. This report explains the unusual characteristics of West Carney Field based on detailed geological and engineering analyses. We propose a geological history that explains the presence of mobile water and oil in the reservoir. The combination of matrix and fractures in the reservoir explains the reservoir's flow behavior. We confirm our hypothesis by matching observed performance with a simulated model and develop procedures for correlating core data to log data so that the analysis can be extended to other, similar fields where the core coverage may be limited.

  4. Francais de base. Programme de 9 ans, materiel didactique: 4e, 5e et 6e annees (Core French. Nine-Year Study Program, Instructional Materials: 4th, 5th and 6th Grades).

    Science.gov (United States)

    Manitoba Dept. of Education, Winnipeg. Bureau of French Education.

    Official instructional materials for the first three years (grades 4-6) of the Manitoba Department of Education's core French language program consist of units in geography, weather and calendars, holidays, and music designed for each of the three instructional levels. The units on geography focus on Manitoba and Canada. Units on the calendar and…

  5. A hybrid waveguide cell for the dielectric properties of reservoir rocks

    International Nuclear Information System (INIS)

    Siggins, A F; Gunning, J; Josh, M

    2011-01-01

    A hybrid waveguide cell is described for broad-band measurements of the dielectric properties of hydrocarbon reservoir rocks. The cell is designed to operate in the radio frequency range of 1 MHz to 1 GHz. The waveguide consists of 50 Ω coaxial lines feeding into a central cylindrical section which contains the sample under test. The central portion of the waveguide acts as a circular waveguide and can accept solid core plugs of 38 mm diameter and lengths from 2 to 150 mm. The central section can also be used as a conventional coaxial waveguide when a central electrode with spring-loaded end collets is installed. In the latter mode the test samples are required to be in the form of hollow cylinders. An additional feature of the cell is that the central section is designed to telescope over a limited range of 1–2 mm with the application of an axial load. Effective pressures up to 35 MPa can be applied to the sample under the condition of uniaxial strain. The theoretical basis of the hybrid waveguide cell is discussed together with calibration results. Two reservoir rocks, a Donnybrook sandstone and a kaolin rich clay, are then tested in the cell, both as hollow cylinders in coaxial mode and in the form of solid core plugs. The complex dielectric properties of the two materials over the bandwidth of 1 MHz to 1 GHz are compared with the results of the two testing methods

  6. Optimized Cellular Core For Rotorcraft, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Patz Materials and Technologies proposes to develop a unique structural cellular core material to improve mechanical performance, reduce platform weight and lower...

  7. Historical deposition and fluxes of mercury in Narraguinnep Reservoir, southwestern Colorado, USA

    International Nuclear Information System (INIS)

    Gray, John E.; Fey, David L.; Holmes, Charles W.; Lasorsa, Brenda K.

    2005-01-01

    Narraguinnep Reservoir has been identified as containing fish with elevated Hg concentrations and has been posted with an advisory recommending against consumption of fish. There are presently no point sources of significant Hg contamination to this reservoir or its supply waters. To evaluate potential historical Hg sources and deposition of Hg to Narraguinnep Reservoir, the authors measured Hg concentrations in sediment cores collected from this reservoir. The cores were dated by the 137 Cs method and these dates were further refined by relating water supply basin hydrological records with core sedimentology. Rates of historical Hg flux were calculated (ng/cm 2 /a) based on the Hg concentrations in the cores, sediment bulk densities, and sedimentation rates. The flux of Hg found in Narraguinnep Reservoir increased by approximately a factor of 2 after about 1970. The 3 most likely sources of Hg to Narraguinnep Reservoir are surrounding bedrocks, upstream inactive Au-Ag mines, and several coal-fired electric power plants in the Four Corners region. Patterns of Hg flux do not support dominant Hg derivation from surrounding bedrocks or upstream mining sources. There are 14 coal-fired power plants within 320 km of Narraguinnep Reservoir that produce over 80 x 10 6 MWH of power and about 1640 kg-Hg/a are released through stack emissions, contributing significant Hg to the surrounding environment. Two of the largest power plants, located within 80 km of the reservoir, emit about 950 kg-Hg/a. Spatial and temporal patterns of Hg fluxes for sediment cores collected from Narraguinnep Reservoir suggest that the most likely source of Hg to this reservoir is from atmospheric emissions from the coal-fired electric power plants, the largest of which began operation in this region in the late-1960s and early 1970s

  8. Work reservoirs in thermodynamics

    Science.gov (United States)

    Anacleto, Joaquim

    2010-05-01

    We stress the usefulness of the work reservoir in the formalism of thermodynamics, in particular in the context of the first law. To elucidate its usefulness, the formalism is then applied to the Joule expansion and other peculiar and instructive experimental situations, clarifying the concepts of configuration and dissipative work. The ideas and discussions presented in this study are primarily intended for undergraduate students, but they might also be useful to graduate students, researchers and teachers.

  9. Reservoir Modeling of Carbonate on Fika Field: The Challenge to Capture the Complexity of Rock and Oil Types

    Directory of Open Access Journals (Sweden)

    Erawati Fitriyani Adji

    2014-09-01

    Full Text Available DOI: 10.17014/ijog.v1i2.181The carbonate on Fika Field has a special character, because it grew above a basement high with the thickness and internal character variation. To develop the field, a proper geological model which can be used in reservoir simulation was needed. This model has to represent the complexity of the rock type and the variety of oil types among the clusters. Creating this model was challenging due to the heterogeneity of the Baturaja Formation (BRF: Early Miocene reef, carbonate platform, and breccia conglomerate grew up above the basement with a variety of thickness and quality distributions. The reservoir thickness varies between 23 - 600 ft and 3D seismic frequency ranges from 1 - 80 Hz with 25 Hz dominant frequency. Structurally, the Fika Field has a high basement slope, which has an impact on the flow unit layering slope. Based on production data, each area shows different characteristics and performance: some areas have high water cut and low cumulative production. Oil properties from several clusters also vary in wax content. The wax content can potentially build up a deposit inside tubing and flow-line, resulted in a possible disturbance to the operation. Five well cores were analyzed, including thin section and XRD. Seven check-shot data and 3D seismic Pre-Stack Time Migration (PSTM were available with limited seismic resolution. A seismic analysis was done after well seismic tie was completed. This analysis included paleogeography, depth structure map, and distribution of reservoir and basement. Core and log data generated facies carbonate distribution and rock typing, defining properties for log analysis and permeability prediction for each zone. An Sw prediction for each well was created by J-function analysis. This elaborates capillary pressure from core data, so it is very similar to the real conditions. Different stages of the initial model were done i.e. scale-up properties, data analysis, variogram modeling

  10. Advantageous Reservoir Characterization Technology in Extra Low Permeability Oil Reservoirs

    Directory of Open Access Journals (Sweden)

    Yutian Luo

    2017-01-01

    Full Text Available This paper took extra low permeability reservoirs in Dagang Liujianfang Oilfield as an example and analyzed different types of microscopic pore structures by SEM, casting thin sections fluorescence microscope, and so on. With adoption of rate-controlled mercury penetration, NMR, and some other advanced techniques, based on evaluation parameters, namely, throat radius, volume percentage of mobile fluid, start-up pressure gradient, and clay content, the classification and assessment method of extra low permeability reservoirs was improved and the parameter boundaries of the advantageous reservoirs were established. The physical properties of reservoirs with different depth are different. Clay mineral variation range is 7.0%, and throat radius variation range is 1.81 μm, and start pressure gradient range is 0.23 MPa/m, and movable fluid percentage change range is 17.4%. The class IV reservoirs account for 9.56%, class II reservoirs account for 12.16%, and class III reservoirs account for 78.29%. According to the comparison of different development methods, class II reservoir is most suitable for waterflooding development, and class IV reservoir is most suitable for gas injection development. Taking into account the gas injection in the upper section of the reservoir, the next section of water injection development will achieve the best results.

  11. Co-reduction self-assembly of reduced graphene oxide nanosheets coated Cu2O sub-microspheres core-shell composites as lithium ion battery anode materials

    International Nuclear Information System (INIS)

    Xu, Yi-Tao; Guo, Ying; Song, Le-Xin; Zhang, Kai; Yuen, Matthew M.F.; Xu, Jian-Bin; Fu, Xian-Zhu; Sun, Rong; Wong, Ching-Ping

    2015-01-01

    Cuprous oxide (Cu 2 O) sub-microspheres @ reduced graphene oxide (rGO) nanosheets core-shell composites with 3D architecture are successfully fabricated by a one-step method through co-reduction of irregular cupric citrate and graphene oxide nanosheets at room temperature. Comparing to the bare Cu 2 O sub-microspheres and the simple physical mixture of Cu 2 O and rGO (Cu 2 O-rGO-M), the Cu 2 O@rGO electrodes demonstrate dramatically improved capacity, cyclic stability and rate capability as anode materials for lithium ion batteries. At a low current density of 100 mA∙g −1 , Cu 2 O@rGO electrodes deliver a discharge capacity of 534 mAh∙g −1 after 50 cycles, retaining 94% of the initial capacity. Under a higher current density of 1000 mA∙g −1 , Cu 2 O@rGO electrodes exhibit a discharge capacity of 181 mAh∙g −1 after 200 cycles, approximately 4 times larger than that of bare Cu 2 O sub-microsphere electrodes. The rate capacity retention of Cu 2 O@rGO electrode is 74% at 200 mA∙g −1 and 38% at 1000 mA∙g −1 relative to 100 mA∙g −1 , much better than that for Cu 2 O-rGO-M (52% and 34%) and bare Cu 2 O electrodes (13% and 3%,). The enhanced electrochemical performance for Cu 2 O@rGO might be ascribed to the rGO coating and 3D architecture. The outer coated rGO nanosheets could provide additional 3D conductive networks as well as serve as the buffer layers for accommodating the large volume change of the inner Cu 2 O sub-microspheres during the charge-discharge cycling

  12. Preparation of core-shell structure KClO4@Al/CuO Nanoenergetic material and enhancement of thermal behavior.

    Science.gov (United States)

    Yang, Fan; Kang, Xiaoli; Luo, Jiangshan; Yi, Zao; Tang, Yongjian

    2017-06-16

    In this paper, a solvent/non-solvent synthetic approach has been utilized in preparing a new nanoenergetic material KClO 4 @Al/CuO by coating Al/CuO nanocomposites particles with a layer of nanoscale oxidizer KClO 4 . The coating process and mechanism are discussed. The composites of Al/CuO are uniformly mixed by mechanical ball milling process and CuO acts as a catalytic metallic oxide. The ternary mixtures KClO 4 @Al/CuO were characterized by X-ray diffraction (XRD) and the results reveal that after ball-milling and chemical synthesis process, the phase compositions haven't changed. Scan electron microscopy (SEM) images show that these energetic nanocomposites consist of small clusters of Al/CuO that are in intimate contact with a continuous and clear-cut KClO 4 layer (100-400 nm). In a Scanning transmission electron microscopy (STEM) elemental map, high K/Cl intensity on the perimeter of the nanoparticles and high Cu/Al content in the interior powerfully demonstrated the KClO 4 @Al/CuO core-shell nanostructure. Electrical ignition experiments and pressure cell test prove that these nanoenergetic composites are more sensitive to ignition with much higher burning rate than traditional formulations (conventional counterparts). To quantify the enhancement of thermal behavior, Thermogravimetry (TG) and Differential scanning calorimetry (DSC) were performed and the results show that the burning rate of these energetic nanocomposites nearly tripled.

  13. Stability of earth dam with a vertical core

    Directory of Open Access Journals (Sweden)

    Orekhov Vyacheslav Valentinovich

    2016-01-01

    Full Text Available Earth dam with impervious element in the form of asphaltic concrete core is currently the most promising type of earth dams (due to simple construction technology and universal service properties of asphaltic concrete and is widely used in the world. However, experience in the construction and operation of high dams (above 160 m is not available, and their work is scarcely explored. In this regard, the paper discusses the results of computational prediction of the stress-strain state and stability of a high earth dam (256 m high with the core. The authors considered asphaltic concrete containing 7 % of bitumen as the material of the core. Gravel was considered as the material of resistant prisms. Design characteristics of the rolled asphaltic concrete and gravel were obtained from the processing of the results of triaxial tests. The calculations were performed using finite element method in elastoplastic formulation and basing on the phased construction of the dam and reservoir filling. The research shows, that the work of embankment dam with vertical core during filling of the reservoir is characterized by horizontal displacement of the lower resistant prism in the tailrace and the formation of a hard wedge prism descending along the core in the upper resistant prism. The key issue of the safety assessment is to determine the safety factor of the overall stability of the dam, for calculation of which the destruction of the earth dam is necessary, which can be done by reducing the strength properties of the dam materials. As a results of the calculations, the destruction of the dam occurs with a decrease in the strength characteristics of the materials of the dam by 2.5 times. The dam stability depends on the stability of the lower resistant prism. The destruction of its slope occurs on the classical circular-cylindrical surface. The presence of a potential collapse surface in the upper resistant prism (on the edges of the descending wedge does

  14. Reservoir Space Evolution of Volcanic Rocks in Deep Songliao Basin, China

    Science.gov (United States)

    Zheng, M.; Wu, X.; Zheng, M.; HU, J.; Wang, S.

    2015-12-01

    Recent years, large amount of natural gas has been discovered in volcanic rock of Lower Crataceous of Songliao basin. Volcanic reservoirs have become one of the important target reservoir types of eastern basin of China. In order to study the volcanic reservoirs, we need to know the main factors controlling the reservoir space. By careful obsercation on volcanic drilling core, casting thin sections and statistical analysis of petrophysical properties of volcanic reservoir in Songliao basin, it can be suggested that the igneous rock reservoir in Yingcheng formation of Lower Crataceous is composed of different rock types, such ad rohylite, rohylitic crystal tuff, autoclastic brecciation lava and so on. There are different reservoirs storage space in in various lithological igneous rocks, but they are mainly composed of primary stoma, secondary solution pores and fractures.The evolution of storage space can be divided into 3 stage: the pramary reservoir space,exogenic leaching process and burial diagenesis.During the evolution process, the reservoir space is effected by secondary minerals, tectonic movement and volcanic hydrothermal solution. The pore of volcanic reservoirs can be partially filled by secondary minerals, but also may be dissoluted by other chemical volcanic hydrothermal solution. Therefore, the favorable places for better-quality volcanic reservoirs are the near-crater facies of vocanic apparatus and dissolution zones on the high position of paleo-structures.

  15. Carbon isotope heterogeneities in deep Earth: Recycling of surface carbon or from core?

    Science.gov (United States)

    Satish-Kumar, Madhusoodhan

    2017-04-01

    Subduction of crustal materials, mantle melting and upwelling of deep mantle, in addition to a potential source from the core, largely controls the Earth's deep carbon cycle. Large variations in carbon isotopic composition between different reservoirs have been used widely to differentiate the source of carbon and to understand the carbon inventories and its recycling processes. However, how far high-temperature and hign-pressure conditions can affect the carbon isotope distribution, is a question still unanswered to clearly address the deep carbon cycle. I present here a review on carbon isotope fractionation processes in deep Earth and critically evaluate whether we can easily differentiate between surface carbon and deep carbon based on isotope characteristics. Recent experimental carbon isotope fractionation studies in the Fe-C system suggests that light carbon is selectively partition into metallic core during early magma ocean environment (Satish-Kumar et al., 2011). Furthermore, carbonate melts can be a medium for efficient crystallisation of diamonds in Earth's mantle (Palyanov et al., 2013). Rayleigh fractionation modelling based on fractionation suggests that core can be a reservoir of 12C enriched carbon and can itself form a reservoir which can cause heterogeneity in mantle carbon (Wood et al., 2013). In addition, high pressure experiments in the carbon-saturated model harzburgite system (Enstatite-Magnesite-Olivine-Graphite), carbonated silicate melting resulted in 13C enrichment in the carbon dissolved in the silicate melt relative to elemental graphite (Mizutani et al., 2014). 13C enrichment in carbonate melt were further confirmed in experiments where redox melting between olivine and graphite produced a carbonate melt as well as carbonate reduction experiments to form graphite. A third factor, still unconquered is the effect of pressure on isotope fractionation process. Theoretical studies as well as preliminary experimental studies have suggested

  16. Geothermal reservoir management

    Energy Technology Data Exchange (ETDEWEB)

    Scherer, C.R.; Golabi, K.

    1978-02-01

    The optimal management of a hot water geothermal reservoir was considered. The physical system investigated includes a three-dimensional aquifer from which hot water is pumped and circulated through a heat exchanger. Heat removed from the geothermal fluid is transferred to a building complex or other facility for space heating. After passing through the heat exchanger, the (now cooled) geothermal fluid is reinjected into the aquifer. This cools the reservoir at a rate predicted by an expression relating pumping rate, time, and production hole temperature. The economic model proposed in the study maximizes discounted value of energy transferred across the heat exchanger minus the discounted cost of wells, equipment, and pumping energy. The real value of energy is assumed to increase at r percent per year. A major decision variable is the production or pumping rate (which is constant over the project life). Other decision variables in this optimization are production timing, reinjection temperature, and the economic life of the reservoir at the selected pumping rate. Results show that waiting time to production and production life increases as r increases and decreases as the discount rate increases. Production rate decreases as r increases and increases as the discount rate increases. The optimal injection temperature is very close to the temperature of the steam produced on the other side of the heat exchanger, and is virtually independent of r and the discount rate. Sensitivity of the decision variables to geohydrological parameters was also investigated. Initial aquifer temperature and permeability have a major influence on these variables, although aquifer porosity is of less importance. A penalty was considered for production delay after the lease is granted.

  17. Experimental studies of low salinity water flooding in carbonate reservoirs: A new promising approach

    DEFF Research Database (Denmark)

    Zahid, Adeel; Shapiro, Alexander; Skauge, Arne

    2012-01-01

    Low salinity water flooding is well studied for sandstone reservoirs, both laboratory and field tests have showed improvement in the oil recovery in many cases. Up to very recently, the low salinity effect has been indeterminated for carbonates. Most recently, Saudi Aramco reported that substantial...... reservoirs. In this paper, we have experimentally investigated the oil recovery potential of low salinity water flooding for carbonate rocks. We used both reservoir carbonate and outcrop chalk core plugs. The flooding experiments were carried out initially with the seawater, and afterwards additional oil...... both at ambient and high temperature. No low salinity effect was observed for the reservoir carbonate core plug at the ambient temperature, but increase of the pressure drop over the core plug was detected. On the contrary, a significant increase in oil recovery was observed under low salinity flooding...

  18. Advances in photonic reservoir computing

    Science.gov (United States)

    Van der Sande, Guy; Brunner, Daniel; Soriano, Miguel C.

    2017-05-01

    We review a novel paradigm that has emerged in analogue neuromorphic optical computing. The goal is to implement a reservoir computer in optics, where information is encoded in the intensity and phase of the optical field. Reservoir computing is a bio-inspired approach especially suited for processing time-dependent information. The reservoir's complex and high-dimensional transient response to the input signal is capable of universal computation. The reservoir does not need to be trained, which makes it very well suited for optics. As such, much of the promise of photonic reservoirs lies in their minimal hardware requirements, a tremendous advantage over other hardware-intensive neural network models. We review the two main approaches to optical reservoir computing: networks implemented with multiple discrete optical nodes and the continuous system of a single nonlinear device coupled to delayed feedback.

  19. Encapsulated microsensors for reservoir interrogation

    Energy Technology Data Exchange (ETDEWEB)

    Scott, Eddie Elmer; Aines, Roger D.; Spadaccini, Christopher M.

    2016-03-08

    In one general embodiment, a system includes at least one microsensor configured to detect one or more conditions of a fluidic medium of a reservoir; and a receptacle, wherein the receptacle encapsulates the at least one microsensor. In another general embodiment, a method include injecting the encapsulated at least one microsensor as recited above into a fluidic medium of a reservoir; and detecting one or more conditions of the fluidic medium of the reservoir.

