Nonlinear behavior of matrix-inclusion composites under high confining pressure: application to concrete and mortar

Science.gov (United States)

Le, Tuan Hung; Dormieux, Luc; Jeannin, Laurent; Burlion, Nicolas; Barthélémy, Jean-François

2008-08-01

This paper is devoted to a micromechanics-based simulation of the response of concrete to hydrostatic and oedometric compressions. Concrete is described as a composite made up of a cement matrix in which rigid inclusions are embedded. The focus is put on the role of the interface between matrix and inclusion which represent the interfacial transition zone (ITZ). A plastic behavior is considered for both the matrix and the interfaces. The effective response of the composite is derived from the modified secant method adapted to the situation of imperfect interfaces. To cite this article: T.H. Le et al., C. R. Mecanique 336 (2008).

Heterogenous Oxygen Isotopic Composition of a Complex Wark-Lovering Rim and the Margin of a Refractory Inclusion from Leoville

Science.gov (United States)

Simon, J. I.; Matzel, J. E. P.; Simon, S. B.; Weber, P. K.; Grossman, L.; Ross, D. K.; Hutcheon, I. D.

2014-01-01

Wark-Lovering (WL) rims [1] surrounding many refractory inclusions represent marker events in the early evolution of the Solar System in which many inclusions were exposed to changes in pressure [2], temperature [3], and isotopic reservoirs [4-7]. The effects of these events can be complex, not only producing mineralogical variability of WL rims [2], but also leading to mineralogical [8-10] and isotopic [7, 11, 12] changes within inclusion interiors. Extreme oxygen isotopic heterogeneity measured in CAIs has been explained by mixing between distinct oxygen gas reservoirs in the nebula [13]. Some WL rims contain relatively simple mineral layering and/or are isotopically homogeneous [14, 15]. As part of a larger effort to document and understand the modifications observed in some CAIs, an inclusion (L6) with a complex WL rim from Leoville, a member of the reduced CV3 subgroup was studied. Initial study of the textures and mineral chemistry was presented by [16]. Here we present NanoSIMS oxygen isotopic measurements to complement these petrologic observations.

MUSIC-type imaging of a thin penetrable inclusion from its multi-static response matrix

International Nuclear Information System (INIS)

Park, Won-Kwang; Lesselier, Dominique

2009-01-01

The imaging of a thin inclusion, with dielectric and/or magnetic contrasts with respect to the embedding homogeneous medium, is investigated. A MUSIC-type algorithm operating at a single time-harmonic frequency is developed in order to map the inclusion (that is, to retrieve its supporting curve) from scattered field data collected within the multi-static response matrix. Numerical experiments carried out for several types of inclusions (dielectric and/or magnetic ones, straight or curved ones), mostly single inclusions and also two of them close by as a straightforward extension, illustrate the pros and cons of the proposed imaging method

MUSIC-type imaging of a thin penetrable inclusion from its multi-static response matrix

Science.gov (United States)

Park, Won-Kwang; Lesselier, Dominique

2009-07-01

The imaging of a thin inclusion, with dielectric and/or magnetic contrasts with respect to the embedding homogeneous medium, is investigated. A MUSIC-type algorithm operating at a single time-harmonic frequency is developed in order to map the inclusion (that is, to retrieve its supporting curve) from scattered field data collected within the multi-static response matrix. Numerical experiments carried out for several types of inclusions (dielectric and/or magnetic ones, straight or curved ones), mostly single inclusions and also two of them close by as a straightforward extension, illustrate the pros and cons of the proposed imaging method.

Study of non-metallic inclusion sources in steel

International Nuclear Information System (INIS)

Khons, Ya.; Mrazek, L.

1976-01-01

A study of potential inclusion sources was carried out at the Tvinec steel plant using an unified labelling procedure for different sources. A lanthanum oxide labelling method has been used for refractories with the subsequent La determination in steel by the neutron activation analysis. Samarium and cerium oxides and the 141 Ce radionuclide have been used in conjunction with the testing. The following sources of exogenous inclusions have been studied: 1)Refractory material comprising fireclay and corundum for steel-teeming trough in open-heart furnaces; 2) Fireclay bottom-pouring refractories; 3) Steel-teeming laddle lining; 4) Heat-insulating and exothermic compounds for steel ingots; 5) Vacuum treatment plant lining; 6) Open-hearth and electric arc furnace slag. The major oxide inclusion source in steel was found to be represented by the furnace slag, since it forms about 40 p.c. of all oxide inclusions. The contributions of the remaining sources did not exceede 5 p.c. each

On Inclusion-Matrix Interfacial Stresses in Composites Containing Phase-Transforming Phases

International Nuclear Information System (INIS)

Wang, Y.-C.; Ko, C.-C.

2010-01-01

Recent development in composites containing phase-transforming particles, such as vanadium dioxide or barium titanate, reveals the overall stiffness and viscoelastic damping of the composites may be unbounded. Negative stiffness is induced from phase transformation predicted by the Landau phase transformation theory. Although this unbounded phenomenon is theoretically supported with the composite homogenization theory, detailed stress analyses of the composites are still lacking. In this work, we analyze the two-dimensional plane stress elasticity problem of a square plate containing a circular inclusion, under the assumption that the Young's modulus of the inclusion is negative. Assumption of negative stiffness is a priori in the present analysis. A static loading condition is adopted to estimate the effective modulus of the composites by the ratio of applied stress to averaged strain on the loading edges. It is found that the interfacial stresses between the circular inclusion and matrix increase dramatically when the negative stiffness is so tuned that overall stiffness is unbounded. Furthermore, it is found that stress distributions in the inclusion are not uniform, contrary to Eshelby's theorem, which states, for two-phase, infinite composites, the inclusion's stress distribution is uniform when the shape of the inclusion has higher symmetry than an ellipse. The rationale for this nonuniform stress distributions is due to nonlocal effects induced from negative stiffness.

Long-term evaluation of treatment of chronic, therapeutically refractory tinnitus by neurostimulation

NARCIS (Netherlands)

Staal, M. J.; Holm, A. F.; Mooij, J. J. A.; Albers, F. W. J.; Bartels, H.

2007-01-01

Objective: Long-term evaluation of treatment of chronic, therapeutically refractory tinnitus by means of chronic electrical stimulation of the vestibulocochlear nerve. Patients: Inclusion criteria were severe, chronic, therapeutically refractory, unilateral tinnitus and severe hearing loss at the

A 197Au and 57Fe Moessbauer study of the roasting of refractory gold ores

International Nuclear Information System (INIS)

Wagner, F.E.; Marion, P.

1989-01-01

The transformation of chemically bound gold into metallic gold during industrial scale roasting of an arsenical gold ore concentrate from the Fairview Mine, Eastern Transvaal, has been studied quantitatively by 197 Au Moessbauer spectroscopy. The iron compounds in the concentrate, mainly FeAsS and FeS 2 , and their transformations during roasting have been studied by 57 Fe Moessbauer spectroscopy. The bound gold is found to convert into the metal in parallel to the decomposition of FeAsS and the increase in cyanide leachability. This shows that the refractory character of the ore is caused by the chemical bonding of the gold rather than by the physical inclusion of small, discrete metallic particles in the matrix of FeAsS or FeS 2 . The ratio of the f-factors of gold bound in the FeAsS component of a refractory ore and of metallic gold was determined to be f(Au:FeAsS)/f(Au)=1.48 ± 0.09. (orig.)

Tungsten and refractory metals 3, proceedings

International Nuclear Information System (INIS)

Bose, A.; Dowding, R.J.

1996-01-01

The Third International Conference on Tungsten and Refractory Metals was held in Greater Washington DC at the McLean Hilton, McLean Virginia, on November 15--16, 1995. This meeting was the third in a series of conferences held in the Washington DC area. The first meeting was in 1992 and was entitled ''International Conference on Tungsten and Tungsten Alloys.'' In 1994, the scope of the meeting was expanded to include other refractory metals such as molybdenum, iridium, rhenium, tantalum and niobium. The tremendous success of that meeting was the primary motivation for this Conference. The broader scope (the inclusion of other refractory metals and alloys) of the Conference was kept intact for this meeting. In fact, it was felt that the developments in the technology of these materials required a common forum for the interchange of current research information. The papers presented in this meeting examined the rapid advancements in the technology of refractory metals, with special emphasis on the processing, structure, and properties. Among the properties there was emphasis on both quasi-static and dynamic rates. Another topic that received considerable interest was the area of refractory carbides and tungsten-copper composites. One day of concurrent session was necessary to accommodate all of the presentations

Membrane and inclusion body targeting of lyssavirus matrix proteins.

Science.gov (United States)

Pollin, Reiko; Granzow, Harald; Köllner, Bernd; Conzelmann, Karl-Klaus; Finke, Stefan

2013-02-01

Lyssavirus matrix proteins (M) support virus budding and have accessory functions that may contribute to host cell manipulation and adaptation to specific hosts. Here, we show that rabies virus (RABV) and European Bat Lyssavirus Type 1 (EBLV-1) M proteins differ in targeting and accumulation at cellular membranes. In contrast to RABV M, EBLV-1 M expressed from authentic EBLV-1 or chimeric RABV accumulated at the Golgi apparatus. Chimeric M proteins revealed that Golgi association depends on the integrity of the entire EBLV-1 M protein. Since RABV and EBLV-1 M differ in the use of cellular membranes for particle formation, differential membrane targeting and transport of M might determine the site of virus production. Moreover, both RABV and EBLV-1 M were for the first time detected within the nucleus and in Negri body-like inclusions bodies. Whereas nuclear M may imply hitherto unknown functions of lyssavirus M in host cell manipulation, the presence of M in inclusion bodies may correlate with regulatory functions of M in virus RNA synthesis. The data strongly support a model in which targeting of lyssavirus M proteins to distinctintracellular sites is a key determinant of diverse features in lyssavirus replication, host adaptation and pathogenesis. © 2012 Blackwell Publishing Ltd.

Effect of rigid inclusions on sintering

International Nuclear Information System (INIS)

Rahaman, M.N.; De Jonghe, L.C.

1988-01-01

The predictions of recent theoretical studies on the effect of inert, rigid inclusions on the sintering of ceramic powder matrices are examined and compared with experimental data. The densification of glass matrix composites with inclusion volume fractions of ≤0.15 can be adequately explained by Scherer's theory for viscous sintering with rigid inclusions. Inclusions cause a vast reduction in the densification rates of polycrystalline matrix composites even at low inclusion volume fractions. Models put forward to explain the sintering of polycrystalline matrix composites are discussed

Interface Analyses Between a Case-Hardened Ingot Casting Steel and Carbon-Containing and Carbon-Free Refractories

Science.gov (United States)

Fruhstorfer, Jens; Dudczig, Steffen; Rudolph, Martin; Schmidt, Gert; Brachhold, Nora; Schöttler, Leandro; Rafaja, David; Aneziris, Christos G.

2018-06-01

Corrosion tests of carbon-free and carbon-containing refractories were performed. The carbon-free crucibles corroded, whereas the carbon-containing crucibles were negligibly attacked. On them, inclusions were attached. This study investigates melt oxygen contents, interface properties, and steel compositions with their non-metallic inclusions in order to explore the inclusion formation and deposition mechanisms. The carbon-free crucibles were based on alumina, mullite, and zirconia- and titania-doped alumina (AZT). The carbon-containing (-C) ones were alumina-C and AZT-C. Furthermore, nanoscaled carbon and alumina additives (-n) were applied in an AZT-C-n material. In the crucibles, the case-hardened steel 17CrNiMo7-6 was remelted at 1580 °C. It was observed that the melt and steel oxygen contents were higher for the tests in the carbon-free crucibles. Into these crucibles, the deoxidizing alloying elements Mn and Si diffused. Reducing contents of deoxidizing elements resulted in higher steel oxygen levels and less inclusions, mainly of the inclusion group SiO2-core-MnS-shell (2.5 to 8 μ m). These developed from smaller SiO2 nuclei. The inclusion amount in the steel was highest after remelting in AZT-C-n for 30 minutes but decreased strongly with increasing remelting time (60 minutes) due to inclusions' deposition on the refractory surface. The Ti from the AZT and the nanoadditives supported inclusion growth and deposition. Other inclusion groups were alumina and calcium aluminate inclusions. Their contents were high after remelting in carbon- or AZT-containing crucibles but generally decreased during remelting. On the AZT-C-n crucible, a dense layer formed from vitreous compositions including Al, Ca, Mg, Si, and Ti. To summarize, for reducing forming inclusion amounts, mullite is recommended as refractory material. For capturing formed inclusions, AZT-C-n showed a high potential.

Sub-micrometer refractory carbonaceous particles in the polar stratosphere

Science.gov (United States)

Schütze, Katharina; Wilson, James Charles; Weinbruch, Stephan; Benker, Nathalie; Ebert, Martin; Günther, Gebhard; Weigel, Ralf; Borrmann, Stephan

2017-10-01

Eleven particle samples collected in the polar stratosphere during SOLVE (SAGE III Ozone loss and validation experiment) from January until March 2000 were characterized in detail by high-resolution transmission and scanning electron microscopy (TEM/SEM) combined with energy-dispersive X-ray microanalysis. A total of 4202 particles (TEM = 3872; SEM = 330) were analyzed from these samples, which were collected mostly inside the polar vortex in the altitude range between 17.3 and 19.9 km. Particles that were volatile in the microscope beams contained ammonium sulfates and hydrogen sulfates and dominated the samples. Some particles with diameters ranging from 20 to 830 nm were refractory in the electron beams. Carbonaceous particles containing additional elements to C and O comprised from 72 to 100 % of the refractory particles. The rest were internal mixtures of these materials with sulfates. The median number mixing ratio of the refractory particles, expressed in units of particles per milligram of air, was 1.1 (mg air)-1 and varied between 0.65 and 2.3 (mg air)-1. Most of the refractory carbonaceous particles are completely amorphous, a few of the particles are partly ordered with a graphene sheet separation distance of 0.37 ± 0.06 nm (mean value ± standard deviation). Carbon and oxygen are the only detected major elements with an atomic O/C ratio of 0.11 ± 0.07. Minor elements observed include Si, S, Fe, Cr and Ni with the following atomic ratios relative to C: Si/C: 0.010 ± 0.011; S/C: 0.0007 ± 0.0015; Fe/C: 0.0052 ± 0.0074; Cr/C: 0.0012 ± 0.0017; Ni/C: 0.0006 ± 0.0011 (all mean values ± standard deviation).High-resolution element distribution images reveal that the minor elements are distributed within the carbonaceous matrix; i.e., heterogeneous inclusions are not observed. No difference in size, nanostructure and elemental composition was found between particles collected inside and outside the polar vortex. Based on chemistry and nanostructure

Oxygen isotopic anomalies in Allende inclusion HAL

International Nuclear Information System (INIS)

Lee, T.; Mayeda, T.K.; Clayton, R.N.

1980-01-01

The oxygen isotopic composition has been measured on the constituent phases of Allende inclusion HAL, which has unusual mineralogical, chemical, and calcium isotopic compositions. The oxygen in HAL is heterogeneous, with the rim showing more ''normal'' composition and the hibonite core showing large deviation from both the terrestrial material and the usual inclusions. The observed pattern indicates that HAL is a bona fide and more devious member of the rare ''FUN'' family, whose isotopic composition is characterized by correlated nuclear effects and extreme mass fractionation. The data imply that HAL has suffered a large oxygen mass fractionation of 25% 0 per mass unit, followed by exchange with oxygen in a second reservoir. The present experiment supports the identification of two distinct reservoirs from which all refractory inclusions in carbonaceous meteorites derived their oxygen. The required fractionation process seems to operate according to the volatility of various elements and could have been caused by evaporation during a heating event. Nuclear anomalies can be produced in the same heating event if the progenitors of the refractory inclusions were macroscopic aggregates of tiny pre-solar interstellar dust grains and if these grains were destroyed differentially during the evaporation

Inclusion-initiated fracture model for ceramics

International Nuclear Information System (INIS)

Sung, J.; Nicholson, P.S.

1990-01-01

The fracture of ceramics initiating from a typical inclusion is analyzed. The inclusion is considered to have a thermal expansion coefficient and fracture toughness lower than those of the matrix and a Young's modulus higher than that of the matrix. Inclusion-initiated fracture is modeled for a spherical inclusion using a weight function method to compute the residual stress intensity factor for a part-through elliptical crack. The results are applied to an α-Al 2 O 3 inclusion embedded in a tetragonal ZrO 2 ceramic. The strength predictions agree well with experimental data

Sub-micrometer refractory carbonaceous particles in the polar stratosphere

Directory of Open Access Journals (Sweden)

K. Schütze

2017-10-01

Full Text Available Eleven particle samples collected in the polar stratosphere during SOLVE (SAGE III Ozone loss and validation experiment from January until March 2000 were characterized in detail by high-resolution transmission and scanning electron microscopy (TEM/SEM combined with energy-dispersive X-ray microanalysis. A total of 4202 particles (TEM  =  3872; SEM  =  330 were analyzed from these samples, which were collected mostly inside the polar vortex in the altitude range between 17.3 and 19.9 km. Particles that were volatile in the microscope beams contained ammonium sulfates and hydrogen sulfates and dominated the samples. Some particles with diameters ranging from 20 to 830 nm were refractory in the electron beams. Carbonaceous particles containing additional elements to C and O comprised from 72 to 100 % of the refractory particles. The rest were internal mixtures of these materials with sulfates. The median number mixing ratio of the refractory particles, expressed in units of particles per milligram of air, was 1.1 (mg air−1 and varied between 0.65 and 2.3 (mg air−1. Most of the refractory carbonaceous particles are completely amorphous, a few of the particles are partly ordered with a graphene sheet separation distance of 0.37 ± 0.06 nm (mean value ± standard deviation. Carbon and oxygen are the only detected major elements with an atomic O∕C ratio of 0.11 ± 0.07. Minor elements observed include Si, S, Fe, Cr and Ni with the following atomic ratios relative to C: Si∕C: 0.010 ± 0.011; S∕C: 0.0007 ± 0.0015; Fe∕C: 0.0052 ± 0.0074; Cr∕C: 0.0012 ± 0.0017; Ni∕C: 0.0006 ± 0.0011 (all mean values ± standard deviation.High-resolution element distribution images reveal that the minor elements are distributed within the carbonaceous matrix; i.e., heterogeneous inclusions are not observed. No difference in size, nanostructure and elemental composition was found between

Chemical composition of HAL, an isotopically-unusual Allende inclusion

International Nuclear Information System (INIS)

Davis, A.M.; Tanaka, T.; Grossman, L.; Lee, T.; Wasserburg, G.J.

1982-01-01

Thirty-seven major, minor and trace elements were determined by INAA and RNAA in samples of hibonite, black rim and portions of friable rim from an unusual Allende inclusion, HAL. The peculiar isotopic, mineralogical and textural properties of HAL are accompanied by very unusual trace element abundances. The most striking feature of the chemistry is the virtual absence of Ce from an inclusion otherwise highly enriched in REE compared to C1 chondrites. HAL is also depleted in Sr, Ba, U, V, Ru, Os and Ir, relative to other refractory elements. Of the lithophile elements determined which are normally considered to be refractory in a gas of solar composition, Sr, Ba, Ce, U and V are the most volatile in oxidizing gases. The distribution of REE between hibonite and rims seems to have been established when hibonite and other refractory minerals were removed at slightly different temperatures from a hot, oxidizing gas in which they previously coexisted as separate grains. On the basis of HAL's chemical and isotopic composition, possible locations for the chemical and mass dependent isotopic fractionation are discussed. (author)

Refractory Research Group - U.S. DOE, Albany Research Center [Institution Profile

Energy Technology Data Exchange (ETDEWEB)

Bennett, James P.

2004-09-01

The refractory research group at the Albany Research Center (ARC) has a long history of conducting materials research within the U.S. Bureau of Mines, and more recently, within the U.S. Dept. of Energy. When under the U.S. Bureau of Mines, research was driven by national needs to develop substitute materials and to conserve raw materials. This mission was accomplished by improving refractory material properties and/or by recycling refractories using critical and strategic materials. Currently, as a U.S. Dept of Energy Fossil Energy field site, research is driven primarily by the need to assist DOE in meeting its vision to develop economically and environmentally viable technologies for the production of electricity from fossil fuels. Research at ARC impacts this vision by: • Providing information on the performance characteristics of materials being specified for the current generation of power systems; • Developing cost-effective, high performance materials for inclusion in the next generation of fossil power systems; and • Solving environmental emission and waste problems related to fossil energy systems. A brief history of past refractory research within the U.S. Bureau of Mines, the current refractory research at ARC, and the equipment and capabilities used to conduct refractory research at ARC will be discussed.

Use of hydroxypropyl-beta-cyclodextrin ad polymer matrix for formation of inclusion complex with drug nifedipine

International Nuclear Information System (INIS)

Carneiro, Elisa F.; Araujo, Marcia V.G. de; Barbosa, Ronilson V.; Silva, Caroline W.P. da; Barisson, Andersson; Zawadzki, Sonia F.; Andrade, George Ricardo S.; Costa Junior, Nivan B. da

2009-01-01

In this work it was prepared and characterized an inclusion complex between the polymeric matrix hydroxypropyl-beta cyclodextrin and nifedipine, a hydrophobic drug calcium antagonistic, used for the cardiovascular diseases treatment. The study of the phase- solubility diagram showed an increase of the aqueous solubility of the drug after inclusion, was observed and The differential scanning calorimetry analysis did not show the melting point temperature of the drug in the formed complex. This fact is considered as an evidence of the encapsulation process. 1 H NMR studies suggested that the non-aromatic ring of the nifedipine would be inserted in the cavity of the hydroxypropyl-beta-cyclodextrin.This orientation was also proposed by the used molecular modelling methods. (author)

Alkali metal-refractory metal biphase electrode for AMTEC

Science.gov (United States)

Williams, Roger M. (Inventor); Bankston, Clyde P. (Inventor); Cole, Terry (Inventor); Khanna, Satish K. (Inventor); Jeffries-Nakamura, Barbara (Inventor); Wheeler, Bob L. (Inventor)

1989-01-01

An electrode having increased output with slower degradation is formed of a film applied to a beta-alumina solid electrolyte (BASE). The film comprises a refractory first metal M.sup.1 such as a platinum group metal, suitably platinum or rhodium, capable of forming a liquid or a strong surface adsorption phase with sodium at the operating temperature of an alkali metal thermoelectric converter (AMTEC) and a second refractory metal insoluble in sodium or the NaM.sup.1 liquid phase such as a Group IVB, VB or VIB metal, suitably tungsten, molybdenum, tantalum or niobium. The liquid phase or surface film provides fast transport through the electrode while the insoluble refractory metal provides a structural matrix for the electrode during operation. A trilayer structure that is stable and not subject to deadhesion comprises a first, thin layer of tungsten, an intermediate co-deposited layer of tungsten-platinum and a thin surface layer of platinum.

Bacterial leaching as a pretreatment of refractory gold ores in sulphide matrix; La biolixiviacion como pretratamiento de menas auriferas refractarias en matriz de sulfuros

Energy Technology Data Exchange (ETDEWEB)

Iglesias, N.; Carranza, F.; Plaencia, I. [Universidad de Sevilla (Spain)

1998-06-01

In this paper the effectiveness of bacterial leaching as a pretreatment of gold ores bearing sulphide minerals is analysed. Three kinds of matrices are studied: pyrite, arsenopyrite and copper sulphides. It is concluded that bacterial leaching is an effective pretreatment for these refractory gold-bearing ores. In the case of a pyrite matrix a direct contact between the mineral and the microorganisms is necessary. In the case of copper or/and arsenic sulphide matrix, bacterial leaching may be carried out by indirect contact mechanism with effects separation, thus allowing faster kinetics than conventional bioleaching processes. This kinetics improvement reduces operation times and so the capital and operating costs. In a future, this fact may result in the enlargement of the profitable gold ore reserves, incorporating minerals that, at present, are not considered gold ores since there is not a technology, feasible from an economic point of view, for their treatment. (Author)

Refractory metal based superalloys

International Nuclear Information System (INIS)

Alonso, Paula R.; Vicente, Eduardo E.; Rubiolo, Gerardo H.

1999-01-01

Refractory metals are looked as promising materials for primary circuits in fission reactors and even as fusion reactor components. Indeed, superalloys could be developed which take advantage of their high temperature properties together with the benefits of a two- phase (intermetallic compound-refractory metal matrix) coherent structure. In 1993, researchers of the Office National d'Etudes et de Recherches Aerospatiales of France reported the observation of such a coherent structure in the Ta-Ti-Zr-Al-Nb-Mo system although the exact composition is not reported. The intermetallic compound would be Ti 2 AlMo based. However, the formation of this compound and its possible coexistence with a disordered bcc phase in the ternary system Ti-Al-Mo is a controversial subject in the related literature. In this work we develop a technique to obtain homogeneous alloys samples with 50 Ti-25 Al-25 Mo composition. The resulting specimens were characterized by optical and electronic metallography (SEM), microprobe composition measurements (EPMA) and X-ray diffraction (XRD) analyses. The results show the evidence for a bcc (A2→B2) ordering reaction in the Ti-Al-Mo system in the 50 Ti-25 Al-25 Mo composition. (author)

CALCULATION OF THE PROTON-TRANSFER RATE USING DENSITY-MATRIX EVOLUTION AND MOLECULAR-DYNAMICS SIMULATIONS - INCLUSION OF THE PROTON EXCITED-STATES

NARCIS (Netherlands)

MAVRI, J; BERENDSEN, HJC

1995-01-01

The methodology for treatment of proton transfer processes by density matrix evolution (DME) with inclusion of many excited states is presented. The DME method (Berendsen, H. J. C.; Mavri, J. J. Phys. Chem. 1993, 97, 13464) that simulates the dynamics of quantum systems embedded in a classical

A Review on Recent Advances on Magnesia-Doloma Refractories by Nano-Technology.

Directory of Open Access Journals (Sweden)

Salman Ghasemi-Kahrizsangi

2017-07-01

Full Text Available Due to exhibiting an excellent chemical resistance against basic environments at high temperature, good thermal shock resistance, thermodynamic stability in the presence of carbon, and a suitable abrasion resistance, MgO-CaO refractories are widely used in argon-oxygen decarburization furnaces in the metallurgy industry and cement rotary kilns. Furthermore, MgO-CaO refractories are beneficial to removing inclusions from molten steels; thus, they have been considered to be one of the effective refractory types for processing clean steel products. Also, MgO-CaO materials have become one of the attractive steelmaking refractories because of their low cost and high ore reserves.  However, in spite of these primary advantages, the application of MgO-CaO refractories has not been popular due to its tendency to hydration when exposed to the atmosphere.  In world most of MgO-CaO bricks producers used of organic components such as tar, pitch, and peck for produce MgO-CaO refractories. But during the application of these bricks in steel and cement and industrials, they released CO and CO2 gases to air and pollute the atmosphere. For this reason, recently some researcher investigate the effect of additive nanoparticles on MgO-CaO refractories performance. They reported the used of Nano-additive have acceptable results and additive nanoparticles can replace by aforementioned environment contaminating organic compounds. In this study, we reviewed all effort that done for improving the hydration resistance of MgO-CaO refractories by application of Nano-additives with an emphasis on the beneficial the use of additives nanoparticle for reduction of environmental pollution by various industries which used of MgO-CaO refractory bricks.

Slagging gasifier refractories. A new pathway to longer refractory life

Energy Technology Data Exchange (ETDEWEB)

Schnake, Mark [Harbinson-Walker Refractories Company, Mexico, MO (United States)

2013-07-01

Solid fuel slagging gasification to convert coal or petroleum coke feedstocks into syngas has rapidly evolved over the last 25 years. The gasifier is a high temperature, high pressure reaction chamber. Operating temperatures are between 1250 and 1575 C. Pressures will be between 20.4 and 68 atm. Syngas has been typically used for chemical feedstocks, fuel for power plants, or for steam and hydrogen generation in other industrial applications. Ash which comes from the solid fuel during gasification has many impurities. It melts during the gasifier reactor operation forming a liquid that penetrates the refractory lining. Given time, the refractory will wear away from thermal spalling, structural spalling, or overheating of the refractory. In some cases, all three wear mechanisms are seen in the same gasifier lining. Industry users have identified refractory life as one major limiting factor in worldwide use of this technology. Users have stated if the refractory liner can increase on-line availability of the gasifier operation, more industry acceptance of this technology is possible. Harbison-Walker Refractories Company will review destructive factors affecting lining life and discuss new refractory materials that have dramatically increased gasifier lining life and reliability. New refractory materials will be presented and supported by field trial results and post mortem analysis.

Performance of refractory alloy-clad fuel pins

International Nuclear Information System (INIS)

Dutt, D.S.; Cox, C.M.; Millhollen, M.K.

1984-12-01

This paper discusses objectives and basic design of two fuel-cladding tests being conducted in support of SP-100 technology development. Two of the current space nuclear power concepts use conventional pin type designs, where a coolant removes the heat from the core and transports it to an out-of-core energy conversion system. An extensive irradiation testing program was conducted in the 1950's and 1960's to develop fuel pins for space nuclear reactors. The program emphasized refractory metal clad uranium nitride (UN), uranium carbide (UC), uranium oxide (UO 2 ), and metal matrix fuels (UCZr and BeO-UO 2 ). Based on this earlier work, studies presented here show that UN and UO 2 fuels in conjunction with several refractory metal cladding materials demonstrated high potential for meeting space reactor requirements and that UC could serve as an alternative but higher risk fuel

Hydrogen embrittlement due to hydrogen-inclusion interactions

International Nuclear Information System (INIS)

Yu, H.Y.; Li, J.C.M.

1976-01-01

Plastic flow around inclusions creates elastic misfit which attracts hydrogen towards the regions of positive dilatation. Upon decohesion of the inclusion-matrix interface, the excess hydrogen escapes into the void and can produce sufficient pressure to cause void growth by plastic deformation. This mechanism of hydrogen embrittlement can be used to understand the increase of ductility with temperature, the decrease of ductility with hydrogen content, and the increase of ductility with the ultimate strength of the matrix. An examination of the effect of the shape of spheroid inclusion reveals that rods are more susceptible to hydrogen embrittlement than disks. The size of the inclusion is unimportant while the volume fraction of inclusions plays the usual role

High alumina refractories

International Nuclear Information System (INIS)

Simao, L.C.; Lopes, A.B.; Galvao Filho, N.B.; Souza, R.B. de

1989-01-01

High alumina refractories with 92 to 96.5% Al 2 O 3 were produced using brown and white fused as aggregate. Those refractories present only alumina-α and mullite as crystalline mineralogical phase. Other physical and chemical characteristics are similar to the ones found in refractories produced in Brazil, Japan and U.S.A. The most important physical and chemical tests used for the characterization of the raw materials and refractories, complemented by those realized at high temperatures, plus X-ray Difractometry and optical microscopy are presented, besides the refractory formulation and main parameters of production [pt

Development of a Refractory High Entropy Superalloy (Postprint)

Science.gov (United States)

2016-03-17

hardened with HfC precipitates [2], Co-Re- or Co-Al-W-based alloys [3] or two-phase ( FCC + L12) refractory superalloys based on platinum group metals...Ni-based superalloys consisting of cuboids with the ordered L12 structure embedded in an FCC solid-solution matrix. Based on this microstructural...and 5). A comparison of the average atomic radii with the measured lattice parameters allows us to conclude that the disordered BCC phase forming

Lead inclusions in aluminium

International Nuclear Information System (INIS)

Johnson, E.; Johansen, A.; Sarholt-Kristensen, L.; Andersen, H.H.; Grabaek, L.; Bohr, J.

1990-01-01

Ion implantation at room temperature of lead into aluminum leads to spontaneous phase separation and formation of lead precipitates growing topotactically with the matrix. Unlike the highly pressurized (∼ 1-5 GPa) solid inclusions formed after noble gas implantations, the pressure in the lead precipitates is found to be less than 0.12 GPa. Recently the authors have observed the result that the lead inclusions in aluminum exhibit both superheating and supercooling. In this paper they review and elaborate on these results. Small implantation-induced lead precipitates embedded in an aluminum matrix were studied by x-ray diffraction

Influence of the intermediate bcc phase on the evolution of superfluid inclusions in hcp matrix 3He-4He

International Nuclear Information System (INIS)

Birchenko, A.P.; Mikhin, N.P.; Neoneta, A.S.; Rudavskij, Eh.Ya.; Fisun, Ya.Yu.

2016-01-01

The evolution of liquid inclusions which are formed in the hcp matrix by rapid cooling of the 3 He- 4 He solution containing 1.05% 3 He was studied by pulse NMR. The diffusion coefficient of 3 He in the liquid was measured by two-pulses spin-echo method during evolution of the inclusions. Measurements were carried out at 1.67 K which corresponds to the bcc phase existence in the phase diagram, as well as at 1.38 K, where the bcc phase is absent. It is found that in the process of the evolution, in both cases the size of the liquid inclusions is less than diffusion length and so the diffusion is restricted. The measured restricted dif-fusion coefficient allowed to find the characteristic size of the inclusions. In the first case, during the evolution of liquid inclusions, dendrites of intermediate bcc phase is forming and the inclusions are separating into a lot of smaller droplets. Due to the rapid growth of the bcc dendrites, the droplet size decreases rapidly, and the process comes to disappearance of bcc phase and an amorphous state appearance. The results obtained by measuring the diffusion coefficient, correlated with the behavior of the spin-lattice relaxation time in such a system. In the second case at a lower temperature bcc phase is not formed, and the size of the liquid inclusions decreases very slow until the completion of their solidification.

Merits of using andalusite-based refractories compared to bauxite-based refractories

OpenAIRE

Nyoka, M.; Brazier, D.; Courtney, T.; Parry, R.A.

2013-01-01

Historically bauxite-based refractories have been used in applications where andalusite-based refractories could work. Bauxite-based refractories were chosen over andalusite-based refractories mainly because of the availability of low-cost Chinese bauxite and also because many furnaces were designed by international companies that cannot easily access high-quality products. Currently, the availability of low-cost bauxite is under threat as a result of high export duties and tariffs as well as...

Refractory Materials for Flame Deflector Protection System Corrosion Control: Refractory Ceramics Literature Survey

Science.gov (United States)

Calle, Luz Marina; Hintze, Paul E.; Parlier, Christopher R.; Curran, Jerome P.; Kolody, Mark; Perusich, Stephen; Whitten, Mary C.; Trejo, David; Zidek, Jason; Sampson, Jeffrey W.;

Refractory vasculitis

NARCIS (Netherlands)

Rutgers, Bram; Kallenberg, Cees G. M.

Refractory vasculitis occurs in 4-5% of patients with anti-neutrophil cytoplasmic antibody associated vasculitis (AAV). Differences between therapies used for refractory disease are mostly reflected in the percentages of complete and partial remissions, but also in the number of serious side

Pharmacotherapy for Refractory and Super-Refractory Status Epilepticus in Adults.

Science.gov (United States)

Holtkamp, Martin

2018-03-01

Patients with prolonged seizures that do not respond to intravenous benzodiazepines and a second-line anticonvulsant suffer from refractory status epilepticus and those with seizures that do not respond to continuous intravenous anesthetic anticonvulsants suffer from super-refractory status epilepticus. Both conditions are associated with significant morbidity and mortality. A strict pharmacological treatment regimen is urgently required, but the level of evidence for the available drugs is very low. Refractory complex focal status epilepticus generally does not require anesthetics, but all intravenous non-anesthetizing anticonvulsants may be used. Most descriptive data are available for levetiracetam, phenytoin and valproate. Refractory generalized convulsive status epilepticus is a life-threatening emergency, and long-term clinical consequences are eminent. Administration of intravenous anesthetics is mandatory, and drugs acting at the inhibitory gamma-aminobutyric acid (GABA) A receptor such as midazolam, propofol and thiopental/pentobarbital are recommended without preference for one of those. One in five patients with anesthetic treatment does not respond and has super-refractory status epilepticus. With sustained seizure activity, excitatory N-methyl-d-aspartate (NMDA) receptors are increasingly expressed post-synaptically. Ketamine is an antagonist at this receptor and may prove efficient in some patients at later stages. Neurosteroids such as allopregnanolone increase sensitivity at GABA A receptors; a Phase 1/2 trial demonstrated safety and tolerability, but randomized controlled data failed to demonstrate efficacy. Adjunct ketogenic diet may contribute to termination of difficult-to-treat status epilepticus. Randomized controlled trials are needed to increase evidence for treatment of refractory and super-refractory status epilepticus, but there are multiple obstacles for realization. Hitherto, prospective multicenter registries for pharmacological

Autoradiographic study of corrosion of refractories

International Nuclear Information System (INIS)

Lisenenkova, S.B.; Kucheryavyi, M.N.; Bursteva, T.A.

1988-01-01

A comparative study was made of the character of the interaction between a container-glass melt consisting of sodium calcium silicate and refractories in various furnace sections using an autoradiographic method. Static tests were conducted on specimens of the following refractories: chrome-aluminum-zircon, Bakor 41, corundum, a high alumina refractory, and a refractory based on tin dioxide. The specimens were activated by calcium 45. Autoradiography and photomicrography indicated that an intrinsic feature of all refractories was that calcium from the melt penetrated the refractories along the weak link; for fused-cast refractories, the glass phase; and for sintered refractories, through the binder and cracks

Melt quality induced failure of electrical conductor (EC grade aluminum wires

Directory of Open Access Journals (Sweden)

Khaliq A.

2017-01-01

Full Text Available The failure of electrical conductor grade (EC aluminum during wire drawing process was investigated. The fractured aluminum wires were subjected to Scanning Electron Microscopy (SEM and Energy Dispersive X-ray (EDX analyses for an initial examination. Thermodynamic analyses of molten aluminum interaction with refractories was also carried out using FactSage at 710°C to predict the stable phases. The SEM/EDX analyses has revealed the inclusions in aluminum matrix. The typical inclusions observed were Al2O3, Al3C4 (Al-Carbide and oxides of refractories elements (Al, Mg, Si and O that have particle size ranging up to 5 μm. The transition metal boride particles were not identified during SEM/EDX analyses these might be too fine to be detected with this microscope. The overall investigation suggested that the possible cause of this failure is second phase particles presence as inclusions in the aluminum matrix, and this was associated with the poor quality of melt. During wire drawing process, these inclusions were pulled out of the aluminum matrix by the wiredrawing forces to produce micro-voids which led to ductile tearing and final fracture of wires. It was recommended to use ceramic foam filters to segregate inclusions from molten aluminum.

Ar-39/Ar-40 systematics of Allende inclusions

International Nuclear Information System (INIS)

Herzog, G.F.; Rutgers University, New Brunswick, NJ); Bence, A.E.

1980-01-01

A laser microprobe was used to measure the Ar isotopic contents of individual mineral grains in four neutron-irradiated Allende samples: two coarse-grained Ca-Al-rich inclusions, one fine-grained Ca-Al-rich inclusion, and one sample with matrix and miscellaneous chondrules. The following K-Ar ages (G.y.) were obtained after degassing low Ar retentive sites by preheating the samples for one hour at 675 C: matrix, 3.5 + or - 0.2 three miscellaneous chondrules, 4.4 + or - 0.1, 4.0 + or - 0.1, and 4.4 + or - 0.1 and the fine-grained inclusion, 4.5 + or - 0.2. The minerals in the coarse-grained Ca-Al-rich inclusions have ubiquitous chlorine, less than 10 ppm K and apparent ages ranging upwards from 4.6 G.y. to well over 10 G.y. Possible explanations for these apparent ages are atmospheric contamination, the decay of K-40 prior to the formation of the solar system, and the trapping of radiogenic Ar-40 lost by the matrix

Effects of based Ca O and aluminum ash desulfurization agent on wearing of torpedo car refractories; Acao de agente dessulfurante a base de CaO + Al `ash`sobre o desgaste de refratario de carro torpedo

Energy Technology Data Exchange (ETDEWEB)

Silva, Sidiney Nascimento; Marques, Oscar Rosa; Delgado, Paulo Roberto Senna [Companhia Siderurgica Nacional, Volta Redonda, RJ (Brazil); Longo, Elson; Varela, Jose Arana [Sao Carlos Univ., SP (Brazil). Dept. de Quimica; Justus, Sergio Murilo [Universidade Estadual de Ponta Grossa, PR (Brazil). Dept. de Engenharia de Materiais

1996-12-31

The introduction oa a new desulfurization agent, at Companhia Siderurgica Nacional (CSN) based Ca O and aluminum ash, have been strongly altered the work conditions of slag line refractories of torpedo car. The wearing mechanism of Al{sub 2} O{sub 3}.Si C.C refractories of torpedo car slag line is as follows: graphite and silicon carbide oxidation by the gas present in torpedo car atmosphere and sodium oxide from process slag; as result from these oxidation reactions, there is a increasing of refractory permeability, simultaneously the silica precipitation in the refractory matrix; the refractory matrix, rich in mullite, strongly reacts with the calcium oxide from slag and silica excess, precipitated from oxidation reactions; as consequence, the formation of low melting point phases occurs which accelerates the wearing of material. (author) 12 refs., 6 figs., 8 tabs.

Emerging therapeutic options for sporadic inclusion body myositis

Directory of Open Access Journals (Sweden)

Alfano LN

2015-09-01

Full Text Available Lindsay N Alfano, Linda P Lowes Nationwide Children’s Hospital, Center for Gene Therapy, Columbus, OH, USA Abstract: Sporadic inclusion body myositis is the most common inflammatory muscle disorder preferentially affecting males over the age of 40 years. Progressive muscle weakness of the finger flexors and quadriceps muscles results in loss of independence with activities of daily living and eventual wheelchair dependence. Initial signs of disease are often overlooked and can lead to mis- or delayed diagnosis. The underlying cause of disease is unknown, and disease progression appears refractory to available treatment options. This review discusses the clinical presentation of inclusion body myositis and the current efforts in diagnosis, and focuses on the current state of research for both nonpharmacological and pharmacological treatment options for this patient group. Keywords: myositis, inclusion body myositis, inflammatory myopathy, treatment, function, outcomes

Effect of carbo-nitride-rich and oxide-rich inclusions on the pitting susceptibility of depleted uranium

International Nuclear Information System (INIS)

Pu, Zhen; Chen, Xianglin; Meng, Xiandong; Wu, Yanping; Shen, Liang; Wang, Qingfu; Liu, Tianwei; Shuai, Maobing

2017-01-01

Highlights: •The Volta potential differences relative to the matrix are positive for both types of inclusions. •Both types of inclusions are cathodic in the “inclusion/matrix” microgalvanic couples. •The oxide-rich inclusions show a larger Volta potential value of about 115 mV than the carbo-nitride-rich inclusions. •The oxide-rich inclusions give stronger local galvanic coupling with the matrix. •The oxide-rich inclusions are more predisposed to initiate pitting corrosion. -- Abstract: The effects of carbo-nitride-rich and oxide-rich inclusions on the pitting susceptibility of depleted uranium were investigated by electrochemical corrosion measurements, optical microscopy, scanning Kelvin probe force microscopy (SKPFM), and SEM. The results of the potentiodynamic polarization tests suggest that oxide-rich inclusions are more likely to induce pitting corrosion than carbo-nitride-rich inclusions. This enhanced corrosion may be explained by the strong local galvanic coupling between the oxide-rich inclusion and the surrounding matrix, which, from the sight of SKPFM analysis, exhibits a 115 V higher Volta potential than the coupling between the carbo-nitride-rich inclusions and the matrix, respectively.

Corrosion behavior of Al-Fe-sputtering-coated steel, high chromium steels, refractory metals and ceramics in high temperature Pb-Bi

International Nuclear Information System (INIS)

Abu Khalid, Rivai; Minoru, Takahashi

2007-01-01

Corrosion tests of Al-Fe-coated steel, high chromium steels, refractory metals and ceramics were carried out in high temperature Pb-Bi at 700 C degrees. Oxygen concentrations in this experiment were 6.8*10 -7 wt.% for Al-Fe-coated steels and 5*10 -6 wt.% for high chromium steels, refractory metals and ceramics. All specimens were immersed in molten Pb-Bi in a corrosion test pot for 1.000 hours. Coating was done with using the unbalanced magnetron sputtering (UBMS) technique to protect the steel from corrosion. Sputtering targets were Al and SUS-304. Al-Fe alloy was coated on STBA26 samples. The Al-Fe alloy-coated layer could be a good protection layer on the surface of steel. The whole of the Al-Fe-coated layer still remained on the base surface of specimen. No penetration of Pb-Bi into this layer and the matrix of the specimen. For high chromium steels i.e. SUS430 and Recloy10, the oxide layer formed in the early time could not prevent the penetration of Pb-Bi into the base of the steels. Refractory metals of tungsten (W) and molybdenum (Mo) had high corrosion resistance with no penetration of Pb-Bi into their matrix. Penetration of Pb-Bi into the matrix of niobium (Nb) was observed. Ceramic materials were SiC and Ti 3 SiC 2 . The ceramic materials of SiC and Ti 3 SiC 2 had high corrosion resistance with no penetration of Pb-Bi into their matrix. (authors)

Determination of the CKM-matrix element |Vub| from the electron energy spectrum measured in inclusive B→Xueν decay with the BABAR detector

International Nuclear Information System (INIS)

Lueck, Thomas

2013-01-01

This document presents a measurement of the CKM matrix-element vertical stroke V ub vertical stroke in inclusive semileptonic B→X u eν events on a dataset of 471 million B anti B events recorded by the BABAR detector. Inclusive B→X u eν decays are selected by reconstructing a high energetic electron (positron). Background suppression is achieved by selecting events with electron (positron) energies near the kinematical allowed endpoint of B→X u eν decays. A B→D * eν veto is applied to further suppress background. This veto uses D * mesons which have been reconstructed with a partial reconstruction technique.

Plasticity enhancement mechanisms in refractory metals and intermetallics

International Nuclear Information System (INIS)

Gibala, R.; Chang, H.; Czarnik, C.M.; Edwards, K.M.; Misra, A.

1993-01-01

Plasticity enhancement associated with surface films and precipitates or dispersoids in bcc refractory metals is operative in ordered intermetallic compounds. Some results are given for NiAl and MoSi 2 -based materials. The monotonic and cyclic plasticity of NiAl at room temperature can be enhanced by surface films. Ductile second phases also enhance the plasticity of NiAl. MoSi 2 exhibits similar effects of surface films and dispersoids, but primarily at elevated temperatures. The plasticity enhancement is associated with enhanced dislocation generation from constrained deformation at the film-substrate or precipitate/dispersoid-matrix interface of the composite systems

Bulk Vitrification Castable Refractory Block Protection Study

Energy Technology Data Exchange (ETDEWEB)

Hrma, Pavel R.; Bagaasen, Larry M.; Beck, Andrew E.; Brouns, Thomas M.; Caldwell, Dustin D.; Elliott, Michael L.; Matyas, Josef; Minister, Kevin BC; Schweiger, Michael J.; Strachan, Denis M.; Tinsley, Bronnie P.; Hollenberg, Glenn W.

2005-05-01

penetration of molten salt. Out of several refractory tile candidates, only greystone and fused-cast alumina-zirconia-silica (AZS) refractory remained intact and well bonded to the CRB after firing to 1000 C. The deformation of the refractory-tile composite was avoided by prefiring the greystone tile to 800 C. Condensed vapors did not penetrate the tiles, but Re salts condensed on their surface. Refractory corrosion tests indicated that a 0.25-inch-thick greystone tile would not corrode during a BV melt. Tiles can reduce both vapor penetration and molten salt penetration, but vapor deposition above the melt line will occur even on tiles. The Tc/Re transport scenario was outlined as follows. At temperatures below 700 C, molten ionic salt (MIS) that includes all the Tc/Re penetrates, by capillarity, from the feed into the CRB open porosity. At approximately 750 C, the MIS decomposes through the loss of NOx, leaving mainly sulfate and chloride salts. The Na2O formed in the decomposition of the nitrates reacts with insoluble grains in the feed and with the aluminosilicates in the CRB to form more viscous liquids that reduce further liquid penetration into the CRB. At 800 to 1000 C, a continuous glass phase traps the remains of the MIS in the form of inclusions in the bulk glass melt. At 1000 to 1200 C, the salt inclusions in the glass slowly dissolve but also rise to the surface. The Tc/Re salts also evaporate from the free surface of the glass melt that is rapidly renewed by convective currents. The vapors condense on cooler surfaces in the upper portion of the CRB, the box lid, and the off-gas system.

Biodegradable stents for the treatment of refractory or recurrent benign esophageal stenosis.

Science.gov (United States)

Imaz-Iglesia, Iñaki; García-Pérez, Sonia; Nachtnebel, Anna; Martín-Águeda, Belén; Sánchez-Piedra, Carlos; Karadayi, Bilgehan; Demirbaş, Ali Rıza

2016-06-01

Esophageal stents are used for the treatment of refractory and recurrent dyphagias. In 2007, esophageal biodegradable stents (EBS) were authorised as an alternative to existing metal and plastic stents in Europe. The advantages claimed for EBS are fewer complications concerning tissue ingrowth, stent migration and stent removal. We performed a systematic review to evaluate the efficacy and safety of EBS compared to fully-covered self-expanding metal stents, self-expanding plastic stents, and esophageal dilation for the treatment of refractory or recurrent benign esophageal stenosis. Three comparative studies (one randomized controlled trial and two cohort studies) were assessed. The studies used different inclusion criteria, had a very small (sample) size and the quality of the evidence was very low. Expert commentary: The current evidence is insufficient to determine the relative efficacy or safety of esophageal biodegradable stents. The results of this systematic review should be updated once new evidence is available.

Refractoriness in human atria

DEFF Research Database (Denmark)

Skibsbye, Lasse; Jespersen, Thomas; Christ, Torsten

2016-01-01

BACKGROUND: Refractoriness of cardiac cells limits maximum frequency of electrical activity and protects the heart from tonic contractions. Short refractory periods support major arrhythmogenic substrates and augmentation of refractoriness is therefore seen as a main mechanism of antiarrhythmic...... drugs. Cardiomyocyte excitability depends on availability of sodium channels, which involves both time- and voltage-dependent recovery from inactivation. This study therefore aims to characterise how sodium channel inactivation affects refractoriness in human atria. METHODS AND RESULTS: Steady......-state activation and inactivation parameters of sodium channels measured in vitro in isolated human atrial cardiomyocytes were used to parameterise a mathematical human atrial cell model. Action potential data were acquired from human atrial trabeculae of patients in either sinus rhythm or chronic atrial...

Intermediate coupling collision strengths from LS coupled R-matrix elements

International Nuclear Information System (INIS)

Clark, R.E.H.

1978-01-01

Fine structure collision strength for transitions between two groups of states in intermediate coupling and with inclusion of configuration mixing are obtained from LS coupled reactance matrix elements (R-matrix elements) and a set of mixing coefficients. The LS coupled R-matrix elements are transformed to pair coupling using Wigner 6-j coefficients. From these pair coupled R-matrix elements together with a set of mixing coefficients, R-matrix elements are obtained which include the intermediate coupling and configuration mixing effects. Finally, from the latter R-matrix elements, collision strengths for fine structure transitions are computed (with inclusion of both intermediate coupling and configuration mixing). (Auth.)

Plasma spraying of refractory metals and refractory hard materials. State of the art

International Nuclear Information System (INIS)

Eschnauer, H.; Lugscheider, E.; Jaeger, D.

1989-01-01

Suitable spraying processes for manufacturing refractory metals, refractory hard materials as well as spray materials with refractory components are the VPS- and IPS-spraying techniques. The advantages of these special spraying process variations are described. The reactive spraying materials are systematically organized. The characteristical properties used in purpose of improving the substrate surfaces are explained. Finally some examples of the latest results of research concerning plasma spraying of reactive materials are shown. 16 refs., 10 figs. (Author)

Study on fused/cast AZS refractories for deployment in vitrification of radioactive waste effluents

Science.gov (United States)

Sengupta, Pranesh; Mishra, R. K.; Soudamini, N.; Sen, D.; Mazumder, S.; Kaushik, C. P.; Ajithkumar, T. G.; Banerjee, K.

2015-12-01

'Fused/cast Al2O3-ZrO2-SiO2 (FC-AZS)' is being considered as 'glass contact refractory' within ceramic melters, to be used for nuclear waste immobilization. Microstructural analyses reveal random distributions of baddeleyite (ZrO2) within aluminosilicate (Al2SiO5) matrix. 27Al and 29Si NMR data suggest that within aluminosilicate matrix Al occurs in both 4- and 6-fold co-ordinations whereas Si prefers a 4-fold environment. Polydispersity of pores has been studied with small-angle neutron scattering (SANS) technique. Corrosion rates of FC-AZS within 6 M HNO3, simulated wastes (500 h exposure), and borosilicate melt (975 °C, 800 h exposure) are found to be 0.38 × 103 μmy-1, 0.13 × 103 μmy-1 and 4.75 × 103 μmy-1 respectively. A comparison of chemical interaction data clearly suggests that FC-AZS exhibits better chemical durability than AZC refractory (Al2O3-ZrO2-Cr2O3, also used for similar purpose). Thermal cycling studies indicate that FC-AZS retains structural integrity (including compressive strength and density) even up to 20 cycles.

Matrix transformation of Fibonacci band matrix on generalized $bv$-space and its dual spaces

Directory of Open Access Journals (Sweden)

Anupam Das

2018-07-01

Full Text Available In this paper we introduce a new sequence space $bv(\\hat{F}$ by using the Fibonacci band matrix $\\hat{F}.$ We also establish a few inclusion relations concerning this space and determine its $\\alpha-,\\beta-,\\gamma-$duals. Finally we characterize some matrix classes on the space $bv(\\hat{F}.$

Inclusions and mechanical behavior in the short transverse direction

International Nuclear Information System (INIS)

Aubert, H.; Bouleau, M.; Laniesse, J.; Lelong, C.; Pigoury, M.

1977-01-01

The variables liable to characterize the distribution of inclusions in plates, and the relationships between the mechanical properties and the fatigue behavior in, on the one hand, the short transverse direction, and, on the other hand, the inclusions are studied. A decoherence is shown between inclusions and matrix as the cause of the failure by lamellar tearing [fr

Theoretical and practical aspects about corrosion of refractories used in steel metallurgy: part 3: characterization of commercial refractories

International Nuclear Information System (INIS)

Braganca, S.R.

2012-01-01

In this study, it was reviewed the main aspects found in the literature about refractories corrosion, evaluating the feasibility of certain tests and relating them with experimental results. The physical properties and microstructure of commercial refractories were analyzed, considering the differences between them and the quality implications and probable life of the refractory. Thus, it was studied the various types of refractories used as lining on steel ladle. Magnesia-carbon and doloma-carbon refractories were analyzed, highlighting the differences between them. The examined refractory showed characteristics favoring high resistance to corrosion process, presenting a series of properties to be selected in accordance with industry practice. (author)

Cometary dust: the diversity of primitive refractory grains.

Science.gov (United States)

Wooden, D H; Ishii, H A; Zolensky, M E

2017-07-13

Comet dust is primitive and shows significant diversity. Our knowledge of the properties of primitive cometary particles has expanded significantly through microscale investigations of cosmic dust samples (anhydrous interplanetary dust particles (IDPs), chondritic porous (CP) IDPs and UltraCarbonaceous Antarctic micrometeorites, Stardust and Rosetta ), as well as through remote sensing ( Spitzer IR spectroscopy). Comet dust are aggregate particles of materials unequilibrated at submicrometre scales. We discuss the properties and processes experienced by primitive matter in comets. Primitive particles exhibit a diverse range of: structure and typology; distribution of constituents; concentration and form of carbonaceous and refractory organic matter; Mg- and Fe-contents of the silicate minerals; sulfides; existence/abundance of type II chondrule fragments; high-temperature calcium-aluminium inclusions and ameboid-olivine aggregates; and rarely occurring Mg-carbonates and magnetite, whose explanation requires aqueous alteration on parent bodies. The properties of refractory materials imply there were disc processes that resulted in different comets having particular selections of primitive materials. The diversity of primitive particles has implications for the diversity of materials in the protoplanetary disc present at the time and in the region where the comets formed.This article is part of the themed issue 'Cometary science after Rosetta'. © 2017 The Authors.

Alkaline sulfide pretreatment of an antimonial refractory Au-Ag ore for improved cyanidation

Science.gov (United States)

Alp, Ibrahim; Celep, Oktay; Deveci, Haci

2010-11-01

This paper presents the alkaline sulfide pretreatment of an antimonial refractory gold and silver ore. In the ore, gold occurs mainly as gold-silver alloys and as associated with quartz and framboidal pyrite grains, and, to a small extent, as the inclusions within antimonial sulfides. Silver is present extensively as antimonial sulfides such as andorite. Alkaline sulfide pretreatment was shown to allow the decomposition of the antimonial sulfide minerals (up to 98% Sb removal) and to remarkably improve the amenability of gold (e.g., from leaching. An increase in reagent concentration (1-4 mol/L Na2S or NaOH) and temperature (20-80°C), and a decrease in particle size seem to produce an enhancing effect on metal extraction. These findings suggest that alkaline sulfide leaching can be suitably used as a chemical pretreatment method prior to the conventional cyanidation for antimonial refractory gold and silver ores.

Effect of elevated temperatures on the mechanical behavior of basalt textile reinforced refractory concrete

International Nuclear Information System (INIS)

Rambo, Dimas Alan Strauss; Andrade Silva, Flávio de; Toledo Filho, Romildo Dias; Fonseca Martins Gomes, Otávio da

2015-01-01

Highlights: • The thermo-mechanical behavior of basalt TRC is investigated. • The fiber polymer coating can become a deterministic factor in the TRC response. • Pre-heating the TRC at 150 °C leads to a matrix–polymer interlocking mechanism. • Above 400 °C a sudden drop in the TRC tensile response is observed. - Abstract: The work in hand presents the results of an experimental investigation on the thermo-mechanical properties of a textile refractory composite reinforced with polymer coated basalt fibers under tensile loading. The composites were produced as a laminate material using basalt bi-directional fabric layers as reinforcement. A high alumina cement matrix was used in the matrix composition which was designed using the compressible packing method. A series of uniaxial tensile tests was performed under temperatures ranging from 25 to 1000 °C. The cracking mechanisms were discussed and compared to that obtained at room temperature. Thermogravimetry and X-ray diffraction analysis were used to study the deterioration/phase changes as a function of the studied temperatures. Scanning electron microscopy (SEM) was used to study the damage processes in the fiber–matrix interfaces after exposure to high temperatures. The obtained results indicated that the presence and the type of coating can become a deterministic factor in the tensile response of the composite submitted to elevated temperatures. A sudden drop in the serviceability limit state of the composite was observed above 400 °C, caused by the degradation of the polymer used as a fiber surface coating, the degradation of the basalt fiber and by the dehydration process of the refractory matrix

Corrosion of Metal Inclusions In Bulk Vitrification Waste Packages

Energy Technology Data Exchange (ETDEWEB)

Bacon, Diana H.; Pierce, Eric M.; Wellman, Dawn M.; Strachan, Denis M.; Josephson, Gary B.

2006-07-31

The primary purpose of the work reported here is to analyze the potential effect of the release of technetium (Tc) from metal inclusions in bulk vitrification waste packages once they are placed in the Integrated Disposal Facility (IDF). As part of the strategy for immobilizing waste from the underground tanks at Hanford, selected wastes will be immobilized using bulk vitrification. During analyses of the glass produced in engineering-scale tests, metal inclusions were found in the glass product. This report contains the results from experiments designed to quantify the corrosion rates of metal inclusions found in the glass product from AMEC Test ES-32B and simulations designed to compare the rate of Tc release from the metal inclusions to the release of Tc from glass produced with the bulk vitrification process. In the simulations, the Tc in the metal inclusions was assumed to be released congruently during metal corrosion as soluble TcO4-. The experimental results and modeling calculations show that the metal corrosion rate will, under all conceivable conditions at the IDF, be dominated by the presence of the passivating layer and corrosion products on the metal particles. As a result, the release of Tc from the metal particles at the surfaces of fractures in the glass releases at a rate similar to the Tc present as a soluble salt. The release of the remaining Tc in the metal is controlled by the dissolution of the glass matrix. To summarize, the release of 99Tc from the BV glass within precipitated Fe is directly proportional to the diameter of the Fe particles and to the amount of precipitated Fe. However, the main contribution to the Tc release from the iron particles is over the same time period as the release of the soluble Tc salt. For the base case used in this study (0.48 mass% of 0.5 mm diameter metal particles homogeneously distributed in the BV glass), the release of 99Tc from the metal is approximately the same as the release from 0.3 mass% soluble Tc

Magnesium and Titanium Isotopic Compositions of an Unusual Hibonite-Perovskite Refractory Inclusion from Allende: It Is Fun

Science.gov (United States)

Liu, M.-C.; Keller, L. P.; McKeegan, K. D.