  20. Biological fundamentals of stocking the Zaporizhzhia (Dnipro reservoir with fish

    Directory of Open Access Journals (Sweden)

    O. Fedonenko

    2017-12-01

    Full Text Available Purpose. The main purpose is developing effective measures for stocking the Zaporizhzhia (Dnipro reservoir with valuable fish species by studying the biological and fishery aspects of the formation and exploitation of their commercial stocks. Methods. During the work, we used the generalized results of integrated hydrobiological studies performed in 2015-2017. Materials were collected in the Zaporizhzhia (Dnipro reservoir using standard fishing gears for fish sampling. Collection and processing of phyto-, zooplankton and zoobenthos samples were carried out using conventional hydrobiological methods. Calculation of fish seed amounts was carried out using classical fishery and ichthyological methods. Findings. The status of fish feed supply of the Zaporizhzhia (Dnipro reservoir and its production potential was determined. Based on the obtained data, we calculated the potential productivity of the reservoir. It was found that the reservoir had certain feed supply reserves allowing large scale stocking with the juveniles of commercial fish species. The recommended amounts of reservoir stocking in 2017 were calculated as follows: 570 thousand 1+ carp (weight 100-130 g; 1560 thousand 1+ silver carp (weight of 100-130 g; 400 thousand 1+ bighead carp (weight of 100-130 g; 220 thousand 1+ grass carp (weight of 100-130 g; 135 thousand 0+ tench (weight of 10-20 g; 83 thousand 0+ pike (weight of 100 g; 83 thousand 1+ pikeperch (weight 100 g. Scientific novelty. The presented results of the study of the state of fish feed supply in the reservoir allow stocking with the calculated amounts creating the bases of the rational use of aquatic bioresources with the preservation of the productive potential of commercial fish species exploited by commercial fishery in the Zaporizhzhia (Dnipro reservoir. Practical value. Stocking the reservoir with fish allows improving the overall ecological status of the reservoir and increasing fish productivity under the

  1. Ice Cores

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Records of past temperature, precipitation, atmospheric trace gases, and other aspects of climate and environment derived from ice cores drilled on glaciers and ice...

  2. Core BPEL

    DEFF Research Database (Denmark)

    Hallwyl, Tim; Højsgaard, Espen

    extensions. Combined with the fact that the language definition does not provide a formal semantics, it is an arduous task to work formally with the language (e.g. to give an implementation). In this paper we identify a core subset of the language, called Core BPEL, which has fewer and simpler constructs......, does not allow omissions, and does not contain ignorable elements. We do so by identifying syntactic sugar, including default values, and ignorable elements in WS-BPEL. The analysis results in a translation from the full language to the core subset. Thus, we reduce the effort needed for working...... formally with WS-BPEL, as one, without loss of generality, need only consider the much simpler Core BPEL. This report may also be viewed as an addendum to the WS-BPEL standard specification, which clarifies the WS-BPEL syntax and presents the essential elements of the language in a more concise way...

  3. Influence of core design, production technique, and material selection on fracture behavior of yttria-stabilized tetragonal zirconia polycrystal fixed dental prostheses produced using different multilayer techniques: split-file, over-pressing, and manually built-up veneers

    OpenAIRE

    Mahmood, Deyar Jallal Hadi; Linderoth, Ewa H; Wennerberg, Ann; Vult Von Steyern, Per

    2016-01-01

    Deyar Jallal Hadi Mahmood, Ewa H Linderoth, Ann Wennerberg, Per Vult Von Steyern Department of Prosthetic Dentistry, Faculty of Odontology, Malmö University, Malmö, Sweden Aim: To investigate and compare the fracture strength and fracture mode in eleven groups of currently, the most commonly used multilayer three-unit all-ceramic yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) fixed dental prostheses (FDPs) with respect to the choice of core material, veneering ma...

  4. Unconventional Tight Reservoirs Characterization with Nuclear Magnetic Resonance

    Science.gov (United States)

    Santiago, C. J. S.; Solatpour, R.; Kantzas, A.

    2017-12-01

    The increase in tight reservoir exploitation projects causes producing many papers each year on new, modern, and modified methods and techniques on estimating characteristics of these reservoirs. The most ambiguous of all basic reservoir property estimations deals with permeability. One of the logging methods that is advertised to predict permeability but is always met by skepticism is Nuclear Magnetic Resonance (NMR). The ability of NMR to differentiate between bound and movable fluids and providing porosity increased the capability of NMR as a permeability prediction technique. This leads to a multitude of publications and the motivation of a review paper on this subject by Babadagli et al. (2002). The first part of this presentation is dedicated to an extensive review of the existing correlation models for NMR based estimates of tight reservoir permeability to update this topic. On the second part, the collected literature information is used to analyze new experimental data. The data are collected from tight reservoirs from Canada, the Middle East, and China. A case study is created to apply NMR measurement in the prediction of reservoir characterization parameters such as porosity, permeability, cut-offs, irreducible saturations etc. Moreover, permeability correlations are utilized to predict permeability. NMR experiments were conducted on water saturated cores. NMR T2 relaxation times were measured. NMR porosity, the geometric mean relaxation time (T2gm), Irreducible Bulk Volume (BVI), and Movable Bulk Volume (BVM) were calculated. The correlation coefficients were computed based on multiple regression analysis. Results are cross plots of NMR permeability versus the independently measured Klinkenberg corrected permeability. More complicated equations are discussed. Error analysis of models is presented and compared. This presentation is beneficial in understanding existing tight reservoir permeability models. The results can be used as a guide for choosing

  5. Processing of reservoir data for diagenesis simulation; Traitement des donnees de reservoir en vue d`une simulation de la diagenese

    Energy Technology Data Exchange (ETDEWEB)

    Pelletier, I.

    1997-12-18

    Diagenetic minerals frequently damage reservoir permeability. A numerical model which couples chemical reactions and transport of dissolved elements can help to predict both location and magnitude of cementations. The present Ph.D. examines how can be applied such a modelling approach to a complex heterogeneous reservoir. Petrographical data from core samples are used as input data, or alternatively as controls for validating the modelling results. The measurements, acquired with dm-to-m spacing are too numerous to be integrated in a reactions-transport code. The usual up-scaling methods, called Homogenization, conserve only the fluid flow properties. A new method, called `Gathering` takes into account material transport balance. It is proposed in the first part of the dissertation. In the second part, an application of Gathering is done simulating illitization in the sub-arkosic sandstones of the Ness formation (Brent Group) in a North Sea field, Dunbar.. As a prerequisite, data accuracy is examined for a set of `routine measurements` (100 points counting on thin section, XR-diffractometry and gas porosity/permeability). (author) 60 refs.

  6. 49 CFR 230.72 - Testing main reservoirs.

    Science.gov (United States)

    2010-10-01

    ... the tensile strength of steel is unknown; and R = Inside radius of the reservoir in inches. (2... = certified working pressure in psi; S = 1/5 of the minimum specified tensile strength of the material in psi... strength of the material in psi, or 10,000 psi if the tensile strength is unknown; and R = Inside radius of...

  7. Reservoir Simulations of Low-Temperature Geothermal Reservoirs

    Science.gov (United States)

    Bedre, Madhur Ganesh

    The eastern United States generally has lower temperature gradients than the western United States. However, West Virginia, in particular, has higher temperature gradients compared to other eastern states. A recent study at Southern Methodist University by Blackwell et al. has shown the presence of a hot spot in the eastern part of West Virginia with temperatures reaching 150°C at a depth of between 4.5 and 5 km. This thesis work examines similar reservoirs at a depth of around 5 km resembling the geology of West Virginia, USA. The temperature gradients used are in accordance with the SMU study. In order to assess the effects of geothermal reservoir conditions on the lifetime of a low-temperature geothermal system, a sensitivity analysis study was performed on following seven natural and human-controlled parameters within a geothermal reservoir: reservoir temperature, injection fluid temperature, injection flow rate, porosity, rock thermal conductivity, water loss (%) and well spacing. This sensitivity analysis is completed by using ‘One factor at a time method (OFAT)’ and ‘Plackett-Burman design’ methods. The data used for this study was obtained by carrying out the reservoir simulations using TOUGH2 simulator. The second part of this work is to create a database of thermal potential and time-dependant reservoir conditions for low-temperature geothermal reservoirs by studying a number of possible scenarios. Variations in the parameters identified in sensitivity analysis study are used to expand the scope of database. Main results include the thermal potential of reservoir, pressure and temperature profile of the reservoir over its operational life (30 years for this study), the plant capacity and required pumping power. The results of this database will help the supply curves calculations for low-temperature geothermal reservoirs in the United States, which is the long term goal of the work being done by the geothermal research group under Dr. Anderson at

  8. Core mechanics and configuration behavior of advanced LMFBR core restraint concepts

    International Nuclear Information System (INIS)

    Fox, J.N.; Wei, B.C.

    1978-02-01

    Core restraint systems in LMFBRs maintain control of core mechanics and configuration behavior. Core restraint design is complex due to the close spacing between adjacent components, flux and temperature gradients, and irradiation-induced material property effects. Since the core assemblies interact with each other and transmit loads directly to the core restraint structural members, the core assemblies themselves are an integral part of the core restraint system. This paper presents an assessment of several advanced core restraint system and core assembly concepts relative to the expected performance of currently accepted designs. A recommended order for the development of the advanced concepts is also presented

  9. A review of reservoir desiltation

    DEFF Research Database (Denmark)

    Brandt, Anders

    2000-01-01

    physical geography, hydrology, desilation efficiency, reservoir flushing, density-current venting, sediment slucing, erosion pattern, downstream effects, flow characteristics, sedimentation......physical geography, hydrology, desilation efficiency, reservoir flushing, density-current venting, sediment slucing, erosion pattern, downstream effects, flow characteristics, sedimentation...

  10. Reservoir sedimentation; a literature survey

    NARCIS (Netherlands)

    Sloff, C.J.

    1991-01-01

    A survey of literature is made on reservoir sedimentation, one of the most threatening processes for world-wide reservoir performance. The sedimentation processes, their impacts, and their controlling factors are assessed from a hydraulic engineering point of view with special emphasis on

  11. FRACTURED PETROLEUM RESERVOIRS

    Energy Technology Data Exchange (ETDEWEB)

    Abbas Firoozabadi

    1999-06-11

    The four chapters that are described in this report cover a variety of subjects that not only give insight into the understanding of multiphase flow in fractured porous media, but they provide also major contribution towards the understanding of flow processes with in-situ phase formation. In the following, a summary of all the chapters will be provided. Chapter I addresses issues related to water injection in water-wet fractured porous media. There are two parts in this chapter. Part I covers extensive set of measurements for water injection in water-wet fractured porous media. Both single matrix block and multiple matrix blocks tests are covered. There are two major findings from these experiments: (1) co-current imbibition can be more efficient than counter-current imbibition due to lower residual oil saturation and higher oil mobility, and (2) tight fractured porous media can be more efficient than a permeable porous media when subjected to water injection. These findings are directly related to the type of tests one can perform in the laboratory and to decide on the fate of water injection in fractured reservoirs. Part II of Chapter I presents modeling of water injection in water-wet fractured media by modifying the Buckley-Leverett Theory. A major element of the new model is the multiplication of the transfer flux by the fractured saturation with a power of 1/2. This simple model can account for both co-current and counter-current imbibition and computationally it is very efficient. It can be orders of magnitude faster than a conventional dual-porosity model. Part II also presents the results of water injection tests in very tight rocks of some 0.01 md permeability. Oil recovery from water imbibition tests from such at tight rock can be as high as 25 percent. Chapter II discusses solution gas-drive for cold production from heavy-oil reservoirs. The impetus for this work is the study of new gas phase formation from in-situ process which can be significantly

  12. Reservoir engineering and hydrogeology

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    Summaries are included which show advances in the following areas: fractured porous media, flow in single fractures or networks of fractures, hydrothermal flow, hydromechanical effects, hydrochemical processes, unsaturated-saturated systems, and multiphase multicomponent flows. The main thrust of these efforts is to understand the movement of mass and energy through rocks. This has involved treating fracture rock masses in which the flow phenomena within both the fractures and the matrix must be investigated. Studies also address the complex coupling between aspects of thermal, hydraulic, and mechanical processes associated with a nuclear waste repository in a fractured rock medium. In all these projects, both numerical modeling and simulation, as well as field studies, were employed. In the theoretical area, a basic understanding of multiphase flow, nonisothermal unsaturated behavior, and new numerical methods have been developed. The field work has involved reservoir testing, data analysis, and case histories at a number of geothermal projects

  13. Chalk as a reservoir

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke

    basin, so stylolite formation in the chalk is controlled by effective burial stress. The stylolites are zones of calcite dissolution and probably are the source of calcite for porefilling cementation which is typical in water zone chalk and also affect the reservoirs to different extent. The relatively...... 50% calcite, leaving the remaining internal surface to the fine grained silica and clay. The high specific surface of these components causes clay- and silica rich intervals to have high irreducible water saturation. Although chalks typically are found to be water wet, chalk with mixed wettability...... stabilizes chemically by recrystallization. This process requires energy and is promoted by temperature. This recrystallization in principle does not influence porosity, but only specific surface, which decreases during recrystallization, causing permeability to increase. The central North Sea is a warm...

  14. Pacifiers: a microbial reservoir.

    Science.gov (United States)

    Comina, Elodie; Marion, Karine; Renaud, François N R; Dore, Jeanne; Bergeron, Emmanuelle; Freney, Jean

    2006-12-01

    The permanent contact between the nipple part of pacifiers and the oral microflora offers ideal conditions for the development of biofilms. This study assessed the microbial contamination on the surface of 25 used pacifier nipples provided by day-care centers. Nine were made of silicone and 16 were made of latex. The biofilm was quantified using direct staining and microscopic observations followed by scraping and microorganism counting. The presence of a biofilm was confirmed on 80% of the pacifier nipples studied. This biofilm was mature for 36% of them. Latex pacifier nipples were more contaminated than silicone ones. The two main genera isolated were Staphylococcus and Candida. Our results confirm that nipples can be seen as potential reservoirs of infections. However, pacifiers do have some advantages; in particular, the potential protection they afford against sudden infant death syndrome. Strict rules of hygiene and an efficient antibiofilm cleaning protocol should be established to answer the worries of parents concerning the safety of pacifiers.

  15. Variation of magnetic properties of toroidal cores with magnetizing frequency

    International Nuclear Information System (INIS)

    Derebasi, N.; Rygal, R.; Moses, A.J.; Fox, D.

    2000-01-01

    AC magnetic properties of toroidal cores made from six different soft magnetic materials were measured. A solid steel core exhibited the highest remanance, coercivity and core loss as expected whereas a nanocrystalline core had the lowest remanance of the cores tested. Increase in dynamic core loss with frequency in steel particle and iron powder cores was low compared with the other cores but was low in permeability

  16. Advanced Reservoir Characterization and Evaluation of C02 Gravity Drainage in the Naturally Fractured Sprayberry Trend Area

    Energy Technology Data Exchange (ETDEWEB)

    David S. Schechter

    1998-04-30

    The objective is to assess the economic feasibility of CO2 flooding of the naturally fractured Straberry Trend Area in west Texas. Research is being conducted in the extensive characterization of the reservoirs, the experimental studies of crude oil/brine/rock (COBR) interaction in the reservoirs, the analytical and numerical simulation of Spraberry reservoirs, and the experimental investigations on CO2 gravity drainage in Spraberry whole cores.

  17. Advances in photonic reservoir computing

    Directory of Open Access Journals (Sweden)

    Van der Sande Guy

    2017-05-01

    Full Text Available We review a novel paradigm that has emerged in analogue neuromorphic optical computing. The goal is to implement a reservoir computer in optics, where information is encoded in the intensity and phase of the optical field. Reservoir computing is a bio-inspired approach especially suited for processing time-dependent information. The reservoir’s complex and high-dimensional transient response to the input signal is capable of universal computation. The reservoir does not need to be trained, which makes it very well suited for optics. As such, much of the promise of photonic reservoirs lies in their minimal hardware requirements, a tremendous advantage over other hardware-intensive neural network models. We review the two main approaches to optical reservoir computing: networks implemented with multiple discrete optical nodes and the continuous system of a single nonlinear device coupled to delayed feedback.

  18. Microparticles obtained by complex coacervation: influence of the type of reticulation and the drying process on the release of the core material

    Directory of Open Access Journals (Sweden)

    Izabela Dutra Alvim

    2010-12-01

    Full Text Available Microparticles obtained by complex coacervation were crosslinked with glutaraldehyde or with transglutaminase and dried using freeze drying or spray drying. Moist samples presented Encapsulation Efficiency (%EE higher than 96%. The mean diameters ranged from 43.7 ± 3.4 to 96.4 ± 10.3 µm for moist samples, from 38.1 ± 5.36 to 65.2 ± 16.1 µm for dried samples, and from 62.5 ± 7.5 to 106.9 ± 26.1 µm for rehydrated microparticles. The integrity of the particles without crosslinking was maintained when freeze drying was used. After spray drying, only crosslinked samples were able to maintain the wall integrity. Microparticles had a round shape and in the case of dried samples rugged walls apparently without cracks were observed. Core distribution inside the particles was multinuclear and homogeneous and core release was evaluated using anhydrous ethanol. Moist particles crosslinked with glutaraldehyde at the concentration of 1.0 mM.g-1 protein (ptn, were more efficient with respect to the core retention compared to 0.1 mM.g-1 ptn or those crosslinked with transglutaminase (10 U.g-1 ptn. The drying processes had a strong influence on the core release profile reducing the amount released to all dry samples

  19. MULTIDISCIPLINARY IMAGING OF ROCK PROPERTIES IN CARBONATE RESERVOIRS FOR FLOW-UNIT TARGETING

    Energy Technology Data Exchange (ETDEWEB)

    Stephen C. Ruppel

    2004-07-20

    Our analysis and imaging of reservoir properties at the Fullerton Clear Fork field (Figure 1) is in its final stages. Major accomplishments during the past 6 months include: (1) characterization of facies and cyclicity in cores, (2) correlation of cycles and sequences using core-calibrated wireline logs, (3) calculation and modeling of wireline porosity, (4) analysis of new cores for conventional and special core analysis data, (5) construction of full-field reservoir model, and (6) revision of 3D seismic inversion of reservoir porosity and permeability. One activity has been eliminated from the originally proposed tasks. Task 3 (Characterization and Modeling of Rock Mechanics and Fractures) has been deleted because we have determined that fractures are not significant contributing in the reservoir under study. A second project extension has been asked for to extend the project until 7/31/04. Remaining project activities are: (1) interpretation and synthesis of fieldwide data, (2) preparation of 3D virtual reality demonstrations of reservoir model and attributes, (3) transfer of working data sets to the operator for reservoir implementation and decision-making, and (4) preparation and distribution of final reports.

  20. Gravity observations for hydrocarbon reservoir monitoring

    NARCIS (Netherlands)

    Glegola, M.A.

    2013-01-01

    In this thesis the added value of gravity observations for hydrocarbon reservoir monitoring and characterization is investigated. Reservoir processes and reservoir types most suitable for gravimetric monitoring are identified. Major noise sources affecting time-lapse gravimetry are analyzed. The

  1. New concept of damage evaluation method for core internal materials considering radiation induced stress relaxation (1). Experiments and modeling of radiation effects

    International Nuclear Information System (INIS)

    Miwa, Yukio; Kondo, Keietsu; Okubo, Nariaki; Kaji, Yoshiyuki; Tsukada, Takashi

    2009-01-01

    In order to build the new concept of material damage evaluation method, synergistic effect of radiation and residual stress on material degradation was estimated experimentally, and the effect of radiation induced stress relaxation on retardation of material degradation was observed. (author)

  2. Coring apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Mount, W.W.

    1967-11-14

    This invention relates to coring equipment and has special reference to such as are intended to be driven or otherwise inserted into sand or other loose formations to obtain a true sample of the formation. The device includes a plurality of elongated angular members positioned to form an elongated core receptacle between them. A plurality of links are each pivotally mounted at each end on an adjacent member to hold the members in spaced-apart relation in one position. The receptable is driven into the sand, and the members are moved toward one another when they are longitudinally moved with respect to one another to close the receptable. (3 claims)

  3. Analysis of real-time reservoir monitoring : reservoirs, strategies, & modeling.

    Energy Technology Data Exchange (ETDEWEB)

    Mani, Seethambal S.; van Bloemen Waanders, Bart Gustaaf; Cooper, Scott Patrick; Jakaboski, Blake Elaine; Normann, Randy Allen; Jennings, Jim (University of Texas at Austin, Austin, TX); Gilbert, Bob (University of Texas at Austin, Austin, TX); Lake, Larry W. (University of Texas at Austin, Austin, TX); Weiss, Chester Joseph; Lorenz, John Clay; Elbring, Gregory Jay; Wheeler, Mary Fanett (University of Texas at Austin, Austin, TX); Thomas, Sunil G. (University of Texas at Austin, Austin, TX); Rightley, Michael J.; Rodriguez, Adolfo (University of Texas at Austin, Austin, TX); Klie, Hector (University of Texas at Austin, Austin, TX); Banchs, Rafael (University of Texas at Austin, Austin, TX); Nunez, Emilio J. (University of Texas at Austin, Austin, TX); Jablonowski, Chris (University of Texas at Austin, Austin, TX)

    2006-11-01

    The project objective was to detail better ways to assess and exploit intelligent oil and gas field information through improved modeling, sensor technology, and process control to increase ultimate recovery of domestic hydrocarbons. To meet this objective we investigated the use of permanent downhole sensors systems (Smart Wells) whose data is fed real-time into computational reservoir models that are integrated with optimized production control systems. The project utilized a three-pronged approach (1) a value of information analysis to address the economic advantages, (2) reservoir simulation modeling and control optimization to prove the capability, and (3) evaluation of new generation sensor packaging to survive the borehole environment for long periods of time. The Value of Information (VOI) decision tree method was developed and used to assess the economic advantage of using the proposed technology; the VOI demonstrated the increased subsurface resolution through additional sensor data. Our findings show that the VOI studies are a practical means of ascertaining the value associated with a technology, in this case application of sensors to production. The procedure acknowledges the uncertainty in predictions but nevertheless assigns monetary value to the predictions. The best aspect of the procedure is that it builds consensus within interdisciplinary teams The reservoir simulation and modeling aspect of the project was developed to show the capability of exploiting sensor information both for reservoir characterization and to optimize control of the production system. Our findings indicate history matching is improved as more information is added to the objective function, clearly indicating that sensor information can help in reducing the uncertainty associated with reservoir characterization. Additional findings and approaches used are described in detail within the report. The next generation sensors aspect of the project evaluated sensors and packaging

  4. Application of Advanced Reservoir Characterization, Simulation, and Production Optimization Strategies to Maximize Recovery in Slope and Basin Clastic Reservoirs, West Texas (Delaware Basin)

    Energy Technology Data Exchange (ETDEWEB)

    Dutton, S.P.; Flanders, W.A.; Guzman, J.I.; Zirczy, H.

    1999-06-08

    The objective of this Class III project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost-effective way to recover a higher percentage of the original oil in place through geologically based field development. This year the project focused on reservoir characterization of the East Ford unit, a representative Delaware Mountain Group field that produces from the upper Bell Canyon Formation (Ramsey Sandstone). The field, discovered in 1960, is operated by Orla Petco, Inc., as the East Ford unit; it contained an estimated 19.8 million barrels (MMbbl) of original oil in place. Petrophysical characterization of the East Ford unit was accomplished by integrating core and log data and quantifying petrophysical properties from wireline logs. Most methods of petrophysical analysis that had been developed during an earlier study of the Ford Geraldine unit were successfully transferred to the East Ford unit. The approach that was used to interpret water saturation from resistivity logs, however, had to be modified because in some East Ford wells the log-calculated water saturation was too high and inconsistent with observations made during the actual production. Log-porosity to core-porosity transforms and core-porosity to core-permeability transforms were derived from the East Ford reservoir. The petrophysical data were used to map porosity, permeability, net pay, water saturation, mobil-oil saturation, and other reservoir properties.

  5. Well testing in gas hydrate reservoirs

    OpenAIRE

    Kome, Melvin Njumbe

    2015-01-01

    Reservoir testing and analysis are fundamental tools in understanding reservoir hydraulics and hence forecasting reservoir responses. The quality of the analysis is very dependent on the conceptual model used in investigating the responses under different flowing conditions. The use of reservoir testing in the characterization and derivation of reservoir parameters is widely established, especially in conventional oil and gas reservoirs. However, with depleting conventional reserves, the ...

  6. Influence of core design, production technique, and material selection on fracture behavior of yttria-stabilized tetragonal zirconia polycrystal fixed dental prostheses produced using different multilayer techniques: split-file, over-pressing, and manually built-up veneers

    Directory of Open Access Journals (Sweden)

    Mahmood DJH

    2016-02-01

    Full Text Available Deyar Jallal Hadi Mahmood, Ewa H Linderoth, Ann Wennerberg, Per Vult Von Steyern Department of Prosthetic Dentistry, Faculty of Odontology, Malmö University, Malmö, Sweden Aim: To investigate and compare the fracture strength and fracture mode in eleven groups of currently, the most commonly used multilayer three-unit all-ceramic yttria-stabilized tetragonal zirconia polycrystal (Y-TZP fixed dental prostheses (FDPs with respect to the choice of core material, veneering material area, manufacturing technique, design of connectors, and radii of curvature of FDP cores. Materials and methods: A total of 110 three-unit Y-TZP FDP cores with one intermediate pontic were made. The FDP cores in groups 1–7 were made with a split-file design, veneered with manually built-up porcelain, computer-aided design-on veneers, and over-pressed veneers. Groups 8–11 consisted of FDPs with a state-of-the-art design, veneered with manually built-up porcelain. All the FDP cores were subjected to simulated aging and finally loaded to fracture. Results: There was a significant difference (P<0.05 between the core designs, but not between the different types of Y-TZP materials. The split-file designs with VITABLOCS® (1,806±165 N and e.max® ZirPress (1,854±115 N and the state-of-the-art design with VITA VM® 9 (1,849±150 N demonstrated the highest mean fracture values. Conclusion: The shape of a split-file designed all-ceramic reconstruction calls for a different dimension protocol, compared to traditionally shaped ones, as the split-file design leads to sharp approximal indentations acting as fractural impressions, thus decreasing the overall strength. The design of a framework is a crucial factor for the load bearing capacity of an all-ceramic FDP. The state-of-the-art design is preferable since the split-file designed cores call for a cross-sectional connector area at least 42% larger, to have the same load bearing capacity as the state-of-the-art designed

  7. Superconducting tin core fiber

    Energy Technology Data Exchange (ETDEWEB)

    Homa, Daniel; Liang, Yongxuan; Hill, Cary; Kaur, Gurbinder; Pickrell, Gary [Virginia Polytechnic Institute and State University, Department of Materials Science and Engineering, Blacksburg, VA (United States)

    2014-11-13

    In this study, we demonstrated superconductivity in a fiber with a tin core and fused silica cladding. The fibers were fabricated via a modified melt-draw technique and maintained core diameters ranging from 50-300 microns and overall diameters of 125-800 microns. Superconductivity of this fiber design was validated via the traditional four-probe test method in a bath of liquid helium at temperatures on the order of 3.8 K. The synthesis route and fiber design are perquisites to ongoing research dedicated all-fiber optoelectronics and the relationships between superconductivity and the material structures, as well as corresponding fabrication techniques. (orig.)

  8. Superconducting tin core fiber

    International Nuclear Information System (INIS)

    Homa, Daniel; Liang, Yongxuan; Hill, Cary; Kaur, Gurbinder; Pickrell, Gary

    2015-01-01

    In this study, we demonstrated superconductivity in a fiber with a tin core and fused silica cladding. The fibers were fabricated via a modified melt-draw technique and maintained core diameters ranging from 50-300 microns and overall diameters of 125-800 microns. Superconductivity of this fiber design was validated via the traditional four-probe test method in a bath of liquid helium at temperatures on the order of 3.8 K. The synthesis route and fiber design are perquisites to ongoing research dedicated all-fiber optoelectronics and the relationships between superconductivity and the material structures, as well as corresponding fabrication techniques. (orig.)

  9. Sediment Characteristics of Tennessee Streams and Reservoirs

    National Research Council Canada - National Science Library

    Trimble, Stanley W; Carey, William P

    1984-01-01

    Suspended-sediment and reservoir sedimentation data have been analyzed to determine sediment yields and transport characteristics of Tennessee streams Data from 31 reservoirs plus suspended-sediment...

  10. Changes to the Bakomi Reservoir

    Directory of Open Access Journals (Sweden)

    Kubinský Daniel

    2014-08-01

    Full Text Available This article is focused on the analysis and evaluation of the changes of the bottom of the Bakomi reservoir, the total volume of the reservoir, ecosystems, as well as changes in the riparian zone of the Bakomi reservoir (situated in the central Slovakia. Changes of the water component of the reservoir were subject to the deposition by erosion-sedimentation processes, and were identifed on the basis of a comparison of the present relief of the bottom of reservoir obtained from feld measurements (in 2011 with the relief measurements of the bottom obtained from the 1971 historical maps, (i.e. over a period of 40 years. Changes of landscape structures of the riparian zone have been mapped for the time period of 1949–2013; these changes have been identifed with the analysis of ortophotomaps and the feld survey. There has been a signifcant rise of disturbed shores with low herb grassland. Over a period of 40 years, there has been a deposition of 667 m3 of sediments. The results showed that there were no signifcant changes in the local ecosystems of the Bakomi reservoir in comparison to the other reservoirs in the vicinity of Banská Štiavnica.

  11. A reservoir simulation approach for modeling of naturally fractured reservoirs

    Directory of Open Access Journals (Sweden)

    H. Mohammadi

    2012-12-01

    Full Text Available In this investigation, the Warren and Root model proposed for the simulation of naturally fractured reservoir was improved. A reservoir simulation approach was used to develop a 2D model of a synthetic oil reservoir. Main rock properties of each gridblock were defined for two different types of gridblocks called matrix and fracture gridblocks. These two gridblocks were different in porosity and permeability values which were higher for fracture gridblocks compared to the matrix gridblocks. This model was solved using the implicit finite difference method. Results showed an improvement in the Warren and Root model especially in region 2 of the semilog plot of pressure drop versus time, which indicated a linear transition zone with no inflection point as predicted by other investigators. Effects of fracture spacing, fracture permeability, fracture porosity, matrix permeability and matrix porosity on the behavior of a typical naturally fractured reservoir were also presented.

  12. Direct hydrocarbon exploration and gas reservoir development technology

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Young Hoon; Oh, Jae Ho; Jeong, Tae Jin [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of)] [and others

    1995-12-01

    In order to enhance the capability of petroleum exploration and development techniques, three year project (1994 - 1997) was initiated on the research of direct hydrocarbon exploration and gas reservoir development. This project consists of four sub-projects. (1) Oil(Gas) - source rock correlation technique: The overview of bio-marker parameters which are applicable to hydrocarbon exploration has been illustrated. Experimental analysis of saturated hydrocarbon and bio-markers of the Pohang E and F core samples has been carried out. (2) Study on surface geochemistry and microbiology for hydrocarbon exploration: the test results of the experimental device for extraction of dissolved gases from water show that the device can be utilized for the gas geochemistry of water. (3) Development of gas and gas condensate reservoirs: There are two types of reservoir characterization. For the reservoir formation characterization, calculation of conditional simulation was compared with that of unconditional simulation. In the reservoir fluid characterization, phase behavior calculations revealed that the component grouping is more important than the increase of number of components. (4) Numerical modeling of seismic wave propagation and full waveform inversion: Three individual sections are presented. The first one is devoted to the inversion theory in general sense. The second and the third sections deal with the frequency domain pseudo waveform inversion of seismic reflection data and refraction data respectively. (author). 180 refs., 91 figs., 60 tabs.

  13. Electrochemical behaviors of a wearable woven textile Li-ion battery consisting of a core and wound electrode fibers coated with active materials

    Science.gov (United States)

    Kim, C.; Bang, S.; Zhou, D.; Yun, S.

    2017-04-01

    A new fiber-type Li-ion battery that consists of carbon nanotube fibers deposited with active materials has been developed and tested. The active materials, LiMn2O4 and Li4Ti5O12, were deposited on the surface of carbon nanotube fibers in order to use as electrodes. Tensile strength of the CNT fibers with active material was measured by tensile tests to investigate the mechanical characteristics. Electrochemical property is also measured by a battery tester during charging and discharging. The results show that current discharge capacity is about 25 mAh/g between 3.0 V and 4.2 V. That means the fiber with active materials is good for an anode electrode. Mathematical material models considering the lithium concentration and the length of Li-C bond have been established in order to predict the effective elastic modulus of electrode composite materials.

  14. THE SURDUC RESERVOIR (ROMANIA

    Directory of Open Access Journals (Sweden)

    Niculae Iulian TEODORESCU

    2008-06-01

    Full Text Available The Surduc reservoir was projected to ensure more water when water is scarce and to thus provide especially the city Timisoara, downstream of it with water.The accumulation is placed on the main affluent of the Bega river, Gladna in the upper part of its watercourse.The dam behind which this accumulation was created is of a frontal type made of enrochements with a masque made of armed concrete on the upstream part and protected/sustained by grass on the downstream. The dam is 130m long on its coping and a constructed height of 34 m. It is also endowed with spillway for high water and two bottom outlets formed of two conduits, at the end of which is the microplant. The second part of my paper deals with the hydrometric analysis of the Accumulation Surduc and its impact upon the flow, especially the maximum run-off. This influence is exemplified through the high flood from the 29th of July 1980, the most significant flood recorded in the basin with an apparition probability of 0.002%.

  15. Hunton Group core workshop and field trip

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, K.S. [ed.

    1993-12-31

    The Late Ordovician-Silurian-Devonian Hunton Group is a moderately thick sequence of shallow-marine carbonates deposited on the south edge of the North American craton. This rock unit is a major target for petroleum exploration and reservoir development in the southern Midcontinent. The workshop described here was held to display cores, outcrop samples, and other reservoir-characterization studies of the Hunton Group and equivalent strata throughout the region. A field trip was organized to complement the workshop by allowing examination of excellent outcrops of the Hunton Group of the Arbuckle Mountains.

  16. Improved recovery from Gulf of Mexico reservoirs. Quarterly status report, January 1--March 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Kimbrell, W.C.; Bassiouni, Z.A.; Bourgoyne, A.T.

    1996-04-30

    On February 18, 1992, Louisiana State University with two technical subcontractors, BDM, Inc. and ICF, Inc., began a research program to estimate the potential oil and gas reserve additions that could result from the application of advanced secondary and enhanced oil recovery technologies and the exploitation of undeveloped and attic oil zones in the Gulf of Mexico oil fields that are related to piercement salt domes. This project is a one year continuation of this research and will continue work in reservoir description, extraction processes, and technology transfer. Detailed data will be collected for two previously studies reservoirs: a South Marsh Island reservoir operated by Taylor Energy and one additional Gulf of Mexico reservoir operated by Mobil. Additional reservoirs identified during the project will also be studied if possible. Data collected will include reprocessed 2-D seismic data, newly acquired 3-D data, fluid data, fluid samples, pressure data, well test data, well logs, and core data/samples. The new data will be used to refine reservoir and geologic characterization of these reservoirs. Further laboratory investigation will provide additional simulation input data in the form of PVT properties, relative permeabilities, capillary pressure, and water compatibility. Geological investigations will be conducted to refine the models of mud-rich submarine fan architectures used by seismic analysts and reservoir engineers. Research on advanced reservoir simulation will also be conducted. This report describes a review of fine-grained submarine fans and turbidite systems.

  17. INVESTIGATION OF EFFICIENCY IMPROVEMENTS DURING CO2 INJECTION IN HYDRAULICALLY AND NATURALLY FRACTURED RESERVOIRS

    Energy Technology Data Exchange (ETDEWEB)

    David S. Schechter

    2005-04-27

    This report describes the work performed during the fourth year of the project, ''Investigating of Efficiency Improvements during CO{sub 2} Injection in Hydraulically and Naturally Fractured Reservoirs.'' The objective of this project is to perform unique laboratory experiments with artificially fractured cores (AFCs) and X-ray CT scanner to examine the physical mechanisms of bypassing in hydraulically fractured reservoirs (HFR) and naturally fractured reservoirs (NFR) that eventually result in more efficient CO{sub 2} flooding in heterogeneous or fracture-dominated reservoirs. In Chapter 1, we worked with DOE-RMOTC to investigate fracture properties in the Tensleep Formation at Teapot Dome Naval Reserve as part of their CO{sub 2} sequestration project. In Chapter 2, we continue our investigation to determine the primary oil recovery mechanism in a short vertically fractured core. Finally in Chapter 3, we report our numerical modeling efforts to develop compositional simulator with irregular grid blocks.

  18. INNOVATIVE MIOR PROCESS UTILIZING INDIGENOUS RESERVOIR CONSTITUENTS

    Energy Technology Data Exchange (ETDEWEB)

    D.O. Hitzman; A.K. Stepp; D.M. Dennis; L.R. Graumann

    2003-09-01

    This research program was directed at improving the knowledge of reservoir ecology and developing practical microbial solutions and technologies for improving oil production. The goal was to identify and utilize indigenous microbial populations which can produce beneficial metabolic products and develop a methodology to stimulate those select microbes with nutrient amendments to increase oil recovery. This microbial technology has the capability of producing multiple oil-releasing agents. Experimental laboratory work in model sandpack cores was conducted using microbial cultures isolated from produced water samples. Comparative laboratory studies demonstrating in situ production of microbial products as oil recovery agents were conducted in sand packs with natural field waters using cultures and conditions representative of oil reservoirs. Increased oil recovery in multiple model sandpack systems was achieved and the technology and results were verified by successful field studies. Direct application of the research results has lead to the development of a feasible, practical, successful, and cost-effective technology which increases oil recovery. This technology is now being commercialized and applied in numerous field projects to increase oil recovery. Two field applications of the developed technology reported production increases of 21% and 24% in oil recovery.

  19. INNOVATIVE MIOR PROCESS UTILIZING INDIGENOUS RESERVOIR CONSTITUENTS

    Energy Technology Data Exchange (ETDEWEB)

    D.O. Hitzman; S.A. Bailey

    2000-01-01

    This research program is directed at improving the knowledge of reservoir ecology and developing practical microbial solutions for improving oil production. The goal is to identify indigenous microbial populations which can produce beneficial metabolic products and develop a methodology to stimulate those select microbes with inorganic nutrient amendments to increase oil recovery.This microbial technology has the capability of producing multiple oil releasing agents. The potential of the system will be illustrated and demonstrated by the example of biopolymer production on oil recovery. Research has begun on the program and experimental laboratory work is underway. Polymer-producing cultures have been isolated from produced water samples and initially characterized. Concurrently, a microcosm scale sand-packed column has been designed and developed for testing cultures of interest, including polymer-producing strains. In research that is planned to begin in future work, comparative laboratory studies demonstrating in situ production of microbial products as oil recovery agents will be conducted in sand pack and cores with synthetic and natural field waters at concentrations, flooding rates, and with cultures and conditions representative of oil reservoirs.