2016-01-01

Introduction: Hibonite-rich refractory inclusions are among the first solids that formed in the solar nebula, and thus provide constraints on the earliest environment in the Solar System. An unusual hibonite-perovskite inclusion from Allende, SHAL, consists of a large (approximately 500 by 200 microns) single hibonite crystal and coexisting blocky perovskite (approximately 200 microns in size). The hibonite is characterized by chemical and oxygen isotopic compositions similar to those in the FUN (Fractionated and Unknown Nuclear anomalies) inclusion HAL. However, the rare earth element (REE) patterns measured at different spots of SHAL hibonite are highly variable, ranging from Group II-like (light REEs enriched relative to heavy REEs) to Group III-like (relatively flat with slight Eu depletions), but overall contrast largely with that of HAL, especially in the Ce and Yb abundances. This implies that SHAL hibonite formed and underwent distillation processes under more reducing conditions. Interestingly, the accompanying perovskite has uniform, unfractionated oxygen isotopic compositions (averaging delta (sup 17) O equals delta (sup 18) O equals -7 per mille) and REE abundances that are completely different from those of SHAL hibonite. This has been interpreted that perovskite and hibonite may not be co-genetic. Here we performed Al-Mg and Ti isotopic measurements of SHAL hibonite and perovskite to determine if the FUN characteristics are observed in these two isotope systems, and to further constrain the origin and evolution of SHAL. Results: Isotopic measurements of Al-Mg and Ti in SHAL were performed on the UCLA CAMECA ims-1290 ion microprobe by following the analytical protocols described in [1]. The Al-Mg and Ti data obtained in both terrestrial standards and SHAL hibonite and perovskite are shown below. Both SHAL hibonite and perovskite, despite very high (sup 27) Al to (sup 24) Mg ratios, are devoid of (sup 26) Mg excesses that can be attributed to the decay

A 20-year multicentre outcome analysis of salvage mechanical circulatory support for refractory cardiogenic shock after cardiac surgery

Directory of Open Access Journals (Sweden)

Maziar Khorsandi

2016-11-01

Full Text Available Abstract Background Refractory post-cardiotomy cardiogenic shock (PCCS is a relatively rare phenomenon that can lead to rapid multi-organ dysfunction syndrome and is almost invariably fatal without advanced mechanical circulatory support (AMCS, namely extra-corporeal membrane oxygenation (ECMO or ventricular assist devices (VAD. In this multicentre observational study we retrospectively analyzed the outcomes of salvage venoarterial ECMO (VA ECMO and VAD for refractory PCCS in the 3 adult cardiothoracic surgery centres in Scotland over a 20-year period. Methods The data was obtained through the Edinburgh, Glasgow and Aberdeen cardiac surgery databases. Our inclusion criteria included any adult patient from April 1995 to April 2015 who had received salvage VA ECMO or VAD for PCCS refractory to intra-aortic balloon pump (IABP and maximal inotropic support following adult cardiac surgery. Results A total of 27 patients met the inclusion criteria. Age range was 34–83 years (median 51 years. There was a large male predominance (n = 23, 85 %. Overall 23 patients (85 % received VA ECMO of which 14 (61 % had central ECMO and 9 (39 % had peripheral ECMO. Four patients (15 % were treated with short-term VAD (BiVAD = 1, RVAD = 1 and LVAD = 2. The most common procedure-related complication was major haemorrhage (n = 10. Renal failure requiring renal replacement therapy (n = 7, fatal stroke (n = 5, septic shock (n = 2, and a pseudo-aneurysm at the femoral artery cannulation site (n = 1 were also observed. Overall survival to hospital discharge was 40.7 %. All survivors were NYHA class I-II at 12 months’ follow-up. Conclusion AMCS for refractory PCCS carries a survival benefit and achieves acceptable functional recovery despite a significant complication rate.

Diffusion of nanosized sodium inclusions in platinum

International Nuclear Information System (INIS)

Poulsen, J.R.; Horsewell, A.; Eldrup, M.; Johnson, E.; Johansen, A.

1994-01-01

Na inclusions with diameters in the range from 2 nm to 15 nm have been made by ion implantation of Na into 70 nm thick single-crystalline Pt foils followed by annealing. The structure of solid inclusions and the diffusion of molten inclusions have been studied by transmission electron microscopy. At room temperature the inclusions are faceted and crystalline with a BCC structure and they are aligned topotactically with the Pt (FCC) matrix. The diffusion of inclusions in the liquid state was investigated by annealing at temperatures of 1227 K, 1432 K and 1534 K. The results are used to propose a method to produce sources for positron annihilation spectroscopy at high temperatures. (author)

Self-sensing and thermal energy experimental characterization of multifunctional cement-matrix composites with carbon nano-inclusions

Science.gov (United States)

D'Alessandro, A.; Pisello, A. L.; Sambuco, Sara; Ubertini, F.; Asdrubali, F.; Materazzi, A. L.; Cotana, F.

2016-04-01

The recent progress of Nanotechnology allowed the development of new smart materials in several fields of engineering. In particular, innovative construction materials with multifunctional enhanced properties can be produced. The paper presents an experimental characterization on cement-matrix pastes doped with Carbon Nanotubes, Carbon Nano-fibers, Carbon Black and Graphene Nano-platelets. Both electro-mechanical and thermo-physical investigations have been carried out. The conductive nano-inclusions provide the cementitious matrix with piezo-resistive properties allowing the detection of external strain and stress changes. Thereby, traditional building materials, such as concrete and cementitious materials in general, would be capable of self-monitoring the state of deformation they are subject to, giving rise to diffuse sensing systems of structural integrity. Besides supplying self-sensing abilities, carbon nano-fillers may change mechanical, physical and thermal properties of cementitious composites. The experimental tests of the research have been mainly concentrated on the thermal conductivity and the optical properties of the different nano-modified materials, in order to make a critical comparison between them. The aim of the work is the characterization of an innovative multifunctional composite capable of combining self-monitoring properties with proper mechanical and thermal-energy efficiency characteristics. The potential applications of these nano-modified materials cover a wide range of possibilities, such as structural elements, floors, geothermal piles, radiant systems and more.

Evaluation of the reusing of MGO-C refractory brick in refractory mixes

International Nuclear Information System (INIS)

Silva, R.D.S. da; Braganca, S.R.

2012-01-01

The residue from the use of MgO-C refractories in electric arc furnace presents, mostly, magnesium oxide in its composition and some slag contamination and impurities from the process of electrofusion scrap iron/steel. In this study, it was studied the characteristics of this residue and reused through its introduction into a commercial refractory mix, employed as material of coating and repair. This refractory mix was tested by thermogravimetric analysis, compressive strength, evaluation of plasticity and porosity as well as aspects of its installation, such as adhesion in situ. Results showed that there potential for reuse with the introduction of the waste in commercial mix was 30%, with little loss of compressive strength and plasticity. (author)

Improved high temperature refractory. [MgCr/sub 2/O/sub 4/ composite with ZrO/sub 2/

Science.gov (United States)

Singh, J.P.; James, J.; Picciolo, J.J.

1985-12-10

A high chromia refractory composite has been developed with improved thermal shock resistance and containing about 5 to 30 wt % of unstabilized ZrO/sub 2/ having a temperature-dependent phase change resulting in large expansion mismatch between the ZrO/sub 2/ and the chromia matrix which causes microcracks to form during cooling in the high chromia matrix. The particle size preferably is primarily between about 0.6 to 5 microns and particularly below about 3 microns with an average size in the order of 1.2 to 1.8 microns.

Sorafenib in radioactive iodine-refractory, locally advanced or metastatic differentiated thyroid cancer

DEFF Research Database (Denmark)

Brose, Marcia S; Nutting, Christopher M; Jarzab, Barbara

2014-01-01

cancer that had progressed within the past 14 months. Adult patients (≥18 years of age) with this type of cancer were enrolled from 77 centres in 18 countries. To be eligible for inclusion, participants had to have at least one measurable lesion by CT or MRI according to Response Evaluation Criteria...... cancer. Adverse events were consistent with the known safety profile of sorafenib. These results suggest that sorafenib is a new treatment option for patients with progressive radioactive iodine-refractory differentiated thyroid cancer. FUNDING: Bayer HealthCare Pharmaceuticals and Onyx Pharmaceuticals...

Study on fused/cast AZS refractories for deployment in vitrification of radioactive waste effluents

Energy Technology Data Exchange (ETDEWEB)

Sengupta, Pranesh, E-mail: praneshsengupta@gmail.com [Materials Science Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Mishra, R.K.; Soudamini, N. [Waste Management Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Sen, D.; Mazumder, S. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Kaushik, C.P. [Waste Management Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Ajithkumar, T.G. [Central NMR Facility, National Chemical Laboratory, Pune 411 008 (India); Banerjee, K. [Nuclear Recycle Group, Mumbai 400 085 (India)

2015-12-15

‘Fused/cast Al{sub 2}O{sub 3}–ZrO{sub 2}–SiO{sub 2} (FC-AZS)’ is being considered as ‘glass contact refractory’ within ceramic melters, to be used for nuclear waste immobilization. Microstructural analyses reveal random distributions of baddeleyite (ZrO{sub 2}) within aluminosilicate (Al{sub 2}SiO{sub 5}) matrix. {sup 27}Al and {sup 29}Si NMR data suggest that within aluminosilicate matrix Al occurs in both 4- and 6-fold co-ordinations whereas Si prefers a 4-fold environment. Polydispersity of pores has been studied with small-angle neutron scattering (SANS) technique. Corrosion rates of FC-AZS within 6 M HNO{sub 3}, simulated wastes (500 h exposure), and borosilicate melt (975 °C, 800 h exposure) are found to be 0.38 × 10{sup 3} μmy{sup −1}, 0.13 × 10{sup 3} μmy{sup −1} and 4.75 × 10{sup 3} μmy{sup −1} respectively. A comparison of chemical interaction data clearly suggests that FC-AZS exhibits better chemical durability than AZC refractory (Al{sub 2}O{sub 3}–ZrO{sub 2}–Cr{sub 2}O{sub 3}, also used for similar purpose). Thermal cycling studies indicate that FC-AZS retains structural integrity (including compressive strength and density) even up to 20 cycles. - Highlights: • Vitrification of nuclear waste using AZS refractory within ceramic melter. • Microstructure of AZS refractory. • Interaction of AZS with simulated high level waste and glass.

A one-year prospective study of refractory status epilepticus in Modena, Italy.

Science.gov (United States)

Giovannini, Giada; Monti, Giulia; Polisi, Michela M; Mirandola, Laura; Marudi, Andrea; Pinelli, Giovanni; Valzania, Franco; Girardis, Massimo; Nichelli, Paolo F; Meletti, Stefano

2015-08-01

Refractory status epilepticus (RSE) is a particular critical condition characterized by seizures that continue despite the use of first- and second-line therapies and by high mortality. To date, only one prospective study investigated clinical features and prognostic factors in RSE. In this study, we performed a one-year prospective survey to identify clinical features, outcomes, and variables associated with the development of RSE in the adolescent and adult population of Modena, northern Italy. We observed 83 episodes of SE in 83 patients. In 31% of the cases, third-line therapy (anesthetic drug) was needed. Among this group, 14% resolved and were classified as RSE, while, in 17%, seizures recurred at withdrawal of anesthetics and were classified as super-RSE. The development of RSE/super-RSE was associated with a stuporous/comatose state at presentation and with the absence of a previous history of epilepsy. Refractory status epilepticus/super-refractory status epilepticus showed a worse outcome compared with responsive SE: 54% versus 21% for 30-day mortality; 19% versus 56% for a return to baseline condition. This prospective study confirms stupor/coma at onset as a relevant clinical factor associated with SE refractoriness. We observed a rate of RSE comparable with previous reports, with high mortality and morbidity. Mortality in the observed RSE was higher than in previous studies; this result is probably related to the low rate of a previous epilepsy history in our population that reflects a high incidence of acute symptomatic etiologies, especially the inclusion of patients with postanoxic SE who have a bad prognosis per se. This article is part of a Special Issue entitled "Status Epilepticus". Copyright © 2015 Elsevier Inc. All rights reserved.

Characterization of a Fe inclusion in beryllium-matrix using auger electron spectroscopy

International Nuclear Information System (INIS)

Arkusk, R.; Moreno, D.; Simca, F.; Yeheskel, O.; Utzmoni, U.

1991-04-01

The auger electron spectroscopy techniques was employed to investigate the nature of an inclusion that had been revealed by radiography in a beryllium body produced by the hot isostatic press technique. The investigation's are that the inclusion is composed of several different iron-beryllium intermetallic compounds (BeFe 3 , BeFe 5 , Be 7 Fe). The conclusion drawn is that iron metal impurity was imbedded in the Be powder and that interdiffusion under the process's conditions gave rise to the enlarged inclusion. (author)

Effect of main inclusions on crack initiation in bearing steel in the very high cycle fatigue regime

Science.gov (United States)

Gu, Chao; Bao, Yan-ping; Gan, Peng; Wang, Min; He, Jin-shan

2018-06-01

This work aims to investigate the effect of main inclusions on crack initiation in bearing steel in the very high cycle fatigue (VHCF) regime. The size and type of inclusions in the steel were quantitatively analyzed, and VHCF tests were performed. Some fatigue cracks were found to be initiated in the gaps between inclusions (Al2O3, MgO-Al2O3) and the matrix, while other cracks originated from the interior of inclusions (TiN, MnS). To explain the related mechanism, the tessellated stresses between inclusions and the matrix were calculated and compared with the yield stress of the matrix. Results revealed that the inclusions could be classified into two types under VHCF; of these two, only one type could be regarded as holes. Findings in this research provide a better understanding of how inclusions affect the high cycle fatigue properties of bearing steel.

Compatibility of refractory materials with boiling sodium

International Nuclear Information System (INIS)

Meacham, S.A.

1976-01-01

The program employed to determine the compatibility of commercially available refractories with boiling sodium is described. The effects of impurities contained within the refractory material, and their relations with the refractory's physical stability are discussed. Also, since consideration of refractories for use as an insulating material within Liquid Metal Fast Breeder Reactor Plants (LMFBR's) is currently under investigation; recommendations, based upon this program, are presented

REFRACTORY THROMBOCYTOPENIA AND NEUTROPENIA: A DIAGNOSTIC CHALLENGE

OpenAIRE

Emmanuel Gyan; François Dreyfus; Pierre Fenaux

2015-01-01

Background. The 2008 WHO classification identified refractory cytopenia with unilineage dysplasia (RCUD) as a composite entity encompassing refractory anemia, refractory thrombocytopenia (RT), and refractory neutropenia (RN), characterized by 10% or more dysplastic cells in the bone marrow respective lineage. The diagnosis of RT and RN is complicated by several factors.  Diagnosing RT first requires exclusion of familial thrombocytopenia, chronic auto-immune thrombocytopenia, concomitant medi...

Mathematical Modeling of Electrical Conductivity of Dielectric with Dispersed Metallic Inclusions

Directory of Open Access Journals (Sweden)

V. S. Zarubin

2015-01-01

Full Text Available Composites are increasingly used for application in engineering as structural, thermal protection and functional materials, including dielectrics, because of a wide variety of properties. The relative dielectric constant and the dielectric loss tangent are basic functional characteristics of a composite used as a dielectric. The quantitative level of these characteristics is mainly affected by the properties of the composite matrix and inclusions as well as their shape and volume concentration. Metallic inclusions in a dielectric, which serves as a function of the composite matrix, expand electrical properties of the composite in particular increase its dielectric constant and dielectric loss tangent and thereby greatly expand its application field. Dielectric losses are defined by the imaginary component of the complex value of the relative dielectric constant of the dielectric. At a relatively low vibration frequency of electromagnetic field affecting the dielectric, this value is proportional to the electrical conductivity of the dielectric and inversely proportional to the frequency. In order to predict the expected value of the electric conductivity of the dielectric with metallic inclusions, a mathematical model that properly describes the structure of the composite and the electrical interaction of the matrix and inclusions is required.In the paper, a mathematical model of the electrical interaction of the representative element of the composite structure and a homogeneous isotropic medium with electrical conductivity, which is desired characteristics of the composite, is constructed. Globular shape of the metallic inclusions as an average statistical form of dispersed inclusions with a comparable size in all directions is adopted. The inclusion is covered with a globular layer of electrical insulation to avoid percolation with increasing volume concentration of inclusions. Outer globular layer of representative structure of composite

Mg isotope evidence for contemporaneous formation of chondrules and refractory inclusions

DEFF Research Database (Denmark)

Bizzarro, Martin; Baker, J.A.; Haack, Henning

2004-01-01

Primitive or undifferentiated meteorites (chondrites) date back to the origin of the Solar System, and thus preserve a record of the physical and chemical processes that occurred during the earliest evolution of the accretion disk surrounding the young Sun. The oldest Solar System materials present...... within these meteorites are millimetre- to centimetre-sized calcium-aluminium-rich inclusions (CAIs) and ferromagnesian silicate spherules (chondrules), which probably originated by thermal processing of pre-existing nebula solids. Chondrules are currently believed to have formed ~2-3 million years (Myr...

Refractory bin for burning

Energy Technology Data Exchange (ETDEWEB)

McPherson, D.L.; McPherson, T.L.

1989-12-26

This patent describes a refractory bin. It has a generally rectangular horizontal cross sectional configuration. It has wall structures each comprising an upper and a lower pair of elongated horizontal vertically spaced generally parallel support beams each having a vertical flange defining a support edge along its upper surface, a first generally rectangular refractory panel arranged with its lower edge at the bottom of the bin and with its outer surface in flat face contacting relation with the vertical flanges of the lower pair of support beams, a plurality of brackets each having a horizontal part and a vertical part and being secured to the outer surface of the first refractory panel.

Chemical composition of HAL, an isotopically-unusual Allende inclusion

Science.gov (United States)

Davis, A. M.; Tanaka, T.; Grossman, L.; Lee, T.; Wasserburg, G. J.

1982-01-01

Samples of hibonite, black rim, and portions of friable rim from an unusual Allende inclusion, named HAL, were analyzed by INAA and RNAA for 37 major, minor, and trace elements. An unusually low amount of Ce was found in HAL, although it otherwise was highly enriched in REE compared to C1 chondrites. HAL is also depleted in Sr, Ba, U, V, Ru, Os, and Ir relative to other refractory elements. It is concluded that the distribution of REE between hibonite and rims was established when hibonite and other refractory minerals were removed at slightly different temperatures from a hot, oxidizing gas in which they previously coexisted as separate grains. Possible locations for the chemical and mass dependent isotopic fractionation are considered to be in ejecta from the low temperature helium-burning zone of a supernova and in the locally oxidizing environment generated by evaporation of interstellar grains of near-chondritic chemical composition.

Talimogene Laherparepvec and Nivolumab in Treating Patients With Refractory Lymphomas or Advanced or Refractory Non-melanoma Skin Cancers

Science.gov (United States)

2018-05-21

Adenoid Cystic Carcinoma; Adnexal Carcinoma; Apocrine Carcinoma; Eccrine Porocarcinoma; Extraocular Cutaneous Sebaceous Carcinoma; Hidradenocarcinoma; Keratoacanthoma; Malignant Sweat Gland Neoplasm; Merkel Cell Carcinoma; Microcystic Adnexal Carcinoma; NK-Cell Lymphoma, Unclassifiable; Non-Melanomatous Lesion; Paget Disease; Papillary Adenocarcinoma; Primary Cutaneous Mucinous Carcinoma; Refractory Anaplastic Large Cell Lymphoma; Refractory Mature T-Cell and NK-Cell Non-Hodgkin Lymphoma; Refractory Mycosis Fungoides; Refractory Primary Cutaneous T-Cell Non-Hodgkin Lymphoma; Refractory T-Cell Non-Hodgkin Lymphoma; Sezary Syndrome; Signet Ring Cell Carcinoma; Skin Basal Cell Carcinoma; Skin Basosquamous Cell Carcinoma; Skin Squamous Cell Carcinoma; Spiradenocarcinoma; Squamous Cell Carcinoma of Unknown Primary Origin; Stage III Skin Cancer; Stage IV Skin Cancer; Sweat Gland Carcinoma; Trichilemmocarcinoma; Vulvar Squamous Cell Carcinoma

Stiffening solids with liquid inclusions

Science.gov (United States)

Style, Robert W.; Boltyanskiy, Rostislav; Allen, Benjamin; Jensen, Katharine E.; Foote, Henry P.; Wettlaufer, John S.; Dufresne, Eric R.

2015-01-01

From bone and wood to concrete and carbon fibre, composites are ubiquitous natural and synthetic materials. Eshelby’s inclusion theory describes how macroscopic stress fields couple to isolated microscopic inclusions, allowing prediction of a composite’s bulk mechanical properties from a knowledge of its microstructure. It has been extended to describe a wide variety of phenomena from solid fracture to cell adhesion. Here, we show experimentally and theoretically that Eshelby’s theory breaks down for small liquid inclusions in a soft solid. In this limit, an isolated droplet’s deformation is strongly size-dependent, with the smallest droplets mimicking the behaviour of solid inclusions. Furthermore, in opposition to the predictions of conventional composite theory, we find that finite concentrations of small liquid inclusions enhance the stiffness of soft solids. A straightforward extension of Eshelby’s theory, accounting for the surface tension of the solid-liquid interface, explains our experimental observations. The counterintuitive stiffening of solids by fluid inclusions is expected whenever inclusion radii are smaller than an elastocapillary length, given by the ratio of the surface tension to Young’s modulus of the solid matrix. These results suggest that surface tension can be a simple and effective mechanism to cloak the far-field elastic signature of inclusions.

Dissolution of nonmetallic inclusions at high-temperature heating

International Nuclear Information System (INIS)

Gubenko, S.I.

1983-01-01

The effect of high-temperature a nnealing on size, distribution and general content of non-metallic inclusions in steels is investigated. It is shown that high-temperature annealing of steel permits to reduce total amount of inclusions, their average size, as well as to control their composition and distribution in steel matrix. Partial or complete dissolution of inclusions takes place in respect to the type of non-metallic inclusions, temperature of annealing and holding duration. Cooling rate affects the investigated parameters. Under quenching the total amount of inclusions in steel is lower and average size of inclusions is larger than those under slow cooling. It is explained by precipitation of disperses ''satellites around the initial inclusions under low cooling. Composition of the satellites slightly differs from that of a ''mother's'' one. Change in composition of inclusions and creation of conditions for transition of unstable inclusions to a more stable state promotes change in properties of non-metallic inclusions that affects steel properties

Metallic-fibre-reinforced ceramic-matrix composite

International Nuclear Information System (INIS)

Prevost, F.; Schnedecker, G.; Boncoeur, M.

1994-01-01

A refractory metal wire cloth is embedded in an oxide ceramic matrix, using a plasma spraying technology, in order to elaborate composite plates. When mechanically tested, the composite fails with a pseudo-ductile fracture mode whereas the ceramic alone is originally brittle. It exhibits a higher fracture strength, and remains in the form of a single piece even when straining is important. No further heat treatment is needed after the original processing to reach these characteristics. (authors). 2 figs., 2 refs

Scattering of elastic waves by thin inclusions

International Nuclear Information System (INIS)

Simons, D.A.

1980-01-01

A solution is derived for the elastic waves scattered by a thin inclusion. The solution is asymptotically valid as inclusion thickness tends to zero with the other dimensions and the frequency fixed. The method entails first approximating the total field in the inclusion in terms of the incident wave by enforcing the appropriate continuity conditions on traction and displacement across the interface, then using these displacements and strains in the volume integral that gives the scattered field. Expressions are derived for the far-field angular distributions of P and S waves due to an incident plane P wave, and plots are given for normalized differential cross sections of an oblate spheroidal tungsten carbide inclusion in a titanium matrix

Application of x-ray fluorescence (XRF) absolute analysis method for silica refractories

International Nuclear Information System (INIS)

Asakura, Hideo; Yamada, Yasujiro; Kansai, Kouhei; Tomatsu, Ichirou; Murata, Mamoru

2015-01-01

X-ray fluorescence (XRF) analysis is a rapid and precise quantitative analytical method for the determination of major and trace elements in many industries and academics. XRF analytical values are relative due to the use of the calibration curves calculated from measuring the reference standard materials such as Japanese Refractory Reference Materials (JRRM) series with certified values determined by wet chemical analysis. The development of the XRF analytical method from relative to absolute analysis will help much to determine the absolute values of samples from the fields where reference standard samples have not been prepared, and thus can be applied widely in many industries. The implement of the absolute XRF analysis for silica refractories requires high purity reagents and/or reference standard solution for the binary basic calibration curve, and theoretical matrix correction coefficients for the multi-components silica refractories analysis. The reproducibility and repeatability of this method for Al 2 O 3 5 mass% sample were 0.009 and 0.006 mass% in Al 2 O 3 and showed better values that those of ICP-AES recognized as an absolute method in JIS R 2212-2, which yielded 0.028 and 0.031 mass%, respectively. The XRF absolute analysis for JRRM 200 series, 201a and 205a does not show a bias but coincides with their certified values. (author)

Emergency Surgery for Refractory Status Epilepticus.

Science.gov (United States)

Botre, Abhijeet; Udani, Vrajesh; Desai, Neelu; Jagadish, Spoorthy; Sankhe, Milind

2017-08-15

Management of refractory status epilepticus in children is extremely challenging. Two children with medically refractory status epilepticus, both of whom had lesional pathology on MRI and concordant data on EEG and PET scan. Emergency hemispherotomy performed in both patients. A complete, sustained seizure freedom obtained postoperatively. Emergency surgery is a treatment option in selected cases of drug refractory status epilepticus with lesional pathology and concordant data.

Phase diagrams of ferroelectric nanocrystals strained by an elastic matrix

Science.gov (United States)

Nikitchenko, A. I.; Azovtsev, A. V.; Pertsev, N. A.

2018-01-01

Ferroelectric crystallites embedded into a dielectric matrix experience temperature-dependent elastic strains caused by differences in the thermal expansion of the crystallites and the matrix. Owing to the electrostriction, these lattice strains may affect polarization states of ferroelectric inclusions significantly, making them different from those of a stress-free bulk crystal. Here, using a nonlinear thermodynamic theory, we study the mechanical effect of elastic matrix on the phase states of embedded single-domain ferroelectric nanocrystals. Their equilibrium polarization states are determined by minimizing a special thermodynamic potential that describes the energetics of an ellipsoidal ferroelectric inclusion surrounded by a linear elastic medium. To demonstrate the stability ranges of such states for a given material combination, we construct a phase diagram, where the inclusion’s shape anisotropy and temperature are used as two parameters. The ‘shape-temperature’ phase diagrams are calculated numerically for PbTiO3 and BaTiO3 nanocrystals embedded into representative dielectric matrices generating tensile (silica glass) or compressive (potassium silicate glass) thermal stresses inside ferroelectric inclusions. The developed phase maps demonstrate that the joint effect of thermal stresses and matrix-induced elastic clamping of ferroelectric inclusions gives rise to several important features in the polarization behavior of PbTiO3 and BaTiO3 nanocrystals. In particular, the Curie temperature displays a nonmonotonic variation with the ellipsoid’s aspect ratio, being minimal for spherical inclusions. Furthermore, the diagrams show that the polarization orientation with respect to the ellipsoid’s symmetry axis is controlled by the shape anisotropy and the sign of thermal stresses. Under certain conditions, the mechanical inclusion-matrix interaction qualitatively alters the evolution of ferroelectric states on cooling, inducing a structural transition

Updates in Refractory Status Epilepticus

Science.gov (United States)

Mahulikar, Advait; Suchdev, Kushak; Shah, Aashit

2018-01-01

Refractory status epilepticus is defined as persistent seizures despite appropriate use of two intravenous medications, one of which is a benzodiazepine. It can be seen in up to 40% of cases of status epilepticus with an acute symptomatic etiology as the most likely cause. New-onset refractory status epilepticus (NORSE) is a recently coined term for refractory status epilepticus where no apparent cause is found after initial testing. A large proportion of NORSE cases are eventually found to have an autoimmune etiology needing immunomodulatory treatment. Management of refractory status epilepticus involves treatment of an underlying etiology in addition to intravenous anesthetics and antiepileptic drugs. Alternative treatment options including diet therapies, electroconvulsive therapy, and surgical resection in case of a focal lesion should be considered. Short-term and long-term outcomes tend to be poor with significant morbidity and mortality with only one-third of patients reaching baseline neurological status. PMID:29854452

Tungsten isotopes in bulk meteorites and their inclusions-Implications for processing of presolar components in the solar protoplanetary disk

DEFF Research Database (Denmark)

Holst, Jesper Christian; Paton, Chad; Wielandt, Daniel Kim Peel

2015-01-01

We present high precision, low- and high-resolution tungsten isotope measurements of iron meteorites Cape York (IIIAB), Rhine Villa (IIIE), Bendego (IC), and the IVB iron meteorites Tlacotepec, Skookum, and Weaver Mountains, as well as CI chondrite Ivuna, a CV3 chondrite refractory inclusion (CAI...

Tracers application method for the quantitative determination of the source of oxygenic inclusions in steel

International Nuclear Information System (INIS)

Rewienska-Kosciukowa, B.; Dalecki, W.; Michalik, J.S.

1976-01-01

The sense and the possibility of radioactive and nonradioactive isotopic tracers application in investigations of the origin of oxygenic nonmetalic inclusions is presented. The discussed methods touch the investigations such as the origin of egzogenic inclusions which passed from external sources (fireproof lining, slag) to the steel or as the endogenic ones formed during the process of steel deoxidisation. The question of the tracers choice for refractory material and the further investigations concerned the determination of the origin of nonmetallic inclusions are discussed. The question of so called isotopic replacement tracers for the main steel deoxidizing agents is considered. The criterion of determination of oxygenic inclusions formed during the process of steel deoxidization is also discussed. Several results of laboratory and industrial investigations and also the examples of application of the discussed methods in the industrial scale are presented. (author)

Use of radioactive indicators for the quantitative determination of non-metall inclusions in steel

International Nuclear Information System (INIS)

Rewienska-Kosciuk, B.; Michalik, J.

1979-01-01

Methods of determining and investigating the sources of non-metal inclusions in steel are presented together with some results of radiometric investigations. The experience of several years of research in industries as well as profound studies of world literature were used as a basis for systematic and critical discussion of the methods used. Optimum methods have been chosen for the quantitative determination of oxide inclusions and for the identification of their origin (e.g. from the refractory furnace lining, the tap-hole, the runner, the ladle or mold slag). Problems of tracers (type, quantity, condition, activity), of the labelling method suitable for the various origins of inclusions, of sampling, of chemical processing of the material sampled, as well as of radiometric measuring techniques (including possible activation) are discussed. Finally, a method for the determination of inclusions resulting from the deoxidation of steel is briefly outlined. (author)

Refractory status epilepticus

Directory of Open Access Journals (Sweden)

Sanjay P Singh

2014-01-01

Full Text Available Refractory status epilepticus is a potentially life-threatening medical emergency. It requires early diagnosis and treatment. There is a lack of consensus upon its semantic definition of whether it is status epilepticus that continues despite treatment with benzodiazepine and one antiepileptic medication (AED, i.e., Lorazepam + phenytoin. Others regard refractory status epilepticus as failure of benzodiazepine and 2 antiepileptic medications, i.e., Lorazepam + phenytoin + phenobarb. Up to 30% patients in SE fail to respond to two antiepileptic drugs (AEDs and 15% continue to have seizure activity despite use of three drugs. Mechanisms that have made the treatment even more challenging are GABA-R that is internalized during status epilepticus and upregulation of multidrug transporter proteins. All patients of refractory status epilepticus require continuous EEG monitoring. There are three main agents used in the treatment of RSE. These include pentobarbital or thiopental, midazolam and propofol. RSE was shown to result in mortality in 35% cases, 39.13% of patients were left with severe neurological deficits, while another 13% had mild neurological deficits.

Refractory status epilepticus

Science.gov (United States)

Singh, Sanjay P; Agarwal, Shubhi; Faulkner, M

2014-01-01

Refractory status epilepticus is a potentially life-threatening medical emergency. It requires early diagnosis and treatment. There is a lack of consensus upon its semantic definition of whether it is status epilepticus that continues despite treatment with benzodiazepine and one antiepileptic medication (AED), i.e., Lorazepam + phenytoin. Others regard refractory status epilepticus as failure of benzodiazepine and 2 antiepileptic medications, i.e., Lorazepam + phenytoin + phenobarb. Up to 30% patients in SE fail to respond to two antiepileptic drugs (AEDs) and 15% continue to have seizure activity despite use of three drugs. Mechanisms that have made the treatment even more challenging are GABA-R that is internalized during status epilepticus and upregulation of multidrug transporter proteins. All patients of refractory status epilepticus require continuous EEG monitoring. There are three main agents used in the treatment of RSE. These include pentobarbital or thiopental, midazolam and propofol. RSE was shown to result in mortality in 35% cases, 39.13% of patients were left with severe neurological deficits, while another 13% had mild neurological deficits. PMID:24791086

Development of refractory concrete for extreme conditions

International Nuclear Information System (INIS)

Pundiene, I; Antonovich, V; Stonys, R; Demidova-Buiziniene, I

2011-01-01

Comparative analysis is provided for the properties of medium-cement refractory concrete with microsilica based on mullite filler in relation to different type of deflocculant. The effect of different deflocculants on refractory concrete structure formation, hydration, rheology, strength and heat resistance is discussed. Corrosion resistance test, determined that samples with hybrid deflocculant showed better resistance for slag penetration than samples with only the sodium tripolyphosphate or polycarboxylate ether deflocculant. Moreover, a composition of hybrid deflocculant let to control the rate of the hydration process and to get features of refractory refractory concrete.

High-Density Infrared Surface Treatments of Refractories

Energy Technology Data Exchange (ETDEWEB)

Tiegs, T.N.

2005-03-31

Refractory materials play a crucial role in all energy-intensive industries and are truly a crosscutting technology for the Industries of the Future (IOF). One of the major mechanisms for the degradation of refractories and a general decrease in their performance has been the penetration and corrosion by molten metals or glass. Methods and materials that would reduce the penetration, wetting, and corrosive chemistry would significantly improve refractory performance and also maintain the quality of the processed liquid, be it metal or glass. This report presents the results of an R&D project aimed at investigating the use of high-density infrared (HDI) heating to surface treat refractories to improve their performance. The project was a joint effort between Oak Ridge National Laboratory (ORNL) and the University of Missouri-Rolla (UMR). HDI is capable of heating the near-surface region of materials to very high temperatures where sintering, diffusion, and melting can occur. The intended benefits of HDI processing of refractories were to (1) reduce surface porosity (by essentially sealing the surface to prevent liquid penetration), (2) allow surface chemistry changes to be performed by bonding an adherent coating onto the underlying refractory (in order to inhibit wetting and/or improve corrosion resistance), and (3) produce noncontact refractories with high-emissivity surface coatings.

A Variational Approach to the Estimate of the Permittivity of a Composite with Dispersed Inclusions

Directory of Open Access Journals (Sweden)

V. S. Zarubin

2015-01-01

Full Text Available Composites are inhomogeneous materials (heterogeneous solid body, which fall into the matrix and inclusions. The matrix in a composite is a binder between the inclusions. The properties of the inclusions mainly determine the application of composites. Selection of the characteristics of the matrix and inclusions enables us to meet the requirements for materials to be used in various fields of technology. Composites are widely used as structural or thermal protection material and as functional materials in various electrical devices, including dielectrics. One of the most important characteristics of the composite dielectric is the relative permittivity. The latter is primarily determined by the dielectric properties of the matrix and inclusions, as well as the shape and volume concentration of inclusions.For a composite with dispersed inclusions we are able to construct adequate mathematical models which enable us to predict sufficiently reliably the dependence of its dielectric constant on these defining parameters. In this paper, among the various approaches to the construction of such models we emphasize a variational approach which allows us not only to determine this dependence, but also obtain guaranteed bilateral boundaries of the area of possible values of the dielectric constant of the composite used to estimate the highest accuracy of calculated values.The representative element of the composite structure with inclusions of spherical shape modeling the form of dispersed inclusions with dimensions close to all directions is considered. For the representative element we obtained the electrostatic potential distribution that is permissible for the minimized functional. The latter is the part of the variational form of a mathematical model which describes the dielectric properties of the considered composite. From the equality of the values of this functional on the received permissible distribution in a representative element of the

Genetics Home Reference: iron-refractory iron deficiency anemia

Science.gov (United States)

... refractory iron deficiency anemia Iron-refractory iron deficiency anemia Printable PDF Open All Close All Enable Javascript ... expand/collapse boxes. Description Iron-refractory iron deficiency anemia is one of many types of anemia , which ...

Refractory hypertension: definition, prevalence, and patient characteristics.

Science.gov (United States)

Acelajado, Maria Czarina; Pisoni, Roberto; Dudenbostel, Tanja; Dell'Italia, Louis J; Cartmill, Falynn; Zhang, Bin; Cofield, Stacey S; Oparil, Suzanne; Calhoun, David A

2012-01-01

Among patients with resistant hypertension (RHTN), there are those whose blood pressure (BP) remains uncontrolled in spite of maximal medical therapy. This retrospective analysis aims to characterize these patients with refractory hypertension. Refractory hypertension was defined as BP that remained uncontrolled after ≥3 visits to a hypertension clinic within a minimum 6-month follow-up period. Of the 304 patients referred for RHTN, 29 (9.5%) remained refractory to treatment. Patients with refractory hypertension and those with controlled RHTN had similar aldosterone levels and plasma renin activity (PRA). Patients with refractory hypertension had higher baseline BP (175±23/97±15 mm Hg vs 158±25/89±15 mm Hg; P=.001/.005) and heart rate, and higher rates of prior stroke and congestive heart failure. During follow-up, the BP of patients with refractory hypertension remained uncontrolled (168.4±14.8/93.8±17.7 mm Hg) in spite of use of an average of 6 antihypertensive medications, while those of patients with controlled RHTN decreased to 129.3±11.2/77.6±10.8 mm Hg. Spironolactone reduced the BP by 12.9±17.8/6.6±13.7 mm Hg in patients with refractory hypertension and by 24.1±16.7/9.2±12.0 mm Hg in patients with controlled RHTN. In patients with RHTN, approximately 10% remain refractory to treatment. Similar aldosterone and PRA levels and a diminished response to spironolactone suggest that aldosterone excess does not explain the treatment failure. © 2011 Wiley Periodicals, Inc.

Structural, mechanical and corrosion studies of Cr-rich inclusions in 152 cladding of dissimilar metal weld joint

Science.gov (United States)

Li, Yifeng; Wang, Jianqiu; Han, En-Hou; Yang, Chengdong

2018-01-01

Cr-rich inclusions were discovered in 152 cladding at the inner wall of domestic dissimilar metal weld joint, and their morphologies, microstructures, mechanical properties and corrosion behaviors were systematically characterized by SEM, TEM, nanoindentation and FIB. The results indicate that the Cr-rich inclusions originate from large-size Cr particles in 152 welding electrode flux, and they are 50-150 μm in size in most cases, and there is a continuous transition zone of 2-5 μm in width between the Cr inclusion core and 152 cladding matrix, and the transition zone consists of Ni & Fe-rich dendritic austenite and Cr23C6 and Cr matrix. The transition zone has the highest nanoindentation hardness (7.66 GPa), which is much harder than the inclusion core (5.14 GPa) and 152 cladding (3.71 GPa). In-situ microscopic tensile tests show that cracks initialize preferentially in transition zone, and then propagate into the inclusion core, and creep further into 152 cladding after penetrating the core area. The inclusion core and its transition zone both share similar oxide film structure with nickel-base 152 cladding matrix in simulated primary water, while those two parts present better general corrosion resistance than 152 cladding matrix due to higher Cr concentration.

Determination of the CKM-matrix element |V{sub ub}| from the electron energy spectrum measured in inclusive B→X{sub u}eν decay with the BABAR detector

Energy Technology Data Exchange (ETDEWEB)

Lueck, Thomas

2013-01-30

This document presents a measurement of the CKM matrix-element vertical stroke V{sub ub} vertical stroke in inclusive semileptonic B→X{sub u}eν events on a dataset of 471 million B anti B events recorded by the BABAR detector. Inclusive B→X{sub u}eν decays are selected by reconstructing a high energetic electron (positron). Background suppression is achieved by selecting events with electron (positron) energies near the kinematical allowed endpoint of B→X{sub u}eν decays. A B→D{sup *}eν veto is applied to further suppress background. This veto uses D{sup *} mesons which have been reconstructed with a partial reconstruction technique.

Nanosized f.c.c. thallium inclusions in aluminium

International Nuclear Information System (INIS)

Johnson, E.; Johansen, A.; Thoft, N.B.; Andersen, H.H.; Sarholt-Kristensen, L.

1993-01-01

Ion implantation of pure aluminium with thallium induces the formation of nanosized crystalline inclusions of thallium with a f.c.c. structure. The size of the inclusions depends on the implantation conditions and subsequent annealing treatments and is typically in the range from 1 to 10 nm. The inclusions are aligned topotactically with the aluminium matrix with a cube-cube orientation relationship and they have a truncated octahedral shape bounded by {111} and {001} planes. The lattice parameter of the f.c.c. thallium inclusions is 0.484 ± 0.002 nm, which is slightly but significantly larger than in the high-pressure f.c.c. thallium phase known to be stable above 3.8 GPa. (Author)

Outcomes in Children Treated with Pentobarbital Infusion for Refractory and Super-Refractory Status Epilepticus.

Science.gov (United States)

Erklauer, Jennifer; Graf, Jeanine; McPherson, Mona; Anderson, Anne; Wilfong, Angus; Minard, Charles G; Loftis, Laura

2018-03-26

Functional neurologic outcome for children with refractory and super-refractory status epilepticus has not been well defined. Retrospective chart review including children age 0-17 years who received pentobarbital infusion from 2003 to 2016 for status epilepticus. Outcomes were defined in terms of mortality, need for new medical technology assistance at hospital discharge and functional neurologic outcome determined by pediatric cerebral performance category score (PCPC). Potential patient characteristics associated with functional neurologic outcome including age, sex, ethnicity, etiology of the status epilepticus, and duration of pentobarbital infusion were evaluated. Forty children met inclusion criteria. In-hospital mortality was 30% (12/40). Of survivors, 21% (6/28) returned to baseline PCPC while half (14/28) declined in function ≥ 2 PCPC categories at hospital discharge. 25% (7/28) of survivors required tracheostomy and 27% (7/26) required new gastrostomy. Seizures persisted at discharge for most patients with new onset status epilepticus while the majority of patients with known epilepsy returned to baseline seizure frequency. Etiology (p = 0.015), PCPC at admission (p = 0.0006), new tracheostomy (p = 0.012), and new gastrostomy tube (p = 0.012) were associated with increase in PCPC score ≥ 2 categories in univariable analysis. Duration of pentobarbital infusion (p = 0.005) and length of hospital stay (p = 0.056) were longer in patients who demonstrated significant decline in neurologic function. None of these variables maintained statistical significance when multiple logistic regression model adjusting for PCPC score at admission was applied. At long-term follow-up, 36% (8/22) of children demonstrated improvement in PCPC compared to discharge and 23% (5/22) showed deterioration including three additional deaths. Mortality in this population was high. The majority of children experienced some degree of disability at discharge. Despite

Refractories for Industrial Processing. Opportunities for Improved Energy Efficiency

Energy Technology Data Exchange (ETDEWEB)

Hemrick, James G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hayden, H. Wayne [Metals Manufacture Process and Controls Technology, Inc., Oak Ridge, TN (United States); Angelini, Peter [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Moore, Robert E. [R.E. Moore Associates, Maricopa, AZ (United States); Headrick, William L. [R.E. Moore Associates, Maricopa, AZ (United States)

2005-01-01

Refractories are a class of materials of critical importance to manufacturing industries with high-temperature unit processes. This study describes industrial refractory applications and identifies refractory performance barriers to energy efficiency for processing. The report provides recommendations for R&D pathways leading to improved refractories for energy-efficient manufacturing and processing.

Molybdenite in calcium-aluminum-rich inclusions in the Allende meteorite

Science.gov (United States)

Fuchs, L. H.; Blander, M.

1977-01-01

The first observations of molybdenite in a meteorite have been made in two Ca-Al-rich inclusions in the Allende chondrite. The mineral occurs as single individuals completely enclosed in high Ni metal (62-64.5 wt. % Ni). The association with refractories is consistent with thermodynamic calculations which predict that Mo is a high temperature condensate even when nucleation constraints are imposed on the formation of a metal phase. Kinetic factors (including nucleation constraints) appear to have played an important role in the formation of molybdenite and the associated sulfides, magnetite and high nickel metal.

Advanced ceramic matrix composites for high energy x-ray generation

International Nuclear Information System (INIS)

Khan, Amir Azam; Labbe, Jean Claude

2011-01-01

High energy x-ray targets are the anodes used in high performance tubes, designed to work for long operating times and at high power. Such tubes are used in computed tomography (CT) scan machines. Usually the tubes used in CT scanners have to continuously work at high temperatures and for longer scan durations in order to get maximum information during a single scan. These anodes are composed of a refractory substrate which supports a refractory metallic coating. The present work is a review of the development of a ceramic metal composite based on aluminium nitride (AlN) and molybdenum for potential application as the substrate. This composite is surface engineered by coating with tungsten, the most popular material for high energy x-ray targets. To spray metallic coatings on the surface of ceramic matrix composites dc blown arc plasma is employed. The objective is to increase the performance and the life of an x-ray tube. Aluminium nitride-molybdenum ceramic matrix composites were produced by uniaxial hotpressing mixtures of AlN and Mo powders. These composites were characterized for their mechanical, thermal, electrical and micro-structural properties. An optimized composition was selected which contained 25 vol.% of metallic phase dispersed in the AlN matrix. These composites were produced in the actual size of an anode and coated with tungsten through dc blown arc plasma spraying. The results have shown that sintering of large size anodes is possible through uniaxial pressing, using a modified sintering cycle

Medical versus surgical treatment for refractory or recurrent peptic ulcer.

Science.gov (United States)

Gurusamy, Kurinchi Selvan; Pallari, Elena

2016-03-29

Refractory peptic ulcers are ulcers in the stomach or duodenum that do not heal after eight to 12 weeks of medical treatment or those that are associated with complications despite medical treatment. Recurrent peptic ulcers are peptic ulcers that recur after healing of the ulcer. Given the number of deaths due to peptic ulcer-related complications and the long-term complications of medical treatment (increased incidence of fracture), it is unclear whether medical or surgical intervention is the better treatment option in people with recurrent or refractory peptic ulcers. To assess the benefits and harms of medical versus surgical treatment for people with recurrent or refractory peptic ulcer. We searched the specialised register of the Cochrane Upper GI and Pancreatic Diseases group, the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, and trials registers until September 2015 to identify randomised trials and non-randomised studies, using search strategies. We also searched the references of included studies to identify further studies. We considered randomised controlled trials and non-randomised studies comparing medical treatment with surgical treatment in people with refractory or recurrent peptic ulcer, irrespective of language, blinding, or publication status for inclusion in the review. Two review authors independently identified trials and extracted data. We planned to calculate the risk ratio, mean difference, standardised mean difference, or hazard ratio with 95% confidence intervals using both fixed-effect and random-effects models with Review Manager 5 based on intention-to-treat analysis. We included only one non-randomised study published 30 years ago in the review. This study included 77 participants who had gastric ulcer and in whom medical therapy (histamine H2 receptor blockers, antacids, and diet) had failed after an average duration of treatment of 29 months. The

Effect of inclusions modified by rare earth elements (Ce, La) on localized marine corrosion in Q460NH weathering steel

International Nuclear Information System (INIS)

Liu, Chao; Revilla, Reynier I.; Liu, Zhiyong; Zhang, Dawei; Li, Xiaogang; Terryn, Herman

2017-01-01

Highlights: •The initial stages of the pitting corrosion of Q460NH steel in a marine environment was studied. •Two different types of inclusions formed in the Q460NH steel after adding rare earth. •Both types of inclusions showed a lower Volta potential than the matrix. •Pitting corrosion was induced by the dissolution of inclusions rather than the matrix. •Inclusions containing (RE)AlO 3 dissolved completely as a result of the acidic solution formed in the pits. -- Abstract: In this work the initial stages of the pitting corrosion in Q460NH weathering steel in a marine environment was studied. To elucidate the effects of inclusions modified by rare earth (RE) elements on pitting corrosion, field emission-scanning electron microscopy-energy dispersive spectrometry (FE-SEM-EDS) analyses, scanning Kelvin probe force microscopy (SKPFM) tests, and a series of immersion tests were conducted. Two main types of inclusions were formed in the steel, and different pit morphologies were observed. The pitting corrosion was initiated by the dissolution of (RE) 2 O 2 S-(RE)xSy in both types of inclusions due to the lower potential of this phase compared to the matrix, which indicated that the inclusions in the Q460NH weathering steel had a lower pitting corrosion resistance than the matrix.

The estimate of permittivity of anisotropic composites with lamellar inclusions by the self-assessment method

Directory of Open Access Journals (Sweden)

V. S. Zarubin

2015-01-01

Full Text Available Composites are widely used as structural or thermal protection materials; they are used as well as functional materials in a large number of different electrical devices and as dielectrics. This composite has one of the most important characteristics the relative permittivity. It depends primarily on the dielectric properties of the inclusions and the matrix as well as the shape and volume content of the inclusions.In this paper, a mathematical model of the interaction of the electrostatic fields in an isotropic plate and in the surrounding homogeneous anisotropic medium is constructed. This model describes the dielectric properties of the composite with such inclusions. A variant of the same orientation of lamellar inclusions is considered, which leads to the special case of anisotropy of the dielectric properties of the composite that has transverse isotropy towards the direction perpendicular to the inclusions. The shape of inclusions is represented as an oblate ellipsoid of revolution (spheroid. Transformation of the differential equation describing the distribution of the electric potential transversely to isotropic medium surrounding the spheroidal inclusion, to the Laplace equation with the subsequent transition from the initial spheroid to the given ellipsoid of rotation allows us to apply the self-assessment method for the determination of the dielectric properties of the composite. This method equates the result of averaging the perturbation of the electrostatic field in the inclusions and the matrix particles towards the unperturbed fields in the environment to zero.The constructed mathematical model allows us to determine the electrostatic field disturbance in the inclusions and the matrix particles towards the unperturbed field given in the environment at a distance from the inclusions and the matrix particles, much larger than their characteristic dimensions. By averaging the perturbation of the electrostatic field in all the

Potential refractory alloy requirements for space nuclear power applications

International Nuclear Information System (INIS)

Cooper, R.H. Jr.

1984-01-01

In reviewing design requirements for refractory alloys for space nuclear applications, several key points are identified. First, the successful utilization of refractory alloys is considered an enabling requirement for the successful deployment of high efficiency, lightweight, and small space nuclear systems. Second, the recapture of refractory alloy nuclear technology developed in the 1960s and early 1970s appears to be a pacing activity in the successful utilization of refractory alloys. Third, the successful application of refractory alloys for space nuclear applications will present a significant challenge to both the materials and the systems design communities

Refractories for steel-works

International Nuclear Information System (INIS)

Villanova, R.A.; Galant, C.L.; Haas, C.; Rosenbaum, V.

The routine procedures utilized for quality control of refractory materials used by PIRATINI's steel-works, are presented ' under an objetive and practical maner. The attention of the paper is concentrated upon the following' refractory types with higher consume: silicon-aluminous; aluminous; basic magnesia; basic chrom-magnesia. All steps of utilization are described, including specification, supplies programation, storage; sampling; physical tests, and also aplication procedures. Results from routine analysis during a six month period, by ' means of X-Ray Quantometry, using the fusion pearls procedure, are presented compared with Atomic Absorption [pt

Development of AZS refractories for the glass industry

International Nuclear Information System (INIS)

Guzman, A.M.; Rodriguez, P.

2004-01-01

Refractory materials can support high temperatures, thermal strength and the contact with aggressive environments, for this reason they are widely used in the cement, glass and steel industry. Commercial AZS (alumina-zirconia-silica) refractories are a good alternative in refractory materials for the glass industry' because they can support the aggressive conditions during liquid processing of glass. However, another problem encountered in glass industry is contamination by refractory' material that fall into the molten glass, which can produce a series of defects in the final product. This research was conducted to develop new formulations of AZS refractories with different amounts of ZrO 2 with the purpose of improving the characteristics, properties and the work conditions in the glass melting furnaces and, at the same time, lower the costs this type of refractories. The results obtained indicate that the composition with low content of ZrO 2 can provide better properties than the commercial product, with some modifications in the particle size distribution. Copyright (2004) AD-TECH - International Foundation for the Advancement of Technology Ltd

Inclusive cross sections in ME+PS merging

International Nuclear Information System (INIS)

Plaetzer, Simon

2013-07-01

We discuss an extension of matrix element plus parton shower merging at leading and next-to-leading order. The algorithm does preserve inclusive cross sections at the respective input order. This constraint avoids potentially large logarithmic contributions, which would require approximate (N)NLO contributions to cancel against.

Mathematical Modeling of Dielectric Characteristics of the Metallic Band Inclusion Composite

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V. S. Zarubin

2015-01-01

Full Text Available Among the desirable properties of functional materials used in various electrical and radio physical equipment and devices, dielectric characteristics, including relative permittivity (hereinafter, permittivity are of importance. The permittivity requirements can be met when a composite with a particular combination of its matrix characteristics and inclusions [1, 2, 3] is used as a functional material. The use of metallic inclusions extends a variation range of dielectric characteristics of the composite, and thereby enhances its application. The composite structure, form of inclusions, and their volume concentration has a significant impact on the permittivity.One of the composite structure embodiments is a dispersion system when in the dispersion medium (in this case | in the composite matrix a dispersed phase (inclusions with highly extended interface between them [4] is distributed. There can be various forms of dispersed inclusions. Band is one of the possible forms of inclusion when its dimensions in three orthogonal directions are significantly different among themselves. For such inclusion, a tri-axial ellipsoid can be taken as an acceptable geometric model to describe its form. This model can be used, in particular, to describe the form of nanostructured elements, which recently are considered as inclusions for advanced composites for various purposes [5].With raising volume concentration of metal inclusions in the dielectric matrix composite there is an increasing probability of direct contact between the inclusions resulting in continuous conductive cluster [3, 6]. In this paper, it is assumed that metal band inclusions are covered with a sufficiently thin layer of the electrically insulating material, eliminating the possibility of direct contact and precluding consideration of the so-called percolation effect [2, 7] in the entire interval of the expectedly changing volume concentration of electrically ellipsoidal inclusions. The

Refractory migraine in a headache clinic population

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Fernandez-Torron Roberto

2011-08-01

Full Text Available Abstract Background Many migraineurs who seek care in headache clinics are refractory to treatment, despite advances in headache therapies. Epidemiology is poorly characterized, because diagnostic criteria for refractory migraine were not available until recently. We aimed to determine the frequency of refractory migraine in patients attended in the Headache Unit in a tertiary care center, according to recently proposed criteria. Methods The study population consisted of a consecutive sample of 370 patients (60.8% females with a mean age of 43 years (range 14-86 evaluated for the first time in our headache unit over a one-year period (between October 2008 and October 2009. We recorded information on clinical features, previous treatments, Migraine Disability Assessment Score (MIDAS, and final diagnosis. Results Overall migraine and tension-type headache were found in 46.4% and 20.5% of patients, respectively. Refractory migraine was found in 5.1% of patients. In refractory migraineurs, the mean MIDAS score was 96, and 36.8% were medication-overusers. Conclusions Refractory migraine is a relatively common and very disabling condition between the patients attended in a headache unit. The proposed operational criteria may be useful in identifying those patients who require care in headache units, the selection of candidates for combinations of prophylactic drugs or invasive treatments such as neurostimulation, but also to facilitate clinical studies in this patient group.

NOvel Refractory Materials for High Alkali, High Temperature Environments

Energy Technology Data Exchange (ETDEWEB)

Hemrick, J.G.; Griffin, R. (MINTEQ International, Inc.)

2011-08-30

Refractory materials can be limited in their application by many factors including chemical reactions between the service environment and the refractory material, mechanical degradation of the refractory material by the service environment, temperature limitations on the use of a particular refractory material, and the inability to install or repair the refractory material in a cost effective manner or while the vessel was in service. The objective of this project was to address the need for new innovative refractory compositions by developing a family of novel MgO-Al2O3 spinel or other similar magnesia/alumina containing unshaped refractory composition (castables, gunnables, shotcretes, etc) utilizing new aggregate materials, bond systems, protective coatings, and phase formation techniques (in-situ phase formation, altered conversion temperatures, accelerated reactions, etc). This family of refractory compositions would then be tailored for use in high-temperature, highalkaline industrial environments like those found in the aluminum, chemical, forest products, glass, and steel industries. A research team was formed to carry out the proposed work led by Oak Ridge National Laboratory (ORNL) and was comprised of the academic institution Missouri University of Science and Technology (MS&T), and the industrial company MINTEQ International, Inc. (MINTEQ), along with representatives from the aluminum, chemical, glass, and forest products industries. The two goals of this project were to produce novel refractory compositions which will allow for improved energy efficiency and to develop new refractory application techniques which would improve the speed of installation. Also methods of hot installation were sought which would allow for hot repairs and on-line maintenance leading to reduced process downtimes and eliminating the need to cool and reheat process vessels.

SINTERED REFRACTORY TUNGSTEN ALLOYS. Gesinterte hochschmelzende wolframlegierungen

Energy Technology Data Exchange (ETDEWEB)

Kieffer, R.; Sedlatschek, K.; Braun, H.

1971-12-15

Dependence of the melting point of the refractory metals on their positions in the periodic system - alloys of tungsten with other refractory metals - sintering of the alloys - processing of the alloys - technological properties.

Stochastic histories of refractory interstellar dust

International Nuclear Information System (INIS)

Liffman, K.; Chayton, D.D.

1988-01-01

The authors calculate histories for refractory dust particles in the interstellar medium. The double purposes are to learn something of the properties of interstellar dust as a system and to evaluate with specific assumptions the cosmic chemical memory interpretation of a specific class of isotopic anomalies. They assemble the profile of a particle population from a large number of stochastic, or Monte Carlo, histories of single particles, which are necessarily taken to be independent with this approach. They specify probabilities for each of the events that may befall a given particle and unfold its history by a sequence of random numbers. They assume that refractory particles are created only by thermal condensation within stellar material during its ejection from stars, and that these refractory particles can be destroyed only by being sputtered to a size too small for stability or by being incorporated into the formation of new stars. In order to record chemical detail, the authors take each new refractory particle to consist of a superrefractory core plus a more massive refractory mantle. They demonstrate that these superrefractory cores have effective lifetimes much longer than the turnover time of dust mass against sputtering. As examples of cosmic chemical memory they evaluate the 16 O-richness of interstellar aluminum and mechanisms for the 48 Ca/ 50 Ti correlation. Several related consequences of this approach are discussed

Response properties of the refractory auditory nerve fiber.

Science.gov (United States)

Miller, C A; Abbas, P J; Robinson, B K

2001-09-01

The refractory characteristics of auditory nerve fibers limit their ability to accurately encode temporal information. Therefore, they are relevant to the design of cochlear prostheses. It is also possible that the refractory property could be exploited by prosthetic devices to improve information transfer, as refractoriness may enhance the nerve's stochastic properties. Furthermore, refractory data are needed for the development of accurate computational models of auditory nerve fibers. We applied a two-pulse forward-masking paradigm to a feline model of the human auditory nerve to assess refractory properties of single fibers. Each fiber was driven to refractoriness by a single (masker) current pulse delivered intracochlearly. Properties of firing efficiency, latency, jitter, spike amplitude, and relative spread (a measure of dynamic range and stochasticity) were examined by exciting fibers with a second (probe) pulse and systematically varying the masker-probe interval (MPI). Responses to monophasic cathodic current pulses were analyzed. We estimated the mean absolute refractory period to be about 330 micros and the mean recovery time constant to be about 410 micros. A significant proportion of fibers (13 of 34) responded to the probe pulse with MPIs as short as 500 micros. Spike amplitude decreased with decreasing MPI, a finding relevant to the development of computational nerve-fiber models, interpretation of gross evoked potentials, and models of more central neural processing. A small mean decrement in spike jitter was noted at small MPI values. Some trends (such as spike latency-vs-MPI) varied across fibers, suggesting that sites of excitation varied across fibers. Relative spread was found to increase with decreasing MPI values, providing direct evidence that stochastic properties of fibers are altered under conditions of refractoriness.

Refractory alloy technology for space nuclear power applications

International Nuclear Information System (INIS)

Cooper, R.H. Jr.; Hoffman, E.E.

1984-01-01

Purpose of this symposium is twofold: (1) to review and document the status of refractory alloy technology for structural and fuel-cladding applications in space nuclear power systems, and (2) to identify and document the refractory alloy research and development needs for the SP-100 Program in both the short and the long term. In this symposium, an effort was made to recapture the space reactor refractory alloy technology that was cut off in midstream around 1973 when the national space nuclear reactor program began in the early 1960s, was terminated. The six technical areas covered in the program are compatibility, processing and production, welding and component fabrication, mechanical and physical properties, effects of irradiation, and machinability. The refractory alloys considered are niobium, molybdenum, tantalum, and tungsten. Thirteen of the 14 pages have been abstracted separately. The remaining paper summarizes key needs for further R and D on refractory alloys

Electrophysical properties of crystals with superconducting inclusions of small sizes

International Nuclear Information System (INIS)

Sugakov, V.I.; Shevtsova, O.N.

2001-01-01

The effect of superconducting inclusions, incorporated in a semiconducting or dielectric matrix, on the electrophysical properties of the dielectric is studied. The critical magnetic field of a spherical isolated inclusion is determined in the assumption that the inclusion radius is less than or of the order of coherence length. The dependence of conductivity on temperature and magnetic field is calculated for a crystal with superconducting inclusions. In the calculations an assumption is made that the inclusion concentration is inadequate for the superconductivity to appear in a whole sample (i.e. below the thresh-old of percolation). It is shown that the presence of superconducting inclusions leads to a sharp increase of the sample conductivity at low temperatures, and to a strong dependence of conductivity on magnetic field (magnetoresistance). The magnetoresistance is caused by suppression of superconductivity in the inclusions with increasing magnetic field. The influence of variations in inclusion size on the temperature and magnetic field dependences of conductivity is studied

An investigation into mineral processing of north Semnan refractory earth

International Nuclear Information System (INIS)

Aslani, S.; Samin-Bani-Hashemi, H.R.; Taghi-Zadeh, O.