  20. Study on fracture identification of shale reservoir based on electrical imaging logging

    Science.gov (United States)

    Yu, Zhou; Lai, Fuqiang; Xu, Lei; Liu, Lin; Yu, Tong; Chen, Junyu; Zhu, Yuantong

    2017-05-01

    In recent years, shale gas exploration has made important development, access to a major breakthrough, in which the study of mud shale fractures is extremely important. The development of fractures has an important role in the development of gas reservoirs. Based on the core observation and the analysis of laboratory flakes and laboratory materials, this paper divides the lithology of the shale reservoirs of the XX well in Zhanhua Depression. Based on the response of the mudstone fractures in the logging curve, the fracture development and logging Response to the relationship between the conventional logging and electrical imaging logging to identify the fractures in the work, the final completion of the type of fractures in the area to determine and quantify the calculation of fractures. It is concluded that the fracture type of the study area is high and the microstructures are developed from the analysis of the XX wells in Zhanhua Depression. The shape of the fractures can be clearly seen by imaging logging technology to determine its type.

  1. Using Biosurfactants Produced from Agriculture Process Waste Streams to Improve Oil Recovery in Fractured Carbonate Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Stephen Johnson; Mehdi Salehi; Karl Eisert; Sandra Fox

    2009-01-07

    This report describes the progress of our research during the first 30 months (10/01/2004 to 03/31/2007) of the original three-year project cycle. The project was terminated early due to DOE budget cuts. This was a joint project between the Tertiary Oil Recovery Project (TORP) at the University of Kansas and the Idaho National Laboratory (INL). The objective was to evaluate the use of low-cost biosurfactants produced from agriculture process waste streams to improve oil recovery in fractured carbonate reservoirs through wettability mediation. Biosurfactant for this project was produced using Bacillus subtilis 21332 and purified potato starch as the growth medium. The INL team produced the biosurfactant and characterized it as surfactin. INL supplied surfactin as required for the tests at KU as well as providing other microbiological services. Interfacial tension (IFT) between Soltrol 130 and both potential benchmark chemical surfactants and crude surfactin was measured over a range of concentrations. The performance of the crude surfactin preparation in reducing IFT was greater than any of the synthetic compounds throughout the concentration range studied but at low concentrations, sodium laureth sulfate (SLS) was closest to the surfactin, and was used as the benchmark in subsequent studies. Core characterization was carried out using both traditional flooding techniques to find porosity and permeability; and NMR/MRI to image cores and identify pore architecture and degree of heterogeneity. A cleaning regime was identified and developed to remove organic materials from cores and crushed carbonate rock. This allowed cores to be fully characterized and returned to a reproducible wettability state when coupled with a crude-oil aging regime. Rapid wettability assessments for crushed matrix material were developed, and used to inform slower Amott wettability tests. Initial static absorption experiments exposed limitations in the use of HPLC and TOC to determine

  2. Forest structure of artificial islands in the Tucuruí dam reservoir in northern Brazil: a test core-area model Estrutura da floresta em ilhas artificiais no reservatório da usina hidrelétrica de Tucuruí, Brasil: um teste do modelo de área nuclear

    Directory of Open Access Journals (Sweden)

    Leandro V. Ferreira

    2012-06-01

    Full Text Available Construction of hydroelectric dams in tropical regions has been contributing significantly to forest fragmentation. Alterations at edges of forest fragments impact plant communities that suffer increases in tree damage and dead, and decreases in seedling recruitment. This study aimed to test the core-area model in a fragmented landscape caused by construction of a hydroelectric power plant in the Brazilian Amazon. We studied variations in forest structure between the margin and interiors of 17 islands of 8-100 hectares in the Tucuruí dam reservoir, in two plots (30 and >100m from the margin per island. Mean tree density, basal area, seedling density and forest cover did not significantly differ between marginal and interior island plots. Also, no significant differences were found in liana density, dead tree or damage for margin and interior plots. The peculiar topographic conditions associated with the matrix habitat and shapes of the island seem to extend edge effects to the islands' centers independently of the island size, giving the interior similar physical microclimatic conditions as at the edges. We propose a protocol for assessing the ecological impacts of edge effects in fragments of natural habitat surrounded by induced (artificial edges. The protocol involves three steps: (1 identification of focal taxa of particular conservation or management interest, (2 measurement of an "edge function" that describes the response of these taxa to induced edges, and (3 use of a "Core-Area Model" to extrapolate edge function parameters to existing or novel situations.A construção de usinas hidrelétricas em regiões tropicais tem contribuído significativamente para a fragmentação da floresta. As alterações nas bordas de fragmentos florestais causam profundos impactos na comunidade de plantas, tais como, o aumento em de árvores mortas ou danificadas e a diminuição do recrutamento de plântulas. Este estudo tem como objetivo testar o

  3. AGR core safety assessment methodologies

    International Nuclear Information System (INIS)

    McLachlan, N.; Reed, J.; Metcalfe, M.P.

    1996-01-01

    To demonstrate the safety of its gas-cooled graphite-moderated AGR reactors, nuclear safety assessments of the cores are based upon a methodology which demonstrates no component failures, geometrical stability of the structure and material properties bounded by a database. All AGRs continue to meet these three criteria. However, predictions of future core behaviour indicate that the safety case methodology will eventually need to be modified to deal with new phenomena. A new approach to the safety assessment of the cores is currently under development, which can take account of these factors while at the same time providing the same level of protection for the cores. This approach will be based on the functionality of the core: unhindered movement of control rods, continued adequate cooling of the fuel and the core, continued ability to charge and discharge fuel. (author). 5 figs

  4. Understanding the True Stimulated Reservoir Volume in Shale Reservoirs

    KAUST Repository

    Hussain, Maaruf

    2017-06-06

    Successful exploitation of shale reservoirs largely depends on the effectiveness of hydraulic fracturing stimulation program. Favorable results have been attributed to intersection and reactivation of pre-existing fractures by hydraulically-induced fractures that connect the wellbore to a larger fracture surface area within the reservoir rock volume. Thus, accurate estimation of the stimulated reservoir volume (SRV) becomes critical for the reservoir performance simulation and production analysis. Micro-seismic events (MS) have been commonly used as a proxy to map out the SRV geometry, which could be erroneous because not all MS events are related to hydraulic fracture propagation. The case studies discussed here utilized a fully 3-D simulation approach to estimate the SRV. The simulation approach presented in this paper takes into account the real-time changes in the reservoir\\'s geomechanics as a function of fluid pressures. It is consisted of four separate coupled modules: geomechanics, hydrodynamics, a geomechanical joint model for interfacial resolution, and an adaptive re-meshing. Reservoir stress condition, rock mechanical properties, and injected fluid pressure dictate how fracture elements could open or slide. Critical stress intensity factor was used as a fracture criterion governing the generation of new fractures or propagation of existing fractures and their directions. Our simulations were run on a Cray XC-40 HPC system. The studies outcomes proved the approach of using MS data as a proxy for SRV to be significantly flawed. Many of the observed stimulated natural fractures are stress related and very few that are closer to the injection field are connected. The situation is worsened in a highly laminated shale reservoir as the hydraulic fracture propagation is significantly hampered. High contrast in the in-situ stresses related strike-slip developed thereby shortens the extent of SRV. However, far field nature fractures that were not connected to

  5. Core calculations of JMTR

    Energy Technology Data Exchange (ETDEWEB)

    Nagao, Yoshiharu [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

    1998-03-01

    In material testing reactors like the JMTR (Japan Material Testing Reactor) of 50 MW in Japan Atomic Energy Research Institute, the neutron flux and neutron energy spectra of irradiated samples show complex distributions. It is necessary to assess the neutron flux and neutron energy spectra of an irradiation field by carrying out the nuclear calculation of the core for every operation cycle. In order to advance core calculation, in the JMTR, the application of MCNP to the assessment of core reactivity and neutron flux and spectra has been investigated. In this study, in order to reduce the time for calculation and variance, the comparison of the results of the calculations by the use of K code and fixed source and the use of Weight Window were investigated. As to the calculation method, the modeling of the total JMTR core, the conditions for calculation and the adopted variance reduction technique are explained. The results of calculation are shown. Significant difference was not observed in the results of neutron flux calculations according to the difference of the modeling of fuel region in the calculations by K code and fixed source. The method of assessing the results of neutron flux calculation is described. (K.I.)

  6. Magnetic nanocomposites with drug-intercalated layered double hydroxide shell supported on commercial magnetite and laboratory-made magnesium ferrite core materials

    Energy Technology Data Exchange (ETDEWEB)

    Ay, Ahmet Nedim, E-mail: ay@hacettepe.edu.tr; Konuk, Deniz; Zuemreoglu-Karan, Birguel

    2011-07-20

    Mg-Al-layered double hydroxide intercalated with a model drug, salicylate, was deposited on laboratory-made magnesium ferrite and commercial magnetite nanoparticles. The obtained core-shell nanocomposites have been characterized by a variety of methods. The combined information from X-ray diffraction patterns, electron diffraction patterns, FTIR spectra, X-ray photoelectron spectra, electron microscopy images, thermogravimetric analysis and microchemical analysis has indicated a similar nature and composition for the two samples. Magnetic measurements have revealed that although the inherent magnetization of magnetite was significantly higher, the nanocomposites displayed nearly similar magnetic properties.

  7. Multiscale Fractal Characterization of Hierarchical Heterogeneity in Sandstone Reservoirs

    Science.gov (United States)

    Liu, Yanfeng; Liu, Yuetian; Sun, Lu; Liu, Jian

    2016-07-01

    Heterogeneities affecting reservoirs often develop at different scales. Previous studies have described these heterogeneities using different parameters depending on their size, and there is no one comprehensive method of reservoir evaluation that considers every scale. This paper introduces a multiscale fractal approach to quantify consistently the hierarchical heterogeneities of sandstone reservoirs. Materials taken from typical depositional pattern and aerial photography are used to represent three main types of sandstone reservoir: turbidite, braided, and meandering river system. Subsequent multiscale fractal dimension analysis using the Bouligand-Minkowski method characterizes well the hierarchical heterogeneity of the sandstone reservoirs. The multiscale fractal dimension provides a curve function that describes the heterogeneity at different scales. The heterogeneity of a reservoir’s internal structure decreases as the observational scale increases. The shape of a deposit’s facies is vital for quantitative determination of the sedimentation type, and thus enhanced oil recovery. Characterization of hierarchical heterogeneity by multiscale fractal dimension can assist reservoir evaluation, geological modeling, and even the design of well patterns.

  8. The Worldwide Marine Radiocarbon Reservoir Effect: Definitions, Mechanisms, and Prospects

    Science.gov (United States)

    Alves, Eduardo Q.; Macario, Kita; Ascough, Philippa; Bronk Ramsey, Christopher

    2018-03-01

    When a carbon reservoir has a lower radiocarbon content than the atmosphere, this is referred to as a reservoir effect. This is expressed as an offset between the radiocarbon ages of samples from the two reservoirs at a single point in time. The marine reservoir effect (MRE) has been a major concern in the radiocarbon community, as it introduces an additional source of error that is often difficult to accurately quantify. For this reason, researchers are often reluctant to date marine material where they have another option. The influence of this phenomenon makes the study of the MRE important for a broad range of applications. The advent of Accelerator Mass Spectrometry (AMS) has reduced sample size requirements and increased measurement precision, in turn increasing the number of studies seeking to measure marine samples. These studies rely on overcoming the influence of the MRE on marine radiocarbon dates through the worldwide quantification of the local parameter ΔR, that is, the local variation from the global average MRE. Furthermore, the strong dependence on ocean dynamics makes the MRE a useful indicator for changes in oceanic circulation, carbon exchange between reservoirs, and the fate of atmospheric CO2, all of which impact Earth's climate. This article explores data from the Marine Reservoir Database and reviews the place of natural radiocarbon in oceanic records, focusing on key questions (e.g., changes in ocean dynamics) that have been answered by MRE studies and on their application to different subjects.

  9. The stable Cr isotopic compositions of chondrites and silicate planetary reservoirs

    Science.gov (United States)

    Schoenberg, Ronny; Merdian, Alexandra; Holmden, Chris; Kleinhanns, Ilka C.; Haßler, Kathrin; Wille, Martin; Reitter, Elmar

    2016-06-01

    The depletion of chromium in Earth's mantle (∼2700 ppm) in comparison to chondrites (∼4400 ppm) indicates significant incorporation of chromium into the core during our planet's metal-silicate differentiation, assuming that there was no significant escape of the moderately volatile element chromium during the accretionary phase of Earth. Stable Cr isotope compositions - expressed as the ‰-difference in 53Cr/52Cr from the terrestrial reference material SRM979 (δ53/52CrSRM979 values) - of planetary silicate reservoirs might thus yield information about the conditions of planetary metal segregation processes when compared to chondrites. The stable Cr isotopic compositions of 7 carbonaceous chondrites, 11 ordinary chondrites, 5 HED achondrites and 2 martian meteorites determined by a double spike MC-ICP-MS method are within uncertainties indistinguishable from each other and from the previously determined δ53/52CrSRM979 value of -0.124 ± 0.101‰ for the igneous silicate Earth. Extensive quality tests support the accuracy of the stable Cr isotope determinations of various meteorites and terrestrial silicates reported here. The uniformity in stable Cr isotope compositions of samples from planetary silicate mantles and undifferentiated meteorites indicates that metal-silicate differentiation of Earth, Mars and the HED parent body did not cause measurable stable Cr isotope fractionation between these two reservoirs. Our results also imply that the accretionary disc, at least in the inner solar system, was homogeneous in its stable Cr isotopic composition and that potential volatility loss of chromium during accretion of the terrestrial planets was not accompanied by measurable stable isotopic fractionation. Small but reproducible variations in δ53/52CrSRM979 values of terrestrial magmatic rocks point to natural stable Cr isotope variations within Earth's silicate reservoirs. Further and more detailed studies are required to investigate whether silicate

  10. Chickamauga reservoir embayment study - 1990

    Energy Technology Data Exchange (ETDEWEB)

    Meinert, D.L.; Butkus, S.R.; McDonough, T.A.

    1992-12-01

    The objectives of this report are three-fold: (1) assess physical, chemical, and biological conditions in the major embayments of Chickamauga Reservoir; (2) compare water quality and biological conditions of embayments with main river locations; and (3) identify any water quality concerns in the study embayments that may warrant further investigation and/or management actions. Embayments are important areas of reservoirs to be considered when assessments are made to support water quality management plans. In general, embayments, because of their smaller size (water surface areas usually less than 1000 acres), shallower morphometry (average depth usually less than 10 feet), and longer detention times (frequently a month or more), exhibit more extreme responses to pollutant loadings and changes in land use than the main river region of the reservoir. Consequently, embayments are often at greater risk of water quality impairments (e.g. nutrient enrichment, filling and siltation, excessive growths of aquatic plants, algal blooms, low dissolved oxygen concentrations, bacteriological contamination, etc.). Much of the secondary beneficial use of reservoirs occurs in embayments (viz. marinas, recreation areas, parks and beaches, residential development, etc.). Typically embayments comprise less than 20 percent of the surface area of a reservoir, but they often receive 50 percent or more of the water-oriented recreational use of the reservoir. This intensive recreational use creates a potential for adverse use impacts if poor water quality and aquatic conditions exist in an embayment.

  11. Permeability Prediction for Nahr-Umr Reservoir / Subba field by Using FZI Method

    Directory of Open Access Journals (Sweden)

    Sameera M. Hamd- Allah

    2016-09-01

    Full Text Available The permeability determination in the reservoirs that are anisotropic and heterogeneous is a complicated problem due to the limited number of wells that contain core samples and well test data. This paper presents hydraulic flow units and flow zone indicator for predicting permeability of rock mass from core for Nahr-Umr reservoir/ Subba field. The Permeability measurement is better found in the laboratory work on the cored rock that taken from the formation. Nahr-Umr Formation is the main lower cretaceous sandstone reservoir in southern of Iraq. This formation is made up mainly of sandstone. Nahr-Umr formation was deposited on a gradually rising basin floor. The digenesis of Nahr-Umr sediments is very important due to its direct relation to the porosity and permeability. In this study permeability has been predicated by using the flow zone indicator methods. This method attempts to identify the flow zone indicator in un-cored wells using log records. Once the flow zone indicator is calculated from the core data, a relationship between this FZI value and the well logs can be obtained. Three relationships have been found for Nahr-Umr reservoir/Subba field by FZI method. By plotting the permeability of the core versus the permeability that is predicted by FZI method the parameter R2 was found (0.905 which is very good for predict the permeability.

  12. A Novel Method for Performance Analysis of Compartmentalized Reservoirs

    Directory of Open Access Journals (Sweden)

    Shahamat Mohammad Sadeq

    2016-05-01

    Full Text Available This paper presents a simple analytical model for performance analysis of compartmentalized reservoirs producing under Constant Terminal Rate (CTR and Constant Terminal Pressure (CTP. The model is based on the well-known material balance and boundary dominated flow equations and is written in terms of capacitance and resistance of a production and a support compartment. These capacitance and resistance terms account for a combination of reservoir parameters which enable the developed model to be used for characterizing such systems. In addition to considering the properties contrast between the two reservoir compartments, the model takes into account existence of transmissibility barriers with the use of resistance terms. The model is used to analyze production performance of unconventional reservoirs, where the multistage fracturing of horizontal wells effectively creates a Stimulated Reservoir Volume (SRV with an enhanced permeability surrounded by a non-stimulated region. It can also be used for analysis of compartmentalized conventional reservoirs. The analytical solutions provide type curves through which the controlling reservoirs parameters of a compartmentalized system can be estimated. The contribution of the supporting compartment is modeled based on a boundary dominated flow assumption. The transient behaviour of the support compartment is captured by application of “distance of investigation” concept. The model shows that depletion of the production and support compartments exhibit two unit slopes on a log-log plot of pressure versus time for CTR. For CTP, however, the depletions display two exponential declines. The depletion signatures are separated by transition periods, which depend on the contribution of the support compartment (i.e. transient or boundary dominated flow. The developed equations can be implemented easily in a spreadsheet application, and are corroborated with the use of a numerical simulation. The study

  13. Extracting maximum petrophysical and geological information from a limited reservoir database

    Energy Technology Data Exchange (ETDEWEB)

    Ali, M.; Chawathe, A.; Ouenes, A. [New Mexico Institute of Mining and Technology, Socorro, NM (United States)] [and others

    1997-08-01

    The characterization of old fields lacking sufficient core and log data is a challenging task. This paper describes a methodology that uses new and conventional tools to build a reliable reservoir model for the Sulimar Queen field. At the fine scale, permeability measured on a fine grid with a minipermeameter was used in conjunction with the petrographic data collected on multiple thin sections. The use of regression analysis and a newly developed fuzzy logic algorithm led to the identification of key petrographic elements which control permeability. At the log scale, old gamma ray logs were first rescaled/calibrated throughout the entire field for consistency and reliability using only four modem logs. Using data from one cored well and the rescaled gamma ray logs, correlations between core porosity, permeability, total water content and gamma ray were developed to complete the small scale characterization. At the reservoir scale, outcrop data and the rescaled gamma logs were used to define the reservoir structure over an area of ten square miles where only 36 wells were available. Given the structure, the rescaled gamma ray logs were used to build the reservoir volume by identifying the flow units and their continuity. Finally, history-matching results constrained to the primary production were used to estimate the dynamic reservoir properties such as relative permeabilities to complete the characterization. The obtained reservoir model was tested by forecasting the waterflood performance and which was in good agreement with the actual performance.

  14. Petroleum reservoir data for testing simulation models

    Energy Technology Data Exchange (ETDEWEB)

    Lloyd, J.M.; Harrison, W.

    1980-09-01

    This report consists of reservoir pressure and production data for 25 petroleum reservoirs. Included are 5 data sets for single-phase (liquid) reservoirs, 1 data set for a single-phase (liquid) reservoir with pressure maintenance, 13 data sets for two-phase (liquid/gas) reservoirs and 6 for two-phase reservoirs with pressure maintenance. Also given are ancillary data for each reservoir that could be of value in the development and validation of simulation models. A bibliography is included that lists the publications from which the data were obtained.