2002-01-01

This paper is dealing with refractory earth of North Semnan. Having an area of 2000 square kilometers, Semnan province is mainly formed by sedimentary rocks with a verity of refractory earth, red earth and kaolin containing heavy minerals. The refractory earth of this area contains a considerable rate of aluminum oxide in shape of dia spore minerals, behemoth and gybsite along with heavy minerals of iron and titanium. To improve the quality of refractory earth, in order to be used in related industries, these minerals have to be separated. To assess the quality of refractory earth of North Semnan as the raw materials of refractory industries, their genesis and mineralogy properties have been precisely studied. Based on the rate of aluminium oxide of the refractory earth of North Semnan mines, a suitable mineral deposit has been selected for more investigation. Using XRD and X RF methods along with electronic and photo microscopes, the refractory earth and heavy minerals of them have been assessed. The elementary laboratory experiments of fragmentation and magnetic separation have been performed. It has been proved that the iron minerals can be separated and, therefore, the quality of the refractory earth can be improved. The separation of titanium minerals has to be investigated with other methods

REFRACTORY THROMBOCYTOPENIA AND NEUTROPENIA: A DIAGNOSTIC CHALLENGE

Directory of Open Access Journals (Sweden)

Emmanuel Gyan

2015-02-01

Full Text Available Background. The 2008 WHO classification identified refractory cytopenia with unilineage dysplasia (RCUD as a composite entity encompassing refractory anemia, refractory thrombocytopenia (RT, and refractory neutropenia (RN, characterized by 10% or more dysplastic cells in the bone marrow respective lineage. The diagnosis of RT and RN is complicated by several factors.  Diagnosing RT first requires exclusion of familial thrombocytopenia, chronic auto-immune thrombocytopenia, concomitant medications, viral infections, or hypersplenism. Diagnosis of RN should also be made after ruling out differential diagnoses such as ethnic or familial neutropenia, as well as acquired, drug-induced, infection-related or malignancy-related neutropenia. An accurate quantification of dysplasia should be performed in order to distinguish RT or RN from the provisional entity named idiopathic cytopenia of unknown significance (ICUS. Cytogenetic analysis, and possibly in the future somatic mutation analysis (of genes most frequently mutated in MDS, and flow cytometry analysis aberrant antigen expression on myeloid cells may help in this differential diagnosis. Importantly, we and others found that, while isolated neutropenia and thrombocytopenia are not rare in MDS, those patients can generally be classified (according to WHO 2008 classification as refractory cytopenia with multilineage dysplasia or refractory anemia with excess blasts, while RT and RN (according to WHO 2008 are quite rare.These results suggest in particular that identification of RT and RN as distinct entities could be reconsidered in future WHO classification updates.

Analysis of teacher relations with teaching in classroom with prospects to be inclusive.

Directory of Open Access Journals (Sweden)

Angela Meneghello Passos

2015-12-01

Full Text Available This article presents a proposal for the analysis of teaching relationships in the classroom with prospects of being inclusive, having as theoretical support an instrument called 3x3 matrix. This matrix enables us to understand the actions of the teacher in the classroom based on the relationship with knowledge, teaching and learning in epistemic, personal and social dimensions. The main question that guided this research was: What teacher relationships is possible to see in a classroom with prospects of being inclusive? The methodological procedures were based on discursive textual analysis. Among other, results provided by this research are: the evidence that there is an increase in teaching tasks in the classroom with prospects to be inclusive; the need to expand the 3x3 matrix to accommodate the new teacher relations; and that the presence of the student with disabilities changes the classroom setting and stimulates the concern of the teacher with learning leading him to pay attention to the social dimension of the relationship with knowledge.

Corrosão de refratários utilizados na siderurgia. Parte II: propriedades físicas dos refratários e fatores operacionais Corrosion of refractories used in steel metallurgy. Part II: refractories physical properties and operating factor

Directory of Open Access Journals (Sweden)

S. R. Bragança

2012-12-01

Full Text Available Foi realizada uma revisão dos principais aspectos encontrados na literatura especializada sobre corrosão de refratários, avaliando-se a viabilidade de determinados ensaios e relacionando-os com os resultados experimentais. Na primeira parte deste trabalho foram abordadas as principais propriedades da microestrutura dos refratários, como a qualidade dos agregados e da matriz, incluindo-se a fase ligante (como resinas ou piche, presença de carbono, porosidade e aditivos antioxidantes. Nesta segunda parte os demais aspectos ligados à corrosão, como as propriedades físico-químicas dos refratários, as características das escórias e das condições operacionais são discutidas, sempre, relacionando-se a teoria com dados da prática industrial. Especificamente, analisaram-se os refratários de linha de escória de panela de aço.In this study, the main aspects found in the literature about refractories corrosion were reviewed, evaluating the feasibility of certain tests and relating them with experimental results. In the first part of this work, the main properties of the microstructure of the refractories were discussed, such as aggregates and the matrix, including the binder phase (resins or pitch, presence of carbon, porosity, additives and anti-oxidants. In this second part, the remaining aspects of corrosion, such as physical and chemical properties of refractories, slag characteristics and operating conditions are discussed, linking the theory with data from industrial practice. Specifically, it was analyzed the refractory from slag-line of steel ladle.

Refractory alloy technology for space nuclear power applications

Energy Technology Data Exchange (ETDEWEB)

Cooper, R.H. Jr.; Hoffman, E.E. (eds.)

1984-01-01

Purpose of this symposium is twofold: (1) to review and document the status of refractory alloy technology for structural and fuel-cladding applications in space nuclear power systems, and (2) to identify and document the refractory alloy research and development needs for the SP-100 Program in both the short and the long term. In this symposium, an effort was made to recapture the space reactor refractory alloy technology that was cut off in midstream around 1973 when the national space nuclear reactor program began in the early 1960s, was terminated. The six technical areas covered in the program are compatibility, processing and production, welding and component fabrication, mechanical and physical properties, effects of irradiation, and machinability. The refractory alloys considered are niobium, molybdenum, tantalum, and tungsten. Thirteen of the 14 pages have been abstracted separately. The remaining paper summarizes key needs for further R and D on refractory alloys. (DLC)

Temperature and Thermal Stress Analysis of Refractory Products

Directory of Open Access Journals (Sweden)

Shaoyang Shi

2013-05-01

Full Text Available Firstly current status of temperature and thermal stress research of refractory product at home and aboard are analyzed. Finite element model of two classical refractory products is building by using APDL language. Distribution law of temperature and thermal stress of two typical refractory products-ladles and tundish are analyzed and their structures are optimized. Stress of optimal structure is dropped obviously, and operation life is increased effectively.

High Temperature Sliding Wear of NiAl-based Coatings Reinforced by Borides

Directory of Open Access Journals (Sweden)

Oleksandr UMANSKYI

2016-05-01

Full Text Available The development of composite materials (CM in the systems “metal-refractory compound” is one of the up-to-date trends in design of novel materials aimed at operating under the conditions of significant loads at high temperature. To design such material, NiAl, which is widely used for deposition of protective coatings on parts of gas-turbine engines, was selected for a matrix. To strengthen a NiAl under the conditions of intense wear and a broad temperature range (up to 1000 °C, it is reasonable to add refractory inclusions. Introduction of refractory borides into matrix leads to a marked increase in metal wear resistance. In order to research the behavior of the designed composites at high temperatures and to study the influence of oxides on the friction processes, the authors carried out high temperature oxidation of CM of the above systems at 1000 °С for 90 min. It was determined that all of the composites were oxidized selectively and that the thickness of oxide layers formed on the boride inclusions is 3 – 7 times that on the oxides formed on the NiAl matrix. The mechanism of wear of gas-thermal coatings of the NiAl – МеB2 systems was studied for conditions of high temperature tribotests using the «pin-on-disc» technique. The obtained results indicate that introduction of TiB2, CrB2 and ZrB2 leads to their more intense oxidation during high temperature tribotests as compared to the matrix. The oxides formed on refractory borides act as solid lubricants, which promote a decrease in wear of the contact friction pairs. For more detailed investigation of the effect of tribo-oxidation products on the friction processes, tribotests were conducted for prior oxidized (at 900 °С coatings NiAl – 15 wt.% CrB2 (TiB2, ZrB2.DOI: http://dx.doi.org/10.5755/j01.ms.22.1.8093

Oxygen isotope exchange between refractory inclusion in allende and solar nebula Gas

Science.gov (United States)

Yurimoto; Ito; Nagasawa

1998-12-04

A calcium-aluminum-rich inclusion (CAI) from the Allende meteorite was analyzed and found to contain melilite crystals with extreme oxygen-isotope compositions ( approximately 5 percent oxygen-16 enrichment relative to terrestrial oxygen-16). Some of the melilite is also anomalously enriched in oxygen-16 compared with oxygen isotopes measured in other CAIs. The oxygen isotopic variation measured among the minerals (melilite, spinel, and fassaite) indicates that crystallization of the CAI started from oxygen-16-rich materials that were probably liquid droplets in the solar nebula, and oxygen isotope exchange with the surrounding oxygen-16-poor nebular gas progressed through the crystallization of the CAI. Additional oxygen isotope exchange also occurred during subsequent reheating events in the solar nebula.

Optics of Water Microdroplets with Soot Inclusions: Exact Versus Approximate Results

Science.gov (United States)

Liu, Li; Mishchenko, Michael I.

2016-01-01

We use the recently generalized version of the multi-sphere superposition T-matrix method (STMM) to compute the scattering and absorption properties of microscopic water droplets contaminated by black carbon. The soot material is assumed to be randomly distributed throughout the droplet interior in the form of numerous small spherical inclusions. Our numerically-exact STMM results are compared with approximate ones obtained using the Maxwell-Garnett effective-medium approximation (MGA) and the Monte Carlo ray-tracing approximation (MCRTA). We show that the popular MGA can be used to calculate the droplet optical cross sections, single-scattering albedo, and asymmetry parameter provided that the soot inclusions are quasi-uniformly distributed throughout the droplet interior, but can fail in computations of the elements of the scattering matrix depending on the volume fraction of soot inclusions. The integral radiative characteristics computed with the MCRTA can deviate more significantly from their exact STMM counterparts, while accurate MCRTA computations of the phase function require droplet size parameters substantially exceeding 60.

Quark correlation functions in deep-inelastic semi-inclusive processes

International Nuclear Information System (INIS)

Levelt, J.; Mulders, P.J.

1994-01-01

We investigate one-particle semi-inclusive processes in lepton-hadron scattering. In unpolarized scattering order Q -1 corrections appear only when transverse momenta are detected. We consider the twist-two and -three matrix elements and calculate the semi-inclusive structure functions in terms of quark correlation functions. We find that at the twist-three level not only the standard quark distribution and fragmentation function contribute, but also two new transverse ''profile functions.'' We discuss the gauge invariance of the hadronic tensor at the twist-three level. The results of our approach are used to calculate expressions for some cross sections for semi-inclusive processes

Comparative evaluation of the locally manufactured low-alumina fireclay refractories

International Nuclear Information System (INIS)

Mohammad, D.; Ahmed, W.; Khan, M.I.

2007-01-01

Properties of domestically produced low-alumina refractories commonly known as medium duty fireclay refractories were studied and a comparative evaluation was performed. Refractory properties such as density, porosity, cold strength, reheat change and deformation at high-temperature were determined. Significant differences were discovered between these products sold as medium duty fireclay refractories. One brand marketed as medium duty refractory was found to be too inferior to be designated as medium duty firebrick. Absence of any standards and lack of awareness on the part of users of the various test methods appear to be the cause of this situation. (author)

Micromechanical study of the effect of inclusions on fatigue failure in a roller bearing

DEFF Research Database (Denmark)

Cerullo, Michele; Tvergaard, Viggo

2015-01-01

model containing a single inclusion, using the approximation of a 2D plane strain numerical analysis. The Dang Van multiaxial fatigue criterion is used for the local stresses in the matrix material, to ensure that the stresses remain within the fatigue limit. The matrix material is taken to be one...... of the most commonly used bearing steels, AISI 52100, and two different types of inclusions are considered. The macroscopic stress histories applied correspond to either a Hertzian or an elastohydrodynamic (EHL) contact pressure distribution under the rollers. Findings - The paper shows that sub...

Directed light fabrication of refractory metals and alloys

International Nuclear Information System (INIS)

Fonseca, J.C.; Lewis, G.K.; Dickerson, P.G.; Nemec, R.B.

1999-01-01

This report covers deposition of refractory pure metals and alloys using the Directed Light Fabrication (DLF) process and represents progress in depositing these materials through September 1998. In extending the DLF process technology to refractory metals for producing fully dense, structurally sound deposits, several problems have become evident. (1) Control of porosity in DLF-deposited refractory metal is difficult because of gases, apparently present in commercially purchased refractory metal powder starting materials. (2) The radiant heat from the molten pool during deposition melts the DLF powder feed nozzle. (3) The high reflectivity of molten refractory metals, at the Nd-YAG laser wavelength (1.06microm), produces damaging back reflections to the optical train and fiber optic delivery system that can terminate DLF processing. (4) The current limits on the maximum available laser power to prevent back reflection damage limit the parameter range available for densification of refractory metals. The work to date concentrated on niobium, W-25Re, and spherodized tungsten. Niobium samples, made from hydride-dehydride powder, had minimal gas porosity and the deposition parameters were optimized; however, test plates were not made at this time. W-25Re samples, containing sodium and potassium from a precipitation process, were made and porosity was a problem for all samples although minimized with some process parameters. Deposits made from potassium reduced tungsten that was plasma spherodized were made with minimized porosity. Results of this work indicate that further gas analysis of starting powders and de-gassing of starting powders and/or gas removal during deposition of refractory metals is required

Lenvatinib in Advanced Radioiodine-Refractory Thyroid Cancer - A Retrospective Analysis of the Swiss Lenvatinib Named Patient Program.

Science.gov (United States)

Balmelli, Catharina; Railic, Nikola; Siano, Marco; Feuerlein, Kristin; Cathomas, Richard; Cristina, Valerie; Güthner, Christiane; Zimmermann, Stefan; Weidner, Sabine; Pless, Miklos; Stenner, Frank; Rothschild, Sacha I

2018-01-01

Purpose: Differentiated thyroid cancer (DTC) accounts for approximately 95% of thyroid carcinomas. In the metastatic RAI-refractory disease, chemotherapy has very limited efficacy and is associated with substantial toxicity. With increasing knowledge of the molecular pathogenesis of DTC, novel targeted therapies have been developed. Lenvatinib is a tyrosine kinase inhibitor (TKI) with promising clinical activity based on the randomized phase III SELECT trial. In Switzerland, a Named Patient Program (NPP) was installed to bridge the time gap to Swissmedic approval. Here, we report the results from the Swiss Lenvatinib NPP including patients with metastatic RAI-refractory DTC. Methods: Main inclusion criteria for the Swiss NPP were RAI-refractory DTC, documented disease progression, Eastern Cooperative Oncology Group (ECOG) performance status 0-3. The number of previous therapies was not limited. The Swiss Lenvatinib NPP was initiated in June 2014 and was closed in October 2015 with the approval of the drug. Results: Between June 2014 and October 2015, 13 patients with a median age of 72 years have been enrolled. Most patients (69%) had at least one prior systemic therapy, mainly sorafenib. 31% of patients showed a PR and 31% SD. Median progression free survival was 7.2 months and the median overall survival was 22.7 months. Dose reduction due to adverse events was necessary in 7 patients (53%). At the time of analysis 6 patients (47%) were still on treatment with a median time on treatment of 9.98 months. Conclusions: Our results show that lenvatinib has reasonable clinical activity in unselected patients with RAI-refractory thyroid cancer with nearly two-third of patients showing clinical benefit. The toxicity profile of lenvatinib is manageable.

Inclusion bodies of aggregated hemosiderins in liver macrophages.

Science.gov (United States)

Hayashi, Hisao; Tatsumi, Yasuaki; Wakusawa, Shinya; Shigemasa, Ryota; Koide, Ryoji; Tsuchida, Ken-Ichi; Morotomi, Natsuko; Yamashita, Tetsuji; Kumagai, Kotaro; Ono, Yukiya; Hayashi, Kazuhiko; Ishigami, Masatoshi; Goto, Hidemi; Kato, Ayako; Kato, Koichi

2017-12-01

Hemosiderin formation is a structural indication of iron overload. We investigated further adaptations of the liver to excess iron. Five patients with livers showing iron-rich inclusions larger than 2 µm were selected from our database. The clinical features of patients and structures of the inclusions were compared with those of 2 controls with mild iron overload. All patients had severe iron overload with more than 5000 ng/mL of serum ferritin. Etiologies were variable, from hemochromatosis to iatrogenic iron overload. Their histological stages were either portal fibrosis or cirrhosis. Inclusion bodies were ultra-structurally visualized as aggregated hemosiderins in the periportal macrophages. X-ray analysis always identified, in addition to a large amount of iron complexes including oxygen and phosphorus, a small amount of copper and sulfur in the mosaic matrixes of inclusions. There were no inclusions in the control livers. Inclusion bodies, when the liver is loaded with excess iron, may appear in the macrophages as isolated organella of aggregated hemosiderins. Trace amounts of copper-sulfur complexes were always identified in the mosaic matrices of the inclusions, suggesting cuproprotein induction against excess iron. In conclusion, inclusion formation in macrophages may be an adaptation of the liver loaded with excess iron.

Machining refractory alloys: an overview

International Nuclear Information System (INIS)

Christopher, J.D.

1984-01-01

Nontraditional machining is a generic term for those material removal processes that differ drastically from the historic operations such as turning, milling, drilling, tapping, and grinding. The use of primary energy modes other than mechanical, such as thermal, electrical, and chemical, sets these operations apart and reinforces their nontraditional label. Several of these newer processes have been very successful in machining close tolerance parts from refractory materials. This paper provides a general overview of both traditional and nontraditional aspects of machining refractory materials. 11 figures, 7 tables

Ex situ characterization of metallurgical inclusions in X100 pipeline steel before and after immersion in a neutral pH bicarbonate solution

International Nuclear Information System (INIS)

Li, Yingbo; Liu, Jie; Deng, Yida; Han, Xiaopeng; Hu, Wenbin; Zhong, Cheng

2016-01-01

The initiation of corrosion pits in pipeline steels plays an important role in the development of stress corrosion cracking. In order to reveal the effect of inclusions on corrosion initiation sites and also to clarify contradictory results from previous literature, we proposed an ex situ characterization method that is allowed to characterize exactly the same inclusion or location of the surface of steel before and after corrosion tests. The time-dependent corrosion behaviour of the inclusions and the surrounding X100 steel matrix at the same area before and after early stage immersion in a near-neutral pH bicarbonate solution was investigated by ex situ scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analysis and localized electrochemical impedance spectroscopy (LEIS). The sizes of most inclusions in X100 steel are below 3 μm. The results challenge the long-held opinion of previous work that corrosion pit initiations are related with the inclusions. It has been found that most of the inclusions remain stable (intact) during the whole testing time although severe corrosion occurs on the matrix of the steel. The chemical composition of the inclusion greatly affects the chemical stability of the inclusion. SiO_2 inclusions and complex inclusions with a high SiO_2 content remain intact although obvious general corrosion occurs on the steel matrix under the investigated immersion period. Inclusions with little Si, such as Al–Mg–Ca–O enriched inclusions, totally disappear after certain immersion time. During the immersion, the corrosion product tends to deposit at the interstice between the inclusion and steel matrix. - Highlights: • Ex situ characterization of metallurgical inclusions in X100 pipeline steel. • The pipeline steel was immersed in neutral pH bicarbonate solution. • Majority of inclusions remain stable during the whole testing time. • The chemical stability of metallurgical inclusions depends on the SiO_2 content.

Ex situ characterization of metallurgical inclusions in X100 pipeline steel before and after immersion in a neutral pH bicarbonate solution

Energy Technology Data Exchange (ETDEWEB)

Li, Yingbo; Liu, Jie [Key Laboratory of Advanced Ceramics and Machining Technology (Ministry of Education), School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Deng, Yida [Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072 (China); Han, Xiaopeng [Key Laboratory of Advanced Ceramics and Machining Technology (Ministry of Education), School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Hu, Wenbin [Key Laboratory of Advanced Ceramics and Machining Technology (Ministry of Education), School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072 (China); Zhong, Cheng, E-mail: cheng.zhong@tju.edu.cn [Key Laboratory of Advanced Ceramics and Machining Technology (Ministry of Education), School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China)

2016-07-15

The initiation of corrosion pits in pipeline steels plays an important role in the development of stress corrosion cracking. In order to reveal the effect of inclusions on corrosion initiation sites and also to clarify contradictory results from previous literature, we proposed an ex situ characterization method that is allowed to characterize exactly the same inclusion or location of the surface of steel before and after corrosion tests. The time-dependent corrosion behaviour of the inclusions and the surrounding X100 steel matrix at the same area before and after early stage immersion in a near-neutral pH bicarbonate solution was investigated by ex situ scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analysis and localized electrochemical impedance spectroscopy (LEIS). The sizes of most inclusions in X100 steel are below 3 μm. The results challenge the long-held opinion of previous work that corrosion pit initiations are related with the inclusions. It has been found that most of the inclusions remain stable (intact) during the whole testing time although severe corrosion occurs on the matrix of the steel. The chemical composition of the inclusion greatly affects the chemical stability of the inclusion. SiO{sub 2} inclusions and complex inclusions with a high SiO{sub 2} content remain intact although obvious general corrosion occurs on the steel matrix under the investigated immersion period. Inclusions with little Si, such as Al–Mg–Ca–O enriched inclusions, totally disappear after certain immersion time. During the immersion, the corrosion product tends to deposit at the interstice between the inclusion and steel matrix. - Highlights: • Ex situ characterization of metallurgical inclusions in X100 pipeline steel. • The pipeline steel was immersed in neutral pH bicarbonate solution. • Majority of inclusions remain stable during the whole testing time. • The chemical stability of metallurgical inclusions depends on the SiO{sub 2

Chemically bonded ceramic matrix composites: Densification and conversion to diffusion bonding

International Nuclear Information System (INIS)

Johnson, B.R.; Guelguen, M.A.; Kriven, W.M.

1995-01-01

Chemically bonded ceramics appear to be a promising alternative route for near-net shape fabrication of multi-phase ceramic matrix composites (CMC's). The hydraulic (and refractory) properties of fine mono-calcium aluminate (CaAl 2 O 4 ) powders were used as the chemically bonding matrix phase, while calcia stabilized zirconia powders were the second phase material. Samples containing up to 70 wt% (55 vol%) zirconia have been successfully compacted and sintered. Various processing techniques were evaluated. Processing was optimized based on material properties, dilatometry and simultaneous thermal analysis (DTA/TGA). The physical characteristics of this novel CMC were characterized by hardness, density, and fracture toughness testing. Microstructures were evaluated by SEM and phase identification was verified using XRD

Production of lightweight refractory material by hydrothermal process

International Nuclear Information System (INIS)

Sulejmani, Ramiz B.

2002-01-01

Many different processes of production of lightweight refractories are well known over the World. Traditional production of lightweight refractories is by addition of combustibles or by a special frothing process. This work is concerned with hydrothermal of lightweight refractories from rice husk ash. The rice husk ash, used in present investigations were from Kocani region, R. Macedonia. The chemical analysis of the rice husk ash shows that it contains 91,8 - 93,7% SiO 2 and some alkaline and alkaline earth oxides. Microscopic and X - ray diffraction examinations of the rice husk ash have shown that it is composed of cristobalite, tridimite and amorphous silica. The composition of the mixture for lightweight refractory brick production is 93,4% rice husk ash and 6,6% Ca(OH) 2 . The mixtures were well mixed, moistened and pressed at 5 - 10 MPa. The hydrothermal reactions between calcium hydroxide and rice husk ash over the temperature range 80 - 160 o C were investigated. The period of autoclave treatment was from 2 to 72 h. After the hydrothermal treatment of the samples, the mineralogical composition, bulk density, density, cold crushing strength, porosity, refractoriness and thermal expansion were examined. Analysing the properties of the obtained samples it can be concluded that from rice husk ash and calcium hydroxide under hydrothermal condition it is possible to obtain lightweight acid refractory material with high quality.(Author)

Directed light fabrication of refractory metals and alloys

International Nuclear Information System (INIS)

Fonseca, J.C.; Lewis, G.K.; Dickerson, P.G.; Nemec, R.B.

1999-01-01

This report covers work performed under Order No. FA0000020 AN Contract DE-AC12-76SN00052 for deposition of refractory pure metals and alloys using the Directed Light Fabrication (DLF) process and represents the progress in depositing these materials through September 1998. In extending the DLF process technology to refractory metals for producing fully dense, structurally sound deposits, several problems have become evident. 1. Control of porosity in DLF-deposited refractory metal is difficult because of gases, apparently present in commercially purchased refractory metal powder starting materials. 2. The radiant heat from the molten pool during deposition melts the DLF powder feed nozzle. 3. The high reflectivity of molten refractory metals, at the Nd-YAG laser wavelength (1.06microm), produces damaging back reflections to the optical train and fiber optic delivery system that can terminate DLF processing. 4. The current limits on the maximum available laser power to prevent back reflection damage limit the parameter range available for densification of refractory metals. The work to date concentrated on niobium, W-25Re, and spherodized tungsten. Niobium samples, made from hydride-dehydride powder, had minimal gas porosity and the deposition parameters were optimized; however, test plates were not made at this time. W-25Re samples, containing sodium and potassium from a precipitation process, were made and porosity was a problem for all samples although minimized with some process parameters. Deposits made from potassium reduced tungsten that was plasma spherodized were made with minimized porosity. Results of this work indicate that further gas analysis of starting powders and de-gassing of starting powders and/or gas removal during deposition of refractory metals is required

Spinning of refractory metals

International Nuclear Information System (INIS)

Chang Wenkua; Zheng Han

1989-01-01

The effects of spinning process parameters including max. pass percentage reduction, spinning temperature, feed rate, lubricant and annealing technology on the quality of shaped components are summarized and discussed in the present paper. The above mentioned parameters are adopted in the process of spinning of barrel-shaped and specially shaped components of refractory metals and their alloys W, Mo, Nb, Zr, TZM molybdenum alloy, C-103, C-752 niobium alloy etc. The cause of leading to usual defects of spun products of refractory metals such as lamellar as 'scaling', crack, swelling, wrinkle, etc. have been analysed and the ways to eliminate the defects have been put forward. 8 figs., 5 tabs. (Author)

Migration of TRU-containing slag into candidate refractories for waste management

International Nuclear Information System (INIS)

Seymour, W.C.

1978-11-01

Results of initial tests on transuranic migration into commercial refractories are reported. Five castable refractories and a plastic-bonded refractory were tested using the cup test method. Initial results indicate that castable materials will not survive conditions expected in the slagging pyrolysis unit; plastic refractories appear to have better performance. The major mechanism of migration into the tested refractories is pore penetration. Al 2 O 3 and Al 2 O 3 -Cr 2 O 3 phases appear resistant to chemical diffusion of transuranics. 2 figures, 16 tables

Small lead and indium inclusions in aluminium

International Nuclear Information System (INIS)

Johnson, E.; Hjemsted, K.; Schmidt, B.; Bourdelle, K.K.; Johansen, A.; Andersen, H.H.; Sarholt-Kristensen, L.

1992-01-01

This paper reports implantation of lead or indium into aluminum results in spontaneous phase separation and formation of lead or indium precipitates. The precipitates grow in topotactical alignment with the matrix, giving TEM images characterized by moire fringes. The size and density of the precipitates increase with increasing fluence until coalescence begins to occur. Implantation at elevated temperatures lead to formation of large precipitates with well developed facets. This is particularly significant for implantation above the bulk melting point of the implanted species. Melting and solidification have been followed by in-situ TEM heating and cooling experiments. Superheating up to ∼50 K above the bulk melting point has been observed, and the largest inclusions melt first. Melting is associated with only partial loss of facetting of the largest inclusion. Initial growth of the inclusions occurs by trapping of atoms retained in supersaturated solution. Further growth occurs by coalescence of neighboring inclusion in the liquid phase. Solidification is accompanied by a strong undercooling ∼30 K below the bulk melting point, where the smallest inclusions solidify first. Solidification is characterized by spontaneous restoration of the facets and the topotactical alignment

Volatile and light lithophile elements in high-anorthite plagioclase-hosted melt inclusions from Iceland

Science.gov (United States)

Neave, David A.; Hartley, Margaret E.; Maclennan, John; Edmonds, Marie; Thordarson, Thorvaldur

2017-05-01

Melt inclusions formed during the early stages of magmatic evolution trap primitive melt compositions and enable the volatile contents of primary melts and the mantle to be estimated. However, the syn- and post-entrapment behaviour of volatiles in primitive high-anorthite plagioclase-hosted melt inclusions from oceanic basalts remains poorly constrained. To address this deficit, we present volatile and light lithophile element analyses from a well-characterised suite of nine matrix glasses and 102 melt inclusions from the 10 ka Grímsvötn tephra series (i.e., Saksunarvatn ash) of Iceland's Eastern Volcanic Zone (EVZ). High matrix glass H2O and S contents indicate that eruption-related exsolution was arrested by quenching in a phreatomagmatic setting; Li, B, F and Cl did not exsolve during eruption. The almost uniformly low CO2 content of plagioclase-hosted melt inclusions cannot be explained by either shallow entrapment or the sequestration of CO2 into shrinkage bubbles, suggesting that inclusion CO2 contents were controlled by decrepitation instead. High H2O/Ce values in primitive plagioclase-hosted inclusions (182-823) generally exceed values expected for EVZ primary melts (∼ 180), and can be accounted for by diffusive H2O gain following the entrainment of primitive macrocrysts into evolved and H2O-rich melts a few days before eruption. A strong positive correlation between H2O and Li in plagioclase-hosted inclusions suggests that diffusive Li gain may also have occurred. Extreme F enrichments in primitive plagioclase-hosted inclusions (F/Nd = 51-216 versus ∼15 in matrix glasses) possibly reflect the entrapment of inclusions from high-Al/(Al + Si) melt pools formed by dissolution-crystallisation processes (as indicated by HFSE depletions in some inclusions), and into which F was concentrated by uphill diffusion since F is highly soluble in Al-rich melts. The high S/Dy of primitive inclusions (∼300) indicates that primary melts were S-rich in comparison

Refractory of Furnaces to Reduce Environmental Impact

International Nuclear Information System (INIS)

Hanzawa, Shigeru

2011-01-01

The energy load of furnaces used in the manufacturing process of ceramics is quite large. Most of the environmental impact of ceramics manufacturing is due to the CO 2 produced from this high energy load. To improve this situation, R and D has focused on furnace systems and techniques of control in order to reduce energy load. Since furnaces are comprised of refractory, consideration of their mechanical and thermal characteristics is important. Herein are described several refractory types which were chosen through comparison of the characteristics which contribute to heat capacity reduction, heat insulating reinforcement and high emissivity, thereby improving thermal radiation heat transfer efficiency to the ceramic articles. One selected refractory material which will reduce the environmental impact of a furnace, chosen considering low heat capacity and high emissivity characteristics, is SiC. In this study, thermal radiation heat transfer efficiency improvement and its effect on ceramic articles in the furnace and oxidation behaviour were investigated at 1700K. A high density SiC refractory, built into the furnace at construction, has relatively high oxidation durability and has the ability to reduce environmental impact-CO 2 by 10 percent by decreasing the furnace's energy load. However, new oxidation prevention techniques for SiC will be necessary for long-term use in industrial furnaces, because passive to active oxidation transition behaviour of commercial SiC refractory is coming to close ideal.

Refractory of Furnaces to Reduce Environmental Impact

Science.gov (United States)

Hanzawa, Shigeru

2011-10-01

The energy load of furnaces used in the manufacturing process of ceramics is quite large. Most of the environmental impact of ceramics manufacturing is due to the CO2 produced from this high energy load. To improve this situation, R&D has focused on furnace systems and techniques of control in order to reduce energy load. Since furnaces are comprised of refractory, consideration of their mechanical and thermal characteristics is important. Herein are described several refractory types which were chosen through comparison of the characteristics which contribute to heat capacity reduction, heat insulating reinforcement and high emissivity, thereby improving thermal radiation heat transfer efficiency to the ceramic articles. One selected refractory material which will reduce the environmental impact of a furnace, chosen considering low heat capacity and high emissivity characteristics, is SiC. In this study, thermal radiation heat transfer efficiency improvement and its effect on ceramic articles in the furnace and oxidation behaviour were investigated at 1700K. A high density SiC refractory, built into the furnace at construction, has relatively high oxidation durability and has the ability to reduce environmental impact-CO2 by 10 percent by decreasing the furnace's energy load. However, new oxidation prevention techniques for SiC will be necessary for long-term use in industrial furnaces, because passive to active oxidation transition behaviour of commercial SiC refractory is coming to close ideal.

Development of alumino-silicate refractories in Ghana

International Nuclear Information System (INIS)

Kisiedu, A. K.; Tetteh, D.M.B.; Obiri, H. A.; Brenya, E. F.; Ayensu, A.

2008-01-01

Alumino-silicate (bauxite), andalusite, kaolin and clay were investigated for suitability in production of alumina, mullite and fireclay brick refractories. The raw materials were characterized by X-ray diffraction, differential thermal and silicate analyses. The x-ray diffraction analysis of alumina and mullite refractories fired at 1450 0 C, and fireclay bricks fired at 1350 0 C, indicated presence of corundum and alpha-alumina crystals. The values of thermal (fired) shrinkage, crushing, strength, porosity, water absorption and bulk density determined were 31.1%, 2.3 x 10 3 kg/m 3 , 4.86 x 10 6 N/m 2 and 13.2 % for mullite; 30.2%, 2.4 x 10 3 kg/m 3 , 3.20 x 10 6 N/m 2 and W = 12.8 % for alumina; and 25.2 %, 2.1 x 10 3 kg/m 3 , 2.61 x 10 6 N/m 2 and W = 11.8% for fireclay, respectively. Bauxite, andalusite and special kaolin were identified as potential raw materials for developing alumina and mullite refractories for construction of high temperature kilns and furnaces operating at 1350 0 C. The clay and kaolin minerals could be used to produce fireclay refractories for construction of incinerators operating at maximum temperatures of about 1000 0 C. The performance of the refractories was demonstrated by producing bricks to construct kilns and incinerators for the ceramic industry and hospitals. (au)

Biomolecules in the treatment of lichen planus refractory to corticosteroid therapy: Clinical and histopathological assessment.

Science.gov (United States)

Piñas, Laura; Alkhraisat, Mohammad Hamdan; Suárez-Fernández, Ricardo; Anitua, Eduardo

2018-03-01

Local deficit of several biomolecules have been described in oral lichen planus (OLP). Such a deficit impairs cellular functions and cell-matrix communication. Assess the efficacy of the local application of autologous biomolecules in the treatment of erosive OLP. In this study, the use of plasma rich in growth factors (PRGF) as a source of blood-derived and autologous growth factors and proteins were tested in erosive oral lichen planus refractory to corticosteroids. Histopathological features of the disease were also analysed at the time of diagnosis. Clinical data were the number of recurrences and achievement of pain reduction and complete healing of the lesions. A total of 10 patients with erosive OLP refractory to treatment by corticosteroids were included in the study. All patients were females with a mean age of 48±12years. A complete remission of the disease was achieved after one infiltration of PRGF in 8 patients. Only 2 patients required a total of 2 infiltrations to heal. Hydropic degeneration of the epithelium basal layer, band-like subepithelial lymphocytic infiltration and fibrin deposits in the epithelium were observed in all patients. Interestingly plasma cells were present in 2 patients. All patients presenting plasma cells healed after only one PRGF infiltration. However, 2 patients out of 6 (no plasma cells) required 2 infiltrations. The local administration of autologous local factors could overcome the deficit of biomolecular clues and thus improve cell functions and restore cell-matrix communication. Copyright © 2017 Elsevier GmbH. All rights reserved.

Calculation of electromagnetic constitutive parameters of insulating magnetic materials with conducting inclusions

Energy Technology Data Exchange (ETDEWEB)

Kuster, E.; Moore, R.; Lust, L.; Kemper, P. [Georgia Inst. of Tech., Atlanta, GA (United States)

1996-12-31

A Method of Moments (MoM) electromagnetic model of percolating conducting films was applied to calculate the effective parameters of the composite formed by conducting inclusions placed within a dispersive magnetic but nondispersive dielectric matrix. The MoM calculations demonstrate a coupling between the magnetic properties of the matrix and the effective composite permittivity and frequency dispersion of the composite. The coupling of permittivity and permeability is observed near the percolation threshold of the composite and for high conductivity inclusions. The prediction agrees with physical expectations since near percolation the conduction correlation length dominates the effective permittivity of the composite and this correlation length is determined by both the permittivity and permeability of the composite.

Refractory disease in antineutrophil cytoplasmic antibodies associated vasculitis

NARCIS (Netherlands)

Rutgers, Abraham; Kallenberg, Cornelis

Purpose of review Induction treatment of antineutrophil cytoplasmic antibodies (ANCA) associated vasculitis (AAV) is not always successful and nonresponding patients are considered refractory. Recent findings Refractory disease should be subdefined to the treatment that was received.

Correlated thermal motion of two liquid Pb inclusions attached to a fixed dislocation in an Al matrix

DEFF Research Database (Denmark)

Prokofjev, Sergei I.; Johnson, Erik

2017-01-01

of the inclusions on the dislocation line occurs as a result of their mutual repulsion and their repulsion from the fixed ends of the dislocation caused by the dislocation line tension. The oscillations of the inclusions can be considered as correlated thermal motion in coupled potential wells. The effective...... potentials, in which the inclusions move, and the effective potential of their interactions are evaluated. It is found that the spatial correlations of the positions of the inclusions on the dislocation depend strongly on the interaction potential. The observed correlations of the positions of the inclusions...

Studies of permittivity and permeability of dielectric matrix with cuboid metallic inclusions in different orientations

Directory of Open Access Journals (Sweden)

W. M. Wu

2014-10-01

Full Text Available In this paper, we investigate the possibility of using the heterogeneous materials, with cuboid metallic inclusions inside a dielectric substrate (host to control the effective permittivity. We find that in the gigahertz range, such a material demonstrates a significantly larger permittivity compared to the pure dielectric substrate. Three principal orientations of microscale cuboid inclusions have been taken into account in this study. The highest permittivity is observed when the orientation provides the largest polarization (electric dipole moment. The detrimental side effect of the metallic inclusion, which leads to the decrease of the effective magnetic permeability, can be suppressed by the proper choice of shape and orientation of the inclusions. This choice can in fact reduce the induced current and hence maximize the permeability. The dissipative losses are shown to be negligible in the relevant range of frequencies and cuboid dimensions.

Diagnosis and management of refractory celiac disease: a systematic review.

Science.gov (United States)

Labidi, Asma; Serghini, Meriem; Karoui, Sami; Boubaker, Jalel; Filali, Azza

2013-01-01

Refractory celiac disease is defined by persisting malabsorptive symptoms in spite of a strict gluten free diet for at least 6 to 12 months. Alternatives to gluten free diet seem to be still controversial. To describe the clinical and epidemiologic aspects of refractory celiac disease, and to identify therapeutic options in this condition. Systematic review and critical analysis of observational studies, clinical trials and case reports that focused on diagnosis and management of refractory celiac disease. Refractory celiac disease can be classified as type 1 or type 2 according to the phenotype of intraepithelial lymphocytes. Great complications such as enteropathy-associated T-cell lymphoma may occur in a subgroup of these patients mainly in refractory celiac disease type 2. Curative therapies are still lacking. Refractory celiac disease remains a diagnosis of exclusion. Its prognosis remains still dismal by the absence yet of curative therapies. However, some new treatments seem to hold promise during few cohort-studies.

Modern materials based on refractory compounds

International Nuclear Information System (INIS)

Kosolapova, T.Ya.

1979-01-01

Discussed are the existing methods for synthesizing powders of binary refractory compounds and high-productivity techniques which hold promise as regards the manufacture of highly disperse and pure powders. Plasmochemical synthesis is shown to be an effective method for obtaining practically all carbides, nitrides and borides. A description is given of three main methods for obtaining single crystals of refractory compounds (TiN, TiC, ZrC, ZrB 2 , NbC) fairly perfect in structure and composition. These processes include deposition from vapour-gas phase, melting in arc plasma and crystallization from solutions in metallic melts. The advantages have been shown of the self-propagating high-temperature synthesis of refractory compounds, ensuring the manufacture of products, close in composition to stoichiometric ones simultaneously with forming of items. Mechanical, thermal, abrasive, and resistive characteristics of the above materials are presented

In-situ development of carbon nanotubes network and graphitic carbon by catalytic modification of phenolic resin binder in Al2O3–MgO–C refractories

Directory of Open Access Journals (Sweden)

Atul V. Maldhure

2017-09-01

Full Text Available In-situ formation of cross-linked carbon nanotubes network reinforced the refractory matrix and helps to improve the mechanical properties at elevated temperature. In this paper, the effect of modified phenol-formaldehyde (PF resin binder on the various mechanical properties of alumina–magnesia–carbon (AMC refractories was investigated. Initially, PF resin was modified by adding a different proportion of nickel catalyst. The AMC specimens (with the 7% carbon were prepared by using 5% of modified PF resin. The pressed samples were cured at 180 °C for 24 h and characterized by XRD, Raman spectroscopy, and FE-SEM. The characterisation shows that, in-situ formation of graphitic carbon and carbon nanotubes network in the specimens due to modification of PF resin. In-situ formation of phases leads to enhancement of density and mechanical properties of refractory at elevated temperature due to the reinforcing effect.

Alumina-zirconium ceramics synthesis by selective laser sintering/melting

International Nuclear Information System (INIS)

Shishkovsky, I.; Yadroitsev, I.; Bertrand, Ph.; Smurov, I.

2007-01-01

In the present paper, porous refractory ceramics synthesized by selective laser sintering/melting from a mixture of zirconium dioxide, aluminum and/or alumina powders are subjected to optical metallography and X-ray analysis to study their microstructure and phase composition depending on the laser processing parameters. It is shown that high-speed laser sintering in air yields ceramics with dense structure and a uniform distribution of the stabilizing phases. The obtained ceramic-matrix composites may be used as thermal and electrical insulators and wear resistant coating in solid oxide fuel cells, crucibles, heating elements, medical tools. The possibility to reinforce refractory ceramics by laser synthesis is shown on the example of tetragonal dioxide of zirconium with hardened micro-inclusion of Al 2 O 3 . By applying finely dispersed Y 2 O 3 powder inclusions, the type of the ceramic structure is significantly changed

Influence of nano-inclusions' grain boundaries on crack propagation modes in materials

International Nuclear Information System (INIS)

Karakasidis, T.E.; Charitidis, C.A.

2011-01-01

The effect of nano-inclusions on materials' strength and toughness has attracted great interest in recent years. It has been shown that tuning the morphological and microstructural features of materials can tailor their fracture modes. The existence of a characteristic size of inclusions that favours the fracture mode (i.e. transgranular or intergranular) has been experimentally observed but also predicted by a 2D model based on energetic arguments which relates the crack propagation mode to the ratio of the interface area between the crystalline inclusion and the matrix with the area of the crystallite inclusion in a previous work. In the present work, a 3D model is proposed in order to extend the 2D model and take into account the influence of the size of grain boundary zone on the toughening/hardening behavior of the material as it was observed experimentally in the literature. The model relates crack propagation mode to the ratio of the volume of the grain boundary zone between the crystalline inclusion and the matrix with the volume of the nano-inclusion. For a ratio below a critical value, transgranular propagation is favoured while for larger values, intergranular propagation is favoured. We also demonstrate that the extent of the grain boundary region also can significantly affect this critical value. The results of the model are in agreement with the literature experimental observations related to the toughening/hardening behavior as a function of the size of crystalline inclusions as well as the width of the grain boundary regions.

Structure, preparation and properties of refractory compounds and systems

International Nuclear Information System (INIS)

Holleck, H.; Thuemmler, F.

1977-01-01

At the beginning of this report the possibilities of hardness optimization of refractory carbides are generally discussed. Three papers deal with TaC-basis refractories and hard metals. In particular, carbides with very low nonmetal/metal ratios and composites with hard phases formed by decomposition of tantalum carbonitrides are discussed. Another contribution reports investigations concerning the influence of the microstructure on the hardness of polycristaline mixed carbides. In a series of four papers, results are presented on the work of optimization conventional WC hard metals by introduction of a Fe,Co,Ni-binder: The influence of composition, carbon content and sintering conditions, as well as the wetting behaviour between carbides and binder metals are discussed. Phase relations in the refractory nitride and refractory nitride-binder metal systems as well as phase stabilities of ordered transition metal phases are reported in three papers, fundamental in character. Finally, the work concerning chemical analysis of refractory systems is described. (orig.) [de

VEGF 165 Gene Therapy for Patients with Refractory Angina: Mobilization of Endothelial Progenitor Cells

International Nuclear Information System (INIS)

Rodrigues, Clarissa G.; Plentz, Rodrigo D.M.; Dipp, Thiago; Salles, Felipe B.; Giusti, Imarilde I.; Sant'Anna, Roberto T.; Eibel, Bruna; Nesralla, Ivo A.; Markoski, Melissa; Beyer, Nance N.; Kalil, Renato A. K.

2013-01-01

Vascular endothelial growth factor (VEGF) induces mobilization of endothelial progenitor cells (EPCs) with the capacity for proliferation and differentiation into mature endothelial cells, thus contributing to the angiogenic process. We sought to assess the behavior of EPCs in patients with ischemic heart disease and refractory angina who received an intramyocardial injections of 2000 µg of VEGF 165 as the sole therapy. The study was a subanalysis of a clinical trial. Patients with advanced ischemic heart disease and refractory angina were assessed for eligibility. Inclusion criteria were as follows: signs and symptoms of angina and/or heart failure despite maximum medical treatment and a myocardial ischemic area of at least 5% as assessed by single-photon emission computed tomography (SPECT). Exclusion criteria were as follows: age > 65 years, left ventricular ejection fraction < 25%, and a diagnosis of cancer. Patients whose EPC levels were assessed were included. The intervention was 2000 µg of VEGF 165 plasmid injected into the ischemic myocardium. The frequency of CD34+/KDR+ cells was analyzed by flow cytometry before and 3, 9, and 27 days after the intervention. A total of 9 patients were included, 8 males, mean age 59.4 years, mean left ventricular ejection fraction of 59.3% and predominant class III angina. The number of EPCs on day 3 was significantly higher than that at baseline (p = 0.03); however, that on days 9 th and 27 th was comparable to that at baseline. We identified a transient mobilization of EPCs, which peaked on the 3th day after VEGF 165 gene therapy in patients with refractory angina and returned to near baseline levels on 9 th and 27 th days

Calcium and titanium isotopes in refractory inclusions from CM, CO, and CR chondrites

Science.gov (United States)

Kööp, Levke; Davis, Andrew M.; Krot, Alexander N.; Nagashima, Kazuhide; Simon, Steven B.

2018-05-01

Previous studies have shown that CV and CM chondrites incorporated Ca, Al-rich inclusions (CAIs) with different isotopic characteristics, which may represent different snapshots in the isotopic evolution of the early Solar System. To better understand how the isotopic characteristics of CAIs vary between different chondrite groups, we have studied calcium and titanium isotopes in CAIs from CM, CO, and CR chondrites. We show that all three chondrite groups contain CAIs with large anomalies in 48Ca and/or 50Ti (10s of ‰ or 100s of ε-units) as well as CAIs with no anomalies resolved beyond measurement uncertainties. Isotopically, the anomalous CO and CR chondrite CAIs resemble the platy hibonite crystals (PLACs) from CM chondrites, but they are more mineralogically complex. The new data are consistent with the well-established mutual exclusivity relationship between incorporation of 26Al and the presence of large anomalies in 48Ca and 50Ti. The two highly anomalous CO chondrite CAIs have correlated anomalies in 46Ti and 50Ti, while most other highly anomalous CAIs do not. This result could indicate that the reservoir with coupled 46Ti and 50Ti that was sampled by bulk meteorites and CV chondrite CAIs already existed before arrival and/or homogeneous distribution of 26Al in the protoplanetary disk. Among the studied CM chondrite CAIs are ten spinel-hibonite inclusions (SHIBs) with known oxygen isotopic compositions. Our results show that these objects sampled a reservoir that was well-mixed in oxygen, calcium, and titanium isotopes. We further show that SHIBs tend to be slightly enriched in the heavy calcium isotopes, suggesting that their formation history was different from CV chondrite CAIs.

Refractory versus resistant hypertension: Novel distinctive phenotypes

Science.gov (United States)

Dudenbostel, Tanja; Siddiqui, Mohammed; Gharpure, Nitin; Calhoun, David A.

2017-01-01

Resistant hypertension (RHTN) is relatively common with an estimated prevalence of 10-20% of treated hypertensive patients. It is defined as blood pressure (BP) >140/90 mmHg treated with ≥3 antihypertensive medications, including a diuretic, if tolerated. Refractory hypertension is a novel phenotype of severe antihypertensive treatment failure. The proposed definition for refractory hypertension, i.e. BP >140/90 mmHg with use of ≥5 different antihypertensive medications, including a diuretic and a mineralocorticoid receptor antagonist (MRA) has been applied inconsistently. In comparison to RHTN, refractory hypertension seems to be less prevalent than RHTN. This review focuses on current knowledge about this novel phenotype compared with RHTN including definition, prevalence, mechanisms, characteristics and comorbidities, including cardiovascular risk. In patients with RHTN excess fluid retention is thought to be a common mechanism for the development of RHTN. Recently, evidence has emerged suggesting that refractory hypertension may be more of neurogenic etiology due to increased sympathetic activity as opposed to excess fluid retention. Treatment recommendations for RHTN are generally based on use and intensification of diuretic therapy, especially with the combination of a long-acting thiazide-like diuretic and an MRA. Based on findings from available studies, such an approach does not seem to be a successful strategy to control BP in patients with refractory hypertension and effective sympathetic inhibition in such patients, either with medications and/or device based approaches may be needed. PMID:29034321

Forming Refractory Insulation On Copper Wire

Science.gov (United States)

Setlock, J.; Roberts, G.

1995-01-01

Alternative insulating process forms flexible coat of uncured refractory insulating material on copper wire. Coated wire formed into coil or other complex shape. Wire-coating apparatus forms "green" coat on copper wire. After wire coiled, heating converts "green" coat to refractory electrical insulator. When cured to final brittle form, insulating material withstands temperatures above melting temperature of wire. Process used to make coils for motors, solenoids, and other electrical devices to be operated at high temperatures.

High-dose chemotherapy and auto-SCT for relapsed and refractory Hodgkin's lymphoma patients refractory to first-line salvage chemotherapy but responsive to second-line salvage chemotherapy.

Science.gov (United States)

Rauf, Muhammad Shahzad; Maghfoor, Irfan; Elhassan, Tusneem Ahmed M; Akhtar, Saad

2015-01-01

Relapsed or primary refractory Hodgkin's lymphoma (HL) patients refractory to first-line salvage chemotherapy (first salvage) and unable to undergo high-dose chemotherapy (HDC) and autologous stem cell transplant (auto-SCT) have very poor outcome. Some patients are offered second-line salvage chemotherapy (second salvage), if they are responsive and may receive HDC auto-SCT. We identified 31 patients (18 males, 13 females) from 1996-2012 who received second salvage prior to auto-SCT. Median age at auto-SCT is 22 years. Patients were grouped as (1) relapsed-refractory (Rel:Ref): patients with prior complete response (CR) and on relapse found refractory to first salvage and received second salvage and (2) refractory-refractory (Ref:Ref): patients refractory to both primary treatment and first salvage and received second salvage. Median follow-up is 63 months (18-170). Disease status after second salvage prior to HDC was CR 16 %, partial response (PR) 71 % and stable disease 13 %. After HDC auto-SCT, CR:PR: progressive disease was observed in 18 (58 %): four (12 %): nine (29 %) patients, respectively. Five-year overall survival (OS) for whole group is 57 % (Rel:Ref vs. Ref:Ref, 73 % vs. 48 %, p = 0.48). Progression-free survival (PFS) for whole group is 52 % (Rel:Ref vs. Ref:Ref, 73 % vs. 40 % respectively, p = 0.11). Second-line salvage is a valid approach with no long-term side effects for those HL patients who do not respond to first-line salvage chemotherapy and they can be candidate of HDC and stem cell transplant with a high ORR, the PFS and OS in relapse-refractory and refractory-refractory group of patients.

Neutrino Mass Matrix Textures: A Data-driven Approach

CERN Document Server

Bertuzzo, E; Machado, P A N

2013-01-01

We analyze the neutrino mass matrix entries and their correlations in a probabilistic fashion, constructing probability distribution functions using the latest results from neutrino oscillation fits. Two cases are considered: the standard three neutrino scenario as well as the inclusion of a new sterile neutrino that potentially explains the reactor and gallium anomalies. We discuss the current limits and future perspectives on the mass matrix elements that can be useful for model building.

Refractory myasthenia gravis - clinical profile, comorbidities and response to rituximab.

Science.gov (United States)

Sudulagunta, Sreenivasa Rao; Sepehrar, Mona; Sodalagunta, Mahesh Babu; Settikere Nataraju, Aravinda; Bangalore Raja, Shiva Kumar; Sathyanarayana, Deepak; Gummadi, Siddharth; Burra, Hemanth Kumar

2016-01-01

Introduction: Myasthenia gravis (MG) is an antibody mediated autoimmune neuromuscular disorder characterized by fatigable muscle weakness. A proportion of myasthenia gravis patients are classified as refractory due to non responsiveness to conventional treatment. This retrospective study was done to evaluate clinical profile, epidemiological, laboratory, and features of patients with MG and mode of management using rituximab and complications. Methods: Data of myasthenia gravis patients admitted or presented to outpatient department (previous medical records) with MG between January 2008 and January 2016 were included. A total of 512 patients fulfilled the clinical and diagnostic criteria of myasthenia gravis of which 76 patients met the diagnostic certainty for refractory myasthenia gravis and were evaluated. Results: Out of 76 refractory MG patients, 53 (69.73%) patients fulfilled all the three defined criteria. The median age of onset of the refractory MG group was 36 years with a range of 27-53 years. In our study 25 patients (32.89%) belonged to the age group of 21-30 years. Anti-MuSK antibodies were positive in 8 non-refractory MG patients (2.06%) and 36 refractory MG patients (47.36%). Mean HbA 1C was found to be 8.6±2.33. The dose of administered prednisone decreased by a mean of 59.7% ( p =3.3x10 -8 ) to 94.6% ( p =2.2x10 -14 ) after the third cycle of rituximab treatment. Conclusion: The refractory MG patients are most commonly female with an early age of onset, anti-MuSK antibodies, and thymomas. Refractory MG patients have higher prevalence and poor control (HbA 1C >8%) of diabetes mellitus and dyslipidemia probably due to increased steroid usage. Rituximab is very efficient in treatment of refractory MG with adverse effects being low.

RESULTS OF OUTPATIENT PROGRAM ON EFFECTIVE THERAPY OF REFRACTORY ARTERIAL HYPERTENSION

Directory of Open Access Journals (Sweden)

M. M. Batyushin

2015-12-01

Full Text Available Aim. To increase in efficacy of antihypertensive therapy in patients with refractory arterial hypertension (HT.Material and methods. Patients with refractory HT were revealed during first month of program. The causes of refractory HT were analyzed. Combined antihypertensive therapy was prescribed to reach target level of blood pressure (BP. This therapy lasted 24 weeks and included angiotensin converting enzyme (ACE inhibitor, thiazid diuretic (indapamide and dihydropyridine calcium antagonist (nifedipine XL.Results. 200 patients with refractory HT were revealed. True refractory HT took place in 59,9% of patients and pseudo refractory HT – in 40,1% of patients. Lack of diuretics or combined antihypertensive therapy were the main reason of insufficient BP control. Proposed 3-drugs therapy resulted in reduction of systolic BP from 190 to 132 Hg mm and diastolic BP from 104 to 81 Hg mm. Target level of BP was reached in 94% patients. There were no side effects which demanded to stop therapy.Conclusion. High incidence of pseudorefractory HT (40,1% is revealed. Significant prevalence of renal disturbances especially chronic interstitial inflammatory could be responsible for refractory HT development. Use of 3-drugs therapy (ACE inhibitor, indapamide and nifedipine XL provides effective control of BP in refractory and pseudorefractory HT.

RESULTS OF OUTPATIENT PROGRAM ON EFFECTIVE THERAPY OF REFRACTORY ARTERIAL HYPERTENSION

Directory of Open Access Journals (Sweden)

M. M. Batyushin

2007-01-01

Full Text Available Aim. To increase in efficacy of antihypertensive therapy in patients with refractory arterial hypertension (HT.Material and methods. Patients with refractory HT were revealed during first month of program. The causes of refractory HT were analyzed. Combined antihypertensive therapy was prescribed to reach target level of blood pressure (BP. This therapy lasted 24 weeks and included angiotensin converting enzyme (ACE inhibitor, thiazid diuretic (indapamide and dihydropyridine calcium antagonist (nifedipine XL.Results. 200 patients with refractory HT were revealed. True refractory HT took place in 59,9% of patients and pseudo refractory HT – in 40,1% of patients. Lack of diuretics or combined antihypertensive therapy were the main reason of insufficient BP control. Proposed 3-drugs therapy resulted in reduction of systolic BP from 190 to 132 Hg mm and diastolic BP from 104 to 81 Hg mm. Target level of BP was reached in 94% patients. There were no side effects which demanded to stop therapy.Conclusion. High incidence of pseudorefractory HT (40,1% is revealed. Significant prevalence of renal disturbances especially chronic interstitial inflammatory could be responsible for refractory HT development. Use of 3-drugs therapy (ACE inhibitor, indapamide and nifedipine XL provides effective control of BP in refractory and pseudorefractory HT.

Bone marrow immunophenotyping by flow cytometry in refractory cytopenia of childhood

NARCIS (Netherlands)

A.M. Aalbers (Anna Maartje); M.M. van den Heuvel-Eibrink (Marry); I. Baumann (Irith); M.N. Dworzak (Michael); H. Hasle (Henrik); F. Locatelli (Franco); B. de Moerloose (Barbara); M. Schmugge; E. Mejstříková (Ester); M. Nováková (Michaela); M. Zecca (Marco); C.M. Zwaan (Christian Michel); J.G. te Marvelde (Jeroen); A.W. Langerak (Anton); J.J.M. van Dongen (Jacques); R. Pieters (Rob); C.M. Niemeyer (Charlotte); V.H.J. van der Velden (Vincent)

2015-01-01

textabstractRefractory cytopenia of childhood is the most common type of childhood myelodysplastic syndrome. Because the majority of children with refractory cytopenia have a normal karyotype and a hypocellular bone marrow, differentiating refractory cytopenia from the immune-mediated bone marrow

Colectomy for refractory constipation

DEFF Research Database (Denmark)

Raahave, Dennis; Loud, Franck Bjørn; Christensen, Elsebeth

2010-01-01

OBJECTIVE: This study evaluated the type of colectomy, postoperative complications, functional results, and satisfaction in patients with constipation refractory to conservative therapy. Further, colonic transit time (CTT), faecal load (coprostasis), and colon length (redundancies) were compared ...

Below-surface analysis of inclusions with PIXE and PIGE

International Nuclear Information System (INIS)

MacArthur, J.D.; Ma, X.P.; Palmer, G.R.; Anderson, A.J.; Clark, A.H.

1990-01-01

The composition of fluid inclusions in host minerals holds much information about the chemical environment of mineral formation. When solid inclusions are exposed through polishing, their content can readily be investigated with an electron or proton probe. However, with an electron probe, only the daughter minerals or the residue material left when a fluid inclusion is opened can be analyzed since electrons with energies of tens of keV cannot penetrate to the unexposed inclusion. On the other hand, proton beams of a few MeV can penetrate a few tens of μm of material and still be able to excite characteristic radiation. This phenomenon has been exploited for the analysis of subsurface inclusions. Ideally, standard petrographic sections are polished to that inclusions, targetted for analysis, are brought to within 10 μm of the surface. The overlying matrix reduces the sensitivity of PIXE for the elements of low Z such as Na and Al because of the attenuation of the X-rays. However, these elements, as well as elements of even lower Z, which cannot be analyzed with the electron probe, can readily be detected with PIGE at good sensitivity. (orig.)

Statistical experimental design for refractory coatings

International Nuclear Information System (INIS)

McKinnon, J.A.; Standard, O.C.

2000-01-01

The production of refractory coatings on metal casting moulds is critically dependent on the development of suitable rheological characteristics, such as viscosity and thixotropy, in the initial coating slurry. In this paper, the basic concepts of mixture design and analysis are applied to the formulation of a refractory coating, with illustration by a worked example. Experimental data of coating viscosity versus composition are fitted to a statistical model to obtain a reliable method of predicting the optimal formulation of the coating. Copyright (2000) The Australian Ceramic Society

Typical corrosion of alumina refractory in aluminum reflow oven

International Nuclear Information System (INIS)

Baldo, Jaoa B.

2014-01-01

The refractory linings of furnaces for secondary melting of aluminum, are exposed to intense attack by the molten metal. This occurs, because molten aluminum has a strong reducing power over the refractory oxide components, particularly Fe 2 O 3 , SiO 2 and TiO 2 . In this work, based on X-ray diffraction and scanning electron microscopy, it is presented a post mortem study of the mechanisms that lead to a premature wear of a 80% Al2O3 chemically bonded refractory bricks, used in the metal line of an aluminum re-melting furnace. The SEM analysis demonstrated that the oxides SiO 2 and TiO 2 contained in the refractory were reduced and transformed into their metallic elements causing an intense structural spalling. (author)

Beta-blockers in cirrhosis and refractory ascites

DEFF Research Database (Denmark)

Kimer, Nina; Feineis, Martin; Møller, Søren

2015-01-01

OBJECTIVE: It is currently discussed if beta-blockers exert harmful effects and increase mortality in patients with cirrhosis and refractory ascites. In this study, we provide an overview of the available literature in this field in combination with a retrospective analysis of 61 patients...... trials (9 trials on propranolol, 1 case-control study and 4 retrospective analyses) were identified. One trial suggested an increased mortality in patients treated with beta-blockers and refractory ascites. The results of the remaining trials were inconclusive. No increase in mortality among beta-blocker......-treated patients was found in the present retrospective analysis. CONCLUSIONS: Treatment with beta-blockers may increase mortality in patients with cirrhosis and refractory ascites. However, the current evidence is sparse and high-quality studies are warranted to clarify the matter....