  15. Utilizing a Spiro Core with Acridine- and Phenothiazine-Based New Hole Transporting Materials for Highly Efficient Green Phosphorescent Organic Light-Emitting Diodes.

    Science.gov (United States)

    Braveenth, Ramanaskanda; Bae, Il-Ji; Han, Ji-Hun; Qiong, Wu; Seon, Guk; Raagulan, Kanthasamy; Yang, Kihun; Park, Young Hee; Kim, Miyoung; Chai, Kyu Yun

    2018-03-21

    Two new hole transporting materials, 2,7-bis(9,9-diphenylacridin-10(9 H )-yl)-9,9' spirobi[fluorene] (SP1) and 2,7-di(10 H -phenothiazin-10-yl)-9,9'-spirobi[fluorene] (SP2), were designed and synthesized by using the Buchwald-Hartwig coupling reaction with a high yield percentage of over 84%. Both of the materials exhibited high glass transition temperatures of over 150 °C. In order to understand the device performances, we have fabricated green phosphorescent organic light-emitting diodes (PhOLEDs) with SP1 and SP2 as hole transporting materials. Both of the materials revealed improved device properties, in particular, the SP2-based device showed excellent power (34.47 lm/W) and current (38.41 cd/A) efficiencies when compare with the 4,4'-bis( N -phenyl-1-naphthylamino)biphenyl (NPB)-based reference device (30.33 lm/W and 32.83 cd/A). The external quantum efficiency (EQE) of SP2 was 13.43%, which was higher than SP1 (13.27%) and the reference material (11.45%) with a similar device structure. The SP2 hole transporting material provides an effective charge transporting path from anode to emission layer, which is explained by the device efficiencies.

  16. Utilizing a Spiro Core with Acridine- and Phenothiazine-Based New Hole Transporting Materials for Highly Efficient Green Phosphorescent Organic Light-Emitting Diodes

    Directory of Open Access Journals (Sweden)

    Ramanaskanda Braveenth

    2018-03-01

    Full Text Available Two new hole transporting materials, 2,7-bis(9,9-diphenylacridin-10(9H-yl-9,9′ spirobi[fluorene] (SP1 and 2,7-di(10H-phenothiazin-10-yl-9,9′-spirobi[fluorene] (SP2, were designed and synthesized by using the Buchwald–Hartwig coupling reaction with a high yield percentage of over 84%. Both of the materials exhibited high glass transition temperatures of over 150 °C. In order to understand the device performances, we have fabricated green phosphorescent organic light-emitting diodes (PhOLEDs with SP1 and SP2 as hole transporting materials. Both of the materials revealed improved device properties, in particular, the SP2-based device showed excellent power (34.47 lm/W and current (38.41 cd/A efficiencies when compare with the 4,4′-bis(N-phenyl-1-naphthylaminobiphenyl (NPB-based reference device (30.33 lm/W and 32.83 cd/A. The external quantum efficiency (EQE of SP2 was 13.43%, which was higher than SP1 (13.27% and the reference material (11.45% with a similar device structure. The SP2 hole transporting material provides an effective charge transporting path from anode to emission layer, which is explained by the device efficiencies.

  17. Nano-scale experimental investigation of in-situ wettability and spontaneous imbibition in ultra-tight reservoir rocks

    Science.gov (United States)

    Akbarabadi, Morteza; Saraji, Soheil; Piri, Mohammad; Georgi, Dan; Delshad, Mohammad

    2017-09-01

    We investigated spontaneous imbibition behavior, three-dimensional fluid occupancy maps, and in-situ wettability at the nano scale in five ultra-tight and shale reservoir rock samples. For this purpose, we developed a novel technique by integrating a custom-built in-situ miniature fluid-injection module with a non-destructive high-resolution X-ray imaging system. Small cylindrical core samples (15-60 μm in diameter) were prepared from reservoir rocks using Focused-Ion Beam (FIB) milling technique. The pore network inside the samples were first characterized using ultra-high resolution three-dimensional images obtained at initial state by X-ray nano-tomography (Nano-CT) and FIB-Scanning Electron Microscopy (FIB-SEM) techniques at the nano scale. The petrophysical parameters, including porosity, permeability, pore-size distribution, and organic content were computed for each sample using image analysis. We then performed series of imbibition experiments using brine, oil, and surfactant solutions on each core sample. We observed that both oil and brine phases spontaneously imbibe into the pore network of the rock samples at various quantities. We also, for the first time, examined fluid distribution in individual pores and found a complex wettability behavior at the pore scale in the reservoir rock samples. Three pore types were identified with water-wet, oil-wet, and fractionally-wet behaviors. This work opens a new path to developing an improved understanding of the pore-level physics involved in multi-phase flow and transport not only in tight rock samples but also in other nanoporous material used in different science and engineering applications.

  18. Core-to-core dimers forming switchable mesophase

    Czech Academy of Sciences Publication Activity Database

    Horčic, M.; Svoboda, J.; Novotná, Vladimíra; Pociecha, D.; Gorecka, E.

    2017-01-01

    Roč. 53, č. 18 (2017), s. 2721-2724 ISSN 1359-7345 R&D Projects: GA ČR GA15-02843S Institutional support: RVO:68378271 Keywords : liquid crystals * bent-core mesogens * dimers Subject RIV: JJ - Other Materials OBOR OECD: Nano-materials (production and properties) Impact factor: 6.319, year: 2016

  19. Biofouling on Reservoir in Sea Water

    Science.gov (United States)

    Yoon, H.; Eom, C.; Kong, M.; Park, Y.; Chung, K.; Kim, B.

    2011-12-01

    The organisms which take part in marine biofouling are primarily the attached or sessile forms occurring naturally in the shallower water along the coast [1]. This is mainly because only those organisms with the ability to adapt to the new situations created by man can adhere firmly enough to avoid being washed off. Chemical and microbiological characteristics of the fouling biofilms developed on various surfaces in contact with the seawater were made. The microbial compositions of the biofilm communities formed on the reservoir polymer surfaces were tested for. The quantities of the diverse microorganisms in the biofilm samples developed on the prohibiting polymer reservoir surface were larger when there was no concern about materials for special selection for fouling. To confirm microbial and formation of biofilm on adsorbents was done CLSM (Multi-photon Confocal Laser Scanning Microscope system) analysis. Microbial identified using 16S rRNA. Experiment results, five species which are Vibrio sp., Pseudoalteromonas, Marinomonas, Sulfitobacter, and Alteromonas discovered to reservoir formed biofouling. There are some microorganism cause fouling and there are the others control fouling. The experimental results offered new specific information, concerning the problems in the application of new material as well as surface coating such as anti-fouling coatings. They showed the important role microbial activity in fouling and corrosion of the surfaces in contact with the any seawater. Acknowledgement : This research was supported by the national research project titled "The Development of Technology for Extraction of Resources Dissolved in Seawater" of the Korea Institute of Geoscience and Mineral Resources (KIGAM) funded by the Ministry of Land, Transport and Maritime Affairs. References [1] M. Y. Diego, K. Soren, and D. J. Kim. Prog. Org. Coat. 50, (2004) p.75-104.

  20. Gravity observations for hydrocarbon reservoir monitoring

    OpenAIRE

    Glegola, M.A.

    2013-01-01

    In this thesis the added value of gravity observations for hydrocarbon reservoir monitoring and characterization is investigated. Reservoir processes and reservoir types most suitable for gravimetric monitoring are identified. Major noise sources affecting time-lapse gravimetry are analyzed. The added value of gravity data for reservoir monitoring and characterization is analyzed within closed-loop reservoir management concept. Synthetic 2D and 3D numerical experiments are performed where var...

  1. Sedimentation rate and {sup 210}Pb sediment dating at Apipucos reservoir, Recife, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Figueiredo, Marcela D.C. de; Silva, Danubia B. da; Cunha, Manuela S. da; Rodrigues, Kelia R.G.; Pedroza, Eryka H.; Melo, Roberto T. de; Oliveira, Aristides; Hazin, Clovis A.; Souza, Vivianne L.B. de, E-mail: rtmelo@cnen.gov.b, E-mail: chazin@cnen.gov.b, E-mail: vlsouza@cnen.gov.b [Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2011-07-01

    The Apipucos Reservoir is located in Recife, State of Pernambuco, and, several districts of the metropolitan area use this reservoir to dispose waste and sewage. Dating sediments uses {sup 210}Pb from the atmosphere which is formed as a result of {sup 222}Rn emanation from the soil. Atmospheric lead, carried by rain, is called non-supported {sup 21}'0Pb, to differentiate it from the one contained in the sediment, in balance with the {sup 226}Ra. The model chosen for dating sediments depends on certain conditions: in an environment where the amount of sediment influx can vary, the constant rate of supply model is adopted. On the other hand, in environments where the sedimentation rate is constant and the sediment can be considered to have a constant initial concentration of unsupported {sup 210}Pb and the (CIC) model is applied. A 70-cm long, 5-cm internal-diameter wide core was collected for sediment dating. Each core was sliced, into 5 or 10 cm intervals. Samples were dried at 105 deg C, and about 5 g dry material from each sample was dissolved with acids. The {sup 210}Pb and {sup 226}Ra contents were separated and determined by beta and alpha counting by using a gas-flow proportional counter. Sediment ages were calculated by the two models, and for the second and fourth sampling points, both models could be used. The results showed an increase in sedimentation rate over the last 50 - 60 years. We can conclude that the top sediment layer is dated from 30 years ago. We can also conclude that the CRS is the best applicable model to use in this area. (author)

  2. Reservoir rock permeability prediction using support vector regression in an Iranian oil field

    International Nuclear Information System (INIS)

    Saffarzadeh, Sadegh; Shadizadeh, Seyed Reza

    2012-01-01

    Reservoir permeability is a critical parameter for the evaluation of hydrocarbon reservoirs. It is often measured in the laboratory from reservoir core samples or evaluated from well test data. The prediction of reservoir rock permeability utilizing well log data is important because the core analysis and well test data are usually only available from a few wells in a field and have high coring and laboratory analysis costs. Since most wells are logged, the common practice is to estimate permeability from logs using correlation equations developed from limited core data; however, these correlation formulae are not universally applicable. Recently, support vector machines (SVMs) have been proposed as a new intelligence technique for both regression and classification tasks. The theory has a strong mathematical foundation for dependence estimation and predictive learning from finite data sets. The ultimate test for any technique that bears the claim of permeability prediction from well log data is the accurate and verifiable prediction of permeability for wells where only the well log data are available. The main goal of this paper is to develop the SVM method to obtain reservoir rock permeability based on well log data. (paper)

  3. Identification of Environment Chase in Surround of Sermo Reservoir; and the Influence Possibility for Function and at the Age of Reservoi

    Directory of Open Access Journals (Sweden)

    Sudarmadji Sudarmadji

    2004-01-01

    materials from land slide occuring around the reservoir; due to distruction of land in constructing the relatively new ring-road close to the shore line of the reservoir: Of course, the sediment is also coming from rivers entering die reservoir. Sermo reservoir is a relatively young reservoir; the early observation of environmental changes of the reservoir could hopely be used as indicator to study ecological changes of the area within and around of the reservoir; and could be used as a comparison to other reservoirs, as well as basic environmental management of the reservoir and its surrounding.

  4. 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.

  5. A scalable route to prepare core-shell structured ZnO@PEDOT nanowires and PEDOT nanotubes and their properties as electrode materials

    Science.gov (United States)

    Wang, Fang; Zhang, Xianhong; Yang, Le; Xu, Dehong; Ma, Yuhong; Chen, Dong; Wang, Li; Zhao, Changwen; Yang, Wantai

    2016-05-01

    A composite of a core-shell structured nanowires with ZnO as a core and conductive poly(3,4-ethylenedioxythiophene) (PEDOT) as a shell was prepared. At first, the hexagonal ZnO nanowires, with diameter of about 80-100 nm and length 4-5 μm, were fabricated by hydrothermal synthesis process. Then a thick layer of poly(trifluoroethyl methacrylate)-block-poly(sodium styrene sulfonate) (PTFEMA-b-PSSNa) was grafted from the surface of ZnO nanowires via atom transfer free radical polymerization. At last, with the ZnO@PTFEMA-b-PSSNa as a template and the PSSNa chain as the counterion dopant, PEDOT was precipitated onto the surface of the template to form the composite of ZnO@PEDOT/PSSNa. With the evaluation of the EDOT polymerization, the thickness of the PEDOT layer increased steadily. However, as the ratio of EDOT/ZnO was greater than 1:2, the ZnO nanowires templates were dissolved at last and then PEDOT particles were produced due to increasing of the acidity during the oxidation polymerization of EDOT. In this case, the product was the mixture of the nanotubes and particles of PEDOT/PPSNa. The electrochemical capacitances of the composites with different structures were investigated with cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy techniques with three-electrode cell configuration. The maximum specific capacitance of ZnO@PEDOT electrode can reach 101.34 F/g at 20 mV/s.

  6. Analytical Results for 35 Mine-Waste Tailings Cores and Six Bed-Sediment Samples, and An Estimate of the Volume of Contaminated Material at Buckeye Meadow on Upper Basin Creek, Northern Jefferson County, Montana

    Science.gov (United States)

    Fey, David L.; Church, Stan E.; Finney, Christopher J.

    1999-01-01

    Metal-mining related wastes in the Boulder River basin study area in northern Jefferson County, Montana have been implicated in their detrimental effects on water quality with regard to acid-generation and toxic-metal solubilization. Flotation-mill tailings in the meadow below the Buckeye mine, hereafter referred to as the Buckeye mill-tailings site, have been identified as significant contributors to water quality degradation of Basin Creek, Montana. Basin Creek is one of three tributaries to the Boulder River in the study area; bed sediments and waters draining from the Buckeye mine have also been implicated. Geochemical analysis of 35 tailings cores and six bed-sediment samples was undertaken to determine the concentrations of Ag, As, Cd, Cu, Pb,and Zn present in these materials. These elements are environmentally significant, in that they can be toxic to fish and/or the invertebrate organisms that constitute their food. A suite of one-inch cores of dispersed flotation-mill tailings and underlying premining material was taken from a large, flat area north of Basin Creek near the site of the Buckeye mine. Thirty-five core samples were taken and divided into 204 subsamples. The samples were analyzed by ICP-AES (inductively coupled plasma-atomic emission spectroscopy) using a mixed-acid digestion. Results of the core analyses show that the elements listed above are present at moderate to very high concentrations (arsenic to 63,000 ppm, silver to 290 ppm, cadmium to 370 ppm, copper to 4,800 ppm, lead to 93,000 ppm, and zinc to 23,000 ppm). Volume calculations indicate that an estimated 8,400 metric tons of contaminated material are present at the site. Six bed-sediment samples were also subjected to the mixed-acid total digestion, and a warm (50°C) 2M HCl-1% H2O2 leach and analyzed by ICP-AES. Results indicate that bed sediments of Basin Creek are only slightly impacted by past mining above the Buckeye-Enterprise complex, moderately impacted at the upper (eastern

  7. Casting core for a cooling arrangement for a gas turbine component

    Science.gov (United States)

    Lee, Ching-Pang; Heneveld, Benjamin E

    2015-01-20

    A ceramic casting core, including: a plurality of rows (162, 166, 168) of gaps (164), each gap (164) defining an airfoil shape; interstitial core material (172) that defines and separates adjacent gaps (164) in each row (162, 166, 168); and connecting core material (178) that connects adjacent rows (170, 174, 176) of interstitial core material (172). Ends of interstitial core material (172) in one row (170, 174, 176) align with ends of interstitial core material (172) in an adjacent row (170, 174, 176) to form a plurality of continuous and serpentine shaped structures each including interstitial core material (172) from at least two adjacent rows (170, 174, 176) and connecting core material (178).

  8. Reservoir-induced seismicity at Castanhao reservoir, NE Brazil

    Science.gov (United States)

    Nunes, B.; do Nascimento, A.; Ferreira, J.; Bezerra, F.

    2012-04-01

    Our case study - the Castanhão reservoir - is located in NE Brazil on crystalline rock at the Borborema Province. The Borborema Province is a major Proterozoic-Archean terrain formed as a consequence of convergence and collision of the São Luis-West Africa craton and the São Francisco-Congo-Kasai cratons. This reservoir is a 60 m high earth-filled dam, which can store up to 4.5 billion m3 of water. The construction begun in 1990 and finished in October 2003.The first identified reservoir-induced events occurred in 2003, when the water level was still low. The water reached the spillway for the first time in January 2004 and, after that, an increase in seismicity occured. The present study shows the results of a campaign done in the period from November 19th, 2009 to December 31th, 2010 at the Castanhão reservoir. We deployed six three-component digital seismographic station network around one of the areas of the reservoir. We analyzed a total of 77 events which were recorded in at least four stations. To determine hypocenters and time origin, we used HYPO71 program (Lee & Lahr, 1975) assuming a half-space model with following parameters: VP= 5.95 km/s and VP/VS=1.73. We also performed a relocation of these events using HYPODD (Waldhauser & Ellsworth, 2000) programme. The input data used we used were catalogue data, with all absolute times. The results from the spatio-temporal suggest that different clusters at different areas and depths are triggered at different times due to a mixture of: i - pore pressure increase due to diffusion and ii - increase of pore pressure due to the reservoir load.