Fire and explosion hazards of refractory compound powders

International Nuclear Information System (INIS)

Krivtsov, V.A.; Kostina, E.S.

1978-01-01

Data on fire and explosion hazards of refractory compound powders (HfC, ZrC,LaB 6 , ZrN, etc.) are presented. It is shown that refractory compounds can be fire- and exposion hazardous in various degrees. Qualitative and quantitative estimations of one of fire-hazard characteristics - smoldering temperature - are presented

Improvements on heap leaching process for a refractory uranium ore and yellow cake precipitation process

International Nuclear Information System (INIS)

Feng Jianke

2013-01-01

Some problems such as formed harden matrix, ore heap compaction, poor permeability, and agglomeration of absorption resin occur during extracting uranium from a refractory uranium ore by heap leaching process. After some measures were taken, i.e. spraying a new ore heap by low concentration acid, two or more ore heaps in series leaching, turning ores in ore heap, the permeability was improved, acid consumption was reduced. Through precipitate circulation and aging, the yellow cake slurry in amorphous or microlite form was transformed to crystal precipitate, thus uranium content in yellow cake was improved, and water content in yellow cake was lowered with good economic benefits. (author)

Refractory episodic vertigo: role of intratympanic gentamicin and vestibular evoked myogenic potentials,

Directory of Open Access Journals (Sweden)

Erika Celis-Aguilar

Full Text Available Abstract Introduction: Even today, the treatment of intractable vertigo remains a challenge. Vestibular ablation with intratympanic gentamicin stands as a good alternative in the management of refractory vertigo patients. Objective: To control intractable vertigo through complete saccular and horizontal canal vestibular ablation with intratympanic gentamicin treatment. Methods: Patients with refractory episodic vertigo were included. The inclusion criteria were: unilateral ear disease, moderate to profound sensorineural hearing loss, and failure to other treatments. Included patients underwent 0.5-0.8 mL of gentamicin intratympanic application at a 30 mg/mL concentration. Vestibular ablation was confirmed by the absence of response on cervical vestibular evoked myogenic potentials and no response on caloric tests. Audiometry, electronystagmography with iced water, and vestibular evoked myogenic potentials were performed in all patients. Results: Ten patients were included; nine patients with Meniere's disease and one patient with (late onset delayed hydrops. Nine patients showed an absent response on vestibular evoked myogenic potentials and no response on caloric tests. The only patient with low amplitude on cervical vestibular evoked myogenic potentials had vertigo recurrence. Vertigo control was achieved in 90% of the patients. One patient developed hearing loss >30 dB. Conclusions: Cervical vestibular evoked myogenic potentials confirmed vestibular ablation in patients treated with intratympanic gentamicin. High-grade vertigo control was due to complete saccular and horizontal canal ablation (no response to iced water in electronystagmography and no response on cervical vestibular evoked myogenic potentials.

VEGF 165 Gene Therapy for Patients with Refractory Angina: Mobilization of Endothelial Progenitor Cells

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Rodrigues, Clarissa G. [Instituto de Cardiologia/Fundação Universitária de Cardiologia - Programa de Pós Graduação em Ciências da Saúde: Cardiologia, Porto Alegre, RS (Brazil); Duke University Medical Center, Durham, North Carolina (United States); Plentz, Rodrigo D.M. [Instituto de Cardiologia/Fundação Universitária de Cardiologia - Programa de Pós Graduação em Ciências da Saúde: Cardiologia, Porto Alegre, RS (Brazil); Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS (Brazil); Dipp, Thiago [Instituto de Cardiologia/Fundação Universitária de Cardiologia - Programa de Pós Graduação em Ciências da Saúde: Cardiologia, Porto Alegre, RS (Brazil); Salles, Felipe B. [Instituto de Cardiologia/Fundação Universitária de Cardiologia - Programa de Pós Graduação em Ciências da Saúde: Cardiologia, Porto Alegre, RS (Brazil); Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS (Brazil); Giusti, Imarilde I.; Sant' Anna, Roberto T.; Eibel, Bruna; Nesralla, Ivo A.; Markoski, Melissa [Instituto de Cardiologia/Fundação Universitária de Cardiologia - Programa de Pós Graduação em Ciências da Saúde: Cardiologia, Porto Alegre, RS (Brazil); Beyer, Nance N. [Instituto de Cardiologia/Fundação Universitária de Cardiologia - Programa de Pós Graduação em Ciências da Saúde: Cardiologia, Porto Alegre, RS (Brazil); Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Kalil, Renato A. K., E-mail: kalil.pesquisa@gmail.com [Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS (Brazil)

2013-08-15

Vascular endothelial growth factor (VEGF) induces mobilization of endothelial progenitor cells (EPCs) with the capacity for proliferation and differentiation into mature endothelial cells, thus contributing to the angiogenic process. We sought to assess the behavior of EPCs in patients with ischemic heart disease and refractory angina who received an intramyocardial injections of 2000 µg of VEGF 165 as the sole therapy. The study was a subanalysis of a clinical trial. Patients with advanced ischemic heart disease and refractory angina were assessed for eligibility. Inclusion criteria were as follows: signs and symptoms of angina and/or heart failure despite maximum medical treatment and a myocardial ischemic area of at least 5% as assessed by single-photon emission computed tomography (SPECT). Exclusion criteria were as follows: age > 65 years, left ventricular ejection fraction < 25%, and a diagnosis of cancer. Patients whose EPC levels were assessed were included. The intervention was 2000 µg of VEGF 165 plasmid injected into the ischemic myocardium. The frequency of CD34+/KDR+ cells was analyzed by flow cytometry before and 3, 9, and 27 days after the intervention. A total of 9 patients were included, 8 males, mean age 59.4 years, mean left ventricular ejection fraction of 59.3% and predominant class III angina. The number of EPCs on day 3 was significantly higher than that at baseline (p = 0.03); however, that on days 9{sup th} and 27{sup th} was comparable to that at baseline. We identified a transient mobilization of EPCs, which peaked on the 3th day after VEGF 165 gene therapy in patients with refractory angina and returned to near baseline levels on 9{sup th} and 27{sup th}days.

Long-term follow-up of pallidal Deep Brain Stimulation in teenagers with refractory Tourette syndrome and comorbid psychiatric disorders: About three cases.

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Hauseux, P-A; Cyprien, F; Cif, L; Gonzalez, V; Boulenger, J-P; Coubes, P; Capdevielle, D

2017-01-01

Tourette syndrome (TS) is a complex neuropsychiatric disorder associated with comorbid psychiatric disorders. Peak of tic severity typically occurs in early adolescence and impacts quality of life. Since 1999, promising therapeutic effects of Deep Brain Stimulation (DBS) have been reported in tic reduction for adults with refractory TS. The aim of the study was to assess the long-term risk-benefit ratio of pallidal DBS for young patients with refractory TS and severe comorbid psychiatric disorders. We retrospectively assessed the long-term clinical outcomes of three adolescents who underwent pallidal DBS for the treatment of refractory TS. The mean duration of follow-up was 52 months in our case series. We observed that motor tics decreased with posteroventral GPi DBS in all patients, without reaching a continuous significance over the long-term follow-up. Self-reported social inclusion was globally improved, despite lack of efficacy of DBS on comorbid conditions. These findings suggest a long-term therapeutic benefit of early DBS intervention for highly socially impaired young patients suffering from intractable TS with severe comorbid psychiatric conditions. Further studies are needed to determine the most effective targets of DBS on both tics and comorbid psychiatric profile of TS. Copyright © 2016 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

Immunomodulatory therapy in refractory/recurrent ovarian cancer.

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Chen, Chao-Yu; Lai, Chyong-Huey; Yang, Lan-Yan; Tang, Yun-Hsin; Chou, Hung-Hsueh; Chang, Chee-Jen; Lin, Cheng-Tao

2015-04-01

To investigate the efficacy and toxicity of immunomodulatory therapy (IMT) alone or as an add-on to palliative/salvage chemotherapy in patients with refractory/recurrent epithelial ovarian cancer (EOC). We retrospectively analyzed the efficacy and toxicity of IMT in 15 patients with refractory/recurrent EOC who had previously received multiple chemotherapy regimens. The median age of the patients was 56 years (range, 41-75 years). Three patients were platinum-sensitive, two were platinum-resistant, and the remaining 10 patients were refractory to platinum-based front-line chemotherapy. IMT consisted of picibanil (OK-432) on Day 1, interleukin-2 and/or interferon-α on Day 2 administered by subcutaneous injection (every week or 2-weekly). Five patients never received metronomic oral cyclophosphamide. After IMT, three patients achieved partial remission (PR, lasting for 11 months, ≥ 12 months, and 16 months), and six patients had stable disease (SD). The disease stabilizing rate (PR+SD) was 60% (3/3 in platinum-sensitive and 6/12 in platinum-resistant/refractory patients). The absolute lymphocyte count (ALC) at 1 month after IMT was significantly higher in the PR+SD group (median 1242.0/μL) than in the progression group (median 325.0/μL) (p = 0.012). No ≥ Grade 3 toxicities were observed. The median post-IMT survival time was 12 months (range, 2-39 months). IMT alone or add-on to palliative/salvage chemotherapy for refractory/recurrent EOC achieves a substantial disease stabilizing rate without severe toxicity, which might be a potential option in selected patients. The ALC 1 month after IMT could be an early indicator to disease stabilization. Copyright © 2015. Published by Elsevier B.V.

Microbe-like inclusions in tree resins and implications for the fossil record of protists in amber.

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Thiel, V; Lausmaa, J; Sjövall, P; Ragazzi, E; Seyfullah, L J; Schmidt, A R

2016-07-01

During the past two decades, a plethora of fossil micro-organisms have been described from various Triassic to Miocene ambers. However, in addition to entrapped microbes, ambers commonly contain microscopic inclusions that sometimes resemble amoebae, ciliates, microfungi, and unicellular algae in size and shape, but do not provide further diagnostic features thereof. For a better assessment of the actual fossil record of unicellular eukaryotes in amber, we studied equivalent inclusions in modern resin of the Araucariaceae; this conifer family comprises important amber-producers in Earth history. Using time-of-flight secondary ion mass spectrometry (ToF-SIMS), we investigated the chemical nature of the inclusion matter and the resin matrix. Whereas the matrix, as expected, showed a more hydrocarbon/aromatic-dominated composition, the inclusions contain abundant salt ions and polar organics. However, the absence of signals characteristic for cellular biomass, namely distinctive proteinaceous amino acids and lipid moieties, indicates that the inclusions do not contain microbial cellular matter but salts and hydrophilic organic substances that probably derived from the plant itself. Rather than representing protists or their remains, these microbe-like inclusions, for which we propose the term 'pseudoinclusions', consist of compounds that are immiscible with the terpenoid resin matrix and were probably secreted in small amounts together with the actual resin by the plant tissue. Consequently, reports of protists from amber that are only based on the similarity of the overall shape and size to extant taxa, but do not provide relevant features at light-microscopical and ultrastructural level, cannot be accepted as unambiguous fossil evidence for these particular groups. © 2016 John Wiley & Sons Ltd.

Analysis of Stress and Strain Fields in and around Inclusions of Various Shapes in a Cylindrical Specimen Loaded in Tension

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Neimitz A.

2016-06-01

Full Text Available A numerical analysis is performed of the stress field in and around inclusions of various shapes. Inclusions both stiffer and more compliant than the metal matrix are analysed. The critical stresses required for inclusion fracture are estimated after observation of cavities and inclusions by scanning electron microscopy. Real inclusions were observed after performing uniaxial loading to different amounts of overall strain. The material tested was Hardox-400 steel.

Fluid Inclusion Study of Quartz Xenocrysts in Mafic Dykes from Kawant Area, Chhota Udaipur District, Gujarat, India

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Randive Kirtikumar

2015-09-01

Full Text Available Unusual mafic dykes occur in the proximity of the Ambadongar Carbonatite Complex, Lower Narmada Valley, Gujarat, India. The dykes contain dense population of quartz xenocrysts within the basaltic matrix metasomatised by carbonate-rich fluids. Plagioclase feldspars, relict pyroxenes, chlorite, barite, rutile, magnetite, Fe-Ti oxides and glass were identified in the basaltic matrix. Quartz xenocrysts occur in various shapes and sizes and form an intricate growth pattern with carbonates. The xenocrysts are fractured and contain several types of primary and secondary, single phase and two-phase fluid inclusions. The two-phase inclusions are dominated by aqueous liquid, whereas the monophase inclusions are composed of carbonic gas and the aqueous inclusions homogenize to liquid between 226°C and 361°C. Majority of the inclusions are secondary in origin and are therefore unrelated to the crystallization of quartz. Moreover, the inclusions have mixed carbonic-aqueous compositions that inhibit their direct correlation with the crustal or mantle fluids. The composition of dilute CO2-rich fluids observed in the quartz xenocrysts appear similar to those exsolved during the final stages of evolution of the Amba Dongar carbonatites. However, the carbonates are devoid of fluid inclusions and therefore their genetic relation with the quartz xenocrysts cannot be established.

Matrix isolation as a tool for studying interstellar chemical reactions

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Ball, David W.; Ortman, Bryan J.; Hauge, Robert H.; Margrave, John L.

1989-01-01

Since the identification of the OH radical as an interstellar species, over 50 molecular species were identified as interstellar denizens. While identification of new species appears straightforward, an explanation for their mechanisms of formation is not. Most astronomers concede that large bodies like interstellar dust grains are necessary for adsorption of molecules and their energies of reactions, but many of the mechanistic steps are unknown and speculative. It is proposed that data from matrix isolation experiments involving the reactions of refractory materials (especially C, Si, and Fe atoms and clusters) with small molecules (mainly H2, H2O, CO, CO2) are particularly applicable to explaining mechanistic details of likely interstellar chemical reactions. In many cases, matrix isolation techniques are the sole method of studying such reactions; also in many cases, complexations and bond rearrangements yield molecules never before observed. The study of these reactions thus provides a logical basis for the mechanisms of interstellar reactions. A list of reactions is presented that would simulate interstellar chemical reactions. These reactions were studied using FTIR-matrix isolation techniques.

[Therapy-resistant and therapy-refractory arterial hypertension].

Science.gov (United States)

Wallbach, M; Koziolek, M J

2018-05-02

Therapy-resistant and therapy-refractory arterial hypertension differ in prevalence, pathogenesis, prognosis and therapy. In both cases, a structured approach is required, with the exclusion of pseudoresistance and, subsequently, secondary hypertension. Resistant hypertension has been reported to be more responsive to intensified diuretic therapy, whereas refractory hypertension is presumed to require sympathoinhibitory therapy. Once the general measures and the drug-based step-up therapy have been exhausted, interventional procedures are available.

Chemical vapor deposition of refractory metals and ceramics III

International Nuclear Information System (INIS)

Gallois, B.M.; Lee, W.Y.; Pickering, M.A.

1995-01-01

The papers contained in this volume were originally presented at Symposium K on Chemical Vapor Deposition of Refractory Metals and Ceramics III, held at the Fall Meeting of the Materials Research Society in Boston, Massachusetts, on November 28--30, 1994. This symposium was sponsored by Morton International Inc., Advanced Materials, and by The Department of Energy-Oak Ridge National Laboratory. The purpose of this symposium was to exchange scientific information on the chemical vapor deposition (CVD) of metallic and ceramic materials. CVD technology is receiving much interest in the scientific community, in particular, to synthesize new materials with tailored chemical composition and physical properties that offer multiple functionality. Multiphase or multilayered films, functionally graded materials (FGMs), ''smart'' material structures and nanocomposites are some examples of new classes of materials being produced via CVD. As rapid progress is being made in many interdisciplinary research areas, this symposium is intended to provide a forum for reporting new scientific results and addressing technological issues relevant to CVD materials and processes. Thirty four papers have been processed separately for inclusion on the data base

Refractory myasthenia gravis – clinical profile, comorbidities and response to rituximab

Science.gov (United States)

Sudulagunta, Sreenivasa Rao; Sepehrar, Mona; Sodalagunta, Mahesh Babu; Settikere Nataraju, Aravinda; Bangalore Raja, Shiva Kumar; Sathyanarayana, Deepak; Gummadi, Siddharth; Burra, Hemanth Kumar

2016-01-01

Introduction: Myasthenia gravis (MG) is an antibody mediated autoimmune neuromuscular disorder characterized by fatigable muscle weakness. A proportion of myasthenia gravis patients are classified as refractory due to non responsiveness to conventional treatment. This retrospective study was done to evaluate clinical profile, epidemiological, laboratory, and features of patients with MG and mode of management using rituximab and complications. Methods: Data of myasthenia gravis patients admitted or presented to outpatient department (previous medical records) with MG between January 2008 and January 2016 were included. A total of 512 patients fulfilled the clinical and diagnostic criteria of myasthenia gravis of which 76 patients met the diagnostic certainty for refractory myasthenia gravis and were evaluated. Results: Out of 76 refractory MG patients, 53 (69.73%) patients fulfilled all the three defined criteria. The median age of onset of the refractory MG group was 36 years with a range of 27–53 years. In our study 25 patients (32.89%) belonged to the age group of 21–30 years. Anti-MuSK antibodies were positive in 8 non-refractory MG patients (2.06%) and 36 refractory MG patients (47.36%). Mean HbA1C was found to be 8.6±2.33. The dose of administered prednisone decreased by a mean of 59.7% (p=3.3x10–8) to 94.6% (p=2.2x10–14) after the third cycle of rituximab treatment. Conclusion: The refractory MG patients are most commonly female with an early age of onset, anti-MuSK antibodies, and thymomas. Refractory MG patients have higher prevalence and poor control (HbA1C >8%) of diabetes mellitus and dyslipidemia probably due to increased steroid usage. Rituximab is very efficient in treatment of refractory MG with adverse effects being low. PMID:27790079

IMPROVED CORROSION RESISTANCE OF ALUMINA REFRACTORIES

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John P. Hurley; Patty L. Kleven

2001-09-30

The initial objective of this project was to do a literature search to define the problems of refractory selection in the metals and glass industries. The problems fall into three categories: Economic--What do the major problems cost the industries financially? Operational--How do the major problems affect production efficiency and impact the environment? and Scientific--What are the chemical and physical mechanisms that cause the problems to occur? This report presents a summary of these problems. It was used to determine the areas in which the EERC can provide the most assistance through bench-scale and laboratory testing. The final objective of this project was to design and build a bench-scale high-temperature controlled atmosphere dynamic corrosion application furnace (CADCAF). The furnace will be used to evaluate refractory test samples in the presence of flowing corrodents for extended periods, to temperatures of 1600 C under controlled atmospheres. Corrodents will include molten slag, steel, and glass. This test should prove useful for the glass and steel industries when faced with the decision of choosing the best refractory for flowing corrodent conditions.

Clinical and microbiological features of refractory periodontitis subjects.

Science.gov (United States)

Colombo, A P; Haffajee, A D; Dewhirst, F E; Paster, B J; Smith, C M; Cugini, M A; Socransky, S S

1998-02-01

The purpose of this investigation was to compare the clinical parameters and the site prevalence and levels of 40 subgingival species in successfully treated and refractory periodontitis subjects. 94 subjects received scaling and root planing and if needed, periodontal surgery and systemically administered tetracycline. 28 refractory subjects showed mean full mouth attachment loss and/or > 3 sites showing attachment loss > 2.5 mm within 1 year post-therapy. 66 successfully treated subjects showed mean attachment level gain and no sites with attachment loss > 2.5 mm. Baseline subgingival plaque samples were taken from the mesial aspect of each tooth and the presence and levels of 40 subgingival taxa were determined using whole genomic DNA probes and checkerboard DNA-DNA hybridization. The mean levels and % of sites colonized by each species (prevalence) was computed for each subject and differences between groups sought using the Mann-Whitney test. Most of the 40 species tested, including Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola and Bacteroides forsythus, were equally or less prevalent in the refractory group. Prevotella nigrescens was significantly more prevalent in successfully treated subjects, while refractory subjects harbored a larger proportion of Streptococcus species, particularly Streptococcus constellatus. The odds of a subject being refractory was 8.6 (p or = 3.5% of the total DNA probe count. Since few microbiological differences existed between treatment outcome groups using DNA probes to known species, the predominant cultivable microbiota of 33 subgingival samples from 14 refractory subjects was examined. 85% of the 1649 isolates were identified using probes to 69 recognized subgingival species. The remaining unidentified strains were classified by analyzing 16S rRNA gene sequences. Many sequenced isolates were of taxa not considered a common part of the oral microbiota such as Acinetobacter baumanni

Inclusion Detection in Aluminum Alloys Via Laser-Induced Breakdown Spectroscopy

Science.gov (United States)

Hudson, Shaymus W.; Craparo, Joseph; De Saro, Robert; Apelian, Diran

2018-04-01

Laser-induced breakdown spectroscopy (LIBS) has shown promise as a technique to quickly determine molten metal chemistry in real time. Because of its characteristics, LIBS could also be used as a technique to sense for unwanted inclusions and impurities. Simulated Al2O3 inclusions were added to molten aluminum via a metal-matrix composite. LIBS was performed in situ to determine whether particles could be detected. Outlier analysis on oxygen signal was performed on LIBS data and compared to oxide volume fraction measured through metallography. It was determined that LIBS could differentiate between melts with different amounts of inclusions by monitoring the fluctuations in signal for elements of interest. LIBS shows promise as an enabling tool for monitoring metal cleanliness.

Superplastic flow of two-phase ceramics containing rigid inclusions-zirconia/mullite composites

International Nuclear Information System (INIS)

Yoon, C.K.; Chen, I.W.

1990-01-01

A continuum theory for non-newtonian flow of a two-phase composite containing rigid inclusions is presented. It predicts flow suppression by a factor of (1 - V) q , where V is the volume fraction of the rigid inclusion and q depends on the stress exponent and the inclusion shape. Stress concentrations in the rigid inclusion have also been evaluated. As the stress exponent increases, flow suppression is more pronounced even though stress concentration is less severe. To test this theory, superplastic flow of zirconia/mullite composites, in which zirconia is a soft, non-Newtonian super-plastic matrix and mullite is a rigid phase of various size, shape, and amount, is studied. The continuum theory is found to describe the two-phase superplastic flow reasonably well

Effects of shape and size of inclusions on the sintering of ZnO-ZrO2 composites

International Nuclear Information System (INIS)

Nakada, Yohsuke; Kimura, Toshio

1997-01-01

The densification behavior and microstructure development of ZnO matrices containing rigid ZrO 2 inclusions were studied, with special emphasis on the effect of inclusion shape and size. The inclusions retarded the densification of the matrix, regardless of the inclusion shape and size. For large inclusions with diameter of > 10 microm, dense regions developed between inclusion particles. The inclusion particles and dense regions formed a continuous network, which constrained the densification of the composites. The inclusion shape had a small effect on the development of dense regions. Severe retardation in densification was observed for compacts containing inclusions with diameters of < 10 microm. In these cases, dense regions between inclusion particles did not develop. The formation of the continuous network cannot be applicable to small inclusions as an origin of retardation of densification

Boron-bearing species in ceramic matrix composites for long-term aerospace applications

International Nuclear Information System (INIS)

Naslain, R.; Guette, A.; Rebillat, F.; Pailler, R.; Langlais, F.; Bourrat, X.

2004-01-01

Boron-bearing refractory species are introduced in non-oxide ceramic matrix fibrous composites (such as SiC/SiC composites) to improve their oxidation resistance under load at high temperatures with a view to applications in the aerospace field. B-doped pyrocarbon and hex-BN have been successfully used as interphase (instead of pure pyrocarbon) either as homogeneous or multilayered fiber coatings, to arrest and deflect matrix cracks formed under load (mechanical fuse function) and to give toughness to the materials. A self-healing multilayered matrix is designed and used in a model composite, which combines B-doped pyrocarbon mechanical fuse layers and B- and Si-bearing compound (namely B 4 C and SiC) layers forming B 2 O 3 -based fluid healing phases when exposed to an oxidizing atmosphere. All the materials are deposited by chemical vapor infiltration. Lifetimes under tensile loading of several hundreds hours at high temperatures are reported

The evolution of complex type B Allende inclusion - An ion microprobe trace element study

Science.gov (United States)

Macpherson, Glenn J.; Crozaz, Ghislaine; Lundberg, Laura L.

1989-01-01

Results are presented of a detailed trace-element and isotopic analyses of the constituent phases in each of the major textural parts (mantle, core, and islands) of a Type B refractory inclusion, the USNM 5241 inclusion from Allende, first described by El Goresy et al. (1985). The REE data on 5241 were found to be largely consistent with a model in which the mantle and the core of 5241 formed sequentially out of a single melt by fractional crystallization. The numerical models of REE evolution in the 5241 melt, especially that of Eu, require that a significant mass of spinel-free island material was assimilated into the evolving melt during the last half of the solidification history of 5241. The trace element results pbtained thus strongly support the interpretation of El Goresy et al. (1985) that the spinel-free islands in the 5241 are trapped xenoliths.

Defining refractory migraine: results of the RHSIS Survey of American Headache Society members.

Science.gov (United States)

Schulman, Elliott A; Peterlin, B Lee; Lake, Alvin E; Lipton, Richard B; Hanlon, Alexandra; Siegel, Sherry; Levin, Morris; Goadsby, Peter J; Markley, Herbert G

2009-04-01

To gauge consensus regarding a proposed definition for refractory migraine proposed by Refractory Headache Special Interest Section, and where its use would be most appropriate. Headache experts have long recognized that a subgroup of headache sufferers remains refractory to treatment. Although different groups have proposed criteria to define refractory migraine, the definition remains controversial. The Refractory Headache Special Interest Section of the American Headache Society developed a definition through a consensus process, assisted by a literature review and initial membership survey. A 12-item questionnaire was distributed at the American Headache Society meeting in 2007 during a platform session and at the Refractory Headache Special Interest Section symposium. The same questionnaire was subsequently sent to all American Headache Society members via e-mail. A total of 151 responses from AHS members form the basis of this report. The survey instrument was designed using Survey Monkey. Frequencies and percentages of the survey were used to describe survey responses. American Headache Society members agreed that a definition for refractory migraine is needed (91%) that it should be added to the International Classification of Headache Disorders-2 (86%), and that refractory forms of non-migraine headache disorders should be defined (87%). Responders believed a refractory migraine definition would be of greatest value in selecting patients for clinical drug trials. The current refractory migraine definition requires a diagnosis of migraine, interference with function or quality of life despite modification of lifestyle factors, and adequate trials of acute and preventive medicines with established efficacy. The proposed criteria for the refractory migraine definition require failing 2 preventive medications to meet the threshold for failure. Although 42% of respondents agreed with the working definition of refractory migraine, 43% favored increasing the

The Role of Refractory Dissolved Organic Matter in Ocean Carbon Sequestration

DEFF Research Database (Denmark)

Jørgensen, Linda

The ocean assimilates a large amount of atmospheric CO2 and is potentially a buffer for climate change. A fraction of the assimilated CO2 is incorporated into algal biomass and further converted into refractory dissolved organic matter (DOM). Carbon bound in refractory DOM has the potential...... studies the prokaryotic production and degradation of oceanic refractory DOM and discusses the reasons for the persistent nature of this large DOM fraction. The first two papers investigate the microbial carbon pump, i.e. prokaryotic transfor-mation of organic carbon into refractory DOM. The results show...... DOM compounds in the ocean are rare—possibly too rare to sustain viable uptake and assimilation. Hence, the dilute concentration of individual compounds is a possible explanation for the apparent refractory nature of most DOM in the ocean. Understanding the mechanisms that control the quality...

Intraepithelial lymphocytes in refractory celiac disease : lost in transition

NARCIS (Netherlands)

Schmitz, Frederike

2014-01-01

Refractory coeliac disease type II (RCDII) is a severe complication of coeliac disease. Whereas celiac disease can successfully be treated by the strict avoidance of gluten, refractory celiac patients show no remission despite a gluten-free diet. The pathology of RCDII is only partially understood,

Clinical Features of Refractory Ascites in Outpatients

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Wanda Regina Caly

Full Text Available OBJECTIVES: To present the clinical features and outcomes of outpatients who suffer from refractory ascites. METHODS: This prospective observational study consecutively enrolled patients with cirrhotic ascites who submitted to a clinical evaluation, a sodium restriction diet, biochemical blood tests, 24 hour urine tests and an ascitic fluid analysis. All patients received a multidisciplinary evaluation and diuretic treatment. Patients who did not respond to the diuretic treatment were controlled by therapeutic serial paracentesis, and a transjugular intrahepatic portosystemic shunt was indicated for patients who required therapeutic serial paracentesis up to twice a month. RESULTS: The most common etiology of cirrhosis in both groups was alcoholism [49 refractory (R and 11 non-refractory ascites (NR]. The majority of patients in the refractory group had Child-Pugh class B cirrhosis (p=0.034. The nutritional assessment showed protein-energy malnutrition in 81.6% of the patients in the R group and 35.5% of the patients in the NR group, while hepatic encephalopathy, hernia, spontaneous bacterial peritonitis, upper digestive hemorrhage and type 2 hepatorenal syndrome were present in 51%, 44.9%, 38.8%, 38.8% and 26.5% of the patients in the R group and 9.1%, 18.2%, 0%, 0% and 0% of the patients in the NR group, respectively (p=0.016, p=0.173, p=0.012, p=0.012, and p=0.100, respectively. Mortality occurred in 28.6% of the patients in the R group and in 9.1% of the patients in the NR group (p=0.262. CONCLUSION: Patients with refractory ascites were malnourished, suffered from hernias, had a high prevalence of complications and had a high postoperative death frequency, which was mostly due to infectious processes.

A petrologic and ion microprobe study of a Vigarano Type B refractory inclusion - Evolution by multiple stages of alteration and melting

Science.gov (United States)

Macpherson, Glenn J.; Davis, Andrew M.

1993-01-01

A Type B Ca-, Al-rich 6-m-diam inclusion (CAI) found in the Vigarano C3V chondrite was inspected using optical and scanning electron microscopies and ion microprobe analyses. It was found that the primary constituents of the CAI inclusion are (in percent), melilite (52), fassaite, (20), anorthite (18), spinel (10), and trace Fe-Ni metal. It is noted that, while many of the properties of the inclusion indicate solidification from a melt droplet, the Al-26/Mg-26 isotopic systematics and some textural relationships are incompatible with single-stage closed system crystallization of a homogeneous molten droplet, indicating that the history of this inclusion must have been more complex than melt solidification alone. Moreover, there was unusually high content of Na in melilite, suggesting that the droplet did not form by melting of pristine high-temperature nebular condensates.

Modification of Alumina and Spinel Inclusions by Calcium in Liquid Steel

Science.gov (United States)

Verma, Neerav

2011-12-01

samples were characterized for inclusion shape, size and chemistry through scanning electron microscopy (SEM). Automated inclusion analysis tools (like ASCAT [59, 91, 92], INCA-GSR [126]; Please refer section 6.4., page number 68) were employed to generate statistical information of the inclusions. Thermodynamic database software FACTSAGE [62] was used to determine thermochemistry of reactions, ternary phase diagrams (Ca-Al-S and Ca-Al-Mg systems). The compositions of the inclusions were tracked before and after calcium treatment to determine the effectiveness of calcium treatment. Extraction of inclusions through dissolution of iron in bromine-methanol solution was employed to reveal 3-D geometry of inclusions and analyze inclusions through EDS (Energy-dispersive X-ray spectroscopy) without any matrix effects. Various industrial samples were also analyzed to confirm the feasibility of various reaction mechanisms deduced through experiments. Successful modification of alumina and spinel inclusions by calcium was demonstrated [85, 86]. It was observed that these modification mechanisms proceed through transient phase (CaO, CaS) formation. In the case of spinels, preferential reduction of MgO part was also observed during calcium modification of spinels. The magnesium after MgO reduction by calcium can enter back into the melt or leave the melt in vapor form. The inclusion area fraction decreased after calcium treatment, but the inclusion concentration (number of inclusions per cm2) increased because inclusions shifted to a smaller size distribution after calcium treatment. Severe matrix effects during EDS analysis of inclusions were observed, due to which inclusion composition analyses can be significantly affected. *Please refer to dissertation for footnotes.

Resistant and Refractory Hypertension: Antihypertensive Treatment Resistance vs Treatment Failure

Science.gov (United States)

Siddiqui, Mohammed; Dudenbostel, Tanja; Calhoun, David A.

2017-01-01

Resistant or difficult to treat hypertension is defined as high blood pressure that remains uncontrolled with 3 or more different antihypertensive medications, including a diuretic. Recent definitions also include controlled blood pressure with use of 4 or more medications as also being resistant to treatment. Recently, refractory hypertension, an extreme phenotype of antihypertensive treatment failure has been defined as hypertension uncontrolled with use of 5 or more antihypertensive agents, including a long-acting thiazide diuretic and a mineralocorticoid receptor antagonist. Patients with resistant vs refractory hypertension share similar characteristics and comorbidities, including obesity, African American race, female sex, diabetes, coronary heart disease, chronic kidney disease, and obstructive sleep apnea. Patients with refractory vs resistant hypertension tend to be younger and are more likely to have been diagnosed with congestive heart failure. Refractory hypertension might also differ from resistant hypertension in terms of underlying cause. Preliminary evidence suggests that refractory hypertension is more likely to be neurogenic in etiology (ie, heightened sympathetic tone), vs a volume-dependent hypertension that is more characteristic of resistant hypertension in general. PMID:26514749

Performance assessment of refractory samples in the Los Alamos Controlled Air Incinerator

International Nuclear Information System (INIS)

Hutchins, D.A.; Borduin, L.C.; Koenig, R.A.; Vavruska, J.S.; Warner, C.L.

1986-01-01

A refractory evaluation project was initiated in 1979 to study the performance of six selected refractory materials within the Los Alamos Controlled Air Incinerator (CAI). Determining refractory resistance to thermal shock, chemical attack, and plutonium uptake was of particular interest. The experimental refractories were subjected to a variety of waste materials, including transuranic (TRU) contaminated wastes, highly chlorinated compounds and alkaline metal salts of perchlorate, chlorate, nitrate and oxylate, over the six year period of this study. Results of this study to date indicate that the use of high alumina, and possibly specialty plastic refractories, is advisable for the lining of incinerators used for the thermal destruction of diverse chemical compounds. 12 refs., 4 tabs

Sub-surface Fatigue Crack Growth at Alumina Inclusions in AISI 52100 Roller Bearings

DEFF Research Database (Denmark)

Cerullo, Michele

2014-01-01

Sub-surface fatigue crack growth at non metallic inclusions is studied in AISI 52100 bearing steel under typical rolling contact loads. A first 2D plane strain finite element analysis is carried out to compute the stress history in the innner race at a characteristic depth, where the Dang Van...... damage factor is highest. Subsequently the stress history is imposed as boundary conditions in a periodic unit cell model, where an alumina inclusion is embedded in a AISI 52100 matrix. Cracks are assumed to grow radially from the inclusion under cyclic loading. The growth is predicted by means...

White-Coat Effect Is Uncommon in Patients With Refractory Hypertension.

Science.gov (United States)

Siddiqui, Mohammed; Judd, Eric K; Oparil, Suzanne; Calhoun, David A

2017-09-01

Refractory hypertension is a recently described phenotype of antihypertensive treatment failure defined as uncontrolled blood pressure (BP) despite the use of ≥5 different antihypertensive agents, including chlorthalidone and spironolactone. Recent studies indicate that refractory hypertension is uncommon, with a prevalence of ≈5% to 10% of patients referred to a hypertension specialty clinic for uncontrolled hypertension. The prevalence of white-coat effect, that is, uncontrolled automated office BP ≥135/85 mm Hg and controlled out-of-office BP hypertensive patients overall is ≈30% to 40%. The prevalence of white-coat effect among patients with refractory hypertension has not been previously reported. In this prospective evaluation, consecutive patients referred to the University of Alabama at Birmingham Hypertension Clinic for uncontrolled hypertension were enrolled. Refractory hypertension was defined as uncontrolled automated office BP ≥135/85 mm Hg with the use of ≥5 antihypertensive agents, including chlorthalidone and spironolactone. Automated office BP measurements were based on 6 serial readings, done automatically with the use of a BpTRU device unobserved in the clinic. Out-of-office BP measurements were done by 24-hour ambulatory BP monitor. Thirty-four patients were diagnosed with refractory hypertension, of whom 31 had adequate ambulatory BP monitor readings. White-coat effect was present in only 2 patients, or 6.5% of the 31 patients with refractory hypertension, suggesting that white-coat effect is largely absent in patients with refractory hypertension. These findings suggest that white-coat effect is not a common cause of apparent lack of BP control in patients failing maximal antihypertensive treatment. © 2017 American Heart Association, Inc.

Friction measurements of steel on refractory bricks

International Nuclear Information System (INIS)

Eiselstein, L.E.

1981-08-01

During startup or shutdown of a pool-type LMFBR, substantial shear stresses may arise between the base of the steel reactor vessel and the refractory brick support base. The magnitude of these stresses, which result from differences in thermal expansion, can be estimated if the friction coefficient is known. This report describes experiments to determine friction coefficients between 2 1/4 Cr-1Mo steel and several refractory materials and to examine effects to contact pressure, temperature, sliding velocity, lubricants, and surface condition

Characterization of refractory brick based on local raw material from Lampung Province - Indonesia

Science.gov (United States)

Amin, Muhammad; Suryana, Yayat I.; Isnugroho, Kusno; Aji, Bramantyo B.; Birawidha, David C.; Hendronursito, Yusup

2018-04-01

Refractories are non-metallic inorganic materials that are difficult to melt at high temperatures and used in high-temperature casting industries. Refractories are classified into their constituent mineral feed stocks, refractories having typical plot properties commonly called fire bricks. In the manufacture of refractory bricks that exist in the market during the use of mangrove materials derived from abroad that is from China. In this research the refractory brick materials used are quartz sand, feldspart, kaolin, bentonite, and ball clay. All materials come from local Lampung Province - Indonesia. The experiment, there are 7 kinds of experimental composition, made of plot shape with size 230 mm, 65 mm in thickness, 114 mm height mould using manual press machine with 10 tons power and burning at 1400°C for 5 hours. Refractory brick product is done by physical test in the form of porosity, specific gravity, compressive strength and XRF and SEM characteristics. The result of XRF characteristic of refractory brick composition of 1 to 5 compared to the refractory brick type SK 34 in the market and the result of composition 1 is a composition close to refractory brick composition type SK 34 namely SiO2 is 54.21 %, Al2O3 is 25.38 % and test Physical of Bulk density is 2.25 g/cm3, porosity is 18.98 % and compressive strength is 325 kg/cm2.

Annealing studies of Bi and Kr inclusions in Al

Energy Technology Data Exchange (ETDEWEB)

Bjoern Thoft, N

1995-04-01

This report contains the results of experimental investigations of melting, solidification and growth of Bi and Kr inclusions made by ion implantation into aluminium. The experimental techniques used of for this study were x-ray diffraction, transmission electron microscopy, Rutherford backscattering, ion channeling, and grazing-incidence small-angle x-ray scattering. The x-ray diffraction signal from crystalline Bi inclusions in Al has been recorded as a function of temperature during heating to temperatures above the bulk melting point and cooling to room temperature. Data from these measurements have been fitted using models (developed by Pawlow and Wronski) for the size-dependent melting temperature of small particles, and size distributions for the inclusions have been determined in this way. Transmission electron microscopy has confirmed the melting and solidification of the Bi inclusions in the temperature ranges, in which these processes were observed by x-ray diffraction, establishing the facts that the inclusions melt below the bulk melting point and that a large supercooling is seen. Information about the amount and depth distribution of the Bi confined in the Al matrix has been derived from Rutherford backscattering measurements. Melting and solidification of Bi inclusions have been observed by means of ion channeling. The results of the investigations of bismuth inclusions in aluminium are compared to previous, similar results for lead inclusions in aluminium. Finally, preliminary experiments have confirmed that growth of Kr inclusions in Al can be observed using grazing-incidence small-angle scattering. (au) (13 tabs., 46 ills., 77 refs.).

Annealing studies of Bi and Kr inclusions in Al

International Nuclear Information System (INIS)

Bjoern Thoft, N.

1995-04-01

This report contains the results of experimental investigations of melting, solidification and growth of Bi and Kr inclusions made by ion implantation into aluminium. The experimental techniques used of for this study were x-ray diffraction, transmission electron microscopy, Rutherford backscattering, ion channeling, and grazing-incidence small-angle x-ray scattering. The x-ray diffraction signal from crystalline Bi inclusions in Al has been recorded as a function of temperature during heating to temperatures above the bulk melting point and cooling to room temperature. Data from these measurements have been fitted using models (developed by Pawlow and Wronski) for the size-dependent melting temperature of small particles, and size distributions for the inclusions have been determined in this way. Transmission electron microscopy has confirmed the melting and solidification of the Bi inclusions in the temperature ranges, in which these processes were observed by x-ray diffraction, establishing the facts that the inclusions melt below the bulk melting point and that a large supercooling is seen. Information about the amount and depth distribution of the Bi confined in the Al matrix has been derived from Rutherford backscattering measurements. Melting and solidification of Bi inclusions have been observed by means of ion channeling. The results of the investigations of bismuth inclusions in aluminium are compared to previous, similar results for lead inclusions in aluminium. Finally, preliminary experiments have confirmed that growth of Kr inclusions in Al can be observed using grazing-incidence small-angle scattering. (au) (13 tabs., 46 ills., 77 refs.)

Refractory benign esophageal strictures

Directory of Open Access Journals (Sweden)

Gopal Goyal

2016-01-01

Full Text Available Refractory benign esophageal stricture (RBES is a frequently encountered problem worldwide. These strictures arise from various causes such as corrosive injury, radiation therapy, peptic origin, ablative therapy, and after surgery. Most strictures can be treated successfully with endoscopic dilatation using bougies or balloons, with only a few complications. Those patients who fail after serial dilatation with bougies or balloons will come to the category of refractory strictures. Dilatation combined with intralesional steroid injections can be considered for peptic strictures, whereas incisional therapy has been demonstrated to be effective for short anastomotic strictures. When these therapeutic options do not resolve the stenosis, stent placement should be considered. Self-bougienage can be proposed to a selected group of patients with a proximal stenosis. Most of the patients of RBES respond to above-mentioned treatment and occasional patient may require surgery as the final treatment option. This review aims to provide a comprehensive approach toward endoscopic management of RBESs based on current literature and personal experience.

Illness identity in young adults with refractory epilepsy.

Science.gov (United States)

Luyckx, Koen; Oris, Leen; Raymaekers, Koen; Rassart, Jessica; Moons, Philip; Verdyck, Ludo; Mijnster, Teus; Mark, Ruth E

2018-03-01

Refractory epilepsy is an intrusive condition with important implications for daily functioning in emerging and young adulthood. The present study examined the degree to which refractory epilepsy is integrated in one's identity, and examined how such a sense of illness identity was related to health-related quality of life (HRQOL). A total of 121 18- to 40-year-old patients with refractory epilepsy (56.2% women) completed self-report questionnaires assessing the four illness identity states of acceptance, enrichment, engulfment, and rejection (Illness Identity Questionnaire (IIQ)); HRQOL (Quality of Life in Epilepsy Inventory - 31); and seizure frequency and severity (Liverpool Seizure Severity Scale (LSSS)). Illness identity scores were compared with a sample of 191 patients with a nonneurological chronic disease (congenital heart disease). Hierarchical regression analyses were conducted to assess the predictive value of illness identity for HRQOL when simultaneously controlling for demographic and clinical features. Patients with refractory epilepsy scored higher on rejection and engulfment and lower on acceptance when compared with patients with congenital heart disease. Further, seizure severity and number of medication side-effects were positively related to engulfment and negatively to acceptance. Finally, when simultaneously controlling for various demographic and clinical variables, illness identity significantly predicted HRQOL (with engulfment being the strongest and most consistent predictor). The extent to which patients with refractory epilepsy succeed in integrating their illness into their identity may have important implications for HRQOL. Clinicians should be especially attentive for signs that patients feel engulfed by their epilepsy. Copyright © 2018 Elsevier Inc. All rights reserved.

Ketogenic diet treatment for pediatric super-refractory status epilepticus.

Science.gov (United States)

Appavu, Brian; Vanatta, Lisa; Condie, John; Kerrigan, John F; Jarrar, Randa

2016-10-01

We aimed to study whether ketogenic diet (KD) therapy leads to resolution of super-refractory status epilepticus in pediatric patients without significant harm. A retrospective review was performed at Phoenix Children's Hospital on patients with super-refractory status epilepticus undergoing ketogenic diet therapy from 2011 to 2015. Ten children with super-refractory status epilepticus, ages 2-16 years, were identified. 4/10 patients had immune mediated encephalitis, including Rasmussen encephalitis, anti-N-methyl-d-aspartate receptor encephalitis, and post-infectious mycoplasma encephalitis. Other etiologies included Lennox Gastaut Syndrome, non-ketotic hyperglycinemia, PCDH19 and GABRG2 genetic epilepsy, New Onset Refractory Status Epilepticus, and Febrile Infection-Related Epilepsy Syndrome. 4/10 patients' EEG features suggested focal with status epilepticus, and 6/10 suggested generalized with status epilepticus. Median hospital length was 61days and median ICU length was 27days. The median number of antiepileptic medications prior to diet initiation was 3.0 drugs, and the median after ketogenic diet treatment was 3.5 drugs. Median duration of status epilepticus prior to KD was 18days. 9/10 patients had resolution of super-refractory status epilepticus in a median of 7days after diet initiation. 8/9 patients were weaned off anesthesia within 15days of diet initiation, and within 1day of achieving ketonuria. 1/10 patients experienced side effects on the diet requiring supplementation. Most patients achieved resolution of status epilepticus on KD therapy, suggesting it could be an effective therapy that can be utilized early in the treatment of children with super refractory status epilepticus. Copyright © 2016. Published by Elsevier Ltd.

Exponential formula for the reachable sets of quantum stochastic differential inclusions

International Nuclear Information System (INIS)

Ayoola, E.O.

2001-07-01

We establish an exponential formula for the reachable sets of quantum stochastic differential inclusions (QSDI) which are locally Lipschitzian with convex values. Our main results partially rely on an auxiliary result concerning the density, in the topology of the locally convex space of solutions, of the set of trajectories whose matrix elements are continuously differentiable By applying the exponential formula, we obtain results concerning convergence of the discrete approximations of the reachable set of the QSDI. This extends similar results of Wolenski for classical differential inclusions to the present noncommutative quantum setting. (author)

Multi-length-scale Material Model for SiC/SiC Ceramic-Matrix Composites (CMCs): Inclusion of In-Service Environmental Effects

Science.gov (United States)

Grujicic, M.; Galgalikar, R.; Snipes, J. S.; Ramaswami, S.

2016-01-01

In our recent work, a multi-length-scale room-temperature material model for SiC/SiC ceramic-matrix composites (CMCs) was derived and parameterized. The model was subsequently linked with a finite-element solver so that it could be used in a general room-temperature, structural/damage analysis of gas-turbine engine CMC components. Due to its multi-length-scale character, the material model enabled inclusion of the effects of fiber/tow (e.g., the volume fraction, size, and properties of the fibers; fiber-coating material/thickness; decohesion properties of the coating/matrix interfaces; etc.) and ply/lamina (e.g., the 0°/90° cross-ply versus plain-weave architectures, the extent of tow crimping in the case of the plain-weave plies, cohesive properties of the inter-ply boundaries, etc.) length-scale microstructural/architectural parameters on the mechanical response of the CMCs. One of the major limitations of the model is that it applies to the CMCs in their as-fabricated conditions (i.e., the effect of prolonged in-service environmental exposure and the associated material aging-degradation is not accounted for). In the present work, the model is upgraded to include such in-service environmental-exposure effects. To demonstrate the utility of the upgraded material model, it is used within a finite-element structural/failure analysis involving impact of a toboggan-shaped turbine shroud segment by a foreign object. The results obtained clearly revealed the effects that different aspects of the in-service environmental exposure have on the material degradation and the extent of damage suffered by the impacted CMC toboggan-shaped shroud segment.

Refractory episodic vertigo: role of intratympanic gentamicin and vestibular evoked myogenic potentials.

Science.gov (United States)

Celis-Aguilar, Erika; Hinojosa-González, Ramon; Vales-Hidalgo, Olivia; Coutinho-Toledo, Heloisa

Even today, the treatment of intractable vertigo remains a challenge. Vestibular ablation with intratympanic gentamicin stands as a good alternative in the management of refractory vertigo patients. To control intractable vertigo through complete saccular and horizontal canal vestibular ablation with intratympanic gentamicin treatment. Patients with refractory episodic vertigo were included. The inclusion criteria were: unilateral ear disease, moderate to profound sensorineural hearing loss, and failure to other treatments. Included patients underwent 0.5-0.8mL of gentamicin intratympanic application at a 30mg/mL concentration. Vestibular ablation was confirmed by the absence of response on cervical vestibular evoked myogenic potentials and no response on caloric tests. Audiometry, electronystagmography with iced water, and vestibular evoked myogenic potentials were performed in all patients. Ten patients were included; nine patients with Meniere's disease and one patient with (late onset) delayed hydrops. Nine patients showed an absent response on vestibular evoked myogenic potentials and no response on caloric tests. The only patient with low amplitude on cervical vestibular evoked myogenic potentials had vertigo recurrence. Vertigo control was achieved in 90% of the patients. One patient developed hearing loss >30dB. Cervical vestibular evoked myogenic potentials confirmed vestibular ablation in patients treated with intratympanic gentamicin. High-grade vertigo control was due to complete saccular and horizontal canal ablation (no response to iced water in electronystagmography and no response on cervical vestibular evoked myogenic potentials). Copyright © 2016 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Central Diabetes Insipidus in Refractory Antineutrophil Cytoplasmic Antibody-associated Vasculitis.

Science.gov (United States)

Ohashi, Keiji; Morishita, Michiko; Watanabe, Haruki; Sada, Ken-Ei; Katsuyama, Takayuki; Miyawaki, Yoshia; Katsuyama, Eri; Narazaki, Mariko; Tatebe, Noriko; Watanabe, Katsue; Kawabata, Tomoko; Wada, Jun

2017-11-01

We herein describe two cases of refractory antineutrophil cytoplasmic antibody-associated vasculitis (AAV) complicated with diabetes insipidus (DI) possibly related to hypertrophic pachymeningitis (HP). One patient had microscopic polyangiitis and HP, which were refractory to cyclophosphamide, azathioprine, rituximab, mycophenolate mofetil (MMF), and mizoribine. Remission was finally achieved with the use of etanercept, but DI occurred 5 years later. The other patient had granulomatosis with polyangiitis, which that was refractory to cyclophosphamide, methotrexate, MMF, and rituximab. DI subsequently developed, but was successfully treated with etanercept. Dura mater hypertrophy was macroscopically observed in the latter case.

The method of quantitative X-ray microanalysis of fine inclusions in copper

International Nuclear Information System (INIS)

Morawiec, H.; Kubica, L.; Piszczek, J.

1978-01-01

The method of correction for the matrix effect in quantitative x-ray microanalysis was presented. The application of the method was discussed on the example of quantitative analysis of fine inclusions of Cu 2 S and Cu 2 O in copper. (author)

Lack of effect of methotrexate in budesonide-refractory collagenous colitis

Directory of Open Access Journals (Sweden)

Münch A

2013-08-01

Full Text Available Andreas Münch,1,* Johan Bohr,2,3,* Lina Vigren,4 Curt Tysk,2,3,* Magnus Ström1,* 1Division of Gastroenterology and Hepatology, Department of Clinical and Experimental Medicine, Faculty of Health Science, Linköping University, Linköping, 2Division of Gastroenterology, Department of Medicine, Örebro University Hospital, Örebro University, Örebro, 3School of Health and Medical Science, Örebro University, Örebro, 4Division of Gastroenterology, Department of Clinical Science, Lund University, Malmö, Sweden *These authors are members of the Swedish Organization for the study of Inflammatory Bowel Disease (SOIBD, a national organization for gastroenterologists, colorectal surgeons, and basic scientists Background: In most cases, collagenous colitis can be treated effectively with budesonide. However, some patients develop side effects or have chronic symptoms refractory to budesonide. This paper reports an open case series of patients intolerant or refractory to budesonide who were treated with methotrexate (MTX. Methods and patients: Nine patients (seven women with a median (range age of 62 (44–77 years were studied. Bowel movements were registered during 1 week prior to baseline and after 6 and 12 weeks’ treatment, enabling calculation of the mean bowel movements/day. All patients underwent colonoscopy with biopsies before inclusion to confirm diagnosis. Open treatment with MTX was given 15 mg subcutaneously weekly for 6 weeks and was increased to 25 mg for a further 6 weeks if symptoms were unresponsive to the first 6 weeks’ treatment. The endpoint was clinical remission, which was defined as a mean <3 stools/day and mean <1 watery stool/day/week at Week 12. The Short Health Scale was used at baseline and Week 12 to assess health-related quality of life. Results: Five patients fulfilled the treatment according to the protocol and four patients discontinued the study after 3–6 weeks because of adverse events. No patient achieved

On the nature and origin of garnet in highly-refractory Archean lithosphere: implications for continent stabilisation

Science.gov (United States)

Gibson, Sally

2014-05-01

The nature and timescales of garnet formation in the Earth's subcontinental lithospheric mantle (SCLM) are important to our understanding of how this rigid outer shell has evolved and stabilised since the Archean. Nevertheless, the widespread occurrence of pyrope garnet in the sub-cratonic mantle remains one of the 'holy grails' of mantle petrology. The paradox is that garnet often occurs in mantle lithologies (dunites and harzburgites) which represent residues of major melting events (up to 40 %) whereas experimental studies on fertile peridotite suggest this phase should be exhausted by years. The garnets display systematic trends from ultra-depleted to enriched compositions that have not been recognised in peridotite suites from elsewhere (Gibson et al., 2013). Certain harzburgite members of the xenolith suite contain the first reported occurrence of pyrope garnets with rare-earth element (REE) patterns similar to hypothetical garnets proposed by Stachel et al. (2004) to have formed in the Earth's SCLM during the Archean, prior to metasomatism. These rare ultra-depleted low-Cr garnets occur in low temperature (~1050 oC) xenoliths derived from depths of ~120 km and coexist in chemical and textural equilibrium with highly-refractory olivine (Fo95.4) and orthopyroxene (Mg#=96.4). These phases are all more magnesian than generally encountered in global samples of depleted mantle, i.e. harzburgites and diamond inclusion suites. The Tanzanian ultra-depleted garnets form interconnecting networks ('necklaces') around grains of orthopyroxene, which is of key importance to their origin. This close spatial relationship of garnet and orthopyroxene together with the major, trace and REE contents of the ultra-depleted garnets, are consistent with an origin by isochemical exsolution. The significance of ultra-depleted low-Cr garnets has not previously been recognised in global suites of mantle xenoliths or diamond inclusions: they appear to have been overlooked, primarily

Evidence for distillation in the formation of HAL and related hibonite inclusions. [from Allende, Dhajala, and Murchison chondrites

Science.gov (United States)

Ireland, Trevor R.; Zinner, Ernst K.; Fahey, Albert J.; Esat, Tezer M.

1992-01-01

New Ca- and Ti-isotopic analyses of DH-H1, 7-404, and 7-971, and Mg-isotopic analyses on DH-H1 and 7-404 are reported. O-isotopic analyses of HAL, 7-404, 7-971, and a variety of other refractory inclusions from Murchison were made in order to establish the presence or absence of FUN O-isotopic systematics. A higonite-rich residue produced by the evaporation of kaersutite was analyzed for its trace-element and isotopic abundances to see if any of the characteristics of FUN hibonite inclusions can be produced by distillation in the laboratory. These data are then used to evaluate for all four inclusions the HAL-type formation models originally proposed by Allen et al. (1980) and Lee et al. (1980). The four inclusions were found to have very similar chemical and isotopic features. All are characterized by large Ce depletions and very low Mg, Ti, and V concentrations compared to other meteoritic hibonites. All four inclusions have delta(C-48) within error of -5 per mil. Ca-, Ti-, and O-isotopic compositions are fractionated with enrichments of the heavy isotopes, and the Ti-isotopic mass fractionation is inversely correlated with Ti concentration. It is concluded that the inclusions formed primarily as distillation residues in accord with the early conclusions.

Brentuximab Vedotin Treatment for Primary Refractory Hodgkin Lymphoma

Directory of Open Access Journals (Sweden)

Hung-Bo Wu

2013-01-01

Full Text Available Up to 40% of patients with advanced Hodgkin lymphoma (HL become refractory or relapsed after current standard chemotherapy, among which primary refractory HL confers a particularly poor outcome. With intensive salvage chemotherapy and autologous stem cell transplantation, the long-term remission rate for these patients was only 30%, but more selective treatments with higher therapeutic index are needed. We report the experience of using a new anti-CD30 immunotoxin, brentuximab vedotin, in salvage treatment of a 30-year-old woman with primary refractory Hodgkin lymphoma. The patient presented with SVC syndrome due to the bulky mediastinal tumor and was confirmed to have classical Hodgkin lymphoma, nodular sclerosis type, stage IIIA. The tumor responded to induction chemotherapy transiently, but local progression was noted during subsequent cycles of treatment. Salvage radiotherapy to the mediastinal tumor, obtained no remission but was followed by rapid in-field progression and then lung metastasis. She declined stem cell transplantation and received salvage brentuximab vedotin (BV therapy, which induced dramatic shrinkage of tumor without significant side effects. Serial followup of PET/CT imaging confirmed a rapid and continuous complete remission for 12 months. Although durability of the remission needs further observation, this case illustrates the excellent efficacy of brentuximab vedotin in primary refractory Hodgkin lymphoma.

Convergent J-matrix calculation of the Poet-Temkin model of electron-hydrogen scattering

International Nuclear Information System (INIS)

Konovalov, D.A.; McCarthy, I.E.

1994-01-01

It is shown that the Poet-Temkin model of electron-hydrogen scattering could be solved to any required accuracy using the J-matrix method. The convergence in the basis size is achieved to an accuracy of better than 2% with the inclusion of 37 basis L 2 functions. Previously observed pseudoresonances in the J-matrix calculation naturally disappear with an increase in basis size. No averaging technique is necessary to smooth the convergent J-matrix results. (Author)

Testing of the melter lid refractory for the West Valley Demonstration Project (WVDP)

International Nuclear Information System (INIS)

Gupta, A.; Jain, V.; Mahoney, J.L.; Holman, T.M.

1991-01-01

Monofrax H and Mulfrax 202 refractory were tested for potential application as the melter lid refractory for the WVDP. Resistance to spalling and corrosion by the slurry and offgas salts were primary criteria for selection. Test specimens were subjected to thermal cycling between 450 and 1,100C for five weeks. Visual examination indicated some corrosion but no spalling. SEM/EDS analysis was performed to determine the glass/refractory interface corrosion mechanism. The refractory selection basis will be discussed

Low carbon content and carbon-free refractory materials with high thermal shock resistance; Thermoschockbestaendige feuerfeste Erzeugnisse mit geringerem Kohlenstoffgehalt bzw. kohlenstofffreie Erzeugnisse

Energy Technology Data Exchange (ETDEWEB)

Brachhold, Nora; Aneziris, C.G.; Stein, Volker; Roungos, Vasileios; Moritz, Kirsten [TU Bergakademie Freiberg (TUBAF) (DE). Inst. fuer Keramik, Glas- und Baustofftechnik (IKGB)

2012-07-01

Carbon bonded refractories are essential for steelmaking due to their excellent thermal shock resistance. The research on carbon reduced and carbon-free materials is necessary to manufacture high quality stainless steels tending carbon pick-up in contact to conventional refractory materials. Further advantages are reduced emissions of CO{sub 2} and energy saving potentials due to better heat insulation properties. The challenge is to develop alternative materials with lower carbon contents but with the necessary thermal shock resistance. The Priority Programme 1418 funded by the German Research Foundation (DFG) concentrates on this problem. In this article two materials are presented. First, the carbon content could be reduced by nanoscaled additives resulting in better bonding between matrix and oxidic components. Second, an AL{sub 2}O{sub 3}-rich carbon-free material is presented showing a very good thermal shock resistance due to its designed microstructure. Finally, a steel casting simulator is introduced to test the new materials under nearly real conditions. (orig.)

Effectiveness of botulinum toxin A in treatment of refractory erythromelalgia

Directory of Open Access Journals (Sweden)

Kuan-Hsiang Lin

2013-05-01

Full Text Available Erythromelalgia is characterized by intense burning pain, erythema, and heat in affected areas after precipitating factors such as warm temperature or stress. It is refractory to treatment in some situations. We describe a woman with adenosquamous cell carcinoma of the lung and medically refractory erythromelalgia. The symptoms of erythromelalgia presented as refractory to any medical treatment. Due to the unresponsive nature of her condition, botulinum toxin type A (onabotulinumtoxin A was injected over both of her cheeks, periodically for six cycles. Her symptoms responded dramatically to subcutaneous and intradermal injection of botulinum toxin type A. Repetitive injection demonstrated consistent and reproducible responses, and the efficacy was maintained for approximately 1 month. No adverse effects or complications were noted. Botulinum toxin type A might be safe and effective as an alternative treatment for refractory erythromelalgia, but further large-scale studies are required.

Theoretical and practical aspects about corrosion of refractories used in steel metallurgy: part 3: characterization of commercial refractories; Aspectos teoricos e praticos sobre a corrosao de refratarios utilizados na metalurgia: caracterizacao de refratarios comerciais

Energy Technology Data Exchange (ETDEWEB)

Braganca, S.R., E-mail: saulorb@ufrgs.br [Universidade Federal do Rio Grande Sul (DEMAT/UFRGS), RS (Brazil)

2012-07-01

In this study, it was reviewed the main aspects found in the literature about refractories corrosion, evaluating the feasibility of certain tests and relating them with experimental results. The physical properties and microstructure of commercial refractories were analyzed, considering the differences between them and the quality implications and probable life of the refractory. Thus, it was studied the various types of refractories used as lining on steel ladle. Magnesia-carbon and doloma-carbon refractories were analyzed, highlighting the differences between them. The examined refractory showed characteristics favoring high resistance to corrosion process, presenting a series of properties to be selected in accordance with industry practice. (author)

Interventional embolization for refractory hyperthyroidism

International Nuclear Information System (INIS)

Jiang Guomin; Zhang Yunping; Chen Yaxian; Zhao Jinwei; Yang Weihuai; Chen Jinluo

2001-01-01

Objective: To evaluate the clinical effects of the thyroid artery embolization for refractory hyperthyroidism. Methods: Super selective catheterization and interventional embolization of thyroid superior and inferior arteries were performed with PVA microspheres and Gelfoam particles. Changes of function and size of thyroid were investigated after embolization. Results: The procedures were succeeded in all 21 patients. Followed up by 3-12 months, serum level of thyroid hormones dropped significantly (median FT 3 from 17.1 pmol/L to 7.44 pmol/L, median FT 4 from 51.1 pmol/L to 23.3 pmol/L, P< 0.01). The size of thyroid glands decreased remarkably. Symptoms of hyperthyroidism were controlled in 4 patients and were effectively controlled through low dose antithyroid medication in 17 patients. No serious complications occurred. Conclusions: Thyroid artery embolization is a new safe and effective method for refractory hyperthyroidism

Efficacy of infliximab in refractory posterior uveitis in Behcet's disease patients

OpenAIRE

Ayman K. El Garf; Amira A. Shahin; Sherif A. Shawky; Mohammed A. Azim; Dina A. Effat; Sherry K. Abdelrahman

2018-01-01

Aim of the work: Ocular manifestations are the main cause of morbidity in Behcet's disease (BD). Infliximab (IFX), a chimeric monoclonal antibody directed against tumor necrosis factor-alpha, may be efficient in refractory uveitis due to BD. The aim of this study was to assess the efficacy and safety of IFX in the treatment of patients with BD-associated refractory posterior uveitis (PU). Patient and Methods: Twenty patients with refractory Behcet's PU received IFX therapy as intravenous infu...

Ketogenic diet in 3 cases of childhood refractory status epilepticus

DEFF Research Database (Denmark)

Sort, Rune; Born, Alfred P; Pedersen, Karen N.

2013-01-01

Refractory status epilepticus (RSE) in children is associated with a significant risk of death or neurological morbidity. Recently attention has been drawn to the ketogenic diet (KD) as an acute treatment, as it has shown promise in controlling seizures in otherwise refractory status epilepticus...

Perspectives on environmental protection of refractory metals

International Nuclear Information System (INIS)

Perking, R.A.

1992-01-01

Alloys of refractory metals which combine high strength to weight ratios with useful low-temperature toughness and ductility have been designed to meet the requirements for the next generation of high-temperature aerospace structural materials with one exception: long term resistance to oxidation. It is considered unlikely that refractory metal alloys can be modified to possess useful resistance to oxidation as bulk materials or that coating can be designed to provide high reliability fail-safe protection for the structural alloys developed to date. Recent developments indicate that bulk alloys of W and Mo can be designed to possess short term resistance to oxidation, providing a base material which can be coated to extend useful life with fail-safe protection in the event of random coating failures. Current research on silicide coatings indicates that significant improvements in coating reliability and performance also are feasible. The technical basis for these conclusions is presented in this paper and the direction of future work that could lead to environmentally stable refractory metal alloy/coating systems is discussed

Super Refractory Status Epilepticus

African Journals Online (AJOL)

user

et al did retrospective cohort study from 1 January st. 1994 to 31 March 1998 at Presbyterian Medical. Centre in Columbia, to determine the frequency, risk factors and impact on the outcome of RSE. They found out that 69% of seizures recurred after. Key Words: Super refractory status epilepticus, Zambia. Medical Journal of ...

Process technology - rare and refractory metals

International Nuclear Information System (INIS)

Gupta, C.K.; Bose, D.K.

1989-01-01

India has fairly rich resreves of rare and refractory metals. Abundant sources of ilmenite, rutile, zircon and rare earths are found in the placer deposits of the southern and eastern coasts of the country. Columbite-tantalite occur in mica and the mining belts of Bihar and cassiterite deposits are found in Bastar (Madhya Pradesh). Vanadium as a minor associate occurs in bauxites and in the vast deposits of titaniferrous magnetites. Over the years, research and development and pilot plant works in many research organisations in India have built up a sound technological base in the country for process metallurgy of many refractory and rare earth metals starting from their indigenous sources. The present paper provides a comprehensive view of the developments that have taken place till now on the processing of various refractory and rare earth metals with particular reference to the extensive work carried out at the Department of Atomic Energy. The coverage includes mineral benification separation of individual elements, preparation of pure intermediates, techniques of reduction to metal and final purification. The paper also reviews some of the recent developments that have been taken place in these fields and the potential application of these metals in the foreseeable future. (author). 22 refs., 18 fi g., 7 tabs

Reuse of ultrafine mineral wool production waste in the manufacture of refractory concrete.

Science.gov (United States)

Stonys, R; Kuznetsov, D; Krasnikovs, A; Škamat, J; Baltakys, K; Antonovič, V; Černašėjus, O

2016-07-01

The paper deals with the mineral wool production waste (cupola dust - CD), presents CD characterization and aims to reuse CD in production of refractory concrete with calcium aluminate cement. The study of CD covers its chemical, phase and thermal analyses along with the morphological study and determination of particles size distribution. Zeta-potential, electrical conductivity and pH values of CD suspension are presented in the paper as well. Commercial microsilica additive in refractory concrete has been replaced with cupola dust. Compositions of refractory concrete have been prepared by incorporating 1%, 2% and 3% of CD. The bulk density, ultrasonic wave velocity, cold crushing strength and thermal shock resistance of the created refractory concrete have been determined. Based on experimental results, it has been found that cupola dust may be used for the production of refractory concrete. The environmental impact related to the CD reuse in refractory concrete production has been evaluated as well. Copyright © 2016 Elsevier Ltd. All rights reserved.

Deformation and fracture properties of metals with non-metallic inclusions; Verformung und Bruch von Metallen mit nichtmetallischen Einschluessen

Energy Technology Data Exchange (ETDEWEB)

Schmauder, S.; Soppa, E. [Stuttgart Univ. (Germany). Staatliche Materialpruefungsanstalt

1998-12-31

Microstructural effects due to formation of non-uniform lines of non-metallic inclusions in the matrix are examined with respect to their macro-, meso-, and micromechanical effects in the alloy Al(6061) reinforced by SiC inclusions. A comparative analysis of results obtained with various microstructures reveals essential differences in the formation of shear bands, stress peaks, and strain concentrations in the material structure. The maxima and the distribution of those field variables are determined not only by the arrangement of inclusions clusters in the stringers but also depend on the presence and number of single-particle inclusions in pure matrix material. The banding of the microstructure causes a strongly anisotropic behaviour in terms of stress and strain distributions. (orig./CB) [Deutsch] In diesem Beitrag werden Gefuegeeinfluesse aufgrund unterschiedlich starker zeiliger Anordnungen der Teilchen in der Matrix im Hinblick auf ihre makro-, meso- und mikromechanischen Auswirkungen am Beispiel einer SiC-teilchenverstaerkten Aluminiumlegierung Al(6061) untersucht. Ein Vergleich der Ergebnisse verschiedener Gefuege zeigt wesentliche Unterschiede hinsichtlich der Ausbildung von Scherbaendern, Spannungsspitzen und von Dehnungskonzentrationen im Werkstoffgefuege. Die Maxima und die Verteilung dieser Feldgroessen sind nicht nur abhaengig davon, wie die Teilchen in den Zeilen angeordnet sind, sondern auch davon, ob einzelne Teilchen in reinen Matrixbereichen vorhanden sind. Die Zeiligkeit des Gefueges fuehrt zu einem stark anisotropen Verhalten hinsichtlich Spannungs- und Dehnungsverteilungen. (orig.)

When myasthenia gravis is deemed refractory: clinical signposts and treatment strategies

Science.gov (United States)

Mantegazza, Renato; Antozzi, Carlo

2018-01-01

The prognosis for patients with myasthenia gravis (MG) has improved significantly over the past half century, including substantial reductions in mortality and morbidity. However, approximately 10% of patients fails to respond adequately to current therapies and are considered treatment refractory, or treatment intolerant, and up to 80% have disease that fails to achieve complete stable remission. Although patients with autoantibodies to muscle-specific tyrosine kinase (anti-MuSK positive) are more likely to become treatment refractory than those with autoantibodies to the acetylcholine receptor (anti-AChR positive), each of these serotypes is substantially represented in the refractory MG population. Other risk factors for becoming treatment refractory include history of thymoma or thymectomy and female sex. A modified treatment algorithm for MG is proposed: patients who have disease that fails to respond to the stepwise approach to therapy, are treatment intolerant, or who require chronic rescue measures despite ongoing therapy, should be considered treatment refractory and emerging therapies should be considered. Three emerging monoclonal antibody-based therapies are discussed: the anti-B-cell agent rituximab; the terminal complement activation inhibitor eculizumab; and belimumab, which targets B-cell activating factor. Increased understanding of molecular pathophysiology and accurate antibody subtyping in MG should lead to the use of new therapeutic agents and successful management of treatment-refractory patients. PMID:29403543

Refractory organic substances in the environment

National Research Council Canada - National Science Library

Frimmel, F. H

2002-01-01

... and its Quality Control in Fractions of Refractory Organic Substances and the Corresponding Original Water Samples 39 Introduction 39 Description of Analytical Methods 41 Sample Treatment 41 Fl...

Evaluation of Alternative Refractory Materials for the Main Flame Deflectors at KSC Launch Complexes

Science.gov (United States)

Calle, Luz Marina; Trejo, David; Rutkowsky, Justin

2006-01-01

The deterioration of the refractory materials used to protect the KSC launch complex steel base structures from the high temperatures during launches results in frequent and costly repairs and safety hazards. KSC-SPEC-P-0012, Specification for Refractory Concrete, is ineffective in qualifying refractory materials. This study of the specification and of alternative refractory materials recommends a complete revision of the specification and further investigation of materials that were found to withstand the environment of the Solid Rocket Booster main flame deflector better than the refractory materials in current use in terms of compressive strength, tensile strength, modulus of rupture, shrinkage, and abrasion.

Ultrastructure of inclusion bodies in annulus cells in the degenerating human intervertebral disc.

Science.gov (United States)

Gruber, H E; Hanley, E N

2009-06-01

The rough endoplasmic reticulum (rER) of the cell has an architectural editing function that checks whether protein structure and three-dimensional assembly have occurred properly prior to export of newly synthesized material out of the cell. If these have been faulty, the material is retained within the rER as an inclusion body. Inclusion bodies have been identified previously in chondrocytes and osteoblasts in chondrodysplasias and osteogenesis imperfecta. Inclusion bodies in intervertebral disc cells, however, have only recently been recognized. Our objectives were to use transmission electron microscopy to analyze more fully inclusion bodies in the annulus pulposus and to study the extracellular matrix (ECM) surrounding cells containing inclusion bodies. ECM frequently encapsulated cells with inclusion bodies, and commonly contained prominent banded aggregates of Type VI collagen. Inclusion body material had several morphologies, including relatively smooth, homogeneous material, or a rougher, less homogeneous feature. Such findings expand our knowledge of the fine structure of the human disc cell and ECM during disc degeneration, and indicate the potential utility of ultrastructural identification of discs with intracellular inclusion bodies as a screening method for molecular studies directed toward identification of defective gene products in degenerating discs.

Corundum-Hibonite Inclusions and the Environments of High Temperature Processing in the Early Solar System

Science.gov (United States)

Needham, A. W.; Messenger, S.

2013-01-01

Calcium, Aluminum-rich inclusions (CAIs) are composed of the suite of minerals predicted to be the first to condense from a cooling gas of solar composition [1]. Yet, the first phase to condense, corundum, is rare in CAIs, having mostly reacted to form hibonite followed by other phases at lower temperatures. Many CAIs show evidence of complex post-formational histories, including condensation, evaporation, and melting [e.g. 2, 3]. However, the nature of these thermal events and the nebular environments in which they took place are poorly constrained. Some corundum and corundum-hibonite grains appear to have survived or avoided these complex CAI reprocessing events. Such ultra-refractory CAIs may provide a clearer record of the O isotopic composition of the Sun and the evolution of the O isotopic composition of the planet-forming region [4-6]. Here we present in situ O and Mg isotopic analyses of two corundum/hibonite inclusions that record differing formation histories.

Digital Technology in Education: Towards New Inclusive Practices

DEFF Research Database (Denmark)

Jönsson, Lise Høgh

for new inclusive practices. The main theoretical argument derives from the work of French sociologist Pierre Bourdieu. Bourdieu argues that we act upon the world with our habitus, i.e. dispositions created due to previous experiences working as a matrix of perceptions, assumptions and actions....... Using Bourdieu’s theoretical framework, it becomes possible to explain how children and people with learning disabilities are able to strengthen their position by the use of digital technology. This theoretical framework is enhanced by theories of empowerment as any improvement in the participation...... and decision-making power, hold the potential to change opportunity structures in an inclusive direction . Research was carried out in kindergartens and special education facilities in Denmark. Building upon design-based research, the research aimed at testing and developing approaches to digital technology...

Therapeutic burst-suppression coma in pediatric febrile refractory status epilepticus.

Science.gov (United States)

Lin, Jainn-Jim; Chou, Cheng-Che; Lan, Shih-Yun; Hsiao, Hsiang-Ju; Wang, Yu; Chan, Oi-Wa; Hsia, Shao-Hsuan; Wang, Huei-Shyong; Lin, Kuang-Lin

2017-09-01

Evidence for the beneficial effect of therapeutic burst-suppression coma in pediatric patients with febrile refractory status epilepticus is limited, and the clinical outcomes of this treatment strategy are largely unknown. Therefore, the aim of this study was to explore the outcomes of therapeutic burst-suppression coma in a series of children with febrile refractory status epilepticus. We retrospectively reviewed consecutive pediatric patients with febrile refractory status epilepticus admitted to our pediatric intensive care unit between January 2000 and December 2013. The clinical characteristics were analyzed. Thirty-five patients (23 boys; age range: 1-18years) were enrolled, of whom 28 (80%) developed super-refractory status epilepticus. All of the patients received the continuous administration of intravenous antiepileptic drugs for febrile refractory status epilepticus, and 26 (74.3%) achieved therapeutic burst-suppression coma. All of the patients received mechanical ventilatory support, and 26 (74.3%) received inotropic agents. Eight (22.9%) patients died within 1month. The neurologically functional outcomes at 6months were good in six (27.3%) of the 22 survivors, of whom two returned to clinical baseline. The patients with therapeutic burst-suppression coma were significantly associated with hemodynamic support than the patients with electrographic seizures control (p=0.03), and had a trend of higher 1-month mortality rate, worse 6months outcomes, and a longer duration of hospitalization. Our results suggest that therapeutic burst-suppression coma to treat febrile refractory status epilepticus may lead to an increased risk of hemodynamic instability and a trend of worse outcomes. Copyright © 2017 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Zirconium determination in refractories (gravimetric method)

International Nuclear Information System (INIS)

Capiotto, N.; Narahashi, Y.; Perish, P.G.; Souza, J.R. de

1991-01-01

A gravimetric method for zirconium determination in refractories is described. X-ray fluorescence analysis is also employed in this experiment and considerations about interfering elements are presented. (M.V.M.)

Development of various welding techniques for refractory and reactive metals and alloys

International Nuclear Information System (INIS)

Tonpe, Sunil; Saibaba, N.

2016-01-01

Nuclear Fuel Complex (NFC), Hyderabad, India with its excellent manufacturing facilities, produces nuclear fuel and structural components for nuclear reactors. NFC has taken up the challenging job of production of various critical components made out of refractory and reactive metals and alloys for nuclear and aerospace applications as an indigenization import substitute program. Refractory metals are prime candidates for many high temperature aerospace components because of refractory metal's high melting points and inherent creep resistance. The use of refractory metals is often limited because of their poor room temperature properties, inadequate oxidation resistance at elevated temperatures, difficulties associated with joining or welding etc. These advanced materials demand stringent requirement with respect to chemistry, dimensional tolerances, mechanical and metallurgical properties. This paper discusses in detail various welding techniques adopted in NFC for refractory and reactive metals and alloys such as Nb, Zr, Ti, Ta, Zircaloy, Titanium-half alloy etc. to manufacture various components and assemblies required for nuclear and aerospace applications

Applications of radioisotopes for studying refractory wear-out in Bhilai Steel Plant

International Nuclear Information System (INIS)

Dubey, R.S.; Bose, U.P.; Shipstone, A.J.

1979-01-01

In Bhilai Steel Plant, investigations were carried out to study the refractory wear-out of (i) hearth bottom of blast furnaces, (ii) roof of open hearth furnaces, and (iii) hot metal mixer lining, by using radioisotope tracer techniques with a view to evaluate the life of the refractory lining at various locations and to help in planning its timely hot and cold repairs. The life of the refractory lining has the effective bearing on the overall production and hence on the economy of the plant. The two radiometric methods employed for studying the erosion of the refractory lining, by using isotope inserted bricks at various positions without damaging the lining are (i) based on recording the penetration of gamma rays emitting from the radioactive isotopes inserted at definite points of the brick lining and, (ii) by detecting the radioactivity of the pig iron or steel arising due to washing away of the respective radioactive isotopes previously inserted in the lining. In hot mixers also radioisotope sources were placed in the critical location of refractory lining and the washing out of radioisotope due to refractory brick wear out was detected by radiogauging at site. It has been found that radiotracer technique with periodic radiogauging is very useful method for tracing the radioisotope source if more than one refractory brick with isotope is placed, as in the case of open hearth furnaces. The results of radioanalysis revealed that radioactivity coming alongwith hot metal steel has been far below the permissible limit of concentration i.e. 20 micro-curie per ton of metal. Further, during dismantling of the residual refractory lining of open hearth furnaces or hot metal mixers, bricks containing radioisotopes have been successfully retrieved for safe disposal. (auth.)

Fragmentation process of vitrified ceramic waste (VCW) aiming its incorporation in silico-aluminous refractory concrete for production of refractory bricks

International Nuclear Information System (INIS)

Gomes, L.B.; Brandalise, R.N.; Santos, V. dos; Bergmann, C.P.

2012-01-01

Ceramic industry generates large amounts of waste, usually disposed in landfills. Reuse could minimize their generation and provides sustainable solutions. However, the energy cost of grinding these waste becomes a hindrance to their reuse. This work aims to obtain particle sizes of vitrified ceramic waste (VCW) using a fast, efficient and low cost fragmentation process as well as its use in refractory concrete. The results shows a wide range of particle size of VCW, which can be used as a promising source of raw material for production of refractory concrete. (author)

Depression in patients with refractory temporal lobe epilepsy

Directory of Open Access Journals (Sweden)

Eleonora Borges Gonçalves

2011-10-01

Full Text Available OBJECTIVE: To evaluate the comorbidity of depressive disorders in patients with refractory temporal lobe epilepsy (TLE. METHOD: We evaluated 25 consecutive patients with refractory TLE (16 women and 9 men, using semi-structured psychiatric interviews, according to the International Classification of Diseases (ICD-10, and the Beck Depression Inventory. RESULTS: Seventeen of 25 patients (68% had depressive disorder: 6 with dysthymia, three with major depressive episodes and 8 with recurrent depressive disorders. Two (8% were diagnosed with mixed anxiety and depression. Only 5 of 17 patients (29.4% were previously diagnosed with depressive disorder and received prior antidepressant treatment. Duration of epilepsy was significantly higher in patients with depressive disorder (p=0.016, but there was no relationship between depression and seizure frequency. CONCLUSION: This study confirmed that depressive disorders are common and underdiagnosed in patients with TLE refractory to AEDs. Patients with longer duration of epilepsy are at higher risk of having depression.

Measurement of |Vub| from Inclusive Charmless Semileptonic B Decays

International Nuclear Information System (INIS)

Urquijo, P.; Barberio, E.; Limosani, A.; Sevior, M. E.; Taylor, G. N.; Wedd, R.; Adachi, I.; Dalseno, J.; Haba, J.; Itoh, R.; Katayama, N.; Krokovny, P.; Nakao, M.; Nishida, S.; Nozaki, T.; Ozaki, H.; Sakai, Y.; Sumisawa, K.; Trabelsi, K.; Uehara, S.

2010-01-01

We present the partial branching fraction for inclusive charmless semileptonic B decays and the corresponding value of the Cabibbo-Kobayashi-Maskawa matrix element |V ub |, using a multivariate analysis method to access ∼90% of the B→X u lν phase space. This approach dramatically reduces the theoretical uncertainties from the b-quark mass and nonperturbative QCD compared to all previous inclusive measurements. The results are based on a sample of 657x10 6 BB pairs collected with the Belle detector. We find that ΔB(B→X u lν;p l *B >1.0 GeV/c)=1.963x(1±0.088 stat ±0.081 syst )x10 -3 . Corresponding values of |V ub | are extracted using several theoretical calculations.

Radioimmunotherapy in refractory b-cell nonhodgkins lymphoma with I-131-labeled chimeric anti cd-20 c2b8 (I-131 rituximab): preliminary result

International Nuclear Information System (INIS)

Kang, Hye Jin; Park, Yeon Hee; Kim, Sung Eun and others

2005-01-01

Recently, the native chimeric human-mouse anti CD-20 antibody IDEC-C2B8 (Rituximab) has been widely applied in NHL. This ongoing phase study was to evaluate whether radioimmunotherapy (RIT) with I-131 rituximab is effective in refractory B-cell NHL. Inclusion criteria were as follows: B-cell NHL with relapsed or refractory to primary standard therapy, measurable disease, adequate hematologic, renal, and hepatic function, informed consent. The rituximab (Mabthera, Roach) was radiolabeled with iodine-131(I-131) using a modified chloramine T method with high radiochemical purity (95%) and preservation of immuno-reactivity. All patients received loading doses of unlabeled rituximab (median, 40 mg: range, 20∼70 mg) immediately prior to administration of therapeutic dose (51.4∼152.2 MBq/kg), and then underwent gamma camera scan. 11 patients were enrolled (4 low-grade B-cell NHL, 7 DLBCL, median age 63 years). Patients had received a median of three prior chemotherapy regimens. The objective response rate was 36.4% (1 CR, 3 PRs). These all responses were observed in low-grade B-cell NHL, except one with DLBCL. Adverse events were primarily hematologic toxicities; the incidence of grade 3/4 neutropenia, thrombocytopenia, and anemia was 27.3%, 45.5%, and 18.2%, respectively. The treatment-related mortality was observed in one patient, who had been previously treated with high-dose chemotherapy plus TBI with autologous stem cell transplantation. RIT with I-131 rituximab seems to be effective tolerable in refractory low-grade B-cell NHL, although modest activity in refractory DLBCL. Further studies to define the efficacy of I-131 rituximab in DLBCL are warranted

Radioimmunotherapy in refractory b-cell nonhodgkins lymphoma with I-131-labeled chimeric anti cd-20 c2b8 (I-131 rituximab): preliminary result

Energy Technology Data Exchange (ETDEWEB)

Kang, Hye Jin; Park, Yeon Hee; Kim, Sung Eun and others [Korea University Medical School, Seoul (Korea, Republic of)

2005-07-01

Recently, the native chimeric human-mouse anti CD-20 antibody IDEC-C2B8 (Rituximab) has been widely applied in NHL. This ongoing phase study was to evaluate whether radioimmunotherapy (RIT) with I-131 rituximab is effective in refractory B-cell NHL. Inclusion criteria were as follows: B-cell NHL with relapsed or refractory to primary standard therapy, measurable disease, adequate hematologic, renal, and hepatic function, informed consent. The rituximab (Mabthera, Roach) was radiolabeled with iodine-131(I-131) using a modified chloramine T method with high radiochemical purity (95%) and preservation of immuno-reactivity. All patients received loading doses of unlabeled rituximab (median, 40 mg: range, 20{approx}70 mg) immediately prior to administration of therapeutic dose (51.4{approx}152.2 MBq/kg), and then underwent gamma camera scan. 11 patients were enrolled (4 low-grade B-cell NHL, 7 DLBCL, median age 63 years). Patients had received a median of three prior chemotherapy regimens. The objective response rate was 36.4% (1 CR, 3 PRs). These all responses were observed in low-grade B-cell NHL, except one with DLBCL. Adverse events were primarily hematologic toxicities; the incidence of grade 3/4 neutropenia, thrombocytopenia, and anemia was 27.3%, 45.5%, and 18.2%, respectively. The treatment-related mortality was observed in one patient, who had been previously treated with high-dose chemotherapy plus TBI with autologous stem cell transplantation. RIT with I-131 rituximab seems to be effective tolerable in refractory low-grade B-cell NHL, although modest activity in refractory DLBCL. Further studies to define the efficacy of I-131 rituximab in DLBCL are warranted.

Plasma deposition of refractories

International Nuclear Information System (INIS)

Kudinov, V.V.; Ivanov, V.M.

1981-01-01

The problems of deposition, testing and application of plasma coating of refractory metals and oxides are considered. The process fundamentals, various manufacturing procedures and equipment for their realization are described in detail. Coating materials are given (Al, Mg, Al 2 O 3 , ZrO 2 , MgAlO 4 ) which are used in reactor engineering and their designated purposes are shown [ru

Social inclusion and inclusive education

Directory of Open Access Journals (Sweden)

Marsela Robo

2014-07-01

In line with global debate on social inclusion and exclusion, the author brings the way this debate has now pervaded both the official and development policy discourse in Albania.Social inclusion is considered as one of the priorities of the current government, with poverty reduction as its main focus, which will be ensured not only through economic development. In the end, the article focuses on the role of education as a very important and useful tool for ensuring social inclusion.Social inclusion through education, in particular through vocational education, considered by the author as the only way towards sustainable development of Albanian society.

Barrier Coatings for Refractory Metals and Superalloys

Energy Technology Data Exchange (ETDEWEB)

SM Sabol; BT Randall; JD Edington; CJ Larkin; BJ Close

2006-02-23

In the closed working fluid loop of the proposed Prometheus space nuclear power plant (SNPP), there is the potential for reaction of core and plant structural materials with gas phase impurities and gas phase transport of interstitial elements between superalloy and refractory metal alloy components during service. Primary concerns are surface oxidation, interstitial embrittlement of refractory metals and decarburization of superalloys. In parallel with kinetic investigations, this letter evaluates the ability of potential coatings to prevent or impede communication between reactor and plant components. Key coating requirements are identified and current technology coating materials are reviewed relative to these requirements. Candidate coatings are identified for future evaluation based on current knowledge of design parameters and anticipated environment. Coatings were identified for superalloys and refractory metals to provide diffusion barriers to interstitial transport and act as reactive barriers to potential oxidation. Due to their high stability at low oxygen potential, alumina formers are most promising for oxidation protection given the anticipated coolant gas chemistry. A sublayer of iridium is recommended to provide inherent diffusion resistance to interstitials. Based on specific base metal selection, a thin film substrate--coating interdiffusion barrier layer may be necessary to meet mission life.

Barrier Coatings for Refractory Metals and Superalloys

International Nuclear Information System (INIS)

SM Sabol; BT Randall; JD Edington; CJ Larkin; BJ Close

2006-01-01

In the closed working fluid loop of the proposed Prometheus space nuclear power plant (SNPP), there is the potential for reaction of core and plant structural materials with gas phase impurities and gas phase transport of interstitial elements between superalloy and refractory metal alloy components during service. Primary concerns are surface oxidation, interstitial embrittlement of refractory metals and decarburization of superalloys. In parallel with kinetic investigations, this letter evaluates the ability of potential coatings to prevent or impede communication between reactor and plant components. Key coating requirements are identified and current technology coating materials are reviewed relative to these requirements. Candidate coatings are identified for future evaluation based on current knowledge of design parameters and anticipated environment. Coatings were identified for superalloys and refractory metals to provide diffusion barriers to interstitial transport and act as reactive barriers to potential oxidation. Due to their high stability at low oxygen potential, alumina formers are most promising for oxidation protection given the anticipated coolant gas chemistry. A sublayer of iridium is recommended to provide inherent diffusion resistance to interstitials. Based on specific base metal selection, a thin film substrate--coating interdiffusion barrier layer may be necessary to meet mission life

Prognostic Factors for Refractory Status Epilepticus

Directory of Open Access Journals (Sweden)

J. Gordon Millichap

2013-03-01

Full Text Available Researchers at the Mayo Clinic, Rochester, MN studied the outcome and identified prognostic factors for refractory status epilepticus (RSE in 54 adult patients, median age 52 years [range 18-93].

Studies on the optimization of deformation processed metal metal matrix composites

Energy Technology Data Exchange (ETDEWEB)

Ellis, Tim W. [Iowa State Univ., Ames, IA (United States)

1994-01-04

A methodology for the production of deformation processed metal metal matrix composites from hyper-eutectic copper-chromium alloys was developed. This methodology was derived from a basic study of the precipitation phenomena in these alloys encompassing evaluation of microstructural, electrical, and mechanical properties. The methodology developed produces material with a superior combination of electrical and mechanical properties compared to those presently available in commercial alloys. New and novel alloying procedures were investigated to extend the range of production methods available for these material. These studies focused on the use of High Pressure Gas Atomization and the development of new containment technologies for the liquid alloy. This allowed the production of alloys with a much more refined starting microstructure and lower contamination than available by other methods. The knowledge gained in the previous studies was used to develop two completely new families of deformation processed metal metal matrix composites. These composites are based on immissible alloys with yttrium and magnesium matrices and refractory metal reinforcement. This work extends the physical property range available in deformation processed metal metal matrix composites. Additionally, it also represents new ways to apply these metals in engineering applications.

Refractory disease in autoimmune diseases

NARCIS (Netherlands)

Vasconcelos, Carlos; Kallenberg, Cees; Shoenfeld, Yehuda

Refractory disease (RD) definition has different meanings but it is dynamic, according to knowledge and the availability of new drugs. It should be differentiated from severe disease and damage definitions and it must take into account duration of adequate therapy and compliance of the patient. It

Chemical analysis of refractories by plasma spectrometry

International Nuclear Information System (INIS)

Coutinho, C.A.

1990-01-01

X-ray spectrometry has been, since the last two or three decades, the traditional procedure for the chemical analysis of refractories, due to its high degree of accuracy and speed to produce analytical results. An interesting alternative to X-ray fluorescence is provided by the Inductively Coupled Plasma Spectrometry technique, for those laboratories where wet chemistry facilities are already available or process control is not required at high speed, or investiment costs have to be low. This paper presents results obtained by plasma spectroscopy for the analysis of silico - aluminous refractories, showing calibration curves, precion and detection limits. Considerations and comparisons with X-ray fluorescence are also made. (author) [pt

Improvements in or relating to refractory materials

International Nuclear Information System (INIS)

Peckett, J.W.A.

1980-01-01

A process is described for the production of a refractory material which includes heating an intermediate material containing carbon to cause a thermally induced reaction involving carbon in the intermediate material, wherein the intermediate material has been produced by heating a shaped gel precipitated gel, and the carbon in the intermediate material for participating in the thermally induced reaction has been produced from a gelling agent, or a derivative thereof, incorporated in the gel during gel precipitation. As examples, the refractory material may comprise uranium/plutonium oxide, or uranium/plutonium carbide, or thorium/uranium carbide, or tungsten carbide, or tungsten carbide/cobalt metal. (author)

Development of electro fused aggregates for use in refractories for the burning zone of cement kilns

International Nuclear Information System (INIS)

Ferreira, Luis Leonardo Horne Curimbaba

2006-01-01

Electro fused aggregates are largely used in refractory production due to the better performance reached when they are employed. In this work electro fused aggregates were designed for application in refractories for the burning zone of cement kilns. Initially reaction evaluation was conducted aiming the identification of the most prone refractory systems when single refractory phases react with Portland cement phases at high temperatures. In the next step, raw materials of the best refractory systems were electro fused to generate different aggregate compositions. The electro fused aggregates properties were evaluated and the classified ones were used to produce refractory bricks for the burning zone of cement kilns. General characteristics of these bricks were measured and compared with a standard magnesia-spinel refractory. Aggregates of the system Mg O - TiO 2 - Ca O, more specifically aggregates belonged to the compatibility triangle Mg O - Mg 2 TiO 4 - CaTiO 3 , showed suitable characteristics for development of refractories for the burning zone cement kilns. (author)

Niobium Carbide-Reinforced Al Matrix Composites Produced by High-Energy Ball Milling

Science.gov (United States)

Travessa, Dilermando Nagle; Silva, Marina Judice; Cardoso, Kátia Regina

2017-06-01

Aluminum and its alloys are key materials for the transportation industry as they contribute to the development of lightweight structures. The dispersion of hard ceramic particles in the Al soft matrix can lead to a substantial strengthening effect, resulting in composite materials exhibiting interesting mechanical properties and inspiring their technological use in sectors like the automotive and aerospace industries. Powder metallurgy techniques are attractive to design metal matrix composites, achieving a homogeneous distribution of the reinforcement into the metal matrix. In this work, pure aluminum has been reinforced with particles of niobium carbide (NbC), an extremely hard and stable refractory ceramic. Its use as a reinforcing phase in metal matrix composites has not been deeply explored. Composite powders produced after different milling times, with 10 and 20 vol pct of NbC were produced by high-energy ball milling and characterized by scanning electron microscopy and by X-ray diffraction to establish a relationship between the milling time and size, morphology, and distribution of the particles in the composite powder. Subsequently, an Al/10 pct NbC composite powder was hot extruded into cylindrical bars. The strength of the obtained composite bars is comparable to the commercial high-strength, aeronautical-grade aluminum alloys.

Vascular Canals in Permanent Hyaline Cartilage: Development, Corrosion of Nonmineralized Cartilage Matrix, and Removal of Matrix Degradation Products.

Science.gov (United States)

Gabner, Simone; Häusler, Gabriele; Böck, Peter

2017-06-01

Core areas in voluminous pieces of permanent cartilage are metabolically supplied via vascular canals (VCs). We studied cartilage corrosion and removal of matrix degradation products during the development of VCs in nose and rib cartilage of piglets. Conventional staining methods were used for glycosaminoglycans, immunohistochemistry was performed to demonstrate collagens types I and II, laminin, Ki-67, von Willebrand factor, VEGF, macrophage marker MAC387, S-100 protein, MMPs -2,-9,-13,-14, and their inhibitors TIMP1 and TIMP2. VCs derived from connective tissue buds that bulged into cartilage matrix ("perichondrial papillae", PPs). Matrix was corroded at the tips of PPs or resulting VCs. Connective tissue stromata in PPs and VCs comprised an axial afferent blood vessel, peripherally located wide capillaries, fibroblasts, newly synthesized matrix, and residues of corroded cartilage matrix (collagen type II, acidic proteoglycans). Multinucleated chondroclasts were absent, and monocytes/macrophages were not seen outside the blood vessels. Vanishing acidity characterized areas of extracellular matrix degradation ("preresorptive layers"), from where the dismantled matrix components diffused out. Leached-out material stained in an identical manner to intact cartilage matrix. It was detected in the stroma and inside capillaries and associated downstream veins. We conclude that the delicate VCs are excavated by endothelial sprouts and fibroblasts, whilst chondroclasts are specialized to remove high volumes of mineralized cartilage. VCs leading into permanent cartilage can be formed by corrosion or inclusion, but most VCs comprise segments that have developed in either of these ways. Anat Rec, 300:1067-1082, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Zirconium determination in refractories (gravimetric method)

International Nuclear Information System (INIS)

Capiotto, N.; Narahashi, Y.; Perish, C.G.; Souza, J.R.

1991-01-01

The zirconium determination in refractories is described, consisting in two separation methods for eliminating the interferences. The formatted product is calcined at 1100 0 C and determined gravimetrically as Zr P z 07. (author)

Genetics of refractoriness to Plasmodium falciparum in the mosquito Anopheles stephensi

NARCIS (Netherlands)

Feldmann, A.M.; Gemert, Geert-Jan van; Vegte-Bolmer, Marga G. van de; Jansen, Ritsert C.

1998-01-01

We previously selected a line of the malaria vector mosquito Anopheles stephensi refractory (resistant) to the human malaria parasite Plasmodium falciparum, using in vitro infections with P. falciparum gametocytes. This report presents data on the genetic background of refractoriness. The results of

Productivity Costs in Patients with Refractory Chronic Rhinosinusitis

Science.gov (United States)

Rudmik, Luke; Smith, Timothy L.; Schlosser, Rodney J.; Hwang, Peter H.; Mace, Jess C.; Soler, Zachary M.

2014-01-01

Objective Disease-specific reductions in patient productivity can lead to substantial economic losses to society. The purpose of this study was to: 1) define the annual productivity cost for a patient with refractory chronic rhinosinusitis (CRS) and 2) evaluate the relationship between degree of productivity cost and CRS-specific characteristics. Study Design Prospective, multi-institutional, observational cohort study. Methods The human capital approach was used to define productivity costs. Annual absenteeism, presenteeism, and lost leisure time was quantified to define annual lost productive time (LPT). LPT was monetized using the annual daily wage rates obtained from the 2012 US National Census and the 2013 US Department of Labor statistics. Results A total of 55 patients with refractory CRS were enrolled. The mean work days lost related to absenteeism and presenteeism was 24.6 and 38.8 days per year, respectively. A total of 21.2 household days were lost per year related to daily sinus care requirements. The overall annual productivity cost was $10,077.07 per patient with refractory CRS. Productivity costs increased with worsening disease-specific QoL (r=0.440; p=0.001). Conclusion Results from this study have demonstrated that the annual productivity cost associated with refractory CRS is $10,077.07 per patient. This substantial cost to society provides a strong incentive to optimize current treatment protocols and continue evaluating novel clinical interventions to reduce this cost. PMID:24619604

Productivity costs in patients with refractory chronic rhinosinusitis.

Science.gov (United States)

Rudmik, Luke; Smith, Timothy L; Schlosser, Rodney J; Hwang, Peter H; Mace, Jess C; Soler, Zachary M

2014-09-01

Disease-specific reductions in patient productivity can lead to substantial economic losses to society. The purpose of this study was to: 1) define the annual productivity cost for a patient with refractory chronic rhinosinusitis (CRS) and 2) evaluate the relationship between degree of productivity cost and CRS-specific characteristics. Prospective, multi-institutional, observational cohort study. The human capital approach was used to define productivity costs. Annual absenteeism, presenteeism, and lost leisure time was quantified to define annual lost productive time (LPT). LPT was monetized using the annual daily wage rates obtained from the 2012 U.S. National Census and the 2013 U.S. Department of Labor statistics. A total of 55 patients with refractory CRS were enrolled. The mean work days lost related to absenteeism and presenteeism were 24.6 and 38.8 days per year, respectively. A total of 21.2 household days were lost per year related to daily sinus care requirements. The overall annual productivity cost was $10,077.07 per patient with refractory CRS. Productivity costs increased with worsening disease-specific QoL (r = 0.440; p = 0.001). Results from this study have demonstrated that the annual productivity cost associated with refractory CRS is $10,077.07 per patient. This substantial cost to society provides a strong incentive to optimize current treatment protocols and continue evaluating novel clinical interventions to reduce this cost. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

Analysis on composition and inclusions of ballpoint pen tip steel

Science.gov (United States)

Yang, Qian-kun; Shen, Ping; Zhang, Dong; Wu, Yan-xin; Fu, Jian-xun

2018-04-01

Ballpoint pen tip steel, a super free-cutting stainless steel, exhibits excellent corrosion resistance and good machining properties. In this study, inductively coupled plasma spectroscopy, metallographic microscopy, and scanning electron microscopy were used to determine the elemental contents in five ballpoint pen tips and their components, morphologies, and inclusion distributions. The results showed that the steels were all S-Pb-Te super free-cutting ferritic stainless steel. The free-cutting phases in the steels were mainly MnS, Pb, and small amounts of PbTe. MnS inclusions were in the form of chain distributions, and the aspect ratio of each size inclusion in the chain was small. The stress concentration effect could substantially reduce the cutting force when the material was machined. Some of the Pb was distributed evenly in the steel matrix as fine particles (1-2 μm), and the rest of the Pb was distributed at the middle or at both ends of the MnS inclusions. The Pb plays a role in lubrication and melting embrittlement, which substantially increases the cutting performance. PbTe was also usually distributed in the middle and at both ends of the MnS inclusions, and Te could convert the sulfides into spindles, thereby improving the cutting performance of the steel.

Felbamate in an adult population with severe refractory epilepsy.

LENUS (Irish Health Repository)

Kearney, H

2011-04-05

Felbamate (FBM) is efficacious in treating patients with refractory epilepsy but was withdrawn due to cases of aplastic anaemia, hepatic failure and five reported deaths. FBM is currently used in specialist centres and is only being used in one Irish centre to date. This papers aim is to review the efficacy and safety experience of FBM in Irish adult patients with refractory epilepsy. A retrospective chart review was done on patients\\' medical records. Patients were subdivided into responders and non responders based on change in seizure frequency and side effects were recorded for all. Of the 13 patients on FBM nine patients responded to FBM, four patients did not. FBM is a safe and efficacious alternative in an Irish adult population with refractory epilepsy. However close monitoring is still required given the potential fatal side effects that are possible with this anticonvulsant.

MICROWAVE MEASUREMENT OF REFRACTORY MATERIALS AT HIGH-TEMPERATURE

International Nuclear Information System (INIS)

Kharkovsky, S.; Zoughi, R.; Smith, J.; Davis, B.; Limmer, R.

2009-01-01

Knowledge of the electrical behavior of refractory materials may enable the development and optimization of microwave nondestructive techniques to detect and evaluate changes in their physical properties while the materials are in service. This paper presents the results of a limited and preliminary investigation in which two refractory materials (dense chrome and dense zircon) were subjected to increasing temperature in a furnace and in which a frequency-modulated continuous-wave radar operating in the frequency range of 8-18 GHz radar was used to evaluate their attenuation properties.

Microwave Measurement of Refractory Materials at High-Temperature

Science.gov (United States)

Kharkovsky, S.; Zoughi, R.; Smith, J.; Davis, B.; Limmer, R.

2009-03-01

Knowledge of the electrical behavior of refractory materials may enable the development and optimization of microwave nondestructive techniques to detect and evaluate changes in their physical properties while the materials are in service. This paper presents the results of a limited and preliminary investigation in which two refractory materials (dense chrome and dense zircon) were subjected to increasing temperature in a furnace and in which a frequency-modulated continuous-wave radar operating in the frequency range of 8-18 GHz radar was used to evaluate their attenuation properties.

Ten patients with refractory status epilepticus in an intensive care department

NARCIS (Netherlands)

ter Maaten, JC; van Schijndel, RJM; Heimans, JJ; Schreuder, WO

1998-01-01

Status epilepticus (SE) is a serious disease, associated with a high morbidity and mortality, particularly if refractory to initial therapy. We describe the clinical manifestations and outcome in ten cases with refractory SE admitted to our medical intensive care unit. Three of these selected group

Refractory absence epilepsy associated with GLUT-1 deficiency syndrome.

LENUS (Irish Health Repository)

Byrne, Susan

2011-05-01

GLUT-1 deficiency syndrome (GLUT-1 DS) is a disorder of cerebral glucose transport associated with early infantile epilepsy and microcephaly. We report two boys who presented with refractory absence epilepsy associated with hypoglycorrhachia, both of whom have genetically confirmed GLUT-1 DS. We propose that these children serve to expand the phenotype of GLUT-1 DS and suggest that this condition should be considered as a cause of refractory absence seizures in childhood.

Treatment of Refractory Idiopathic Supraorbital Neuralgia Using Percutaneous Pulsed Radiofrequency.

Science.gov (United States)

Luo, Fang; Lu, Jingjing; Ji, Nan

2018-02-26

No ideal therapeutic method currently exists for refractory idiopathic supraorbital neuralgia patients who do not respond to conservative therapy, including medications and nerve blocks. Pulsed radiofrequency is a neuromodulation technique that does not produce sequelae of nerve damage after treatment. However, the efficacy of percutaneous pulsed radiofrequency for the treatment of refractory idiopathic supraorbital neuralgia is still not clear. The purpose of our study was to evaluate the efficacy and safety of pulsed radiofrequency treatment of the supraorbital nerve for refractory supraorbital neuralgia patients. We prospectively investigated the long-term effects of ultrasound-guided percutaneous pulsed radiofrequency in the treatment of 22 refractory idiopathic supraorbital neuralgia patients. A reduction in the verbal pain numeric rating scale score of more than 50% was used as the standard of effectiveness. The effectiveness rates at different time points within 2 years were calculated. After a single pulsed radiofrequency treatment, the effectiveness rate at 1 and 3 months was 77%, and the rates at 6 months, 1 year, and 2 years were 73%, 64%, and 50%, respectively. Except for a small portion of patients (23%) who experienced mild upper eyelid ecchymosis that gradually disappeared after approximately 2 weeks, no obvious complications were observed. In conclusion, the results of our study demonstrate that for patients with refractory idiopathic supraorbital neuralgia, percutaneous pulsed radiofrequency may be an effective and safe treatment choice. © 2018 World Institute of Pain.

Surgical disconnection of patent paraumbilical vein in refractory hepatic encephalopathy.

Science.gov (United States)

Ishikawa, Yoshinori; Yoshida, Hiroshi; Mamada, Yasuhiro; Taniai, Nobuhiko; Bando, Koichi; Mizuguchi, Yoshiaki; Kakinuma, Daisuke; Kanda, Tomohiro; Akimaru, Koho; Tajiri, Takashi

2008-06-01

Refractory hepatic encephalopathy (HE) frequently develops in patients with cirrhosis and portal-systemic shunt. Recently, patients with refractory HE associated with portal-systemic shunt have been treated with interventional radiology. We describe a promising new treatment for portal-systemic shunt, ligation of the patent paraumbilical vein (PUV) after partial splenic embolization, in patients with refractory HE. Four patients with cirrhosis (3 women and 1 man; mean age, 56 years) and refractory HE due to a patent PUV were studied. Patency of the PUV had recurred in 1 patient after primary occlusion by interventional radiological procedures. The Child-Pugh class was B in 2 patients and C in 2. Before the present treatment, all patients had been hospitalized at least 3 times because of recurrent HE. Partial splenic embolization was performed in all patients to decrease portal venous pressure before surgery. Surgical ligation of the patent PUV was performed under epidural anesthesia. The patent PUV was carefully skeletonized and doubly ligated. Esophageal varices were evaluated with upper gastrointestinal endoscopy before and after surgery. The mean follow-up duration was 15.8 months. After ligation, there were no clinically significant complications. Esophageal varices were unchanged. The serum ammonia level was higher before surgery (162.3 +/- 56.4 mug/dL, mean +/- SD) than after surgery (41.8 +/- 20.2 mug/dL; p=0.0299). No patient had symptoms of HE. Ligation of the patent PUV is an effective treatment for patients with refractory HE.

Bulk Vitrification Performance Enhancement: Refractory Lining Protection Against Molten Salt Penetration

Energy Technology Data Exchange (ETDEWEB)

Hrma, Pavel R.; Bagaasen, Larry M.; Schweiger, Michael J.; Evans, Michael B.; Smith, Benjamin T.; Arrigoni, Benjamin M.; Kim, Dong-Sang; Rodriguez, Carmen P.; Yokuda, Satoru T.; Matyas, Josef; Buchmiller, William C.; Gallegos, Autumn B.; Fluegel, Alexander

2007-08-06

Bulk vitrification (BV) is a process that heats a feed material that consists of glass-forming solids and dried low-activity waste (LAW) in a disposable refractory-lined metal box using electrical power supplied through carbon electrodes. The feed is heated to the point that the LAW decomposes and combines with the solids to generate a vitreous waste form. This study supports the BV design and operations by exploring various methods aimed at reducing the quantities of soluble Tc in the castable refractory block portion of the refractory lining, which limits the effectiveness of the final waste form.

Comparison of Refractory Performance in Black Liquor Gasifiers and a Smelt Test System

International Nuclear Information System (INIS)

Peascoe, RA

2001-01-01

Prior laboratory corrosion studies along with experience at the black liquor gasifier in New Bern, North Carolina, clearly demonstrate that serious material problems exist with the gasifier's refractory lining. Mullite-based and alumina-based refractories used at the New Bern facility suffered significant degradation even though they reportedly performed adequately in smaller scale systems. Oak Ridge National Laboratory's involvement in the failure analysis, and the initial exploration of suitable replacement materials, led to the realization that a simple and reliable, complementary method for refractory screening was needed. The development of a laboratory test system and its suitability for simulating the environment of black liquor gasifiers was undertaken. Identification and characterization of corrosion products were used to evaluate the test system as a rapid screening tool for refractory performance and as a predictor of refractory lifetime. Results from the test systems and pl ants were qualitatively similar

Formation mechanism and control of MgO·Al2O3 inclusions in non-oriented silicon steel

Science.gov (United States)

Sun, Yan-hui; Zeng, Ya-nan; Xu, Rui; Cai, Kai-ke

2014-11-01

On the basis of the practical production of non-oriented silicon steel, the formation of MgO·Al2O3 inclusions was analyzed in the process of "basic oxygen furnace (BOF) → RH → compact strip production (CSP)". The thermodynamic and kinetic conditions of the formation of MgO·Al2O3 inclusions were discussed, and the behavior of slag entrapment in molten steel during RH refining was simulated by computational fluid dynamics (CFD) software. The results showed that the MgO/Al2O3 mass ratio was in the range from 0.005 to 0.017 and that MgO·Al2O3 inclusions were not observed before the RH refining process. In contrast, the MgO/Al2O3 mass ratio was in the range from 0.30 to 0.50, and the percentage of MgO·Al2O3 spinel inclusions reached 58.4% of the total inclusions after the RH refining process. The compositions of the slag were similar to those of the inclusions; furthermore, the critical velocity of slag entrapment was calculated to be 0.45 m·s-1 at an argon flow rate of 698 L·min-1, as simulated using CFD software. When the test steel was in equilibrium with the slag, [Mg] was 0.00024wt%-0.00028wt% and [Al]s was 0.31wt%-0.37wt%; these concentrations were theoretically calculated to fall within the MgO·Al2O3 formation zone, thereby leading to the formation of MgO·Al2O3 inclusions in the steel. Thus, the formation of MgO·Al2O3 inclusions would be inhibited by reducing the quantity of slag entrapment, controlling the roughing slag during casting, and controlling the composition of the slag and the MgO content in the ladle refractory.

Dynamic effective properties of heterogeneous geological formations with spherical inclusions under periodic time variations

Science.gov (United States)

Rabinovich, A.; Dagan, G.; Miloh, T.

2013-04-01

In unsteady groundwater flow (or similar processes of heat/electrical conduction), the heterogeneous medium structure is characterized by two random properties, the conductivity K and the specific storativity S. The average head field ⟨H ⟩and the associated effective properties Kef, Sef are determined for a layer with a periodic head drop between boundaries, such that H is periodic in time, and a medium made up of a matrix with a dilute concentration of spherical inclusions. In the common quasi-steady approximation, Kef is equal to the classical steady solution while Sef = SA, the arithmetic mean. We derive expressions for the frequency dependent Kef, Sef, which are generally complex, i.e., dynamic. The main result is the delineation of the ranges of the parameters: dimensionless frequency (ω) and contrasts of conductivity (κ) and storativity (s) between the matrix and the inclusions, for which dynamic effects are significant.

Oral tranexamic acid lightens refractory melasma.

Science.gov (United States)

Tan, Aaron Wei Min; Sen, Priya; Chua, Sze Hon; Goh, Boon Kee

2017-08-01

Melasma is a common acquired hyperpigmentary disorder, particularly among Asians and Hispanics, but its exact pathomechanism is poorly understood. Tranexamic acid has been found to lighten melasma by interfering with the interaction of melanocytes and keratinocytes by inhibiting the plasminogen/plasmin system. The aim was to evaluate the therapeutic effects of oral tranexamic acid in the treatment of melasma refractory to topical skin-lightening agents. This retrospective study analyses patients with melasma recruited from a tertiary dermatological centre in Singapore between 1 August 2009 and 31 March 2011. The patients chosen had refractory melasma treated with oral tranexamic acid 250 mg twice daily in addition to pre-existing combination topical therapy. Objective assessment using the physician's global assessment and melasma area and severity index (MASI) scores were performed based on a post-hoc analysis of photographic records by three independent physicians. A paired t-test was used to evaluate the changes in the MASI scores pre-therapy and post-treatment. Statistical significance was defined as P tranexamic acid for a mean period of 3.7 ± 0.33 months, in addition to combination topical therapy. Their mean age was 47.2 ± 1.61 years. The mean MASI scores after tranexamic acid treatment (2.7 ± 1.6) were significantly lower (P tranexamic acid can serve as a safe and useful adjunct in the treatment of refractory melasma. © 2016 The Australasian College of Dermatologists.

Clinical features and course of refractory anemia with ring sideroblasts associated with marked thrombocytosis

Science.gov (United States)

Broseus, Julien; Florensa, Lourdes; Zipperer, Esther; Schnittger, Susanne; Malcovati, Luca; Richebourg, Steven; Lippert, Eric; Cermak, Jaroslav; Evans, Jyoti; Mounier, Morgane; Raya, José Maria; Bailly, François; Gattermann, Norbert; Haferlach, Torsten; Garand, Richard; Allou, Kaoutar; Besses, Carlos; Germing, Ulrich; Haferlach, Claudia; Travaglino, Erica; Luno, Elisa; Pinan, Maria Angeles; Arenillas, Leonor; Rozman, Maria; Perez Sirvent, Maria Luz; Favre, Bernardine; Guy, Julien; Alonso, Esther; Ahwij, Nuhri; Jerez, Andrés; Hermouet, Sylvie; Maynadié, Marc; Cazzola, Mario; Girodon, François

2012-01-01

Background Refractory anemia with ring sideroblasts associated with marked thrombocytosis was proposed as a provisional entity in the 2001 World Health Organization classification of myeloid neoplasms and also in the 2008 version, but its existence as a single entity is contested. We wish to define the clinical features of this rare myelodysplastic/myeloproliferative neoplasm and to compare its clinical outcome with that of refractory anemia with ring sideroblasts and essential thrombocythemia. Design and Methods We conducted a collaborative retrospective study across Europe. Our database included 200 patients diagnosed with refractory anemia with ring sideroblasts and marked thrombocytosis. For each of these patients, each patient diagnosed with refractory anemia with ring sideroblasts was matched for age and sex. At the same time, a cohort of 454 patients with essential thrombocythemia was used to compare outcomes of the two diseases. Results In patients with refractory anemia with ring sideroblasts and marked thrombocytosis, depending on the Janus Kinase 2 V617F mutational status (positive or negative) or platelet threshold (over or below 600×109/L), no difference in survival was noted. However, these patients had shorter overall survival and leukemia-free survival with a lower risk of thrombotic complications than did patients with essential thrombocythemia (P<0.001) but better survival (P<0.001) and a higher risk of thrombosis (P=0.039) than patients with refractory anemia with ring sideroblasts. Conclusions The clinical course of refractory anemia with ring sideroblasts and marked thrombocytosis is better than that of refractory anemia with ring sideroblasts and worse than that of essential thrombocythemia. The higher risk of thrombotic events in this disorder suggests that anti-platelet therapy might be considered in this subset of patients. From a clinical point of view, it appears to be important to consider refractory anemia with ring sideroblasts and

Study on the RF inductively coupled plasma spheroidization of refractory W and W-Ta alloy powders

Science.gov (United States)

Chenfan, YU; Xin, ZHOU; Dianzheng, WANG; Neuyen VAN, LINH; Wei, LIU

2018-01-01

Spherical powders with good flowability and high stacking density are mandatory for powder bed additive manufacturing. Nevertheless, the preparation of spherical refractory tungsten and tungsten alloy powders is a formidable task. In this paper, spherical refractory metal powders processed by high-energy stir ball milling and RF inductively coupled plasma were investigated. By utilizing the technical route, pure spherical tungsten powders were prepared successfully, the flowability increased from 10.7 s/50 g to 5.5 s/50 g and apparent density increased from 6.916 g cm-3 to 11.041 g cm-3. Alloying element tantalum can reduce the tendency to micro-crack during tungsten laser melting and rapid solidification process. Spherical W-6Ta (%wt) powders were prepared in this way, homogeneous dispersion of tantalum in a tungsten matrix occurred but a small amount of flake-like shape particles appeared after high-energy stir ball milling. The flake-like shape particles can hardly be spheroidized in subsequent RF inductively coupled plasma process, might result from the unique suspended state of flaky particles under complex electric and magnetic fields as well as plasma-particle heat exchange was different under various turbulence models. As a result, the flake-like shape particles cannot pass through the high-temperature area of thermal plasma torch and cannot be spheroidized properly.

Nanostructured refractory thin films for solar applications

Science.gov (United States)

Ollier, E.; Dunoyer, N.; Dellea, O.; Szambolics, H.

2014-08-01

Selective solar absorbers are key elements of all solar thermal systems. Solar thermal panels and Concentrated Solar Power (CSP) systems aim respectively at producing heat and electricity. In both cases, a surface receives the solar radiation and is designed to have the highest optical absorption (lowest optical reflectivity) of the solar radiation in the visible wavelength range where the solar intensity is the highest. It also has a low emissivity in the infrared (IR) range in order to avoid radiative thermal losses. Current solutions in the state of the art usually consist in deposited interferential thin films or in cermets [1]. Structured surfaces have been proposed and have been simulated because they are supposed to be more efficient when the solar radiation is not normal to the receiving surface and because they could potentially be fabricated with refractory materials able to sustain high operating temperatures. This work presents a new method to fabricate micro/nanostructured surfaces on molybdenum (refractory metal with a melting temperature of 2623°C). This method now allows obtaining a refractory selective surface with an excellent optical selectivity and a very high absorption in the visible range. This high absorption performance was obtained by achieving a double structuration at micro and nano scales thanks to an innovative process flow.

Low-Chrome/Chrome Free Refractories for Slagging Gasifiers

International Nuclear Information System (INIS)

Bennett, J.P.; Kwong, K.-S.; Powell, C.P.; Thomas, H.; Petty, A.V. Jr.

2007-01-01

Gasifiers are containment vessels used to react carbon-containing materials with oxygen and water, producing syngas (CO and H2) that is used in chemical and power production. It is also a potential source of H2 in a future hydrogen economy. Air cooled slagging gasifiers are one type of gasifier, operating at temperatures from 1275-1575 C and at pressures of 400 psi or higher. They typically use coal or petroleum coke as the carbon source, materials which contain ash impurities that liquefy at the gasification temperatures, producing liquid slag in quantities of 100 or more tons/day, depending on the carbon fed rate and the percent ash present in the feedstock. The molten slag is corrosive to refractory linings, causing chemical dissolution and spalling. The refractory lining is composed of chrome oxide, alumina, and zirconia; and is replaced every 3-24 months. Gasifier users would like greater on-line availability and reliability of gasifier liners, something that has impacted gasifier acceptance by industry. Research is underway at NETL to improve refractory service life and to develop a no-chrome or low-chrome oxide alternative refractory liner. Over 250 samples of no- or low-chrome oxide compositions have been evaluated for slag interactions by cup testing; with potential candidates for further studies including those with ZrO2, Al2O3, and MgO materials. The development of improved liner materials is necessary if technologies such as IGCC and DOE's Near Zero Emissions Advanced Fossil Fuel Power Plant are to be successful and move forward in the marketplace

Super-Refractory Status Epilepticus: Report of a Case and Review of the Literature.

Science.gov (United States)

Lapenta, Leonardo; Frisullo, Giovanni; Vollono, Catello; Brunetti, Valerio; Giannantoni, Nadia Mariagrazia; Sandroni, Claudio; Di Lella, Giuseppe; Della Marca, Giacomo

2015-10-01

Super-refractory status epilepticus (SE; ie, SE continuing or recurring despite 24 hours of general anesthesia) is a severe condition with high percentage of mortality and morbidity. Usually, this condition occurs because of serious brain damage; nevertheless, some patients develop super-refractory SE without identifiable etiology. Although not uncommonly encountered in neurointensive care, scientific data on this condition are still lacking in terms of treatment and prognosis. Herein, we report a case of super-refractory SE with recovery after 50 days, despite electroencephalographic (EEG) and magnetic resonance imaging (MRI) signs traditionally related to poor prognosis. A review of the literature on super-refractory SE is also presented. © EEG and Clinical Neuroscience Society (ECNS) 2014.

Omalizumab therapy for refractory allergic fungal rhinosinusitis patients with moderate or severe asthma.

Science.gov (United States)

Gan, Eng Cern; Habib, Al-Rahim R; Rajwani, Alykhan; Javer, Amin R

2015-01-01

1. To assess the efficacy of omalizumab therapy in improving sinonasal outcomes in refractory allergic fungal rhinosinusitis (AFRS) patients with moderate or severe asthma. 2. To determine if omalizumab therapy reduces the usage of corticosteroids or antifungal therapy in AFRS patients The clinical charts of patients with AFRS with moderate or severe asthma who received at least three subcutaneous injections of omalizumab therapy between 1st January 2012 and 1st May 2014 were retrospectively reviewed. These patients had undergone bilateral functional endoscopic sinus surgery (FESS) and failed adjunct medical treatments (oral or topical corticosteroids and/or antifungal therapy) prior to omalizumab therapy. Seven patients met the inclusion criteria and were included in this study. The mean age of the patients was 48.14. The average number of subcutaneous omalizumab injections was 7.57 (range 6-11) with a mean dosage of 287mg (range 225-375mg). The mean pre-omalizumab treatment Sino-Nasal Outcome Test-22 (SNOT-22) score was 52.14 while the mean post-omalizumab treatment SNOT-22 score was 35.86 (31% improvement). The mean pre-omalizumab therapy Phillpott-Javer endoscopic score (over the last one year before omalizumab therapy) was 36 while the mean post-omalizumab therapy endoscopic score (from the last clinic visit) was 14 (61% improvement). Omalizumab therapy reduced the dependence of AFRS patients on corticosteroid and antifungal treatments. Omalizumab therapy can be considered as a potential adjunct for the treatment for patients with refractory AFRS with moderate or severe asthma. However, larger prospective studies to confirm the findings of this study will be required. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

Tioguanine in the treatment of refractory coeliac disease--a single centre experience.