  9. MAPPING OF RESERVOIR PROPERTIES AND FACIES THROUGH INTEGRATION OF STATIC AND DYNAMIC DATA

    Energy Technology Data Exchange (ETDEWEB)

    Albert C. Reynolds; Dean S. Oliver; Fengjun Zhang; Yannong Dong; Jan Arild Skjervheim; Ning Liu

    2003-01-01

    Knowledge of the distribution of permeability and porosity in a reservoir is necessary for the prediction of future oil production, estimation of the location of bypassed oil, and optimization of reservoir management. But while the volume of data that can potentially provide information on reservoir architecture and fluid distributions has increased enormously in the past decade, it is not yet possible to make use of all the available data in an integrated fashion. While it is relatively easy to generate plausible reservoir models that honor static data such as core, log, and seismic data, it is far more difficult to generate plausible reservoir models that honor dynamic data such as transient pressures, saturations, and flow rates. As a result, the uncertainty in reservoir properties is higher than it could be and reservoir management can not be optimized. The goal of this project is to develop computationally efficient automatic history matching techniques for generating geologically plausible reservoir models which honor both static and dynamic data. Solution of this problem is necessary for the quantification of uncertainty in future reservoir performance predictions and for the optimization of reservoir management. Facies (defined here as regions of relatively uniform petrophysical properties) are common features of all reservoirs. Because the flow properties of the various facies can vary greatly, knowledge of the location of facies boundaries is of utmost importance for the prediction of reservoir performance and for the optimization of reservoir management. When the boundaries between facies are fairly well known, but flow properties are poorly known, the average properties for all facies can be determined using traditional techniques. Traditional history matching honors dynamic data by adjusting petrophysical properties in large areas, but in the process of adjusting the reservoir model ignores the static data and often results in implausible reservoir

  10. Radionuclides and stable elements in the sediments of the Yesa Reservoir, Central Spanish Pyrenees

    Energy Technology Data Exchange (ETDEWEB)

    Navas, Ana; Gaspar, Leticia; Palazon, Leticia [Estacion Experimental Aula Dei (EEAD- CSIC), Zaragoza (Spain). Dept. of Soil and Water; Valero-Garces, Blas [Instituto Pirenaico de Ecologia (IPE-CSIC), Zaragoza (Spain)

    2011-09-15

    Purpose: The sediments accumulated in the Yesa Reservoir (Central Spanish Pyrenees) have greatly decreased its water storage capacity and are a major threat to the sustainability of water resources in the region. This study examines the contents of radionuclides and stable elements in the reservoir sediments and relates their variations with the sediment composition and local sedimentary dynamics, particularly flood frequency and intensity, which are responsible for changes in the main supply and distribution of radionuclides in the basin. Materials and methods: The sedimentary sequence accumulated in the Yesa Reservoir (471 Hm{sup 3}), which supplies water to ca. 1,000,000 people and for irrigation, was examined in two 4-m long sediment cores (Y1, Y2) and one profile (Y3) retrieved at its central part. In the sediments, radionuclide activities of {sup 238}U, {sup 226}Ra, {sup 232}Th, {sup 40}K, {sup 210}Pb and {sup 137}Cs were measured using a hyperpure Ge coaxial detector. The stable elements Mg, Ca, Sr, Ba, Cr, Cu, Mn, Fe, Al, Zn, Ni, Co, Pb, Li, K and Na were analysed by ICP-OES. Complementary analyses to characterize the sediments included: XRD in the profile, grain size distribution by laser equipment and the contents of organic matter, carbonates and the residual fraction by loss on ignition. Results and discussion: The variation in radionuclide activities is associated with grain size and sediment composition. The activity levels (becquerels per kilogram) ranged between 20 and 43 for{sup 238}U, 14 and 40 for {sup 226}Ra, 7 and 56 for {sup 210}Pb, 19 and 46 for Th{sup 232}, 1 and 48 for {sup 137}Cs and 185 and 610 for {sup 40}K. Enriched activity levels are associated with clayey and silty layers, and depleted levels with sandy layers. The levels of radionuclides and trace elements were significantly lower in the cores than in the profile because of its higher silicate content and the influence of inflow of spring mineral-rich waters. The correlations among

  11. MAPPING OF RESERVOIR PROPERTIES AND FACIES THROUGH INTEGRATION OF STATIC AND DYNAMIC DATA

    Energy Technology Data Exchange (ETDEWEB)

    Albert C. Reynolds; Dean S. Oliver; Yannong Dong; Ning Liu; Guohua Gao; Fengjun Zhang; Ruijian Li

    2004-12-01

    Knowledge of the distribution of permeability and porosity in a reservoir is necessary for the prediction of future oil production, estimation of the location of bypassed oil, and optimization of reservoir management. The volume of data that can potentially provide information on reservoir architecture and fluid distributions has increased enormously in the past decade. The techniques developed in this research will make it easier to use all the available data in an integrated fashion. While it is relatively easy to generate plausible reservoir models that honor static data such as core, log, and seismic data, it is far more difficult to generate plausible reservoir models that honor dynamic data such as transient pressures, saturations, and flow rates. As a result, the uncertainty in reservoir properties is higher than it could be and reservoir management can not be optimized. In this project, we have developed computationally efficient automatic history matching techniques for generating geologically plausible reservoir models which honor both static and dynamic data. Specifically, we have developed methods for adjusting porosity and permeability fields to match both production and time-lapse seismic data and have also developed a procedure to adjust the locations of boundaries between facies to match production data. In all cases, the history matched rock property fields are consistent with a prior model based on static data and geologic information. Our work also indicates that it is possible to adjust relative permeability curves when history matching production data.

  12. Characterization of dynamic change of Fan-delta reservoir properties in water-drive development

    Energy Technology Data Exchange (ETDEWEB)

    Wu Shenghe; Xiong Qihua; Liu Yuhong [Univ. of Petroleum Changping, Beijing (China)

    1997-08-01

    Fan-delta reservoir in Huzhuangji oil field of east China, is a typical highly heterogeneous reservoir. The oil field has been developed by water-drive for 10 years, but the oil recovery is less than 12%, and water cut is over 90%, resulting from high heterogeneity and serious dynamic change of reservoir properties. This paper aims at the study of dynamic change of reservoir properties in water-drive development. Through quantitative imaging analysis and mercury injection analysis of cores from inspection wells, the dynamic change of reservoir pore structure in water-drive development was studied. The results show that the {open_quotes}large pore channels{close_quotes} develop in distributary channel sandstone and become larger in water-drive development, resulting in more serious pore heterogeneity. Through reservoir sensitivity experiments, the rock-fluid reaction in water-drive development is studied. The results show the permeability of some distal bar sandstone and deserted channel sandstone becomes lower due to swelling of I/S clay minerals in pore throats. OD the other hand, the permeability of distributary channel and mouth bar sandstone become larger because the authigenic Koalinites in pore throats are flushed away with the increase of flow rate of injection water. Well-logging analysis of flooded reservoirs are used to study the dynamic change of reservoir properties in various flow units. The distribution of remaining oil is closely related to the types and distribution of flow units.

  13. Cloud computing and Reservoir project

    International Nuclear Information System (INIS)

    Beco, S.; Maraschini, A.; Pacini, F.; Biran, O.

    2009-01-01

    The support for complex services delivery is becoming a key point in current internet technology. Current trends in internet applications are characterized by on demand delivery of ever growing amounts of content. The future internet of services will have to deliver content intensive applications to users with quality of service and security guarantees. This paper describes the Reservoir project and the challenge of a reliable and effective delivery of services as utilities in a commercial scenario. It starts by analyzing the needs of a future infrastructure provider and introducing the key concept of a service oriented architecture that combines virtualisation-aware grid with grid-aware virtualisation, while being driven by business service management. This article will then focus on the benefits and the innovations derived from the Reservoir approach. Eventually, a high level view of Reservoir general architecture is illustrated.

  14. TEOA-mediated formation of hollow core-shell structured CoNi2S4 nanospheres as a high-performance electrode material for supercapacitors

    Science.gov (United States)

    Liang, Jun; Li, Meng; Chai, Yao; Luo, Min; Li, Li

    2017-09-01

    In this study, we report for the first time a cost-effective and general approach for the high-yield synthesis of a hierarchical core-shell and hollow structure of ternary CoNi2S4 in a triethanolamine (TEOA)-assisted hydrothermal system. It is found that a continuous increase in TEOA usages facilitates the formation and transformation of hierarchical CoNi2S4 hollow nanospheres, and the formation mechanism of the unique structure is revealed to be assembly-then-inside-out evacuation and Ostwald ripening mechanism during the sulfidation process. More importantly, when used as faradaic electrode for supercapacitors, the hierarchical hollow CoNi2S4 nanospheres display not only exceptional pseudocapacitve performance with high specific capacitance (2035 Fg-1 at 1 Ag-1) and excellent rate capability (1215 Fg-1 at 20 Ag-1), but also superior cycling stability, with only about 8.7% loss over 3000 cycles at 10 Ag-1. This work can provide some guidance for us in the structural and compositional tuning of mixed binary-metal sulfides toward many desired applications.

  15. Double Core-Shell Si@C@SiO2for Anode Material of Lithium-Ion Batteries with Excellent Cycling Stability.

    Science.gov (United States)

    Yang, Tao; Tian, Xiaodong; Li, Xiao; Wang, Kai; Liu, Zhanjun; Guo, Quangui; Song, Yan

    2017-02-10

    Lithium-ion batteries (LIBs) composed of silicon (Si) anodes suffer from severe capacity decay because of the volume expansion deriving from the formation of Li 15 Si 4 alloy. In this study, we prepared a double core-shell Si@C@SiO 2 nanostructure by the modified Stöber method. In the process of Si lithiation, the carbon layer alleviates the large pressure slightly then the silica shell restricts the lithiation degree of Si. The combination of carbon interlayer and silica shell guarantees structural integrity and avoids further decay of capacity because of the formation of stable solid-electrolyte interphase (SEI) films. The resultant Si@C@SiO 2 presents remarkable cycling stability with capacity decay of averagely 0.03 % per cycle over 305 cycles at 200 mA g -1 , an improvement on Si@C (0.22 %) by more than a factor of 7. This encouraging result demonstrates that the designation involved in this work is effective for mitigating the capacity decay of Si-based anodes for LIBs. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. IMPROVING CO2 EFFICIENCY FOR RECOVERING OIL IN HETEROGENEOUS RESERVOIRS

    Energy Technology Data Exchange (ETDEWEB)

    Reid B. Grigg

    2003-10-31

    brine in limestone core. Metal tracers in the brine were used as markers to identify precipitation location and extent. This indicated possible causes of permanent permeability changes in the core and thus in a reservoir. Core segment porosity, permeability, chemical and back-scattered electron imaging, and chemical titrations were all used for qualitative and quantitative determination of compositional and injectivity changes. Also, injectivity effects of high flow rate near a wellbore and stress changes were shown on five different cores (two Berea sandstones, two Indiana limestones, and one Dakota sandstone).

  17. EXPLOITATION AND OPTIMIZATION OF RESERVOIR PERFORMANCE IN HUNTON FORMATION, OKLAHOMA

    Energy Technology Data Exchange (ETDEWEB)

    Mohan Kelkar

    2005-02-01

    Hunton formation in Oklahoma has displayed some unique production characteristics. These include high initial water-oil and gas-oil ratios, decline in those ratios over time and temporary increase in gas-oil ratio during pressure build up. The formation also displays highly complex geology, but surprising hydrodynamic continuity. This report addresses three key issues related specifically to West Carney Hunton field and, in general, to any other Hunton formation exhibiting similar behavior: (1) What is the primary mechanism by which oil and gas is produced from the field? (2) How can the knowledge gained from studying the existing fields can be extended to other fields which have the potential to produce? (3) What can be done to improve the performance of this reservoir? We have developed a comprehensive model to explain the behavior of the reservoir. By using available production, geological, core and log data, we are able to develop a reservoir model which explains the production behavior in the reservoir. Using easily available information, such as log data, we have established the parameters needed for a field to be economically successful. We provide guidelines in terms of what to look for in a new field and how to develop it. Finally, through laboratory experiments, we show that surfactants can be used to improve the hydrocarbons recovery from the field. In addition, injection of CO{sub 2} or natural gas also will help us recover additional oil from the field.

  18. Reservoir characterization by multiattribute analysis: The Orito field case

    Directory of Open Access Journals (Sweden)

    Montes Luis

    2010-12-01

    Full Text Available

    In order to characterize the Caballos formation reservoir in the Orito field in the Putumayo basin - Colombia, a multiattribute analysis was applied to a 50 km2 seismic volume along with 16 boreholes. Some properties of the reservoir were reliably estimated and very accurate when compared with well data. The porosity, permeability and volume of shale were calculated in the seismic volume by at least second order multivariate polynomial. A good correlation between porosity and acoustic impedance was observed by means of crossplot analysis performed on properties measured and estimated in cores or borehole logs as well as on properties calculated in the seismic volume. The estimated property values were well behaved according to the rocks physics analysis. With the property maps generated and the geological environments of the reservoir a new interpretation of the Caballos formation was established. High correlation coefficients and low estimated errors point out competence to calculate these three reservoir properties in places far from the influence of the wells. The multiple equation system was established through weighted hierarchical grouping of attributes and their coefficients calculated applying the inverse generalized matrix method.

  19. Standardized surface engineering design of shale gas reservoirs

    Directory of Open Access Journals (Sweden)

    Guangchuan Liang

    2016-01-01

    Full Text Available Due to the special physical properties of shale gas reservoirs, it is necessary to adopt unconventional and standardized technologies for its surface engineering construction. In addition, the surface engineering design of shale gas reservoirs in China faces many difficulties, such as high uncertainty of the gathering and transportation scale, poor adaptability of pipe network and station layout, difficult matching of the process equipments, and boosting production at the late stage. In view of these problems, the surface engineering construction of shale gas reservoirs should follow the principles of “standardized design, modularized construction and skid mounted equipment”. In this paper, standardized surface engineering design technologies for shale gas reservoirs were developed with the “standardized well station layout, universal process, modular function zoning, skid mounted equipment selection, intensive site design, digitized production management” as the core, after literature analysis and technology exploration were carried out. Then its application background and surface technology route were discussed with a typical shale gas field in Sichuan–Chongqing area as an example. Its surface gathering system was designed in a standardized way, including standardized process, the modularized gathering and transportation station, serialized dehydration unit and intensive layout, and remarkable effects were achieved. A flexible, practical and reliable ground production system was built, and a series of standardized technology and modularized design were completed, including cluster well platform, set station, supporting projects. In this way, a system applicable to domestic shale gas surface engineering construction is developed.

  20. Evaluation of field development plans using 3-D reservoir modelling

    Energy Technology Data Exchange (ETDEWEB)

    Seifert, D.; Lewis, J.J.M. [Heriot-Watt Univ., Edinburgh (United Kingdom); Newbery, J.D.H. [Conoco, UK Ltd., Aberdeen (United Kingdom)] [and others

    1997-08-01

    Three-dimensional reservoir modelling has become an accepted tool in reservoir description and is used for various purposes, such as reservoir performance prediction or integration and visualisation of data. In this case study, a small Northern North Sea turbiditic reservoir was to be developed with a line drive strategy utilising a series of horizontal producer and injector pairs, oriented north-south. This development plan was to be evaluated and the expected outcome of the wells was to be assessed and risked. Detailed analyses of core, well log and analogue data has led to the development of two geological {open_quotes}end member{close_quotes} scenarios. Both scenarios have been stochastically modelled using the Sequential Indicator Simulation method. The resulting equiprobable realisations have been subjected to detailed statistical well placement optimisation techniques. Based upon bivariate statistical evaluation of more than 1000 numerical well trajectories for each of the two scenarios, it was found that the wells inclinations and lengths had a great impact on the wells success, whereas the azimuth was found to have only a minor impact. After integration of the above results, the actual well paths were redesigned to meet external drilling constraints, resulting in substantial reductions in drilling time and costs.

  1. Geological model of supercritical geothermal reservoir related to subduction system

    Science.gov (United States)

    Tsuchiya, Noriyoshi

    2017-04-01

    Following the Great East Japan Earthquake and the accident at the Fukushima Daiichi Nuclear power station on 3.11 (11th March) 2011, geothermal energy came to be considered one of the most promising sources of renewable energy for the future in Japan. The temperatures of geothermal fields operating in Japan range from 200 to 300 °C (average 250 °C), and the depths range from 1000 to 2000 m (average 1500 m). In conventional geothermal reservoirs, the mechanical behavior of the rocks is presumed to be brittle, and convection of the hydrothermal fluid through existing network is the main method of circulation in the reservoir. In order to minimize induced seismicity, a rock mass that is "beyond brittle" is one possible candidate, because the rock mechanics of "beyond brittle" material is one of plastic deformation rather than brittle failure. Supercritical geothermal resources could be evaluated in terms of present volcanic activities, thermal structure, dimension of hydrothermal circulation, properties of fracture system, depth of heat source, depth of brittle factures zone, dimension of geothermal reservoir. On the basis of the GIS, potential of supercritical geothermal resources could be characterized into the following four categories. 1. Promising: surface manifestation d shallow high temperature, 2 Probability: high geothermal gradient, 3 Possibility: Aseismic zone which indicates an existence of melt, 4 Potential : low velocity zone which indicates magma input. Base on geophysical data for geothermal reservoirs, we have propose adequate tectonic model of development of the supercritical geothermal reservoirs. To understand the geological model of a supercritical geothermal reservoir, granite-porphyry system, which had been formed in subduction zone, was investigated as a natural analog of the supercritical geothermal energy system. Quartz veins, hydrothermal breccia veins, and glassy veins are observed in a granitic body. The glassy veins formed at 500-550

  2. Sedimentological and Geomorphological Effects of Reservoir Flushing: The Cachi Reservoir, Costa Rica, 1996

    DEFF Research Database (Denmark)

    Brandt, Anders; Swenning, Joar

    1999-01-01

    Physical geography, hydrology, geomorphology, sediment transport, erosion, sedimentation, dams, reservoirs......Physical geography, hydrology, geomorphology, sediment transport, erosion, sedimentation, dams, reservoirs...

  3. Application of Integrated Reservoir Management and Reservoir Characterization to Optimize Infill Drilling

    Energy Technology Data Exchange (ETDEWEB)

    P. K. Pande

    1998-10-29

    Initial drilling of wells on a uniform spacing, without regard to reservoir performance and characterization, must become a process of the past. Such efforts do not optimize reservoir development as they fail to account for the complex nature of reservoir heterogeneities present in many low permeability reservoirs, and carbonate reservoirs in particular. These reservoirs are typically characterized by: o Large, discontinuous pay intervals o Vertical and lateral changes in reservoir properties o Low reservoir energy o High residual oil saturation o Low recovery efficiency

  4. Bent Core Liquid Crystal Polymers and Elastomers

    Science.gov (United States)

    Verduzco, Rafael; Hong, Seung Ho; Harden, John; Jakli, Antal; Sprunt, Sam; Gleeson, Jim

    2010-03-01

    Bent-core liquid crystals (LCs) have a kinked, or bent, molecular shape in contrast to the more common rod-like LCs. Due to their bent molecular shape, bent-core LCs form locally polar clusters, which result in novel LC phases and potentially useful properties such as ferroelectricity. Polymeric bent-core LCs are of particular interest because they can lead to new nanostructured soft materials with confined bent-core LCs. In this work, we investigate the synthesis, nanoscale structure, and physical properties of a variety of bent-core LCs and polymeric bent-core LCs. SAXS reveals the presence of polar clusters over a wide temperature range in the nematic phase for all materials studied, including bent-core side-group LC polymers and bent-core LC elastomers. The presence of locally polar clusters can account for the unexpected physical properties in nematic bent-core LCs, such as enhanced flexoelectricity. Direct flexoelectric measurements on pure bent-core LCs and swollen LCEs show that nematic bent-core materials have a flexoelectric coupling three orders orders of magnitude larger than calamitic LCs. Nematic clusters in bent-core LCs represent an unexpected and potentially useful phenomenon for building responsive LC devices.

  5. Physical properties and structure of fine core-shell particles used as packing materials for chromatography Relationships between particle characteristics and column performance.

    Science.gov (United States)

    Gritti, Fabrice; Leonardis, Irene; Abia, Jude; Guiochon, Georges

    2010-06-11

    The recent development of new brands of packing materials made of fine porous-shell particles, e.g., Halo and Kinetex, has brought great improvements in potential column efficiency, demanding considerable progress in the design of chromatographic instruments. Columns packed with Halo and Kinetex particles provide minimum values of their reduced plate heights of nearly 1.5 and 1.2, respectively. These packing materials have physical properties that set them apart from conventional porous particles. The kinetic performance of 4.6mm I.D. columns packed with these two new materials is analyzed based on the results of a series of nine independent and complementary experiments: low-temperature nitrogen adsorption (LTNA), scanning electron microscopy (SEM), inverse size-exclusion chromatography (ISEC), Coulter counter particle size distributions, pycnometry, height equivalent to a theoretical plate (HETP), peak parking method (PP), total pore blocking method (TPB), and local electrochemical detection across the column exit section (LED). The results of this work establish links between the physical properties of these superficially porous particles and the excellent kinetic performance of columns packed with them. It clarifies the fundamental origin of the difference in the chromatographic performances of the Halo and the Kinetex columns. Copyright 2010 Elsevier B.V. All rights reserved.

  6. Highly efficient perovskite solar cells based on a nanostructured WO3-TiO2 core-shell electron transporting material

    KAUST Repository

    Mahmood, Khalid

    2015-01-01

    Until recently, only mesoporous TiO2 and ZnO were successfully demonstrated as electron transport layers (ETL) alongside the reports of ZrO2 and Al2O3 as scaffold materials in organometal halide perovskite solar cells, largely owing to ease of processing and to high power conversion efficiency. In this article, we explore tungsten trioxide (WO3)-based nanostructured and porous ETL materials directly grown hydrothermally with different morphologies such as nanoparticles, nanorods and nanosheet arrays. The nanostructure morphology strongly influences the photocurrent and efficiency in organometal halide perovskite solar cells. We find that the perovskite solar cells based on WO3 nanosheet arrays yield significantly enhanced photovoltaic performance as compared to nanoparticles and nanorod arrays due to good perovskite absorber infiltration in the porous scaffold and more rapid carrier transport. We further demonstrate that treating the WO3 nanostructures with an aqueous solution of TiCl4 reduces charge recombination at the perovskite/WO3 interface, resulting in the highest power conversion efficiency of 11.24% for devices based on WO3 nanosheet arrays. The successful demonstration of alternative ETL materials and nanostructures based on WO3 will open up new opportunities in the development of highly efficient perovskite solar cells. This journal is © The Royal Society of Chemistry 2015.