Science.gov (United States)

Tack, G J; van Asseldonk, D P; van Wanrooij, R L J; van Bodegraven, A A; Mulder, C J

2012-08-01

Refractory coeliac disease type I is a complicated form of coeliac disease characterised by primary or secondary resistance to a gluten-free diet with persisting or reoccurring intestinal villous atrophy and symptoms of malabsorption. Besides corticosteroids, azathioprine has been advocated for the treatment of refractory coeliac disease type I. However, tioguanine (TG) might be better tolerated and more efficacious owing to a simpler metabolism towards bioactivation. To evaluate tolerability and effectiveness of the nonconventional thiopurine derivative TG in refractory coeliac disease type I. Refractory coeliac disease type I patients treated with TG between June 2001 and November 2010 with a follow-up period of at least 1 year were included. Adverse events, laboratory values, 6-thioguanine nucleotide concentrations and rates of both clinical and histological response were evaluated at baseline and during follow-up. Twelve adult refractory coeliac disease type I patients were included. The median TG treatment duration was 14 months. Ten patients tolerated TG treatment on the long term, whereas two patients withdrew treatment due to adverse events. No nodular regenerative hyperplasia of the liver was observed. During follow-up clinical and histological response was observed in 83% and 78%, respectively. Corticosteroid dependency decreased by 50%. Tioguanine appears to be a convenient drug for the treatment of refractory coeliac disease type I based on higher histological and similar clinical response rates as compared with historical conventional therapies. © 2012 Blackwell Publishing Ltd.

Refractory, Abrasive and Other Industrial Mineral Operations

Data.gov (United States)

Department of Homeland Security — This map layer includes refractory, abrasive, and other industrial minerals operations in the United States. The data represent commodities covered by the Minerals...

Evaluation of nutritional status in children with refractory epilepsy

Directory of Open Access Journals (Sweden)

Testolin G

2006-04-01

Full Text Available Abstract Background children affected by refractory epilepsy could be at risk of malnutrition because of feeding difficulties (anorexia, chewing, swallowing difficulties or vomiting and chronic use of anticonvulsants, which may affect food intake and energy metabolism. Moreover, their energy requirement may be changed as their disabilities would impede normal daily activities. The aim of the present study was to evaluate nutritional status, energy metabolism and food intake in children with refractory epilepsy. Methods 17 children with refractory epilepsy (13 boys and 4 girls; mean age 9 ± 3,2 years; Body Mass Index 15,7 ± 3,6 underwent an anthropometric assessment, body composition evaluation by dual-energy X-ray absorptiometry, detailed dietetic survey and measurement of resting energy expenditure by indirect calorimetry. Weight-for-age, height-for-age (stunting and weight-for-height (wasting were estimated compared to those of a reference population of the same age. Results 40% of children were malnourished and 24% were wasted. The nutritional status was worse in the more disabled children. Dietary intake resulted unbalanced (18%, 39%, 43% of total daily energy intake derived respectively from protein, lipid and carbohydrate. Adequacy index [nutrient daily intake/recommended allowance (RDA × 100] was Conclusion many children with refractory epilepsy would benefit from individual nutritional assessment and management as part of their overall care.

Regorafenib Versus Trifluridine/Tipiracil for Refractory Metastatic Colorectal Cancer: A Retrospective Comparison.

Science.gov (United States)

Masuishi, Toshiki; Taniguchi, Hiroya; Hamauchi, Satoshi; Komori, Azusa; Kito, Yosuke; Narita, Yukiya; Tsushima, Takahiro; Ishihara, Makoto; Todaka, Akiko; Tanaka, Tsutomu; Yokota, Tomoya; Kadowaki, Shigenori; Machida, Nozomu; Ura, Takashi; Fukutomi, Akira; Ando, Masashi; Onozawa, Yusuke; Tajika, Masahiro; Yasui, Hirofumi; Muro, Kei; Mori, Keita; Yamazaki, Kentaro

2017-06-01

Regorafenib and trifluridine/tipiracil (TAS-102) both prolong survival for patients with refractory metastatic colorectal cancer. However, it is unclear which drug should be administered first. We retrospectively evaluated the data from patients who had received regorafenib or TAS-102 at 2 institutions from May 2013 to March 2015. The inclusion criteria were disease refractory or intolerant to fluoropyrimidines, oxaliplatin, irinotecan, anti-vascular endothelial growth factor antibodies, and anti-epidermal growth factor receptor (EGFR) antibodies (if KRAS exon 2 wild-type), and no previous treatment with regorafenib or TAS-102. A total of 146 and 54 patients received regorafenib and TAS-102, respectively. The baseline characteristics were similar between the 2 groups, except for a history of irinotecan and anti-EGFR therapy and high alkaline phosphatase levels. The median progression-free survival and overall survival were 2.1 months and 6.7 months, respectively, with regorafenib and 2.1 months and 6.5 months, respectively, with TAS-102 (progression-free survival hazard ratio 1.20, P = .27; overall survival hazard ratio, 1.01, P = .97). The analysis of overall survival for patients after the approval of TAS-102 in Japan was similar to the overall survival for the entire population. The frequency of hand-foot syndrome and increased aspartate aminotransferase, alanine aminotransferase, and bilirubin levels was higher and the frequency of neutropenia, leukopenia, anemia, nausea, and febrile neutropenia was lower with regorafenib than with TAS-102. No remarkable differences were found in the efficacy and safety of TAS-102 between patients with and without previous regorafenib and vice versa. Regorafenib and TAS-102 had similar efficacy but resulted in different toxicities, which could guide the agent choice. Copyright © 2016 Elsevier Inc. All rights reserved.

Improvement of castable refractories for RH snorkel; RH shinshitsukanyo futeikeizai no kaizen

Energy Technology Data Exchange (ETDEWEB)

Nishi, K.; Obana, T.; Fijii, T.; Shimizu, I. [Harima Ceramics Corp., Hyogo (Japan)

1999-11-01

Relating to corrosion of RH submerged nozzle, resistance against iron oxide of monolithic refractories was examined. Corrosion and seepage of refractories were measured by rotating corrosion, refractories include alumina-spinel castable, which is applied to RH under tank, and alumina-magnesia castable, which is generally used for RH, submerged nozzle. Alumina-spinel castable is superior in resistance against iron oxide than alumina-magnesia castable, and the resistance decreased with increase of stainless fiber addition to castable. Alumina-spinel castable without stainless fiber was suitable for bottom end of the dipping pipe. (NEDO)

Effectiveness of intravenous levetiracetam as an adjunctive treatment in pediatric refractory status epilepticus.

Science.gov (United States)

Kim, Jon Soo; Lee, Jeong Ho; Ryu, Hye Won; Lim, Byung Chan; Hwang, Hee; Chae, Jong-Hee; Choi, Jieun; Kim, Ki Joong; Hwang, Yong Seung; Kim, Hunmin

2014-08-01

Intravenous levetiracetam (LEV) has been shown to be effective and safe in treating adults with refractory status epilepticus (SE). We sought to investigate the efficacy and safety of intravenous LEV for pediatric patients with refractory SE. We performed a retrospective medical-record review of pediatric patients who were treated with intravenous LEV for refractory SE. Clinical information regarding age, sex, seizure type, and underlying neurological status was collected. We evaluated other anticonvulsants that were used prior to administration of intravenous LEV and assessed loading dose, response to treatment, and any adverse events from intravenous LEV administration. Fourteen patients (8 boys and 6 girls) received intravenous LEV for the treatment of refractory SE. The mean age of the patients was 4.4 ± 5.5 years (range, 4 days to 14.6 years). Ten of the patients were neurologically healthy prior to the refractory SE, and the other 4 had been previously diagnosed with epilepsy. The mean loading dose of intravenous LEV was 26 ± 4.6 mg/kg (range, 20-30 mg/kg). Seizure termination occurred in 6 (43%) of the 14 patients. In particular, 4 (57%) of the 7 patients younger than 2 years showed seizure termination. No immediate adverse events occurred during or after infusions. The current study demonstrated that the adjunctive use of intravenous LEV was effective and well tolerated in pediatric patients with refractory SE, even in patients younger than 2 years. Intravenous LEV should be considered as an effective and safe treatment option for refractory SE in pediatric patients.

Analysis of Historic Copper Patinas. Influence of Inclusions on Patina Uniformity

Directory of Open Access Journals (Sweden)

Tingru Chang

2017-03-01

Full Text Available The morphology and elemental composition of cross sections of eight historic copper materials have been explored. The materials were taken from copper roofs installed in different middle and northern European environments from the 16th to the 19th century. All copper substrates contain inclusions of varying size, number and composition, reflecting different copper ores and production methods. The largest inclusions have a size of up to 40 μm, with most inclusions in the size ranging between 2 and 10 μm. The most common element in the inclusions is O, followed by Pb, Sb and As. Minor elements include Ni, Sn and Fe. All historic patinas exhibit quite fragmentized bilayer structures, with a thin inner layer of cuprite (Cu2O and a thicker outer one consisting mainly of brochantite (Cu4SO4(OH6. The extent of patina fragmentation seems to depend on the size of the inclusions, rather than on their number and elemental composition. The larger inclusions are electrochemically nobler than the surrounding copper matrix. This creates micro-galvanic effects resulting both in a profound influence on the homogeneity and morphology of historic copper patinas and in a significantly increased ratio of the thicknesses of the brochantite and cuprite layers. The results suggest that copper patinas formed during different centuries exhibit variations in uniformity and corrosion protection ability.

Neuroimaging in refractory epilepsy. Current practice and evolving trends

Energy Technology Data Exchange (ETDEWEB)

Ramli, N. [Department of Biomedical Imaging, University Malaya Research Imaging Centre (Malaysia); Rahmat, K., E-mail: katt_xr2000@yahoo.com [Department of Biomedical Imaging, University Malaya Research Imaging Centre (Malaysia); Lim, K.S.; Tan, C.T. [Neurology Unit, Department of Medicine, University Malaya, Kuala Lumpur (Malaysia)

2015-09-15

Highlights: • Neuroimaging is imperative in diagnostic work up and therapeutic assessment of refractory epilepsy. • Identification of epileptogenic zone on EEG, MRI and functional imaging improves the success of surgery. • High performance MRI greatly enhanced metabolic information and elucidate brain functions. • Optimisation of epilepsy protocols in structural and functional MRI are presented in this article. - Abstract: Identification of the epileptogenic zone is of paramount importance in refractory epilepsy as the success of surgical treatment depends on complete resection of the epileptogenic zone. Imaging plays an important role in the locating and defining anatomic epileptogenic abnormalities in patients with medically refractory epilepsy. The aim of this article is to present an overview of the current MRI sequences used in epilepsy imaging with special emphasis of lesion seen in our practices. Optimisation of epilepsy imaging protocols are addressed and current trends in functional MRI sequences including MR spectroscopy, diffusion tensor imaging and fusion MR with PET and SPECT are discussed.

Neuroimaging in refractory epilepsy. Current practice and evolving trends

International Nuclear Information System (INIS)

Ramli, N.; Rahmat, K.; Lim, K.S.; Tan, C.T.

2015-01-01

Highlights: • Neuroimaging is imperative in diagnostic work up and therapeutic assessment of refractory epilepsy. • Identification of epileptogenic zone on EEG, MRI and functional imaging improves the success of surgery. • High performance MRI greatly enhanced metabolic information and elucidate brain functions. • Optimisation of epilepsy protocols in structural and functional MRI are presented in this article. - Abstract: Identification of the epileptogenic zone is of paramount importance in refractory epilepsy as the success of surgical treatment depends on complete resection of the epileptogenic zone. Imaging plays an important role in the locating and defining anatomic epileptogenic abnormalities in patients with medically refractory epilepsy. The aim of this article is to present an overview of the current MRI sequences used in epilepsy imaging with special emphasis of lesion seen in our practices. Optimisation of epilepsy imaging protocols are addressed and current trends in functional MRI sequences including MR spectroscopy, diffusion tensor imaging and fusion MR with PET and SPECT are discussed

The effect of various sintering temperature on used refractory towards its physical properties

Science.gov (United States)

Sudibyo; Wulandari, Y. R.; Amin, M.; Azhar

2018-01-01

The used magnesia refractory from the kiln of cement industry was successfully recycled to new refractory using Kaolin as an adhesive. In this work, the temperatures of sintering were varied from 1000°C to 1500°C. The result shows that the increment temperature effects in sintering process will enhance refractory physical properties such as bulk density, cold crushing strength or pressure strength and thermal conductivity. Meanwhile, the porosity was decreased as the increase of the sintering temperature.

Rapid pacing results in changes in atrial but not in ventricular refractoriness

NARCIS (Netherlands)

Schoonderwoerd, BA; Van Gelder, IC; Tieleman, RG; Bel, KJ; Crijns, HJGM

It is well known that atrial tachycardia causes atrial electrical remodeling, characterized by shortening of atrial effective refractory periods (AERPs) and loss of physiological adaptation of AERP to rate. However, the nature and time course of changes in ventricular effective refractory periods

Rhenium-osmium systematics of calcium-aluminium-rich inclusions in carbonaceous chondrites

Science.gov (United States)

Becker, H.; Morgan, J.W.; Walker, R.J.; MacPherson, G.J.; Grossman, J.N.

2001-01-01

The Re-Os isotopic systematics of calcium-aluminium-rich inclusions (CAIs) in chondrites were investigated in order to shed light on the behavior of the Re-Os system in bulk chondrites, and to constrain the timing of chemical fractionation in primitive chondrites. CAIs with relatively unfractionated rare earth element (REE) patterns (groups I, III, V, VI) define a narrow range of 187Re/188Os (0.3764-0.4443) and 187Os/188Os (0.12599-0.12717), and high but variable Re and Os abundances (3209-41,820 ppb Os). In contrast, CAIs that show depletions in highly refractory elements and strongly fractionated REE patterns (group II) also show a much larger range in 187Re/188Os (0.409-0.535) and 187Os/188Os (0.12695-0.13770), and greater than an order of magnitude lower Re and Os abundances than other groups (e.g., 75.7-680.2 ppb Os). Sixteen bulk CAIs and CAI splits plot within analytical uncertainty of a 4558 Ga reference isochron, as is expected for materials of this antiquity. Eight samples, however, plot off the isochron. Several possible reasons for these deviations are discussed. Data for multiple splits of one CAI indicate that the nonisochronous behavior for at least this CAI is the result of Re-Os reequilibration at approximately 1.6 Ga. Thus, the most likely explanation for the deviations of most of the nonisochronous CAIs is late-stage open-system behavior of Re and Os in the asteroidal environment. The 187Os/188Os-Os systematics of CAIs are consistent with previous models that indicate group II CAIs are mixtures of components that lost the bulk of their highly refractory elements in a previous condensation event and a minor second component that provided refractory elements at chondritic relative proportions. The high Re/Os of group II CAIs relative to other CAIs and chondrite bulk rocks may have been caused by variable mobilization of Re and Os during medium- to low-temperature parent body alteration ??4.5 Ga ago. This model is favored over nebular models, which

Transient refractory material dissolution by a volumetrically-heated melt

Energy Technology Data Exchange (ETDEWEB)

Seiler, Jean Marie, E-mail: jean-marie.seiler@cea.fr [CEA, DEN, DTN, 17 Rue des Martyrs, 38054 Grenoble Cedex 9 (France); Ratel, Gilles [CEA, DEN, DTN, 17 Rue des Martyrs, 38054 Grenoble Cedex 9 (France); Combeau, Hervé [Institut Jean Lamour, UMR 7198, Lorraine University, Ecole des Mines de Nancy, Parc de Saurupt, 54042 Nancy Cedex (France); Gaus-Liu, Xiaoyang; Kretzschmar, Frank; Miassoedov, Alexei [Karlsruhe Institut of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

2014-12-15

Highlights: • We describe a test investigating ceramic dissolution by a molten non-eutectic melt. • The evolution of the interface temperature between melt and refractory is measured. • A theoretical model describing dissolution kinetics is proposed. • When dissolution stops, interface temperature is the liquidus temperature of the melt. - Abstract: The present work addresses the question of corium–ceramic interaction in a core catcher during a core-melt accident in a nuclear power plant. It provides an original insight into transient aspects concerning dissolution of refractory material by a volumetrically heated pool. An experiment with simulant material (LIVECERAM) is presented. Test results clearly show that dissolution of solid refractory material can occur in a non-eutectic melt at a temperature which is lower than the melting temperature of the refractory material. During the dissolution transient, the interface temperature rises above the liquidus temperature, corresponding to the instantaneous average composition of the melt pool. With constant power dissipation in the melt and external cooling of the core-catcher, a final steady-state situation is reached. Dissolution stops when the heat flux (delivered by the melt to the refractory) can be removed by conduction through the residual thickness of the ceramic, with T{sub interface} = T{sub liquidus} (calculated for the average composition of the final liquid pool). The final steady state corresponds to a uniform pool composition and uniform interface temperature distribution. Convection in the pool is governed by natural thermal convection and the heat flux distribution is therefore similar to what would be obtained for a single component pool. An interpretation of the experiment with two model-based approaches (0D and 1D) is presented. The mass transfer kinetics between the interface and the bulk is controlled by a diffusion sublayer within the boundary layer. During the dissolution transient

Literature Review of Saccharomyces boulardii in the Treatment of Refractory Recurrent Clostridium difficile Infection

Directory of Open Access Journals (Sweden)

Rachel Warila

2017-09-01

Full Text Available Objective: To evaluate the efficacy of S. boulardii for the treatment of recurrent C. difficile infections.Methods: Eligible articles included S. boulardii in patients with recurrent C. difficile infection. The primary endpoint examined was clinical resolution of infection with no further recurrences during follow-up.Results: Six studies met inclusion criteria. A case report showed resolution of recurrences in one patient, and an experimental trial showed a trend towards decreased recurrences in patients receiving S. boulardii (85% no further recurrences. Two randomized controlled trials found a significant decrease in recurrences for S. boulardii versus placebo (34.6% vs 64.7%, P=0.04; 16.7% vs 50%, P=0.05. One meta-analysis determined significant efficacy for S. boulardii in reducing relapses (RR 0.59, 95% CI 0.35-0.98, while another concluded there was insufficient evidence to recommend probiotics for C. difficile infection.Conclusions: S. boulardii may be considered for patients with recurrent C. difficile infection, refractory to antibiotic regimens alone.

A randomized controlled trial of the ketogenic diet in refractory childhood epilepsy

NARCIS (Netherlands)

Lambrechts, D.A.J.E.; de Kinderen, R.J.A.; Vles, J.S.H.; de Louw, A.J.A.; Aldenkamp, A.P.; Majoie, H.J.M.

2017-01-01

Objective: To evaluate the efficacy and tolerability of the ketogenic diet (KD) during the first 4 months of a randomized controlled trial (RCT) in refractory epilepsy patients aged 1–18 years. Methods: Children and adolescents with refractory epilepsy, not eligible for epilepsy surgery, were

Improved cooler design of electric arc furnace refractory in mining industry using thermal analysis modeling and simulation

International Nuclear Information System (INIS)

Istadi, I.; Bindar, Y.

2014-01-01

Production of steel and nickel using the electric arc furnace should be focused on the intensification of energy. Improvement of energy efficiency of the most consuming facilities was achieved by improving the use of alternative energy minimization such as reducing the heat lost of hot gases, minimizing the heat radiated through refractory linings of metallurgical furnaces, and cooling the highly thermally stressed components. The refractory of electric arc furnace should be modified to achieve the best cooling system of the furnace. In this physical modeling and simulation works, four modification scenarios of wall refractory designs were simulated, i.e. refractory with basic design, refractory with deep plate coolers, refractory with extra plate coolers, and refractory with wall falling film coolers. Finally, the use of deep plate cooler and the existing waffle cooler system was considered to be the best design of efficient electric arc furnace operationally. - Highlights: • Electric arc furnace design should be focused on the intensification of energy. • Refractory of electric arc furnace were modified to achieve the best cooling system. • Four modification scenarios of the wall refractory designs were simulated. • Use of deep plate cooler and existing waffle cooler system is the best cooling

PARTITIONING TUNGSTEN BETWEEN MATRIX PRECURSORS AND CHONDRULE PRECURSORS THROUGH RELATIVE SETTLING

Energy Technology Data Exchange (ETDEWEB)

Hubbard, Alexander, E-mail: ahubbard@amnh.org [American Museum of Natural History, New York, NY (United States)

2016-08-01

Recent studies of chondrites have found a tungsten isotopic anomaly between chondrules and matrix. Given the refractory nature of tungsten, this implies that W was carried into the solar nebula by at least two distinct families of pre-solar grains. The observed chondrule/matrix split requires that the distinct families were kept separate during the dust coagulation process, and that the two families of grain interacted with the chondrule formation mechanism differently. We take the co-existence of different families of solids in the same general orbital region at the chondrule-precursor size as given, and explore the requirements for them to have interacted with the chondrule formation process at significantly different rates. We show that this sorting of families of solids into chondrule- and matrix-destined dust had to have been at least as powerful a sorting mechanism as the relative settling of aerodynamically distinct grains at least two scale heights above the midplane. The requirement that the chondrule formation mechanism was correlated in some fashion with a dust-grain sorting mechanism argues strongly for spatially localized chondrule formation mechanisms such as turbulent dissipation in non-thermally ionized disk surface layers, and argues against volume-filling mechanisms such as planetesimal bow shocks.

PARTITIONING TUNGSTEN BETWEEN MATRIX PRECURSORS AND CHONDRULE PRECURSORS THROUGH RELATIVE SETTLING

International Nuclear Information System (INIS)

Hubbard, Alexander

2016-01-01

Recent studies of chondrites have found a tungsten isotopic anomaly between chondrules and matrix. Given the refractory nature of tungsten, this implies that W was carried into the solar nebula by at least two distinct families of pre-solar grains. The observed chondrule/matrix split requires that the distinct families were kept separate during the dust coagulation process, and that the two families of grain interacted with the chondrule formation mechanism differently. We take the co-existence of different families of solids in the same general orbital region at the chondrule-precursor size as given, and explore the requirements for them to have interacted with the chondrule formation process at significantly different rates. We show that this sorting of families of solids into chondrule- and matrix-destined dust had to have been at least as powerful a sorting mechanism as the relative settling of aerodynamically distinct grains at least two scale heights above the midplane. The requirement that the chondrule formation mechanism was correlated in some fashion with a dust-grain sorting mechanism argues strongly for spatially localized chondrule formation mechanisms such as turbulent dissipation in non-thermally ionized disk surface layers, and argues against volume-filling mechanisms such as planetesimal bow shocks.

Ixabepilone: a new chemotherapeutic option for refractory metastatic breast cancer

Directory of Open Access Journals (Sweden)

Shannon Puhalla

2008-09-01

Full Text Available Shannon Puhalla, Adam BrufskyUPMC Magee-Womens Cancer Program, University of Pittsburgh, Pittsburgh, Pennsylvania, USAAbstract: Taxane therapy is commonly used in the treatment of metastatic breast cancer. However, most patients will eventually become refractory to these agents. Ixabepilone is a newly approved chemotherapeutic agent for the treatment of metastatic breast cancer. Although it targets microtubules similarly to docetaxel and paclitaxel, ixabepilone has activity in patients that are refractory to taxanes. This review summarizes the pharmacology of ixapebilone and clinical trials with the drug both as a single agent and in combination. Data were obtained using searches of PubMed and abstracts of the annual meetings of the American Society of Clinical Oncology and the San Antonio Breast Cancer Symposium from 1995 to 2008. Ixapebilone is a semi-synthetic analog of epothilone B that acts to induce apoptosis of cancer cells via the stabilization of microtubules. Phase I clinical trials have employed various dosing schedules ranging from daily to weekly to 3-weekly. Dose-limiting toxicites included neuropathy and neutropenia. Responses were seen in a variety of tumor types. Phase II studies verified activity in taxane-refractory metastatic breast cancer. The FDA has approved ixabepilone for use as monotherapy and in combination with capecitabine for the treatment of metastatic breast cancer. Ixabepilone is an efficacious option for patients with refractory metastatic breast cancer. The safety profile is similar to that of taxanes, with neuropathy and neutropenia being dose-limiting. Studies are ongoing with the use of both iv and oral formulations and in combination with other chemotherapeutic and biologic agents.Keywords: ixabepilone, epothilone, metastatic breast cancer, taxane-refractory

Clinical outcomes of intravenous immunoglobulin therapy in refractory uveitis.

Science.gov (United States)

Garcia-Geremias, M; Carreño, E; Epps, S J; Lee, R W J; Dick, A D

2015-04-01

Intravenous immunoglobulin (IVIg) therapy has multiple mechanisms of immunomodulatory action. We wished therefore to assess its efficacy in a spectrum of patients with refractory uveitis. Retrospective review of clinical charts was conducted to document response to IVIg treatment in consecutive patients with treatment-refractory uveitis. Main outcome measures were control of intraocular inflammation, visual acuity, progression of the disease, and complications. Four (two male) patients, with a mean age at the beginning of the treatment of 47 years (range: 39-64), were included in the study. Indication for treatment was patients with active non-infectious uveitis refractory to steroids and immunomodulatory therapy. All patients received a course of 0.5 g/kg per day of IVIg for three consecutive days, repeating this course at a mean of 11 week (range: 2-39 weeks) intervals when indicated clinically. The median duration of the IVIg therapy was 7 months (range: 3-14 months). In three patients treatment resulted in stabilisation and prevention of progression of the disease, and additionally in two patients it facilitated a decrease in prednisolone dose. Treatment failed to induce long-term remission in one patient with recurrence of macular oedema. IVIg was well tolerated with neither immediate nor longer-term adverse events observed. In three out of four cases IVIg was an effective adjunctive therapy and well tolerated for the management of treatment-refractory uveitis.

Advances in refractories for the metallurgical industries III: proceedings of the international symposium

Energy Technology Data Exchange (ETDEWEB)

Allaire, C.; Rigaud, M. [eds.] [Ecole Polytchnique, Montreal, PQ (Canada)

1999-07-01

In the three years since the last symposium key innovations have been made in the penetration of monoliths in all sectors of the metallurgical industries. The symposium was presented within the 38th Annual Conference of Metallurgists of the Canadian Institute of Mining, Metallurgy and Petroleum. Broad international coverage was maintained with papers originating from 12 different countries including: Australia, Canada, China, France, Germany, India, Iran, Japan, Korea, Mexico, New Zealand, Norway, and the United States. The 27 papers presented are divided into seven sessions to reflect the interests of the participants. The sessions included mold fluxes I and II, aluminum refractories, alumina castables, andalusite castables, continuous casting of refractories, aluminum refractories II and copper-nickel refineries. One paper on refractories for exhaust gas scrubbers is abstracted separately.

Evaluation of refractory materials for a nuclear waste incinerator

International Nuclear Information System (INIS)

Grotzky, V.K.; Kneale, P.A.; Teter, A.R.

1980-01-01

An experiment to find a suitable refractory lining for a nuclear waste incinerator has been completed. Eleven brick and six castable products were analyzed by optical and scanning microscopy. All the materials were fashioned into cup shapes and subjected to temperatures ranging from 800 to 1200 0 C for as long as six weeks. Some of the cups were charged weekly with pellets made from ash materials that would contact an incinerator liner. Refractory products containing a high percentage of aluminum oxide had the greatest resistance to cracking and slag buildup. 35 figures

Refractory status epilepticus and glutamic acid decarboxylase antibodies in adults: presentation, treatment and outcomes.

Science.gov (United States)

Khawaja, Ayaz M; Vines, Brannon L; Miller, David W; Szaflarski, Jerzy P; Amara, Amy W

2016-03-01

Glutamic acid decarboxylase antibodies (GAD-Abs) have been implicated in refractory epilepsy. The association with refractory status epilepticus in adults has been rarely described. We discuss our experience in managing three adult patients who presented with refractory status epilepticus associated with GAD-Abs. Case series with retrospective chart and literature review. Three patients without pre-existing epilepsy who presented to our institution with generalized seizures between 2013 and 2014 were identified. Seizures proved refractory to first and second-line therapies and persisted beyond 24 hours. Patient 1 was a 22-year-old female who had elevated serum GAD-Ab titres at 0.49 mmol/l (normal: status epilepticus. Causation cannot be established since GAD-Abs may be elevated secondary to concurrent autoimmune diseases or formed de novo in response to GAD antigen exposure by neuronal injury. Based on this report and available literature, there may be a role for immuno- and chemotherapy in the management of refractory status epilepticus associated with GAD-Abs.

Production of NbC reinforced aluminum matrix composites by mechanical alloying

International Nuclear Information System (INIS)

Silva, Marina Judice; Cardoso, Katia Regina; Travessa, Dilermando Nagle

2014-01-01

Aluminum and their alloys are key materials for the automotive and aerospace industries. The dispersion of hard ceramic particles in the Al soft matrix produces lightweight composites with interesting properties, as environmental resistance, high specific strength and stiffness, high thermal and electrical conductivity, and good wear resistance, encouraging their technological use. Powder metallurgy techniques like mechanical alloying (MA) are very attractive to design metal matrix composites, as they are able to achieve a homogeneous distribution of well dispersed particles inside the metal matrix. In this work, pure aluminum has been reinforced with particles of Niobium carbide (NbC), an extremely hard and stable refractory ceramic. NbC is frequently used as a grain growth inhibitor in micro-alloyed steel due to their low solubility in austenite. In the present work, NbC is expected to act as a reinforcing phase by its fine dispersion into the aluminum matrix, produced by MA. Composite powders produced after different milling times (up to 50h), with 10 and 20% (volume) of NbC were characterized by diffraction laser particle size analysis, scanning electron microscopy (SEM) and by X-ray diffraction (DRX), in order to establish a relationship between the milling time and the characteristics of the powder produced, as size and morphology, crystallite size and reinforcement distribution. This characterization is important in defining the MA process for production of composites for further consolidation by hot extrusion process. (author)

Production of NbC reinforced aluminum matrix composites by mechanical alloying

Energy Technology Data Exchange (ETDEWEB)

Silva, Marina Judice; Cardoso, Katia Regina; Travessa, Dilermando Nagle, E-mail: dilermando.travessa@unifesp.br [Universidade Federal de Sao Paulo (UNIFESP), Sao Jose dos Campos, SP (Brazil). Instituto de Ciencia e Tecnologia

2014-07-01

Aluminum and their alloys are key materials for the automotive and aerospace industries. The dispersion of hard ceramic particles in the Al soft matrix produces lightweight composites with interesting properties, as environmental resistance, high specific strength and stiffness, high thermal and electrical conductivity, and good wear resistance, encouraging their technological use. Powder metallurgy techniques like mechanical alloying (MA) are very attractive to design metal matrix composites, as they are able to achieve a homogeneous distribution of well dispersed particles inside the metal matrix. In this work, pure aluminum has been reinforced with particles of Niobium carbide (NbC), an extremely hard and stable refractory ceramic. NbC is frequently used as a grain growth inhibitor in micro-alloyed steel due to their low solubility in austenite. In the present work, NbC is expected to act as a reinforcing phase by its fine dispersion into the aluminum matrix, produced by MA. Composite powders produced after different milling times (up to 50h), with 10 and 20% (volume) of NbC were characterized by diffraction laser particle size analysis, scanning electron microscopy (SEM) and by X-ray diffraction (DRX), in order to establish a relationship between the milling time and the characteristics of the powder produced, as size and morphology, crystallite size and reinforcement distribution. This characterization is important in defining the MA process for production of composites for further consolidation by hot extrusion process. (author)

Evaluation of olivine refractories for TES

Science.gov (United States)

Gay, B. M.; Cochrane, R. L.; Palmour, H., III; Paisley, M. J.

1982-02-01

The principal objectives of this program are to (1) experimentally determine the degree of improvement in thermal and mechanical performance that can be obtained with an olivine thermal storage brick made of domestic materials using advanced processing techniques compared with state-of-the-art as represented by commercial European bricks, (2) conduct an assessment of existing German ceramic process technology and determine its adaptability to domestic raw materials and manufacturing practices, and (3) investigate, on a limited basis, method for further improvement of domestic-olivine brick. To date, accomplishments include (1) installation of improved, computer-based instrumentation, (2) the use of this system to determine performance characteristics of a set of heat storage refractories under cyclic use conditions, (3) acquisition of the services of a knowledgeable European consultant, (4) continued lab-scale process/property optimization studies, and (5) comparative testing of olivine-based and magnesite-based heat storage refractories in the calorimetric test facility at Purdue University.

An unusual case of refractory wheeze

Science.gov (United States)

Ramesh, Venkat; Acharya, Vishak; Pai, Narasimha; Krishnan, Ananda

2015-01-01

A 37-year-old man presented with a history of episodic wheeze and breathlessness of 3 years’ duration refractory to treatment. Physical examination revealed diffuse expiratory polyphonic rhonchi while the remainder of the examination including the cardiac examination was reported as normal. Pulmonary function testing revealed mild obstruction with bronchodilator reversibility. The patient was discharged on a 6-month course of antitubercular treatment (ATT) as bronchial brush cytology (obtained via bronchoscopy) was positive for acid-fast bacilli. The patient presented after completing 6 months of ATT with persistent symptoms, a loud S1 and a mid-diastolic murmur at the apex. High-resolution CT of the chest showed bilateral dependent ground glass opacities. An echocardiogram revealed a left atrial myxoma, and normal RV size and pressures. The patient underwent successful surgical removal of the same, and made a complete recovery. Refractory wheeze is a very unusual presentation of a left atrial myxoma. PMID:25733086

Effect of non-metallic inclusions on hydrogen-induced cracking of API5L X100 steel

Energy Technology Data Exchange (ETDEWEB)

Jin, T.Y.; Liu, Z.Y.; Cheng, Y.F. [Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Alberta (Canada)

2010-08-15

In this work, the type, composition and distribution of inclusions contained in an API5L X100 steel were characterized by scanning electron microscopy and energy-dispersive x-ray analysis. A hydrogen-charging at various current densities was used to introduce hydrogen into the steel, and the correlation between HIC and the inclusions was established. The microstructure of the steel consists of a leather-like bainitic ferrite matrix, with martensite/austenite as the second phase particles. At least four types of inclusions are contained in API5L X100 steel, elongated MnS inclusions and spherical Al-, Si- and Ca-Al-O-S-enriched inclusions. In particular, the majority of inclusions in the steel are Al-enriched. Upon hydrogen-charging, hydrogen blisters and HIC could be caused in the steel in the absence of external stress. The cracks are primarily associated with the Al- and Si-enriched inclusions, rather than the elongated MnS inclusion. The critical amount of hydrogen resulting in HIC of the tested API5L X100 steel is determined to be 3.24 ppm under condition in this work. (author)

Self-Consistency Method to Evaluate a Linear Expansion Thermal Coefficient of Composite with Dispersed Inclusions

Directory of Open Access Journals (Sweden)

V. S. Zarubin

2015-01-01

Full Text Available The rational use of composites as structural materials, while perceiving the thermal and mechanical loads, to a large extent determined by their thermoelastic properties. From the presented review of works devoted to the analysis of thermoelastic characteristics of composites, it follows that the problem of estimating these characteristics is important. Among the thermoelastic properties of composites occupies an important place its temperature coefficient of linear expansion.Along with fiber composites are widely used in the technique of dispersion hardening composites, in which the role of inclusions carry particles of high-strength and high-modulus materials, including nanostructured elements. Typically, the dispersed particles have similar dimensions in all directions, which allows the shape of the particles in the first approximation the ball.In an article for the composite with isotropic spherical inclusions of a plurality of different materials by the self-produced design formulas relating the temperature coefficient of linear expansion with volume concentration of inclusions and their thermoelastic characteristics, as well as the thermoelastic properties of the matrix of the composite. Feature of the method is the self-accountability thermomechanical interaction of a single inclusion or matrix particles with a homogeneous isotropic medium having the desired temperature coefficient of linear expansion. Averaging over the volume of the composite arising from such interaction perturbation strain and stress in the inclusions and the matrix particles and makes it possible to obtain such calculation formulas.For the validation of the results of calculations of the temperature coefficient of linear expansion of the composite of this type used two-sided estimates that are based on the dual variational formulation of linear thermoelasticity problem in an inhomogeneous solid containing two alternative functional (such as Lagrange and Castigliano

Preparation and characterization of clay bonded high strength silica refractory by utilizing agriculture waste

International Nuclear Information System (INIS)

Bhardwaj, A.; Hossain, S.K.S.; Majh, M.R.

2017-01-01

Clay bonded silica refractory was prepared by utilizing agriculture waste called rice husk ash (RHA) and refractory grog. Various samples were prepared with different compositions based upon partial replacement of quartz by RHA. Rectangular samples were prepared by following semi dry process prior to pressing in a uniaxial hydraulic press and sintering at a temperature of 1200°C in air atmosphere. Various physical, mechanical and thermal characterizations were done like X-ray diffraction (XRD), scanning electron microscope (SEM), apparent porosity (AP), bulk density (BD), cold crushing strength (CCS), refractoriness and thermal conductivity measurement. The sample utilizing 30% of RHA was considered most optimum composition which produced cold crushing strength of 38MPa and thermal conductivity of 2.08W/mK at 800°C with a considerable good refractoriness. Enhancement in the mechanical as well as thermal properties may be considered as attributed to the amorphous silica which has reacted more easily and efficiently with other material surrounding giving rise to the densification and produced stable crystalline phase to the refractory material. These promising characteristics suggests that the RHA may lead to be used as a potential material for the preparation of clay bonded high strength silica refractories. [es

Enhancement of the life of refractories through the operational experience of plasma torch melter

Energy Technology Data Exchange (ETDEWEB)

Moon, Young Pyo [Technology Institute, Korea Radioactive waste Agency (KORAD), Daejeon (Korea, Republic of); Choi, Jaang Young [Chungnam National University, Daejeon (Korea, Republic of)

2016-06-15

The properties of wastes for melting need to be considered to minimize the maintenance of refractory and to discharge the molten slags smoothly from a plasma torch melter. When the nonflammable wastes from nuclear facilities such as concrete debris, glass, sand, etc., are melted, they become acid slags with low basicity since the chemical composition has much more acid oxides than basic oxides. A molten slag does not have good characteristics of discharge and is mainly responsible for the refractory erosion due to its low liquidity. In case of a stationary plasma torch melter with a slant tapping port on the wall, a fixed amount of molten slags remains inside of tapping hole as well as the melter inside after tapping out. Nonmetallic slags keep the temperature higher than melting point of metal because metallic slags located on the bottom of melter by specific gravity difference are simultaneously melted when dual mode plasma torch operates in transferred mode. In order to minimize the refractory erosion, the compatible refractories are selected considering the temperature inside the melter and the melting behavior of slags whether to contact or noncontact with molten slags. An acidic refractory shall not be installed in adjacent to a basic refractory for the resistibility against corrosion.

Refractory heartburn: comparison of intercellular space diameter in documented GERD vs. functional heartburn.

Science.gov (United States)

Vela, Marcelo F; Craft, Brandon M; Sharma, Neeraj; Freeman, Janice; Hazen-Martin, Debra

2011-05-01

Refractory heartburn despite acid suppression may be explained by ongoing gastroesophageal reflux disease (GERD) or functional heartburn (FH), i.e., symptoms without evidence of GERD. Impedance-pH monitoring (impedance-pH) detects acid and nonacid reflux and is useful for evaluating acid-suppressed, refractory patients. Intercellular space diameter (ISD) of esophageal epithelium measured by transmission electron microscopy (TEM) is a marker of epithelial damage present in both erosive and nonerosive reflux disease. ISD has not been used to study refractory heartburn or FH. Our aim was to compare ISD in healthy controls and refractory heartburn patients with GERD and FH. In refractory heartburn patients (heartburn more than twice/week for at least 2 months despite proton pump inhibitor (PPI) b.i.d.), erosive esophagitis and/or abnormal impedance-pH (increased acid exposure or positive symptom index) defined GERD; normal esophagogastroduodenoscopy (EGD)/impedance-pH defined FH. Asymptomatic, healthy controls had normal EGD and pH-metry. Mean ISD in each subject, determined by blinded TEM of esophageal biopsies, was the average of 100 measurements (10 measurements in each of 10 micrographs). In all, 11 healthy controls, 11 FH, and 15 GERD patients were studied. Mean ISD was significantly higher in GERD compared with controls (0.87 vs. 0.32 μm, P=0.003) and FH (0.87 vs. 0.42 μm, P=0.012). Mean ISD was similar in FH and controls (0.42 vs. 0.32 μm, P=0.1). The proportion of patients with abnormal ISD was significantly higher for GERD compared with FH (60 vs. 9%, P=0.014). ISD is increased in refractory heartburn patients with GERD but not those with FH. Our findings suggest that measurement of ISD by TEM might be a useful tool to distinguish GERD from FH in patients with refractory heartburn.

Colectomy for refractory constipation

DEFF Research Database (Denmark)

Raahave, Dennis; Loud, Franck Bjørn; Christensen, Elsebeth

2010-01-01

OBJECTIVE: This study evaluated the type of colectomy, postoperative complications, functional results, and satisfaction in patients with constipation refractory to conservative therapy. Further, colonic transit time (CTT), faecal load (coprostasis), and colon length (redundancies) were compared...... had at hemicolectomy, 11 patients a subtotal colectomy and 3 patients an ileostomy. Two patients had an anastomotic leak and one died. In 11 patients, further surgery was necessary, because of recurrent constipation. Abdominal pain disappeared and defecation patterns improved significantly to 1-4 per...

Refractory alloy component fabrication

International Nuclear Information System (INIS)

Young, W.R.

1984-01-01

Purpose of this report is to describe joining procedures, primarily welding techniques, which were developed to construct reliable refractory alloy components and systems for advanced space power systems. Two systems, the Nb-1Zr Brayton Cycle Heat Receiver and the T-111 Alloy Potassium Boiler Development Program, are used to illustrate typical systems and components. Particular emphasis is given to specific problems which were eliminated during the development efforts. Finally, some thoughts on application of more recent joining technology are presented. 78 figures

Method for hot pressing irregularly shaped refractory articles

Science.gov (United States)

Steinkamp, William E.; Ballard, Ambrose H.

1982-01-01

The present invention is directed to a method for hot pressing irregularly haped refractory articles with these articles of varying thickness being provided with high uniform density and dimensional accuracy. Two partially pressed compacts of the refractory material are placed in a die cavity between displaceable die punches having compact-contacting surfaces of the desired article configuration. A floating, rotatable block is disposed between the compacts. The displacement of the die punches towards one another causes the block to rotate about an axis normal to the direction of movement of the die punches to uniformly distribute the pressure loading upon the compacts for maintaining substantially equal volume displacement of the powder material during the hot pressing operation.

Ketogenic Diet in Super-Refractory Status Epilepticus

OpenAIRE

Smith, Garnett; Press, Craig A.

2017-01-01

Researchers from the Children’s National Health System in Washington, D.C. studied the feasibility, rate of complications, and effect on seizures of initiating the Ketogenic Diet (KD) in pediatric patients with Super-Refractory Status Epilepticus (SRSE).

Clinical and etiological profile of refractory rickets from western India.

Science.gov (United States)

Joshi, Rajesh R; Patil, Shailesh; Rao, Sudha

2013-07-01

To present clinical and etiological profile of refractory rickets from Mumbai. Case records of 36 patients presenting over 2½ y with refractory rickets were evaluated with respect to clinical presentation, biochemical, radiological features and where needed, ophthalmological examination, ultrasonography and special tests on blood and urine. Twenty three (63 %) patients had renal tubular acidosis (RTA)-distal RTA in 20 and proximal RTA in 3 patients; 5 (14 %) had vitamin D dependent rickets (VDDR I in 2 and VDDR II in 3 patients), 4 (11 %) had chronic renal failure (CRF) and 2 each (6 %) had hypophosphatemic rickets and chronic liver disease as cause of refractory rickets. A significant proportion of patients with RTA and VDDR showed skeletal changes of rickets in the first 2 y of life, while those with hypophosphatemic rickets presented later. Patients with hypophosphatemic rickets had predominant involvement of lower limbs, normal blood calcium and PTH levels and phosphorus leak in urine. All patients with RTA presented with failure to thrive, polyuria and marked rickets; blood alkaline phosphatase levels being normal in almost 50 % patients. Three (75 %) patients with rickets due to CRF had GFR rickets inspite of taking high dose of vitamin D orally. Refractory rickets is a disorder of multiple etiologies; a good history and clinical examination supplemented with appropriate investigations helps to determine its cause.

USE OF STRUCTURAL MRI IN PATIENTS WITH MEDICALLY REFRACTORY SEIZURES

Directory of Open Access Journals (Sweden)

Ara G. Kaprelyan

2012-12-01

Full Text Available Introduction: Refractory epilepsy is common in patients with structural brain lesions including acquired disorders and genetic abnormalities. Recently, MRI is a precise diagnostic tool for recognition of different structural causes underlying medically intractable seizures.Objective: To evaluate the usefulness of MRI for detection of brain lesions associated with refractory epilepsy.Material and methods: 49 patients (20M and 29F; aged 48.6±24.7 years with refractory epilepsy were included in the study. They presented with partial (46.0%, secondary (31.0% or primary (23.0% generalized tonic-clonic seizures. Clinical diagnosis was based on the revised criteria of ILAE. Structural neuroimaging (MRI, EEG recording, and neurological examination were performed.Results: MRI detected different structural brain abnormalities totally in 36 (73.5% patients, including cerebral tumors (21p, cerebrovascular accidents (5p, hyppocampal sclerosis (3p, developmental malformations (2p, postencephalitic lesions (2p, arachnoid cysts (2p, and tuberous sclerosis (1p. Neuroimaging revealed normal findings in 13 (27.5% cases. EEG recordings showed focal epileptic activity in 38 (77.6% patients, including 33 cases with and 5 without structural brain abnormalities.Conclusion: This study revealed that structural brain lesions are commonly associated with refractory epilepsy. We suggested that MRI is a useful diagnostic method for assessment of patients with uncontrolled seizures or altered epileptic pattern.

Penetration and Effectiveness of Micronized Copper in Refractory Wood Species.

Science.gov (United States)

Civardi, Chiara; Van den Bulcke, Jan; Schubert, Mark; Michel, Elisabeth; Butron, Maria Isabel; Boone, Matthieu N; Dierick, Manuel; Van Acker, Joris; Wick, Peter; Schwarze, Francis W M R

2016-01-01

The North American wood decking market mostly relies on easily treatable Southern yellow pine (SYP), which is being impregnated with micronized copper (MC) wood preservatives since 2006. These formulations are composed of copper (Cu) carbonate particles (CuCO3·Cu(OH)2), with sizes ranging from 1 nm to 250 μm, according to manufacturers. MC-treated SYP wood is protected against decay by solubilized Cu2+ ions and unreacted CuCO3·Cu(OH)2 particles that successively release Cu2+ ions (reservoir effect). The wood species used for the European wood decking market differ from the North American SYP. One of the most common species is Norway spruce wood, which is poorly treatable i.e. refractory due to the anatomical properties, like pore size and structure, and chemical composition, like pit membrane components or presence of wood extractives. Therefore, MC formulations may not suitable for refractory wood species common in the European market, despite their good performance in SYP. We evaluated the penetration effectiveness of MC azole (MCA) in easily treatable Scots pine and in refractory Norway spruce wood. We assessed the effectiveness against the Cu-tolerant wood-destroying fungus Rhodonia placenta. Our findings show that MCA cannot easily penetrate refractory wood species and could not confirm the presence of a reservoir effect.

Wettability between TiN,TiC Containing Carbon Composite Refractory and Molten Slag or Hot Metal

Institute of Scientific and Technical Information of China (English)

SHIYue－xun; LIYingand; 等

1994-01-01

In order to develop a new-type TiC-TiN containing carbon composite refractory so as to improve the service life of blast furnace hearth,the wettability between the carbon refractory and molten slag or metal has been mea-sured.It was indicated that the carbon refractory is wet-ted by slag(θ≤90°） when(TiC+TiN)>33.52%,The effects of TiN or TiC on wetting behavior are basi-cally identical.When the amount of TiC in the carbon com-posite refractory is greater than 60% it will be wetted by hot metal;therefore,the carbon composite refractory will be wetted by slag but not permeated by hot metal when the amount of TiC is restricted.

Refractory Coated/Lined Low Density Structures, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — This project addresses the development of refractory coated or lined low density structures applicable for advanced future propulsion system technologies. The...

Refractory Hypertension: Determination of Prevalence, Risk Factors and Comorbidities in a Large, Population-Based Cohort

Science.gov (United States)

Calhoun, David A.; Booth, John N.; Oparil, Suzanne; Irvin, Marguerite R.; Shimbo, Daichi; Lackland, Daniel T.; Howard, George; Safford, Monika M.; Muntner, Paul

2014-01-01

Refractory hypertension is an extreme phenotype of antihypertensive treatment failure. Participants in the REasons for Geographic And Racial Differences in Stroke (REGARDS) Study, a large (n=30,239), population-based cohort were evaluated to determine the prevalence of refractory hypertension and associated cardiovascular risk factors and comorbidities. Refractory hypertension was defined as uncontrolled blood pressure (systolic/diastolic ≥ 140/90 mm Hg) on ≥ 5 antihypertensive drug classes. Participants with resistant hypertension (systolic/diastolic ≥140/90 mm Hg on ≥ 3 orhypertensive participants served as comparator groups. Of 14,809 REGARDS participants receiving antihypertensive treatment, 78 (0.5%) had refractory hypertension. The prevalence of refractory hypertension was 3.6% among participants with resistant hypertension(n=2,144) and 41.7% among participants on 5 or more antihypertensive drug classes. Among all hypertensive participants, African American race, male gender, living in the stroke belt or buckle, higher body mass index, lower heart rate, reduced estimated glomerular filtration rate, albuminuria, diabetes and history of stroke and coronary heart disease were associated with refractory hypertension. Compared to resistant hypertension, prevalence ratios for refractory hypertension were increased for African Americans (3.00, 95% CI 1.68 – 5.37) and those with albuminuria (2.22, 95% CI 1.40 – 3.52) and diabetes (2.09, 95% CI 1.32 – 3.31). The median 10-year Framingham risk for coronary heart disease and stroke was higher among participants with refractory hypertension compared to either comparator group. These data indicate that while resistant hypertension is relatively common among treated hypertensive patients, true antihypertensive treatment failure is rare. PMID:24324035

Super-refractory status epilepticus in West China.

Science.gov (United States)

Tian, L; Li, Y; Xue, X; Wu, M; Liu, F; Hao, X; Zhou, D

2015-07-01

This study aims to determine the general frequency, mortality, and risk factors of super-refractory status epilepticus (SRSE) versus non-refractory status epilepticus (NRSE) and refractory status epilepticus (RSE). This work is a retrospective study. Clinical data of patients who were diagnosed with status epilepticus (SE) in the neurological ward and neuro-intensive care unit of West China Hospital from January 2009 to December 2012 were collected and analyzed. A total of 98 patients were included in the study. The percentages of NRSE, RSE, and SRSE were 67.3%, 20.4%, and 12.2%, respectively. Convulsive SE was the main seizure type among the three groups. The most common cause of NRSE was related to epilepsy (EP). However, 67.7% of SRSE cases were caused by acute encephalitis. Moreover, 47% of SE and 40% of RSE cases had a history of EP, whereas only 8.3% of SRSE cases had such history (P  0.05). The general mortality of SE was 7.1%, whereas that of SRSE was 50%. During follow-up, most SRSE patients who survived have developed symptomatic EP. This study was the first to use the statistical percentage of SRSE. Approximately 12.2% of SE cases will result in SRSE, which is a challenging medical situation for doctors. Patients with first episodes and acute encephalitis were also prone to develop SRSE. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A coated rigid elliptical inclusion loaded by a couple in the presence of uniform interfacial and hoop stresses

Science.gov (United States)

Wang, Xu; Schiavone, Peter

2018-06-01

We consider a confocally coated rigid elliptical inclusion, loaded by a couple and introduced into a remote uniform stress field. We show that uniform interfacial and hoop stresses along the inclusion-coating interface can be achieved when the two remote normal stresses and the remote shear stress each satisfy certain conditions. Our analysis indicates that: (i) the uniform interfacial tangential stress depends only on the area of the inclusion and the moment of the couple; (ii) the rigid-body rotation of the rigid inclusion depends only on the area of the inclusion, the coating thickness, the shear moduli of the composite and the moment of the couple; (iii) for given remote normal stresses and material parameters, the coating thickness and the aspect ratio of the inclusion are required to satisfy a particular relationship; (iv) for prescribed remote shear stress, moment and given material parameters, the coating thickness, the size and aspect ratio of the inclusion are also related. Finally, a harmonic rigid inclusion emerges as a special case if the coating and the matrix have identical elastic properties.

Refractory experience in circulating fluidized bed combustors, Task 7

Energy Technology Data Exchange (ETDEWEB)

Vincent, R.Q.

1989-11-01

This report describes the results of an investigation into the status of the design and selection of refractory materials for coal-fueled circulating fluidized-bed combustors. The survey concentrated on operating units in the United States manufactured by six different boiler vendors: Babcock and Wilcox, Combustion Engineering, Foster Wheeler, Keeler Dorr-Oliver, Pyropower, and Riley Stoker. Information was obtained from the boiler vendors, refractory suppliers and installers, and the owners/operators of over forty units. This work is in support of DOE's Clean Coal Technology program, which includes circulating fluidized-bed technology as one of the selected concepts being evaluated.

Refractory metal component technology for in-core sensor design

International Nuclear Information System (INIS)

Cannon, C.P.

1986-02-01

Within recent years, an increasing concern over reactor safety has prompted tests that characterize reactor core environments during transient conditions. Such tests include the Loss-of-Fluid-Tests (Idaho National Engineering Lab (INEL)), Severe Fuel Damage Tests (INEL), Core Debris Rubble Tests (Sandia National Laboratories (SNL)), and similar tests performed by foreign nations. The in-core sensors for these tests require refractory metal components to be compatible with electrical insulator materials as well as materials comprising highly corrosive service mediums. This paper presents the refractory metal technology utilized to provide basic sensor designs in the above mentioned reactor tests

Mechanical activation of ceramic powders and its influence on the quality of the refractory linings

International Nuclear Information System (INIS)

Ceganac, Z.; Acimovic, Z.; Andric, Lj.; Petrov, M.; Mihajlovic, S.

2003-01-01

In the paper we present results of the investigation of the influence of mechanical activation of ceramic powders-talc and alumina, on the quality of refractory linings for casting applications. It is shown that additional fine grinding of ceramic powders increases the quality of the refractory lining. Grinding and activation of the particles with various granulations contributes to the creation of the homogenous continuous layer of refractory lining on the sand moulds and cores, as well as on the evaporating polystyrene patterns for applications in the Lost foam casting process. Refractory linings obtained within the activation of particles procedure have better adherence to moulds, cores and evaporating patterns. (Original)

High Throughput Drug Sensitivity Assay and Genomics- Guided Treatment of Patients With Relapsed or Refractory Acute Leukemia

Science.gov (United States)

2018-02-28

Acute Leukemia of Ambiguous Lineage; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Refractory Acute Myeloid Leukemia; Refractory Adult Acute Lymphoblastic Leukemia; Refractory Childhood Acute Lymphoblastic Leukemia

Thermodynamics of inclusion formation and its influence on the corrosion behavior of Cu bearing duplex stainless steels

International Nuclear Information System (INIS)

Jeon, Soon-Hyeok; Kim, Soon-Tae; Lee, In-Sung; Park, Yong-Soo; Park, Joo-Hyun; Kim, Kwang-Tae; Kim, Ji-Soo

2011-01-01

To elucidate the thermodynamics of inclusion formation and its influence on the corrosion behavior of Cu bearing duplex stainless steels, potentiodynamic and potentiostatic polarization tests, a SEM-EDS analysis of inclusions, and thermodynamic calculations of the formation of inclusions were carried out. While the resistance to general corrosion of the noble copper contained alloy-1.5Cu in a deaerated 2 M H 2 SO 4 was higher than that of the alloy-BASE, the resistance to pitting corrosion of copper contained alloy-1.5Cu in a deaerated 0.5 N HCl + 1 N NaCl and 30 mass% NaCl was lower than that of the alloy-BASE due to an increase of interface areas between inclusions and matrix acting as preferential pit initiation sites. The thermodynamic calculation for the formation of Cr-containing oxide inclusions was in good agreement with the experimental results. (author)

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr.; Alireza Rezaie

2003-12-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the materials problems encountered during the operation of low-pressure high-temperature (LFHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

Refractory for Black Liquor Gasifiers

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Alireza Rezaie

2003-12-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the materials problems encountered during the operation of low-pressure high-temperature (LFHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

Refractory for Black Liquor Gasifiers

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Alireza Rezaie; Xiaoting Liang; Musa Karakus; Jun Wei

2005-12-01

The University of Missouri-Rolla identified materials that permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project was to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study attempted to define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials were selected or developed that reacted with the gasifier environment to form protective surfaces in

Refractory for Black Liquor Gasifiers

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Musa Karakus; Xiaoting Liang

2005-10-01

The University of Missouri-Rolla identified materials that permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project was to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study attempted to define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials were selected/developed that either react with the gasifier environment to form protective surfaces in

Refractory for Black Liquor Gasifiers

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick; Musa Karakus; Alireza Rezaie

2004-03-30

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Musa Karakus; Xiaoting Liang; Alireza Rezaie

2004-07-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Musa Karakus; Xiaoting Liang; Alireza Rezaie

2004-10-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Musa Karakus; Xiaoting Liang; Jun Wei

2005-01-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Musa Karakus; Xiaoting Liang; Jun Wei

2005-04-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Musa Karakus; Xiaoting Liang

2005-07-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr.; Alireza Rezaie

2004-04-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the materials problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

Testing Consent Order on Refractory Ceramic Fibers

Science.gov (United States)

This notice announces that EPA has signed signed an enforceable testing consent order under the Toxic Substances Control Act (TSCA), 15 U.S.C. section 2601 at seq., with three of the primary producers of refractory ceramic fibers (RCF).

Matrix elements of Yale potential and level properties of light nuclei

Energy Technology Data Exchange (ETDEWEB)

Kumar, N; Prakash, O [Delhi Univ. (India). Dept. of Physics and Astrophysics

1976-07-01

Shell model calculations using bare and renormalized matrix elements of the Yale potential are reported for the normal-parity states of A = 6-9 nuclei. Renormalization of the two-body matrix elements using second-order perturbation theory is not found to improve the agreements with the experimental data. Inclusion of the energy shifts of ground state rotational bands in /sup 8/Be and /sup 9/Be are, however, found to improve the agreements with the excitation energies of nuclear levels. The need for carrying out more calculations of these nuclei with realistic forces is pointed out.

Improving outcomes of refractory celiac disease – current and emerging treatment strategies

Directory of Open Access Journals (Sweden)

Woodward J

2016-08-01

Full Text Available Jeremy Woodward Department of Gastroenterology and Clinical Nutrition, Addenbrooke’s Hospital, Cambridge, UK Abstract: Intestinal inflammation and symptoms of celiac disease (CD usually respond well to gluten withdrawal, but rare cases are refractory to diet. Two types of refractory CD are discriminated on the basis of the presence or absence of an atypical population of mucosal lymphocytes that may progress to enteropathy-associated T-cell lymphoma. Challenges remain in the secure diagnosis of both types of refractory disease, and evidence on which to base treatment recommendations is flawed by the small numbers of reported patients and the use of different diagnostic strategies. Recent advances in our understanding of the mechanisms of the condition in conjunction with the development of immunomodulatory agents for managing other inflammatory diseases are helping to shape future approaches to targeted therapy. Progression will depend on collaboration and recruitment to trials. In the meantime, there is evidence to suggest that earlier diagnosis and better follow-up and management of CD may prevent the development of refractoriness. Keywords: celiac disease, gluten, small intestine, lymphoma, lymphocytes

Influence of Annealing on Microstructure and Mechanical Properties of Refractory CoCrMoNbTi0.4 High-Entropy Alloy

Science.gov (United States)

Zhang, Mina; Zhou, Xianglin; Zhu, Wuzhi; Li, Jinghao

2018-04-01

A novel refractory CoCrMoNbTi0.4 high-entropy alloy (HEA) was prepared via vacuum arc melting. After annealing treatment at different temperatures, the microstructure evolution, phase stability, and mechanical properties of the alloy were investigated. The alloy was composed of two primary body-centered cubic structures (BCC1 and BCC2) and a small amount of (Co, Cr)2Nb-type Laves phase under different annealing conditions. The microhardness and compressive strength of the heat-treated alloy was significantly enhanced by the solid-solution strengthening of the BCC phase matrix and newborn Laves phase. Especially, the alloy annealed at 1473 K (1200 °C) achieved the maximum hardness and compressive strength values of 959 ± 2 HV0.5 and 1790 MPa, respectively, owing to the enhanced volume fraction of the dispersed Laves phase. In particular, the HEAs exhibited promising high-temperature mechanical performance, when heated to an elevated temperature of 1473 K (1200 °C), with a compressive fracture strength higher than 580 MPa without fracture at a strain of more than 20 pct. This study suggests that the present refractory HEAs have immense potential for engineering applications as a new class of high-temperature structural materials.

NOVEL REFRACTORY MATERIALS FOR HIGH ALKALI, HIGH TEMPERATURE ENVIRONMENTS

Energy Technology Data Exchange (ETDEWEB)

Hemrick, James Gordon [ORNL; Smith, Jeffrey D [ORNL; O' Hara, Kelley [University of Missouri, Rolla; Rodrigues-Schroer, Angela [Minteq International, Inc.; Colavito, [Minteq International, Inc.