  7. SIRIU RESERVOIR, BUZAU RIVER (ROMANIA

    Directory of Open Access Journals (Sweden)

    Daniel Constantin DIACONU

    2008-06-01

    Full Text Available Siriu reservoir, owes it`s creation to the dam built on the river Buzau, in the town which bears the same name. The reservoir has a hydro energetic role, to diminish the maximum flow and to provide water to the localities below. The partial exploitation of the lake, began in 1984; Since that time, the initial bed of the river began to accumulate large quantities of alluvia, reducing the retention capacity of the lake, which had a volume of 125 million m3. The changes produced are determined by many topographic surveys at the bottom of the lake.

  8. Multi-core Microprocessors

    Indian Academy of Sciences (India)

    core processors. Abstract. Multi-core microprocessor is an interconnected set of independentprocessors called cores integrated on a single siliconchip. These processing cores communicate and cooperatewith one another to execute one or more ...

  9. Development of a novel resin-based dental material with dual biocidal modes and sustained release of Ag+ ions based on photocurable core-shell AgBr/cationic polymer nanocomposites.

    Science.gov (United States)

    Cao, Weiwei; Zhang, Yu; Wang, Xi; Chen, Yinyan; Li, Qiang; Xing, Xiaodong; Xiao, Yuhong; Peng, Xuefeng; Ye, Zhiwen

    2017-07-01

    Research on the incorporation of cutting-edge nano-antibacterial agent for designing dental materials with potent and long-lasting antibacterial property is demanding and provoking work. In this study, a novel resin-based dental material containing photocurable core-shell AgBr/cationic polymer nanocomposite (AgBr/BHPVP) was designed and developed. The shell of polymerizable cationic polymer not only provided non-releasing antibacterial capability for dental resins, but also had the potential to polymerize with other methacrylate monomers and prevented nanoparticles from aggregating in the resin matrix. As a result, incorporation of AgBr/BHPVP nanocomposites did not adversely affect the flexural strength and modulus but greatly increased the Vicker's hardness of resin disks. By continuing to release Ag + ions without the impact of anaerobic environment, resins containing AgBr/BHPVP nanoparticles are particularly suitable to combat anaerobic cariogenic bacteria. By reason of the combined bactericidal effect of the contact-killing cationic polymers and the releasing-killing Ag + ions, AgBr/BHPVP-containing resin disks had potent bactericidal activity against S. mutans. The long-lasting antibacterial activity was also achieved through the sustained release of Ag + ions due to the core-shell structure of the nanocomposites. The results of macrophage cytotoxicity showed that the cell viability of dental resins loading less than 1.0 wt% AgBr/BHPVP was close to that of neat resins. The AgBr/BHPVP-containing dental resin with dual bactericidal capability and long term antimicrobial effect is a promising material aimed at preventing second caries and prolonging the longevity of resin composite restorations.

  10. Uranium series isotopes concentration in sediments at San Marcos and Luis L. Leon reservoirs, Chihuahua, Mexico

    International Nuclear Information System (INIS)

    Méndez-García, C.; Montero-Cabrera, M. E.; Renteria-Villalobos, M.; García-Tenorio, R.

    2014-01-01

    Spatial and temporal distribution of the radioisotopes concentrations were determined in sediments near the surface and core samples extracted from two reservoirs located in an arid region close to Chihuahua City, Mexico. At San Marcos reservoir one core was studied, while from Luis L. Leon reservoir one core from the entrance and another one close to the wall were investigated. 232 Th-series, 238 U-series, 40 K and 137 Cs activity concentrations (AC, Bq kg −1 ) were determined by gamma spectrometry with a high purity Ge detector. 238 U and 234 U ACs were obtained by liquid scintillation and alpha spectrometry with a surface barrier detector. Dating of core sediments was performed applying CRS method to 210 Pb activities. Results were verified by 137 Cs AC. Resulting activity concentrations were compared among corresponding surface and core sediments. High 238 U-series AC values were found in sediments from San Marcos reservoir, because this site is located close to the Victorino uranium deposit. Low AC values found in Luis L. Leon reservoir suggest that the uranium present in the source of the Sacramento – Chuviscar Rivers is not transported up to the Conchos River. Activity ratios (AR) 234 U/ 238 U and 238 U/ 226 Ra in sediments have values between 0.9–1.2, showing a behavior close to radioactive equilibrium in the entire basin. 232 Th/ 238 U, 228 Ra/ 226 Ra ARs are witnesses of the different geological origin of sediments from San Marcos and Luis L. Leon reservoirs

  11. Uranium series isotopes concentration in sediments at San Marcos and Luis L. Leon reservoirs, Chihuahua, Mexico

    Science.gov (United States)

    Méndez-García, C.; Renteria-Villalobos, M.; García-Tenorio, R.; Montero-Cabrera, M. E.

    2014-07-01

    Spatial and temporal distribution of the radioisotopes concentrations were determined in sediments near the surface and core samples extracted from two reservoirs located in an arid region close to Chihuahua City, Mexico. At San Marcos reservoir one core was studied, while from Luis L. Leon reservoir one core from the entrance and another one close to the wall were investigated. 232Th-series, 238U-series, 40K and 137Cs activity concentrations (AC, Bq kg-1) were determined by gamma spectrometry with a high purity Ge detector. 238U and 234U ACs were obtained by liquid scintillation and alpha spectrometry with a surface barrier detector. Dating of core sediments was performed applying CRS method to 210Pb activities. Results were verified by 137Cs AC. Resulting activity concentrations were compared among corresponding surface and core sediments. High 238U-series AC values were found in sediments from San Marcos reservoir, because this site is located close to the Victorino uranium deposit. Low AC values found in Luis L. Leon reservoir suggest that the uranium present in the source of the Sacramento - Chuviscar Rivers is not transported up to the Conchos River. Activity ratios (AR) 234U/overflow="scroll">238U and 238U/overflow="scroll">226Ra in sediments have values between 0.9-1.2, showing a behavior close to radioactive equilibrium in the entire basin. 232Th/overflow="scroll">238U, 228Ra/overflow="scroll">226Ra ARs are witnesses of the different geological origin of sediments from San Marcos and Luis L. Leon reservoirs.

  12. Uranium series isotopes concentration in sediments at San Marcos and Luis L. Leon reservoirs, Chihuahua, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Méndez-García, C.; Montero-Cabrera, M. E., E-mail: elena.montero@cimav.edu.mx [Centro de Investigación en Materiales Avanzados, CIMAV, Miguel de Cervantes 120, 31109, Chihuahua, Chihuahua (Mexico); Renteria-Villalobos, M. [Facultad de Zootecnia y Ecología Universidad Autónoma de Chihuahua, Periferico Francisco R. Almada Km 1, 31410, Chihuahua (Mexico); García-Tenorio, R. [Applied Nuclear Physics Group, University of Seville, ETS Arquitectura, Avda. Reina Mercedes s/n, 41012 Seville (Spain)

    2008-01-01

    Spatial and temporal distribution of the radioisotopes concentrations were determined in sediments near the surface and core samples extracted from two reservoirs located in an arid region close to Chihuahua City, Mexico. At San Marcos reservoir one core was studied, while from Luis L. Leon reservoir one core from the entrance and another one close to the wall were investigated. ²³²Th-series, ²³⁸U-series, ⁴⁰K and ¹³⁷Cs activity concentrations (AC, Bq kg⁻¹) were determined by gamma spectrometry with a high purity Ge detector. ²³⁸U and ²³⁴U ACs were obtained by liquid scintillation and alpha spectrometry with a surface barrier detector. Dating of core sediments was performed applying CRS method to ²¹⁰Pb activities. Results were verified by ¹³⁷Cs AC. Resulting activity concentrations were compared among corresponding surface and core sediments. High ²³⁸U-series AC values were found in sediments from San Marcos reservoir, because this site is located close to the Victorino uranium deposit. Low AC values found in Luis L. Leon reservoir suggest that the uranium present in the source of the Sacramento – Chuviscar Rivers is not transported up to the Conchos River. Activity ratios (AR) ²³⁴U/²³⁸U and ²³⁸U/²²⁶Ra in sediments have values between 0.9–1.2, showing a behavior close to radioactive equilibrium in the entire basin. ²³²Th/²³⁸U, ²²⁸Ra/²²⁶Ra ARs are witnesses of the different geological origin of sediments from San Marcos and Luis L. Leon reservoirs.

  13. Observations of Nitrogen Isotope Fractionation in Prestellar Cores

    Science.gov (United States)

    Milam, Stefanie N.; Charnley, Steven B.

    2011-01-01

    Isotopically fractionated material is found in many solar system objects, including meteorites and comets [1]. It is considered, in some cases, to trace interstellar material that was incorporated into the solar system without undergoing significant processing, thus preserving the fractionation. In interstellar molecular clouds, ion-molecule chemistry continually cycles nitrogen between the two main reservoirs - Nand N2 - leading to only minor N-15 enrichments [2]. Charnley and Rodgers [3,4] showed that depletion of CO removes oxygen from the gas and weakens this cycle such that significant N-15 fractionation can occur for N2 and other N-bearing species in such cores. Observations are being conducted at millimeter and submillimeter wavelengths employing various facilities in order to both spatially and spectrally, resolve emission from these cores. A preliminary study to obtain the N-14/N-15 ratio in nitriles was conducted at the Arizona Radio Observatory's 12m telescope on Kitt Peak, AZ. Spectra were obtained at high resolution (0.08 km/s) in order to resolve dynamic properties of each source as well as to resolve hyperfine structure present in certain isotopologues. This study included four dark cloud cores, observed to have varying levels of molecular depletion: Ll521E, Ll498, Ll544, and Ll521F. Previous studies of the N-14/N-15 ratio towards Ll544 were obtained with N2H(+) and NH3 yielding ratios of 446 and greater than 700, respectively [5,6]. The discrepancy observed in these two measurements suggests a strong chemical dependence on the fractionation of nitrogen. Ratios (C,N, and D) obtained from isotopologues for a particular molecule are likely tracing the same chemical heritage and are directly comparable within a given source. Results and comparisons between the protostellar evolutionary state and isomer isotope fractionation as well as between other N-bearing species will be presented.

  14. Isotope Fractionation Studies in Prestellar Cores: The Case of Nitrogen

    Science.gov (United States)

    Milam, Stefanie N.; Charnley, Steven B.

    2011-01-01

    Isotopically fractionated material is found in many solar system objects, including meteorites and comets. It is considered, in some cases, to trace interstellar material that was incorporated into the solar system without undergoing significant processing, thus preserving the fractionation. In interstellar molecular clouds, ion-molecule chemistry continually cycles nitrogen between the two main reservoirs - N and N2 - leading to only minor N-15 enrichments. Charnley and Rodgers showed that depletion of CO removes oxygen from the gas and weakens this cycle such that significant N-15 fractionation can occur for N2 and other N-bearing species in such cores. Observations are being conducted at millimeter and submillimeter wavelengths employing various facilities in order to both spatially and spectrally, resolve emission from these cores. A preliminary study to obtain the N-14/N-15 ratio in nitriles (HCN and HNC) was conducted at the Arizona Radio Observatory's 12m telescope on Kitt Peak, AZ. Spectra were obtained at high resolution (0.08 km/s) in order to resolve dynamic properties of each source as well as to resolve hyperfine structure present in certain isotopologues. This study included four dark cloud cores, observed to have varying levels of molecular depletion: L1521E, L1498, L1544, and L1521F. Previous studies of the N-14/N-15 ratio towards LI544 were obtained with N2H+ and NIH3, yielding ratios of 446 and >700, respectively. The discrepancy observed in these two measurements suggests a strong chemical dependence on the fractionation of nitrogen. Ratios (C,N, and D) obtained from isotopologues for a particular molecule are likely tracing the same chemical heritage and are directly comparable within a given source. Results and comparisons between the protostellar evolutionary state and isomer isotope fractionation as well as between other N-bearing species will be presented.

  15. PERFORM 60 - Prediction of the effects of radiation for reactor pressure vessel and in-core materials using multi-scale modelling - 60 years foreseen plant lifetime

    Science.gov (United States)

    Leclercq, Sylvain; Lidbury, David; Van Dyck, Steven; Moinereau, Dominique; Alamo, Ana; Mazouzi, Abdou Al

    2010-11-01

    In nuclear power plants, materials may undergo degradation due to severe irradiation conditions that may limit their operational life. Utilities that operate these reactors need to quantify the ageing and the potential degradations of some essential structures of the power plant to ensure safe and reliable plant operation. So far, the material databases needed to take account of these degradations in the design and safe operation of installations mainly rely on long-term irradiation programs in test reactors as well as on mechanical or corrosion testing in specialized hot cells. Continuous progress in the physical understanding of the phenomena involved in irradiation damage and continuous progress in computer sciences have now made possible the development of multi-scale numerical tools able to simulate the effects of irradiation on materials microstructure. A first step towards this goal has been successfully reached through the development of the RPV-2 and Toughness Module numerical tools by the scientific community created around the FP6 PERFECT project. These tools allow to simulate irradiation effects on the constitutive behaviour of the reactor pressure vessel low alloy steel, and also on its failure properties. Relying on the existing PERFECT Roadmap, the 4 years Collaborative Project PERFORM 60 has mainly for objective to develop multi-scale tools aimed at predicting the combined effects of irradiation and corrosion on internals (austenitic stainless steels) and also to improve existing ones on RPV (bainitic steels). PERFORM 60 is based on two technical sub-projects: (i) RPV and (ii) internals. In addition to these technical sub-projects, the Users' Group and Training sub-project shall allow representatives of constructors, utilities, research organizations… from Europe, USA and Japan to receive the information and training to get their own appraisal on limits and potentialities of the developed tools. An important effort will also be made to teach young

  16. Reservoir Sedimentation Based on Uncertainty Analysis

    Directory of Open Access Journals (Sweden)

    Farhad Imanshoar

    2014-01-01

    Full Text Available Reservoir sedimentation can result in loss of much needed reservoir storage capacity, reducing the useful life of dams. Thus, sufficient sediment storage capacity should be provided for the reservoir design stage to ensure that sediment accumulation will not impair the functioning of the reservoir during the useful operational-economic life of the project. However, an important issue to consider when estimating reservoir sedimentation and accumulation is the uncertainty involved in reservoir sedimentation. In this paper, the basic factors influencing the density of sediments deposited in reservoirs are discussed, and uncertainties in reservoir sedimentation have been determined using the Delta method. Further, Kenny Reservoir in the White River Basin in northwestern Colorado was selected to determine the density of deposits in the reservoir and the coefficient of variation. The results of this investigation have indicated that by using the Delta method in the case of Kenny Reservoir, the uncertainty regarding accumulated sediment density, expressed by the coefficient of variation for a period of 50 years of reservoir operation, could be reduced to about 10%. Results of the Delta method suggest an applicable approach for dead storage planning via interfacing with uncertainties associated with reservoir sedimentation.

  17. PERFORM 60: Prediction of the effects of radiation for reactor pressure vessel and in-core materials using multi-scale modelling - 60 years foreseen plant lifetime

    International Nuclear Information System (INIS)

    Al Mazouzi, A.; Alamo, A.; Lidbury, D.; Moinereau, D.; Van Dyck, S.

    2011-01-01

    Highlights: → Multi-scale and multi-physics modelling are adopted by PERFORM 60 to predict irradiation damage in nuclear structural materials. → PERFORM 60 allows to Consolidate the community and improve the interaction between universities/industries and safety authorities. → Experimental validation at the relevant scale is a key for developing the multi-scale modelling methodology. - Abstract: In nuclear power plants, materials undergo degradation due to severe irradiation conditions that may limit their operational lifetime. Utilities that operate these reactors need to quantify the ageing and potential degradation of certain essential structures of the power plant to ensure their safe and reliable operation. So far, the monitoring and mitigation of these degradation phenomena rely mainly on long-term irradiation programs in test reactors as well as on mechanical or corrosion testing in specialized hot cells. Continuous progress in the physical understanding of the phenomena involved in irradiation damage and progress in computer sciences have now made possible the development of multi-scale numerical tools able to simulate the materials behaviour in a nuclear environment. Indeed, within the PERFECT project of the EURATOM framework program (FP6), a first step has been successfully reached through the development of a simulation platform that contains several advanced numerical tools aiming at the prediction of irradiation damage in both the reactor pressure vessel (RPV) and its internals using available, state-of-the-art-knowledge. These tools allow simulation of irradiation effects on the nanostructure and the constitutive behaviour of the RPV low alloy steels, as well as their fracture mechanics properties. For the more highly irradiated reactor internals, which are commonly produced using austenitic stainless steels, the first partial models were established, describing radiation effects on the nanostructure and providing a first description of the

  18. Data assimilation in reservoir management

    NARCIS (Netherlands)

    Rommelse, J.R.

    2009-01-01

    The research presented in this thesis aims at improving computer models that allow simulations of water, oil and gas flows in subsurface petroleum reservoirs. This is done by integrating, or assimilating, measurements into physics-bases models. In recent years petroleum technology has developed

  19. Reservoirs in the United States

    Science.gov (United States)

    Harbeck, G. Earl

    1948-01-01

    Man has engaged in the control of flowing water since history began. Among his early recorded efforts were reservoirs for muncipal water-supplies constructed near ancient Jerusalem to store water which was brought there in masonry conduits. 1/  Irrigation was practiced in Egypt as early as 2000 B. C. There the "basin system" was used from ancient times until the 19th century. The land was divided , into basins of approximately 40,000 acres, separated by earthen dikes. 2/  Flood waters of the Nile generally inundated the basins through canals, many of which were built by the Pharaohs. Even then the economic consequences of a deficient annual flood were recognized. Lake Maeris, which according to Herodotus was an ancient storage reservoir, is said to have had an area of 30,000 acres. In India, the British found at the time of their occupancy of the Presidency of Madras about 50,000 reservoirs for irrigation, many believed to be of ancient construction. 3/ During the period 115-130 A. D. reservoirs were built to improve the water-supply of Athens. Much has been written concerning the elaborate collection and distribution system built to supply Rome, and parts of it remain to this day as monuments to the engineering skill employed by the Romans in solving the problem of large-scale municipal water-supplies.

  20. Reasons for reservoir effect variability

    DEFF Research Database (Denmark)

    Philippsen, Bente

    2013-01-01

    , aquatic plants and fish from the rivers Alster and Trave range between zero and about 3,000 radiocarbon years. The reservoir age of water DIC depends to a large extent on the origin of the water and is for example correlated with precipitation amounts. These short-term variations are smoothed out in water...

  1. Tracing the External Origin of the AGN Gas Fueling Reservoir

    Directory of Open Access Journals (Sweden)

    Sandra I. Raimundo

    2018-01-01

    Full Text Available Near-infrared observations of the active galaxy MCG–6-30-15 provide strong evidence that its molecular gas fueling reservoir is of external origin. MCG–6-30-15 has a counter-rotating core of stars within its central 400 pc and a counter-rotating disc of molecular gas that extends as close as ~50–100 pc from the central black hole. The gas counter-rotation establishes that the gas reservoir in the center of the galaxy originates from a past external accretion event. In this contribution we discuss the gas and stellar properties of MCG–6-30-15, its past history and how the findings on this galaxy can be used to understand AGN fueling in S0 galaxies with counter-rotating structures.