2012-08-01

A project was led by Oak Ridge National Laboratory (ORNL) in collaboration with a research team comprised of the academic institution Missouri University of Science and Technology (MS&T), and the industrial company MINTEQ International, Inc. (MINTEQ), along with representatives from the aluminum, chemical, glass, and forest products industries. The project was to address the need for new innovative refractory compositions by developing a family of novel MgO-Al 2O3, MgAl2O4, or other similar spinel structured or alumina-based unshaped refractory compositions (castables, gunnables, shotcretes, etc.) utilizing new aggregate materials, bond systems, protective coatings, and phase formation techniques (in-situ phase formation, altered conversion temperatures, accelerated reactions, etc). This family of refractory compositions would then be tailored for use in high-temperature, high-alkaline industrial environments like those found in the aluminum, chemical, forest products, glass, and steel industries. Both practical refractory development experience and computer modeling techniques were used to aid in the design of this new family of materials. The newly developed materials were expected to offer alternative material choices for high-temperature, high-alkali environments that were capable of operating at higher temperatures (goal of increasing operating temperature by 100-200oC depending on process) or for longer periods of time (goal of twice the life span of current materials or next process determined service increment). This would lead to less process down time, greater energy efficiency for associated manufacturing processes (more heat kept in process), and materials that could be installed/repaired in a more efficient manner. The overall project goal was a 5% improvement in energy efficiency (brought about through a 20% improvement in thermal efficiency) resulting in a savings of 3.7 TBtu/yr (7.2 billion ft3 natural gas) by the year 2030. Additionally, new

Service life prediction for refractory materials

Czech Academy of Sciences Publication Activity Database

Boccaccini, D. N.; Cannio, M.; Volkov-Husović, T. D.; Kamseu, E.; Romagnoli, M.; Veronesi, P.; Leonelli, C.; Dlouhý, Ivo; Boccaccini, A. R.

2008-01-01

Roč. 43, č. 12 (2008), s. 4079-4090 ISSN 0022-2461 R&D Projects: GA ČR(CZ) GA106/05/0495 Institutional research plan: CEZ:AV0Z20410507 Keywords : refractory materials * ultrasonic velocity * fracture toughness Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 1.181, year: 2008

Refractory chronic cluster headache

DEFF Research Database (Denmark)

Mitsikostas, Dimos D; Edvinsson, Lars; Jensen, Rigmor H

2014-01-01

Chronic cluster headache (CCH) often resists to prophylactic pharmaceutical treatments resulting in patients' life damage. In this rare but pragmatic situation escalation to invasive management is needed but framing criteria are lacking. We aimed to reach a consensus for refractory CCH definition...... for clinical and research use. The preparation of the final consensus followed three stages. Internal between authors, a larger between all European Headache Federation members and finally an international one among all investigators that have published clinical studies on cluster headache the last five years...

Stereological observations of platelet-reinforced mullite- and zirconia-matrix composites

International Nuclear Information System (INIS)

Cherian, I.K.; Kriven, W.M.; Lehigh, M.D.; Nettleship, I.

1996-01-01

Recently, the effect of solid inclusions on the sintering of ceramic powders has been explained in terms of a back-stress that opposes densification. Several analyses have been proposed to describe this problem. However, little quantitative information exists concerning the effect of reinforcement on microstructural evolution. This study compares the microstructural development of zirconia and mullite matrices in the presence of alumina platelets. The effect of platelet loading on density is similar for both composites. Quantitative stereological examinations reveal that the average grain size and pore size are finer for the zirconia-matrix composite. The platelet loading does not have any noticeable effect on the average grain size of the matrix in either composite. However, the average pore size increases as the volume fraction of platelets increases for both materials. Contiguity measurements have detected some aggregation of platelets in the zirconia-matrix composite

Study on the efficiency of ceramic coating for avoiding oxidation in carbon refractories

International Nuclear Information System (INIS)

Santos, I.M.G.; Cruz Junior, F.; Paskocimas, C.A.; Leite, E.R.; Longo, Elson; Varela, J.A.

1997-01-01

A ceramic coating made of sodium phosphossilicate and clay was developed to the protection of refractories against carbon oxidation during the pre-heating of siderurgical equipment. This search has the objective of comparing the refractory behaviour with and without coating, according to temperature, time and atmosphere. The results show that the coating is more efficient at higher temperatures. An important point is that the efficiency is smaller after long thermal is that the efficiency is smaller after long thermal treatments and at very aggressive conditions. In spite of this the oxidation is still smaller than in refractory without coating. (author)

Iron Refractory Iron Deficiency Anaemia: A Rare Cause of Iron Deficiency Anaemia

LENUS (Irish Health Repository)

McGrath, T

2018-01-01

We describe the case of a 17-month-old boy with a hypochromic microcytic anaemia, refractory to oral iron treatment. After exclusion of dietary and gastrointestinal causes of iron deficiency, a genetic cause for iron deficiency was confirmed by finding two mutations in the TMPRSS6 gene, consistent with a diagnosis of iron-refractory iron deficiency anaemia (IRIDA).

Effects of Temperature, Oxygen Partial Pressure, and Materials Selection on Slag Infiltration into Porous Refractories for Entrained-Flow Gasifiers

Science.gov (United States)

Kaneko, Tetsuya Kenneth

The penetration rate of molten mineral contents (slag) from spent carbonaceous feedstock into porous ceramic-oxide refractory linings is a critical parameter in determining the lifecycle of integrated gasification combined cycle energy production plants. Refractory linings that withstand longer operation without interruption are desirable because they can mitigate consumable and maintenance costs. Although refractory degradation has been extensively studied for many other high-temperature industrial processes, this work focuses on the mechanisms that are unique to entrained-flow gasification systems. The use of unique feedstock mixtures, temperatures from 1450 °C to 1600 °C, and oxygen partial pressures from 10-7 atm to 10-9 atm pose engineering challenges in designing an optimal refractory material. Experimentation, characterization, and modeling show that gasifier slag infiltration into porous refractory is determined by interactions between the slag and the refractory that either form a physical barrier that impedes fluid flow or induce an increased fluid viscosity that decelerates the velocity of the fluid body. The viscosity of the slag is modified by the thermal profile of the refractory along the penetration direction as well as reactions between the slag and refractory that alter the chemistry, and thereby the thermo-physical properties of the fluid. Infiltration experiments reveal that the temperature gradient inherently present along the refractory lining limits penetration. A refractory in near-isothermal conditions demonstrates deeper slag penetration as compared to one that experiences a steeper thermal profile. The decrease in the local temperatures of the slag as it travels deeper into the refractory increases the viscosity of the fluid, which in turn slows the infiltration velocity of fluid body into the pores of the refractory microstructure. With feedstock mixtures that exhibit high iron-oxide concentrations, a transition-metal-oxide, the oxygen

Direct brazing of ceramics, graphite, and refractory metals

International Nuclear Information System (INIS)

Canonico, D.A.; Cole, N.C.; Slaughter, G.M.

1976-03-01

ORNL has been instrumental in the development of brazing filler metals for joining ceramics, graphite, and refractory metals for application at temperatures above 1000 0 C. The philosophy and techniques employed in the development of these alloys are presented. A number of compositions are discussed that have been satisfactorily used to braze ceramics, graphite, and refractory metals without a prior surface treatment. One alloy, Ti--25 percent Cr--21 percent V, has wet and flowed on aluminum oxide and graphite. Further, it has been utilized in making brazes between different combinations of the three subject materials. The excellent flowability of this alloy and alloys from the Ti--Zr--Ge system is evidenced by the presence of filler metal in the minute pores of the graphite and ceramics

Mixed Uranium/Refractory Metal Carbide Fuels for High Performance Nuclear Reactors

International Nuclear Information System (INIS)

Knight, Travis; Anghaie, Samim

2002-01-01

Single phase, solid-solution mixed uranium/refractory metal carbides have been proposed as an advanced nuclear fuel for advanced, high-performance reactors. Earlier studies of mixed carbides focused on uranium and either thorium or plutonium as a fuel for fast breeder reactors enabling shorter doubling owing to the greater fissile atom density. However, the mixed uranium/refractory carbides such as (U, Zr, Nb)C have a lower uranium densities but hold significant promise because of their ultra-high melting points (typically greater than 3700 K), improved material compatibility, and high thermal conductivity approaching that of the metal. Various compositions of (U, Zr, Nb)C were processed with 5% and 10% metal mole fraction of uranium. Stoichiometric samples were processed from the constituent carbide powders, while hypo-stoichiometric samples with carbon-to-metal (C/M) ratios of 0.92 were processed from uranium hydride, graphite, and constituent refractory carbide powders. Processing techniques of cold uniaxial pressing, dynamic magnetic compaction, sintering, and hot pressing were investigated to optimize the processing parameters necessary to produce high density (low porosity), single phase, solid-solution mixed carbide nuclear fuels for testing. This investigation was undertaken to evaluate and characterize the performance of these mixed uranium/refractory metal carbides for high performance, ultra-safe nuclear reactor applications. (authors)

Approaches to refractory epilepsy

Directory of Open Access Journals (Sweden)

Jerome Engel

2014-01-01

Full Text Available Epilepsy is one of the most common serious neurological conditions, and 30 to 40% of people with epilepsy have seizures that are not controlled by medication. Patients are considered to have refractory epilepsy if disabling seizures continue despite appropriate trials of two antiseizure drugs, either alone or in combination. At this point, patients should be referred to multidisciplinary epilepsy centers that perform specialized diagnostic testing to first determine whether they are, in fact, pharmacoresistant, and then, if so, offer alternative treatments. Apparent pharmacoresistance can result from a variety of situations, including noncompliance, seizures that are not epileptic, misdiagnosis of the seizure type or epilepsy syndrome, inappropriate use of medication, and lifestyle issues. For patients who are pharmacoresistant, surgical treatment offers the best opportunity for complete freedom from seizures. Surgically remediable epilepsy syndromes have been identified, but patients with more complicated epilepsy can also benefit from surgical treatment and require more specialized evaluation, including intracranial EEG monitoring. For patients who are not surgical candidates, or who are unwilling to consider surgery, a variety of other alternative treatments can be considered, including peripheral or central neurostimulation, ketogenic diet, and complementary and alternative approaches. When such alternative treatments are not appropriate or effective, quality of life can still be greatly improved by the psychological and social support services offered by multidisciplinary epilepsy centers. A major obstacle remains the fact that only a small proportion of patients with refractory epilepsy are referred for expert evaluation and treatment.

Refractory overactive bladder: Beyond oral anticholinergic therapy

Science.gov (United States)

Glinski, Ronald W.; Siegel, Steven

2007-01-01

Objectives: In this review, we discuss the treatment of refractory overactive bladder (OAB) that has not adequately responded to medication therapy and we propose an appropriate care pathway to the treatment of OAB. We also attempt to address the cost of OAB treatments. Materials and Methods: A selective expert review of the current literature on the subject of refractory OAB using MEDLINE was performed and the data is summarized. We also review our experience in treating refractory OAB. The role and outcomes of various treatment options for refractory OAB are discussed and combined therapy with oral anticholinergics is explored. Emerging remedies including intravesical botulinum toxin injection and pudendal neuromodulation are also reviewed, along with conventional surgical options. Results: In general behavioral therapy, pelvic floor electrical stimulation, magnetic therapy and posterior tibial nerve stimulation (PTNS), have shown symptom decreases in 50-80% of patients with OAB. Depending on the study, combination therapy with oral anticholinergics seems to improve efficacy of behavioral therapy and PTNS in approximately 10-30%. In multicenter, long-term randomized controlled trials, sacral neuromodulation has been shown to improve symptoms of OAB and OAB incontinence in up to 80% of the patients treated. Studies involving emerging therapies such as pudendal serve stimulation suggest that there may be a 15-20% increase in efficacy over sacral neuromodulation, but long-term studies are not yet available. Another emerging therapy, botulinum toxin, is also showing similar success in reducing OAB symptoms in 80-90% of patients. Surgical approaches, such as bladder augmentation, are a last resort in the treatment of OAB and are rarely used at this point unless upper tract damage is a concern and all other treatment options have been exhausted. Conclusion: The vast majority of OAB patients can be managed successfully by behavioral options with or without

Refractory overactive bladder: Beyond oral anticholinergic therapy

Directory of Open Access Journals (Sweden)

Ronald W Glinski

2007-01-01

Full Text Available Objectives: In this review, we discuss the treatment of refractory overactive bladder (OAB that has not adequately responded to medication therapy and we propose an appropriate care pathway to the treatment of OAB. We also attempt to address the cost of OAB treatments. Materials and Methods: A selective expert review of the current literature on the subject of refractory OAB using MEDLINE was performed and the data is summarized. We also review our experience in treating refractory OAB. The role and outcomes of various treatment options for refractory OAB are discussed and combined therapy with oral anticholinergics is explored. Emerging remedies including intravesical botulinum toxin injection and pudendal neuromodulation are also reviewed, along with conventional surgical options. Results: In general behavioral therapy, pelvic floor electrical stimulation, magnetic therapy and posterior tibial nerve stimulation (PTNS, have shown symptom decreases in 50-80% of patients with OAB. Depending on the study, combination therapy with oral anticholinergics seems to improve efficacy of behavioral therapy and PTNS in approximately 10-30%. In multicenter, long-term randomized controlled trials, sacral neuromodulation has been shown to improve symptoms of OAB and OAB incontinence in up to 80% of the patients treated. Studies involving emerging therapies such as pudendal serve stimulation suggest that there may be a 15-20% increase in efficacy over sacral neuromodulation, but long-term studies are not yet available. Another emerging therapy, botulinum toxin, is also showing similar success in reducing OAB symptoms in 80-90% of patients. Surgical approaches, such as bladder augmentation, are a last resort in the treatment of OAB and are rarely used at this point unless upper tract damage is a concern and all other treatment options have been exhausted. Conclusion: The vast majority of OAB patients can be managed successfully by behavioral options with or

Enhancement of Dielectric Constant of Graphene-Epoxy Composite by Inclusion of Nanodiamond Particles

Science.gov (United States)

Khurram, A. A.; ul-Haq, Izhar; Khan, Ajmal; Hussain, Rizwan; Gul, I. H.

2018-02-01

The dielectric properties of a graphene-epoxy composite have been enhanced by filling with nanodiamond particles (NDPs) as secondary filler along with graphene nanoplatelets (GNPs). The epoxy composite filled with only NDPs or GNPs to 0.1 wt.%, 0.3 wt.%, and 0.5 wt.% exhibited smaller dielectric constant compared with when filled with both. Hybrid epoxy composites were prepared with inclusion of both fillers to 0.05 + 0.05 = 0.1 wt.%, 0.15 + 0.15 = 0.3 wt.%, and 0.25 + 0.25 = 0.5 wt.%. Inclusion of NDPs in addition to GNPs also improved the dispersion of the latter in solution, which is attributable to kinetic energy transfer to GNPs and screening of van der Waals forces between GNPs. The enhanced dielectric constant after inclusion of NDPs is due to improved dispersion of GNPs in the epoxy matrix, which may increase the interfacial polarization.

Development of diagnosis and repair system for steelmaking refractories; Seikoyo taikabutsu no shindan hoshu gijutsu no kakuritsu

Energy Technology Data Exchange (ETDEWEB)

Aso, S.; Harada, S.; Tsutsui, Y. [Nippon Steel Corp., Tokyo (Japan)

1996-06-01

The latest measurement equipment and repair method were introduced into the work area of all refractories in the process of torpedo cars, hot metal preliminary treatment, hot metal pans, secondary refining, and cast pans so as to improve the cost of the newest advanced steelmaking refractories. As a result, the refractory cost could be reduced by 10%. This paper introduces the improvement in RH refractories and refractories for hot metal preliminary treatment. As for basic items, in addition to the visual observation, the thickness of refractories was quantified using equipment (laser profile meter, thermotracer, and NS sensor) for the furnace stop in the minimum remaining length. An ITV was also installed in the facilities where the visual check is difficult to carry out. Repair is mainly done by spraying. A thermal spraying repair method with high durability was used for the repair. A method that relieves a thermal shock was used for preheating. Moreover, measures that make the temperature gradient in the thickness direction uniform by using newly developed microwave drying equipment were taken for drying of unburned refractories. 4 refs., 13 figs., 2 tabs.

Bone hydatid disease refractory to nitazoxanide treatment

NARCIS (Netherlands)

Schipper, Hans G.; Simsek, Suat; van Agtmael, Michiel A.; van Lienden, Krijn P.

2009-01-01

We report a patient with bone hydatid disease that was refractory to both long-term daily treatment with albendazole, combined with cimetidine or administered as monotherapy ( approximately 15 years) and a relatively short course of nitazoxanide combined with albendazole (3 months). Despite

Toll-like receptor 2 expression in refractory periapical lesions.

Science.gov (United States)

Desai, S V; Love, R M; Rich, A M; Seymour, G J

2011-10-01

To investigate the expression of TLR2 in refractory periapical lesions. Refractory periapical lesion biopsies were histopathologically and clinically categorized into asymptomatic periapical granuloma (n=10), symptomatic periapical granuloma (n=10) or periapical cyst (n=10) and prepared for immunohistochemical staining using antibodies to TLR2, CD3 and CD19 or staining with methyl green pyronin. Sections were viewed under light microscopy and the presence or absence of the target cells was correlated with the histopathological and clinical data. Additionally, TLR2 expression was quantified by counting TLR(+) cells. Various mononuclear inflammatory cells in the bacteria-induced periapical lesions were reactive to TLR2 antibody, with many showing morphological similarities to lymphocytes and plasma cells. Lymphocytes were the most numerous cells in the inflammatory infiltrate. In refractory periapical granuloma, CD3(+) T cells were more numerous, whereas in periapical cysts, CD19(+) B cells were more numerous. There was a statistically significant (Pperiapical granuloma than asymptomatic periapical granuloma or periapical cyst. The presence of TLR-expressing cells in periapical granulomas and cysts provides further evidence that periapical cysts are likely to be sustained by the immune system via reaction to bacterial antigens. © 2011 International Endodontic Journal.

Morphometric brain characterization of refractory obsessive-compulsive disorder: diffeomorphic anatomic registration using exponentiated Lie algebra.

Science.gov (United States)

Tang, Wanjie; Li, Bin; Huang, Xiaoqi; Jiang, Xiaoyu; Li, Fei; Wang, Lijuan; Chen, Taolin; Wang, Jinhui; Gong, Qiyong; Yang, Yanchun

2013-10-01

Few studies have used neuroimaging to characterize treatment-refractory obsessive-compulsive disorder (OCD). This study sought to explore gray matter structure in patients with treatment-refractory OCD and compare it with that of healthy controls. A total of 18 subjects with treatment-refractory OCD and 26 healthy volunteers were analyzed by MRI using a 3.0-T scanner and voxel-based morphometry (VBM). Diffeomorphic anatomical registration using exponentiated Lie algebra (DARTEL) was used to identify structural changes in gray matter associated with treatment-refractory OCD. A partial correlation model was used to analyze whether morphometric changes were associated with Yale-Brown Obsessive-Compulsive Scale scores and illness duration. Gray matter volume did not differ significantly between the two groups. Treatment-refractory OCD patients showed significantly lower gray matter density than healthy subjects in the left posterior cingulate cortex (PCC) and mediodorsal thalamus (MD) and significantly higher gray matter density in the left dorsal striatum (putamen). These changes did not correlate with symptom severity or illness duration. Our findings provide new evidence of deficits in gray matter density in treatment-refractory OCD patients. These patients may show characteristic density abnormalities in the left PCC, MD and dorsal striatum (putamen), which should be verified in longitudinal studies. © 2013. Published by Elsevier Inc. All rights reserved.

Thermal and electronic charge transport in bulk nanostructured Zr0.25Hf0.75NiSn composites with full-Heusler inclusions

International Nuclear Information System (INIS)

Makongo, Julien P.A.; Misra, Dinesh K.; Salvador, James R.; Takas, Nathan J.; Wang, Guoyu; Shabetai, Michael R.; Pant, Aditya; Paudel, Pravin; Uher, Ctirad; Stokes, Kevin L.; Poudeu, Pierre F.P.

2011-01-01

Bulk Zr 0.25 Hf 075 NiSn half-Heusler (HH) nanocomposites containing various mole fractions of full-Heusler (FH) inclusions were prepared by solid state reaction of pre-synthesized HH alloy with elemental Ni at 1073 K. The microstructures of spark plasma sintered specimens of the HH/FH nanocomposites were investigated using transmission electron microscopy and their thermoelectric properties were measured from 300 K to 775 K. The formation of coherent FH inclusions into the HH matrix arises from solid-state Ni diffusion into vacant sites of the HH structure. HH(1-y)/FH(y) composites with mole fraction of FH inclusions below the percolation threshold, y∼0.2, show increased electrical conductivity, reduced Seebeck coefficient and increased total thermal conductivity arising from gradual increase in the carrier concentration for composites. A drastic reduction (∼55%) in κ l was observed for the composite with y=0.6 and is attributed to enhanced phonon scattering due to mass fluctuations between FH and HH, and high density of HH/FH interfaces. - Graphical abstract: Large reduction in the lattice thermal conductivity of bulk nanostructured half-Heusler/full-Heusler (Zr 0.25 Hf 075 NiSn/ Zr 0.25 Hf 075 Ni 2 Sn) composites, obtained by solid-state diffusion at 1073 K of elemental Ni into vacant sites of the half-Heusler structure, arising from the formation of regions of spinodally decomposed HH and FH phases with a spatial composition modulation of ∼2 nm. Highlights: → Bulk composites from solid state transformation of half-Heusler matrix through Ni diffusion. → Formation of coherent phase boundaries between half-Heusler matrix and full-Heusler inclusion. → Alteration of thermal and electronic transports with increasing full-Heusler inclusion. → Enhanced phonon scattering at half-Heusler/ full-Heusler phase boundaries.

Niobium-Matrix-Composite High-Temperature Turbine Blades

Science.gov (United States)

Kaplan, Richard B.; Tuffias, Robert H.; La Ferla, Raffaele; Heng, Sangvavann; Harding, John T.

1995-01-01

High-temperture composite-material turbine blades comprising mainly niobium matrices reinforced with refractory-material fibers being developed. Of refractory fibrous materials investigated, FP-AL(2)0(3), tungsten, and polymer-based SiC fibers most promising. Blade of this type hollow and formed in nearly net shape by wrapping mesh of reinforcing refractory fibers around molybdenum mandrel, then using thermal-gradient chemical-vapor infiltration (CVI) to fill interstices with niobium. CVI process controllable and repeatable, and kinetics of both deposition and infiltration well understood.

Sorption techniques for production of high purity refractory metals

International Nuclear Information System (INIS)

Shatalov, V.V.; Peganov, V.A.; Logvinenko, I.A.; Molchanova, T.V.

2004-01-01

A consideration is given to potentialities of sorption processes tot provide a high quality of refractory metal and their alloys when using hydrometallurgical methods for raw material processing. The efficiency of application of ion exchange technology is shown for complex solutions reprocessing for various types of polymetallic raw materials, among them uranium ores, enriched concentrates of refractory metal ores, intermediate products, waste solutions. Based on investigation results on the behaviour of elements in process solutions and the mechanism of their sorption and elution, the process of pure chemical compounds production are developed which provide thereafter manufacturing compact metals. The flowsheets developed are mastered on a commercial scale [ru

Response to parenteral iron therapy distinguish unexplained refractory iron deficiency anemia from iron-refractory iron deficiency anemia.

Science.gov (United States)

Akin, M; Sarbay, H; Guler, S; Balci, Y I; Polat, A

2016-04-01

We evaluated that response to parenteral iron therapy could be helpful in distinguishing the types of iron deficiency anemia. This study analyzed responses to IV iron sucrose therapy of 15 children with unexplained refractory iron deficiency anemia (URIDA). We compared the results at diagnosis, 6 weeks and 6 months after the therapy. Results were compared with responses of 11 patients' results with iron-refractory iron deficiency anemia (IRIDA) from our previous study. Six weeks after the start of treatment, ferritin, MCV, MCH and Hb values were in normal range in 10 patients. The increase in Hb, MCH, MCV, and ferritin values ranged 2.6-3.5 g/dL, 1.7-4.2 pg, 2-9 fL, and 13-25 ng/mL, respectively. In five patients, Hb, MCH, and MCV mean (range) values [11.2 g/dL (11-12.2), 24.5 pg (24-25.6), and 67 fL (65-70)] were nearly normal but ferritin mean (range) values [9.8 ng/mL (8-11)] were below normal. Six weeks after the start of treatment, Hb, MCH, MCV and ferritin values of patients with IRIDA were increased. The increase in Hb, MCH, MCV, and ferritin values ranged 0.8-2.7 g/dL, 1.7-4.2 pg, 2-9 fL, and 13-25 ng/mL, respectively. IRIDA is only partially responsive to parenteral iron supplementation. In conclusion, this study demonstrated that the response to intravenous iron therapy for the URIDA cases improved blood parameters more effectively than hereditary IRIDA. Response to parenteral iron therapy would be helpful to distinguish unexplained refractory IDA from hereditary IRIDA for clinicians who do not have access to hepcidin or TMPRS6 mutation analysis. © 2016 John Wiley & Sons Ltd.

Low-temperature plasma spheroidizing of polydisperse powders of refractory materials

International Nuclear Information System (INIS)

Tsymbalist, M.M.; Rudenskaya, N.A.; Kuz'min, B.P.; Pan'kov, V.A.

2003-01-01

A model is developed for heating and melting of a spherical particle, when powder processing in low temperature plasma, with the aim of estimation of the dependence of the degree of fusion on particle size for various materials. Spheroidizing of various refractory material powders close in shape and size composition is experimentally performed. Experimental and calculation estimates of spheroidizing criteria for the materials studied are in a satisfactory agreement. The influence of basic physical properties of refractory materials and plasma processing parameters on the degree of particle spheroidizing is analyzed [ru

Confronting New Demands : Inclusive Growth, Inclusive Trade ...

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

Confronting New Demands : Inclusive Growth, Inclusive Trade. Policymakers, businesspeople and civil society advocates need evidence-based research to react ... understood implications, such as labour standards and intellectual property; ...

Colonic exclusion and combined therapy for refractory constipation.

Science.gov (United States)

Peng, Hong-Yun; Xu, Ai-Zhong

2006-12-28

To investigate the therapeutic effectiveness of colonic exclusion and combined therapy for refractory constipation. Thirty-two patients with refractory constipation were randomly divided into treatment group (n = 14) and control group (n = 18). Fourteen patients in treatment group underwent colonic exclusion and end-to-side colorectal anastomosis. Eighteen patients in control group received subtotal colectomy and end-to-end colorectal anastomosis. The therapeutic effects of the operations were assessed by comparing the surgical time, incision length, volume of blood losses, hospital stay, recovery rate and complication incidence. All patients received long-term follow-up. All operations were successful and patients recovered fully after the operations. In comparison of treatment group and control group, the surgical time (h), incision length (cm), volume of blood losses (mL), hospital stay (d) were 87 +/- 16 min vs 194 +/- 23 min (t = 9.85), 10.4 +/- 0.5 cm vs 21.2 +/- 1.8 cm (t = 14.26), 79.5 +/- 31.3 mL vs 286.3 +/- 49.2 mL (t = 17.24), and 11.8 +/- 2.4 d vs 18.6 +/- 2.6 d (t = 6.91), respectively (P 0.05), 21.4% vs 33.3% (P = 0.73 > 0.05), respectively. Colonic exclusion has better therapeutic efficacy on refractory constipation. It has many advantages such as shorter surgical time, smaller incision, fewer blood losses and shorter hospital stay.

The R-matrix investigation of 8Li(α, n)11B reaction below 6 MeV

Science.gov (United States)

Kilic, Ali Ihsan; Muecher, Dennis; Garret, Paul; Svensson, Carl

2017-09-01

The investigation of cross sections for the 8Li(α, n)11B reaction has important impact for both primordial nucleosynthesis in the inhomogeneous models as well as constraining the physical conditions characterizing the r-process. However, there are large discrepancies existing between inclusive and exclusive measurements of the cross section below 3 MeV. The R-Matrix technique is a powerful tool for the analysis of the nuclear data for the purpose of extracting level information of compound nucleus 12B and extrapolation of the astrophysical S-Factor to Gamow energies. We have applied the R-matrix calculations for the 8Li(α, n)11B reaction and will present results for both the reaction rates and the partial S-factor. Combining the direct reaction contribution with the results from our R-matrix calculations, we can well describe the experimental data from the inclusive measurements. However, new experiments are needed in order to understand the role of neutron detection close to the threshold, for which we describe our experimental plans at ISAC, TRIUMF, using the newly developed DESCANT array.

Developing a financial inclusion index and inclusive growth in India

OpenAIRE

Susanta Kumar SETHY

2016-01-01

Financial inclusion is one of the systems through which Inclusive Growth can be achieved in developing countries like India where large sections are unable or hopeless to contribute in the financial system. An inclusive financial system mobilizes more resources for productive purposes leading to higher economic growth, better opportunities and reduction of poverty. This study, proposed an Index of financial inclusion – a multidimensional measure. The Financial Inclusion Index c...

Lightweight cordierite–mullite refractories with low coefficients of ...

Indian Academy of Sciences (India)

of thermal conductivity and high mechanical properties ... compositions and microstructures of lightweight refractories were measured by X-ray .... of matrices were determined by calibration with EDAX ZAF .... Guzman I Ya 2003 Glass Ceram.

Antipsychotic Polypharmacy in a Treatment-Refractory Schizophrenia Population Receiving Adjunctive Treatment With Electroconvulsive Therapy

DEFF Research Database (Denmark)

Kristensen, Diana; Hageman, Ida; Bauer, Jeanett

2013-01-01

Antipsychotic polypharmacy (APP) is frequent, but its pattern is unknown in treatment-refractory schizophrenia-spectrum patients receiving electroconvulsive therapy (ECT).......Antipsychotic polypharmacy (APP) is frequent, but its pattern is unknown in treatment-refractory schizophrenia-spectrum patients receiving electroconvulsive therapy (ECT)....

EFFICACY OF RECURRENT RITUXIMAB TREATMENT IN PATIENT WITH SEVERE REFRACTORY SYSTEMIC JUVENILE RHEUMATOID ARTHRITIS

Directory of Open Access Journals (Sweden)

E.I. Alexeeva

2011-01-01

Full Text Available The article contains clinical case description of a severe systemic juvenile rheumatoid arthritis, that was refractory to classic immunosuppressant therapy. The disease was characterized by such extraarticular manifestations as fever, lymphadenopathy,  hepatosplenomegaly, polyserositis, generalized joint involvement and high activity in lab tests. As a result of severe clinical course of the disease, patients develop bilateral aseptic bone necrosis in coxofemoral joints and coxarthrosis. Against the background of glucocorticosteroid treatment the patient has developed hormone-dependency and hormone resistance. Inclusion into the treatment of anti-CD20 monoclonal antibodies (rituximab has stopped systemic manifestations of the disease, inflammation in the joints, normalized lab activity rates. The positive therapeutic effect allowed to perform surgery due to bilateral coxarthrosis. These results show that rituximab is highly effective in children with systemic juvenile rheumatoid arthritis, that is resistant to classic immunosupressants and glucocorticoides. Key words: children, systemic juvenile rheumatoid arthritis, rituximab, recurrent treatment, prosthetics, hip joint. (Voprosy sovremennoi pediatrii — Current Pediatrics. — 2011; 10 (5: 157–163.

Field assisted sintering of refractory carbide ceramics and fiber reinforced ceramic matrix composites

Science.gov (United States)

Gephart, Sean

The sintering behaviors of silicon carbide (SiC) and boron carbide (B4C) based materials were investigated using an emerging sintering technology known as field assisted sintering technology (FAST), also known as spark plasma sintering (SPS) and pulse electric current sintering (PECS). Sintering by FAST utilizes high density electric current, uniaxial pressure, and relatively high heating rate compared to conventional sintering techniques. This effort investigated issues of scaling from laboratory FAST system (25 ton capacity) to industrial FAST system (250 ton capacity), as well as exploring the difference in sintering behavior of single phase B4C and SiC using FAST and conventional sintering techniques including hot-pressing (HP) and pressure-less sintering (PL). Materials were analyzed for mechanical and bulk properties, including characterization of density, hardness, fracture toughness, fracture (bend) strength, elastic modulus and microstructure. A parallel investigation was conducted in the development of ceramic matrix composites (CMC) using SiC powder impregnation of fiber compacts followed by FAST sintering. The FAST technique was used to sinter several B4C and SiC materials to near theoretical density. Preliminary efforts established optimized sintering temperatures using the smaller 25 ton laboratory unit, targeting a sample size of 40 mm diameter and 8 mm thickness. Then the same B4C and SiC materials were sintered by the larger 250 ton industrial FAST system, a HP system, and PL sintering system with a targeted dense material geometry of 4 x 4 x 0.315 inches3 (101.6 x 101.6 x 8 mm3). The resulting samples were studied to determine if the sintering dynamics and/or the resulting material properties were influenced by the sintering technique employed. This study determined that FAST sintered ceramic materials resulted in consistently higher averaged values for mechanical properties as well as smaller grain size when compared to conventionally sintered

Effect of Deoxidation Process on Inclusion and Fatigue Performance of Spring Steel for Automobile Suspension

Science.gov (United States)

Hu, Yang; Chen, Weiqing; Wan, Changjie; Wang, Fangjun; Han, Huaibin

2018-04-01

55SiCrA spring steel was smelted in a vacuum induction levitation furnace. The liquid steel was treated by Si deoxidation, Al modification with Ca treatment and Al modification, and the steel samples were obtained with deformable Al2O3-SiO2-CaO-MgO inclusions closely contacted with steel matrix, Al2O3-CaO-CaS-SiO2-MgO inclusions surrounded by small voids or Al2O3(> 80 pct)-SiO2-CaO-MgO inclusions surrounded by big voids, respectively. Effect of three types of inclusions on steel fatigue cracks was studied. The perpendicular and transverse fatigue cracks around the three types of inclusions leading to fracture were found to vary in behavior. Under the applied stress amplitude of 775 MPa, the fatigue lives of the three spring steels decreased from 4.0 × 107 to 3.8 × 107, and to 3.1 × 107 cycles. For the applied stress amplitude of 750 MPa, the fatigue lives of the three spring steels decreased from 5.2 × 107 to 4.1 × 107, and to 3.4 × 107 cycles. Based on the voids around inclusions, the equivalent size of initial fatigue crack has been newly defined as √ {{{area}_{inclusion} }/{(1 - {CC)}}} , where the contraction coefficient CC of inclusion was introduced. A reliable forecast model of the critical size of inclusion leading to fracture was established by the incorporation of actual width b inclusion or diameter d inclusion of internal inclusion; the model prediction was found to be in agreement with experimental results.

Microstructure investigation of NiAl-Cr(Mo) interface in a directionally solidified NiAl-Cr(Mo) eutectic alloyed with refractory metal

International Nuclear Information System (INIS)

Chen, Y.X.; Cui, C.Y.; Guo, J.T.; Li, D.X.

2004-01-01

The microstructure of a directionally solidified NiAl-Cr(Mo) eutectic alloyed with refractory metal in as-processed and heat-treated states has been studied by means of scanning electron microscopy and high resolution electron microscopy (HREM). The microstructure of the NiAl-Cr(Mo) eutectic was characterized by lamellar Cr(Mo) phases embedded within NiAl matrix with common growth direction of . The interface between NiAl and lamellar Cr(Mo) did not have any transition layers. Misfit dislocations were observed at the NiAl-Cr(Mo) interface. In addition to lamellar Cr(Mo) phases, coherent Cr(Mo, Ni, Al) precipitates and NiAl precipitates were also observed in the NiAl matrix and lamellar Cr(Mo) phases, respectively. After hot isostatic pressing and heat treatment, the NiAl-Cr(Mo) interfaces became smooth and straight. Square array of misfit dislocations was directly observed at the (0 0 1) interface between NiAl and Cr(Mo, Ni, Al) precipitate. The configuration of misfit dislocation network showed a generally good agreement with prediction based on the geometric O-lattice model

Morphological differentiation of severe aplastic anaemia from hypocellular refractory cytopenia of childhood

DEFF Research Database (Denmark)

Baumann, Irith; Führer, Monika; Behrendt, Sonja

2012-01-01

To evaluate the reproducibility and reliability of the histomorphological criteria differentiating severe aplastic anaemia (SAA) and hypoplastic refractory cytopenia of childhood (RCC), the most frequently acquired hypocellular bone marrow conditions of childhood.......To evaluate the reproducibility and reliability of the histomorphological criteria differentiating severe aplastic anaemia (SAA) and hypoplastic refractory cytopenia of childhood (RCC), the most frequently acquired hypocellular bone marrow conditions of childhood....

Advances in multidisciplinary individualized treatment of refractory hepatic alveolar echinococcosis

Directory of Open Access Journals (Sweden)

ABUDUAINI Abulizi

2015-04-01

Full Text Available Hepatic alveolar echinococcosis (HAE is a zoonotic parasitic disease that seriously threatens the population in western China and compromises patients′ quality of life. With the continuous improvement in radical resection rate in recent years, late-stage HAE patients that were incurable in the past now have the opportunity for radical resection. However, patients who are not suitable candidates for radical resection still suffer from various complications and poor quality of life. Therefore, HAE is still considered a refractory and complex disease. The simple empirical treatment model provided by traditional professional discussion is unable to satisfy the treatment of advanced refractory HAE as it is unable to integrate specialized, standardized clinical skills for diagnosis and treatment. Multidisciplinary individualized treatment (MDT organically integrates the advantages of the available treatment into a reasonable individualized comprehensive treatment regimen. This review summarizes the advances in MDT for HAE as the best option to increase long-term survival, and suggests MDT as the first-line treatment for late-stage refractory hepatic alveolar echinococcosis.

Immunomodulatory therapy in refractory/recurrent ovarian cancer

Directory of Open Access Journals (Sweden)

Chao-Yu Chen

2015-04-01

Conclusion: IMT alone or add-on to palliative/salvage chemotherapy for refractory/recurrent EOC achieves a substantial disease stabilizing rate without severe toxicity, which might be a potential option in selected patients. The ALC 1 month after IMT could be an early indicator to disease stabilization.

Decision Making during the Psychological Refractory Period

NARCIS (Netherlands)

Zylberberg, Ariel; Ouellette, Brian; Sigman, Mariano; Roelfsema, Pieter R.

2012-01-01

In spite of its massively parallel architecture [1], the human brain is fundamentally limited if required to perform two tasks at the same time [2, 3]. This limitation can be studied with the psychological refractory period (PRP) paradigm, where two stimuli that require speeded responses occur in

On the continuous selections of solution sets of Lipschitzian quantum stochastic differential inclusions

International Nuclear Information System (INIS)

Ayoola, E.O.

2004-05-01

We prove that a multifunction associated with the set of solutions of Lipschitzian quantum stochastic differential inclusion (QSDI) admits a selection continuous from some subsets of complex numbers to the space of the matrix elements of adapted weakly absolutely continuous quantum stochastic processes. In particular, we show that the solution set map as well as the reachable set of the QSDI admit some continuous representations. (author)

Ways to improve physical and thermal performance of refractory lining materials

Directory of Open Access Journals (Sweden)

Khlystov A.I.

2017-01-01

Full Text Available Refractory lining materials, which include ceramic refractories and nonfired heat-resistant concretes, have a very short lifespan during the turnaround time measured in years and sometimes months. Therefore, increasing the service life of thermal generating units by 1.5-2 times will bring significant economic benefits. The main factor that determines the durability of refractory lining materials is the thermal resistance. It is possible to increase the thermal resistance by improving such physical and mechanical properties as strength and density. As for the ceramic refractory performance improvement, such technological methods as their structural and chemical modification by phosphate binder impregnation, as well as introduction of phosphate components into the ceramic batches during the molding process increase, in particular, their thermal stability. The use of aluminous and high-alumina cements contributes to a significant increase of not only strength, but also physical and thermal performance of heat-resistant concretes with different fillers. Switching to the use of chemical binders in the compositions of heat-resistant concretes (liquid glass with effective hardeners; silicate-block and phosphate binders enables to develop high-heat resistant materials which do not soften in a wide range of heating temperatures from 400 °С to 1600 °С. The positive results on increasing the thermal resistance of heat-resistant composites can be obtained by reinforcing them with high temperature fibers.

CAR-T cells and allogeneic hematopoietic stem cell transplantation for relapsed/refractory B-cell acute lymphoblastic leukemia.

Science.gov (United States)

Liu, Jun; Zhang, Xi; Zhong, Jiang F; Zhang, Cheng

2017-10-01

Relapsed/refractory acute lymphoblastic leukemia (ALL) has a low remission rate after chemotherapy, a high relapse rate and poor long-term survival even when allogeneic hematopoietic stem cell transplantation (allo-HSCT) is performed. Chimeric antigen receptors redirected T cells (CAR-T cells) can enhance disease remission with a favorable outcome for relapsed/refractory ALL, though some cases quickly relapsed after CAR-T cell treatment. Thus, treatment with CAR-T cells followed by allo-HSCT may be the best way to treat relapsed/refractory ALL. In this review, we first discuss the different types of CAR-T cells. We then discuss the treatment of relapsed/refractory ALL using only CAR-T cells. Finally, we discuss the use of CAR-T cells, followed by allo-HSCT, for the treatment of relapsed/refractory ALL.

Rate of primary refractory disease in B and T-cell non-Hodgkin's lymphoma: correlation with long-term survival.

Directory of Open Access Journals (Sweden)

Corrado Tarella

Full Text Available BACKGROUND: Primary refractory disease is a main challenge in the management of non-Hodgkin's Lymphoma (NHL. This survey was performed to define the rate of refractory disease to first-line therapy in B and T-cell NHL subtypes and the long-term survival of primary refractory compared to primary responsive patients. METHODS: Medical records were reviewed of 3,106 patients who had undergone primary treatment for NHL between 1982 and 2012, at the Hematology Centers of Torino and Bergamo, Italy. Primary treatment included CHOP or CHOP-like regimens (63.2%, intensive therapy with autograft (16.9%, or other therapies (19.9%. Among B-cell NHL, 1,356 (47.8% received first-line chemotherapy with rituximab. Refractory disease was defined as stable/progressive disease, or transient response with disease progression within six months. RESULTS: Overall, 690 (22.2% patients showed primary refractory disease, with a higher incidence amongst T-cell compared to B-cell NHL (41.9% vs. 20.5%, respectively, p<0.001. Several other clinico-pathological factors at presentation were variably associated with refractory disease, including histological aggressive disease, unfavorable clinical presentation, Bone Marrow involvement, low lymphocyte/monocyte ration and male gender. Amongst B-cell NHL, the addition of rituximab was associated with a marked reduction of refractory disease (13.6% vs. 26.7% for non-supplemented chemotherapy, p<0.001. Overall, primary responsive patients had a median survival of 19.8 years, compared to 1.3 yr. for refractory patients. A prolonged survival was consistently observed in all primary responsive patients regardless of the histology. The long life expectancy of primary responsive patients was documented in both series managed before and after 2.000. Response to first line therapy resulted by far the most predictive factor for long-term outcome (HR for primary refractory disease: 16.52, p<0.001. CONCLUSION: Chemosensitivity to primary

Clinical observation on Ahmed glaucoma valve implantation for teenagers with refractory glaucoma

Directory of Open Access Journals (Sweden)

Dong-Dao Song

2016-06-01

Full Text Available AIM:To observe the clinical effect of Ahmed glaucoma valve(AGVimplantation for teenagers with refractory glaucoma. METHODS: Twenty-seven patients(27 eyeswith refractory glaucoma were treated with AGV implantation in our hospital from October 2012 to October 2014. The patients were followed up for 12mo. The success rate of the operation, postoperative intraocular pressure, the best corrected visual acuity, as well as complications were recorded. RESULTS: The success rate of the operation was 85%. The intraocular pressure of the 27 patients decreased from 48.3±8.3mmHg before operations to 21.4±8.1mmHg(PPCONCLUSION: AGV implantation is characterized by a high success rate, simple operation, less complications and is an effective treatment for refractory glaucoma in adolescents.

Corrosion of K-3 glass-contact refractory in sodium-rich aluminosilicate melts

International Nuclear Information System (INIS)

Lu, X.D.; Gan, H.; Buechele, A.C.; Pegg, I.L.

1999-01-01

The corrosion of the glass-contact refractory Monofrax K-3 in two sodium-rich aluminosilicate melts has been studied at 1,208 and 1,283 C using a modified ASTM procedure with constant agitation of the melt by air bubbling. The results for the monolithic refractory indicate a fast initial stage involving phase dissolution and transformation and a later passivated stage in which the surface of the refractory has been substantially modified. The composition of the stable spinel phase in the altered layer on monolithic coupons of K-3 is almost identical to the equilibrium composition bracketed by the dissolution of powdered K-3 into under-saturated melts on the other. The temperature and melt shear viscosity were found to have significant effects on the rates of K-3 dissolution and transformation

Efficiency criterion for teleportation via channel matrix, measurement matrix and collapsed matrix

Directory of Open Access Journals (Sweden)

Xin-Wei Zha

Full Text Available In this paper, three kinds of coefficient matrixes (channel matrix, measurement matrix, collapsed matrix associated with the pure state for teleportation are presented, the general relation among channel matrix, measurement matrix and collapsed matrix is obtained. In addition, a criterion for judging whether a state can be teleported successfully is given, depending on the relation between the number of parameter of an unknown state and the rank of the collapsed matrix. Keywords: Channel matrix, Measurement matrix, Collapsed matrix, Teleportation

A retrospective study on the management of patients with rituximab refractory follicular lymphoma.

Science.gov (United States)

Solal-Céligny, Philippe; Leconte, Pierre; Bardet, Aurélie; Hernandez, Juana; Troussard, Xavier

2018-01-01

Given that there are currently no clear recommendations regarding therapeutic options for rituximab refractory/relapsed follicular lymphoma patients, this study aimed to describe the real-life management of patients with refractory follicular lymphoma after systemic rituximab-containing regimens (rFL), and rFL patient characteristics. In this retrospective, national, multicentre study, descriptive analyses were mainly performed according to rituximab-containing regimen at rFL diagnosis [rituximab monotherapy (R-MONO), rituximab + chemotherapy (R-COMBO), and ongoing rituximab maintenance (R-MAINTAIN)]. The 459 analysed patients experienced rituximab-refractoriness between October 2013 and September 2015: R-MONO: 58 (13%), R-COMBO: 197 (43%), R-MAINTAIN: 204 (44%). Post-refractoriness strategies were heterogeneous: idelalisib ± rituximab (22%), without anti-lymphoma treatment (21%), rituximab-chemotherapy (21%) and stem cell transplantation (18%). Rituximab was continued in combination in 41% of cases. Chosen strategies varied according to patient age (without anti-lymphoma treatment: 28% of patients if ≥65 years vs. 12% if management and for the design of clinical trials in these patients. © 2017 John Wiley & Sons Ltd.

Matrix effects in inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Chen, Xiaoshan.

1995-01-01

The inductively coupled plasma is an electrodeless discharge in a gas (usually Ar) at atmospheric pressure. Radio frequency energy generated by a RF power source is inductively coupled to the plasma gas through a water cooled load coil. In ICP-MS the open-quotes Fasselclose quotes TAX quartz torch commonly used in emission is mounted horizontally. The sample aerosol is introduced into the central flow, where the gas kinetic temperature is about 5000 K. The aerosol is vaporized, atomized, excited and ionized in the plasma, and the ions are subsequently extracted through two metal apertures (sampler and skimmer) into the mass spectrometer. In ICP-MS, the matrix effects, or non-spectroscopic interferences, can be defined as the type of interferences caused by dissolved concomitant salt ions in the solution. Matrix effects can be divided into two categories: (1) signal drift due to the deposition of solids on the sampling apertures; and/or (2) signal suppression or enhancement by the presence of the dissolved salts. The first category is now reasonably understood. The dissolved salts, especially refractory oxides, tend to deposit on the cool tip of the sampling cone. The clogging of the orifices reduces the ion flow into the ICP-MS, lowers the pressure in the first stage of ICP-MS, and enhances the level of metal oxide ions. Because the extent of the clogging increases with the time, the signal drifts down. Even at the very early stage of the development of ICP-MS, matrix effects had been observed. Houk et al. found out that the ICP-MS was not tolerant to solutions containing significant amounts of dissolved solids

New applications and novel processing of refractory metal alloys

International Nuclear Information System (INIS)

Briant, C.L.

2001-01-01

Refractory metals have often been limited in their application because of their propensity to oxidize and to undergo a loos of yield strength at elevated temperatures. However, recent developments in both processing and alloy composition have opened the possibility that these materials might be used in structural applications that were not considered possible in the past. At the same time, the use of refractory metals in the electronics industry is growing, particularly with the use of tantalum as a diffusion barrier for copper metallization. Finally, the application of grain boundary engineering to the problem of intergranular fracture in these materials may allow processes to be developed that will produce alloys with a greater resistance to fracture. (author)

Classical management of refractory adult immune (idiopathic) thrombocytopenic purpura.

Science.gov (United States)

McMillan, R

2002-03-01

Treatment of chronic immune (idiopathic) thrombocytopenic purpura with corticosteroids and/or splenectomy results in safe platelet counts in over 70% of patients without additional treatment. Therapy of patients who are refractory to these two treatments may be difficult. The treatment approach to refractory ITP patients, described in this report, is arbitrarily divided into four levels: levels 1 through 3 represent treatments with increasing side effects; level 4 therapy may be tried when the others have failed. Patients undergoing these treatments may require concomitant intravenous gammaglobulin, high-dose corticosteroids or platelets, to maintain the platelet count in the setting of mucosal bleeding or severe thrombocytopenia. Copyright 2002, Elsevier Science Ltd. All rights reserved.

Refractory Septic Shock Treated with Nephrectomy under the Support of Extracorporeal Membrane Oxygenation

Directory of Open Access Journals (Sweden)

Young Kun Lee

2015-08-01

Full Text Available Conventional medical therapies have not been very successful in treating adults with refractory septic shock. The effects of direct hemoperfusion using polymyxin B and veno-arterial extracorporeal membrane oxygenation (ECMO for refractory septic shock remain uncertain. A 66-year-old man was admitted to the emergency department and suffered from sepsis-induced hemodynamic collapse. For hemodynamic improvement, we performed direct hemoperfusion using polymyxin B. Computed tomography scan of this patient revealed emphysematous pyelonephritis (EPN, for which he underwent emergent nephrectomy with veno-arterial ECMO support. To the best of our knowledge, this is the first report of successful treatment of EPN with refractory septic shock using polymyxin B hemoperfusion and nephrectomy under the support of ECMO.

Origin of spinel lamella and/or inclusions in olivine of harzburgite form the Pauza ultramafic rocks from the Kurdistan region, northeastern Iraq

Science.gov (United States)

Mohammad, Y.; Maekawa, H.; Karim, K.

2009-04-01

Exsolution lamellae and octahedral inclusions of chromian spinel occur in olivine of harzburgite of the Pauza ultramafic rocks, Kurdistan region, northeastern Iraq. The lamella is up to 80μm long and up to 50 μm wide. The lamellae and octahedral inclusions of chromian spinel are distributed heterogeneously in the host olivine crystal. They are depleted in Al2O3 relative to the subhedral spinel grains in the matrix and spinel lamella in orthopyroxene. Olivine (Fo92 - 93) with spinel lamellae occurs as fine-grained crystals around orthopyroxene, whereas olivine (Fo90-91) free from spinel is found in matrix. Based on back-scattered images analyses, enrichments of both Cr # and Fe+3 in the chromian spinel lamella in olivine (replacive olivine) relative to that in adjacent orthopyroxene. As well as the compositions of chromian spinel lamellae host olivine are more Mg-rich than the matrix olivine. Furthermore the restriction of olivine with spinel lamellae and octahedral inclusions on around orthopyroxene, and the similarity of spinel lamella orientations in both olivine and adjacent orthopyroxene. This study concludes that the spinel inclusions in olivine are remnant (inherited from former orthopyroxene) spinel exsolution lamella in orthopyroxene, that has been formed in upper mantle conditions ( T = 1200 °C, P = 2.5 GPa ). Replacive olivine are formed by reaction of ascending silica poor melt and orthopyroxene in harzburgite as pressure decrease the solubility of silica-rich phase (orthopyroxene) in the system increase, therefore ascending melt dissolve pyroxene with spinel exsolution lamella and precipitate replacive olivine with spinel inclusions. We can conclude that the olivines with spinel lamella are not necessary to be original and presenting ultrahigh-pressure and/or ultra deep-mantle conditions as previously concluded. It has been formed by melting of orthopyroxene (orthopyroxene with spinel exsolution lamella = olivine with spinel lamellae and octahedral

Refractory concretes

International Nuclear Information System (INIS)

Holcombe, C.E. Jr.

1979-01-01

Novel concrete compositions comprise particles of aggregate material embedded in a cement matrix, said cement matrix produced by contacting an oxide selected from the group of Y 2 O 3 , La 2 O 3 , Nd 2 O 3 , Sm 2 O 3 , Eu 2 O 3 and Gd 2 O 3 with an aqueous solution of a salt selected from the group of NH 4 HO 3 , NH 4 Cl, YCl 3 and Mg(NO 3 ) 2 to form a fluid mixture; and allowing the fluid mixture to harden

Iatrogenic colorectal Kaposi sarcoma complicating a refractory ...

African Journals Online (AJOL)

Kaposi sarcoma is a mesenchymal tumor associated to a human herpes virus-8. It often occurs in human immunodeficiency virus-positive subjects. Colorectal localization is rare. We report the case of a colorectal Kaposi sarcoma complicating a refractory ulcerative colitis treated with surgery after the failure of ...

Efficacy and Safety of Rituximab in Children with Refractory Nephrotic Syndrome; A Multicenter Clinical Trial

Directory of Open Access Journals (Sweden)

Yo Han Ahn

2014-06-01

Conclusions: In this interim analysis of clinical trial to evaluate the efficacy and safety of RTX in children with refractory NS, RTX treatment for refractory NS was safe and effective, especially in patients with DNS.

Evaluation of nutritional status in children with refractory epilepsy.

Science.gov (United States)

Bertoli, S; Cardinali, S; Veggiotti, P; Trentani, C; Testolin, G; Tagliabue, A

2006-04-26

children affected by refractory epilepsy could be at risk of malnutrition because of feeding difficulties (anorexia, chewing, swallowing difficulties or vomiting) and chronic use of anticonvulsants, which may affect food intake and energy metabolism. Moreover, their energy requirement may be changed as their disabilities would impede normal daily activities. The aim of the present study was to evaluate nutritional status, energy metabolism and food intake in children with refractory epilepsy. 17 children with refractory epilepsy (13 boys and 4 girls; mean age 9 +/- 3,2 years; Body Mass Index 15,7 +/- 3,6) underwent an anthropometric assessment, body composition evaluation by dual-energy X-ray absorptiometry, detailed dietetic survey and measurement of resting energy expenditure by indirect calorimetry. Weight-for-age, height-for-age (stunting) and weight-for-height (wasting) were estimated compared to those of a reference population of the same age. 40% of children were malnourished and 24% were wasted. The nutritional status was worse in the more disabled children. Dietary intake resulted unbalanced (18%, 39%, 43% of total daily energy intake derived respectively from protein, lipid and carbohydrate). Adequacy index [nutrient daily intake/recommended allowance (RDA) x 100] was nutritional assessment and management as part of their overall care.

Adalimumab for the treatment of refractory noninfectious paediatric uveitis.

Science.gov (United States)

Muñoz-Gallego, Alicia; Barral, Estefanía; Enríquez, Eugenia; Tejada, Pilar; Barceló, Ana; de Inocencio, Jaime

2017-06-01

To report the experience of our center with the use of adalimumab (ADA) for the treatment of severe refractory noninfectious paediatric uveitis. The study is a retrospective case series of all paediatric patients with refractory uveitis who were treated with ADA at the Paediatric Uveitis Unit of our center from 2008 to 2015. We present 12 patients (6 Juvenile idiopathic arthritis-associated uveitis, 4 idiopathic panuveitis, 1 early-onset sarcoidosis-associated panuveitis, and 1 intermediate uveitis), with uveitis in 19/24 eyes. Once ADA therapy was started, all the patients presented improved activity according to Standardization of Uveitis Nomenclature (SUN) criteria. Nine out of the 12 patients had structural damage before ADA could be started: cataract (n = 4), glaucoma (n = 2), cystic macular edema (n = 1), exudative retinal detachment (n = 1), and optic disk edema (n = 5). Visual acuity improved or maintained stable in 17/19 affected eyes, and only 2 eyes decreased its visual acuity because of structural damage, which was already present before ADA therapy. In our experience, ADA presents a good safety profile and is efficacious in the treatment of paediatric patients with different forms of refractory noninfectious uveitis.

Evaluation of nutritional status in children with refractory epilepsy

Science.gov (United States)

Bertoli, S; Cardinali, S; Veggiotti, P; Trentani, C; Testolin, G; Tagliabue, A

2006-01-01

Background children affected by refractory epilepsy could be at risk of malnutrition because of feeding difficulties (anorexia, chewing, swallowing difficulties or vomiting) and chronic use of anticonvulsants, which may affect food intake and energy metabolism. Moreover, their energy requirement may be changed as their disabilities would impede normal daily activities. The aim of the present study was to evaluate nutritional status, energy metabolism and food intake in children with refractory epilepsy. Methods 17 children with refractory epilepsy (13 boys and 4 girls; mean age 9 ± 3,2 years; Body Mass Index 15,7 ± 3,6) underwent an anthropometric assessment, body composition evaluation by dual-energy X-ray absorptiometry, detailed dietetic survey and measurement of resting energy expenditure by indirect calorimetry. Weight-for-age, height-for-age (stunting) and weight-for-height (wasting) were estimated compared to those of a reference population of the same age. Results 40% of children were malnourished and 24% were wasted. The nutritional status was worse in the more disabled children. Dietary intake resulted unbalanced (18%, 39%, 43% of total daily energy intake derived respectively from protein, lipid and carbohydrate). Adequacy index [nutrient daily intake/recommended allowance (RDA) × 100] was nutritional assessment and management as part of their overall care. PMID:16640779

Study of Σ+-(1385) inclusive production in K-p interactions at 4.2 GeV/c

International Nuclear Information System (INIS)

Barreiro, F.; Berge, J.P.; Ganguli, S.N.; Gravillet, Ph.; Hemingway, R.J.; Blokzyl, R.; Kluijver, J.C.; Wolters, G.F.; Engelen, J.J.; Kittel, E.W.; Shephard, W.D.

1977-01-01

Properties of Σ +- (1385) inclusively produced in 4.2 GeV/c K - p interactions are studied. Inclusive cross sections are presented together with differential cross sections as functions of x and psub(t) 2 for both Σ + (1385) and Σ - (1385). The complete density matrix for Σ + (1385) production at small momentum transfer is studied as a function of t and of recoil mass MM 2 . Substantial agreement with the predictions of the additive quark model is found. The Σ + (1385) production in the target fragmentation region is studied in the framework of the triple-Regge model. (Auth.)

Nuclear Matrix Elements for the $\\beta\\beta$ Decay of the $^{76}$Ge

CERN Document Server

Brown, B A; Horoi, M

2015-01-01

The nuclear matrix elements for two-neutrino double-beta (2 n$\\beta\\beta$ ) and zero-neutrino double-beta (0 n$\\beta\\beta$) decay of 76 Ge are evaluated in terms of the configuration interaction (CI), quasiparticle random phase approximation (QRPA) and interacting boson model (IBM) methods. We show that the decomposition of the matrix elements in terms of interemediate states in 74 Ge is dominated by ground state of this nucleus. We consider corrections to the CI results that arise from configurations admixtures involving orbitals out-side of the CI configuration space by using results from QRPA, many-body-perturbation theory, and the connections to related observables. The CI two-neutrino matrix element is reduced due to the inclusion of spin-orbit partners, and to many-body correlations connected with Gamow-Teller beta decay. The CI zero-neutrino matrix element for the heavy neutrino is enhanced due to particle-particle correlations that are connected with the odd-even oscillations in the nuclear masse...

Characteristics and Modification of Non-metallic Inclusions in Titanium-Stabilized AISI 409 Ferritic Stainless Steel

Science.gov (United States)

Kruger, Dirk; Garbers-Craig, Andrie

2017-06-01

This study describes an investigation into the improvement of castability, final surface quality and formability of titanium-stabilized AISI 409 ferritic stainless steel on an industrial scale. Non-metallic inclusions found in this industrially produced stainless steel were first characterized using SEM-EDS analyses through the INCA-Steel software platform. Inclusions were found to consist of a MgO·Al2O3 spinel core, which acted as heterogeneous nucleation site for titanium solubility products. Plant-scale experiments were conducted to either prevent the formation of spinel, or to modify it by calcium treatment. Modification to spherical dual-phase spinel-liquid matrix inclusions was achieved with calcium addition, which eliminated submerged entry nozzle clogging for this grade. Complete modification to homogeneous liquid calcium aluminates was achieved at high levels of dissolved aluminum. A mechanism was suggested to explain the extent of modification achieved.

Wetting of refractory metals with copper base alloys

International Nuclear Information System (INIS)

Anikeev, E.F.; Kostikov, V.I.; Chepelenko, V.N.; Batov, V.M.

1978-01-01

The effect is studied of phosphorus upon the wetting of molybdenum, niobium and tantalum by an alloy of the system copper-silver (10%) as a function of contact time and phosphorus concentration. Experiments have been conducted in vacuum of 5x10 -4 mm Hg at 900 deg C. It is established that the introduction of phosphorus into a copper-silver alloy improves the wetting of molybdenum, niobium and tantalum. Formation of intermetallic compounds on the alloy-refractory metal interface can be avoided by adjusting the time of contact of the solder with molybdenum, niobium and tantalum. As a solder with 2.9% phosphorus spreads well over copper, it is suggested to use said solder for brazing copper and the investigated refractory metals in items intended for service at temperatures of up to 600 deg C

Extension of anisotropic effective medium theory to account for an arbitrary number of inclusion types

Science.gov (United States)

Myles, Timothy D.; Peracchio, Aldo A.; Chiu, Wilson K. S.

2015-01-01

The purpose of this work is to extend, to multi-components, a previously reported theory for calculating the effective conductivity of a two component mixture. The previously reported theory involved preferentially oriented spheroidal inclusions contained in a continuous matrix, with inclusions oriented relative to a principle axis. This approach was based on Bruggeman's unsymmetrical theory, and is extended to account for an arbitrary number of different inclusion types. The development begins from two well-known starting points; the Maxwell approach and the Maxwell-Garnett approach for dilute mixtures. It is shown that despite these two different starting points, the final Bruggeman type equation is the same. As a means of validating the developed expression, comparisons are made to several existing effective medium theories. It is shown that these existing theories coincide with the developed equations for the appropriate parameter set. Finally, a few example mixtures are considered to demonstrate the effect of multiple inclusions on the calculated effective property. Inclusion types of different conductivities, shapes, and orientations are considered and each of the aforementioned properties is shown to have a potentially significant impact on the calculated mixture property.

Refractory compounds for repairing coke-oven brickwork

Energy Technology Data Exchange (ETDEWEB)

Hanganu, M.; Dragomir, C. (and others)

1984-01-01

A number of refractory compounds are presented, based on aluminium phosphate, phosphoric acid, sodium silicate and fire-clay and mullitic zirconium mastic, including their composition, properties and application (by impregnation, spray application or pouring), which are suitable for repairing various types of coke-oven brickwork. The results obtained are given.

Topical application of amelogenin extracellular matrix protein in non-healing venous ulcers

Directory of Open Access Journals (Sweden)

Burçin Abud

2014-12-01

Full Text Available Background and Design: Treatment of chronic venous ulcers of the lower extremity is still an important difficulty. The principal treatment of these ulcers includes compression therapy, local wound care and surgery. Unresponsiveness to these standard treatments is a frequent situation with negative effects on life quality and reductions in personal productivity. Therefore, there is a need for new applications to increase the effectiveness of treatment in treatment-resistant cases. In the present study, we retrospectively evaluated the results of topical application of amelogenin extracellular matrix protein in resistant venous ulcers. Materials and Methods: We analyzed the records of patients with treatment-resistant venous ulceration who were treated with amelogenin extracellular matrix protein between June 2011 and December 2012.. Results: 26 patients (21 male and 5 female with a total number of 28 ulcers (24 patients with 1 ulcer, 2 patients with two ulcers were evaluated. The patients were treated with topically applied amelogenin extracellular matrix protein and regional four bandage compression. Bandages were changed weekly. Each cure continued for six weeks. In fourteen patients (15 ulcers, we observed a complete healing by the end of the first cure. In another twelve cases (13 ulcers, the same period resulted with a reduction in wound diameter. We continued to the second cure for these patients. By the end of the second cure, complete healing was achieved in five cases (6 ulcers. Conclusion: Topical application of amelogenin extracellular matrix protein may be considered as an effective therapeutic choice for refractory venous ulcers.

Treatment of refractory/relapsed adult acute lymphoblastic leukemia with bortezomib- based chemotherapy

Directory of Open Access Journals (Sweden)

Zhao J

2015-06-01

Full Text Available Junmei Zhao,* Chao Wang,* Yongping Song, Yuzhang Liu, Baijun FangHenan Key Lab of Experimental Haematology, Henan Institute of Haematology, Henan Tumor Hospital, Zhengzhou University, Zhengzhou, People’s Republic of China  *These authors contributed equally to this work Abstract: Nine pretreated patients aged >19 years with relapsed/refractory acute lymphoblastic leukemia (ALL were treated with a combination of bortezomib plus chemotherapy before allogeneic hematopoietic stem cell transplantation (allo-HSCT. Eight (88.9% patients, including two Philadelphia chromosome-positive ALL patients, achieved a complete remission. Furthermore, the evaluable patients have benefited from allo-HSCT after response to this reinduction treatment. We conclude that bortezomib-based chemotherapy was highly effective for adults with refractory/relapsed ALL before allo-HSCT. Therefore, this regimen deserves a larger series within prospective trials to confirm these results. Keywords: acute lymphoblastic leukemia, refractory, relapsed, bortezomib

Long-term effects of electrical neurostimulation in patients with unstable angina : Refractory to conventional therapies

NARCIS (Netherlands)

de Vries, Jessica; DeJongste, Mike J. L.; Zijlstra, Felix; Staal, Michiel

2007-01-01

Background. Patients with unstable angina pectoris may become refractory to conventional therapies. Electrical neurostimulation with transcutaneous electrical stimulation and/or spinal cord stimulation has been shown to be effective for patients with refractory unstable angina pectoris in hospital

Degradation of Alumina and Magnesia Chrome refractory bricks in Portland cement kiln – Corrected version*

Directory of Open Access Journals (Sweden)

Ben Addi K.

2014-05-01

Full Text Available In cement plants, the refractory products are particularly confronted to partially liquid oxide phases at temperature ranging between 900°C and 1700°C. All constituents of these products have to resist not only to thermal constraints, but also to the thermochemical solicitations which result from contact material/coating. In order to study the phenomenon of degradation of refractory bricks in cement kilns and to identify the causes of their degradation, we proceed to the examination of industrial cases in cement kiln. Many chemical tests of the degraded refractory bricks have been done and the results acquired were compared to the ones not used. The analysis of the results is doing using different techniques (Loss of ignition, X-ray Fluorescence, X-ray Diffraction. The results show that the degradation of the used bricks in the clinkering and cooling zone is due to the infiltration of aggressive elements such us sulphur, alkali (Na2O, K2O .... The chemical interaction between the Portland clinker phases and refractory material has also an importance on the stability of the coating and consequently on the life of the refractories.

Pembrolizumab and Vorinostat in Treating Patients With Relapsed or Refractory Diffuse Large B-Cell Lymphoma, Follicular Lymphoma, or Hodgkin Lymphoma

Science.gov (United States)

2018-04-23

Grade 3a Follicular Lymphoma; Grade 3b Follicular Lymphoma; Recurrent Classical Hodgkin Lymphoma; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Follicular Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Mediastinal (Thymic) Large B-Cell Cell Lymphoma; Refractory Classical Hodgkin Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Follicular Lymphoma; Refractory Mediastinal (Thymic) Large B-Cell Cell Lymphoma

Energy conservation in industrial furnaces with vertical radiation roofs of reinforced refractory concrete

Energy Technology Data Exchange (ETDEWEB)

Grafe, E

1981-01-01

The paper discusses static systems for furnaces of reinforced refractory concrete, the temperature field over the finned-plate cross section, the calculation of the reinforced refractory concrete, experimental application in a flat open-hearth pusher furnace, a pack heating furnace, and a sinker furnace. There are cantilever beam plates, frames, and drop ceiling elements particularly suited for efficient use of high-performance burners.

Two-Step Oxidation of Refractory Gold Concentrates with Different Microbial Communities.

Science.gov (United States)

Wang, Guo-Hua; Xie, Jian-Ping; Li, Shou-Peng; Guo, Yu-Jie; Pan, Ying; Wu, Haiyan; Liu, Xin-Xing

2016-11-28

Bio-oxidation is an effective technology for treatment of refractory gold concentrates. However, the unsatisfactory oxidation rate and long residence time, which cause a lower cyanide leaching rate and gold recovery, are key factors that restrict the application of traditional bio-oxidation technology. In this study, the oxidation rate of refractory gold concentrates and the adaption of microorganisms were analyzed to evaluate a newly developed two-step pretreatment process, which includes a high temperature chemical oxidation step and a subsequent bio-oxidation step. The oxidation rate and recovery rate of gold were improved significantly after the two-step process. The results showed that the highest oxidation rate of sulfide sulfur could reach to 99.01 % with an extreme thermophile microbial community when the pulp density was 5%. Accordingly, the recovery rate of gold was elevated to 92.51%. Meanwhile, the results revealed that moderate thermophiles performed better than acidophilic mesophiles and extreme thermophiles, whose oxidation rates declined drastically when the pulp density was increased to 10% and 15%. The oxidation rates of sulfide sulfur with moderate thermophiles were 93.94% and 65.73% when the pulp density was increased to 10% and 15%, respectively. All these results indicated that the two-step pretreatment increased the oxidation rate of refractory gold concentrates and is a potential technology to pretreat the refractory sample. Meanwhile, owing to the sensitivity of the microbial community under different pulp density levels, the optimization of microbial community in bio-oxidation is necessary in industry.

MgAl2O4 spinel refractory as containment liner for high-temperature alkali salt containing environments

Science.gov (United States)

Peascoe-Meisner, Roberta A [Knoxville, TN; Keiser, James R [Oak Ridge, TN; Hemric, James G [Knoxville, TN; Hubbard, Camden R [Oak Ridge, TN; Gorog, J Peter [Kent, WA; Gupta, Amul [Jamestown, NY

2008-10-21

A method includes containing a high-temperature alkali salt containing environment using a refractory containment liner containing MgAl.sub.2O.sub.4 spinel. A method, includes forming a refractory brick containing MgAl.sub.2O.sub.4 spinel having an exterior chill zone defined by substantially columnar crystallization and an interior zone defined by substantially equiaxed crystallization; and removing at least a portion of the exterior chill zone from the refractory brick containing MgAl.sub.2O.sub.4 spinel by scalping the refractory brick containing MgAl.sub.2O.sub.4 spinel to define at least one outer surface having an area of substantially equiaxed crystallization. A product of manufacture includes a refractory brick containing MgAl.sub.2O.sub.4 spinel including an interior zone defined by substantially equiaxed crystallization; and at least one outer surface having an area of substantially equiaxed crystallization.

Covered metal stent or multiple plastic stents for refractory pancreatic ductal strictures in chronic pancreatitis: a systematic review.

Science.gov (United States)

Shen, Yonghua; Liu, Mingdong; Chen, Min; Li, Yunhong; Lu, Ying; Zou, Xiaoping

2014-01-01

Refractory chronic pancreatitis has been proposed as a challenge for endoscopists following routine single plastic stenting. However, data on the efficacy and safety of further endoscopic stenting are still controversial. The current systematic review aimed to assess the efficacy and safety of placement of fully covered self-expandable metal stent (FCSEMS) and multiple plastic stents. Databases including MEDLINE, EMBASE, the Cochrane Library, CBM, CNKI, VIP, and WANFANG Database were used to search relevant trials. Published studies were assessed by using well-defined inclusion and exclusion criteria. The process was independently performed by two investigators. A total of 5 studies provided data of 80 patients. Forest plots and publication bias were not carried out because few studies were relevant and screened studies were all case series. The technical success rate was 100% both in placement of FCSEMS and multiple plastic stents. The functional success rate after placement of FCSEMS was 100%, followed by multiple plastic stents (94.7%). Complications occurred 26.2% after FCSEMS placement, which was not described in detail in multiple plastic stents. The stent migration rate was 8.2% for FCSEMS and 10.5% for multiple plastic stents. Reintervention rate was 9.8% for FCSEMS and 15.8% for multiple plastic stents. Pain improvement rate was 85.2% for FCSEMS and 84.2% for multiple plastic stents. FCSEMS appeared to be no significant difference with multiple plastic stents in treatment of refractory chronic pancreatitis. We need to develop more investigations. Copyright © 2014 IAP and EPC. Published by Elsevier B.V. All rights reserved.

Performance Evaluation of Refractory Composite Coatings in Potassium Rich Environment

Directory of Open Access Journals (Sweden)

Kristina BRINKIENĖ

2016-09-01

Full Text Available A laboratory scale method was used to study the performance of reinforced cement composites in potassium rich environment of biomass combustion. Buckwheat husk (BH was used as potential source of unexploited biomass product applicable as biomass derived fuel. In order to enhance the alkali effect on the properties of the investigated materials, the solution of potassium carbonate (K2CO3 was selected as potassium rich aggressive environment. Two reinforced cement composites as potential repair coatings for restoration of damaged refractory surfaces with different composition of aggregate were used in corrosion tests. Performance of refractory coatings was evaluated by analysing the microstructure of the treated composites as well as mechanical properties. Energy-dispersive X-ray spectroscopy (SEM/EDS and optical microscopy were used to study the microstructure in the corroded region of the refractory coatings. Long term studies in the solution of 1M K2CO3 for 56 months have demonstrated that composite with the additive of fluid cracking catalyst of oil refinery and petrochemical industries is more durable in the potassium rich environment.DOI: http://dx.doi.org/10.5755/j01.ms.22.3.8348

Corrosion assessment of refractory materials for high temperature waste vitrification

International Nuclear Information System (INIS)

Marra, J.C.; Congdon, J.W.; Kielpinski, A.L.

1995-01-01

A variety of vitrification technologies are being evaluated to immobilize radioactive and hazardous wastes following years of nuclear materials production throughout the Department of Energy (DOE) complex. The compositions and physical forms of these wastes are diverse ranging from inorganic sludges to organic liquids to heterogeneous debris. Melt and off-gas products can be very corrosive at the high temperatures required to melt many of these waste streams. Ensuring material durability is required to develop viable treatment processes. Corrosion testing of materials in some of the anticipated severe environments is an important aspect of the materials identification and selection process. Corrosion coupon tests on typical materials used in Joule heated melters were completed using glass compositions with high salt contents. The presence of chloride in the melts caused the most severe attack. In the metal alloys, oxidation was the predominant corrosion mechanism, while in the tested refractory material enhanced dissolution of the refractory into the glass was observed. Corrosion testing of numerous different refractory materials was performed in a plasma vitrification system using a surrogate heterogeneous debris waste. Extensive corrosion was observed in all tested materials

Treatment of refractory chylothorax with externalized pleuroperitoneal shunts in children.

Science.gov (United States)

Wolff, A B; Silen, M L; Kokoska, E R; Rodgers, B M

1999-09-01

Traditional therapy for refractory chylothorax in the pediatric population has included pleurodesis and thoracic duct ligation. These procedures are associated with high morbidity and questionable success rates. We retrospectively reviewed our experience with 15 patients who underwent treatment for chylous effusions using pleuroperitoneal shunts with exteriorized pump chambers. Mean patient age at time of shunt placement was 2.1 (0.1 to 11.5) years and the most common indication (7 of 15) was refractory chylothorax following surgical correction of congenital heart disease. Mean chylothorax duration before shunt placement was 76 (5 to 810) days and shunts were in place for an average of 104 (12 to 365) days. A total of 19 chylous effusions (pleural or pericardial) were treated with shunts. Nine of 11 right-sided chylothoraces, 5 of 6 left-sided chylothoraces, and 2 of 2 chylopericardia resolved with shunt therapy (84% total). Pleuroperitoneal shunting failed to clear the effusion in 3 children. There were six episodes of shunt malfunction that were repaired and two episodes of infection. Inguinal or umbilical hernia developed in 4 patients. Externalized pleuroperitoneal shunting is a safe, effective, and minimally invasive treatment for children with refractory chylous effusions.

CORRELATION OF 48Ca, 50Ti, AND 138La HETEROGENEITY IN THE ALLENDE REFRACTORY INCLUSIONS

International Nuclear Information System (INIS)

Chen, Hsin-Wei; Lee, Typhoon; Lee, Der-Chuen; Chen, Jiang-Chang

2015-01-01

Precise determinations of 48 Ca anomalies in Allende calcium–aluminum-rich inclusions (CAIs) are reported in this work. There are endemic positive 48 Ca/ 44 Ca anomalies in all analyzed CAIs after normalization to 42 Ca/ 44 Ca, and it is clearly shown that there is no simple correlation between 48 Ca/ 44 Ca and 50 Ti/ 48 Ti anomalies, in agreement with Jungck et al. Compared to the 48 Ca/ 44 Ca versus 50 Ti/ 48 Ti correlation line defined by differentiated meteorites, reported by Chen et al., the CAIs plot to elevated 50 Ti/ 48 Ti. Assuming the 48 Ca/ 44 Ca anomalies of both CAIs and differentiated meteorites came from the same source, excess 50 Ti anomalies in CAIs can be calculated by subtracting the part associated with 48 Ca/ 44 Ca. These excesses show a linear correlation with 138 La anomalies, a neutrino-process nuclide. According to current stellar nucleosynthetic models, we therefore suggest that the solar system 48 Ca, 50 Ti, and 138 La isotopic variations are made of mixtures between grains condensed from ejecta of neutron-rich accretion-induced SNe Ia and the O/Ne–O/C zone of core-collapse SNe II

Tocilizumab for refractory organising pneumonia associated with Sjögren's disease.

Science.gov (United States)

Justet, Aurelien; Ottaviani, Sebastien; Dieudé, Philippe; Taillé, Camille

2015-05-14

Lung involvement in primary Sjögren syndrome occurs in approximately 10-20% of patients. Tocilizumab, an anti-interleukin-6 receptor antibody, has demonstrated efficacy and safety in small series of systemic sclerosis, and systemic lupus erythematosus, but its effect on interstitial lung manifestations of connective tissue diseases is not well known. We report the use of tocilizumab in a refractory organising pneumonia associated with Sjögren's disease. Our observation suggests that tocilizumab could be an alternative therapeutic in refractory organising pneumonia. 2015 BMJ Publishing Group Ltd.

Epilepsy surgery and neurocysticercosis: Assessing the role of the cysticercotic lesion in medically-refractory epilepsy.

Science.gov (United States)

Escalaya, Alejandro L; Burneo, Jorge G

2017-11-01

There is increasing evidence of the existence of refractoriness to treatment with antiepileptic medications in those with NCC-related epilepsy. We performed a systematic review with the objective to determine the role of a cysticercotic lesion in this group of patients. We sought those manuscripts, including case reports, describing patients with NCC-related medically-intractable epilepsy who underwent epilepsy surgery and were seizure-free a year after. Only 10 manuscripts fulfilled inclusion and exclusion criteria. Three different clinical presentations were identified: 1) the cysticercotic lesion was epileptogenic, 2) there was dual pathology, including the cysticercotic lesion, with the other lesion usually being hippocampal sclerosis, and 3) the cysticercotic lesion was not related to the epileptogenic focus. In the case of an epileptogenic cysticercotic lesion, the presence of gliosis appeared to be the culprit for epileptogenicity. More studies using large cohorts of patients might be able to confirm our findings. This article is part of a Special issue entitled "Neurocysticercosis and Epilepsy". Copyright © 2017 Elsevier Inc. All rights reserved.

Influence of nanosized inclusions on the room temperature thermoelectrical properties of a p-type bismuth–tellurium–antimony alloy

International Nuclear Information System (INIS)

Bernard-Granger, Guillaume; Addad, Ahmed; Navone, Christelle; Soulier, Mathieu; Simon, Julia; Szkutnik, Pierre-David

2012-01-01

Transmission electron microscopy observations and thermoelectrical property measurements (electrical conductivity, Seebeck coefficient and thermal conductivity) at room temperature have been completed on two fully dense polycrystalline p-type bismuth–tellurium–antimony alloy samples. It is shown that the presence of antimony oxide-based nanosized inclusions (controlled as to volume fraction and size distribution), homogeneously dispersed in the surrounding matrix leads to a dimensionless figure of merit (ZT) of ∼1.3 at room temperature. For comparison, when such inclusions are missing the ZT value is only 0.6.

Rikkunshito improves globus sensation in patients with proton-pump inhibitor-refractory laryngopharyngeal reflux.

Science.gov (United States)

Tokashiki, Ryoji; Okamoto, Isaku; Funato, Nobutoshi; Suzuki, Mamoru

2013-08-21

To investigate the effect of rikkunshito on laryngopharyngeal reflux (LPR) symptoms and gastric emptying in patients with proton-pump inhibitor (PPI)-refractory LPR. In total, 22 patients with LPR were enrolled. Following a 2-wk treatment with PPI monotherapy, PPI-refractory LPR patients were randomly divided into two treatment groups (rikkunshito alone or rikkunshito plus the PPI, lansoprazole). LPR symptoms were assessed using a visual analog scale (VAS) score, gastrointestinal symptoms were assessed using the gastrointestinal symptom rating scale (GSRS), and gastric emptying was assessed using the radio-opaque marker method prior to and 4 wk following treatments. The 4-wk treatment with rikkunshito alone and with rikkunshito plus the PPI significantly decreased the globus sensation VAS scores. The VAS score for sore throat was significantly decreased following treatment with rikkunshito plus PPI but not by rikkunshito alone. Neither treatment significantly changed the GSRS scores. Rikkunshito improved delayed gastric emptying. We found a significant positive correlation between improvements in globus sensation and in gastric emptying (r² = 0.4582, P sensation in patients with PPI-refractory LPR, in part, because of stimulation of gastric emptying. Thus, rikkunshito is an effective treatment for PPI-refractory LPR.

Approaching Inclusion as Social Practice: Processes of Inclusion and Exclusion

DEFF Research Database (Denmark)

Molbæk, Mette; Hansen, Janne Hedegaard; Lassen, Mikkel

2018-01-01

The article presents the results of a review of international research investigating mechanisms and processes of inclusion and exclusion as an ongoing part of social practice in a school context. The review forms part of a research project investigating the social practices of inclusive education...... in primary and lower-secondary education (age 6–16) in public schools as constituted by processes of inclusion and exclusion. The project aims to shift the scientific focus of research in inclusive education from the development of pedagogical and didactic practice to the importance of community construction...... through inclusion and exclusion processes. The project arises in context of Danish education policy, while the review looked for international research findings on the limits between inclusion and exclusion: how they are drawn, by whom, for what reasons, and for whose benefit? On the background...

Alternative preparation of inclusion bodies excludes interfering non-protein contaminants and improves the yield of recombinant proinsulin.

Science.gov (United States)

Mackin, Robert B

2014-01-01

The goal of simple, high-yield expression and purification of recombinant human proinsulin has proven to be a considerable challenge. First, proinsulin forms inclusion bodies during bacterial expression. While this phenomenon can be exploited as a capture step, conventionally prepared inclusion bodies contain significant amounts of non-protein contaminants that interfere with subsequent chromatographic purification. Second, the proinsulin molecules within the inclusion bodies are incorrectly folded, and likely cross-linked to one another, making it difficult to quantify the amount of expressed proinsulin. Third, proinsulin is an intermediate between the initial product of ribosomal translation (preproinsulin) and the final product secreted by pancreatic beta cells (insulin). Therefore, to be efficiently produced in bacteria, it must be produced as an N-terminally extended fusion protein, which has to be converted to authentic proinsulin during the purification scheme. To address all three of these problems, while simultaneously streamlining the procedure and increasing the yield of recombinant proinsulin, we have made three substantive modifications to our previous method for producing proinsulin:.•Conditions for the preparation of inclusion bodies have been altered so contaminants that interfere with semi-preparative reversed-phase chromatography are excluded while the proinsulin fusion protein is retained at high yield.•Aliquots are taken following important steps in the procedure and the quantity of proinsulin-related polypeptide in the sample is compared to the amount present prior to that step.•Final purification is performed using a silica-based reversed-phase matrix in place of a polystyrene-divinylbenzene-based matrix.

[Nursing management of a refractory cardiac death donor].

Science.gov (United States)

Kaufmann, Marion

2016-09-01

The nursing management of a refractory circulatory death donor is a new procedure which forms an integral part of patient care. It comprises technical and organisational aspects, and requires a conceptual, ethical and deontological effort. Copyright © 2016. Published by Elsevier Masson SAS.

Limits to Inclusion

Science.gov (United States)

Hansen, Janne Hedegaard

2012-01-01

In this article, I will argue that a theoretical identification of the limit to inclusion is needed in the conceptual identification of inclusion. On the one hand, inclusion is formulated as a vision that is, in principle, limitless. On the other hand, there seems to be an agreement that inclusion has a limit in the pedagogical practice. However,…

Pulsed radiofrequency of brachial plexus under ultrasound guidance for refractory stump pain: a case report

Directory of Open Access Journals (Sweden)

Zheng B

2017-11-01

Full Text Available Bixin Zheng, Li Song, Hui Liu Department of Pain Management, West China Hospital of Sichuan University, Chengdu, China Abstract: The post-amputation (pain syndrome, including stump pain, phantom limb sensation, and phantom limb pain is common but difficult to treat. Refractory stump pain in the syndrome is an extremely challenging and troublesome clinical condition. Patients respond poorly to drugs, nerve blocks, and other effective treatments like spinal cord stimulation and surgery. Pulsed radiofrequency (PRF technique has been shown to be effective in reducing neuropathic pain. This report describes a patient with persistent and refractory upper limb stump pain being successfully relieved with PRF of brachial plexus under ultrasound guidance after a 6-month follow-up period, suggesting that PRF may be considered as an alternative treatment for refractory stump-neuroma pain. Keywords: ultrasound guidance, pulsed radiofrequency, brachial plexus, refractory stump pain 

Development of industrial x-ray computed tomography and its application to refractories

International Nuclear Information System (INIS)

Aiba, Yoshiro; Oki, Kazuo; Nakamura, Shigeo; Fujii, Masashi.

1985-01-01

An industrial X-ray computed tomography was developed under the influence of the rapid spread of the use of the X-ray CT scanner in the medical field and improvements of the equipment. Although current nondestructive testing machines of refractories use the ultrasonic inspection method or the X-ray fluoroscopic method, these equipments cannot produce a tomogram or cannot carry out quantitative evaluation. By using an industrial X-ray computed tomography, submerged nozzles for continuous casting of steel were analyzed with interesting results. The features of the industrial X-ray computed tomography applied for refractory nozzles are as follows: (1) It promptly detects interior defects. (2) It can measure dimensions and shapes. (3) It can numerically express the distribution of density. Accordingly, it is expected that the industrial X-ray computed tomography will widely be used in the fields of development and quality control of refractories and advanced ceramic materials. (author)

Optimization of the Technological Synthesis of Refractory Compounds

Science.gov (United States)

Gaidar, S. M.; Karelina, M. Yu.; Prikhod'ko, V. M.; Volkov, A. A.

2017-12-01

The results of experimental studies, which are related to the regulation of the fractional composition of refractory compounds by roll milling in using controlled roll opening and unbalanced peripheral speeds of rollers, are reported. The content of prepared fine, middle, and coarse fractions is within 50-80%; in this case, the milling time of synthesis products is less than the time of ball milling by an order of magnitude. The application of roll milling for refining the products of self-propagating high-temperature synthesis can be most efficient in using together with heat-generating reactor to solve the main problem of self-propagating synthesis (SHS), which is a problem for recent several decades (the problem is the creation of intense automated production of refractory compounds in using continuous manufacturing cycle within a energotechnological system with the recovery of a great quantity of heat released during SHS).

Diode and Nd:YAG laser in a case of refractory acne keloidalis nuchae

Directory of Open Access Journals (Sweden)

Ravi Kumar Chittoria

2015-03-01

Full Text Available Acne keloidalis nuchae (AKN is a disease of unclear etiology that mainly affects males. Medical treatment of AKN is difficult, with refractory cases often requiring ablation by laser or surgical resection. We report herein, a 23-year-old male with refractory AKN treated successfully with combined laser ablation, using an 810-nm diode laser and a 1064-nm Nd:YAG laser.

Outcomes of Ahmed valve surgery for refractory glaucoma in Dhahran, Saudi Arabia

Directory of Open Access Journals (Sweden)

Tariq Alasbali

2015-06-01

Full Text Available AIM:To evaluate the outcomes of Ahmed glaucoma valve (AGV implantation surgery for refractory glaucoma.METHODS:This one-armed historical cohort study was conducted in 2011. Refractory glaucoma was defined as eyes with an intraocular pressure (IOP greater than 21 mm Hg with maximally tolerated glaucoma medications, failed surgeries, or both. For all eyes with refractory glaucoma that underwent AGV implantation, data were collected on IOP, the best corrected visual acuity (BCVA and glaucoma medications preoperatively and 4, 6, 12, 24 and 56wk postoperatively. Logarithm values of IOP were calculated and compared.RESULTS: The study group was comprised of 30 patients (30 eyes, 16 males and 14 females with refractory glaucoma. Mean preoperative IOP was 39.3±13.8 mm Hg. Postoperative mean IOP was 15.7±7.1 mm Hg, 19.6±12.8 mm Hg and 13.9±14.2 mm Hg at 12, 24 and 56wk respectively. BCVA was ≥ 6/60 in 11 eyes preoperatively, and five eyes had BCVA≥6/60 at 56wk postoperatively. Preoperatively, more than four medications were used to treat glaucoma in 21 eyes. At 12wk postoperatively, no medications were required to control IOP in 20 eyes. At 56wk postoperatively, at least one medication was required to control IOP in 10 eyes. Over the entire follow up period, four eyes were treated with yttrium aluminium garnet (YAG laser and 14 eyes required a second surgery. The AGV was removed in four eyes.CONCLUSION: AGV implantation reduced IOP and the number of medications required to control refractory glaucoma. However, there was a higher risk of decreased vision. Long-term follow up and prompt intervention are recommended.

Determination of the resistance to tensile fracture of refractory mixtures of gunite

International Nuclear Information System (INIS)

Gomez Sanchez, A; Tomba Martinez, A.G

2004-01-01

The determination of the mechanical properties of cooled refractory mixtures is useful since it allows the materials to be compared for the purposes of selection and reports on their degree of internal cohesion, green or calcination, so that their structural ability can be estimated, especially during installation. Given the testing difficulties originating in the fragility of the ceramic materials, the tension test is not generally used in refractories. However, ASTM C-307 94 determines the tensile strength of cured chemical-resistant materials, for which this work considered the possibility of testing cement-based monolithic refractories in this non conventional condition. The tensile resistance to the fracture of three different refractory mixtures (A, B 1 and B 2 ), used in heat repairing by gunite in coking ovens, that were characterized by chemical, granulometric, and mineralogical analysis pycnometric density measurements. The pieces for the tests ('bone' type: length = 75 mm, maximum width = 40 mm, minimum width = 25 mm, thickness = 10 - 25 mm) were prepared by ramming of mixtures of material/water in a metallic mold; they were sinterized (1200 o C, 1h) and characterized by measures of bulk density, porosity and observation of the surface texture, in green and calcinated. The tensile tests, based on ASTM C-307 94, were performed in an Instron model 4467 machine in open air, at room temperature and position control (0.5 mm/min). The following values were obtained, in kPa: AW347±308; B 1 W738±130; B 2 W604±64. These values were lower than those for the tensile fracture module (MOR), although they displayed an equivalent order: A≤B 2 ≤B 1 . This was related to the characteristics of each refractory mixture and at the end of the pieces tested (CW)

An unusual case of refractory wheeze

OpenAIRE

Ramesh, Venkat; Acharya, Vishak; Pai, Narasimha; Krishnan, Ananda

2015-01-01

A 37-year-old man presented with a history of episodic wheeze and breathlessness of 3?years? duration refractory to treatment. Physical examination revealed diffuse expiratory polyphonic rhonchi while the remainder of the examination including the cardiac examination was reported as normal. Pulmonary function testing revealed mild obstruction with bronchodilator reversibility. The patient was discharged on a 6-month course of antitubercular treatment (ATT) as bronchial brush cytology (obtaine...

Supra-Tenon Capsule Implantation of the Ahmed Glaucoma Valve in Refractory Pediatric Glaucoma.

Science.gov (United States)

Elhefney, Eman M; Al-Sharkawy, Hossam T; Kishk, Hanem M

2016-09-01

To evaluate the efficacy of supra-Tenon capsule implantation of an Ahmed glaucoma valve (AGV) as a measure to decrease the fibrotic potential of the Tenon capsule on bleb formation and its subsequent effect on intraocular pressure (IOP) control in children with refractory glaucoma. Mansoura Ophthalmic Centre, Faculty of Medicine, Mansoura University, Egypt. A prospective interventional study. Twenty-two eyes of 12 children with refractory glaucoma underwent supra-Tenon capsule implantation of AGV. Ophthalmic examinations under general anesthesia including measurement of the corneal diameter and the IOP with Perkin's tonometer were performed preoperatively, on the first postoperative day, the first postoperative week, weekly for the first month, 2-weekly for the following 3 months, and monthly for at least 18 months. Postoperative complications and the number of glaucoma medications used preoperatively and postoperatively were recorded. The paired Student t test was used to compare preoperative and postoperative data. There were 12 eyes (54.6%) with refractory congenital glaucoma, 7 eyes (31.8%) with refractory pseudophakic glaucoma, and 3 eyes (13.6%) with refractory aphakic glaucoma. Patients included 10 male (83.3%) and 2 female (16.7%) children with a mean age of 16.3±9.7 months. The mean follow-up duration was 24.1±4.3 months. There was a statistically significant difference between the mean preoperative IOP (30.7±2.88 mm Hg) and the mean postoperative IOP (16.1±3.60 mm Hg) (t=16.22 and P=0.000, with a mean decrease in the IOP by 47.6%). The difference between the mean number of antiglaucoma medications before surgery (1.86±0.4) and after surgery (1.0±0.9) was also statistically significant (t=4.31 and P=0.000). Total success was achieved in 18 eyes (81.9%). Postoperative complications included tube exposure and slippage (10%), hypotony (10%), and hyphema (5%). Supra-Tenon capsule implantation of the AGV was successful in controlling the IOP with few

Inclusive Business - What It Is All About? Managing Inclusive Companies

Directory of Open Access Journals (Sweden)

Tea Golja

2012-01-01

Full Text Available Following the challenges we face today, the inclusive business models are future business models through which the Millennium Development Goals can be fostered and strengthen. These are the models which, through their strategic orientation on inclusivity, include low income communities in their value chain. This can be done through combining variety of strategies which all have two common points – recognition of stakeholders and adjustment of the product to the target market. The paper presents the analysis of inclusive markets. Hence, the research results show the dispersion of inclusive businesses worldwide, type of the organization, sector coverage, and contribution to MDGs as well as the particular way of inclusion of low income communities in their value chain. The aim is to present how inclusive business benefits not only the low income societies, but the companies that operate in this way as well.

Refractory chronic migraine

DEFF Research Database (Denmark)

Martelletti, Paolo; Katsarava, Zaza; Lampl, Christian

2014-01-01

The debate on the clinical definition of refractory Chronic Migraine (rCM) is still far to be concluded. The importance to create a clinical framing of these rCM patients resides in the complete disability they show, in the high risk of serious adverse events from acute and preventative drugs...... and in the uncontrolled application of therapeutic techniques not yet validated.The European Headache Federation Expert Group on rCM presents hereby the updated definition criteria for this harmful subset of headache disorders. This attempt wants to be the first impulse towards the correct identification...... of these patients, the correct application of innovative therapeutic techniques and lastly aim to be acknowledged as clinical entity in the next definitive version of the International Classification of Headache Disorders 3 (ICHD-3 beta)....

Inclusion Characteristics and Acicular Ferrite Nucleation in Ti-Containing Weld Metals of X80 Pipeline Steel

Science.gov (United States)

Wang, Bingxin; Liu, Xianghua; Wang, Guodong

2018-06-01

X80 steel weld metals with Ti contents of 0.003 to 0.13 pct were prepared by the single-pass submerged-arc welding process. The effects of Ti content in weld metals on the constituent phases of inclusions and chemical compositions of the constituent phases, as well as the potency of acicular ferrite (AF) nucleation on the inclusions were investigated. Moreover, the crystallographic orientation relationship between the AF and inclusion was examined. The results show that with an increase in Ti content, the primary constituent phases of the inclusions change from the (Mn-Al-Si-O) compound to a mixture of spinel and pseudobrookite solid solutions, and eventually to pseudobrookite. The spinel solid solution is characterized by the MnTi2O4 constituent. Compared to pseudobrookite, spinel has a lower Ti concentration, but a significantly higher Mn content. In the case of the presence of a considerable amount of spinel, the Mn element is enriched strongly in the inclusions, resulting in the development of a Mn-depleted zone (MDZ) in the matrix around the inclusions, which enhances the driving force for AF formation. AF shows the Baker-Nutting orientation relationship with MnTi2O4. The formation of MDZ and the presence of the Baker-Nutting orientation relationship promote the ability of inclusions to nucleate the intragranular AF.

Influence of phase transformations on the mechanical behaviour of refractory ceramics at high temperature

International Nuclear Information System (INIS)

Schmitt, N.; Poirier, J.

2009-01-01

Refractories used at high temperature are subjected to high chemical and mechanical stresses. The mastery of their microstructure as well as the phase changes occurring in service is essential to ensure resistance to wear and failure of refractory linings. Great progress has been made: combining efficient techniques for the investigation of the microstructure with powerful numerical tools (thermochemical and thermo-mechanical computations) provides information (e.g., degradation mechanisms) that cannot be obtained directly. Also multi-physical and multi-scale models developing materials with high-performance for higher temperature and with longer lifetime. In this paper, through several examples we show some interactions between the mechanical behavior and the microstructure transformations of refractory ceramics. The tools developed to characterize their microstructure change in situ (e.g., at high temperature) and to identify their kinetics are described. Some methodologies and tools developed in recent years, today, provide a better understanding of in-service behavior of refractories while identifying the critical material and process parameters likely to increase life-time. (authors)

Primary pulmonary lymphoma mimicking a refractory lung abscess: A case report.

Science.gov (United States)

Matsumoto, Takeshi; Otsuka, Kojiro; Funayama, Yuki; Imai, Yukihiro; Tomii, Keisuke

2015-04-01

The current study presents a case of primary pulmonary lymphoma (PPL) mimicking refractory lung abscess that was diagnosed at autopsy. An 80-year-old male with clinically inapparent aspiration presented with a large cavitated mass and pleural effusion. A lung abscess and empyema was diagnosed, therefore, antibiotics were administered and the pleural effusion was drained. Various examinations, including a biopsy, yielded no specific diagnosis. The lesion was considered inoperable due to the poor general condition of the patient. Subsequently, the mass that had been diagnosed as a refractory lung abscess became enlarged and a repeat biopsy resulted in a diagnosis of diffuse large B-cell lymphoma. The patient succumbed to sudden respiratory failure, and the final diagnosis of PPL was confirmed at autopsy. PPL is a rare disease that accounts for 0.45% of all pulmonary malignant tumors and is difficult to diagnose in inoperable cases. Therefore, patients with PPL who do not undergo surgery can be misdiagnosed and consequently treated inappropriately. PPL should therefore be considered in the differential diagnosis of a refractory lung abscess.

Designing Inclusive Systems Designing Inclusion for Real-world Applications

CERN Document Server

Clarkson, John; Robinson, Peter; Lazar, Jonathan; Heylighen, Ann

2012-01-01

The Cambridge Workshops on Universal Access and Assistive Technology (CWUAAT) are a series of workshops held at a Cambridge University College every two years. The workshop theme: “Designing inclusion for real-world applications” refers to the emerging potential and relevance of the latest generations of inclusive design thinking, tools, techniques, and data, to mainstream project applications such as healthcare and the design of working environments. Inclusive Design Research involves developing tools and guidance enabling product designers to design for the widest possible population, for a given range of capabilities. There are five main themes: •Designing for the Real-World •Measuring Demand And Capabilities •Designing Cognitive Interaction with Emerging Technologies •Design for Inclusion •Designing Inclusive Architecture In the tradition of CWUAAT, we have solicited and accepted contributions over a wide range of topics, both within individual themes and also across the workshop’s scope. ...

Benefit–risk assessment of golimumab in the treatment of refractory ulcerative colitis

Directory of Open Access Journals (Sweden)

Pugliese D

2016-02-01

Full Text Available Daniela Pugliese, Carla Felice, Rosario Landi, Alfredo Papa, Luisa Guidi, Alessandro Armuzzi Inflammatory Bowel Disease Unit, Complesso Integrato Columbus, Catholic University, Rome, Italy Abstract: Significant advances in the management of patients with ulcerative colitis (UC have been made since the introduction of anti-tumor necrosis factor (TNF-alpha agents, especially for those who fail or do not tolerate conventional therapies. Two drugs, infliximab first, then adalimumab afterward, showed effectiveness in inducing and maintaining long-term remission both in pivotal trials as well as in clinical practice. However, approximately 25% of patients with UC, who fail or do not tolerate all available therapies, require a colectomy for refractory disease. The therapeutic scenario of UC has been recently upgraded by the introduction of golimumab, the latest anti TNF-alpha agent to be approved. Golimumab is a totally humanized monoclonal antibody, administered by a subcutaneous injection every 4 weeks. Treatment with golimumab has shown to be effective to induce sustained clinical benefit in tough-to-treat patients with UC, including steroid and/or immunosuppressive refractory and steroid-dependent patients. In this review, we summarize all available efficacy and safety data of golimumab in UC, analyzing the potential therapeutic position for the treatment of refractory patients with UC. Keywords: ulcerative colitis, refractoriness, anti-TNF-alpha, golimumab 

Anaesthesia for left thoracoscopic sympathectomy for refractory long ...

African Journals Online (AJOL)

... mutations including life-threatening cardiac arrhythmias and sudden death. Left thoracoscopic sympathectomy is an effective treatment for patients who are refractory to medical therapy or who need frequent epicardial internal cardio defibrillator intervention. The authors report three cases, one adult and two children, who ...

Unusual cause of respiratory distress misdiagnosed as refractory asthma

Directory of Open Access Journals (Sweden)

Al-Otair Hadil

2006-01-01

Full Text Available We report a young lady, who was labeled as a case of refractory asthma for a few years, based on history of shortness of breath on minimal exertion, noisy breathing and normal chest radiograph. Repeated upper airway exam by an otolaryngologist and computerized tomography scan, were normal. On presentation to our hospital, she was diagnosed to have fixed upper airway obstruction, based on classical flow-volume loop findings. Fibroptic bronchoscopy revealed a web-shaped subglottic stenosis. The histopathology of a biopsy taken from that area, showed non-specific inflammation. No cause for this stenosis could be identified. The patient was managed with rigid bronchoscopy dilatation, without recurrence. We report this case as idiopathic subglottic stenosis, that was misdiagnosed as refractory bronchial asthma, stressing the importance of performing spirometry in the clinic.

Percutaneous radiofrequency treatment for refractory anteromedial pain of osteoarthritic knees.

Science.gov (United States)

Ikeuchi, Masahiko; Ushida, Takahiro; Izumi, Masashi; Tani, Toshikazu

2011-04-01

Although severe knee osteoarthritis with refractory pain is commonly treated surgically, this is often not an option for patients with poor health status or unwillingness to undergo major surgery. We examined the efficacy of radiofrequency application to sensory nerves as a novel alternative treatment for refractory knee pain. This study was an open-label, nonrandomized, and controlled study. Patients complaining of refractory anteromedial knee pain associated with radiological osteoarthritis (moderate or severe) were included. They were assigned to one of two groups: those receiving radiofrequency thermocoagulation (N = 18) or those receiving nerve block (N = 17), depending on the time period that they were referred to the clinic. Radiofrequency current or local anesthetics was applied to the medial retinacular nerve and the infrapatellar branch of the saphenous nerve. Western Ontario McMaster Universities osteoarthritis index score, pain visual analog scale (VAS), and patient's global assessment were assessed with a minimum follow-up of 6 months.   Radiofrequency treatment significantly decreased knee pain as measured by VAS for 12 weeks compared with the control group. In terms of responders, more patients in the RF group responded to the treatment than in the control group. The differences were statistically significant at 4 weeks, 8 weeks, and 12 weeks in pain VAS. Eight patients (44%) treated with radiofrequency rated excellent or good but only three (18%) in the control group rated good, although the difference was not statistically significant. Some patients were able to benefit substantially from radiofrequency treatment. Even if its effective period is limited, radiofrequency application is a promising treatment to alleviate refractory anteromedial knee pain with osteoarthritis. Further experience and technical improvements are needed to establish its role in the management of knee osteoarthritis. Wiley Periodicals, Inc.

Pembrolizumab in Treating Younger Patients With Recurrent, Progressive, or Refractory High-Grade Gliomas, Diffuse Intrinsic Pontine Gliomas, Hypermutated Brain Tumors, Ependymoma or Medulloblastoma

Science.gov (United States)

2018-06-18

Constitutional Mismatch Repair Deficiency Syndrome; Lynch Syndrome; Malignant Glioma; Progressive Ependymoma; Progressive Medulloblastoma; Recurrent Brain Neoplasm; Recurrent Childhood Ependymoma; Recurrent Diffuse Intrinsic Pontine Glioma; Recurrent Medulloblastoma; Refractory Brain Neoplasm; Refractory Diffuse Intrinsic Pontine Glioma; Refractory Ependymoma; Refractory Medulloblastoma

Handbook of industrial refractories technology principles, types, properties and applications

CERN Document Server

Caniglia, Stephen

1989-01-01

Encompasses the entire range of industrial refractory materials and forms: properties and their measurement, applications, manufacturing, installation and maintenance techniques, quality assurance, and statistical process control.

Chondritic Meteorites: Nebular and Parent-Body Formation Processes

Science.gov (United States)

Rubin, Alan E.; Lindstrom, David (Technical Monitor)

2002-01-01

It is important to identify features in chondrites that formed as a result of parent-body modification in order to disentangle nebular and asteroidal processes. However, this task is difficult because unmetamorphosed chondritic meteorites are mixtures of diverse components including various types of chondrules, chondrule fragments, refractory and mafic inclusions, metal-sulfide grains and fine-grained matrix material. Shocked chondrites can contain melt pockets, silicate-darkened material, metal veins, silicate melt veins, and impact-melt-rock clasts. This grant paid for several studies that went far in helping to distinguish primitive nebular features from those produced during asteroidal modification processes.

The ketogenic diet in two paediatric patients with refractory myoclonic status epilepticus.

Science.gov (United States)

Caraballo, Roberto Horacio; Valenzuela, Gabriela Reyes; Armeno, Marisa; Fortini, Sebastian; Mestre, Graciela; Cresta, Araceli

2015-12-01

We describe two patients with refractory myoclonic status epilepticus treated with the ketogenic diet. Between May 1, 2014 and January 1, 2015, two patients who met the diagnostic criteria for refractory myoclonic status epilepticus, seen at our department, were placed on the ketogenic diet and followed for a minimum of six months. One patient with myoclonic epilepsy of unknown aetiology had a 75-90% seizure reduction, and the other with progressive encephalopathy associated with myoclonic epilepsy had a 50% seizure reduction. Both patients retained good tolerability for the diet. At the last control, one patient had isolated myoclonias and EEG showed occasional generalized spike-and-polyspike waves; the patient is now successfully attending kindergarten. The quality of life of the second patient improved significantly. In both cases, the number of antiepileptic drugs was reduced. The ketogenic diet is an effective and well-tolerated treatment option for patients with refractory myoclonic status epilepticus and should be considered earlier in the course of treatment.

Refractory experience in circulating fluidized bed combustors, Task 7. Final report

Energy Technology Data Exchange (ETDEWEB)

Vincent, R.Q.

1989-11-01

This report describes the results of an investigation into the status of the design and selection of refractory materials for coal-fueled circulating fluidized-bed combustors. The survey concentrated on operating units in the United States manufactured by six different boiler vendors: Babcock and Wilcox, Combustion Engineering, Foster Wheeler, Keeler Dorr-Oliver, Pyropower, and Riley Stoker. Information was obtained from the boiler vendors, refractory suppliers and installers, and the owners/operators of over forty units. This work is in support of DOE`s Clean Coal Technology program, which includes circulating fluidized-bed technology as one of the selected concepts being evaluated.

Intraarticular Pulsed Radiofrequency to Treat Refractory Lumbar Facet Joint Pain in Patients with Low Back Pain.

Science.gov (United States)

Chang, Min Cheol; Cho, Yun-Woo; Ahn, Da Hyun; Do, Kyung Hee

2018-04-01

Many treatment techniques have been used for refractory lumbar facet joint pain; however, their efficacy has been controversial. In this study, we investigated the clinical efficacy and safety of intra-articular pulsed radiofrequency for the treatment of refractory lumbar facet joint pain in patients with low back pain. Twenty patients with refractory lumbar facet joint pain were recruited, and each patient was treated via intra-articular pulsed radiofrequency. The treatment effects were measured with a numerical rating scale, and the technical accuracy of intra-articular pulsed radiofrequency treatment was evaluated independently by 2 radiologists. Any adverse events or complications also were checked. We performed intra-articular pulsed radiofrequency treatment at 48 levels of the lumbar facet joints in 20 patients (5 men and 15 women; mean age, 64.50 ± 10.65 years) with refractory lumbar facet joint pain. Pain scores were significantly reduced at 1 month, 3 months, and 6 months after treatment (P radiofrequency results in all 20 patients, without any serious adverse effects. Treatment using intra-articular pulsed radiofrequency is an alternative to other techniques in patients with refractory lumbar facet joint pain. Copyright © 2018 Elsevier Inc. All rights reserved.

Analysis of a multi-frequency electromagnetic imaging functional for thin, crack-like electromagnetic inclusions

OpenAIRE

Park, Won-Kwang

2012-01-01

Recently, a non-iterative multi-frequency subspace migration imaging algorithm was developed based on an asymptotic expansion formula for thin, curve-like electromagnetic inclusions and the structure of singular vectors in the Multi-Static Response (MSR) matrix. The present study examines the structure of subspace migration imaging functional and proposes an improved imaging functional weighted by the frequency. We identify the relationship between the imaging functional and Bessel functions ...

Processing of Refractory Metal Alloys for JOYO Irradiations

International Nuclear Information System (INIS)

RF Luther; ME Petrichek

2006-01-01

This is a summary of the refractory metal processing experienced by candidate Prometheus materiats as they were fabricated into specimens destined for testing within the JOYO test reactor, ex-reactor testing at Oak Ridge National Laboratory (ORNL), or testing within the NRPCT. The processing is described for each alloy from the point of inception to the point where processing was terminated due to the cancellation of Naval Reactor's involvement in the Prometheus Project. The alloys included three tantalum-base alloys (T-111, Ta-10W, and ASTAR-811C), a niobium-base alloy, (FS-85), and two molybdenum-rhenium alloys, one containing 44.5 w/o rhenium, and the other 47.5 w/o rhenium. Each of these alloys was either a primary candidate or back-up candidate for cladding and structural applications within the space reactor. Their production was intended to serve as a forerunner for large scale production ingots that were to be procured from commercial refractory metal vendors such as Wah Chang

Determination of Unit Pressure Force in Material Volume in the Course of Refractory Stamping Press Moulding

Directory of Open Access Journals (Sweden)

Orłowicz A.W.

2016-06-01

Full Text Available The paper presents results of assessment of the unit pressure force within the refractory material volume in the course press-moulding of stampings for refractory precast shapes. The force was evaluated with the use of physical simulation of deformation undergone by lead balls placed in the raw refractory mass subjected to pressing in a metal die. To determine the value of unit pressure force applied to the aggregate grains in the course of stamping press-moulding, physical model of deformation of a sphere induced by the uniaxial stress state was used.

Normal and refractory concretes for LMFBR applications. Volume 1. Review of literature on high-temperature behavior of portland cement and refractory concretes. Final report

International Nuclear Information System (INIS)

Bazant, Z.P.; Chern, J.C.; Abrams, M.S.; Gillen, M.P.

1982-06-01

The extensive literature on the properties and behavior at elevated temperature of portland cement concrete and various refractory concretes was reviewed to collect in concise form the physical and chemical properties of castable refractory concretes and of conventional portland cement concretes at elevated temperature. This survey, together with an extensive bibliography of source documents, is presented in Volume 1. A comparison was made of these properties, the relative advantages of the various concretes was evaluated for possible liquid metal fast breeder reactor applications, and a selection was made of several materials of interest for such applications. Volume 2 concludes with a summary of additional knowledge needed to support such uses of these materials together with recommendations on research to provide that knowledge

Use of refractory chromites for obtaining fluxes amassed employed in submerged arc welding (SAW); Empleo de cromitas refractarias par la obtencion de fundentes aglomerados utilizados en la soldadura automatica por arco sumegido (SAW)

Energy Technology Data Exchange (ETDEWEB)

Perdomo-Gonzalez, L.; Quintana-Puchol, R.; Cruz-Crespo, A.; Castellanos-Estupinan, J.; Garcia-Sanchez, L. L.; Formoso-Prego, A.; Cores-Sanchez, A.

2003-07-01

In the present work high carbon ferrochrome (load ferrochrome) and slags are obtained, starting from the metallurgic reductive processing of refractory chromites. The obtaining of alloys and slags is studied using an experiment design based in the relationships among components. The chemical compositions of alloys and slags guarantee their application for the conformation of alloys loads and matrix fluxes amassed for the superficial filling by means of submerged arc welding (SAW). The melting-reduction process is carried out in an electric arc furnace. (Author) 16 refs.

Thermal gradient brine inclusion migration in salt study: gas-liquid inclusions, preliminary model

International Nuclear Information System (INIS)

Olander, D.R.; Machiels, A.J.

1979-10-01

Natural salt deposits contain small cubical inclusions of brine distributed through the salt. Temperature gradients, resulting from storing heat-generating wastes in the salt, can cause the inclusions to move through the salt. Prediction of the rate and amount of brine-inclusion migration is necessary for the evaluation of bedded or domed salts as possible media for waste repositories. Inclusions filled exclusively with liquid migrate up the temperature gradient towards the heat source. The solubility of salt in the brine inclusion increases with temperature. Consequently, salt dissolves into the inclusion across the hot surface and crystallizes out at the cold surface. Diffusion of salt within the liquid phase from the hot to the cold faces causes the inclusions to move in the opposite direction. In so doing, they change shape and eventually become rectangular parallelipipeds with a width (dimension perpendicular to the thermal gradient) much larger than the thickness (dimension in the direction of the thermal gradient). The inclusions may also contain a gas phase predominantly consisting of water vapor. These entities are termed two-phase or gas-liquid inclusions. The two-phase inclusions usually migrate down the temperature gradient away from the heat source remaining more-or-less cubical. A two-phase inclusion also forms when an all-liquid inclusion reaches the waste package; upon opening up at the salt-package interface, the brine partially evaporates and the inclusion reseals with some insoluble gas trapped inside. These gas-liquid inclusions proceed to move down the temperature gradient, in the opposite sense of the all-liquid inclusions. The gas-liquid inclusions phenomenon provides a pathway by which radionuclides leached from the wasteform by the brine can be transported away from the waste package and thus might have greater access to the biosphere

Strategy BMT Al-Ittihad Using Matrix IE, Matrix SWOT 8K, Matrix SPACE and Matrix TWOS

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Nofrizal Nofrizal

2018-03-01

Full Text Available This research aims to formulate and select BMT Al-Ittihad Rumbai strategy to face the changing of business environment both from internal environment such as organization resources, finance, member and external business such as competitor, economy, politics and others. This research method used Analysis of EFAS, IFAS, IE Matrix, SWOT-8K Matrix, SPACE Matrix and TWOS Matrix. our hope from this research it can assist BMT Al-Ittihad in formulating and selecting strategies for the sustainability of BMT Al-Ittihad in the future. The sample in this research is using purposive sampling technique that is the manager and leader of BMT Al-IttihadRumbaiPekanbaru. The result of this research shows that the position of BMT Al-Ittihad using IE Matrix, SWOT-8K Matrix and SPACE Matrix is in growth position, stabilization and aggressive. The choice of strategy after using TWOS Matrix is market penetration, market development, vertical integration, horizontal integration, and stabilization (careful.

Developing a matrix to identify and prioritise research recommendations in HIV Prevention

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Coates Bob

2011-05-01

Full Text Available Abstract Background HIV prevention continues to be problematic in the UK, as it does globally. The UK Department of Health has a strategic direction with greater focus on prevention as part of its World Class Commissioning Programme. There is a need for targeted evidence-based prevention initiatives. This is an exploratory study to develop an evidence mapping tool in the form of a matrix: this will be used to identify important gaps in contemporary HIV prevention evidence relevant to the UK. It has the potential to aid prioritisation in future research. Methods Categories for prevention and risk groups were developed for HIV prevention in consultation with external experts. These were used as axes on a matrix tool to map evidence. Systematic searches for publications on HIV prevention were undertaken using electronic databases for primary and secondary research undertaken mainly in UK, USA, Canada, Australia and New Zealand, 2006-9. Each publication was screened for inclusion then coded. The risk groups and prevention areas in each paper were counted: several publications addressed multiple risk groups. The counts were exported to the matrix and clearly illustrate the concentrations and gaps of literature in HIV prevention. Results 716 systematic reviews, randomised control trials and other primary research met the inclusion criteria for HIV prevention. The matrix identified several under researched areas in HIV prevention. Conclusions This is the first categorisation system for HIV prevention and the matrix is a novel tool for evidence mapping. Some important yet under-researched areas have been identified in HIV prevention evidence: identifying the undiagnosed population; international adaptation; education; intervention combinations; transgender; sex-workers; heterosexuals and older age groups. Other research recommendations: develop the classification system further and investigate transferability of the matrix to other prevention areas

Time-resolved analysis of particle emissions from residential biomass combustion - Emissions of refractory black carbon, PAHs and organic tracers

Science.gov (United States)

Nielsen, Ingeborg E.; Eriksson, Axel C.; Lindgren, Robert; Martinsson, Johan; Nyström, Robin; Nordin, Erik Z.; Sadiktsis, Ioannis; Boman, Christoffer; Nøjgaard, Jacob K.; Pagels, Joakim

2017-09-01

Time-resolved particle emissions from a conventional wood stove were investigated with aerosol mass spectrometry to provide links between combustion conditions, emission factors, mixing state of refractory black carbon and implications for organic tracer methods. The addition of a new batch of fuel results in low temperature pyrolysis as the fuel heats up, resulting in strong, short-lived, variable emission peaks of organic aerosol-containing markers of anhydrous sugars, such as levoglucosan (fragment at m/z 60). Flaming combustion results in emissions dominated by refractory black carbon co-emitted with minor fractions of organic aerosol and markers of anhydrous sugars. Full cycle emissions are an external mixture of larger organic aerosol-dominated and smaller thinly coated refractory black carbon particles. A very high burn rate results in increased full cycle mass emission factors of 66, 2.7, 2.8 and 1.3 for particulate polycyclic aromatic hydrocarbons, refractory black carbon, total organic aerosol and m/z 60, respectively, compared to nominal burn rate. Polycyclic aromatic hydrocarbons are primarily associated with refractory black carbon-containing particles. We hypothesize that at very high burn rates, the central parts of the combustion zone become air starved, leading to a locally reduced combustion temperature that reduces the conversion rates from polycyclic aromatic hydrocarbons to refractory black carbon. This facilitates a strong increase of polycyclic aromatic hydrocarbons emissions. At nominal burn rates, full cycle emissions based on m/z 60 correlate well with organic aerosol, refractory black carbon and particulate matter. However, at higher burn rates, m/z 60 does not correlate with increased emissions of polycyclic aromatic hydrocarbons, refractory black carbon and organic aerosol in the flaming phase. The new knowledge can be used to advance source apportionment studies, reduce emissions of genotoxic compounds and model the climate impacts of

Inclusive Education in Italy: Description and Reflections on Full Inclusion

Science.gov (United States)

Anastasiou, Dimitris; Kauffman, James M.; Di Nuovo, Santo

2015-01-01

Inclusion of students with disabilities when appropriate is an important goal of special education for students with special needs. Full inclusion, meaning no education for any child in a separate setting, is held to be desirable by some, and Italy is likely the nation with an education system most closely approximating full inclusion on the…

Removal of Refractory Organics from Biologically Treated Landfill Leachate by Microwave Discharge Electrodeless Lamp Assisted Fenton Process

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Jiuyi Li

2015-01-01

Full Text Available Biologically treated leachate usually contains considerable amount of refractory organics and trace concentrations of xenobiotic pollutants. Removal of refractory organics from biologically treated landfill leachate by a novel microwave discharge electrodeless lamp (MDEL assisted Fenton process was investigated in the present study in comparison to conventional Fenton and ultraviolet Fenton processes. Conventional Fenton and ultraviolet Fenton processes could substantially remove up to 70% of the refractory organics in a membrane bioreactor treated leachate. MDEL assisted Fenton process achieved excellent removal performance of the refractory components, and the effluent chemical oxygen demand concentration was lower than 100 mg L−1. Most organic matters were transformed into smaller compounds with molecular weights less than 1000 Da. Ten different polycyclic aromatic hydrocarbons were detected in the biologically treated leachate, most of which were effectively removed by MDEL-Fenton treatment. MDEL-Fenton process provides powerful capability in degradation of refractory and xenobiotic organic pollutants in landfill leachate and could be adopted as a single-stage polishing process for biologically treated landfill leachate to meet the stringent discharge limit.

Two-Sided Estimates of Thermo-elastic Characteristics of Dispersed Inclusion Composites

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V. S. Zarubin

2015-01-01

Full Text Available The composites, dispersion-reinforced with inclusions from high-strength and high-modulus materials are widely used in technology. Nanostructure elements can perform the role of such inclusions as well. Possible applications of such composites in heat-stressed structures under heavy mechanical and thermal influences significantly depend on a complex of thermo-mechanical characteristics including the values of the moduli of elasticity and coefficient of linear thermal expansion. There are different approaches to construction of mathematical models that allow calculating dependences to estimate elastic characteristics of composites. Relation between thermoelastic properties of matrix and inclusions of the composite with its temperature coefficient of linear expansion is studied in less detail. Thus, attention has been insufficient in estimating a degree of reliability and a possible error of derived dependencies.A dual variation formulation of the problem of thermo-elasticity in a non-uniform solids simulating the properties and structure of the composite with dispersed inclusions, makes it possible to define two-sided limits of possible values of the volume elasticity modulus, shear modulus, and coefficient of linear thermal expansion of such composite. These limits allow us to estimate the maximum possible error, if to take a half-sum of the limit values of these parameters as the thermoelastic characteristics of the composite. Implementing this approach to find possible errors, arising when using one or another calculating dependency, improves reliability of predicted thermo-elastic characteristics as applied to existing and promising composites.