  2. Prediction of Gas Injection Performance for Heterogeneous Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Blunt, Martin J.; Orr, Jr., Franklin M.

    1999-12-20

    This report describes research carried out in the Department of Petroleum Engineering at Stanford University from September 1998 - September 1998 under the third year of a three-year Department of Energy (DOE) grant on the ''Prediction of Gas Injection Performance for Heterogeneous Reservoirs''. The research effort is an integrated study of the factors affecting gas injection, from the pore scale to the field scale, and involves theoretical analysis, laboratory experiments and numerical simulation. The research is divided into four main areas: (1) Pore scale modeling of three-phase flow in porous media; (2) Laboratory experiments and analysis of factors influencing gas injection performance at the core scale with an emphasis on the fundamentals of three-phase flow; (3) Benchmark simulations of gas injection at the field scale; and (4) Development of streamline-based reservoir simulator.

  3. Potosi Reservoir Modeling; History and Recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Valerie; Leetaru, Hannes

    2014-09-30

    As a part of a larger project co-funded by the United States Department of Energy (US DOE) to evaluate the potential of formations within the Cambro-Ordovician strata above the Mt. Simon as potential targets for carbon sequestration in the Illinois and Michigan Basins, the Illinois Clean Coal Institute (ICCI) requested Schlumberger to evaluate the potential injectivity and carbon dioxide (CO₂) plume size of the Cambrian Potosi Formation. The evaluation of this formation was accomplished using wireline data, core data, pressure data, and seismic data from two projects: the US DOE-funded Illinois Basin–Decatur Project being conducted by the Midwest Geological Sequestration Consortium in Macon County, Illinois, as well as data from the Illinois – Industrial Carbon Capture and Sequestration (IL-ICCS) project funded through the American Recovery and Reinvestment Act. In 2010, technical performance evaluations on the Cambrian Potosi Formation were performed through reservoir modeling. The data included formation tops from mud logs, well logs from the Verification Well 1 (VW1) and the Injection Well (CCS1), structural and stratigraphic formation from three dimensional (3D) seismic data, and field data from several waste water injection wells for the Potosi Formation. The intention was for two million tonnes per annum (MTPA) of CO₂ to be injected for 20 years into the Potosi Formation. In 2013, updated reservoir models for the Cambrian Potosi Formation were evaluated. The data included formation tops from mud logs, well logs from the CCS1, VW1, and Verification Well 2 (VW2) wells, structural and stratigraphic formation from a larger 3D seismic survey, and field data from several waste water injection wells for Potosi Formation. The objective is to simulate the injection of CO₂ at a rate 3.5 million tons per annum (3.2 million tonnes per annum [MTPA]) for 30 years 106 million tons (96 MT total) into the Potosi Formation. The Potosi geomodeling efforts have evolved

  4. Sediment deposition and trends and transport of phosphorus and other chemical constituents, Cheney Reservoir watershed, south-central Kansas

    Science.gov (United States)

    Mau, D.P.

    2001-01-01

    Sediment deposition, water-quality trends, and mass transport of phosphorus, nitrogen, selected trace elements, and selected pesticides within the Cheney Reservoir watershed in south-central Kansas were investigated using bathymetric survey data and reservoir bottom-sediment cores. Sediment loads in the reservoir were investigated by comparing 1964 topographic data to 1998 bathymetric survey data. Approximately 7,100 acre-feet of sediment deposition occurred in Cheney Reservoir from 1965 through 1998. As of 1998, sediment had filled 27 percent of the reservoir's inactive conservation storage pool, which is less than the design estimate of 34 percent. Mean annual sediment deposition was 209 acre-feet per year, or 0.22 acre-feet per year per square mile, and the mean annual sediment load was 453 million pounds per year. During the 3-year period from 1997 through 1999, 23 sediment cores were collected from the reservoir, and subsamples were analyzed for nutrients (phosphorus and nitrogen species), selected trace elements, and selected organic pesticides. Mean concentrations of total phosphorus in reservoir bottom sediment ranged from 94 milligrams per kilogram at the upstream end of the reservoir to 710 milligrams per kilogram farther downstream near the reservoir dam. The mean concentration for all sites was 480 milligrams per kilogram. Total phosphorus concentrations were greatest when more silt- and clay-sized particles were present. The implications are that if anoxic conditions (inadequate oxygen) occur near the dam, phosphorus could be released from the sediment and affect the drinking-water supply. Analysis of selected cores also indicates that total phosphorus concentrations in the reservoir sediment increased over time and were probably the result of nonpoint-source activities in the watershed, such as increased fertilizer use and livestock production. Mean annual phosphorus loading to Cheney Reservoir was estimated to be 226,000 pounds per year on the basis

  5. Reservoir Cathode for Electric Space Propulsion Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a reservoir cathode to improve performance in both ion and Hall-effect thrusters. We propose to adapt our existing reservoir cathode technology to this...

  6. 49 CFR 236.792 - Reservoir, equalizing.

    Science.gov (United States)

    2010-10-01

    ... Reservoir, equalizing. An air reservoir connected with and adding volume to the top portion of the equalizing piston chamber of the automatic brake valve, to provide uniform service reductions in brake pipe...

  7. Dissolved methane in Indian freshwater reservoirs

    Digital Repository Service at National Institute of Oceanography (India)

    Narvenkar, G.; Naqvi, S.W.A.; Kurian, S.; Shenoy, D.M.; Pratihary, A.K.; Naik, H.; Patil, S.; Sarkar, A.; Gauns, M.

    Emission of methane (CH4), a potent greenhouse gas, from tropical reservoirs is of interest because such reservoirs experience conducive conditions for CH4 production through anaerobic microbial activities. It has been suggested that Indian...

  8. The Methane Hydrate Reservoir System

    Science.gov (United States)

    Flemings, P. B.; Liu, X.

    2007-12-01

    We use multi phase flow modeling and field examples (Hydrate Ridge, offshore Oregon and Blake Ridge, offshore North Carolina) to demonstrate that the methane hydrate reservoir system links traditional and non- traditional hydrocarbon system components: free gas flow is a fundamental control on this system. As in a traditional hydrocarbon reservoir, gas migrates into the hydrate reservoir as a separate phase (secondary migration) where it is trapped in a gas column beneath the base of the hydrate layer. With sufficient gas supply, buoyancy forces exceed either the capillary entry pressure of the cap rock or the fracture strength of the cap rock, and gas leaks into the hydrate stability zone, or cap rock. When gas enters the hydrate stability zone and forms hydrate, it becomes a very non traditional reservoir. Free gas forms hydrate, depletes water, and elevates salinity until pore water is too saline for further hydrate formation: salinity and hydrate concentration increase upwards from the base of the regional hydrate stability zone (RHSZ) to the seafloor and the base of the hydrate stability zone has significant topography. Gas chimneys couple the free gas zone to the seafloor through high salinity conduits that are maintained at the three-phase boundary by gas flow. As a result, significant amounts of gaseous methane can bypass the RHSZ, which implies a significantly smaller hydrate reservoir than previously envisioned. Hydrate within gas chimneys lie at the three-phase boundary and thus small increases in temperature or decreases in pressure can immediately transport methane into the ocean. This type of hydrate deposit may be the most economical for producing energy because it has very high methane concentrations (Sh > 70%) located near the seafloor, which lie on the three-phase boundary.

  9. Application of reservoir characterization and advanced technology to improve recovery and economic in a lower quality shallow shelf carbonate reservoir. First quarter 1995

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, A.M.

    1995-05-04

    The focus of the project is to show that the use of advanced technology can improve the economics of CO{sub 2} projects in low permeability reservoirs. The approach involves the use of tomography, 3-D seismic and detailed petrophysical descriptions to enhance reservoir characterization. Cyclic CO{sub 2} stimulations and model designed frac treatments will be used to increase and facilitate oil recovery to improve project economics. The detailed reservoir characterization will be used to create a geological model for use in simulation to arrive at an optimum operating plan to be instituted during the second budget period. Objectives to be accomplished during the third quarter include: (1) Complete petrophysical description on cores from observation wells. (2) Apply petrophysical data to geologic model. (3) Conduct additional laboratory analysis on cores and fluids. (4) Refine 3-D seismic interpretations. (5) Complete tomography surveys. (6) Process tomography data. (7) Establish relationship between seismic and tomography interpretations. (8) Conduct preliminary simulator runs with improved geologic model. (9) Evaluate results of cyclic CO{sub 2} stimulation treatments. (10) Design frac treatment for linear flood fronts. All of the above objectives were worked on during the current quarter and the overall project is fairly well on schedule. The area of greatest concern time-wise is reservoir simulation. The simulator depends on the geologic model, which in turn depends on the petrophysical, 3-D seismic and tomography interpretations. Hence, the final geologic model won`t be available until all of the reservoir characterization work is completed.

  10. A Calculation of Nuclear Heating by Activation Product of Structure Materials for the In-core Irradiation Hole in the HANARO

    International Nuclear Information System (INIS)

    Noh, Tae Yang; Park, B. G.; Kim, M. S.

    2016-01-01

    Only delayed gamma heating is considered in this paper. Contribution of the delayed gamma heating is expected to be negligible for the reactor power. For the neutron irradiation, however, the contribution of delayed gamma heating is not negligible issue, and it should be evaluated for safety analysis. Additionally, in the case of temperature-sensitive irradiation targets, the delayed gamma heating should be evaluated precisely. For the HANARO, the delayed gamma heating has been evaluated by modifying the library data of the calculation code or by assuming the heating to be conservative value based on prompt gamma heating. For the method of modifying the library data, however, it should be able to estimate isotopes which contribute to heat generation exactly. And furthermore, it should be concerned to determine modified emission yield of gamma-rays depending on the half-life. For the method of assuming conservative value, it is hard to determine whether the assumed heating value is enough conservative or not. In this study, a methodology for evaluation of nuclear heating by structure materials irradiated for a long time is established with the ORIGEN and MCNP codes. And this method is applied to determine the nuclear heating of the RI capsule in the IR2 irradiation hole in the HANARO. In this paper, the methodology for evaluation of heat generation by irradiated structure materials was established by using the ORIGEN and MCNP codes. From this result, the contribution by farther structures was expected to be negligible. Meanwhile, heat generation by delayed gamma-ray was calculated less than 0.03% of heat generation by prompt radiations. The result of this study indicates that there are some remaining issues for the real situation of the neutron irradiation at HANARO.

  11. Glacial ice cores: A model system for developing extraterrestrial decontamination protocols

    Science.gov (United States)

    Christner, Brent C.; Mikucki, Jill A.; Foreman, Christine M.; Denson, Jackie; Priscu, John C.

    2005-04-01

    Evidence gathered from spacecraft orbiting Mars has shown that water ice exists at both poles and may form a large subsurface reservoir at lower latitudes. The recent exploration of the martian surface by unmanned landers and surface rovers, and the planned missions to eventually return samples to Earth have raised concerns regarding both forward and back contamination. Methods to search for life in these icy environments and adequate protocols to prevent contamination can be tested with earthly analogues. Studies of ice cores on Earth have established past climate changes and geological events, both globally and regionally, but only recently have these results been correlated with the biological materials (i.e., plant fragments, seeds, pollen grains, fungal spores, and microorganisms) that are entrapped and preserved within the ice. The inclusion of biology into ice coring research brings with it a whole new approach towards decontamination. Our investigations on ice from the Vostok core (Antarctica) have shown that the outer portion of the cores have up to 3 and 2 orders of magnitude higher bacterial density and dissolved organic carbon (DOC) than the inner portion of the cores, respectively, as a result of drilling and handling. The extreme gradients that exist between the outer and inner portion of these samples make contamination a very relevant aspect of geomicrobiological investigations with ice cores, particularly when the actual numbers of ambient bacterial cells are low. To address this issue and the inherent concern it raises for the integrity of future investigations with ice core materials from terrestrial and extraterrestrial environments, we employed a procedure to monitor the decontamination process in which ice core surfaces are painted with a solution containing a tracer microorganism, plasmid DNA, and fluorescent dye before sampling. Using this approach, a simple and direct method is proposed to verify the authenticity of geomicrobiological

  12. Reservoir characterization of the Snorre Field

    OpenAIRE

    Gjestvang, Jørgen

    2016-01-01

    Master's thesis in Petroleum engineering The fluvial sandstone in the Snorre field consists of braided to meander streams deposited in arid and in humid climate that show a clear differences in the sedimentology and reservoir properties, especially the silt content in large part of the reservoir which decrease the reservoir properties and water saturation. The heterogeneity of these fluvial formations combined with the faulting history makes this reservoir highly complex with many local an...

  13. Reservoir resistivity characterization incorporating flow dynamics

    KAUST Repository

    Arango, Santiago

    2016-04-07

    Systems and methods for reservoir resistivity characterization are provided, in various aspects, an integrated framework for the estimation of Archie\\'s parameters for a strongly heterogeneous reservoir utilizing the dynamics of the reservoir are provided. The framework can encompass a Bayesian estimation/inversion method for estimating the reservoir parameters, integrating production and time lapse formation conductivity data to achieve a better understanding of the subsurface rock conductivity properties and hence improve water saturation imaging.

  14. Reservoir characterization of the Mt. Simon Sandstone, Illinois Basin, USA

    Science.gov (United States)

    Frailey, S.M.; Damico, J.; Leetaru, H.E.

    2011-01-01

    The integration of open hole well log analyses, core analyses and pressure transient analyses was used for reservoir characterization of the Mt. Simon sandstone. Characterization of the injection interval provides the basis for a geologic model to support the baseline MVA model, specify pressure design requirements of surface equipment, develop completion strategies, estimate injection rates, and project the CO2 plume distribution.The Cambrian-age Mt. Simon Sandstone overlies the Precambrian granite basement of the Illinois Basin. The Mt. Simon is relatively thick formation exceeding 800 meters in some areas of the Illinois Basin. In the deeper part of the basin where sequestration is likely to occur at depths exceeding 1000 m, horizontal core permeability ranges from less than 1 ?? 10-12 cm 2 to greater than 1 ?? 10-8 cm2. Well log and core porosity can be up to 30% in the basal Mt. Simon reservoir. For modeling purposes, reservoir characterization includes absolute horizontal and vertical permeability, effective porosity, net and gross thickness, and depth. For horizontal permeability, log porosity was correlated with core. The core porosity-permeability correlation was improved by using grain size as an indication of pore throat size. After numerous attempts to identify an appropriate log signature, the calculated cementation exponent from Archie's porosity and resistivity relationships was used to identify which porosity-permeability correlation to apply and a permeability log was made. Due to the relatively large thickness of the Mt. Simon, vertical permeability is an important attribute to understand the distribution of CO2 when the injection interval is in the lower part of the unit. Only core analyses and specifically designed pressure transient tests can yield vertical permeability. Many reservoir flow models show that 500-800 m from the injection well most of the CO2 migrates upward depending on the magnitude of the vertical permeability and CO2 injection

  15. IMPROVING CO2 EFFICIENCY FOR RECOVERING OIL IN HETEROGENEOUS RESERVOIRS

    International Nuclear Information System (INIS)

    Reid B. Grigg; Robert K. Svec; Zheng-Wen Zeng; Liu Yi; Baojun Bai

    2004-01-01

    A three-year contract for the project, DOE Contract No. DE-FG26-01BC15364, ''Improving CO 2 Efficiency for Recovering Oil in Heterogeneous Reservoirs'', was started on September 28, 2001. This project examines three major areas in which CO 2 flooding can be improved: fluid and matrix interactions, conformance control/sweep efficiency, and reservoir simulation for improved oil recovery. The project has received a one-year, no-cost extension to September 27, 2005. During this extra time additional deliverables will be (1) the version of MASTER that has been debugged and a foam option added for CO 2 mobility control and (2) adsorption/desorption data on pure component minerals common in reservoir rock that will be used to improve predictions of chemical loss to adsorption in reservoirs. This report discusses the activity during the six-month period covering October 1, 2003 through March 31, 2004 that comprises the first and second fiscal quarters of the project's third year. During this period of the project several areas have advanced: reservoir fluid/rock interactions and their relationships to changing injectivity, and surfactant adsorption on quarried core and pure component granules, foam stability, and high flow rate effects. Presentations and papers included: a papers covered in a previous report was presented at the fall SPE ATCE in Denver in October 2003, a presentation at the Southwest ACS meeting in Oklahoma City, presentation on CO 2 flood basic behavior at the Midland Annual CO 2 Conference December 2003; two papers prepared for the biannual SPE/DOE Symposium on IOR, Tulsa, April 2004; one paper accepted for the fall 2004 SPE ATCE in Houston; and a paper submitted to an international journal Journal of Colloid and Interface Science which is being revised after peer review

  16. Thermochemical sulphate reduction can improve carbonate petroleum reservoir quality

    Science.gov (United States)

    Jiang, Lei; Worden, Richard H.; Yang, Changbing

    2018-02-01

    Interest in the creation of secondary pore spaces in petroleum reservoirs has increased because of a need to understand deeper and more complex reservoirs. The creation of new secondary porosity that enhances overall reservoir quality in deeply buried carbonate reservoirs is controversial and some recent studies have concluded it is not an important phenomenon. Here we present petrography, geochemistry, fluid inclusion data, and fluid-rock interaction reaction modeling results from Triassic Feixianguan Formation, Sichuan Basin, China, core samples and explore the relative importance of secondary porosity due to thermochemical sulphate reduction (TSR) during deep burial diagenesis. We find that new secondary pores result from the dissolution of anhydrite and possibly from dissolution of the matrix dolomite. Assuming porosity before TSR was 16% and the percentage of anhydrite was 6%, modelling shows that, due to TSR, 1.6% additional porosity was created that led to permeability increasing from 110 mD (range 72-168 mD within a 95% confidence interval) to 264 mD (range 162-432 mD within a 95% confidence interval). Secondary porosity results from the density differences between reactant anhydrite and product calcite, the addition of new water during TSR, and the generation of acidity during the reaction of new H2S with the siderite component in pre-existing dolomite in the reservoir. Fluid pressure was high during TSR, and approached lithostatic pressure in some samples; this transient overpressure may have led to the maintenance of porosity due to the inhibition of compactional processes. An additional 1.6% porosity is significant for reserve calculations, especially considering that it occurs in conjunction with elevated permeability that results in faster flow rates to the production wells.

  17. Tenth workshop on geothermal reservoir engineering: proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-22

    The workshop contains presentations in the following areas: (1) reservoir engineering research; (2) field development; (3) vapor-dominated systems; (4) the Geysers thermal area; (5) well test analysis; (6) production engineering; (7) reservoir evaluation; (8) geochemistry and injection; (9) numerical simulation; and (10) reservoir physics. (ACR)

  18. 32 CFR 644.4 - Reservoir Projects.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Reservoir Projects. 644.4 Section 644.4 National... HANDBOOK Project Planning Civil Works § 644.4 Reservoir Projects. (a) Joint land acquisition policy for reservoir projects. The joint policies of the Department of the Interior and the Department of the Army...

  19. Application of magnetic method to assess the extent of high temperature geothermal reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Soengkono, S.; Hochstein, M.P.

    1995-01-26

    The extent of thermally altered rocks in high temperature geothermal reservoirs hosted by young volcanic rocks can be assessed from magnetic surveys. Magnetic anomalies associated with many geothermal field in New Zealand and Indonesia can be interpreted in terms of thick (up to 1 km) demagnetized reservoir rocks. Demagnetization of these rocks has been confirmed by core studies and is caused by hydrothermal alteration produced from fluid/rock interactions. Models of the demagnetized Wairakei (NZ) and Kamojang (Indonesia) reservoirs are presented which include the productive areas. Magnetic surveys give fast and economical investigations of high temperature prospects if measurements are made from the air. The magnetic interpretation models can provide important constraints for reservoir models. Magnetic ground surveys can also be used to assess the extent of concealed near surface alteration which can be used in site selection of engineering structures.

  20. Rese